scholarly journals Contributions to the Interpretation of Mass Spectrum of Hexaethoxydisiloxane Linked scans and M+1, M+2 isotopic effects

2019 ◽  
Vol 70 (8) ◽  
pp. 2934-2939
Author(s):  
Virgil Badescu
Keyword(s):  
Mass Spectrum ◽  
Ionization Chamber ◽  
Quantum Calculations ◽  
Electronic Impact ◽  
Primary Fragmentation ◽  
Fragmentation Reactions ◽  
The Masses ◽  
Double Focusing ◽  
Primary Ions ◽  
Isotopic Effects

The aim of this article is the study of the fragmentation reactions of hexaethoxydisiloxane initiated by electronic impact in the ionization chamber of a double focusing mass spectrometer. The initiation center of fragmentation reactions is established by quantum calculations. The daughter ions of hexaethoxydisiloxane molecular ion are obtained by linked scan B/E. The primary fragmentation ions with the masses 341, 297, 296 and 269 were obtained experimentally by B/E linked scan by radical induced fragmentation reactions. The eliminations of neutral fragments such as hydrogen, acetaldehyde, ethylene and water from the primary ions and the obtained ions by consecutive elimination reactions were emphasized experimentally by the B/E(1-E)1/2 linked scan by charge induced reactions.

scholarly journals Contributions to the Interpretation of Mass Spectrum of Octaethoxycyclotetrasiloxane: Linked Scansand Isotopic Effects

Proceedings ◽  
2019 ◽  
Vol 29 (1) ◽  
pp. 103
Author(s):  
Virgil Badescu
Keyword(s):  
Mass Spectrum ◽  
Mass Spectrometer ◽  
Ionization Chamber ◽  
Electronic Impact ◽  
Fragmentation Reactions ◽  
Double Focusing ◽  
Isotopic Effects

The aim of this article is the study of the fragmentation reactions of octaethoxycyclotetrasiloxane (CTET) initiated by electronic impact in the ionization chamber of a double focusing mass spectrometer. [...]

Contributions to the Interpretation of Mass Spectrum of Tetraethoxysilane (TEOS). III. Accurate mass and M+1, M+2 isotopic effect measurements

2020 ◽  
Vol 71 (2) ◽  
pp. 209-217
Author(s):  
Virgil Badescu
Keyword(s):  
Mass Spectrometry ◽  
Mass Spectrum ◽  
High Resolution ◽  
Sol Gel ◽  
Isotopic Effect ◽  
Sol Gel Process ◽  
Primary Fragmentation ◽  
Fragmentation Reactions ◽  
Primary Ions ◽  
Isotopic Effects

The aim of this article in continuation of Parts I [1] and II [2] is the interpretation of the TEOS mass spectrum as a precursor in the sol-gel process. In Part I [1] the primary fragmentation ions at masses 207, 193, 179 and 163 were obtained experimentally by B/E linked scan by radical induced fragmentation reactions. In Part II [2] eliminations of neutral fragments from the primary ions and the obtained ions by consecutive elimination reactions were evidenced experimentally by the B/E and B/E(1-E)1/2 linked scans. In this third and final Part of interpretation of the TEOS mass spectrum, the separation of ions by mass spectrometry at high resolutions of 5000 and 6600, relative to standard resolution 1000, and measurements of the M+1 and M+2 isotopic effects at the resolution of 5000 are presented. The separation of the ions with nominal mass 105 at high resolution is detailed.

scholarly journals Contributions to the Interpretation of Mass Spectra of the TEOS Methoxy-Transesters. Linked Scans, Accurate Mass Measurements and M+1, M+2 Isotopic Effects

2020 ◽  
Vol 71 (8) ◽  
pp. 39-54
Author(s):  
Virgil Badescu
Keyword(s):  
Mass Spectra ◽  
Structural Formula ◽  
Molecular Ions ◽  
Accurate Mass ◽  
Mass Measurements ◽  
Electronic Impact ◽  
Accurate Mass Measurements ◽  
Fragmentation Reactions ◽  
Double Focusing ◽  
Isotopic Effects

The aim of this article is the study of the fragmentation reactions of the methoxy-transesters of tetraethoxysilane (TEOS), with structural formula (CH3O)x(C2H5O)ySi, initiated by electronic impact in the ionization chamber of a double focusing mass spectrometer. The initiation centers of fragmentation reactions for the neutral and ionized TEOS methoxy-transesters were established by quantum calculations of net atomic charges. The ions of the mass spectra of the TEOS methoxy-transesters were obtained experimentally by the B/E and B/E(1-E)1/2 linked scans. Thus, there can be written the fragmentation pathways for the primary events by B/E linked scan (cleavage of methoxy and ethoxy groups) and eliminations of neutral molecules (acetaldehyde, ethylene, formaldehyde, molecular hydrogen) by B/E(1-E)1/2 linked scan. Accurate mass measurements at high resolution (5000), double bond equivalent (DBE) for the molecular ions and fragmentation ions of the TEOS methoxy-transesters and M+1, M+2 isotopic effects were used to confirm their identification. The reaction pathways and accurate mass in mass spectrum of dimethoxydiethoxysilane (TR2M) are detailed.

