Laser spectroscopy and ab initio calculations on the TAF molecule

Electronic transition spectrum of the tantalum monoflouride (TaF) molecule in the spectral region between 448 and 520 nm has been studied using the technique of laser-ablation/reaction free jet expansion and laser induced fluorescence spectroscopy. TaF molecule was produced by reacting laser-ablated tantalum atoms with sulfur hexafluoride gas seeded in argon. Sixteen vibrational bands with resolved rotational structure have been recorded and analyzed, which were organized into six electronic transition systems and the ground state has been identified to be the X$^{3}$$\Sigma$$^{-}$(0$^{+}$) state with bond length, r$_{o}$, and equilibrium vibrational frequency, $\omega$$_{e}$, determined to be 1.8209 Å and 700.1 \wn respectively. In addition, four vibrational bands belong to another transition system involving lower state with $\Omega$ = 2 component has also been analyzed. All observed transitions are with $\Delta$$\Omega$ = 0. Least-squares fit of the measured line positions yielded molecular constants for the electronic states involved. The $\Lambda$-S and $\Omega$ states of TaF were calculated at the state-averaged complete active space self-consistent field (SA-CASSCF) and the subsequent internally contracted multi-reference configuration interaction with singles and doubles and Davidson's cluster correction (MRCISD+Q) levels of theory with the active space of 4 electrons in 6 orbitals, that is, the molecular orbitals corresponding to Ta 5d6s are active. The spin-orbit coupling (SOC) is calculated by the state-interaction approach at the SA-CASSCF level via the relativistic effective core potentials (RECPs) spin-orbit operator, where the diagonal elements of the spin-orbit matrix are replaced by the above MRCISD+Q energies. The spectroscopic properties of the ground and many low-lying electronic states of the TaF molecule will be reported. With respect to the observed electronic states in this work, the calculated results are in good agreement with our experimental determinations. This work represents the first experimental investigation of the molecular structure of the TaF molecule

ELECTRONIC TRANSITIONS OF TUNGSTEN MONOSULFIDE

Electronic transition spectrum of the tungsten monosulfide (WS) molecule in the near infrared region between 725 nm and 885 nm has been recorded using laser ablation/reaction free-jet expansion and laser induced fluorescence spectroscopy. The WS molecule was produced by reacting laser - ablated tungsten atoms with 1% CS$_{2}$ seeded in argon. Fifteen vibrational bands with resolved rotational structure have been recorded and analyzed, which were organized into seven electronic transition systems. The ground state has been identified to be the X$^{3}$$Sigma$$^{-}$(0$^{+}$) state, and the determined vibrational frequency, $Delta$G$_{1/2}$ and bond length, r$_{0}$, are respectively 556.7 cm$^{-1}$ and 2.0676 AA. In addition, vibrational bands belong to another transition system involving lower state with $Omega$ = 1 component have also been analyzed. Least-squares fit of the measured line positions yielded molecular constants for the electronic states involved._x000d_ _x000d_ The low-lying $Lambda$-S states and $Omega$ sub-states of WS have been calculated using state-averaged complete active space self-consistent field (SA-CASSCF) and followed by MRCISD+Q (internally contracted multi-reference configuration interaction with singles and doubles plus Davidson’s cluster correction). The active space consists of 10 electrons in 9 orbitals corresponding to the W 5d6s and S 3p shells. The lower molecular orbitals from W 5s5p and S 3s are inactive but are also correlated, and relativistic effective core potential (RECPs) are adopted to replace the core orbitals with 60 (W) and 10 (S) core electrons, respectively. Spin-orbit coupling (SOC) is calculated via the state-interaction (SI) approach with RECP spin-orbit operators using SA-CASSCF wavefunctions, where the diagonal elements in the SOC matrix are replaced by the corresponding MRCISD+Q energies calculated above. Spectroscopic constants and potential energy curves of the ground and many low-lying $Lambda$-S states and $Omega$ sub-states of the WS molecule are obtained. The calculated spectroscopic constants of the ground and low-lying states are generally in good agreement with our experimental determination. This work represents the first experimental investigation of the electronic and molecular structure of the WS molecule._x000d

