Physicochemical quality of directly sold raw milk in Hungary

The importance of short food supply chains is increasing in the food sector, and direct selling is a promising alternative to commercial chains in dairy trade. Several channels and practices of direct raw milk sales exist in Hungary. Because short food supply chains in the Hungarian dairy sector have not yet been investigated in detail, we have little or no knowledge on the composition of directly sold raw milk. For this reason, a 9-month study was undertaken from June 2013 through February 2014, wherein directly sold raw bovine milk samples were tested for fat, protein, lactose, and solids-not-fat contents and for freezing point. A total of 21 direct sellers located in Budapest, Hungary were sampled twice a month. The results were compared to the official Hungarian raw milk quality data referring to the same period. The direct milk vendors involved in this study were found to sell raw milk with reduced levels of lactose and solids-not-fat and elevated freezing points, compared to the national raw milk data. The findings of this research underline the need for stricter regulations and control with respect to direct raw milk sales in the country

Symmetry analysis of internal rotation

Barriers of infinite (or very large) height prevent certain rearrangements of the atoms in a molecule from occurring and thus the complete nuclear permutation inversion (CNPI) group of the molecule can be reduced. Using the example of acetaldehyde molecule, it was pointed out that some barriers of infinite height, in addition to reducing the CNPI group, constrain torsional dynamics explicitly and influence how the torsional coordinate transforms under the MS group. It was proved that the symmetry properties of the torsional potential do not depend on the geometrical symmetry of either the top or the frame.The authors would like to thank Projects E-10/2001 of the Hungarian–Spanish Intergovernmental Cooperations on Science and Technology, BFM2000-1106 and BFM2001- 2315 of the Ministerio de Ciencia y Technologia (Spain), and Grant Nos. OTKA T034327 and T033074 for support.Peer Reviewe

Exactly solvable 1D model explains the low-energy vibrational level structure of protonated methane

A new one-dimensional model is proposed for the low-energy vibrational quantum dynamics of CH5+ based on the motion of an effective particle confined to a 60-vertex graph ${\Gamma}_{60}$ with a single edge length parameter. Within this model, the quantum states of CH5+ are obtained in analytic form and are related to combinatorial properties of ${\Gamma}_{60}$. The bipartite structure of ${\Gamma}_{60}$ gives a simple explanation for curious symmetries observed in numerically exact variational calculations on CH5+

A new ab initio ground-state dipole moment surface for the water molecule

A valence-only (V) dipole moment surface (DMS) has been computed for water at the internally contracted multireference configuration interaction level using the extended atom-centered correlation-consistent Gaussian basis set aug-cc-pV6Z. Small corrections to these dipole values, resulting from core correlation (C) and relativistic (R) effects, have also been computed and added to the V surface. The resulting DMS surface is hence called CVR. Interestingly, the C and R corrections cancel out each other almost completely over the whole grid of points investigated. The ground-state CVR dipole of H(2) (16)O is 1.8676 D. This value compares well with the best ab initio one determined in this study, 1.8539+/-0.0013 D, which in turn agrees well with the measured ground-state dipole moment of water, 1.8546(6) D. Line intensities computed with the help of the CVR DMS shows that the present DMS is highly similar to though slightly more accurate than the best previous DMS of water determined by Schwenke and Partridge [J. Chem. Phys. 113, 16 (2000)]. The influence of the precision of the rovibrational wave functions computed using different potential energy surfaces (PESs) has been investigated and proved to be small, due mostly to the small discrepancies between the best ab initio and empirical PESs of water. Several different measures to test the DMS of water are advanced. The seemingly most sensitive measure is the comparison between the ab initio line intensities and those measured by ultralong pathlength methods which are sensitive to very weak transitions

Two-electron relativistic corrections to the potential energy surface, and vibration-rotation levels of water

Two-electron relativistic corrections to the ground-state electronic energy of water are determined as a function of geometry at over 300 points. The corrections include the two-electron Darwin term (D2) of the Coulomb–Pauli Hamiltonian, obtained at the cc-pVQZ CCSD(T) level of theory, as well as the Gaunt and Breit corrections, calculated perturbationally using four-component fully variational Dirac–Hartree–Fock (DHF) wavefunctions and two different basis sets. Based on the calculated energy points, fitted relativistic correction surfaces are constructed. These surfaces are used with a high-accuracy ab initio nonrelativistic Born–Oppenheimer (BO) potential energy hypersurface to calculate vibrational band origins and rotational term values for H216O. The calculations suggest that these two-electron relativistic corrections, which go beyond the usual kinetic relativistic effects and which have so far been neglected in rovibrational calculations on light many-electron molecular systems, have a substantial influence on the rotation–vibration levels of water. The three effects considered have markedly different characteristics for the stretching and bending levels, which often leads to fortuitous cancellation of errors. The effect of the Breit interaction on the rovibrational levels is intermediate between the effect of the kinetic relativistic correction and that of the one-electron Lamb-shift effect