The Fragmented Glueball: A Personal View

A coupled-channel analysis has been performed to identify the spectrum of scalar mesons. The data include BESIII data on radiative J/ψ decays into π0π0, KS KS, ηη, and ωϕ, 15 Dalitz plots from ¯N annihilation at rest at LEAR, the CERN-Munich multipoles for ππ elastic scattering, the S-wave from BNL data on ππ scattering into KS KS, from GAMS data on ππ π0π0; ηη, and ηη', and NA48/2 data on low-mass ππ interactions from K± → ππe±v decays. The analysis reveals the existence of ten scalar isoscalar resonances. The resonances can be grouped into two classes: resonances with a large SU(3) singlet component and those with a large octet component. The production of isoscalar resonances with a large octet component should be suppressed in radiative J/ψ decays. However, in a limited mass range centered at 1900MeV, these mesons are produced abundantly. Mainly-singlet scalar resonances are produced over the full mass range but with larger intensity at 1900MeV. The total scalar isoscalar yield in radiative decays into scalar mesons shows a clear peak which is interpreted as the scalar glueball of lowest mass.

Kinetics and mechanism of catalytic oxidation of sodium ethyl mercaptide with microfluidics

Catalytic oxidation desulfurization of gasoline is a key process for the utilization of petroleum hydrocarbons. However, the inherent mechanism still remains unclear and the kinetic investigation is usually performed in processes with limited mass transfer rates. Herein, the kinetics and mechanism of catalytic oxidation of sodium ethyl mercaptide were investigated with microfluidics. On the basis of eliminating mass transfer resistance, the effects of temperature, pressure, residence time, and gas-liquid flow ratio on the oxidation were assessed. According to the results of UV-vis spectra and binding constant, it was confirmed that the catalytic center was in the form of dimer. A heterogeneous reaction kinetic model was proposed as such. The kinetic parameters close to intrinsic kinetics and corresponding kinetic rate expression were obtained.

Cooperation for Sustainable Development: a University Transport Model

The transportation system generally contributes with the largest share of Greenhouse Gases Emissions (GHG) among economic activities, which includes the high level of gas emissions from the transport system in the GHC Inventory from Higher Education Institutions (HEI). Guided by its socio-environmental agenda, the Pontifical Catholic University of Rio de Janeiro (PUC-Rio), has sought to implement integrated programs to encourage the use of alternative transportation in order to mitigate the impacts of urban mobility on the atmosphere since 2010. Free parking and shower facilities for cyclists, as well as pedestrian friendly sites and limited vehicle parking area inside the campus are some of the welcomed interventions implemented by PUC-Rio. In addition, the institution has collaborated technically with the public authorities to enable the arrival of good quality mass transportation to the University neighborhood. Even facing limited mass public transportation in the surroundings of the main campus, PUC-Rio has implemented a series of transportation initiatives that rely on the commitment and partnership of its community (students, professors and staff), who strongly support new solutions for sustainable development and contribute to the improvement of PUC-Rio transportation performance

Oxidation and Microstructural Behaviors of Ni-Based Alloys Strengthened by (Ta, Hf)C Carbides at 1250 °C in Air

Two alloys based on nickel and designed to be reinforced by MC carbides thanks to the presence of Hf and Ta were produced by casting. They were subjected to 50 h-long isothermal exposure at 1250 °C in synthetic air with thermogravimetric monitoring of the oxidation progress. In the as-cast state, they contain both significant quantities of (Hf,Ta)C carbides. Their verified melting start temperatures, close to 1300 °C, allowed performing the planned oxidation test. The two alloys demonstrated a chromia-forming behavior with limited mass gain rates. However, they also showed a rather low resistance to oxide spallation at cooling, which is in proportion with the Ta/Hf ratio. After 50 h at 1250 °C, the morphology of the carbides had significantly evolved, from their initial script-like shape to a fragmented and coalesced state. The results are promising, but the use of these alloys at 1250 °C needs further improvements on the mechanical level.

Scalable Electrode Materials with Nanoporous Current Collector Shells for Supercapacitors with Ultrahigh Areal and Volumetric Capacitances

Supercapacitor is characterized by its high power density, but the bottleneck is the limited mass loading and low specific capacitance of active materials in a single electrode. Although there have...

Application of magnetic field to CO hydrogenation using a confined-space catalyst: effect on reactant gas diffusivity and reactivity

Synergy between an external magnetic field and limited mass transfer within zeolite cavities leads to different diffusion abilities of CO and H2 during the reaction within the catalyst pores, leading to significant improvement in CO conversion.

Comparison of historical and recent accumulation rates on Abramov Glacier, Pamir Alay

Glaciers located in western High Mountain Asia (HMA) have shown mass gain or limited mass losses compared to other mountain regions since ~2000. Increases in accumulation may be responsible. Although no contemporary measurements exist to explore this hypothesis, extensive historic measurements including firn density, stratigraphy and accumulation rates at ~4400 m a.s.l. on Abramov Glacier, Pamir Alay, provide valuable indications of accumulation changes. Abramov Glacier is located at the northern margin of western HMA. In this study, we assess unique historical firn data of Abramov Glacier from the 1970s to evaluate past firn conditions in this data sparse region. The current firn state is investigated based on a series of in situ measurements including firn cores and ground-penetrating radar measurements performed in 2018. We compare the legacy data with contemporary firn characteristics. Our results indicate a high year-to-year variability, but generally increasing net accumulation during the last 60 years on Abramov Glacier, with 0.84 ± 0.22 m w.e. for 2011–18 compared to 0.68 ± 0.32 m w.e. for 1965–72 and 0.59 ± 0.22 m w.e. for 1970–97. These results from in situ data provide ground truth for the data-sparse western HMA.

How the breakout-limited mass in B-star centrifugal magnetospheres controls their circumstellar H α emission

ABSTRACT Strongly magnetic B-type stars with moderately rapid rotation form ‘centrifugal magnetospheres’ (CMs) from the magnetic trapping of stellar wind material in a region above the Kepler co-rotation radius. A long-standing question is whether the eventual loss of such trapped material occurs from gradual drift and/or diffusive leakage, or through sporadic ‘centrifugal breakout’ (CBO) events, wherein magnetic tension can no longer contain the built-up mass. We argue here that recent empirical results for Balmer-α emission from such B-star CMs strongly favour the CBO mechanism. Most notably, the fact that the onset of such emission depends mainly on the field strength at the Kepler radius, and is largely independent of the stellar luminosity, strongly disfavours any drift/diffusion process, for which the net mass balance would depend on the luminosity-dependent wind feeding rate. In contrast, we show that in a CBO model, the maximum confined mass in the magnetosphere is independent of this wind feeding rate and has a dependence on field strength and Kepler radius that naturally explains the empirical scalings for the onset of H α emission, its associated equivalent width, and even its line profile shapes. However, the general lack of observed Balmer emission in late-B and A-type stars could still be attributed to a residual level of diffusive or drift leakage that does not allow their much weaker winds to fill their CMs to the breakout level needed for such emission; alternatively, this might result from a transition to a metal–ion wind that lacks the requisite hydrogen.