Search results

1

Evaluation of Rotational g-Factor of ^{6}Li^{1}H and ^{6}Li^{2}H from Pure Rotational and Vibration-Rotational Spectra of LiH X^{1}Σ^{+}

100%

Molski M.

Acta Physica Polonica A

|

1997

|

vol. 92

|

issue 6

1117-1124

EN

A deformationally self-consistent procedure and dependent local parameters t_{0}^{Li}, t_{0}^{H} are applied to estimate the values of the rotational g-factor of ^{6}Li^{2}H g_{J=1} = -0. 279032(88) and ^{6}Li^{1}H g_{J=1} = -0.661020(32) in the rotational state J = 1, from pure rotational and vibration-rotational spectra of LiH X^{1} Σ^{+}.

2

Quantitative Analysis of Vibration-Rotational Spectra of Diatomic Molecules with (v,j)-Dependent Dynamical Reference Conformation. Application to LiH X^{1}Σ^{+}

100%

Molski M.

|

vol. 96

|

issue 6

713-723

EN

An extension of deformationally self-consistent approach to a quantitative analysis of adiabatic and nonadiabatic effects in vibration-rotational spectra of diatomic molecules is presented. We consider vibrational displacements of nuclei in the vicinity of dynamical reference conformation R_{vJ} that depends not only on the rotational quantum number J through the action of centrifugal force, but also on the vibrational v one, through nonadiabatic vibrational effects of high order. The method is applied to LiH X^{1}Σ^{+}; reported wave numbers of transitions are reproduced with σ̂=1.090 and F=5.98×10^{14} using 14 independently adjusted parameters and 14 constrained parameters t_{i=0-6}^{Li,H}, representing nonadiabatic rotational effects. The latter have been evaluated from the rotational g-factor and electric dipole moment of LiH, both electronically computed.

3

A Study on Possibility to Apply Piezoelectric Actuators for Active Reduction of Torsional Beams Vibrations

80%

Augustyn E., Kozień M.

|

vol. 125

|

issue 4A

A-164-A-168

EN

In this paper, the results of several tests concerning possible application of piezoelectric elements to reduce torsional vibrations of a beam are presented and discussed. The proposed method of application is a novel one. The piezoelectric elements are positioned in two pairs and glued to the beam at the chosen cross-section. These elements are activated using a harmonically varying voltage of the same amplitude and opposite in phase. Simulations are performed regarding the active reduction of the lowest natural frequencies of vibration of the fixed-free beam with the use of piezoelectric actuators. The results of these simulations are obtained by means of the finite element method (ANSYS).

4

Comparison of Active and Passive Damping of Plate Vibration by Piezoelectric Actuators - FEM Simulation

80%

Kozień M., Kołtowski B.

Acta Physica Polonica A

|

2011

|

vol. 119

|

issue 6A

1005-1008

EN

Application of piezoelectric shunt elements, distributed in suitable configuration on the external surfaces of vibrating plate is one of the contemporary method of reduction of its vibroactivity. The two techniques are applied: passive one and active one. The aim of simulations was to compare the minimisation effect for the two attempts. The plate was excited by point harmonic force with constant amplitude. Vibrations for the first mode were considered.

5

Simulation of Application of FGM Piezoelectric Actuators for Active Reduction of Beam Vibrations

80%

Ferdek U., Kozień M.

Acta Physica Polonica A

|

2013

|

vol. 123

|

issue 6

1044-1047

EN

In the paper results of simulation of active reduction of vibration of the free-fixed beam by piezoelectic actuators made of functionally graded materials are presented. The aim of simmulation was to estimate sensitivity of the process of reduction. The effect of the level of gradation of material properties and amplitude of the applied voltage on effectiveness of the reduction process was analyzed. The analysis was reduced to the case of excited vibrations of the first mode and was performed by application of the finite element package Ansys.

6

Reanalysis of the Ångström System (B^1 Σ^{+} - A^1Π) in the ^{13}C^{16}O Isotopic Molecule

80%

Hakalla R., Szajna W., Zachwieja M., Kępa R.

Acta Physica Polonica A

|

2012

|

vol. 122

|

issue 4

674-682

EN

The emission spectrum of the Ångström system (B^1 Σ^{+} - A^1 Π) of ^{13}C^{16}O was obtained under high resolution with an accuracy estimated to be ± 0.002 cm^{-1} as an emission spectrum using a high accuracy dispersive optical spectroscopy. The light source was a hollow-cathode lamp with two anodes built in our laboratory, with a previously deposited small quantity of ^{13}C carbon on the electrodes. The emission from the discharge was observed with a plane grating spectrograph and recorded by a photomultiplier tube. In total 195 transition wave numbers belonging to the strongest 0-1 and 0-2 bands of the B - A system were precisely measured. The modern rotational reanalysis made it possible to verify the molecular information for the both combining states of the Ångström system. In particular the rovibrational constants for the B^1 Σ^{+} Rydberg state have been significantly improved (B_0 = 1.8625054(65) cm^{-1} and D_0=6.1384(52) × 10^{-6} cm^{-1}) and the obtained equilibrium rotational constants of this state are more accurate than known to date. Numerous rotational perturbations observed in the A^1 Π state were reanalysed and confronted with the previously known ones.

7

Stable and Unstable Rovibrational States of a Molecule

80%

Konarski J.

|

vol. 96

|

issue 3-4

353-357

EN

Stability of motions for different potential functions describing vibrational motions of rotating molecule has been discussed. It was shown that an equilibrium position for nonrotating r_{0} and rotating r_{J} molecules for almost all the examined potentials is a node, but for the molecule described by the soft body model a critical value of rotation quantum number J_{c} occurs above which r_{0} is a saddle point, and the stable motion may occur only around r_{J}.

