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32,245 full-text articles. Page 7 of 894.

Quasi-One-Dimensional Magnetism In The Spin-1/2 Antiferromagnet Bana2 Cu (Vo4)2, Sebin J. Sebastian, K. Somesh, M. Nandi, N. Ahmed, P. Bag, M. Baenitz, B. Koo, J. Sichelschmidt, A. A. Tsirlin, Yuji Furukawa, R. Nath 2021 Indian Institute of Science Education and Research

Quasi-One-Dimensional Magnetism In The Spin-1/2 Antiferromagnet Bana2 Cu (Vo4)2, Sebin J. Sebastian, K. Somesh, M. Nandi, N. Ahmed, P. Bag, M. Baenitz, B. Koo, J. Sichelschmidt, A. A. Tsirlin, Yuji Furukawa, R. Nath

Ames Laboratory Accepted Manuscripts

We report synthesis and magnetic properties of quasi-one-dimensional spin-12 Heisenberg antiferromagnetic chain compound BaNa2Cu(VO4)2. This orthovanadate has a centrosymmetric crystal structure, C2/c, where the magnetic Cu2+ ions form spin chains. These chains are arranged in layers, with the chain direction changing by 62∘ between the two successive layers. Alternatively, the spin lattice can be viewed as anisotropic triangular layers upon taking the interchain interactions into consideration. Despite this potential structural complexity, temperature-dependent magnetic susceptibility, heat capacity, electron spin resonance intensity, and nuclear magnetic resonance (NMR) shift agree well with the uniform spin-1/2 Heisenberg chain model with ...


Temperature Dependence Of London Penetration Depth Anisotropy In Superconductors With Anisotropic Order Parameters, Vladimir G. Kogan, Ruslan Prozorov 2021 Ames Laboratory

Temperature Dependence Of London Penetration Depth Anisotropy In Superconductors With Anisotropic Order Parameters, Vladimir G. Kogan, Ruslan Prozorov

Ames Laboratory Accepted Manuscripts

We study the effects of anisotropic order parameters on the temperature dependence of London penetration depth anisotropy γ λ ( T ) . After MgB 2 , this dependence is commonly attributed to distinct gaps on multiband Fermi surfaces in superconductors. We have found, however, that the anisotropy parameter may depend on temperature also in one-band materials with anisotropic order parameters Δ ( T , k F ) ; a few such examples are given. We have also found that for different order parameters, the temperature dependence of Δ ( T ) / Δ ( 0 ) can be represented with good accuracy by the interpolation suggested by Einzel [J. Low Temp. Phys ...


Cfd Simulations Of Stirred-Tank Reactors For Gas-Liquid And Gas-Liquid-Solid Systems Using Openfoam®, Xiaofei Hu, Aziz Dogan Ilgun, Alberto Passalacqua, Rodney O. Fox, Francesco Bertola, Miran Milosevic, Frans Visscher 2021 Iowa State University

Cfd Simulations Of Stirred-Tank Reactors For Gas-Liquid And Gas-Liquid-Solid Systems Using Openfoam®, Xiaofei Hu, Aziz Dogan Ilgun, Alberto Passalacqua, Rodney O. Fox, Francesco Bertola, Miran Milosevic, Frans Visscher

Chemical and Biological Engineering Publications

An open-source CFD software OpenFOAM® is used to simulate two multiphase stirred-tank reactors relevant to industrial processes such as slurry polymerization and fuel production. Gas-liquid simulations are first performed in a single-impeller stirred-tank reactor, studied experimentally by Ford, J. J., T. J. Heindel, T. C. Jensen, and J. B. Drake. 2008. “X-Ray Computed Tomography of a Gas-Sparged Stirred-Tank Reactor.” Chemical Engineering Science 63: 2075–85. Three impeller rotation speeds (200, 350 and 700 rpm) with three different bubble diameters (0.5, 1.5 and 2.5 mm) are investigated. Flow patterns compared qualitatively to those from experiments. Compared to the ...


