1,968 research outputs found
Ultrahigh Surface Area Three-Dimensional Porous Graphitic Carbon from Conjugated Polymeric Molecular Framework
Porous graphitic carbon is essential for many applications such as energy storage devices, catalysts, and sorbents. However, current graphitic carbons are limited by low conductivity, low surface area, and ineffective pore structure. Here we report a scalable synthesis of porous graphitic carbons using a conjugated polymeric molecular framework as precursor. The multivalent cross-linker and rigid conjugated framework help to maintain micro- and mesoporous structures, while promoting graphitization during carbonization and chemical activation. The above unique design results in a class of highly graphitic carbons at temperature as low as 800 ??C with record-high surface area (4073 m2 g-1), large pore volume (2.26 cm-3), and hierarchical pore architecture. Such carbons simultaneously exhibit electrical conductivity >3 times more than activated carbons, very high electrochemical activity at high mass loading, and high stability, as demonstrated by supercapacitors and lithium-sulfur batteries with excellent performance. Moreover, the synthesis can be readily tuned to make a broad range of graphitic carbons with desired structures and compositions for many applications.clos
Nanoparticle Tracking Analysis for the Enumeration and Characterization of Mineralo-Organic Nanoparticles in Feline Urine
Urinary stone disease, particularly calcium oxalate, is common in both humans
and cats. Calcifying nanoparticles (CNP) are spherical nanocrystallite
material, and are composed of proteins (fetuin, albumin) and inorganic
minerals. CNP are suggested to play a role in a wide array of pathologic
mineralization syndromes including urolithiasis. We documented the development
of a clinically relevant protocol to assess urinary CNP in 9 healthy cats
consuming the same diet in a controlled environment using Nanoparticle
Tracking Analysis (NTA®). NTA® is a novel method that allows for
characterization of the CNP in an efficient, accurate method that can
differentiate these particles from other urinary submicron particulates. The
predominant nanoscale particles in feline urine are characteristic of CNP in
terms of their size, their ability to spontaneously form under suitable
conditions, and the presence of an outer layer that is rich in calcium and
capable of binding to hydroxyapatite binders such as alendronate and
osteopontin. The expansion of this particle population can be suppressed by
the addition of citrate to urine samples. Further, compounds targeting
exosomal surfaces do not label these particulates. As CNP have been associated
with a number of significant urologic maladies, the method described herein
may prove to be a useful adjunct in evaluating lithogenesis risk in mammals
Relativistic Calculation of two-Electron one-Photon and Hypersatellite Transition Energies for Elements
Energies of two-electron one-photon transitions from initial double K-hole
states were computed using the Dirac-Fock model. The transition energies of
competing processes, the K hypersatellites, were also computed. The
results are compared to experiment and to other theoretical calculations.Comment: accepted versio
Assurance of Distributed Algorithms and Systems: Runtime Checking of Safety and Liveness
This paper presents a general framework and methods for complete programming
and checking of distributed algorithms at a high-level, as in pseudocode
languages, but precisely specified and directly executable, as in formal
specification languages and practical programming languages, respectively. The
checking framework, as well as the writing of distributed algorithms and
specification of their safety and liveness properties, use DistAlgo, a
high-level language for distributed algorithms. We give a complete executable
specification of the checking framework, with a complete example algorithm and
example safety and liveness properties.Comment: Small fixes to improve property specifications, including
improvements not in the RV 2020 final versio
The protease‐activated receptor 4 Ala120Thr variant alters platelet responsiveness to low‐dose thrombin and protease‐activated receptor 4 desensitization, and is blocked by non‐competitive P2Y12 inhibition
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146616/1/jth14318_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146616/2/jth14318.pd
The influence of transition metal solutes on dislocation core structure and values of Peierls stress and barrier in tungsten
Several transition metals were examined to evaluate their potential for
improving the ductility of tungsten. The dislocation core structure and Peierls
stress and barrier of screw dislocations in binary
tungsten-transition metal alloys (WTM) were investigated using
first principles electronic structure calculations. The periodic quadrupole
approach was applied to model the structure of dislocation. Alloying
with transition metals was modeled using the virtual crystal approximation and
the applicability of this approach was assessed by calculating the equilibrium
lattice parameter and elastic constants of the tungsten alloys. Reasonable
agreement was obtained with experimental data and with results obtained from
the conventional supercell approach. Increasing the concentration of a
transition metal from the VIIIA group, i.e. the elements in columns headed by
Fe, Co and Ni, leads to reduction of the elastic constant and
increase of elastic anisotropy A=. Alloying W with a group
VIIIA transition metal changes the structure of the dislocation core from
symmetric to asymmetric, similar to results obtained for WRe
alloys in the earlier work of Romaner {\it et al} (Phys. Rev. Lett. 104, 195503
(2010))\comments{\cite{WRECORE}}. In addition to a change in the core symmetry,
the values of the Peierls stress and barrier are reduced. The latter effect
could lead to increased ductility in a tungsten-based
alloy\comments{\cite{WRECORE}}. Our results demonstrate that alloying with any
of the transition metals from the VIIIA group should have similar effect as
alloying with Re.Comment: 12 pages, 8 figures, 3 table
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