8

Choosing of Optimal Voltage Amplitude of Four Pairs Square Piezoelectric Elements for Minimization οf Acoustic Radiation of Vibrating Plate

80%

Kozień M., Wiciak J.

Acta Physica Polonica A

|

2009

|

vol. 116

|

issue 3

348-350

EN

The study is a next part of earlier works by the authors, and explores how does the sequence of activated actuators and the level of applied voltage affect the radiated acoustic energy. The analysis uses the finite element method for structural vibrations and combination of the finite element and the intensity hybrid method to assess the level of sound radiation. The vibrating element is a steel plate with glued on actuators, supported on one edge and excited by a harmonically variable, concentrated load with a constant amplitude value.

9

Passive Structural Acoustic Control of the Smart Plate - FEM Simulation

80%

Kozień M., Wiciak J.

|

issue 6

1186-1188

EN

Finite element simulations of passive damped system applied to the simply-supported excited squared steel plate, is the aim of the analysis. The full mechanical, piezoelectric, electric and acoustic field coupling is analysed in Ansys Package. As the result the acoustic pressure radiated by plate is analysed. The results show possibility of application of the discussed method to reduction of the sound pressure level in realistic engineering structures.

10

Rotational Spectrum of the Most Abundant Isotopomers of the Van der Waals Dimer N_2···HBr

70%

Kisiel Z., Pietrewicz B., Pszczółkowski L.

Acta Physica Polonica A

|

2002

|

vol. 101

|

issue 2

231-242

EN

The rotational spectrum of the two most abundant isotopomers of the weakly bound dimer between dinitrogen and hydrogen bromide, ^{14}N_2···H^{79}Br and ^{14}N_2···H^{81}Br, has been measured for the first time. The three lowest J transitions, at frequencies from 2 to 8 GHz, have been studied at conditions of supersonic expansion. The complicated hyperfine splitting structure arising from the three non-equivalent quadrupolar nuclei has been assigned and fitted. The resulting spectroscopic constants and the derived molecular quantities are compared with those for other isotopomers, as well as with experimental and calculated results for other linear dimers involving dinitrogen. A revised value for the nuclear quadrupole splitting constant for free nitrogen molecule,ρ(N)=-5.3(1) MHz, is also derived.

11

Calculations of Molecular Structures and Processes Important for Hydrogen Behaviour in the Li-Amide/Imide System

70%

Ivanović N., Radisavljević I., Novaković N., Manasijević M., Colognesi D.

Acta Physica Polonica A

|

2011

|

vol. 120

|

issue 2

242-245

EN

Lithium amide (LiNH_{2}) and imide (Li_{2}NH) have recently attracted much attention as part of the Li-H-N system suitable for hydrogen (H) storage applications. However, the ground-state imide structure is still unknown with at least six candidate structures, with ground state energies all very close to one another. In order to discover possible pathways for the imide-amide-imide transformations during the hydrogen absorption/desorption cycles, we have examined the molecular structures involved (along with their changes during these processes) using ab-initio calculations based on the linear combination of atomic orbitals (LCAO). In addition, the influence of Li substitution by some other elements of interest on the system behaviour was investigated. These analyses were complemented by density functional theory (DFT) calculations of several crystal structures appearing in the processes. In this way a thorough insight into the structures and the processes taking place at atomic level is attained, providing a starting point for understanding these complicated systems, and the mechanisms governing their transformations.

12

Observation and Properties of the van der Waals Dimer Ar· ··HCCCN Produced in Electrical Discharge

70%

Desyatnyk O., Kosarzewski J., Kisiel Z.

Acta Physica Polonica A

|

2003

|

vol. 104

|

issue 5

415-424

EN

The weakly bound van der Waals dimer between a molecule of cyanoacetylene and an argon atom was observed by rotational spectroscopy of supersonic expansion. Cyanoacetylene was generated in situ from vinyl cyanide precursor by means of a high voltage discharge just downstream of the expansion nozzle. Both ^bR- and ^bQ-type rotational transitions were measured and rotational, centrifugal distortion, and nuclear quadrupole splitting constants were determined. Analysis of the data shows that ground state geometry of the dimer is characterised by R_{cm}=3.65Å andθ=94.9º, with the Ar atom shifted from the position above the cyanoacetylene centre of mass in the direction of the CN group.

Refine search results

Evaluation of Rotational g-Factor of ^{6}Li^{1}H and ^{6}Li^{2}H from Pure Rotational and Vibration-Rotational Spectra of LiH X^{1}Σ^{+}

Quantitative Analysis of Vibration-Rotational Spectra of Diatomic Molecules with (v,j)-Dependent Dynamical Reference Conformation. Application to LiH X^{1}Σ^{+}

A Study on Possibility to Apply Piezoelectric Actuators for Active Reduction of Torsional Beams Vibrations

Comparison of Active and Passive Damping of Plate Vibration by Piezoelectric Actuators - FEM Simulation

Simulation of Application of FGM Piezoelectric Actuators for Active Reduction of Beam Vibrations

Reanalysis of the Ångström System (B^1 Σ^{+} - A^1Π) in the ^{13}C^{16}O Isotopic Molecule

Stable and Unstable Rovibrational States of a Molecule

Choosing of Optimal Voltage Amplitude of Four Pairs Square Piezoelectric Elements for Minimization οf Acoustic Radiation of Vibrating Plate

Passive Structural Acoustic Control of the Smart Plate - FEM Simulation

Rotational Spectrum of the Most Abundant Isotopomers of the Van der Waals Dimer N_2···HBr

Calculations of Molecular Structures and Processes Important for Hydrogen Behaviour in the Li-Amide/Imide System

Observation and Properties of the van der Waals Dimer Ar· ··HCCCN Produced in Electrical Discharge