Opacity data for HCN and HNC from a new ab initio line list

A new extensive ab initio rotation-vibration HCN/HNC line list is presented. The line list contains rotation-vibration energy levels, line frequencies, and line strengths for transitions between states with energy less than 18,000 cm-1 and with J≤60. This line list greatly improves the quality and range of HCN/HNC data available. It is presently the most extensive and most accurate ab initio HCN/HNC line list in existence. It is hoped that this data set will be used in models of C star atmospheres and elsewhere

Ab initio rotation–vibration spectra of HCN and HNC

We have calculated an ab initio HCN/HNC linelist for all transitions up to J=25 and 18 000 cm−1 above the zero point energy. This linelist contains more than 200 million lines each with frequencies and transition dipoles. The linelist has been calculated using our semi-global HCN/HNC VQZANO+PES and dipole moment surface, which were reported in van Mourik et al. (J. Chem. Phys. 115 (2001) 3706). With this linelist we synthesise absorption spectra of HCN and HNC at 298 K and we present the band centre and band transition dipoles for the bands which are major features in these spectra. Several of the HCN bands and many of the HNC bands have not been previously studied. Our line intensities reproduce via fully ab initio methods the unusual intensity structure of the HCN CN stretch fundamental (0001) for the first time and also the forbidden (0220) HCN bending overtone. We also compare the J=1→0 pure rotational transition dipole in the HCN/HNC ground and vibrationally excited states with experimental and existing ab initio results

High Transverse Momentum Results from the STAR Collaboration

The STAR collaboration presents new measurements of high p_T hadron production in Au+Au and p+p collisions at RHIC. We extend the previously reported suppression of inclusive hadron and large azimuthal anisotropies to much higher transverse momentum, decisively establishing the existence of strong medium effects on hadron production well into the perturbative regime. Near-angle two-particle correlations show directly that hadrons at pT > 4 GeV/c result from the fragmentation of jets. Additional evidence for the onset of perturbative QCD in this region comes from the flavor dependence of the inclusive yields and elliptic flow. Finally, comparison of back-to-back hadron pairs at high pT in p+p and in Au+Au collisions at various centralities reveals a striking suppression of high pT back-to-back pairs in the most central Au+Au collisions. All of these phenomena suggest a picture in which partons or their hadronic fragments are strongly absorbed in the bulk matter, with the observed hadrons resulting from jets produced on the periphery of the collision zone and directed outwards.Comment: Plenary talk at QM2002 in Nantes/France, to be published in the conference proceedings (Nuc.Phys.), 10 page

Analysis of travelling waves associated with the modelling of aerosolised skin grafts

A previous model developed by the authors investigates the growth patterns of keratinocyte cell colonies after they have been applied to a burn site using a spray technique. In this paper, we investigate a simplified one-dimensional version of the model. This model yields travelling wave solutions and we analyse the behaviour of the travelling waves. Approximations for the rate of healing and maximum values for both the active healing and the healed cell densities are obtained

Characterization, quantification, and replication of human sinus bone for surgery simulation phantoms

The requirement for artificial but realistic, tactile, anatomical models for surgical practice in medical simulation is increasingly evident and shows potential for greater efficiency and availability, and lower costs. Anatomically correct, detailed models with the physical surgical characteristics of real tissue, combined with the ability to reproduce one-off cases, would provide an invaluable tool in the development of surgery. This research work investigates the capture of geometrical and physical data from the human sinus to subsequently direct the production and optimization of such simulation phantoms. Micro-computed tomography analysis of the entire sinus was performed to characterize the sinus complex geometry. Following an extensive review, specialized mechanical testing apparatus and methods relevant to the surgical methods employed were designed and produced. This provided comparative analysis methods for both biological and artificial phantom materials and allowed the optimization of phantom materials with respect to the derived target values

DVR3D: a program suite for the calculation of rotation–vibration spectra of triatomic molecules

