300 research outputs found
The v2 = 1, 2 and v4 = 1 bending states of 15NH3 and their analysis at experimental accuracy
No full text15NH3 is the object of extensive investigation due to the central role of ammonia in astronomical sciences and to the complexity of modeling its interacting vibrationally-excited states. Of major interest in astrochemistry is the determination of the 14N/15N ratio in Space, characterized by unexpected variability among different Solar System objects and reservoirs. Recently, the spectroscopic analysis of ground and v2 = 1 a, s states of 15NH3 has been completed at experimental accuracy. Here the characterization of the a, s inversion symmetry levels of v2 = 1, 2 and v4 = 1 states is presented. New spectra of 15NH3 have been recorded from 325 to 2000 cm1 at a resolution ranging from 0.00096 cm1 to 0.003 cm1 , using the Canadian Light Source synchrotron at CLS. 7518 transitions covering nine bands, nu2, 2nu2, nu4, 2nu2 - nu2, nu4 -nu2, 2nu2- nu4 and the inversion-rotation transitions in the excited states, have been fitted simultaneously. The effective Hamiltonian adopted includes all symmetry allowed interactions between and within the studied excited states, according to the most recent results on ammonia. The transitions have been reproduced at experimental accuracy using 185 spectroscopic parameters, determined with high precision. The leading diagonal parameters, Gv, B, C, D’s, compare well with those of 14NH3. The wavenumbers of the assigned transitions are compared with their theoretically predicted values. An improved set of ground state parameters is also derived. These results improve noticeably the wavenumber line list in the HITRAN data base
Spectroscopic characterization of the v2 = 3 and v2 = v4 = 1 states for 15NH3 from high resolution infrared spectra
No full textThe a, s inversion levels of v2 = 3 and v2 = v4 = 1 vibration states of 15NH3 are studied from high resolution infrared spectra up to 3200 cm−1. Spectra were recorded from 60 to 2000 cm−1 using the Bruker IFS 125 interferometer located at the Canadian Light Source and from 1900 to 3200 cm−1 using the Bomem DA 008 in Bologna. Transitions in 3ν2 and ν2+ν4, in the 3ν2 ← ν2, ν2+ν4 ← ν2, 3ν2 ← 2ν2, ν2+ν4 ← 2ν2, 3ν2 ← ν4, ν2+ν4 ← ν4, and 3ν2 ↔ ν2+ν4 hot bands, and the rotation-inversion transitions in 3ν2 and ν2+ν4 have been observed. 5770 transitions with Jmax′/Kmax′ up to 15 have been assigned, including 395 perturbation allowed ones. All transitions were fitted simultaneously on the basis of a rotation-inversion Hamiltonian which includes distortion constants up to 10th power in the angular momentum and all symmetry allowed interaction parameters between and within the a, s inversion levels of v2 = 3 and v2 = v4 = 1. The term values of the lower levels of transitions have been calculated using the parameters recently derived for the ground and v2 = 1, 2 and v4 = 1 states. The data were reproduced at experimental accuracy. The results are compared with those of 14NH3. The experimental transitions are compared with their theoretically predicted values. The list of assignments is supplied as supplementary material. The present results noticeably improve the wavenumber line list in the HITRAN 2016 data base
Mono- and di-deuterated ammonias: Far-infrared spectra and spectroscopic parameters in the ground state
No full textTransitions of NH2D and ND2H have been detected in the high resolution spectrum of 14ND3 recorded at unapodized resolution of 0.00096 cm−1 in the region 60–600 cm−1 using the Bruker IFS 125 Fourier transform spectrometer located at the synchrotron far-infrared beamline, Canadian Light Source. In this study we report on the observation and analysis of the spectrum for the ground state of NH2D and ND2H. 2153 rotation and rotation-inversion transitions, with J up to 24, were assigned for NH2D, and 3214 transitions, with J up to 28, for ND2H. The newly assigned transitions, together with those present in the literature, were fitted on the basis of a Watson-type S reduced Hamiltonian using the IIIr and IIIl representations for NH2D and ND2H, respectively. The model Hamiltonian includes terms up to the 10th power of the angular momentum and vibration–rotation interaction terms between the inversion states. Precise and extended sets of spectroscopic effective parameters were derived for both isotopologues as results of least squares weighted fit procedures that reproduce the transition wavenumbers at experimental accuracy
Physico-chemical characteristics and antimicrobial studies of silver doped hydroxyapatite
No full textThe high resolution spectrum of 15NH3 in the far-infrared: Rotation-inversion transitions in the ground, v2=1, 2 and v4=1 states
