Synthesis of the Single Phase i-AlCuFe Bulk Quasicrystal by Spray Forming

In the present study, an icosahedral single phase bulk quasicrystalline material based on Al62Cu25.5Fe12.5 has been synthesised by a spray forming route. Microstructural characterization showed an average grain size of 10 m. The oversprayed fine powder showed the presence of - and -phases, whereas, the deposit consited of the fully single phase bulk quasicrystalline material with compositional homogeneity. The hardness and fracture toughness measurements were carried out at different indentation loads of 50-500 g. The hardness values varied in the range 10.4-8.1 GPa and fracture toughness was seen to decrease with increasing load. The varionan of hardness with load, which is known as indentation size effect (ISE) has been established clearly. Fracture toughness value was constant in the load range from 200 to 500 g at 1.2 MPa.m1/2. The cracking pattern after indentation at higher has been observed to be intergranular as well as transgranular. The evolution of the single phase bulk quasicrystalline material has been discussed in light of the unique combination of atomization and deposition process elements in spray forming technique

Novel microstructural characteristics and properties of spray formed Al-RE-TM based alloys

Recent studies on the synthesis of bulk Al-RE (Rare Earth)-TM (Transition Metal) based alloys, from melt spun ribbons and gas atomized powders, have shown that a partially amorphous or nano-crystalline structures lead to a high specific strength. In the present study, therefore, spray atomization and deposition process has been used to produce plates of Al85Y8Ni5Co2 (deposit D1) and Al83Y5La5Ni5Co2 (deposit D2) based alloys so as to synthesize bulk deposit of nano-crystalline and/or partial amorphous matrix composite in a single step. The rapid solidification and high undercooling of droplets during atomization and a chilling effect on undercooled liquid upon deposition are expected to give rise to the above microstructural features. The microstructural features of deposits as well as overspray powders were studied using optical, scanning and transmission electron microscope. The alloys invariably showed a large fraction of nano-crystalline and amorphous structures, characterized by featureless regions at optical resolution, along with distribution of primary equilibrium phases. The differential scanning calorimetric (DSC) analysis of the deposits showed all the crystallization peaks as is observed during crystallization of fully amorphous melt spun ribbons of respective compositions. A glass transition phenomenon is observed in Al-Y-Ni-Co based deposit. The transmission electron microscopy of deposit D1 showed the presence of 50-100 nm size fcc-Al precipitates in an amorphous matrix decorated with 5-20 nm fcc-Al crystallites. The annealing treatment of deposits at different temperatures, determined from the crystallization peaks of the deposit, showed precipitation of nanoscale fcc-Al and intermetallic phases giving rise to a remarkable increase in hardness. The bulk hardness of the deposits D1 and D2 was 391 and 427 HV, respectively. Whereas, the heat treated deposits showed a bulk hardness value of 476 HV for deposit D1 at 298 oC and 582 HV for deposit D2 at 380 oC. An attempt has been made to bring out the possible mechanism of microstructural evolution during spray deposition of these alloys, and the effect of microstructural features on the mechanical properties has been discussed

From spin liquid to magnetic ordering in the anisotropic kagome Y-Kapellasite Y3Cu9(OH)19Cl8: a single crystal study

Y3Cu9(OH)19Cl8 realizes an original anisotropic kagome model hosting a rich magnetic phase diagram [M. Hering et al, npj Computational Materials 8, 1 (2022)]. We present an improved synthesis of large phase-pure single crystals via an external gradient method. These crystals were investigated in details by susceptibility, specific heat, thermal expansion, neutron scattering and local muSR and NMR techniques. At variance with polycristalline samples, the study of single crystals gives evidence for subtle structural instabilities at 33K and 13K which preserve the global symmetry of the system and thus the magnetic model. At 2.1K the compound shows a magnetic transition to a coplanar (1/3,1/3) long range order as predicted theoretically. However our analysis of the spin wave excitations yields magnetic interactions which locate the compound closer to the phase boundary to a classical jammed spin liquid phase. Enhanced quantum fluctuations at this boundary may be responsible for the strongly reduced ordered moment of the Cu2+, estimated to be 0.075muB from muSR

Effect of cyclosporin A on proteinuria in the course of glomerulopathy associated with WT1 mutations

Denys–Drash syndrome (DDS) is characterized by progressive glomerulopathy caused by diffuse mesangial sclerosis (DMS), genitourinary defects, and a higher risk of developing Wilms’ tumor. It is commonly assumed that the DMS is unresponsive to any medications. In this report, we present a patient with Denys–Drash syndrome, in whom the cyclosporine A (CsA) was found to induce total remission. This observation and observations of other authors confirm that in genetic forms of nephrotic syndrome, the proteinuric effect of CsA may be due to a non-immunologic mechanism. We confirm the beneficial effect of CsA treatment in DDS; however, the potential nephrotoxicity of this drug will probably not allow long-term use

Measurement of the cross-section and charge asymmetry of WW bosons produced in proton-proton collisions at s=8\sqrt{s}=8 TeV with the ATLAS detector

This paper presents measurements of the $W^+ \rightarrow \mu^+\nu$ and $W^- \rightarrow \mu^-\nu$ cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13

Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in √s=13 TeV pp collisions with the ATLAS detector