NEW ELECTRONIC STATES OF YO IN THE UV REGION

Laser excitation spectra of the yttrium monoxide (YO) molecule in the ultra violet region between the 280 and 320 nm have been recorded and studied using optical-optical double resonance (OODR) spectroscopy. The YO molecule was prepared by the reaction of laser ablated yttrium atom with oxygen under supersonic jet cooled conditions. Thirteen vibration bands have been observed via the intermediate B$^{2}$$\Sigma$$^{+}$ state from the X$^{2}$$\Sigma$$^{+}$ state. The excited states analyzed so far are generally in good case (c) coupling scheme. Besides the observation of excited $\Omega$ = 0.5 and 1.5 sub-states, and $^{2}$$\Sigma$$^{+}$ state, we have also identified and studied a forbidden transition, the [33.7]$^{4}$$\Sigma$$^{-}$ - B$^{2}$$\Sigma$$^{+}$ transition. Molecular constants for the newly observed electronic states were determined by least squares fitting the measured rotational lines. A number of low-lying $\Lambda$-S states and $\Omega$ sub-states of the YO molecule have been calculated using SA-CASSCF (state-averaged complete active space self-consistent field) followed by MS-CASPT2 (multi-state complete active space second-order perturbation theory). Since the active Y 5p shell is very important to get some low-lying electronic states with the correct principal configurations, the active space consists of 7 electrons in 12 orbitals corresponding to the Y 4d5s5p and O 2p shells. The molecular orbitals from Y 4s4p and O 2s are inactive but are also correlated, whereas the lower core-shells are relaxed only by SA-CASSCF and then kept frozen at the CASPT2 level. Spin-orbit coupling (SOC) is treated via the state-interaction (SI) approach with the one-center atomic mean field integral (AMFI) approximation for one- and two-electron spin-orbit integrals. In the SOC calculations of potential energy curves (PECs), the SA-CASSCF wavefunctions are adopted where the diagonal elements in the SOC matrix are replaced by the corresponding MS-CASPT2 energies calculated above. A comparison of the spectroscopic properties of electronic states determined experimentally and from calculations will be presented

ELECTRONIC TRANSITIONS OF YTTRIUM MONOPHOSPHIDE

Electronic transition spectrum of the yttrium monophosphide (YP) molecule in the visible region between 715 nm and 880 nm has been recorded using laser ablation/reaction free-jet expansion and laser induced fluorescence spectroscopy. The YP molecule was produced by reacting laser - ablated yttrium atoms with PH$_{3}$ seeded in argon. Thirteen vibrational bands were analyzed and five electronic transition systems have identified, namely the [12.2] $Omega$ = 3 - X$^{3} Pi_2$ transition, [13.3] $Omega$ = 3 - X$^{3} Pi_2$ transition, [13.4] $Omega$ = 3 - X$^{3} Pi_2$ transition, [13.5] $Omega$ = 3 - X$^{3} Pi_2$ transition, and [13.4] $Omega$ = 2 - X$^{3} Pi_2$ transition. Least squares fits of the measured rotational lines yielded molecular constants for the ground and excited states. The ground state symmetry and the bond length r$_0$ of the YP molecule have been determined to be a X$^{3} Pi_2$ state and 2.4413 $AA$ respectively in this work. A molecular orbital energy level diagram has been used to help the assignment of the observed electronic states. This work represents the first experimental investigation of the spectrum of the YP molecule

Effects of biofertilizer containing N-fixer, P and K solubilizers and AM fungi on maize growth: a greenhouse trial

Biofertilizer has been identified as an alternative to chemical fertilizer to increase soil fertility and crop production in sustainable farming. The objective of this greenhouse study was to evaluate the effects of four biofertilizers containing an arbuscular mycorrhizal fungus (Glomus mosseae or Glomus intraradices) with or without N-fixer (Azotobacter chroococcum), P solubilizer (Bacillus megaterium) and K solubilizer (Bacillus mucilaginous) on soil properties and the growth of Zea mays. The application treatments included control (no fertilizer), chemical fertilizer, organic fertilizer and two types of biofertilizer. The application of biofertilizer containing mycorrhizal fungus and three species of bacteria significantly increased the growth of Z. mays. The use of biofertilizer (G. mosseae and three bacterial species) resulted in the highest biomass and seedling height. This greenhouse study also indicated that half the amount of biofertilizer application had similar effects when compared with organic fertilizer or chemical fertilizer treatments. Microbial inoculum not only increased the nutritional assimilation of plant (total N, P and K), but also improved soil properties, such as organic matter content and total N in soil. The arbuscular mycorrhizal fungi (AMF) had a higher root infection rate in the presence of bacterial inoculation. By contrast, the AMF seemed to have an inhibiting effect on the P-solubilizing bacteria. The nutrient deficiency in soil resulted in a larger population of Nfixing bacteria and higher colonization of AMF

