2,572 research outputs found
Evaluation of the Bond Stress Transfer Mechanism in CFSTs
This paper studies the non-linear distribution of bond–slip behavior in the steel concrete interface of a Concrete Filled Steel Tube (CFST). Specifically, it concerns the regions of geometric discontinuity occurring in composite beams of CFST column-frame connection points. The study was conducted through an analytical model that represented the bond stress transfer mechanism within these areas. The resulting deductions were drawn up on the basis of the elasticity theory and the non-linear bond–slip relationship between the steel jacket and the confined concrete. This paper highlights how the model proposed here was able to obtain, not only the closed-form analytical expression of the transferring length involved in the bond stress transfer mechanism in CFSTs but also the expressions of concrete and steel jacket stresses and strains. In addition, the procedure also obtained the bond stress and slip trend in the above-mentioned length for rectangular and circular concrete filled steel tubes. The use of this model also resulted in an analytical expression for the calculation of the ultimate load in CFSTs. In this paper, the ultimate load predictions were compared with the experimental results obtained from 97 tests carried out on circular concrete filled tubes (CCFTs) and 35 tests on rectangular concrete filled tubes (RCFTs). The predictions drawn up with this model have been found to be the most accurate and uniform in comparison with those obtained from models proposed by other authors and Eurocode. With reference to the experimental-to-analytical load value ratio, the AVG and COV values obtained from the model proposed here are 0.86 and 0.42, and 1.06 and 0.57 for CCFT and RCFT analyses, respectively
Correlative analysis of interaction between recrystallization and precipitation during sub-critical annealing of cold-rolled low-carbon V and Ti–V bearing microalloyed steels
In this paper a new insight into fundamentals of static recrystallization, precipitation and their interaction during sub-critical annealing of three cold-rolled low-carbon microalloyed steel grades is presented. The grades under investigation are a base grade containing V as a microalloying element, a Ti+ grade containing Ti as microalloying element added into the base grade, and a Ti+Mn+ grade containing additional Mn added into the Ti+ grade. The cold-rolled steels are sub-critically annealed inside a muffle furnace to simulate industrial continuous annealing parameters in order to investigate the interaction between recrystallization and precipitation across transient stages of the annealing process as a function of temperature and time. The Zener pinning of precipitates and solute drag force of Mn on the recrystallization process are calculated and compared with measured values obtained from experimental studies on the recrystallization kinetics. Results suggest that the recrystallization kinetics is fastest in the base grade. For the Ti+ grade, fine (< 15 nm) (Ti,V)(C/N) particles retard the recrystallization kinetics. For the Ti+ and Ti+Mn+ grades, solute drag effect of Mn solute atoms for dwell time longer than 2 min at annealing temperature of 800 oC is negligible
Investigating nano-precipitation in a V-containing HSLA steel using small angle neutron scattering
Interphase precipitation (IPP) of nanoscale carbides in a vanadium-containing high-strength low-alloy steel has been investigated. Small angle neutron scattering (SANS) and transmission electron microscopy (TEM) were employed to characterize the precipitates and their size distributions in Fe-0.047C-0.2V-1.6Mn (in wt.%) alloy samples which had been austenitized, isothermally transformed at 700 °C for between 3 and 600 min and water quenched. TEM confirms that, following heat treatment, rows of vanadium-containing nanoscale interphase precipitates were present. Model-independent analysis of the nuclear SANS signal and model fitting calculations, using oblate spheroid and disc-shapes, were performed. The major axis diameter increased from 18 nm after 3 min to 35 nm after 600 min. Precipitate volume percent increased from 0.09 to 0.22 vol% over the same period and number density fell from 2 × 1021 to 5 × 1020 m−3. A limited number of measurements of precipitate maximum diameters from TEM images showed the mean value increased from 8 nm after 5 min to 28 nm after 600 min which is in reasonable agreement with the SANS data
Representativeness of European biochar research : Part I - field experiments
A representativeness survey of existing European Biochar field experiments within the Biochar COST Action TD1107 was conducted to gather key information for setting up future experiments and collaborations, and to minimise duplication of efforts amongst European researchers. Woody feedstock biochar, applied without organic or inorganic fertiliser appears over-represented compared to other categories, especially considering the availability of crop residues, manures, and other organic waste streams and the efforts towards achieving a zero waste economy. Fertile arable soils were also over-represented while shallow unfertile soils were under-represented. Many of the latter are likely in agroforestry or forest plantation land use. The most studied theme was crop production. However, other themes that can provide evidence of mechanisms, as well as potential undesired side-effects, were relatively well represented. Biochar use for soil contamination remediation was the least represented theme; further work is needed to identify which specific contaminants, or mixtures of contaminants, have the potential for remediation by different biochars.Peer reviewe
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Representativeness of European biochar research: part I–field experiments
