Reply to the comment on 'Validity of certain soft photon amplitudes'

We respond to the accompanying Comment on our paper, 'Validity of certain soft photon amplitudes'. While we hope the discussion here clarifies the issues, we have found nothing which leads to a change in the original conclusions of our paper.Comment: 6 pages, Latex, uses ReVTeX, now publishe

Comment on ``Validity of certain soft-photon amplitudes''

The criteria suggested by Welsh and Fearing (nucl-th/9606040) to judge the validity of certain soft-photon amplitudes are examined. We comment on aspects of their analysis which lead to incorrect conclusions about published amplitudes and point out important criteria which were omitted from their analysis.Comment: 6 pages plus 1 postscript figure, Revte

A 0.8 V T Network-Based 2.6 GHz Downconverter RFIC

A 2.6 GHz downconverter RFIC is designed and implemented using a 0.18 μm CMOS standard process. An important goal of the design is to achieve the high linearity that is required in WiMAX systems with a low supply voltage. A passive T phase-shift network is used as an RF input stage in a Gilbert cell to reduce supply voltage. A single supply voltage of 0.8 V is used with a power consumption of 5.87 mW. The T network-based downconverter achieves a conversion gain (CG) of 5 dB, a single-sideband noise figure (NF) of 16.16 dB, an RF-to-IF isolation of greater than 20 dB, and an input-referred third-order intercept point (IIP3) of 1 dBm when the LO power of -13 dBm is applied

Anatomy of the Soft-Photon Approximation in Hadron-Hadron Bremsstrahlung

A modified Low procedure for constructing soft-photon amplitudes has been used to derive two general soft-photon amplitudes, a two-s-two-t special amplitude $M^{TsTts}_{\mu}$ and a two-u-two-t special amplitude $M^{TuTts}_{\mu}$, where s, t and u are the Mandelstam variables. $M^{TsTts}_{\mu}$ depends only on the elastic T-matrix evaluated at four sets of (s,t) fixed by the requirement that the amplitude be free of derivatives ($\partial$T/$\partial$s and /or $\partial$T/$\partial t$). Likewise $M^{TuTts}_{\mu}$ depends only on the elastic T-matrix evaluated at four sets of (u,t). In deriving these amplitudes, we impose the condition that $M^{TsTts}_{\mu}$ and $M^{TuTts}_{\mu}$ reduce to $\bar{M}^{TsTts}_{\mu}$ and $\bar{M}^{TuTts}_{\mu}$, respectively, their tree level approximations. The amplitude $\bar{M}^{TsTts}_{\mu}$ represents photon emission from a sum of one-particle t-channel exchange diagrams and one-particle s-channel exchange diagrams, while the amplitude $\bar{M}^{TuTts} _{\mu}$ represents photon emission from a sum of one-particle t-channel exchange diagrams and one-particle u-channel exchange diagrams. The precise expressions for $\bar{M}^{TsTts}_{\mu}$ and $\bar{M}^{TuTts}_{\mu}$ are determined by using the radiation decomposition identities of Brodsky and Brown. We point out that it is theoretically impossible to describe all bremsstrahlung processes by using only a single class of soft-photon amplitudes. At least two different classes are required: the amplitudes which depend on s and t or the amplitudes which depend on u and t. When resonance effects are important, the amplitude $M^{TsTts}_{\mu}$, not $M^{Low(st)}_{\mu}$, should be used. For processes with strong u-channel exchange effects, the amplitude $M^{TuTts}_{\mu}$ should be the first choice.Comment: 49 pages report # LA-UR-92-270

Nonstoichiometric doping and Bi antisite defect in single crystal Bi2Se3

We studied the defects of Bi2Se3 generated from Bridgman growth of stoichiometric and nonstoichiometric self-fluxes. Growth habit, lattice size, and transport properties are strongly affected by the types of defect generated. Major defect types of Bi_Se antisite and partial Bi_2-layer intercalation are identified through combined studies of direct atomic-scale imaging with scanning transmission electron microscopy (STEM) in conjunction with energy-dispersive X-ray spectroscopy (STEM-EDX), X-ray diffraction, and Hall effect measurements. We propose a consistent explanation to the origin of defect type, growth morphology, and transport property.Comment: 5 pages, 5 figure