The DVR3D program suite calculates energy levels, wavefunctions, and where appropriate dipole transition moments, for rotating and vibrating triatomic molecules. Potential energy and, where necessary, dipole surfaces must be provided. Expectation values of geometrically defined functions can be calculated, a feature which is particularly useful for fitting potential energy surfaces. The programs use an exact (within the Born–Oppenheimer approximation) Hamiltonian and offer a choice of Jacobi or Radau internal coordinates and several body-fixed axes. Rotationally excited states are treated using an efficient two-step algorithm. The programs uses a Discrete Variable Representation (DVR) based on Gauss–Jacobi and Gauss–Laguerre quadrature for all 3 internal coordinates and thus yields a fully point-wise representation of the wavefunctions. The vibrational step uses successive diagonalisation and truncation which is implemented for a number of possible coordinate orderings. The rotational, expectation value and transition dipole programs exploit the savings offered by performing integrals on a DVR grid. The new version has been rewritten in FORTRAN 90 to exploit the dynamic array allocations and the algorithm for dipole and spectra calculations have been substantially improved. New modules allow the z-axis to be embedded perpendicular to the plane of the molecule and for the calculation of expectation values

Associated Top Quark-Higgs Boson Production at the LHC

We compute the O(alpha_s^3) inclusive cross section for the process pp -> t-tbar-h in the Standard Model, at sqrt(s)=14 TeV. The next-to-leading order corrections drastically reduce the renormalization and factorization scale dependence of the Born cross section and increase the total cross section for renormalization and factorization scales larger than m_t. These corrections have important implications for models of new physics involving the top quark.Comment: 5 pages, 4 figures, RevTeX

Silicon Pad Detectors for the PHOBOS Experiment at RHIC

The PHOBOS experiment is well positioned to obtain crucial information about relativistic heavy ion collisions at RHIC, combining a multiplicity counter with a multi-particle spectrometer. The multiplicity arrays will measure the charged particle multiplicity over the full solid angle. The spectrometer will be able to identify particles at mid-rapidity. The experiment is constructed almost exclusively of silicon pad detectors. Detectors of nine different types are configured in the multiplicity and vertex detector (22,000 channels) and two multi-particle spectrometers (120,000 channels). The overall layout of the experiment, testing of the silicon sensors and the performance of the detectors during the engineering run at RHIC in 1999 are discussed.Comment: 7 pages, 7 figures, 1 table, Late

Mitochondrial function and oxygen supply in normal and in chronically ischemic muscle: A combined 31P magnetic resonance spectroscopy and near infrared spectroscopy study in vivo

AbstractPurpose: We used 31P magnetic resonance spectroscopy (MRS) and near-infrared spectroscopy (NIRS) as a means of quantifying abnormalities in calf muscle oxygenation and adenosine triphosphate (ATP) turnover in peripheral vascular disease (PVD). Methods: Eleven male patients with PVD (mean age, 65 years; range, 55-76 years) and nine male control subjects of similar age were observed in a case-control study in vascular outpatients. Inclusion criteria were more than 6 months' calf claudication (median, 1.5 years; range, 0.6-18 years); proven femoropopliteal or iliofemoral occlusive or stenotic disease; maximum treadmill walking distance (2 km/h, 10° gradient) of 50 to 230 m (mean, 112 m); ankle-brachial pressure index of 0.8 or less during exercise (mean, 0.47; range, 0.29-0.60). Exclusion criteria included diabetes mellitus, anemia, and magnet contraindications. Simultaneous 31P MRS and NIRS of lateral gastrocnemius was conducted during 2 to 4 minutes of voluntary 0.5 Hz isometric plantarflexion at 50% and 75% maximum voluntary contraction force (MVC), followed by 5 minutes recovery. Each subject was studied three times, and the results were combined. Results: Compared with control subjects, patients with PVD showed (1) normal muscle cross-sectional area, MVC, ATP turnover, and contractile efficiency (ATP turnover per force/area); (2) larger phosphocreatine (PCr) changes during exercise (ie, increased shortfall of oxidative ATP synthesis) and slower PCr recovery (47% ± 7% [mean ± SEM] decrease in functional capacity for oxidative ATP synthesis, P =.001); (3) faster deoxygenation during exercise and slower postexercise reoxygenation (59% ± 7% decrease in rate constant, P =.0009), despite reduced oxidative ATP synthesis; (4) correlation between PCr and NIRS recovery rate constants (P <.02); and (5) correlations between smaller walking distance, slower PCr recovery, and reduced MVC (P <.001). The precision of the key measurements (rate constants and contractile efficiency) was 12% to 18% interstudy and 30% to 40% intersubject. Conclusion: The primary lesion in oxygen supply dominates muscle metabolism. Reduced force-generation in patients who are affected more may protect muscle from metabolic stress. (J Vasc Surg 2001;34:1103-10.