Z boson pair production at LHC in a stabilized Randall-Sundrum scenario

We study the Z boson pair production at LHC in the Randall-Sundrum scenario with the Goldberger-Wise stabilization mechanism. It is shown that comprehensive account of the Kaluza-Klein graviton and radion effects is crucial to probe the model: The KK graviton effects enhance the cross section of $g g \to Z Z$ on the whole so that the resonance peak of the radion becomes easy to detect, whereas the RS effects on the $q\bar{q} \to Z Z$ process are rather insignificant. The $p_T$ and invariant-mass distributions are presented to study the dependence of the RS model parameters. The production of longitudinally polarized Z bosons, to which the SM contributions are suppressed, is mainly due to KK gravitons and the radion, providing one of the most robust methods to signal the RS effects. The $1 \sigma$ sensitivity bounds on $(\Lambda_\pi, m_\phi)$ with $k/M_{\rm Pl} =0.1$ are also obtained such that the effective weak scale $\Lambda_\pi$ of order 5 TeV can be experimentally probed.Comment: 28 pages, LaTex file, 18 eps figure

Real Time Turbulent Video Perfecting by Image Stabilization and Super-Resolution

Image and video quality in Long Range Observation Systems (LOROS) suffer from atmospheric turbulence that causes small neighbourhoods in image frames to chaotically move in different directions and substantially hampers visual analysis of such image and video sequences. The paper presents a real-time algorithm for perfecting turbulence degraded videos by means of stabilization and resolution enhancement. The latter is achieved by exploiting the turbulent motion. The algorithm involves generation of a reference frame and estimation, for each incoming video frame, of a local image displacement map with respect to the reference frame; segmentation of the displacement map into two classes: stationary and moving objects and resolution enhancement of stationary objects, while preserving real motion. Experiments with synthetic and real-life sequences have shown that the enhanced videos, generated in real time, exhibit substantially better resolution and complete stabilization for stationary objects while retaining real motion.Comment: Submitted to The Seventh IASTED International Conference on Visualization, Imaging, and Image Processing (VIIP 2007) August, 2007 Palma de Mallorca, Spai

Refined Interfaces for Compositional Verification

The compositional verification approach of Graf & Steffen aims at avoiding state space explosion for individual processes of a concurrent system. It relies on interfaces that express the behavioural constraints imposed on each process by synchronization with the other processes, thus preventing the exploration of states and transitions that would not be reachable in the global state space. Krimm & Mounier, and Cheung & Kramer proposed two techniques to generate such interfaces automatically. In this report, we propose a refined interface generation technique that derives the interface of a process automatically from the examination of (a subset of) concurrent processes. This technique is applicable to formalisms where concurrent processes are composed either using synchronization vectors or process algebra parallel composition operators (including those of CCS, CSP, muCRL, LOTOS, and E-LOTOS). We implemented this approach in the EXP.OPEN 2.0 tool of the CADP toolbox. Several experiments indicate state space reductions by more than two orders of magnitude for the largest processes

Measurement of coagulation factors during rivaroxaban and apixaban treatment: Results from two crossover trials

Clinical epidemiolog

Human Metapneumovirus Detection in Patients with Severe Acute Respiratory Syndrome

We used a combination approach of conventional virus isolation and molecular techniques to detect human metapneumovirus (HMPV) in patients with severe acute respiratory syndrome (SARS). Of the 48 study patients, 25 (52.1%) were infected with HMPV; 6 of these 25 patients were also infected with coronavirus, and another 5 patients (10.4%) were infected with coronavirus alone. Using this combination approach, we found that human laryngeal carcinoma (HEp-2) cells were superior to rhesus monkey kidney (LLC-MK2) cells commonly used in previous studies for isolation of HMPV. These widely available HEp-2 cells should be included in conjunction with a molecular method for cell culture followup to detect HMPV, particularly in patients with SARS