A search for supersymmetry through the pair production of electroweakinos with mass splittings near the electroweak scale and decaying via on-shell W and Z bosons is presented for a three-lepton final state. The analyzed proton-proton collision data taken at a center-of-mass energy of √s=13  TeV were collected between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 139  fb−1. A search, emulating the recursive jigsaw reconstruction technique with easily reproducible laboratory-frame variables, is performed. The two excesses observed in the 2015–2016 data recursive jigsaw analysis in the low-mass three-lepton phase space are reproduced. Results with the full data set are in agreement with the Standard Model expectations. They are interpreted to set exclusion limits at the 95% confidence level on simplified models of chargino-neutralino pair production for masses up to 345 GeV

Search for direct stau production in events with two hadronic tau-leptons in root s=13 TeV pp collisions with the ATLAS detector

A search for the direct production of the supersymmetric partners ofτ-leptons (staus) in final stateswith two hadronically decayingτ-leptons is presented. The analysis uses a dataset of pp collisions corresponding to an integrated luminosity of139fb−1, recorded with the ATLAS detector at the LargeHadron Collider at a center-of-mass energy of 13 TeV. No significant deviation from the expected StandardModel background is observed. Limits are derived in scenarios of direct production of stau pairs with eachstau decaying into the stable lightest neutralino and oneτ-lepton in simplified models where the two staumass eigenstates are degenerate. Stau masses from 120 GeV to 390 GeV are excluded at 95% confidencelevel for a massless lightest neutralino

Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente

Constraints on off-shell Higgs boson production and the Higgs boson total width in ZZ → 4` and ZZ → 2`2ν final states with the ATLAS detector

A measurement of off-shell Higgs boson production in the ZZ→4ℓ and ZZ→2ℓ2ν decay channels, where ℓ stands for either an electron or a muon, is performed using data from proton-proton collisions at a centre-of-mass energy of s=13 TeV. The data were collected by the ATLAS experiment in 2015 and 2016 at the Large Hadron Collider, and they correspond to an integrated luminosity of 36.1fb−1 . An observed (expected) upper limit on the off-shell Higgs signal strength, defined as the event yield normalised to the Standard Model prediction, of 3.8 (3.4) is obtained at 95% confidence level (CL). Assuming the ratio of the Higgs boson couplings to the Standard Model predictions is independent of the momentum transfer of the Higgs production mechanism considered in the analysis, a combination with the on-shell signal-strength measurements yields an observed (expected) 95% CL upper limit on the Higgs boson total width of 14.4 (15.2) MeV.Fil: Aaboud, M.. Université Mohamed Premier and LPTPM; MarruecosFil: Aad, G.. Aix-Marseille Université; FranciaFil: Abbott, B.. Oklahoma State University; Estados UnidosFil: Abdinov, O.. Azerbaijan Academy of Sciences; AzerbaiyánFil: Abeloos, B.. Université Paris-Saclay; FranciaFil: Alconada Verzini, María Josefina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; ArgentinaFil: Alonso, Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; ArgentinaFil: Arduh, Francisco Anuar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; ArgentinaFil: Dova, Maria Teresa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; ArgentinaFil: Hoya, Joaquín. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; ArgentinaFil: Monticelli, Fernando Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; ArgentinaFil: Wahlberg, Hernan Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; ArgentinaFil: Bossio Sola, Jonathan David. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: Daneri, María Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: Devesa, Maria Roberta. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: Marceca, Gino. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: Otero y Garzon, Gustavo Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: Piegaia, Ricardo Nestor. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: Sacerdoti, Sabrina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: Zinonos, Z.. Georg-August-Universität; AlemaniaFil: Zinser, M.. Universität Mainz; AlemaniaFil: Ziolkowski, M.. Universität Siegen; AlemaniaFil: Živković, L.. University of Belgrade; SerbiaFil: Zobernig, G.. University of Wisconsin; Estados UnidosFil: Zoccoli, A.. Università di Bologna; ItaliaFil: Zoch, K.. Georg-August-Universität; AlemaniaFil: Nedden, M. zur. Humboldt University; AlemaniaFil: Zorbas, T. G.. University of Sheffield; Reino UnidoFil: Zou, R.. University of Chicago; Estados UnidosFil: Zwalinski, L.. Cern - European Organization for Nuclear Research; SuizaFil: The ATLAS Collaboration. No especifíca

Search for R-parity-violating supersymmetric particles in multi-jet final states produced in p-p collisions at s√=13 TeV using the ATLAS detector at the LHC

Results of a search for gluino pair production with subsequent R-parity-violating decays to quarks are presented. This search uses 36.1 fb−1 of data collected by the ATLAS detector in proton–proton collisions with a center-of-mass energy of √ s = 13 TeV at the LHC. The analysis is performed using requirements on the number of jets and the number of jets tagged as containing a b-hadron as well as a topological observable formed by the scalar sum of masses of large-radius jets in the event. No significant excess above the expected Standard Model background is observed. Limits are set on the production of gluinos in models with the R-parity-violating decays of either the gluino itself (direct decay) or the neutralino produced in the R-parity-conserving gluino decay (cascade decay). In the gluino cascade decay model, gluino masses below 1850 GeV are excluded for 1000 GeV neutralino mass. For the gluino direct decay model, the 95% confidence level upper limit on the cross section times branching ratio varies between 0.80 fb at mg˜ = 900 GeV and 0.011 fb at mg˜ = 1800 GeV.Fil: Arduh, Francisco Anuar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; Argentina. Cern - European Organization For Nuclear Research; Suiz