Rope formation for gas solid flow in a 90 degree bend with varying particle size distributions

Paper presented to the 10th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Florida, 14-16 July 2014.Pneumatic conveying, the process of transporting particulate materials through pipelines with gas as the carrier, is a commonly-used means of material transport in industry. In order to simplify the layout of the plant, the materials are frequently transported through ducts with numerous bends and pipe sections. For instance, coal-fired power plants operate on a continuous supply of pulverised coal which is transported from the mill through these ducts. The piping used in these transport systems commonly includes bends that have a significant effect on the gas-solid flow structure. As a result of centrifugal forces within these pipe bends, the gas and solid particles segregate and the particles form a dense structure known as a rope. This region has relatively high particle concentration. Additionally, deposition of particles occurs due to deceleration of particles. These particle behaviors lead to difficulties for plant operators in maintaining optimal conditions for combustion in furnaces as a result of irregularities in the pulverised fuel supply. Experimental studies have been conducted in a 90-degree vertical-to-horizontal pipe bend. The solid particles used in this study are high density polyethylene (HDPE) beads and ground flaxseed, with diameters ranging from 686 to 1171 microns, and with a mean diameter of 871 microns. The particle densities are 0.86g/cc and 1.2g/cc respectively. Experiments have been performed for a range of gas velocities and solids loadings, and the results of these experiments show that the particles form a thick rope at high solids loadings. The rope formation conditions for the different particle size distributions were analysed and computational fluid dynamics (CFD) simulations are performed to supplement the experiments. Preliminary comparisons between the experimental and CFD simulation results show that both the flaxseed and HDPE particles exhibit a roping behaviour at solids loadings as low as 0.4; however, experimental results indicate that only the flaxseed exhibits roping at this loading. The reasons for this unexpected behaviour are being investigated.dc201

Comparison of flow and dispersion properties of free and wall turbulent jets for source dynamics characterisation

The objective of this paper is to provide an investigation, using large eddy simulations, into the dispersion of aircraft jets in co-flowing take-off conditions. Before carrying out such study, simple turbulent plane free and wall jet simulations are carried out to validate the computational models and to assess the impact of the presence of the solid boundary on the flow and dispersion properties. The current study represents a step towards a better understanding of the source dynamics behind an airplane jet engine during the take-off and landing phases. The information provided from these simulations can be used for future improvements of existing dispersion models

Fine-Scale Mapping of the 4q24 Locus Identifies Two Independent Loci Associated with Breast Cancer Risk

Background: A recent association study identified a common variant (rs9790517) at 4q24 to be associated with breast cancer risk. Independent association signals and potential functional variants in this locus have not been explored. Methods: We conducted a fine-mapping analysis in 55,540 breast cancer cases and 51,168 controls from the Breast Cancer Association Consortium. Results: Conditional analyses identified two independent association signals among women of European ancestry, represented by rs9790517 [conditional P = 2.51 × 10−4; OR, 1.04; 95% confidence interval (CI), 1.02–1.07] and rs77928427 (P = 1.86 × 10−4; OR, 1.04; 95% CI, 1.02–1.07). Functional annotation using data from the Encyclopedia of DNA Elements (ENCODE) project revealed two putative functional variants, rs62331150 and rs73838678 in linkage disequilibrium (LD) with rs9790517 (r2 ≥ 0.90) residing in the active promoter or enhancer, respectively, of the nearest gene, TET2. Both variants are located in DNase I hypersensitivity and transcription factor–binding sites. Using data from both The Cancer Genome Atlas (TCGA) and Molecular Taxonomy of Breast Cancer International Consortium (METABRIC), we showed that rs62331150 was associated with level of expression of TET2 in breast normal and tumor tissue. Conclusion: Our study identified two independent association signals at 4q24 in relation to breast cancer risk and suggested that observed association in this locus may be mediated through the regulation of TET2. Impact: Fine-mapping study with large sample size warranted for identification of independent loci for breast cancer risk

Measurements of differential production cross sections for a Z boson in association with jets in pp collisions at root s=8 TeV

Peer reviewe

Search for leptophobic Z ' bosons decaying into four-lepton final states in proton-proton collisions at root s=8 TeV

Peer reviewe

Search for black holes and other new phenomena in high-multiplicity final states in proton-proton collisions at root s=13 TeV

Peer reviewe

Search for high-mass diphoton resonances in proton-proton collisions at 13 TeV and combination with 8 TeV search

Peer reviewe

Search for heavy resonances decaying into a vector boson and a Higgs boson in final states with charged leptons, neutrinos, and b quarks

Peer reviewe

Search for neutral resonances decaying into a Z boson and a pair of b jets or τ leptons

A search is performed for a new resonance decaying into a lighter resonance and a Z boson. Two channels are studied, targeting the decay of the lighter resonance into either a pair of oppositely charged τ leptons or a bb‾ pair. The Z boson is identified via its decays to electrons or muons. The search exploits data collected by the CMS experiment at a centre-of-mass energy of 8 TeV, corresponding to an integrated luminosity of 19.8 fb −1 . No significant deviations are observed from the standard model expectation and limits are set on production cross sections and parameters of two-Higgs-doublet models