Formation Of Short-Range Magnetic Order And Avoided Ferromagnetic Quantum Criticality In Pressurized Lacrge3, Elena Gati, John M. Wilde, Rustem Khasanov, Li Xiang, Sachith Dissanayake, Ritu Gupta, Masaaki Matsuda, Feng Ye, Bianca Haberl, Udhara Kaluarachchi, Robert J. McQueeney, Andreas Kreyssig, Sergey L. Bud’ko, Paul C. Canfield 2021 Iowa State University and Ames Laboratory

Formation Of Short-Range Magnetic Order And Avoided Ferromagnetic Quantum Criticality In Pressurized Lacrge3, Elena Gati, John M. Wilde, Rustem Khasanov, Li Xiang, Sachith Dissanayake, Ritu Gupta, Masaaki Matsuda, Feng Ye, Bianca Haberl, Udhara Kaluarachchi, Robert J. Mcqueeney, Andreas Kreyssig, Sergey L. Bud’Ko, Paul C. Canfield

Ames Laboratory Accepted Manuscripts

LaCrGe3 has attracted attention as a paradigm example of the avoidance of ferromagnetic (FM) quantum criticality in an itinerant magnet. Here, we combined thermodynamic (specific heat and thermal expansion), transport, x-ray, and neutron scattering as well as μSR measurements to obtain insights on the temperature-pressure phase diagram of LaCrGe3. Consistent with previous studies of the phase diagram by transport measurements, our thermodynamic data shows clearly that the FM transition at TFM changes its character from second order to first order when it is suppressed to low temperatures by pressure. In addition, previous studies demonstrated that for high pressures a new ...


Studies Of The Tilts Of Atmospheric Scatterers By Windprofiler Radars, Farnoush Attarzadeh 2021 The University of Western Ontario

Studies Of The Tilts Of Atmospheric Scatterers By Windprofiler Radars, Farnoush Attarzadeh

Electronic Thesis and Dissertation Repository

MST (Mesosphere–Stratosphere–Troposphere) radars are powerful instruments for observing the differences in refractive indexes in the air. By tracking refractive index perturbations, these radars can determine wind speeds and turbulence strengths in the atmosphere from the ground up to 15 km altitude. In this project, we used 6 Doppler Radars to study the correlation between horizontal and vertical winds in the Troposphere to find scatterer tilts. However, instrumental effects due to small tilts in the radar beam can also cause such correlations, thus our studies cover that as well. Scatterers are best known for being the result of turbulence ...


Study Of Structural, Transport And Magneto-Crystalline Anisotropy In La1−Xsrxmno3 (0.30 ≤ X ≤ 0.40) Perovskite Manganites, Ganesha Channagoudra, Shalabh Gupta, Vijaylakshmi Dayal 2021 Maharaja Institute of Technology Mysore

Study Of Structural, Transport And Magneto-Crystalline Anisotropy In La1−Xsrxmno3 (0.30 ≤ X ≤ 0.40) Perovskite Manganites, Ganesha Channagoudra, Shalabh Gupta, Vijaylakshmi Dayal

Ames Laboratory Accepted Manuscripts

In this paper we present structural, transport, magnetic and magneto-crystalline anisotropy of La1−xSrxMnO3 (х = 0.30, 0.33, 0.36, and 0.40) synthesized using the solid-state reaction method. The X-ray diffraction pattern of the samples is well indexed to the rhombohedral structure with R3c space group. Lattice parameters and unit cell volume are found to decrease monotonically upon increasing Sr2+ concentration at La3+ site. X-ray photoelectron spectroscopy confirms the presence of Mn4+ and Mn3+, the ratio of which (Mn4+/Mn3+) increases from 0.44 to 0.64 with increasing Sr2+ concentration. From the ρ(T) and M(T ...


Euler, Father Of Haemodynamics, Sylvio R. Bistafa 2021 University of Sao Paulo

Euler, Father Of Haemodynamics, Sylvio R. Bistafa

Euleriana

This article is being published in conjunction with the translation and synopsis of E855. Principia pro motu sanguinis per arterias determinando of 1775 - view the translation and synopsis by clicking here.


