275 research outputs found
On the mathematical theory of living systems, I: Complexity analysis and representation
No full textThis paper is the first one of a sequel devoted to the challenging goal of developing a mathematical theory for living systems. We consider systems constituted of a number of living entities, called active particles, which have the ability to express specific strategies
and interact with other entities. The author proposes a personal path, starting from the identification of a number of common features of living systems that can be viewed as sources of complexity, focusing specifically on the representation of systems based also on a strategy to reduce their complexity. The overall system is decomposed into
functional subsystems whose representation is delivered by a probability distribution over the microscopic state of the active particles belonging to such system. Looking ahead, this paper indicates some guidelines to derive mathematical structures, where interactions
involving active particles are nonlinearly additive
Microcrystalline silicon-carbon films deposited by silane-methane mixture highly diluted in hydrogen
No full textThe Ethical and Responsibility Components in Environmental Challenges: Elements of Connection between Corporate Social Responsibility and Social Impact Assessment
No full textThe contribution constitutes a first exploratory outcome of an ongoing research by the Author on the issues of ethics and responsibility in investment processes, starting from the assumptions of the CSR approach. It makes a critical reinterpretation of it in the light of the ongoing debates and provides a specific reading key. In this sense, the contributions of other approaches and disciplines, in particular those of social investing and social impact axis, have highlighted some issues that constitute operational steps certainly at the center of future research developments and in particular linked to current environmental challenges: 1) the creation of value, 2) the stakeholders and corporate social citizenship, 3) the shared accountability, starting from the Social Report and Participatory Budget models. Specific paragraphs are dedicated to these research issues, which are intended to highlight both the impact assessment models and the technical steps yet to be explored. As a conclusion of the reasoning and to signal potential future developments, some application areas are cited (e.g. those of urban and peri-urban regeneration processes), in which the investment assessment and impact assessment models have experimented with innovation factors, linked to the aspects of the ethics and social responsibility among stakeholders
Information on gap states in a-Si(x)C(1-x):H from ESR, LESR, constant photocurrent and photothermal deflection spectroscopies
No full textDefect characterization of a-SiC:H and a-SiN:H alloys produced by ultra high vacuum plasma enhanced chemical vapor deposition in different plasma conditions
No full textHigh electronic quality a-SiC : H and a-SiN : H films with optical gap up to 2.3 eV have been deposited by ultrahigh vacuum plasma enhanced chemical vapour deposition in undiluted and hydrogen diluted reactive gas mixtures. Optical and photoelectrical characterizations have been performed. Successful progresses towards the deposition of a-SiC : H and a-SiN : H having high electronic properties and low defect densities have been obtained. Modulated photocurrent technique has been applied to study gap state energetic profiles
Integral representation and -convergence of variational integrals with -growth
No full textWe study the integral representation properties of limits of sequences of integral functionals
under nonstandard growth conditions of (p, q)-type: namely, we assume that
|z|p(x) ≤ f(x, z) ≤ L(1 + |z|p(x)) .
Under weak assumptions on the continuous function p(x), we prove Γ-convergence to integral functionals
of the same type. We also analyse the case of integrands f(x, u,Du) depending explicitly on u;
finally we weaken the assumption allowing p(x) to be discontinuous on nice sets
Evolution of structural and optical properties of nanostructured silicon carbon films deposited by plasma enhanced chemical vapour deposition
No full textNanostructured silicon carbon films composed of silicon nanocrystallites embedded in hydrogenated amorphous silicon carbon matrix have been deposited by plasma enhanced chemical vapour deposition technique using silane and methane gas mixture highly diluted in hydrogen. The structural and optical properties of the films have been investigated by X-ray diffraction, Raman, Fourier transform infrared, ultra violet-visible-near infrared and photoluminescence spectroscopies while the composition of the films has been obtained from nuclear techniques. The study has demonstrated that the structure of the films evolves from microcrystalline to nanocrystalline phase with the increase in radio frequency (rf) power. Further, it is shown that with increasing the rf power the size of silicon nanocrystallites decreases while the optical gap increases and a blueshift of visible room temperature photoluminescence peak can be observed. (c) 2012 Elsevier B.V. All rights reserved
Functional polymeric coatings for csi(Tl) scintillators
No full textThe handling of inorganic scintillators (e.g., alkali metal halides) can benefit from the availability of polymeric materials able to adhere to their surface. Polymeric materials, such as epoxy resins, can act as protective coatings, as adhesives for photodiodes to be connected with the scintillator surface, and as a matrix for functional fillers to improve the optical properties of scintillators. Here, the optical properties of two epoxy resins (E-30 by Prochima, and Technovit Epox by Heraeus Kulzer) deposited on the surface of a scintillator crystal made of CsI(Tl) were investigated, in order to improve the detection of high-energy radiation. It is found that these resins are capable of adhering to the surface of alkali metal halides. Adhesion, active at the epoxy–CsI(Tl) interface, can be explained on the basis of Coulomb forces acting between the ionic solid surface and an ionic intermediate of synthesis generated during the epoxy setting reaction. Technovit Epox showed higher transparency, and it was also functionalized by embedding white powdered pigments (PTFE or BaSO4) to achieve an optically reflective coating on the scintillator surface
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