A Quantum Theoretical Basis for Some Spectra – Structure Correlations in Crystalline Hydrates

Starting with the perturbation theory and the Hellmann-Feynmann theorem, an attempt was made to derive a fundamental theoretical basis for some frequency – structure correlations in crystalline hydrates. It was found that within a few reasonable approximations, a satisfactory theoretical background may be found for the νOH(OD) versus RO⋅⋅⋅O, as well as for the –2XOH(OD) versus νOH(OD) correlations (νOH(OD) is the spectroscopically measured wavenumber of the OH(OD) stretching vibration, RO⋅⋅⋅O is the hydrogen bond distance, and X is the anharmonicity of vibration). The OH(OD) oscillators were treated as mixed cubic – quartic anharmonic systems. The influence of hydrogen bonding on these oscillators was introduced through the changes in the harmonic diagonal force constants (as proposed by Sceats and Rice1), the other diagonal terms in the potential energy expression being regarded as practically unchanged in the course of the hydrogen bonding. The parameters obtained by empirical correlations, within the proposed model, describe the dependence of the intramolecular potential of the uncoupled OH(OD) species on the hydrogen bond strength

A Quantum Theoretical Basis for Some Spectra – Structure Correlations in Crystalline Hydrates

Starting with the perturbation theory and the Hellmann-Feynmann theorem, an attempt was made to derive a fundamental theoretical basis for some frequency – structure correlations in crystalline hydrates. It was found that within a few reasonable approximations, a satisfactory theoretical background may be found for the νOH(OD) versus RO⋅⋅⋅O, as well as for the –2XOH(OD) versus νOH(OD) correlations (νOH(OD) is the spectroscopically measured wavenumber of the OH(OD) stretching vibration, RO⋅⋅⋅O is the hydrogen bond distance, and X is the anharmonicity of vibration). The OH(OD) oscillators were treated as mixed cubic – quartic anharmonic systems. The influence of hydrogen bonding on these oscillators was introduced through the changes in the harmonic diagonal force constants (as proposed by Sceats and Rice1), the other diagonal terms in the potential energy expression being regarded as practically unchanged in the course of the hydrogen bonding. The parameters obtained by empirical correlations, within the proposed model, describe the dependence of the intramolecular potential of the uncoupled OH(OD) species on the hydrogen bond strength

THE INFLUENCE OF FOLIAR FERTILIZATION WITH ORGANIC FERTILIZERS ON THE YIELD AND THE CHEMICAL CONTENT OF POTATOES GROWN IN STRUMICA REGION

The effect of foliar fertilization with organic fertilizers on the yield and the chemical content of potatoes grown in Strumica region were studied, in the period from the year of 2011-2012. The experiment was set in four variants and three repetitions. The variants in the experiment were: Control (no-fertilizing variant); Humusil (organic matter 1.86%; organic carbon 1.08%; humin acids 0.14%; N 224 mg/L; P2O5 71 mg/L; K2O 1024 mg/L; CaO 180 mg/L); Humustim (organic matter 58.63 %; dry matter 12.38 %; humin acids 20.40 %; fulvo acids 2.15%; N 3%; P2O5 1.02%; K2O 7.92%; Ca 3.70 %; Mg 1.03%); Ingrasamant foliar (N 0 %; P2O5 130 g/L; K2O 130 g/L; ME in helate form and plant extracts 0.005 g/L). The experiment was arranged in 12 rows and in each variant and repetition was involved 100 plants, total in all experiment were involved 1200 plants. The planting was made in rows at a distance of 60 cm row by row and 20 cm in the rows. The row’s length was 20 m. Three foliar treatments were applied with given above fertilizers at a concentration of 0.4%. The soil where the experiment was carried had a good fertility with nitrogen, phosphorus and potassium. The foliar fertilization had a positive influence on potatoes yield in all of the variants treated with different organic fertilizers. The highest potatoes yield of 54.62 t ha-1 was established in variant 4. The foliar fertilization had a positive influence on the chemical content of tubers potato, too. In three variants treated with different fertilizers, higher content of all tested parameters was found, compared to the control untreated variant. The highest average content of vitamin C (2.60 mg/100g), phosphorus (0.90 %), and potassium (1.30 %) was determined in the tubers potato in variant 3

GIADA performance during Rosetta mission scientific operations at comet 67P

The Grain Impact Analyser and Dust Accumulator (GIADA) instrument onboard Rosetta studied the dust environment of comet 67P/Churyumov–Gerasimenko from 3.7 au inbound, through perihelion, to 3.8 au outbound, measuring the dust flow and the dynamic properties of individual particles. GIADA is composed of three subsystems: 1) Grain Detection System (GDS); 2) Impact Sensor (IS); and 3) Micro-Balances System (MBS). Monitoring the subsystems’ performance during operations is an important element for the correct calibration of scientific measurements. In this paper, we analyse the GIADA inflight calibration data obtained by internal calibration devices for the three subsystems during the period from 1 August 2014 to 31 October 2015. The calibration data testify a nominal behaviour of the instrument during these fifteen months of mission; the only exception is a minor loss of sensitivity for one of the two GDS receivers, attributed to dust contamination