Ir Finite S-Matrix By Gauge Invariant Dressed States, Hayato Hirai, Sotaro Sugishita 2021 National Institute of Technology, Japan

Ir Finite S-Matrix By Gauge Invariant Dressed States, Hayato Hirai, Sotaro Sugishita

Physics and Astronomy Faculty Publications

Dressed states were proposed to define the infrared (IR) finite S-matrix in QED or gravity. We show that the original Kulish-Faddeev dressed states are not enough to cure the IR divergences. To illustrate this problem, we consider QED with background currents (Wilson lines). This theory is exactly solvable but shares the same IR problems as the full QED. We show that naive asymptotic states lead to IR divergences in the S-matrix and are also inconsistent with the asymptotic symmetry, even if we add the original Kulish-Faddeev dressing operators. We then propose new dressed states which are consistent with ...


Scalable, Cost-Efficient Synthesis And Properties Optimization Of Magnetoelectric Cobalt Ferrite/Barium Titanate Composites, Farnaz Safi Samghabadi, Long Chang, Mohammad Khodadadi, Karen S. Martirosyan, Dmitri Litvinov 2021 The University of Texas Rio Grande Valley

Scalable, Cost-Efficient Synthesis And Properties Optimization Of Magnetoelectric Cobalt Ferrite/Barium Titanate Composites, Farnaz Safi Samghabadi, Long Chang, Mohammad Khodadadi, Karen S. Martirosyan, Dmitri Litvinov

Physics and Astronomy Faculty Publications and Presentations

Cobalt ferrite (CoFe2O4)/barium titanate (BaTiO3) particulate composites exhibiting high magnetoelectric coefficients were synthesized from low-cost commercial precursors using mechanical ball milling followed by high-temperature annealing. CoFe2O4 (20 nm–50 nm) and either cubic or tetragonal BaTiO3 nanoparticle powders were used for the synthesis. It was found that utilizing a 50nm cubic BaTiO3 powder as a precursor results in a composite with a magnetoelectric coupling coefficient value as high as 4.3 mV/Oe cm, which is comparable to those of chemically synthesized core–shell CoFe2O4–BaTiO3 nanoparticles. The microstructure of these composites is dramatically different from the composite synthesized ...


Manipulation Of Electronic Property Of Epitaxial Graphene On Sic Substrate By Pb Intercalation, Jinjin Wang, Minsung Kim, Liangyao Chen, Kai-Ming Ho, Michael C. Tringides, Cai-Zhuang Wang, Songyou Wang 2021 Fudan University, Ames Laboratory, and Iowa State University

Manipulation Of Electronic Property Of Epitaxial Graphene On Sic Substrate By Pb Intercalation, Jinjin Wang, Minsung Kim, Liangyao Chen, Kai-Ming Ho, Michael C. Tringides, Cai-Zhuang Wang, Songyou Wang

Ames Laboratory Accepted Manuscripts

Manipulating the electronic properties of graphene has been a subject of great interest since it can aid material design to extend the applications of graphene to many different areas. In this paper, we systematically investigate the effect of lead (Pb) intercalation on the structural and electronic properties of epitaxial graphene on the SiC(0001) substrate. We show that the band structure of Pb-intercalated few-layer graphene can be effectively tuned through changing intercalation conditions, such as coverage, location of Pb, and the initial number of graphene layers. Lead intercalation at the interface between the buffer layer (BL) and the SiC substrate ...


Scalable, Cost-Efficient Synthesis And Properties Optimization Of Magnetoelectric Cobalt Ferrite/Barium Titanate Composites, Farnaz Safi Samghabadi, Long Chang, Mohammad Khodadadi, Karen S. Martirosyan, Dmitri Litvinov 2021 The University of Texas Rio Grande Valley

Scalable, Cost-Efficient Synthesis And Properties Optimization Of Magnetoelectric Cobalt Ferrite/Barium Titanate Composites, Farnaz Safi Samghabadi, Long Chang, Mohammad Khodadadi, Karen S. Martirosyan, Dmitri Litvinov

Physics and Astronomy Faculty Publications and Presentations

Cobalt ferrite (CoFe2O4)/barium titanate (BaTiO3) particulate composites exhibiting high magnetoelectric coefficients were synthesized from low-cost commercial precursors using mechanical ball milling followed by high-temperature annealing. CoFe2O4 (20 nm–50 nm) and either cubic or tetragonal BaTiO3 nanoparticle powders were used for the synthesis. It was found that utilizing a 50nm cubic BaTiO3 powder as a precursor results in a composite with a magnetoelectric coupling coefficient value as high as 4.3 mV/Oe cm, which is comparable to those of chemically synthesized core–shell CoFe2O4–BaTiO3 nanoparticles. The microstructure of these composites is dramatically different from the composite synthesized ...


