The field of self-assembled monolayers has grown rapidly since the discovery of these structures (1983) and their ability to modify physical and chemical properties of surfaces. The process of self-assembly consists of two distinct steps: (i) a fast adsorption of head group of an organic molecule on a specific substrate, and (ii) a slow organization of alkyl chains by intermolecular van der Waals interactions. These layers enable to tailor and to optimize surface properties for a variety of technological applications (chemical and biochemical sensors, biocompatibilization of metal surfaces, DNA immobilization, corrosion protection) as well as for fundamental studies of surface phenomena. In this study, the adsorption kinetics of 1-dodecanethiol on the gold substrate was studied in-situ using electrochemical impedance spectroscopy. The reason for the thiol adsorption on gold is based on two considerations: (i) gold is a relatively inert metal and does not form stable oxides on its surface, and (ii) there is a strong specific interaction with sulfur which allows the formation of a stable monolayer. Dependence of the surface coverage on the concentration was described by the Langmuir isotherm at all investigated concentrations of dodecanethiol, ranging from 3×10^(-6) to 1×10^(-3) M, in 0.1 M ethanolic solution of LiClO4. Parameters characterizing the adsorption thermodynamics, the adsorption coefficient, and the free energy of adsorption were determined. The thiol monolayers were characterized using contact angle measurements. The contact angle value (≈ 100°) has shown a high hydrophobicity. The electrochemical properties have been studied in a 0.1 M NaClO4 using cyclic voltammetry and electrochemical impedance spectroscopy. The thiol monolayer behaves as a barrier film, almost an ideal dielectric which effectively prevent electrolyte from contacting the gold substrate.

A well-known argument due to Brandon Carter suggests that intelligent life in the Galaxy is much rarer than a conventional probabilistic reasoning would suggest. A crucial assumption in that application of the anthropic reasoning is that the biological timescales for the development of life and intelligence are entirely independent (”uncorrelated”) of astrophysical timescales for habitability of planetary ecospheres around Main Sequence stars. This assumption may be too naive extrapolation from our state of relative ignorance. We discuss the impact of several plausible mechanisms inducing a correlation between the two timescales, some of them of fairly recent origin, such as the impact of local (”galactic”) gamma-ray bursts. Although the results are still far from conclusive, due mainly to our poor understanding of biogenesis and noogenesis, we hope to set up a long-term research programme aimed at addressing these uncertainties in a quantitative manner. Explosive development of astrobiology (e.g. Darling 2001) coincided with the recent resurgent interest in catastrophism in terrestrial and life sciences (e.g. Clube & Napier 1990; Clube 1995; Raup 1999). Hereby, we discuss an important link between the two: correlation introduced by catastrophes of cosmic origin between the astrophysical and biological timescales. Why is this important for an astrobiologist? There are several relevant reasons, but the one we wish to concentrate here on pertains to the role of such correlations in probabilistic arguments attempting to answer the question about the frequency of (higher forms of) life and intelligence in our Galaxy. The well-known argument due to Carter (1983), and developed by various authors (e.g. Barrow and Tipler 1986), goes as follows. If astrophysical (τ∗) and biological (τl) timescales are truly uncorrelated, life in general and intelligent life in particular forms at random epoch with respect to the characteristic timescale of its astrophysical environment (notably, the main-sequence lifetime of the considered star). In the Solar system, τ∗ ≈ τl, within the factor of two. However, in general, it should be either τl >> τ∗ or τ∗ >> τl. In the latter case, however, it is difficult to understand why the very first inhabited planetary system (that is, the Solar System) exhibits τ∗ ≈ τl behaviour, since we would then expect that life (and intelligence) arose on Earth, and probably at other places in the Solar System, much earlier than they in fact did. This gives us probabilistic reason to believe that τl >> τ∗ (in which case the anthropic

Racunalni programi za 3D modeliranje povrsinskih kopova i/ili podzemnih prostorija te planiranje proizvodnje predstavljaju temelj za upravljanje procesima i alat za projektiranje rudarskih radova. Paketi imaju siroku primjenu u određivanju svih parametara sustava povrsinske i podzemne eksploatacije tako da je moguce ucinkovito i brzo povezivanje geologije ležista, topografije terena, tehnoloskih procesa i ekonomike s pripadajucim vrlo važnim vizualnim informacijama koje prate tabicne podatke. Danas vec postoji preko tisucu profesionalnih programa koji obuhvacaju ekonomsku ocjenu povrsinskog kopa, rezerve, transportne komunikacije i sve druge tehnoloske procese, a u nastavku su navedeni samo oni koji su najistaknutiji i dostupni autoru ovog rada. Ovaj rad koncipiran je tako da se na nekoliko primjera prikažu mogucnosti 3D modeliranja, kako bi se spoznao znacaj racunalne tehnike i primijenjenih programa pri projektiranju povrsinskih kopova i podzemnih prostorija. Kao model istraživanja poslužila su ležista boksita na podrucju eksploatacijskog polja "Bespelj" kod Jajca.