Reactivity of hydrated hydroxide anion cluster OH(H2_{2}O)n−_{n}^{-} with H and Rb: an ab initio study

We present a theoretical investigation of the hydrated hydroxide anion clusters OH(H$_{2}$O)$_{n}^{-}$ and of the collisional complexes H-OH(H$_{2}$O)$_{n}^{-}$ and Rb-OH(H$_{2}$O)$_{n}^{-}$ (with n$=1-4$). The MP2 and CCSD(T) methods are used to calculate interaction energies, optimized geometries and vertical detachment energies. Part of the potential energy surfaces are explored with a focus on the autodetachment region. We point out the importance of diffuse functions to correctly describe the latter. We use our results to discuss the different water loss and electronic detachment channels which are the main reaction routes at room temperature. In particular, we have considered a direct and an indirect process for the electronic detachment, depending on whether water loss follows or precedes the detachment of the excess electron. We use our results to discuss the implication for astrochemistry and hybrid trap experiments in the context of cold chemistry

Cold reactive and non-reactive collisions of Li and Rb with C2−_2^-: implications for hybrid trap experiments

We present a theoretical investigation of cold reactive and non-reactive collisions of Li and Rb atoms with C$_{2}^{-}$. The potential energy surfaces for the singlet and triplet states of the Li--C$_{2}^{-}$ and Rb--C$_{2}^{-}$ systems have been obtained using the CASSCF/ic-MRCI+Q approach with extended basis sets. The potential energy surfaces are then used to investigate the associative detachment reaction and to calculate rotationally inelastic cross sections by means of the close-coupling method. The effect of the core correlation on the potential energy surfaces is discussed and we estimate the error on the collisional cross sections induced by freezing the $1s$ orbitals of the carbon atoms. The results are compared to those obtained for the Rb-OH$^{-}$ system and the applications for hybrid trap experiments are explored. Furthermore, we discuss the possibility to perform Doppler thermometry on the C$_{2}^{-}$ anion and investigate the collision process involving excited states. The implications for sympathetic cooling experiments are also discussed

Simulation of the elementary evolution operator with the motional states of an ion in an anharmonic trap

Following a recent proposal of L. Wang and D. Babikov, J. Chem. Phys. 137, 064301 (2012), we theoretically illustrate the possibility of using the motional states of a $Cd^+$ ion trapped in a slightly anharmonic potential to simulate the single-particle time-dependent Schr\"odinger equation. The simulated wave packet is discretized on a spatial grid and the grid points are mapped on the ion motional states which define the qubit network. The localization probability at each grid point is obtained from the population in the corresponding motional state. The quantum gate is the elementary evolution operator corresponding to the time-dependent Schr\"odinger equation of the simulated system. The corresponding matrix can be estimated by any numerical algorithm. The radio-frequency field able to drive this unitary transformation among the qubit states of the ion is obtained by multi-target optimal control theory. The ion is assumed to be cooled in the ground motional state and the preliminary step consists in initializing the qubits with the amplitudes of the initial simulated wave packet. The time evolution of the localization probability at the grids points is then obtained by successive applications of the gate and reading out the motional state population. The gate field is always identical for a given simulated potential, only the field preparing the initial wave packet has to be optimized for different simulations. We check the stability of the simulation against decoherence due to fluctuating electric fields in the trap electrodes by applying dissipative Lindblad dynamics.Comment: 31 pages, 8 figures. Revised version. New title, new figure and new reference

Control of molecular dynamics with zero-area fields: Application to molecular orientation and photofragmentation

The constraint of time-integrated zero-area on the laser field is a fundamental, both theoretical and experimental requirement in the control of molecular dynamics. By using techniques of local and optimal control theory, we show how to enforce this constraint on two benchmark control problems, namely molecular orientation and photofragmentation. The origin and the physical implications on the dynamics of this zero-area control field are discussed.Comment: 19 pages, 7 figure

Ab initio calculation of the 66 low lying electronic states of HeH+^+: adiabatic and diabatic representations

We present an ab initio study of the HeH$^+$ molecule. Using the quantum chemistry package MOLPRO and a large adapted basis set, we have calculated the adiabatic potential energy curves of the first 20 $^1 \Sigma^+$, 19 $^3\Sigma^+$, 12 $^1\Pi$, 9 $^3\Pi$, 4 $^1\Delta$ and 2 $^3\Delta$ electronic states of the ion in CASSCF and CI approaches. The results are compared with previous works. The radial and rotational non-adiabatic coupling matrix elements as well as the dipole moments are also calculated. The asymptotic behaviour of the potential energy curves and of the various couplings between the states is also studied. Using the radial couplings, the diabatic representation is defined and we present an example of our diabatization procedure on the $^1\Sigma^+$ states.Comment: v2. Minor text changes. 28 pages, 18 figures. accepted in J. Phys.

