9,152 research outputs found
Current developments in LC-MS for pharmaceutical analysis
The current developments in liquid chromatography-mass spectrometry (LC-MS) and its applications to the analysis of pharmaceuticals are reviewed. Various mass spectrometric techniques, including electrospray and nanospray ionization, atmospheric pressure chemical ionization and photoionization and their interface with liquid chromatographic techniques are described. These include high performance liquid chromatography, capillary electrophoresis and capillary electrochromatography and the advantages and disadvantages of each technique are discussed. The applications of LC-MS to the studies of in vitro and in vivo drug metabolism, identification and characterization of impurities in pharmaceuticals, analysis of chiral impurities in drug substances and high-throughput LC-MS-MS systems for applications in the “accelerated drug discovery” process are described
A fully-integrated 1.8-V, 2.8-W, 1.9-GHz, CMOS power amplifier
This paper demonstrated the first 2-stage, 2.8W, 1.8V, 1.9GHz fully-integrated DAT power amplifier with 50Ω input and output matching using 0.18μm CMOS transistors. It has a small-signal gain of 27dB. The amplifier provides 2.8W of power into a 50Ω load with a PAE of 50%
Thick-walled composite tubes for offshore applications : an example of stress and failure analysis for filament-wound multi-layered pipes
Acknowledgements Financial support of the part of this research by The Royal Society, The Royal Academy of Engineering, and The Carnegie Trust for the Universities of Scotland is gratefully acknowledged.Peer reviewedPostprin
Assessing the Rental Value of Residential Properties: An Abductive Learning Networks Approach
This paper attempts to estimate rental value of residential properties using Abductive Learning Networks (ALN), and artificial intelligence technique. The results indicate that the ALN model provides an accurate estimation of rents with only seven input variables, while other multivariate statistical techniques do not. The ALN model automatically selects the best network structure, node types and coefficients, and therefore it simplifies the maintenance of the model. Once the final model is synthesized, the ALN model becomes very compact, rapidly executable and cost-effective.
Nematicity as a route to a magnetic field-induced spin density wave order; application to the high temperature cuprates
The electronic nematic order characterized by broken rotational symmetry has
been suggested to play an important role in the phase diagram of the high
temperature cuprates. We study the interplay between the electronic nematic
order and a spin density wave order in the presence of a magnetic field. We
show that a cooperation of the nematicity and the magnetic field induces a
finite coupling between the spin density wave and spin-triplet staggered flux
orders. As a consequence of such a coupling, the magnon gap decreases as the
magnetic field increases, and it eventually condenses beyond a critical
magnetic field leading to a field-induced spin density wave order. Both
commensurate and incommensurate orders are studied, and the experimental
implications of our findings are discussed.Comment: 5 pages, 3 figure
Analysis of nitrogen tetroxide samples Final report
Chemical analysis of nitrogen tetroxide trace impuritie
A novel route to a finite center-of-mass momentum pairing state; current driven FFLO state
The previously studied Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state is
stabilized by a magnetic field via the Zeeman coupling in spin-singlet
superconductors. Here we suggest a novel route to achieve non-zero
center-of-mass momentum pairing states in superconductors with Fermi surface
nesting. We investigate two-dimensional superconductors under a uniform
external current, which leads to a finite pair-momentum of . We
find that an FFLO state with a spontaneous pair-momentum of is
stabilized above a certain critical current which depends on the direction of
the external current. A finite arises in order to make the total
pair-momentum of perpendicular to the
nesting vector, which lowers the free energy of the FFLO state, as compared to
the superconducting and normal states. We also suggest experimental signatures
of the FFLO state.Comment: 4 pages, 5 figure
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