8,247 research outputs found
An annotated bibliography of materials suitable for use in teaching French in the elementary school
Thesis (Ed.M.)--Boston Universit
Bi-maximal mixing at GUT, the low energy data and the leptogenesis
In the framework of the minimum supersymmetric model with right-handed
neutrinos, we consider the Bi-maximal mixing which is realized at the GUT scale
and discuss a question that this model can reproduce the low energy phenomena
and the leptogenesis.Comment: Talk given by E. Takasugi at NuFact04, Osaka, Japan, July 26 - August
1,2004 - 3 pages, 4 figure
On the particle spectrum and the conformal window
We study the SU(3) gauge theory with twelve flavours of fermions in the
fundamental representation as a prototype of non-Abelian gauge theories inside
the conformal window. Guided by the pattern of underlying symmetries, chiral
and conformal, we analyze the two-point functions theoretically and on the
lattice, and determine the finite size scaling and the infinite volume fermion
mass dependence of the would-be hadron masses. We show that the spectrum in the
Coulomb phase of the system can be described in the context of a universal
scaling analysis and we provide the nonperturbative determination of the
fermion mass anomalous dimension gamma*=0.235(46) at the infrared fixed point.
We comment on the agreement with the four-loop perturbative prediction for this
quantity and we provide a unified description of all existing lattice results
for the spectrum of this system, them being in the Coulomb phase or the
asymptotically free phase. Our results corroborate the view that the fixed
point we are studying is not associated to a physical singularity along the
bare coupling line and estimates of physical observables can be attempted on
either side of the fixed point. Finally, we observe the restoration of the U(1)
axial symmetry in the two-point functions.Comment: 40 pages, 22 figure
One,Two,Zero: Scales of Strong Interactions
We discuss our results on QCD with a number of fundamental fermions ranging
from zero to sixteen. These theories exhibit a wide array of fascinating
phenomena which have been under close scrutiny, especially in recent years,
first and foremost is the approach to conformality. To keep this review
focused, we have chosen scale generation, or lack thereof as a guiding theme,
however the discussion will be set in the general framework of the analysis of
the phases and phase transitions of strong interactions at zero and nonzero
temperature.Comment: 15 pages, prepared for IJMPA Special Issue 'Recent Nonperturbative
Developments in QCD-like Theories
Chiral symmetry restoration in QCD with many flavours
We discuss the phases of QCD in the parameter space spanned by the number of
light flavours and the temperature with respect to the realisation of chiral
and conformal symmetries. The intriguing interplay of these symmetries is best
studied by means of lattice simulations, and some selected results from our
recent work are presented here.Comment: 10 pages, proceedings of the 9th International Workshop on Critical
Point and Onset of Deconfinement, 17-21 November, 2014, ZiF, Bielefeld,
German
ACA CO(J = 2–1) Mapping of the Nearest Spiral Galaxy M33. I. Initial Results and Identification of Molecular Clouds
We thank the anonymous referee for their helpful comments, which significantly improved the manuscript. This paper makes use of the following ALMA data: [ADS/JAO.ALMA#2017.1.00461.S], [ADS/JAO.ALMA#2018.A.00058.S], [ADS/JAO.ALMA#2017.1.00901.S], and [ADS/JAO.ALMA#2019.1.01182.S]. ALMA is a partnership of ESO (representing its member states), NSF (USA) and NINS (Japan), together with NRC (Canada), MOST and ASIAA (Taiwan), and KASI (Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO, and NAOJ. This work is based on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with NASA. Data analysis was in part carried out on the Multi-wavelength Data Analysis System operated by the Astronomy Data Center (ADC), National Astronomical Observatory of Japan. K.M. was supported by the ALMA Japan Research Grant of NAOJ ALMA Project, NAOJ-ALMA-289. This work was supported by NAOJ ALMA Scientific Research grant Nos. 2022-22B and JSPS KAKENHI (grant Nos. JP18H05440, JP19H05075, JP21H00049, JP21H01136, and JP21K13962).We present the results of ALMA-ACA 7 m array observations in (CO)-C-12(J = 2-1), (CO)-C-13(J = 2-1), and (CO)-O-18(J = 2-1) line emission toward the molecular-gas disk in the Local Group spiral galaxy M33 at an angular resolution of 7.& DPRIME;31 x 6.& DPRIME;50 (30 x 26 pc). We combined the ACA 7 m array (CO)-C-12(J = 2-1) data with the IRAM 30 m data to compensate for emission from diffuse molecular-gas components. The ACA+IRAM combined (CO)-C-12(J = 2-1) map clearly depicts the cloud-scale molecular-gas structure over the M33 disk. Based on the ACA+IRAM (CO)-C-12(J = 2-1) cube data, we cataloged 848 molecular clouds with a mass range from 10(3)-10(6) M (& ODOT;). We found that high-mass clouds (& GE;10(5) M (& ODOT;)) tend to associate with the 8 & mu;m bright sources in the spiral arm region, while low-mass clouds (M (& ODOT;)) tend to be apart from such 8 & mu;m bright sources and to exist in the inter-arm region. We compared the cataloged clouds with GMCs observed by the IRAM 30 m telescope at 49 pc resolution (IRAM GMC), and found that a small IRAM GMC is likely to be identified as a single molecular cloud even in ACA+IRAM CO data, while a large IRAM GMC can be resolved into multiple ACA+IRAM clouds. The velocity dispersion of a large IRAM GMC is mainly dominated by the line-of-sight velocity difference between small clouds inside the GMC rather than the internal cloud velocity broadening.ALMA:
NAOJ-ALMA-289ALMA Japan Research Grant of NAOJ ALMA Project
NAOJ-ALMA-289NAOJ ALMA Scientific Research
2022-22BMinistry of Education, Culture, Sports, Science and Technology, Japan (MEXT)
Japan Society for the Promotion of Science
Grants-in-Aid for Scientific Research (KAKENHI)
JP18H05440, JP19H05075, JP21H00049, JP21H01136, JP21K1396
Shock-Wave Heating Model for Chondrule Formation: Prevention of Isotopic Fractionation
Chondrules are considered to have much information on dust particles and
processes in the solar nebula. It is naturally expected that protoplanetary
disks observed in present star forming regions have similar dust particles and
processes, so study of chondrule formation may provide us great information on
the formation of the planetary systems.
