A5075996334- Molecular spectroscopy and chirality
- Advanced NMR Techniques and Applications
- Parallel Computing and Optimization Techniques
- Molecular Spectroscopy and Structure
- Distributed and Parallel Computing Systems
- Liquid Crystal Research Advancements
- Advanced Chemical Physics Studies
- Numerical methods in engineering
- Advanced Data Storage Technologies
- Electromagnetic Simulation and Numerical Methods
- Atomic and Subatomic Physics Research
- Quantum, superfluid, helium dynamics
- Spectroscopy and Quantum Chemical Studies
- Analytical Chemistry and Chromatography
- NMR spectroscopy and applications
- Electron Spin Resonance Studies
- Geotechnical Engineering and Underground Structures
- Various Chemistry Research Topics
- Computational Physics and Python Applications
- Cloud Computing and Resource Management
- Photochemistry and Electron Transfer Studies
- Gamma-ray bursts and supernovae
- Chemical Thermodynamics and Molecular Structure
- Advanced Numerical Methods in Computational Mathematics
- Nonlinear Dynamics and Pattern Formation
Louisiana State University
2018-2024
Los Alamos National Laboratory
2019-2024
Ruhr University Bochum
2023-2024
Sandia National Laboratories
2024
Polytechnique Montréal
2018-2024
Oak Ridge National Laboratory
2023
University of Oregon
2022
Universitat Politècnica de Catalunya
2022
Barcelona Supercomputing Center
2022
Fujitsu (Japan)
2022
To achieve scalability with today's heterogeneous HPC resources, we need a dramatic shift in our thinking; MPI+X is not enough. Asynchronous Many Task (AMT) runtime systems break down the global barriers imposed by Bulk Synchronous Programming model. HPX an open-source, C++ Standards compliant AMT system that developed diverse international community of collaborators called The Ste||ar Group. provides features which allow application developers to naturally use key design patterns, such as...
The N.M.R. spectrum of o-chlorotoluene, dissolved in the nematic phase 4-methoxybenzylidene-4-amino-α-methylcinnamic acid n-propylester is analysed and shape proton skeleton determined. position lowest energy potential barrier to methyl rotation found be that which chlorine atom staggered group, height order 5·0 kJ mol-1 (1200 cal/mole).
Measurements of 17O-NMR-chemical shifts (relative to H2O) have been carried out in a variety 125 compounds which 115 are organic. 1 The resonance singly bonded oxygen is shifted low field by all substituents except CH3. effects atoms directly increases the order H, C, S, Cl < N O. Double bonds OCX (X 0) give rise considerable shifts, whereas groups C affect only slightly. 2 In carbonyl doubly high acetaldehyde) substituents. effect heteroatoms decreases > O F Br. Conjugation does not...
Substitution effects in proton magnetic resonance spectra of meta‐ and paradisubstituted benzene are shown to be additive at low concentration hexane. The absolute values the measured meta‐disubstituted benzene. separated by substitution thus obtained used predict chemical shifts. In orthodisubstituted polysubstituted as well with mesomeric interaction new found discussed. Correlations Hammett‐parameters given. An electrostatic theory is a good approximation long contribution shifts low.
The N.M.R. spectrum of pyridine oriented in the nematic phase anisole-azophenyl-n-capronate has been studied. analysis carried out iteratively using a modified version computer programme LAOCOONII (re-named as LAOCOONOR). details modification are discussed. direct couplings shown to be negative sign. Ratios various inter-proton distances determined irrespective orientation molecule. They agree within experimental error with microwave results.
The new challenges presented by exascale system architectures have resulted in difficulty achieving the desired scalability using traditional distributed-memory runtimes.Asynchronous many-task systems (AMT) are based on a paradigm showing promise addressing these challenges, providing application developers with productive and performant approach to programming next generation systems.HPX is C++ Library for concurrency parallelism that developed STE||AR Group, an international group of...
Abstract The variation of the position high resolution proton magnetic resonance lines a polar solute with dielectric constant solvent may be calculated on assumption that dipole polarizes surrounding medium, setting up an electrostatic 'reaction field' which alters distribution electrons responsible for shielding. theory predicts shape molecule should important in determining magnitude this reaction field. shielding values measured range solutions acetonitrile, representing rod-like...
Summary The formation of Casparian strips (CS) and the deposition suberin at endodermis plant roots are thought to limit apoplastic transport water ions. We investigated specific role each these barriers in control hydro‐mineral by consequences on shoot growth. A collection Arabidopsis thaliana mutants defective and/or CS development was characterized under standard conditions using a hydroponic system Phenopsis platform. Mutants altered had enhanced root hydraulic conductivity, indicating...
Abstract In order to be detectable, the volume concentration of chemically equivalent deuterons has exceed a certain minimum limit. As this decreases with increasing molecular volume, deuteron NMR. at natural abundance is limited small molecules and therefore no practical importance. (At density 1 weight less than 20 per deuteron.)In fully deuterated samples signal‐to‐noise ratio same magnitude as for protons, because loss in sensitivity can compensated by an increased sample.
Abstract Peridigm is a meshfree peridynamics code written in C++ for use on large-scale parallel computers. It was originally developed at Sandia National Laboratories and currently managed as an open-source, community driven software project. Its primary features include bond-based, state-based, non-ordinary state-based constitutive models, bond failure laws, contact, support explicit implicit time integration. To date, has been used primarily by methods developers focused solid mechanics...
N.M.R. spectroscopy of partially oriented molecules provides a convenient technique for obtaining detailed information about molecular properties. However, the resulting data is sometimes internally inconsistent and markedly dependent on conditions experiment, throwing some doubt general precision method. The probable reason this correlation between vibrational reorientational motion which neglected in conventional analysis. In paper theory effects spectral parameters elaborated. relation...
Abstract In consequence of recent advances made mainly in ab initio methods, relatively accurate anharmonic force fields are beginning to be available for an increasing number molecules. This makes the calculation vibrational averaging effects on various molecular properties practical. present paper this is discussed detail, pointing out simplifications which result when anharmonicity specified by conversion between equilibrium and average geometries molecule. The different contributions...
Abstract 17 O‐NMR spectra of benzofurazan oxide at room temperature show two resonance lines. This adds evidence to support the N‐oxide structure be correct. The O are dependent on temperature, due an equilibration. average lifetime tautomers is order 10 −4 s + 45°C. activation energy equilibrium found 17,2 ± 1,5 kcal/mole and frequency factor 3 · 14 16 −1 .
The theoretical scheme described in Part I for the analysis of nuclear resonance spectra type ABX q is extended to systems AB2X where symmetry such that there only one BX coupling constant. It shown these can be interpreted a systematic manner all q. allow determination relative signs three constants and therefore used compare couplings between nuclei different species (AX BX) with same (AB). Further which could studied by similar methods are indicated briefly.
Ranging from NVIDIA GPUs to AMD and Intel GPUs: Given the heterogeneity of available accelerator cards within current supercomputers, portability is a key aspect for modern HPC applications. In Octo-Tiger, we rely on Kokkos its various execution spaces portable compute kernels. turn, use HPX coordinate kernel launches, CPU tasks, communication. This combination allows us have fine interleaving between CPU/GPU computations communication, enabling scalability supercomputers. However, work...