Computational Modelling Enables Robust Multidimensional Nanoscopy, Matthew D. Lew 2021 Washington University in St. Louis

Computational Modelling Enables Robust Multidimensional Nanoscopy, Matthew D. Lew

Electrical & Systems Engineering Publications and Presentations

The following sections are included:

  • Present State of Computational Modelling in Fluorescence Nanoscopy

  • Recent Contributions to Computational Modelling in Fluorescence Nanoscopy

  • Outlook on Computational Modelling in Fluorescence Nanoscopy

  • Acknowledgments

  • References


Plasmonic Waveguides To Enhance Quantum Electrodynamic Phenomena At The Nanoscale, Ying Li, Christos Argyropoulos 2021 Nanjing University of Information Science and Technology

Plasmonic Waveguides To Enhance Quantum Electrodynamic Phenomena At The Nanoscale, Ying Li, Christos Argyropoulos

Faculty Publications from the Department of Electrical and Computer Engineering

The emerging field of plasmonics can lead to enhanced light-matter interactions at extremely nanoscale regions. Plasmonic (metallic) devices promise to efficiently control both classical and quantum properties of light. Plasmonic waveguides are usually used to excite confined electromagnetic modes at the nanoscale that can strongly interact with matter. The analysis of these nanowaveguides exhibits similarities with their low frequency microwave counterparts. In this article, we review ways to study plasmonic nanostructures coupled to quantum optical emitters from a classical electromagnetic perspective. These quantum emitters are mainly used to generate single-photon quantum light that can be employed as a quantum bit ...


The Structure Function Relationship Of Disordered Networks Using Young's Modulus And Floppy Modes, Melinda Grace Tajnai 2021 California Polytechnic State University, San Luis Obispo

The Structure Function Relationship Of Disordered Networks Using Young's Modulus And Floppy Modes, Melinda Grace Tajnai

Physics

Disordered networks may have the ability to store information that can be retrieved using a Young’s modulus measurement. The effect of the number of floppy modes a network has on the value of this Young’s modulus measurement is unknown. This experiment uses 28 networks consisting of 3D printed edges in a sliding frame to determine how the Young’s modulus of a network is related to the number of floppy modes.


Gutzwiller Hybrid Quantum-Classical Computing Approach For Correlated Materials, Yongxin Yao, Feng Zhang, Cai-Zhuang Wang, Kai-Ming Ho, Peter P. Orth 2021 Iowa State University and Ames Laboratory

Gutzwiller Hybrid Quantum-Classical Computing Approach For Correlated Materials, Yongxin Yao, Feng Zhang, Cai-Zhuang Wang, Kai-Ming Ho, Peter P. Orth

Physics and Astronomy Publications

Rapid progress in noisy intermediate-scale quantum (NISQ) computing technology has led to the development of novel resource-efficient hybrid quantum-classical algorithms, such as the variational quantum eigensolver (VQE), that can address open challenges in quantum chemistry, physics, and material science. Proof-of-principle quantum chemistry simulations for small molecules have been demonstrated on NISQ devices. While several approaches have been theoretically proposed for correlated materials, NISQ simulations of interacting periodic models on current quantum devices have not yet been demonstrated. Here, we develop a hybrid quantum-classical simulation framework for correlated electron systems based on the Gutzwiller variational embedding approach. We implement this framework ...


