Persistent Monitoring by Multiple Unmanned Aerial Vehicles Using Bernstein Polynomials

Journal of Optimization Theory and Applications - A framework for monitoring a target modeled as Dubins car using multiple UAVs is proposed. The UAVs are subject to minimum and maximum speed,...     

What Makes a Thing What It Is? Aristotle and Hegel on Identity

The notion of identity is investigated through Aristotle and Hegel as supporters of two different ontological conceptions: pluralism of substances and relational holism. Through Aristotle, I examine both the thesis according to which the identity of an object is constituted by its properties and the difficulties which this thesis encounters (e.g., those raised by Max Black). Aristotle easily defines the identity in species, in genus, and in number; some problems arise regarding the identity of individuals: for these, it is not enough to indicate the definition and the proper qualities, but matter is needed. Matter cannot, however, be a criterion for identifying duplicate objects: in this case, it plays at most the role of a “weak individuator.” A weak individuator involves relations with other entities. The use of relations in determining the identity of an entity is extensively treated by Hegel, according to whom, in order to define the identity of an object a multiplicity of particular objects is required and, therefore, relations among entities. I conclude by proposing a notion of the object understood not as an independent, separate, and autonomous item, but as a portion of the world, which is given in a phenomenological context and identifies a dialectical context.     

The electronic structure of carbonyl metal clusters : I. An INDO investigation of mono-, di- and trinuclear nickel complexes

A series of mono-, di- and trinuclear nickel carbonyl complexes has been investigated by means of the MO-LCAO method. The total molecular energies, one-electron energies and electron distributions have been computed and their variations along the series are discussed. The wavefunction of the complex has been considered in terms of contributions of the individual MO's of the free CO molecule in order to compute the variations of the σ-donor and π-accepting ability of the carbonyl ligand.     

Influence of temperature on microdomain organization of mixed cationic-zwitterionic lipidic monolayers at the air-water interface

The thermodynamic behavior of mixed DOTAP-DPPC monolayers at the air-water interface has been investigated in the temperature range from 15 to 45 degrees C, covering the temperature interval where the thermotropic phase transition of DPPC, from solid-like to liquid-like, takes place. Based on the regular solution theory, the miscibility of the two lipids in the mixed monolayer was evaluated in terms of the excess Gibbs free energy of mixing DeltaG(ex), activity coefficients f(1) and f(2) and interaction parameter omega between the two lipids. The mixed DOTAP-DPPC film was found to have positive deviations from ideality at low DOTAP mole fractions, indicating a phase-separated binary mixture. This effect depends on the temperature and is largely conditioned by the structural chain conformation of the DPPC lipid monolayer. The thermodynamic parameters associated to the stability and the miscibility of these two lipids in a monolayer structure have been discussed in the light of the phase diagram of the DOTAP-DPPC aqueous mixtures obtained from differential scanning calorimetry measurements. The correlation between the temperature behavior of DOTAP-DPPC monolayers and their bulk aqueous mixtures has been briefly discussed.     

Valence-only model potential calculations on copper hydride molecule

Different sets of one-electron functions obtained according to the strong-orthogonal geminal theory (GEM) [1], the Generalized Molecular Orbital (GMO) method [2] and the exchange maximization between virtual and occupied orbitals (EVO) [3], are tested as basis for CI calculations. The efficiency of the three procedures is discussed investigating the electronic structure of the CuH molecule using an effective-core potential. The values computed for the bond length, the dissociation energy and the vibrational frequency of the ground electronic state are compared with the experimental ones. The charge distribution is examined to estimate the contribution of the d electrons to the Cu-H bond. Comparisons are made with the results obtained by other theoretical works in which the copper atom is treated as a one valence electron atom.