546 research outputs found
Recommended from our members
Regional economic impacts of changes in electricity rates resulting from Western Area Power Administration`s power marketing alternatives
This technical memorandum describes an analysis of regional economic impacts resulting from changes in retail electricity rates due to six power marketing programs proposed by Western Area Power Administration (Western). Regional economic impacts of changes in rates are estimated in terms of five key regional economic variables: population, gross regional product, disposable income, employment, and household income. The REMI (Regional Impact Models, Inc.) and IMPLAN (Impact Analysis for Planning) models simulate economic impacts in nine subregions in the area in which Western power is sold for the years 1993, 2000, and 2008. Estimates show that impacts on aggregate economic activity in any of the subregions or years would be minimal for three reasons. First, the utilities that buy power from Western sell only a relatively small proportion of the total electricity sold in any of the subregions. Second, reliance of Western customers on Western power is fairly low in each subregion. Finally, electricity is not a significant input cost for any industry or for households in any subregion
A Crystal Structure of the Bifunctional Antibiotic Simocyclinone D8, Bound to DNA Gyrase
Simocyclinones are bifunctional antibiotics that inhibit bacterial DNA gyrase by preventing DNA binding to the enzyme. We report the crystal structure of the complex formed between the N-terminal domain of the Escherichia coli gyrase A subunit and simocyclinone D8, revealing two binding pockets that separately accommodate the aminocoumarin and polyketide moieties of the antibiotic. These are close to, but distinct from, the quinolone-binding site, consistent with our observations that several mutations in this region confer resistance to both agents. Biochemical studies show that the individual moieties of simocyclinone D8 are comparatively weak inhibitors of gyrase relative to the parent compound, but their combination generates a more potent inhibitor. Our results should facilitate the design of drug molecules that target these unexploited binding pockets
Nonlinear magnetic susceptibility and aging phenomena in reentrant ferromagnet: CuCoCl-FeCl graphite bi-intercalation compound
Linear and nonlinear dynamic properties of a reentrant ferromagnet
CuCoCl-FeCl graphite bi-intercalation compound are
studied using AC and DC magnetic susceptibility. This compound undergoes
successive phase transitions at the transition temperatures (= 16 K),
(= 9.7 K), and (= 3.5 K). The static and dynamic behaviors of
the reentrant spin glass phase below are characterized by those of
normal spin glass phase with critical exponent = 0.57 0.10, a
dynamic critical exponent = 8.5 1.8, and an exponent (= 1.55
0.13) for the de Almeida -Thouless line. A prominent nonlinear
susceptibility is observed between and and around ,
suggesting a chaotic nature of the ferromagnetic phase () and the helical spin ordered phase (). The
aging phenomena are observed both in the RSG and FM phases, with the same
qualitative features as in normal spin glasses. The aging of zero-field cooled
magnetization indicates a drastic change of relaxation mechanism below and
above . The time dependence of the absorption
is described by a power law form () in the
ferromagnetic phase, where at =
0.05 Hz and = 7 K. No -scaling law for
[] is observed.Comment: 14 pages, 16 figures, and 2 table
Choice of tracers for the evaluation of spray deposits
Tracer substances, used to evaluate spraying effectiveness, ordinarily modify the surface tension of aqueous solutions. This study aimed to establish a method of using tracers to evaluate distribution and amount of spray deposits, adjusted to the surface tension of the spraying solution. The following products were tested: 0.15% Brilliant Blue, 0.15% Saturn Yellow in 0.015% Vixilperse lignosulfonate, and 0.005% sodium fluorescein, and mixtures of Brilliant Blue plus Saturn Yellow and Brilliant Blue plus sodium fluorescein at the same concentrations. Solutions were deposited on citrus leaves and stability was determined by measuring fluorescence and optical density of solutions without drying, dried in the dark and exposed to sunlight for 2, 4 and 8 h. These values were compared to those obtained directly in water. The static surface tension of the tracer solution was determined by weighing droplets formed during a period of 20 to 40 seconds. The Brilliant Blue and Saturn Yellow mixture at 0.15% was stable under all conditions tested. It was not absorbed by the leaves and maintained the same surface tension as that of water, thus permitting concentration adjustment to the same levels used for agrochemical products, and allowing the development of a qualitative method based on visual evaluation of the distribution of the pigment under ultraviolet light and of a quantitative method based on the determination of the amount of the dye deposited in the same solution. Spray deposition could be evaluated at different surface tensions of the spraying solution, simulating the effect of agrochemical formulations
Production and Decay of D_1(2420)^0 and D_2^*(2460)^0
We have investigated and final states and
observed the two established charmed mesons, the with mass
MeV/c and width MeV/c and
the with mass MeV/c and width
MeV/c. Properties of these final states, including
their decay angular distributions and spin-parity assignments, have been
studied. We identify these two mesons as the doublet predicted
by HQET. We also obtain constraints on {\footnotesize } as a function of the cosine of the relative phase of the two
