852 research outputs found
Varying constants entropic--CDM cosmology
We formulate the basic framework of thermodynamical entropic force cosmology
which allows variation of the gravitational constant and the speed of light
. Three different approaches to the formulation of the field equations are
presented. Some cosmological solutions for each framework are given and one of
them is tested against combined observational data (supernovae, BAO, and CMB).
From the fit of the data it is found that the Hawking temperature numerical
coefficient is two to four orders of magnitude less than usually
assumed on the geometrical ground theoretical value of and that it is
also compatible with zero. Besides, in the entropic scenario we observationally
test that the fit of the data is allowed for the speed of light growing and
the gravitational constant diminishing during the evolution of the
universe. We also obtain a bound on the variation of to be which is at least one order of magnitude weaker than the
quasar spectra observational bound.Comment: Matched with published version. some changes in Section VII, 15 page
Experimental results of a national technical assessment procedure on commercial FRP for structural strengthening: wet-lay-up systems
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An Integrated Approach to Risk and Impacts of Geo-Resources Exploration and Exploitation
Geo-resources are widely exploited in our society, with huge benefits for both economy and communities. Nevertheless, with benefits come risks and impacts. Understanding how such risks and impacts are intrinsically borne in a given project is of critical importance for both industry and society. In particular, it is crucial to distinguish between the specific impacts related to exploiting a given energy resource and those shared with the exploitation of other energy resources. A variety of different approaches can be used to identify and assess such risks and impacts. In particular, Life Cycle Assessment (LCA) and risk assessments (RAs) are the most commonly adopted. Although both are widely used to support decision making in environmental management, they are rarely used in combination perhaps because they have been developed by largely different groups of specialists. By analyzing the structure and the ratio of the two tools, we have developed an approach for combining and harmonizing LCA and MRA; the resulting protocol envisages building MRA upon LCA both qualitatively and quantitatively. We demonstrate the approach in a case study using a virtual site (based on a real one) for geothermal energy production
Surgical management of pleomorphic adenoma of parotid gland in elderly patients: Role of morphological features.
The neoplasms of the salivary glands account for 2% of head and neck tumors and the most common form is the Pleomorphic Adenoma (PA). Parotid gland is affected from 80% to 90% of cases. In elderly this tumors occurs mostly in females. These benign tumors are composed of epithelial and myoepithelial cells that are arranged with various morphological patterns and subtypes. The classification of these tumors is also based on the amount and nature of the stroma. In literature there is a almost complete consensus that, in the major salivary glands, PAs are enclosed by a layer of fibrous tissue often called "capsule" but there is disagreement about the form, extention and thickness of this layer. The treatment is surgical and there are two main different surgical approaches: an enucleation (local dissection) or so-called subtotal superficial parotidectomy and lateral or superficial total parotidectomy. Histopathological characteristics of PAs especially of capsular alterations such as thin capsule areas, capsule-free regions, capsule penetration, satellite nodules and pseudopodia in the different subtypes are important for the choice of surgical treatment and the first explanation for tumor recurrence. In our study we describe a morphological features of 84 cases of pleomorphic adenoma of parotid gland from elderly patients treated by a surgical "enucleation like" method called nucleoresection
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