29 research outputs found
Synthesis, crystal structure and biological activity of copper(II) complex with 4-nitro-3-pyrazolecarboxylic ligand
The reaction of 4-nitro-3-pyrazolecarboxylic acid and Cu(OAc)2⋅H2O in ethanol resulted in a new coordination compound [Cu2(4-nitro-3- -pzc)2(H2O)6]2H2O (4nitro-3pzc = 4-nitro-3-pyrazolecarboxylate). The compound was investigated by means of single-crystal X-ray diffraction and infrared spectroscopy. The biological activity of the complex was also tested. In the crystal structure of [Cu2(4nitro-3-pzc)2(H2O)6]2H2O, the Cu(II) ion is in a distorted [4+2] octahedral coordination due to the Jan–Teller effect. A survey of the Cambridge Structural Database showed that the octahedral coordination geometry is generally rare for pyrazole-bridged Cu(II) complexes. In the case of Cu(II) complexes with the 3-pyrazolecarboxylato ligands, no complexes with a similar octahedral coordination geometry have been reported. Biological research based on determination of the inhibition effect of the commercial fungicide Cabrio top and the newly synthesized complex on Ph. viticola were performed using the phytosanitary method
Numerical simulations of the Lagrangian averaged Navier–Stokes equations for homogeneous isotropic turbulence
Crystal structure of ethyl 3-(trifluoromethyl)-1H-pyrazole-4-carboxylate, C7H7F3N2O2
C7H7F3N2O2, monoclinic, P21/m (no. 11), a = 6.8088(8) Å, b = 6.7699(9) Å, c = 9.9351(12) Å, β = 105.416(3)°, V = 441.48(9) Å 3 , Z = 2, R gt ( F ) = 0.0398, wR ref ( F 2 ) = 0.1192, T = 200(2) K
A Large-Eddy Simulation Study of the Influence of Subsidence on the Stably Stratified Atmospheric Boundary Layer
A physical-space version of the stretched-vortex subgrid-stress model for large-eddy simulation
Revisiting the Local Scaling Hypothesis in Stably Stratified Atmospheric Boundary Layer Turbulence: an Integration of Field and Laboratory Measurements with Large-eddy Simulations
The `local scaling' hypothesis, first introduced by Nieuwstadt two decades
ago, describes the turbulence structure of stable boundary layers in a very
succinct way and is an integral part of numerous local closure-based numerical
weather prediction models. However, the validity of this hypothesis under very
stable conditions is a subject of on-going debate. In this work, we attempt to
address this controversial issue by performing extensive analyses of turbulence
data from several field campaigns, wind-tunnel experiments and large-eddy
simulations. Wide range of stabilities, diverse field conditions and a
comprehensive set of turbulence statistics make this study distinct
Large-eddy simulation sensitivities to variations of configuration and forcing parameters in canonical boundary-layer flows for wind energy applications
The sensitivities of idealized large-eddy simulations (LESs) to variations of
model configuration and forcing parameters on quantities of interest to wind
power applications are examined. Simulated wind speed, turbulent fluxes,
spectra and cospectra are assessed in relation to variations in two physical
factors, geostrophic wind speed and surface roughness length, and several
model configuration choices, including mesh size and grid aspect ratio,
turbulence model, and numerical discretization schemes, in three different
code bases. Two case studies representing nearly steady neutral and
convective atmospheric boundary layer (ABL) flow conditions over nearly flat
and homogeneous terrain were used to force and assess idealized LESs, using
periodic lateral boundary conditions. Comparison with fast-response velocity
measurements at 10 heights within the lowest 100 m indicates that most model
configurations performed similarly overall, with differences between observed
and predicted wind speed generally smaller than measurement variability.
Simulations of convective conditions produced turbulence quantities and
spectra that matched the observations well, while those of neutral
simulations produced good predictions of stress, but smaller than observed
magnitudes of turbulence kinetic energy, likely due to tower wakes
influencing the measurements. While sensitivities to model configuration
choices and variability in forcing can be considerable, idealized LESs are
shown to reliably reproduce quantities of interest to wind energy
applications within the lower ABL during quasi-ideal, nearly steady neutral
and convective conditions over nearly flat and homogeneous terrain.</p
Lessons learned in coupling atmospheric models across scales for onshore and offshore wind energy
The Mesoscale to Microscale Coupling team, part of the
U.S. Department of Energy Atmosphere to Electrons (A2e) initiative, has
studied various important challenges related to coupling mesoscale models to
microscale models for the use case of wind energy development and operation.
Several coupling methods and techniques for generating turbulence at the
microscale that is subgrid to the mesoscale have been evaluated for a
variety of cases. Case studies included flat-terrain, complex-terrain, and
offshore environments. Methods were developed to bridge the terra incognita, which scales from
about 100 m through the depth of the boundary layer. The team used
wind-relevant metrics and archived code, case information, and assessment
tools and is making those widely available. Lessons learned and discerned
best practices are described in the context of the cases studied for the
purpose of enabling further deployment of wind energy.</p