Search results for "Instrumentation"
showing 10 items of 4914 documents
A Comprehensive Survey on Signcryption Security Mechanisms in Wireless Body Area Networks
2022
WBANs (Wireless Body Area Networks) are frequently depicted as a paradigm shift in healthcare from traditional to modern E-Healthcare. The vitals of the patient signs by the sensors are highly sensitive, secret, and vulnerable to numerous adversarial attacks. Since WBANs is a real-world application of the healthcare system, it’s vital to ensure that the data acquired by the WBANs sensors is secure and not accessible to unauthorized parties or security hazards. As a result, effective signcryption security solutions are required for the WBANs’ success and widespread use. Over the last two decades, researchers have proposed a slew of signcryption security solutions to achieve this goal. The la…
The Effect of Paddle Stroke Variables Measured by Trainesense SmartPaddle® on the Velocity of the Kayak
2022
(1) Background: This study aimed to compare key variables of paddle stroke measured by a commercial Trainesense SmartPaddle® against the strain-gauge shaft and investigate how these variables are associated with the velocity of the boat among national-level canoe polo players. (2) Methods: This study involved 14 Finnish national-level canoe polo players. The measurement protocol consisted of three different paddling velocities, which were performed in indoor swimming pools. The velocity of the boat was calculated based on the performance time measured with the laser photocell gate. Canoe polo equipment was used in the study and a SmartPaddle sensor was attached to the paddle blade. A strain…
Water vapour adsorption onto Ca2+ Camp–Berteau montmorillonite and comparison with properties of Na+ sample
2004
Abstract In this paper, we present an analysis of the adsorbed amounts and adsorption heats of water vapour of Ca2+ Camp–Berteau montmorillonite. Measurements were obtained at 298 K using thermogravimetry and calorimetry as a function of relative pressure and the study was completed by the adsorption of nitrogen at 77 K. Experimental data were analysed with BET and t-method theories and compared with those of the Na+ sample. A correlation was shown between models and two domains observed on the calorimetric curves. These domains have been attributed to a multilayer equivalent adsorption. However, the determination of the surface area of clays remains a difficulty. So, the areas of interlaye…
The Ramsey method in high-precision mass spectrometry with Penning traps: Experimental results
2007
The highest precision in direct mass measurements is obtained with Penning trap mass spectrometry. Most experiments use the interconversion of the magnetron and cyclotron motional modes of the stored ion due to excitation by external radiofrequency-quadrupole fields. In this work a new excitation scheme, Ramsey's method of time-separated oscillatory fields, has been successfully tested. It has been shown to reduce significantly the uncertainty in the determination of the cyclotron frequency and thus of the ion mass of interest. The theoretical description of the ion motion excited with Ramsey's method in a Penning trap and subsequently the calculation of the resonance line shapes for differ…
Theoretical study of electronically excited cis- and trans-glyoxal
1997
Abstract The equation-of-motion coupled cluster method for excitation energies in the singles and doubles approximation (EOMEE-CCSD) is applied to an investigation of the structure and harmonic frequencies of planar conformers of glyoxal in their first excited singlet states. For the trans-isomer, agreement between calculated harmonic frequencies and observed fundamentals is generally satisfactory, although the theoretical values are slightly more than 10% too high for the carbonyl stretching modes. Parallel calculations of the corresponding ground state properties allow for an empirical prediction of the excited state frequencies in which calculated differences in normal-mode frequencies a…
A vacuum cell for obtaining clean surfaces on liquid low melting point metals
1997
Abstract Clean oxide film-free surface of liquid gallium was obtained in a sealed vacuum cell with a glass lid for observation. The cell was evacuated to high vacuum (10 -4 Pa) before admission of liquid and sealing. The surface contamination was about 2–5% of the free area and did not exhibit noticeable increase during several months of storing and employing the cell. The cell described allows observation of surface flows, capillary phenomena and crystallization processes under different conditions.
Theory of simultaneous dipole and quadrupole excitation of the ion motion in a Penning trap
2012
Abstract Penning traps confine ions of atoms and molecules as well as other charged particles by a combination of static electric and magnetic fields to the central region of the trap, where these objects can be studied. Most experiments employ pulses of dipolar radio-frequency radiation followed by pulses of quadrupolar radio-frequency radiation to manipulate the motional state of the trapped particles. Instead of a sequential procedure an excitation of the ion motion by the simultaneous application of dipolar and quadrupolar rf-fields is also conceivable. This paper investigates the theory of simultaneous excitation under very general assumptions, with inclusion of possible damping terms.…
Ground and excited state polarizabilities and dipole transition properties of benzene from coupled cluster response theory
1999
Abstract The electronic properties and transition properties have been investigated for the lowest singlet electronic states of benzene using coupled cluster response theory. The polarizabilities have been calculated for the ground state and the 1 1 B 2u , 1 1 B 1u 1 1 E 1u and 2 1 E 1u excited states. The dipole allowed transitions out of these states have also been calculated and discussed in the context of the calculated polarizabilities. Oscillator strengths and the second electronic moments of the charge distributions have been used to characterize and identify qualitative features of the individual states. The performance of coupled cluster singles (CCS), the recently proposed CC2 mod…
The elliptical Penning trap: Experimental investigations and simulations
2008
Abstract The application of an additional azimuthal quadrupolar electrostatic field to a Penning trap leads to a field configuration referred to as an elliptical Penning trap. The resulting changes of the radial ion motions have been investigated experimentally and by use of simulations. The eigenfrequencies, i.e., the magnetron frequency ω ˜ − and the reduced cyclotron frequency ω ˜ + , are found to be shifted with respect to those of the standard Penning trap ω − , ω + , respectively. As the shift of the magnetron frequency ω ˜ − is larger than that of the reduced cyclotron frequency ω ˜ + their sum ω ˜ + + ω ˜ − is also a function of the ellipticity and no longer equal to the cyclotron f…
Damping effects in Penning trap mass spectrometry
2011
Abstract Collisions of ions with residual gas atoms in a Penning trap can have a strong influence on the trajectories of the ions, depending on the atom species and the gas pressure. We report on investigations of damping effects in time-of-flight ion-cyclotron resonance mass spectrometry with the Penning trap mass spectrometers ISOLTRAP at ISOLDE/CERN (Geneva, Switzerland) and SHIPTRAP at GSI (Darmstadt, Germany). The work focuses on the interconversion of the magnetron and cyclotron motional modes, in particular the modification of the resonance profiles for quadrupolar excitation due to the damping effect of the residual gas. Extensive experiments have been performed with standard and Ra…