Modes of Growth in Dynamic Systems

Regardless of a system's complexity or scale, its growth can be considered to be a spontaneous thermodynamic response to a local convergence of down-gradient material flows. Here it is shown how growth can be constrained to a few distinct modes that depend on the availability of material and energetic resources. These modes include a law of diminishing returns, logistic behavior and, if resources are expanding very rapidly, super-exponential growth. For a case where a system has a resolved sink as well as a source, growth and decay can be characterized in terms of a slightly modified form of the predator-prey equations commonly employed in ecology, where the perturbation formulation of these equations is equivalent to a damped simple harmonic oscillator. Thus, the framework presented here suggests a common theoretical under-pinning for emergent behaviors in the physical and life sciences. Specific examples are described for phenomena as seemingly dissimilar as the development of rain and the evolution of fish stocks.Comment: 16 pages, 6 figures, including appendi

Development and Pilot of a Checklist for Management of Acute Liver Failure in the Intensive Care Unit

Introduction Acute liver failure (ALF) is an ideal condition for use of a checklist. Our aims were to develop a checklist for the management of ALF in the intensive care unit (ICU) and assess the usability of the checklist among multiple providers. Methods The initial checklist was developed from published guidelines and expert opinion. The checklist underwent pilot testing at 11 academic liver transplant centers in the US and Canada. An anonymous, written survey was used to assess the usability and quality of the checklist. Written comments were used to improve the checklist following the pilot testing period. Results We received 81 surveys involving the management of 116 patients during the pilot testing period. The overall quality of the checklist was judged to be above average to excellent by 94% of users. On a 5-point Likert scale, the majority of survey respondents agreed or agreed strongly with the following checklist characteristics: the checklist was easy to read (99% agreed/agreed strongly), easy to use (97%), items are categorized logically (98%), time to complete the checklist did not interfere with delivery of appropriate and safe patient care (94%) and was not excessively burdensome (92%), the checklist allowed the user the freedom to use his or her clinical judgment (80%), it is a useful tool in the management of acute liver failure (98%). Web-based and mobile apps were developed for use of the checklist at the point of care. Conclusion The checklist for the management of ALF in the ICU was shown in this pilot study to be easy to use, helpful and accepted by a wide variety of practitioners at multiple sites in the US and Canada

Using Multiple Signatures to Improve Accuracy of Substorm Identification

We have developed a new procedure for combining lists of substorm onset times from multiple sources. We apply this procedure to observational data and to magnetohydrodynamic (MHD) model output from 1–31 January 2005. We show that this procedure is capable of rejecting false positive identifications and filling data gaps that appear in individual lists. The resulting combined onset lists produce a waiting time distribution that is comparable to previously published results, and superposed epoch analyses of the solar wind driving conditions and magnetospheric response during the resulting onset times are also comparable to previous results. Comparison of the substorm onset list from the MHD model to that obtained from observational data reveals that the MHD model reproduces many of the characteristic features of the observed substorms, in terms of solar wind driving, magnetospheric response, and waiting time distribution. Heidke skill scores show that the MHD model has statistically significant skill in predicting substorm onset times.Plain Language SummaryMagnetospheric substorms are a process of explosive energy release from the plasma environment on the nightside of the Earth. We have developed a procedure to identify substorms that uses multiple forms of observational data in combination. Our procedure produces a list of onset times for substorms, where each onset time has been independently confirmed by two or more observational data sets. We also apply our procedure to output from a physical model of the plasma environment surrounding the Earth and show that this model can predict a significant fraction of the substorm onset times.Key PointsCombining substorm onsets from multiple types of observations can produce a more accurate list of onset times than any single listThe resulting onset list exhibits expected behavior for substorms in terms of magnetospheric driving and responseSWMF has a weak but consistent and statistically significant skill in predicting substormsPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154913/1/jgra55605_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154913/2/jgra55605-sup-0002-2019JA027559-Text_SI-S01.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154913/3/jgra55605.pd

Dilepton Production in Nucleon-Nucleon Reactions With and Without Hadronic Inelasticities

We calculate elementary proton-proton and neutron-proton bremsstrahlung and their contribution to the $e^+e^-$ invariant mass distribution. At 4.9 GeV, the proton-proton contribution is larger than neutron-proton, but it is small compared to recent data. We then make a first calculation of bremsstrahlung in nucleon-nucleon reactions with multi-hadron final states. Again at 4.9 GeV, the many-body bremsstrahlung is larger than simple nucleon-nucleon bremsstrahlung by more than an order of magnitude in the low-mass region. When the bremsstrahlung contributions are summed with Dalitz decay of the $\eta$, radiative decay of the $\Delta$ and from two-pion annihilation, the result matches recent high statistics proton-proton data from the Dilepton Spectrometer collaboration.Comment: 1+17 pages plus 11 PostScript figures uuencoded and appended, McGill/93-9, TPI-MINN-93/18-