6,235 research outputs found
PURDU-WINCOF: A computer code for establishing the performance of a fan-compressor unit with water ingestion
A model for predicting the performance of a multi-spool axial-flow compressor with a fan during operation with water ingestion was developed incorporating several two-phase fluid flow effects as follows: (1) ingestion of water, (2) droplet interaction with blades and resulting changes in blade characteristics, (3) redistribution of water and water vapor due to centrifugal action, (4) heat and mass transfer processes, and (5) droplet size adjustment due to mass transfer and mechanical stability considerations. A computer program, called the PURDU-WINCOF code, was generated based on the model utilizing a one-dimensional formulation. An illustrative case serves to show the manner in which the code can be utilized and the nature of the results obtained
Ipteks Peraturan Pemerintah No.71 Tahun 2010 Tentang Akuntansi Pemerintahan Berbasis Akrual pada Badan Penanggulangan Bencana Daerah Provinsi Sulawesi Utara
Organization of Prov. Regional Disaster Management Agency North Sulawesi Moves in the Field of Disaster Management Operations Centers which need to implement Government Regulation No. 71 of 2010 on accrual bases to provide information from financial records and facilitate more effective performance. In accounting there are two records of the first cash basis and accrual basis. Accrual Basis is the basis for facilitating performance measurement, in regulating clearer and more understandable. This study uses descriptive research methods that aim to explain the circumstances, events or everything related to programs that can be explained in words or numbers. The application of Government Regulation No. 71 of 2010 concerning accrual basis is certainly in accordance with what has been implemented by the Law that has been implemented by the government, Government Accounting Standards, Financial Accounting Standards. Accrual basis application needs financial statements, so that problems can be found or what things are not in accordance with the activities of either budgeting or calculation of budgeting
From vocational training to education: the development of a no-frontiers education policy for Europe?
This article focuses on developments towards an EU educational policy. Education was not included as one of the Community competencies in the Treaty of Rome. The first half of the article analyses the way that the European Court of Justice and the Commission of the European Communities between them managed to develop a series of substantial Community programmes out of Article 128 on vocational training. The second half of the article discusses educational developments in the community following the Treaty on European Union and the Treaty of Amsterdam. Whilst the legal competence of the community now includes education, the author's argument is that the inclusion of an educational competence will not result in further developments to mirror those in the years before the Treaty on Europe</p
High frequency dynamics in a monatomic glass
The high frequency dynamics of glassy Selenium has been studied by Inelastic
X-ray Scattering at beamline BL35XU (SPring-8). The high quality of the data
allows one to pinpoint the existence of a dispersing acoustic mode for
wavevectors () of nm, helping to clarify a previous
contradiction between experimental and numerical results. The sound velocity
shows a positive dispersion, exceeding the hydrodynamic value by 10%
at nm. The dependence of the sound attenuation
, reported for other glasses, is found to be the low- limit of a
more general law which applies also to the
higher region, where no longer holds.Comment: Phys. Rev. Lett. (Accepted
The influence of the Lande -factor in the classical general relativistic description of atomic and subatomic systems
We study the electromagnetic and gravitational fields of the proton and
electron in terms of the Einstenian gravity via the introduction of an
arbitrary Lande -factor in the Kerr-Newman solution. We show that at length
scales of the order of the reduced Compton wavelength, corrections from
different values of the -factor are not negligible and discuss the presence
of general relativistic effects in highly ionized heavy atoms. On the other
hand, since at the Compton-wavelength scale the gravitational field becomes
spin dominated rather than mass dominated, we also point out the necessity of
including angular momentum as a source of corrections to Newtonian gravity in
the quantum description of gravity at this scale.Comment: 11 pages, 2 figure
Weakly frustrated two-dimensional Heisenberg antiferromagnets: thermodynamic properties from a non-perturbative approach
We analyze the thermodynamic properties of the spin-S two-dimensional quantum
Heisenberg antiferromagnet on a square lattice with nearest and next-nearest
neighbor couplings in the Neel phase (J_2/J_1<0.4) employing the quantum
hierarchical reference theory (QHRT), a non-perturbative implementation of the
renormalization group method to quantum systems. We investigate the staggered
susceptibility, the structure factors and the correlation length at finite
temperature and for different values of the frustration ratio. From the finite
