2,744 research outputs found
Couplings between a collection of BF models and a set of three-form gauge fields
Consistent interactions that can be added to a free, Abelian gauge theory
comprising a collection of BF models and a set of three-form gauge fields are
constructed from the deformation of the solution to the master equation based
on specific cohomological techniques. Under the hypotheses of smooth, local, PT
invariant, Lorentz covariant, and Poincare invariant interactions, supplemented
with the requirement on the preservation of the number of derivatives on each
field with respect to the free theory, we obtain that the deformation procedure
modifies the Lagrangian action, the gauge transformations as well as the
accompanying algebra.Comment: 17 page
Theoretical and applicative dimensions regarding communication management
The paper represents the synthesis approach on a scientific investigation made in a private company having 37 employees, aiming at establishing the relation between the management processes and communication management, and for this purpose, following the presentation of some introductory notions, theoretical and practical objectives have been formulated, as well as two research hypotheses. The methods and techniques applied during the research, along with the targeted group have been also briefly presented. In the end, there is a presentation of the outputs of the research and the conclusions stemming from the verification of the hypotheses, on this occasion the main drawbacks of the managerial processes being identified. It was therefore established that the managerial processes map must be redesigned for the company's performance improvement, by redesigning a new communication management scheme that would consider the afore-mentioned findings. The correspondent elements of the formal communication organization do not determine similar configurations on the informal plan due to systemic and integrated operation of the communication management. The importance of this practical approach stems from the fact that the consequences of the organization and communication coordination in the managerial processes are proved.Getting an insight into these plans can only be beneficial for the development of communication management and for the growth of the organizational performancemanagement, communication management, organizational performance
Principles and applications of CVD powder technology
Chemical vapor deposition (CVD) is an important technique for surface modification of powders through either grafting or deposition of films and coatings. The efficiency of this complex process primarily depends on appropriate contact between the reactive gas phase and the solid particles to be treated. Based on this requirement, the first part of this review focuses on the ways to ensure such contact and particularly on the formation of fluidized beds. Combination of constraints due to both fluidization and chemical vapor deposition leads to the definition of different types of reactors as an alternative to classical fluidized beds, such as spouted beds, circulating beds operating in turbulent and fast-transport regimes or vibro-fluidized beds. They operate under thermal but also plasma activation of the reactive gas and their design mainly depends on the type of powders to be treated. Modeling of both reactors and operating conditions is a valuable tool for understanding and optimizing these complex processes and materials. In the second part of the review, the state of the art on materials produced by fluidized bed chemical vapor deposition is presented. Beyond pioneering applications in the nuclear power industry, application domains, such as heterogeneous catalysis, microelectronics, photovoltaics and protection against wear, oxidation and heat are potentially concerned by processes involving chemical vapor deposition on powders. Moreover, simple and reduced cost FBCVD processes where the material to coat is immersed in the FB, allow the production of coatings for metals with different wear, oxidation and corrosion resistance. Finally, large-scale production of advanced nanomaterials is a promising area for the future extension and development of this technique
Embryonic and post-embryonic utilization and subcellular localization of the nuclear receptor SpSHR2 in the sea urchin
SpSHR2 (Strongylocentrotus purpuratus steroid hormone receptor 2) is a nuclear receptor, encoded by a maternal RNA in the sea urchin embryo. These maternal SpSHR2 transcripts, which are present in all cells, persist until the blastula stage and then are rapidly turned over. A small fraction of the embryonic SpSHR2 protein is maternal, but the majority of this nuclear receptor in the embryo is the product of new synthesis, presumably from the maternal RNA after fertilization. In agreement with the mRNA distribution, the SpSHR2 protein is also detected in all embryonic cells. Contrary to the RNA though, the SpSHR2 protein persists throughout embryonic development to the pluteus stage, long after the mRNA is depleted. Following fertilization and as soon as the 2-cell stage, the cytoplasmic SpSHR2 protein enters rapidly into the embryonic nuclei where it appears in the form of speckles. During subsequent stages (from fourth cleavage onward), SpSHR2 resides in speckled form in both the nucleus and the cytoplasm of the embryonic cells. The cytoplasmic localization of SpSHR2 differs between polarized and non-polarized cells, maintaining an apical position in the ectoderm and endoderm versus a uniform distribution in mesenchyme cells. Following the end of embryonic development (pluteus stage), the SpSHR2 protein is depleted from all tissues. During the ensuing four weeks of larval development, the SpSHR2 is not detected in either the larval or the rudiment cells which will give rise to the adult. Just prior to metamorphosis, at about 35 days post-fertilization, the protein is detected again but in contrast to the uniform distribution in the early embryo, the larval SpSHR2 is specifically expressed in cells of the mouth epithelium and the epaulettes. In adult ovaries and testes, SpSHR2 is specifically detected in the myoepithelial cells surrounding the ovarioles and the testicular acini. Nuclear SpSHR2 in blastula extracts binds to the C1R hormone response element in the upstream promoter region of the CyIIIb actin gene indicating that the latter may be a target of this nuclear receptor in the sea urchin embryo
Blow-up and global existence for a general class of nonlocal nonlinear coupled wave equations
We study the initial-value problem for a general class of nonlinear nonlocal
coupled wave equations. The problem involves convolution operators with kernel
functions whose Fourier transforms are nonnegative. Some well-known examples of
nonlinear wave equations, such as coupled Boussinesq-type equations arising in
elasticity and in quasi-continuum approximation of dense lattices, follow from
the present model for suitable choices of the kernel functions. We establish
local existence and sufficient conditions for finite time blow-up and as well
as global existence of solutions of the problem.Comment: 11 pages. Minor changes and added reference
Note on Global Regularity for 2D Oldroyd-B Fluids with Diffusive Stress
We prove global regularity of solutions of Oldroyd-B equations in 2 spatial
dimensions with spatial diffusion of the polymeric stresses
Experimental demonstration of sub-wavelength image channeling using capacitively loaded wire medium
In this letter we experimentally demonstrate a possibility to achieve
significant sub-wavelength resolution of a near-field image channeled through a
layer of an electromagnetic crystal. An image having radius of has
been realized using an electrically dense lattice of capacitively loaded wires.
The loading allows to reduce the lattice period dramatically so that it is only
a small fraction of the free-space wavelength. It is shown that losses in the
structure only decrease the total amplitude of the image, but do not influence
the resolution.Comment: 4 pages, 7 figures, submitted to PR
Universal integral quadratic forms over dyadic local fields
A quadratic form over a non-archimedian local field of characteristic zero
is called universal if it is integral and it represents all non-zero
integers of . Xu Fei and Zhang Yang determined all universal quadratic forms
in the case when is non-dyadic. In the more complicated dyadic case, when
is a finite extension of , they solved the same problem only
in the ternary case. In our paper we solve this problem in the general case.
Our result is given in terms of BONGs (bases of norm generators) but at the end
of the paper we translate our result in terms of the more traditional Jordan
splittings
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