Evaporation during chondrule melting may have resulted in depletion of
volatile elements in chondrules. However, no evidence for a large degree of
heavy-isotope enrichment has been reported in chondrules. In order to meet this
observed constraint, the rapid heating rate at temperatures below the silicate
solidus is required to suppress the isotopic fractionation.
We have developed a new shock-wave heating model taking into account the
radiative transfer of the dust thermal continuum emission and the line emission
of gas molecules and calculated the thermal history of chondrules. We have
found that optically-thin shock waves for the thermal continuum emission from
dust particles can meet the rapid heating constraint, because the dust thermal
emission does not keep the dust particles high temperature for a long time in
the pre-shock region and dust particles are abruptly heated by the gas drag
heating in the post-shock region. We have also derived the upper limit of
optical depth of the pre-shock region using the radiative diffusion
approximation, above which the rapid heating constraint is not satisfied. It is
about 1 - 10.Comment: 58 pages, including 5 tables and 15 figures, accepted for publication
in The Astrophysical Journa
Uso e ocupação das terras da metade sul do Rio Grande do Sul, Brasil.
A agricultura brasileira tem passado por um intenso processo de modernização nas últimas décadas, resultante da melhoria das tecnologias envolvidas nos sistemas de produção e das diversas políticas pública, como linhas de crédito, preços mínimos de garantia, pesquisa e extensão rural. Dentre as tecnologias, destacam-se os sistemas de informações geográficas, os quais constitui-se em uma referência importante para o planejamento territorial. Os objetivos deste estudo foram quantificar e avaliar o uso e a ocupação das terras de 35 municípios do sul do Rio Grande do Sul por meio de sistemas de informações geográficas. Instrumentais envolvendo geoprocessamento e o sensoriamento remoto foram utilizados para classificar digitalmente imagens do satélite Landsat. Elaborou-se um banco de dados geográficos com informações referentes às classes de uso e à ocupação das terras (pastagem natural e cultivada, floresta natural, reflorestamento, banhado e alagadiço, dunas e areia; lâmina d?água; agricultura/solo exposto e área urbana). Os dados foram analisados por município e integrados na forma de instrumentos públicos de gestão territorial (Conselho Regional de Desenvolvimento da Região Sul, Associação dos Municípios da Zona Sul e Bacia Hidrográfica da Lagoa Mirim). Pastagem natural/cultivada foi a classe mais expressiva, correspondendo a 50% dos valores médios dos municípios, seguida da classe de agricultura/solo exposto com 33%, reflorestamento com 5 % e florestas naturais com 4%. A análise espacial dos dados de uso e ocupação das terras possibilita a compreensão da dinâmica ocupacional e permite subsidiar a ordenação do espaço geográfico promovendo o desenvolvimento sustentável da região
Measurement of Resonant Frequency and Quality Factor of Microwave Resonators: Comparison of Methods
Precise microwave measurements of sample conductivity, dielectric, and
magnetic properties are routinely performed with cavity perturbation
measurements. These methods require the accurate determination of quality
factor and resonant frequency of microwave resonators. Seven different methods
to determine the resonant frequency and quality factor from complex
transmission coefficient data are discussed and compared to find which is most
accurate and precise when tested using identical data. We find that the
nonlinear least-squares fit to the phase vs. frequency is the most accurate and
precise when the signal-to-noise ratio is greater than 65. For noisier data,
the nonlinear least squares fit to a Lorentzian curve is more accurate and
precise. The results are general and can be applied to the analysis of many
kinds of resonant phenomena.Comment: 29 pages, 11 figure
Magnetic Domain Patterns Depending on the Sweeping Rate of Magnetic Fields
The domain patterns in a thin ferromagnetic film are investigated in both
experiments and numerical simulations. Magnetic domain patterns under a zero
field are usually observed after an external magnetic field is removed. It is
demonstrated that the characteristics of the domain patterns depend on the
decreasing rate of the external field, although it can also depend on other
factors. Our numerical simulations and experiments show the following
properties of domain patterns: a sea-island structure appears when the field
decreases rapidly from the saturating field to the zero field, while a
labyrinth structure is observed for a slowly decreasing field. The mechanism of
the dependence on the field sweeping rate is discussed in terms of the concepts
of crystallization.Comment: 4 pages, 3 figure
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