No full textThe high resolution spectrum of 15NH3 has been recorded at unapodized resolution of 0.00096 cm−1 in the region 60–600 cm−1 using the Bruker IFS 125 Fourier transform spectrometer located at the far-infrared beam-line, Canadian Light Source. We report on the observation and analysis of the rotation-inversion spectrum in the ground, v2=1, 2 and v4=1 states. All the rotation-inversion transitions in the ground state together with the pure inversion transitions present in the literature were fitted simultaneously on the basis of a rotation-inversion Hamiltonian which includes distortion constants up to the 12th power in the angular momentum and the Δk=±3 and Δk=±6 interaction terms. A set of effective parameters was also obtained for the v2=1 state adopting the same theoretical model. For the v2=2 and v4=1 states only a list of observed transitions is reported. The wavenumbers of all the assigned transitions were compared with their theoretically predicted values [S.N. Yurchenko, J. Quant. Spectrosc. Radiat. Transf. 2015, 152, 28]. The present results noticeably improve the wavenumber line list in the HITRAN data base [L. S. Rothman et al. J. Quant. Spectrosc. Radiat. Transf.2013, 130, 4].SCOPUS: ar.jinfo:eu-repo/semantics/publishe
The ground, v2 = 1, 2 and v4 = 1 states of 14ND3 analyzed at experimental accuracy
No full textAmmonia is the object of extensive investigations due to the peculiar pattern of its interacting vibration states and its central role in astronomical sciences. 14ND3 is of interest in astrochemistry because the determination of deuterium fractionation ratios in ammonia and its deuterated isotopologues contributes to a deeper knowledge of the chemistry in the cold, dense cores of the interstellar medium. Here, the ground, v2 = 1, 2 and v4 = 1, a, s states of 14ND3 are analyzed thanks to new spectra recorded with the Canadian Light Source synchrotron, from 60 to 1500 cm-1 at a resolution ranging from 0.00096 to 0.003 cm-1. Overall, 7765 inversion, rotationinversion, and vibration-rotation-inversion transitions in v2, 2v2, v4, 2v2 F v2, 2v2 F v4, v4 F v2, v2 F v2, 2v2 F 2v2, and v4 F v4 have been fitted simultaneously to characterize the s and a levels of the excited states. 4021 and 2388 transitions were assigned in the cold and hot bands, respectively, and 150 inversion and 1206 inversion-rotation transitions in v2 = 1, 2 and v4 = 1. The effective Hamiltonian adopted includes all symmetry allowed interactions between and within the studied excited states, according to the most recent results on ammonia. The transitions have been reproduced at experimental accuracy using 118 spectroscopic parameters, determined with high precision. In addition, a new analysis of the ground state has been performed. 9256 data have been fitted, 78 inversion and 837 rotation-inversion transitions, and 8341 ground state combination differences. An improved set of parameters and term values are derived thanks to the increased precision of the newly assigned rotation-inversion transitions with J/ K values up to 31/30 and to the larger number of the ground state combination differences
Far-infrared spectra and ground state spectroscopic parameters of 15NH2D
No full textSpectra for 15NH2D were recorded in the 65−360 cm−1 range.
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FT spectrometer and synchrotron source at the Canadian Light Source were used.
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a-Type and c-type transitions involving the (s) and (a) levels were identified.
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1481 Transitions were fitted to 49 parameters of an inversion–rotation Hamiltonian
Application of biocompatible magnetite nanoparticles for the removal of arsenic and copper from water
No full textDairy Cows’ Welfare Assessment in a Farm from South-Eastern Romania
No full textAbstractThis study aimed to assess the welfare level of dairy cows in a farm from the South-Eastern Romania, in a mixed house with free-stalls inner space division. The welfare level was established by using an integrative numerical assessment system – the Austrian Animal Needs Index 35L/2000. There were scored 26 objective welfare indicators within the five areas of influence: locomotion, social interactions, flooring, light and air, stockmanship. In order to assess and score some indicators, there were used modern devices (LX 1102 light meter, Drager Pac 7000 ammonia analyzer, Testo 405 V1 thermo-anemometer, SL 4012 sound meter). Moreover, for increasing the objectivity in measuring and scoring animal cleanliness within the fifth area on influence there was used Hygiene Score Card. Analyzing the results, it could be noticed that the highest scored indicators were those within the Locomotion and Social interactions areas (as expected, considering the loose-system applied in the studied farm). The lowest scored areas were Flooring and Light and air, the critical indicators being light (uneven lighting and some low intensity values: 28-30 Lx) and outdoor areas cleanliness, resulting in poor animal cleanliness. In spite of the mentioned negative aspects, the overall ANI 35L score (30.5 points) reflects a good welfare, but the score could be validated on the condition that the light in the shelter is corrected. Addressing this issue along with the cleanliness of the outdoor areas may improve the welfare level to the excellent rating and may also increase the milk production
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