Search results for " set"
showing 10 items of 2095 documents
Complete basis set prediction of methanol isotropic nuclear magnetic shieldings and indirect nuclear spin-spin coupling constants (SSCC) using polari…
2009
Efficient B3LYP and BHandH density functionals were used to estimate methanol's nuclear magnetic isotropic shieldings and spin–spin coupling constants in the basis set limit. Polarization-consistent pcS-n and pcJ-n (n = 0, 1, 2, 3 and 4), and segmented contracted XZP, where X = D, T, Q and 5, basis sets were used and the results fitted with simple mathematical formulas. The performance of the methods was assessed from comparison with experiment and higher level calculations. 1J(CH) and 3J(HH) values were determined from very diluted solutions in deuterochloroform and compared with theoretical predictions. The agreement between complete basis set (CBS) density functional theory (DFT) predict…
Gortina. Nuovi dati dagli scavi dell’insediamento di Profitis Ilias
2018
Recent research in the Iron age settlement on the hill of Profitis Ilias (Gortyn) revealed part of a building belonging to the latest phase of the village (VIII-VII cent. B.C.), and perhaps intended to some civic function. Its building process involved the demolition of a part of a thick wall dated in the Protogeometric age, possibly to be identified with the defense wall of the former settlement. The stratigraphy in the building area showed significant evidence for the site occupation after the abandonment of the village.
Urea as a thinning agent in olive: The influence of concentration and time of application
1992
Urea was tested as chemical thinner on olive cv. Nocellara del Belice using three concentrations (2, 4 and 6%) applied at full bloom (FB), FB + 10 and FB + 20 days. Urea reduced fruit set significantly only when applied at FB + 20 days, the fruitlet stage. Final fruit set was reduced by about 50% compared with the untreated control (6% FB + 20 days). Crop load and fruit characteristics were both affected by the treatments.
Generating Winter Wheat Global Crop Calendars in the Framework of Worldcereal
2021
In this study we present a methodology to develop a global winter wheat crop calendar based on the existing crop calendar products from FAO and GEOGLAM Crop Monitor in the framework of the WorldCereal project. It is based on integrating both datasets by building on the accuracy from Crop Monitor and the spatial resolution from the Food and Agriculture Organization of the United Nations (FAO). Additionally, given the global extent of WorldCereal and the gaps that both products present at global scale, we simulated the crop calendars in those areas not covered by any of the products. To do so, we integrated a Regression-Kriging model considering as training data the calendars derived from bot…
Value congruence in health care priority setting: social values, institutions and decisions in three countries
2014
AbstractMost developed democracies have faced the challenge of priority setting in health care by setting up specialized agencies to take decisions on which medical services to include in public health baskets. Under the influence of Daniels and Sabin’s seminal work on the topic, agencies increasingly aim to fulfil criteria of procedural justice, such as accountability and transparency. We assume, however, that the institutional design of agencies also and necessarily reflects substantial value judgments on the respective weight of distributive principles such as efficiency, need and equality. The public acceptance of prioritization decisions, and eventually of the health care system at lar…
Older women's personal goals and exercise activity: an 8-year follow-up.
2013
This study investigated the associations of personal goals with exercise activity, as well as the relationships between exercise-related and other personal goals, among older women. Both cross-sectional and longitudinal designs were used with a sample of 308 women ages 66–79 at baseline. Women who reported exercise-related personal goals were 4 times as likely to report high exercise activity at baseline than those who did not report exercise-related goals. Longitudinal results were parallel. Goals related to cultural activities, as well as to busying oneself around the home, coincided with exercise-related goals, whereas goals related to own and other people’s health and independent living…
Ab initio modeling of radiation damage in MgF2 crystals
2014
Abstract MgF2 with a rutile structure is important radiation-resistant material with numerous applications due to its transparency from vacuum ultraviolet to infrared range of photon energies. We present and discuss the results of calculations for basic radiation defects in this crystal. The study is based on the large scale ab initio DFT calculations using hybrid B3PW exchange–correlation functional and atomic basis set. We analyzed the electronic structure, atomic displacements, charge density distribution as well as defect formation energies using large supercells. We compared properties of close and well separated F−H (Frenkel) defect pairs as well as individual defects. We simulated al…
Coin metal adsorption on defective MgO(001) surface: ab initio study
2005
First principles slab calculations have been performed for Ag and Cu adsorption on periodically distributed point defects (a single O2– or Mg2+ vacancy per 2×2 surface supercell) on the non-polar MgO(001) substrate. Using the procedure implemented in the CRYSTAL-03 code, both Fs and Vs centers were modeled by retaining in the vacancy the basis set of the missing O2– and Mg2+ ions, respectively, with the local relaxation of the nearest substrate ions. Adsorption of metal atom over the Fs center (2.4 eV vs. 2.1 eV per Cu and Ag adatoms, respectively) is much stronger as compared with regular O2− sites (0.6 eV vs. 0.4 eV, respectively). The Fs center donates a substantial charge towards Ag and…
[MoO2(SCPh2CO2)2]2− and [MoO(SCPh2CO2)2]− anion complexes. A theoretical structure characterization
1995
Abstract Geometry optimization of [MoO 2 (SCH 2 CO 2 ) 2 ] 2− and [MoO(SCH 2 CO 2 ) 2 ] − systems as models of [MoO 2 (SCPh 2 CO 2 ) 2 ] 2− and [MoO(SCPh 2 CO 2 ) 2 ] − anion complexes have been carried out at STO-3G, 3-21G, LANL1MB and LANL2DZ basis set levels. A comparison of the theoretical results and X-ray experimental data has been performed. STO-3G minimal basis set produces the best geometrical agreement, in particular the distances and orientations of the different ligands linked to molybdenum transition metal. A large structural overlap with STO-3G optimized geometry and X-ray data has been found for the [MoO 2 (SCPh 2 CO 2 ) 2 ] 2− and [MoO(SCPh 2 CO 2 ) 2 ] − anion complexes.
Why betaine crystallizes in high local C s symmetry. An ab initio MO and DFT study of anhydrous betaine and betaine monohydrate
1999
A theoretical study of the structure, charge distribution, rotational barrier and fundamental vibrations of anhydrous betaine (CH3)3NCH2COO (trimethylglycine) was carried out and compared with available experimental data. Calculations were carried out at HF, MP2 and B3LYP levels using a 6-31+G(d,p) basis set. The calculated rotational barrier of the betaine carboxylic group is 40.5 kJ/mol at the MP4(SDQ)/6-311G(d,p)//HF/6-31+G(d,p) level of theory. The rotation of the carboxylic group changes the molecule from a highly symmetric (C s ) conformation into a twisted conformation resulting in shortening of the molecule by about 50 pm. Natural population analysis (NPA) indicates intramolecular i…