Search results for "rotation"

Spherical top data system (STDS) software for the simulation of spherical top spectra

1998

Abstract The Spherical Top Data System (STDS) software package for the simulation of spherical top spectra is presented. It consists of a single UNIX script with self-explanatory arguments allowing the non-expert user to calculate spectra from the results of the high resolution analyses performed over the recent decades on this type of molecules. More than one hundred parameter files are presently available including various band systems of 16 molecular species (among which methane is the most documented) and various types of calculations: rovibrational energy levels, i.r. absorption, Raman scattering and Stark coefficients. STDS is freely accessible by anonymous ftp at jupiter.u-bourgogne.…

Rotation of methyl radicals in molecular solids.

2010

Electron spin resonance (ESR) measurements were carried out to study the rotation of methyl radicals (CH(3)) in solid carbon monoxide, carbon dioxide, and nitrogen matrices. The radicals were produced by dissociating methane by plasma bursts generated by a focused 193 nm ArF excimer laser radiation during the gas condensation on the substrate. The ESR spectra exhibit anisotropic features that persist over the temperature range examined, and in most cases this indicates a restriction of rotation about the C(2) symmetry axis. A nonrotating CH(3) was also observed in a CO(2) matrix. The intensity ratio between the symmetric (A) and antisymmetric (E) nuclear spin states was recorded as a functi…

EPR, ENDOR and TRIPLE resonance of amino-substituted 9,10-anthraquinone radicals and the rotation of the amino groups in the solution phase

1996

EPR, ENDOR and TRIPLE resonance spectra were recorded for 1-amino-9,10-anthraquinone (1-aminoAQ), 2-aminoAQ, 1,2-diaminoAQ, 1.4-diaminoAQ, 1,5-diaminoAQ and 2,6-diaminoAQ anion radicals in the solution phase. The rotation of the amino groups is discussed with reference to the experimental data. Rotation barrier calculations were carried out using B3PW91/3-21G* density functional method. The amino groups at positions 1, 4, 5, 8 were found not to be in rotational movement up to the EPR time-scale.

Observation of octupole structures in radon and radium isotopes and their contrasting behavior at high spin

1997

Multinucleon transfer reactions have been used, for the first time, to populate high-spin bands of alternating parity states in {sup 218,220,222}Rn and {sup 222,224,226}Ra. The behavior of the angular momentum alignment with rotational frequency for the Rn isotopes is very different when compared with Ra and Th isotopes with N{approx}134, indicating a transition from octupole vibrational to stable octupole deformation. Throughout the measured spin range the values of {vert_bar}D{sub 0}/Q{sub 0}{vert_bar} remain constant for {sup 222}Ra and {sup 226}Ra and have a very small value for {sup 224}Ra, suggesting that the charge and mass distributions are not affected appreciably by rotations. {co…

Raman spectroscopy and crystal-field split rotational states of photoproducts CO and H2 after dissociation of formaldehyde in solid argon

2012

Raman signal is monitored after 248 nm photodissociation of formaldehyde in solid Ar at temperatures of 9–30 K. Rotational transitions J = 2 ← 0 for para-H2 fragments and J = 3 ← 1 for ortho-H2 are observed as sharp peaks at 347.2 cm−1 and 578.3 cm−1, respectively, which both are accompanied by a broader shoulder band that shows a split structure. The rovibrational spectrum of CO fragments has transitions at 2136.5 cm−1, 2138.3 cm−1, 2139.9 cm−1, and 2149 cm−1. To explain the observations, we performed adiabatic rotational potential calculations to simulate the Raman spectrum. The simulations indicate that the splitting of rotational transitions is a site effect, where H2 molecules can resi…

Molecular dynamics in low-molar and polymeric ferroelectric liquid crystals

1991

Broadband dielectric spectroscopy covering the frequency range from 10−1 Hz to 109 Hz was employed to study the molecular dynamics in low-molar and polymeric ferrroelectric liquid crystals. At frequencies below 106 Hz the ferroelectric modes, soft and Goldstone mode are observed. In the frequency regime from 106 Hz to 109 Hz a fast relaxation process is found, which is assigned to the hindered rotation of the mesogens around their long molecular axis. It turns out that the molecular dynamics is not principally different between low-molar and polymeric systems.

Differential Cross Sections and Product Rovibrational Distributions for (16)O + (32)O2 and (18)O + (36)O2 Collisions.

2015

We report rotationally resolved opacity functions, product rotational distributions, and differential cross sections for the (16)O + (16)O(16)O (v = 0,j = 1) → (16)O(16)O (v' = 0,j') + (16)O and (18)O + (18)O(18)O (v = 0,j = 1) → (18)O(18)O (v' = 0,j') + (18)O collisions calculated by a time-independent quantum mechanical method employing one of the latest potential energy surface of ozone [ Dawes ; et al. J. Chem. Phys. 2013 , 139 , 201103 ]. The results obtained for both collisional systems in the energy range 0.001-0.2 eV are examined, and interesting mass scaling effects have been discovered. The shapes of product angular distributions suggest a transition from an indirect to a direct s…

5,11,17,23-Tetranitro-25,26,27,28-tetrapentyloxycalix[4]arene

2005

The mol­ecule of the title compound, C48H60N4O12, is located on a crystallographic twofold rotation axis. It is found in the typical pinched cone conformation. The dihedral angles between the reference plane (defined by the C atoms of the methyl­ene bridges) and the benzene rings are 83.33 (6) and 141.61 (5)°.

Metodi automatici di analisi e caratterizzazione di esami radiologici del massiccio facciale.

L'obiettivo di questo lavoro è lo sviluppo di algoritmi e procedure di analisi di referti radiografici digitali di tipo CBCT delle strutture della mandibola e dell’apparato dentario. In particolare, mediante un’opportuna campagna di sperimentazione, in collaborazione con i reparti di radiologia ed odontoiatria del Policlinico di Palermo, è stata realizzata un procedura in grado di: • eliminare i problemi di sovrapponibilità dei referti tridimensionali effettuati in tempi successivi; • identificare lo spazio parodontale su indagini CBCT per la valutazione dei possibili difetti nello stesso e prevedere l’insorgenza di parodontiti. • individuare gli elementi di maggiore interesse medico caratt…

Exploring the development of mental rotation and computational skills in elementary students through educational robotics

2022

Abstract Interest in educational robotics has increased over the last decade. Through various approaches, robots are being used in the teaching and learning of different subjects at distinct education levels. The present study investigates the effects of an educational robotic intervention on the mental rotation and computational thinking assessment in a 3rd grade classroom. To this end, we carried out a quasi-experimental study involving 24 third-grade students. From an embodied approach, we have designed a two-hour intervention providing students with a physical environment to perform tangible programming on Bee-bot. The results revealed that this educational robotic proposal aimed at map…