temperature results, we also extrapolate ground state properties, such as spin
stiffness and spontaneous staggered magnetization, providing an estimate of the
extent of quantum corrections. The behavior of these quantities as a function
of frustration may provide some hint on the breakdown of the Neel phase at zero
temperature for larger values of J_2
A gauge invariant study of the monopole condensation in non Abelian lattice gauge theories
We investigate the Abelian monopole condensation in finite temperature SU(2)
and SU(3) pure lattice gauge theories. To this end we introduce a gauge
invariant disorder parameter built up in terms of the lattice Schr\"odinger
functional. Our numerical results show that the disorder parameter is different
from zero and Abelian monopole condense in the confined phase. On the other
hand our numerical data suggest that the disorder parameter tends to zero, in
the thermodynamic limit, when the gauge coupling constant approaches the
critical deconfinement value. In the case of SU(3) we also compare the
different kinds of Abelian monopoles which can be defined according to the
choice of the Abelian subgroups.Comment: 18 pages, 7 figures, LaTe
The Effective Field Theory of Inflation
We study the effective field theory of inflation, i.e. the most general
theory describing the fluctuations around a quasi de Sitter background, in the
case of single field models. The scalar mode can be eaten by the metric by
going to unitary gauge. In this gauge, the most general theory is built with
the lowest dimension operators invariant under spatial diffeomorphisms, like
g^{00} and K_{mu nu}, the extrinsic curvature of constant time surfaces. This
approach allows us to characterize all the possible high energy corrections to
simple slow-roll inflation, whose sizes are constrained by experiments. Also,
it describes in a common language all single field models, including those with
a small speed of sound and Ghost Inflation, and it makes explicit the
implications of having a quasi de Sitter background. The non-linear realization
of time diffeomorphisms forces correlation among different observables, like a
reduced speed of sound and an enhanced level of non-Gaussianity.Comment: 26 pages. v2: minor corrections, JHEP published versio
Intersecting Flavor Branes
We consider an instance of the AdS/CFT duality where the bulk theory contains
an open string tachyon, and study the instability from the viewpoint of the
boundary field theory. We focus on the specific example of the AdS_5 X S^5
background with two probe D7 branes intersecting at general angles. For generic
angles supersymmetry is completely broken and there is an open string tachyon
between the branes. The field theory action for this system is obtained by
coupling to N =4 super Yang-Mills two N =2 hyper multiplets in the fundamental
representation of the SU(N) gauge group, but with different choices of
embedding of the two N=2 subalgebras into N=4. On the field theory side we find
a one-loop Coleman-Weinberg instability in the effective potential for the
fundamental scalars. We identify a mesonic operator as the dual of the open
string tachyon. By AdS/CFT, we predict the tachyon mass for small 't Hooft
coupling (large bulk curvature) and confirm that it violates the AdS stability
bound.Comment: 36 page
Cosmological Non-Linearities as an Effective Fluid
The universe is smooth on large scales but very inhomogeneous on small
scales. Why is the spacetime on large scales modeled to a good approximation by
the Friedmann equations? Are we sure that small-scale non-linearities do not
induce a large backreaction? Related to this, what is the effective theory that
describes the universe on large scales? In this paper we make progress in
addressing these questions. We show that the effective theory for the
long-wavelength universe behaves as a viscous fluid coupled to gravity:
integrating out short-wavelength perturbations renormalizes the homogeneous
background and introduces dissipative dynamics into the evolution of
long-wavelength perturbations. The effective fluid has small perturbations and
is characterized by a few parameters like an equation of state, a sound speed
and a viscosity parameter. These parameters can be matched to numerical
simulations or fitted from observations. We find that the backreaction of
small-scale non-linearities is very small, being suppressed by the large
hierarchy between the scale of non-linearities and the horizon scale. The
effective pressure of the fluid is always positive and much too small to
significantly affect the background evolution. Moreover, we prove that
virialized scales decouple completely from the large-scale dynamics, at all
orders in the post-Newtonian expansion. We propose that our effective theory be
used to formulate a well-defined and controlled alternative to conventional
perturbation theory, and we discuss possible observational applications.
Finally, our way of reformulating results in second-order perturbation theory
in terms of a long-wavelength effective fluid provides the opportunity to
understand non-linear effects in a simple and physically intuitive way.Comment: 84 pages, 3 figure
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