Knowledge management in construction

Na upravljanje z znanjem lahko gledamo kot na jasen in sistematičen način zajetja informacij in znanja nekega podjetja, njegovega razvoja, izdelkov, dela, trgovanja, strank in konkurence združenega na enem mestu, do katerega lahko dostopa ustrezno osebje, razpolaga z njim in ga koristno unovči. Gre za obširen in za vsako podjetje unikaten proces, ki predstavlja upravljanje z razumskimi sposobnostmi, zmožnostmi in spretnostmi zaposlenih v podjetju z namenom, da bi izboljšali učinkovitost podjetja in lažje obvladovali spremembe. Gradbeništvo je izredno razvejana in raznolika industrijska panoga, ki jo spremljajo številne spremembe in inovacije. Uporabljeni materiali, pogoji okolja, način gradnje, predvsem pa partnerji in izdelki se spreminjajo od projekta do projekta, po drugi strani pa lahko opazimo, da imajo gradbeni projekti tudi veliko skupnih značilnosti. Učinkovito upravljanje z znanjem v gradbenih podjetjih mora te posebnosti zaobjeti. V svetu so v zadnjih letih nastali številni modeli za upravljanje z znanjem. Z implementacijo različnih modelov si gradbeno podjetje lahko ustvari svoj sistem za zajemanje tako tihega kot eksplicitnega znanja in tako pripomore k večjemu poslovnemu uspehu ter prednosti pred konkurenco. Diplomsko delo predstavlja pomen in glavne značilnosti upravljanja z znanjem v gradbeništvu. Nadalje delo povzema nekatere izbrane modele za upravljanje z znanjem v gradbeni industriji, ki so opisani v literaturi. Analizirali smo tudi dve uspešni slovenski podjetji, pri katerih smo skušali s pomočjo izdelanega vprašalnika ter dobljenih odgovorov ugotoviti, v kolikšni meri je prisotno zavedanje pomembnosti upravljanja z znanjem in kako lahko s pomočjo le-tega njihovo poslovanje še izboljšajo. V obeh primerih se je izkazalo, da gre za sodobni podjetji, ki sledita svetovnim trendom in sta pripravljeni na tem področju graditi še naprej. Izdelek zaključujemo s predlogom obrazca o zajemu informacij iz izvedenega projekta, ki bi gradbenim podjetjem pomagal pri vgrajevanju povratnih informacij v naslednji projekt.Knowledge management could be viewed as an explicit and systematic approach to capturing information and knowledge about a company, its processes, products, services, markets, customers and competitors and then storing this in a place where relevant personnel can access, distribute it and make use of it. It is an ongoing and unique processit is management of intellectual capabilities, potentials and skills of people with the aim of improving performance and coping with change. Construction industry is an extremely complex sector accompanied by numerous changes and innovation. Materials, technologies, environmental conditions but most of all co-workers and finished products change from one project to anotheron the other hand, however, several common features can be observed in various construction projects. This has to be taken into account, if an efficient knowledge management in a construction company wants to be achieved. Several knowledge management models have been developed over the past years. A construction company needs to get acquainted with the different models in order to create its own system for acquiring both tacit and explicit knowledge, which contributes to improved business success and the company\u27s competitive edge. The thesis discusses the importance and main characteristics of knowledge management in construction. Selected knowledge management models applied to construction from the available literature are described. The analysis of two Slovenian construction companies is carried out by using a questionnaire. The obtained answers show that both companies are aware of the importance of knowledge management, and that they are willing to further develop this area. In the last part of the thesis, a draft form for data extraction is proposed that would enable the transfer of knowledge and experience from a completed project into a new one

Using a direct simulation Monte Carlo approach to model collisions in a buffer gas cell

A direct simulation Monte Carlo (DSMC) method is applied to model collisions between He buffer gas atoms and ammonia molecules within a buffer gas cell. State-tostate cross sections, calculated as a function of collision energy, enable the inelastic collisions between He and NH3 to be considered explicitly. The inclusion of rotationalstate-changing collisions affects the translational temperature of the beam, indicating that elastic and inelastic processes should not be considered in isolation. The properties of the cold molecular beam exiting the cell are examined as a function of the cell parameters and operating conditions; the rotational and translational energy distributions and are in accord with experimental measurements. The DSMC calculations show that thermalisation occurs well within the typical 10-20 mm length of many buffer gas cells, suggesting that shorter cells could be employed in many instances – yielding a higher flux of cold molecules