Chiral spin-orbital liquids with nodal lines

Strongly correlated materials with strong spin-orbit coupling hold promise for realizing topological phases with fractionalized excitations. Here we propose a chiral spin-orbital liquid as a stable phase of a realistic model for heavy-element double perovskites. This spin liquid state has Majorana fermion excitations with a gapless spectrum characterized by nodal lines along the edges of the Brillouin zone. We show that the nodal lines are topological defects of a non-Abelian Berry connection and that the system exhibits dispersing surface states. We discuss some experimental signatures of this state and compare them with properties of the spin liquid candidate Ba_2YMoO_6.Comment: 5 pages + supplementary materia

Importance of Granular Structure in the Initial Conditions for the Elliptic Flow

We show effects of granular structure of the initial conditions (IC) of hydrodynamic description of high-energy nucleus-nucleus collisions on some observables, especially on the elliptic-flow parameter v2. Such a structure enhances production of isotropically distributed high-pT particles, making v2 smaller there. Also, it reduces v2 in the forward and backward regions where the global matter density is smaller, so where such effects become more efficacious.Comment: 4 pages, 5 figure

The infall of the Virgo elliptical galaxy M60 toward M87 and the gaseous structures produced by Kelvin-Helmholtz instabilities

We present Chandra observations of hot gas structures, characteristic of gas stripping during infall, in the Virgo cluster elliptical galaxy M60 (NGC4649) located 1 Mpc east of M87. 0.5−2 keV Chandra X-ray images show a sharp leading edge in the surface brightness 12.4±0.1 kpc north and west of the galaxy center in the direction of M87 characteristic of a merger cold front due to M60's motion through the Virgo ICM. We measured a temperature of 1.00±0.02 keV for abundance 0.5Z⊙ inside the edge and 1.37+0.35−0.19 keV for abundance 0.1Z⊙ in the Virgo ICM free stream region. We find that the observed jump in surface brightness yields a density ratio of 6.44+1.04−0.67 between gas inside the edge and in the cluster free stream region. If the edge is a cold front due solely to the infall of M60 in the direction of M87, we find a pressure ratio of 4.7+1.7−1.4 and Mach number 1.7±0.3. For 1.37 keV Virgo gas we find a total infall velocity for M60 of 1030±180 kms−1. We calculate the motion in the plane of the sky to be 1012+183−192 km−1 implying an inclination angle ξ=11±3 degrees. Surface brightness profiles show the presence of a faint diffuse gaseous tail. We identify filamentary, gaseous wing structures caused by the galaxy's motion through the ICM. The structure and dimensions of these wings are consistent with simulations of Kelvin-Helmholtz instabilities as expected if the gas stripping is close to inviscid

Visualization of fetal tongue circulation using Doppler ultrasound

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154681/1/uog20393_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154681/2/uog20393.pd

Memory effects on the statistics of fragmentation

We investigate through extensive molecular dynamics simulations the fragmentation process of two-dimensional Lennard-Jones systems. After thermalization, the fragmentation is initiated by a sudden increment to the radial component of the particles' velocities. We study the effect of temperature of the thermalized system as well as the influence of the impact energy of the ``explosion'' event on the statistics of mass fragments. Our results indicate that the cumulative distribution of fragments follows the scaling ansatz $F(m)\propto m^{-\alpha}\exp{[-(m/m_0)^\gamma]}$, where $m$ is the mass, $m_0$ and $\gamma$ are cutoff parameters, and $\alpha$ is a scaling exponent that is dependent on the temperature. More precisely, we show clear evidence that there is a characteristic scaling exponent $\alpha$ for each macroscopic phase of the thermalized system, i.e., that the non-universal behavior of the fragmentation process is dictated by the state of the system before it breaks down.Comment: 5 pages, 8 figure

Spark Plug Simulation with the Use of Three Types of Fuels in Direct Injection Engines for the Evaluation of Polluting Factors

The present work has as main objective the use of a biofuel (Ecopaís) in a direct injection vehicle, it is an option to reduce damage to health and the environment, for this a static thermal simulation will be done in the spark plug, to compare the results of the aforementioned software using On Board tests, in a 1500 cc engine. The measurements of the emission factors of CO, HC and NOx gases will be considered in a route established in the city of Quito from 2399 to 2870 meters above sea level. The interaction of the element is carried out in the ANSYS Academic program which is 14977 nodes and 7523 elements to be studied with automatic meshing, obtaining that the Ecopaís and Ecopaís + Ferox fuels have the highest heat flow with a 5% divergence compared to the Extra fuel + Ferox. There is a significant reduction in pollutant emissions of 3% of CO with the use of Ecopaís in comparison to Extra + Ferox fuel, in the case of HC, Ecopaís and Ecopaís + Ferox fuels with 3% lower emissions compared to Extra fuel + Ferox, and in NOx, fuels that have Extra + Ferox and Ecopaís + Ferox solid additives are 3 and 3.5% lower compared to Ecopaís fuel, respectively. Keywords: biofuel, termal, on board, ferox, emission factors. Resumen El presente trabajo tiene como objetivo fundamental la utilización de un biocombustible (Ecopaís) en un vehículo de inyección directa, es una opción para disminuir daños a la salud y al medio ambiente, para ello se hará una simulación térmica estática en la bujía de encendido, para comparar los resultados del mencionado software mediante pruebas On Board, en un motor de 1500 cc. Las mediciones de los factores de emisión de gases de CO, HC y NOx, se contemplará en una ruta establecida en la ciudad de Quito de 2399 hasta 2870 m.s.n.m. La interacción del elemento se realiza en el programa ANSYS Academic que es de 14977 nodos y 7523 elementos a estudiar con el mallado automático, obteniendo que los combustibles Ecopaís y Ecopaís+Ferox tienen el mayor flujo de calor con una divergencia del 5% en comparación del combustible Extra + Ferox. Se evidencia una reducción significativa de emisiones contaminantes del 2.5% del CO con el uso del Ecopaís en comparación del combustible Extra + Ferox, en el caso de HC los combustibles Ecopaís y Ecopaís + Ferox con un 1% menor en emisiones en comparación al combustible Extra + Ferox, y en el NOx los combustibles que tienen aditivo sólido Extra+Ferox y Ecopaís+Ferox son menores en un 6 y 4% con respecto al combustible Ecopaís respectivamente. Palabras clave: biocombustible, térmica, on board, ferox, factores de emisiones