Accelerated wound healing phenotype in Interleukin 12/23 deficient mice

Background: The concept that a strong inflammatory response involving the full complement of cytokines and other mediators is critical for unimpaired healing has been challenged by wound healing studies using transgenic and knockout (KO) mice. The present study explored the effect of abrogation of the p40 subunit, which is shared by the pro-inflammatory cytokines interleukin (IL)-12 and IL-23, on wound closure of excisional oral mucosal wounds

Hydrophilic titanium surface‐induced macrophage modulation promotes pro‐osteogenic signalling

Objectives: As biomaterial‐induced modulation of mediators of the immune response may be a potential therapeutic approach to enhance wound healing events, the aim of this study was to delineate the effects of titanium surface modification on macrophage phenotype and function. Material and methods: Rodent bone marrow‐derived macrophages were polarized into M1 and M2 phenotypes and cultured on micro‐rough (SLA) and hydrophilic modified SLA (modSLA) titanium discs. Macrophage phenotype and cytokine secretion were subsequently assessed by immunostaining and ELISA, respectively. Osteoblast gene expression in response to culture in the M1 and M2 macrophage conditioned media was also evaluated over 7 days by RT‐PCR. Results: M1 macrophage culture on the modSLA surface promoted an M2‐like phenotype as demonstrated by marked CD163 protein expression, Arg1 gene expression and the secretion of cytokines that significantly upregulated in osteoblasts the expression of genes associated with the TGF‐ß/BMP signalling pathway and osteogenesis. In comparison, M2 macrophage culture on SLA surface promoted an inflammatory phenotype and cytokine profile that was not conducive for osteogenic gene expression. Conclusions: Macrophages are able to alter or switch their phenotype according to the signals received from the biomaterial surface. A hydrophilic micro‐rough titanium surface topography elicits a macrophage phenotype associated with reduced inflammation and enhanced pro‐osteogenic signalling

A semi-classical over-barrier model for charge exchange between highly charged ions and one-optical electron atoms

Absolute total cross sections for electron capture between slow, highly charged ions and alkali targets have been recently measured. It is found that these cross sections follow a scaling law with the projectile charge which is different from the one previously proposed basing on a classical over-barrier model (OBM) and verified using rare gases and molecules as targets. In this paper we develop a "semi-classical" (i.e. including some quantal features) OBM attempting to recover experimental results. The method is then applied to ion-hydrogen collisions and compared with the result of a sophisticated quantum-mechanical calculation. In the former case the accordance is very good, while in the latter one no so satisfactory results are found. A qualitative explanation for the discrepancies is attempted.Comment: RevTeX, uses epsf; 6 pages text + 3 EPS figures Journal of Physics B (scehduled March 2000). This revision corrects fig.

The dust-to-ices ratio in comets and Kuiper belt objects

Comet 67P/Churyumov-Gerasimenko (67P hereinafter) is characterized by a dust transfer from the southern hemi-nucleus to the night-side northern dust deposits, which constrains the dust-to-ices mass ratio inside the nucleus to values a factor of 2 larger than that provided by the lost mass of gas and non-volatiles. This applies to all comets because the gas density in all night comae cannot prevent the dust fallback. Taking into account Grain Impact Analyser and Dust Accumulator (GIADA) data collected during the entire Rosetta mission, we update the average dust bulk density to ρD=785 +520/−115 $\rho {}{}_{\rm D} = 785_{-115}^{+520}$ kg m$^-3$ that, coupled to the 67P nucleus bulk density, confirms an average dust-to-ices mass ratio δ = 7.5 inside 67P. The improved dust densities are consistent with a mixture of (20 ± 8) per cent of ices, (4 ± 1) per cent of Fe sulphides, (22 ± 2) per cent of silicates and (54 ± 5) per cent of hydrocarbons, on average volume abundances. These values correspond to solar chemical abundances, as suggested by the elemental C/Fe ratio observed in 67P. The ice content in 67P matches that inferred in Kuiper belt objects, (20 ± 12) per cent on average volume abundance and suggests a water content in all trans-Neptunian objects lower than in CI chondrites. The 67P icy pebbles and the dust collected by GIADA have a microporosity of (49 ± 5) and (59 ± 8) per cent, respectively

On the similarity of dust flows in the inner coma of comets

The atmosphere of a comet is formed by the sublimation, due to solar illumination, of its volatile component and the dust particles ejected from its nucleus and entrained by the gas flow. Contemporary dusty-gas coma models take into account numerous physical processes occurring in the coma and a complex geometry of the nucleus. For the description of the dusty-gas flow in the coma, such models introduce a large number of governing parameters characterizing physical properties and processes. The relative role of these processes is not easy to ascribe therefore a relevant inter-comparison of model results becomes difficult. The present work introduces a set of universal, dimensionless parameters, which characterize the dust motion in the inner cometary coma. This approach allows one to: (i) reduce the number of parameters for analysis; (ii) reveal dust flows similarities; (iii) rescale the available numerical solutions. The present work demonstrates application of this approach to a realistic coma model. Description of dust motion with dimensionless parameters allows us to make a parametric study for a broad range of conditions and to find simple analytic approximations (via a polynomial function) of the numerical results suitable for rough estimations of dust density in the coma