A representativeness survey of existing European Biochar field experiments within the Biochar COST Action TD1107 was conducted to gather key information for setting up future experiments and collaborations, and to minimise duplication of efforts amongst European researchers. Woody feedstock biochar, applied without organic or inorganic fertiliser appears over-represented compared to other categories, especially considering the availability of crop residues, manures, and other organic waste streams and the efforts towards achieving a zero waste economy. Fertile arable soils were also over-represented while shallow unfertile soils were under-represented. Many of the latter are likely in agroforestry or forest plantation land use. The most studied theme was crop production. However, other themes that can provide evidence of mechanisms, as well as potential undesired side-effects, were relatively well represented. Biochar use for soil contamination remediation was the least represented theme; further work is needed to identify which specific contaminants, or mixtures of contaminants, have the potential for remediation by different biochars. © 2017 The Author(s) Published by VGTU Press and Informa UK Limited, [trading as Taylor & Francis Group]
SF3B1-mutated chronic lymphocytic leukemia shows evidence of NOTCH1 pathway activation including CD20 downregulation
Chronic lymphocytic leukemia (CLL) is characterized by a low CD20 expression, in part explained by an epigenetic-driven downregulation triggered by mutations of the NOTCH1 gene. In the present study, by taking advantage of a wide and well-characterized CLL cohort (n=537), we demonstrate that CD20 expression is downregulated in SF3B1-mutated CLL in an extent similar to NOTCH1-mutated CLL. In fact, SF3B1-mutated CLL cells show common features with NOTCH1-mutated CLL cells, including a gene expression profile enriched of NOTCH1-related gene sets and elevated expression of the active intracytoplasmic NOTCH1. Activation of the NOTCH1 signaling and down-regulation of surface CD20 in SF3B1-mutated CLL cells correlate with over-expression of an alternatively spliced form of DVL2, a component of the Wnt pathway and negative regulator of the NOTCH1 pathway. These findings are confirmed by separately analyzing the CD20-dim and CD20-bright cell fractions from SF3B1-mutated cases as well as by DVL2 knock-out experiments in CLL-like cell models. Altogether, the clinical and biological features that characterize NOTCH1-mutated CLL may also be recapitulated in SF3B1-mutated CLL, contributing to explain the poor prognosis of this CLL subset and providing the rationale for expanding novel agents-based therapies to SF3B1-mutated CLL
Bioinformatics
Motivation: Theoretical efforts to understand the regulation of gene expression are traditionally centered around the identification of transcription factor binding sites at specific DNA positions. More recently these efforts have been supplemented by experimental data for relative binding affinities of proteins to longer intergenic sequences. The question arises to what extent these two approaches converge. In this paper, we adopt a physical binding model to predict the relative binding affinity of a transcription factor for a given sequence. Results: We find that a significant fraction of genome-wide binding data in yeast can be accounted for by simple count matrices and a physical model with only two parameters. We demonstrate that our approach is both conceptually and practically more powerful than traditional methods, which require selection of a cutoff. Our analysis yields biologically meaningful parameters, suitable for predicting relative binding affinities in the absence of experimental binding data. Availability: The C source code for our TRAP program is freely available for non-commercial use at http://www.molgen.mpg.de/~manke/papers/TFaffinities
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Search for MSSM Higgs bosons decaying to μ+μ-in proton-proton collisions at √s=13TeV
A search is performed for neutral non-standard-model Higgs bosons decaying to two muons in the context of the minimal supersymmetric standard model (MSSM). Proton-proton collision data recorded by the CMS experiment at the CERN Large Hadron Collider at a center-of-mass energy of 13TeVwere used, corresponding to an integrated luminosity of 35.9fb-1. The search is sensitive to neutral Higgs bosons produced via the gluon fusion process or in association with a bbquark pair. No significant deviations from the standard model expectation are observed. Upper limits at 95% confidence level are set in the context of the mmod+hand phenomenological MSSM scenarios on the parameter tanβas a function of the mass of the pseudoscalar Aboson, in the range from 130 to 600GeV. The results are also used to set a model-independent limit on the product of the branching fraction for the decay into a muon pair and the cross section for the production of a scalar neutral boson, either via gluon fusion, or in association with bquarks, in the mass range from 130 to 1000GeV
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Studies of Bs2∗(5840)0 and Bs1(5830)0 mesons including the observation of the Bs2∗(5840)0→B0KS0 decay in proton-proton collisions at s=8TeV.
Measurements of Bs2∗(5840)0 and Bs1(5830)0 mesons are performed using a data sample of proton-proton collisions corresponding to an integrated luminosity of , collected with the CMS detector at the LHC at a centre-of-mass energy of 8TeV . The analysis studies P-wave Bs0 meson decays into B(∗)+K- and B(∗)0KS0 , where the B+ and B0 mesons are identified using the decays B+→J/ψK+ and B0→J/ψK∗(892)0 . The masses of the P-wave Bs0 meson states are measured and the natural width of the Bs2∗(5840)0 state is determined. The first measurement of the mass difference between the charged and neutral B∗ mesons is also presented. The Bs2∗(5840)0 decay to B0KS0 is observed, together with a measurement of its branching fraction relative to the Bs2∗(5840)0→B+K- decay
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