41,909 research outputs found
Reply to "Comment on `First-principles calculation of the superconducting transition in MgB2 within the anisotropic Eliashberg formalism'"
The recent preprint by Mazin et al. [cond-mat/0212417] contains many
inappropriate evaluations and/or criticisms on our published work [Phys. Rev. B
66, 020513 (2002) and Nature 418, 758 (2002)]. The preprint
[cond-mat/0212417v1] was submitted to Physical Review B as a comment on one of
our papers [Phys. Rev. B 66, 020513 (2002)]. In the reviewing process, Mazin et
al. have withdrawn many of the statements contained in cond-mat/0212417v1,
however two claims remain in their revised manuscript [cond-mat/0212417v3]: (1)
the calculated variations of the superconducting energy gap within the sigma-
or the pi-bands are not observable in real samples due to scatterings, and (2)
the Coulomb repulsion mu(k,k') is negligibly small between sigma- and pi-states
and thus should be approximated by a diagonal 2 x 2 matrix in the sigma and pi
channels. Here, we point out that the former does not affect the validity of
our theoretical work which is for the clean limit, and that the latter is not
correct
Land use survey and mapping and water resources investigation in Korea
The author has identified the following significant results. Land use imagery is applicable to land use classification for small scale land use mapping less than 1:250,000. Land use mapping by satellite is more efficient and more cost-effective than land use mapping from conventional medium altitude aerial photographs. Six categories of level 1 land use classification are recognizable from MSS imagery. A hydrogeomorphological study of the Han River basin indicates that band 7 is useful for recognizing the soil and the weathering part of bed rock. The morphological change of the main river is accurately recognized and the drainage system in the area observed is easily classified because of the more or less simple rock type. Although the direct hydrological characteristics are not obtained from the MSS imagery, the indirect information such as the permeability of the soil and the vegetation cover, is helpful in interpreting the hydrological aspects
Effect of alum (top-dressed and mixed) with rice hulls on pH and ammonia emissions from poultry houses
The use of aluminum sulfate [alum; Al2(SO3)4·14H2O] as top dressing to poultry litter has been proven in reducing ammonia (NH3) volatilization under both laboratory and field tests; however, there has been no information of alum application in mixing methods from poultry litter or rice hulls. The aim of the experiment was to evaluate the effects of alum top dressed or mixed with rice hulls as litter management methods on pH and NH3 emissions. A total of 180 broiler chickens were randomly allocated to 12 pens to a density of 0.07 m2/bird for 5 weeks, creating 4 replicates of 3 experimental treatments with 15 birds per experimental unit as a completely randomized design. The treatments included an untreated control, 100 g of alum (top dressing) and 100 g of alum (mixed)/kg of rice hull. In addition, alum treatment was usually applied by top dressing onto the rice hulls or fully mixed with the rice hulls. During the experimental period, pH and NH3 emissions were significantly reduced by the two different methods of alum amendments (P < 0.05) in the litter over time compared with the controls except for NH3 emissions at 1 through 3 weeks. However, no significant differences (P > 0.05) in pH and NH3 emission were observed between the two different methods with alum for 5 weeks. The reduction in NH3 emission from 100 g of alum top-dressed and 100 g of alum fully mixed with kg of rice hull at 5 weeks was 50 and 51%, respectively. In summary, these results indicate that âmixingâ methods of alum as well as top dressing would serve as a suitable method for decreasing NH3 emission, which resulted in lower pH.Key words: Alum, top dressing, mixing, pH, ammonia
Temperature-dependent Fermi surface evolution in heavy fermion CeIrIn5
In Cerium-based heavy electron materials, the 4f electron's magnetic moments
bind to the itinerant quasiparticles to form composite heavy quasiparticles at
low temperature. The volume of the Fermi surfacein the Brillouin zone
incorporates the moments to produce a "large FS" due to the Luttinger theorem.
When the 4f electrons are localized free moments, a "small FS" is induced since
it contains only broad bands of conduction spd electrons. We have addressed
theoretically the evolution of the heavy fermion FS as a function of
temperature, using a first principles dynamical mean-field theory (DMFT)
approach combined with density functional theory (DFT+DMFT). We focus on the
archetypical heavy electrons in CeIrIn5, which is believed to be near a quantum
critical point. Upon cooling, both the quantum oscillation frequencies and
cyclotron masses show logarithmic scaling behavior (~ ln(T_0/T)) with different
characteristic temperatures T_0 = 130 and 50 K, respectively. The resistivity
coherence peak observed at T ~ 50 K is the result of the competition between
the binding of incoherent 4f electrons to the spd conduction electrons at Fermi
level and the formation of coherent 4f electrons.Comment: 5 pages main article,3 figures for the main article, 2 page
Supplementary information, 2 figures for the Supplementary information.
Supplementary movie 1 and 2 are provided on the
webpage(http://www-ph.postech.ac.kr/~win/supple.html
Four-Dimensional Effective Supergravity and Soft Terms in M-Theory
We provide a simple macroscopic analysis of the four-dimensional effective
supergravity of the Ho\v{r}ava-Witten M-theory which is expanded in powers of
and where ,
and denote the eleven-dimensional gravitational coupling, the
Calabi-Yau volume and the eleventh length respectively. Possible higher order
terms in the K\"ahler potential are identified and matched with the heterotic
string corrections. In the context of this M-theory expansion, we analyze the
soft supersymmetry-breaking terms under the assumption that supersymmetry is
spontaneously broken by the auxiliary components of the bulk moduli
superfields. It is examined how the pattern of soft terms changes when one
moves from the weakly coupled heterotic string limit to the M-theory limit.Comment: Latex, 23 pages, 3 figures. References are added and the discussion
of the M-theory expansion parameters is enlarge
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