Expansive Open Fermi Arcs And Connectivity Changes Induced By Infrared Phonons In Zrte5, Lin-Lin Wang 2021 Ames Laboratory

Expansive Open Fermi Arcs And Connectivity Changes Induced By Infrared Phonons In Zrte5, Lin-Lin Wang

Ames Laboratory Accepted Manuscripts

Expansive open Fermi arcs covering most of the surface Brillouin zone (SBZ) are desirable for detection and control of many topological phenomena, but they have generally been reported for Kramers-Weyl points, or unconventional chiral fermions, pinned at time-reversal invariant momentum in chiral materials. Here using first-principles band structure calculations, we show that for conventional Weyl points in ZrTe5 with the chirality of +1/−1 near the BZ center at general momentum induced by one of the infrared phonons—the second lowest B1u mode for breaking inversion symmetry—they can also form expansive open Fermi arcs across the SBZ boundary to ...


Role Of Protonation State Changes And Hydrogen Bonding Around The Oxygen Evolving Complex Of Photosystem Ii, Divya Matta 2021 The Graduate Center, City University of New York

Role Of Protonation State Changes And Hydrogen Bonding Around The Oxygen Evolving Complex Of Photosystem Ii, Divya Matta

Dissertations, Theses, and Capstone Projects

The mechanism of natural photosynthesis involves the use of solar energy to produce O2 we breathe and food and fuel we intake. This process results in the biological oxidation of water that takes place at room temperature, neutral pH using earth abundant elements Ca and Mn. Understanding how this challenging chemical reaction occurs in photosynthesis can be useful for designing better artificial photosynthetic complexes that can be used as biofuels. My doctoral work is to study the deprotonation and oxidation events elucidating the mechanistic details of proton coupled electron transfer reaction in a photosynthetic protein.

The O2 evolution ...


Third Harmonic Generation: A Method For Visualizing Myelin In The Murine Cerebral Cortex, Michael Redlich 2021 The Graduate Center, City University of New York

Third Harmonic Generation: A Method For Visualizing Myelin In The Murine Cerebral Cortex, Michael Redlich

Dissertations, Theses, and Capstone Projects

Here we present the use of Third Harmonic Generation (THG) for the label-free imaging of myelinated axons in the murine cerebral cortex. Myelin plays an important role in the processes of learning and disease. However, much of the myelin biology research thus far has focused on white matter tracts where myelin is more visible. Much is still unknown, particularly with regard to myelin in gray matter. First, we engage in THG microscopy using an optical parametric oscillator pumped by a titanium-sapphire laser to demonstrate the utility of the technique for imaging myelin in vivo. Second, we investigate the use of ...


Na Lidar And Mighti/Icon Investigation On Turbopause Tidal Waves, Tao Yuan, Michael H. Stevens, Christoph R. Englert, Thomas J. Immel 2021 Utah State University

Na Lidar And Mighti/Icon Investigation On Turbopause Tidal Waves, Tao Yuan, Michael H. Stevens, Christoph R. Englert, Thomas J. Immel

Browse all Datasets

Local full diurnal coverage of temperature variations across the turbopause (~ 90 km to 115 km altitude) is achieved by combining the nocturnal observations of a Sodium (Na) Doppler lidar on the Utah State University (USU) campus (41.7?N, 248.2?E) and NASA MIGHTI/ICON daytime observations made in the same vicinity. In this paper, utilizing this hybrid dataset during summer 2020 between June 12th and July 15th, we retrieve the temperature signatures of diurnal and semidiurnal tidal waves in this region. The tidal amplitudes are similar for both components: less than 5 K below ~ 98 km but increase ...


Interactions Of Organic Fluorophores With Plasmonic Surface Lattice Resonances, Robert J. Collison 2021 The Graduate Center, City University of New York

Interactions Of Organic Fluorophores With Plasmonic Surface Lattice Resonances, Robert J. Collison

Dissertations, Theses, and Capstone Projects

It is common knowledge that metals, alloys and pure elements alike, are lustrous and reflective, the more so when a metal surface is flat, polished, and free from oxidation and surface fouling. However, some metals reflect visible light, in the 380 nm to 740 nm range of wavelengths, much more strongly than others. In particular, some metals reflect wavelengths in certain portions of the ultraviolet (UV), visible, and near-infrared (NIR) regime, let us say 200 nm to 2000 nm, while absorbing light strongly in other segments of this range. There are several factors that account for this difference between various ...


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