amplitudes in the decay.Comment: 15 pages in REVTEX format. hardcopies with figures can be obtained by
sending mail to: [email protected]
Measurement of the branching fraction for
We have studied the leptonic decay of the resonance into tau
pairs using the CLEO II detector. A clean sample of tau pair events is
identified via events containing two charged particles where exactly one of the
particles is an identified electron. We find . The result is consistent with
expectations from lepton universality.Comment: 9 pages, RevTeX, two Postscript figures available upon request, CLNS
94/1297, CLEO 94-20 (submitted to Physics Letters B
Observation of a Narrow Resonance of Mass 2.46 GeV/c^2 Decaying to D_s^*+ pi^0 and Confirmation of the D_sJ^* (2317) State
Using 13.5 inverse fb of e+e- annihilation data collected with the CLEO II
detector we have observed a narrow resonance in the Ds*+pi0 final state, with a
mass near 2.46 GeV. The search for such a state was motivated by the recent
discovery by the BaBar Collaboration of a narrow state at 2.32 GeV, the
DsJ*(2317)+ that decays to Ds+pi0. Reconstructing the Ds+pi0 and Ds*+pi0 final
states in CLEO data, we observe peaks in both of the corresponding
reconstructed mass difference distributions, dM(Dspi0)=M(Dspi0)-M(Ds) and
dM(Ds*pi0)=M(Ds*pi0)-M(Ds*), both of them at values near 350 MeV. We interpret
these peaks as signatures of two distinct states, the DsJ*(2317)+ plus a new
state, designated as the DsJ(2463)+. Because of the similar dM values, each of
these states represents a source of background for the other if photons are
lost, ignored or added. A quantitative accounting of these reflections confirms
that both states exist. We have measured the mean mass differences
= 350.0 +/- 1.2 [stat] +/- 1.0 [syst] MeV for the DsJ*(2317) state, and
= 351.2 +/- 1.7 [stat] +/- 1.0 [syst] MeV for the new DsJ(2463)+
state. We have also searched, but find no evidence, for decays of the two
states via the channels Ds*+gamma, Ds+gamma, and Ds+pi+pi-. The observations of
the two states at 2.32 and 2.46 GeV, in the Ds+pi0 and Ds*+pi0 decay channels
respectively, are consistent with their interpretations as (c anti-strange)
mesons with orbital angular momentum L=1, and spin-parities of 0+ and 1+.Comment: 16 pages postscript, also available through
http://w4.lns.cornell.edu/public/CLNS, version to be published in Physical
Review D; minor modifications and fixes to typographical errors, plus an
added section on production properties. The main results are unchanged; they
supersede those reported in hep-ex/030501
Measurement of the Charge Asymmetry in
We report on a search for a CP-violating asymmetry in the charmless hadronic
decay B -> K*(892)+- pi-+, using 9.12 fb^-1 of integrated luminosity produced
at \sqrt{s}=10.58 GeV and collected with the CLEO detector. We find A_{CP}(B ->
K*(892)+- pi-+) = 0.26+0.33-0.34(stat.)+0.10-0.08(syst.), giving an allowed
interval of [-0.31,0.78] at the 90% confidence level.Comment: 7 pages postscript, also available through
http://w4.lns.cornell.edu/public/CLNS, submitted to PR
Study of the q^2-Dependence of B --> pi ell nu and B --> rho(omega)ell nu Decay and Extraction of |V_ub|
We report on determinations of |Vub| resulting from studies of the branching
fraction and q^2 distributions in exclusive semileptonic B decays that proceed
via the b->u transition. Our data set consists of the 9.7x10^6 BBbar meson
pairs collected at the Y(4S) resonance with the CLEO II detector. We measure
B(B0 -> pi- l+ nu) = (1.33 +- 0.18 +- 0.11 +- 0.01 +- 0.07)x10^{-4} and B(B0 ->
rho- l+ nu) = (2.17 +- 0.34 +0.47/-0.54 +- 0.41 +- 0.01)x10^{-4}, where the
errors are statistical, experimental systematic, systematic due to residual
form-factor uncertainties in the signal, and systematic due to residual
form-factor uncertainties in the cross-feed modes, respectively. We also find
B(B+ -> eta l+ nu) = (0.84 +- 0.31 +- 0.16 +- 0.09)x10^{-4}, consistent with
what is expected from the B -> pi l nu mode and quark model symmetries. We
extract |Vub| using Light-Cone Sum Rules (LCSR) for 0<= q^2<16 GeV^2 and
Lattice QCD (LQCD) for 16 GeV^2 <= q^2 < q^2_max. Combining both intervals
yields |Vub| = (3.24 +- 0.22 +- 0.13 +0.55/-0.39 +- 0.09)x10^{-3}$ for pi l nu,
and |Vub| = (3.00 +- 0.21 +0.29/-0.35 +0.49/-0.38 +-0.28)x10^{-3} for rho l nu,
where the errors are statistical, experimental systematic, theoretical, and
signal form-factor shape, respectively. Our combined value from both decay
modes is |Vub| = (3.17 +- 0.17 +0.16/-0.17 +0.53/-0.39 +-0.03)x10^{-3}.Comment: 45 pages postscript, also available through
http://w4.lns.cornell.edu/public/CLNS, submitted to PR
Study of the B^0 Semileptonic Decay Spectrum at the Upsilon(4S) Resonance
We have made a first measurement of the lepton momentum spectrum in a sample
of events enriched in neutral B's through a partial reconstruction of B0 -->
D*- l+ nu. This spectrum, measured with 2.38 fb**-1 of data collected at the
Upsilon(4S) resonance by the CLEO II detector, is compared directly to the
inclusive lepton spectrum from all Upsilon(4S) events in the same data set.
These two spectra are consistent with having the same shape above 1.5 GeV/c.
From the two spectra and two other CLEO measurements, we obtain the B0 and B+
semileptonic branching fractions, b0 and b+, their ratio, and the production
ratio f+-/f00 of B+ and B0 pairs at the Upsilon(4S). We report b+/b0=0.950
(+0.117-0.080) +- 0.091, b0 = (10.78 +- 0.60 +- 0.69)%, and b+ = (10.25 +- 0.57
+- 0.65)%. b+/b0 is equivalent to the ratio of charged to neutral B lifetimes,
tau+/tau0.Comment: 14 page, postscript file also available at
http://w4.lns.cornell.edu/public/CLN
- …