CONCURRENT ION–MOLECULE REACTIONS LEADING TO THE SAME PRODUCTION

1962 ◽  
Vol 40 (10) ◽  
pp. 1986-1996 ◽  
Author(s):  
A. G. Harrison ◽  
J. M. S. Tait
Keyword(s):  
High Pressure ◽  
Mass Spectrum ◽  
Cross Sections ◽  
Reaction Cross ◽  
Ion Molecule Reactions ◽  
Secondary Ions ◽  
Primary Ions ◽  
Reaction Cross Sections

Seven of the major secondary ions in the high-pressure mass spectrum of cyclopropane have been studied. A method has been developed for studying concurrent ion–molecule reactions and it has been shown that four of the secondary ions are the products of more than one reaction. Cross sections for the separate reactions are reported. The appearance potentials of the major primary ions in the mass spectrum of cyclopropane have been measured.

scholarly journals The Spin-Spin Interaction Mechanism between Quarks and Its Impact on the Mass Spectrum of Mesons

2019 ◽  
Author(s):  
Engel Roza
Keyword(s):  
Dipole Moment ◽  
Mass Spectrum ◽  
Interaction Mechanism ◽  
Quantum Mechanical ◽  
Spin Interaction ◽  
Spatial Description ◽  
Mechanical Oscillator ◽  
Common Root ◽  
The Masses ◽  
Quark Flavors

A structure-based view on mesons is given, based upon the concept of an archetype quark, described as a pointlike source producing an energy flux, the spatial description of which is derived from Dirac’s second dipole moment. This enables to conceive the archetype meson (pion) as a structure that behaves as a one-body anharmonic quantum mechanical oscillator. All mesons appear being excitations of the archetype, thereby allowing a calculation of the mass spectrum without the use of empirical parameters for the masses of the quark flavors. This includes a physically comprehensible analysis of the spin-spin interaction between quarks. It also provides a solution for the eta-etaprime puzzle. Next to this, it is shown that quite some particles that are presently regarded as elementary, have a common root and can be traced back to a few archetypes only.

EVIDENCE FOR AN (n, α) REACTION INDUCED IN O17 BY THERMAL NEUTRONS

1947 ◽  
Vol 25a (2) ◽  
pp. 77-87 ◽  
Author(s):  
A. N. May ◽  
E. P. Hincks
Keyword(s):  
Cross Section ◽  
Neutron Capture ◽  
Ionization Chamber ◽  
Capture Cross Section ◽  
Thermal Neutrons ◽  
Thermal Neutron Capture ◽  
Energy Bands ◽  
A Value ◽  
Neutron Reactions ◽  
The Masses

It can be shown from the masses involved that the reaction O17 (n, α) C14 should be exothermic by 1.72 Mev., and should therefore occur with thermal neutrons. As an attempt to detect the reaction an investigation was made of the pulse spectrum produced when an ionization chamber containing oxygen was placed in a flux of thermal neutrons. The pulses were amplified and then counted in a series of energy bands by means of a kicksorter. Two oxygen samples were compared, one being enriched (three times normal), and the other impoverished (0.5 times normal), in O17. Differences between runs with these two gases showed a considerable number of pulses between 1 and 2 Mev., with a maximum at 1.4 Mev. Reasons are given for assigning these pulses to the above reaction, including considerations of the possibility that other exothermic neutron reactions occur. By comparing the number of pulses with the number produced by N14 (n, p) C14 when the chamber contained air, a value of (1.9 ± 0.5) × 10−28 cm.2 for the cross-section for the O17 (n, α) C14 reaction in ordinary oxygen was deduced. This gives a cross-section of (0.46 ± 0.11) × 10−24 cm.2 per atom of the pure isotope O17. The effect measured is about 20% of the total thermal neutron capture cross-section that has been reported for ordinary oxygen.

SPECTROSCOPY OF LIGHT HADRONS ON ANISOTROPIC LATTICES

2006 ◽  
Vol 21 (26) ◽  
pp. 5253-5274
Author(s):  
FRANK X. LEE
Keyword(s):  
Mass Spectrum ◽  
Lattice Qcd ◽  
Excited States ◽  
Ground State ◽  
Quark Mass ◽  
Tree Level ◽  
Mass Dependence ◽  
Anisotropic Lattices ◽  
Quark Mass Dependence ◽  
The Masses

The mass spectrum of spin-1/2 baryons in both parity channels is computed using the methods of lattice QCD in the quenched approximation. An anisotropic action with anisotropy as/at = 3 is employed, using tree-level coefficients with tadpole improvement. Clear splittings from the nucleon ground state are observed with smeared operators and 500 configurations. Methods for extracting the first excited states are investigated. Using the quark mass dependence of the masses, qualitative comparisons are made with previous calculations and experiment.

Isotopic Effects in Single Filament Thermal Ion Sources

1964 ◽  
Vol 19 (6) ◽  
pp. 736-740 ◽  
Author(s):  
A. Eberhardt ◽  
R. Delwiche ◽  
J. Geiss
Keyword(s):  
Isotopic Ratio ◽  
Ion Sources ◽  
Time Dependent ◽  
Isotopic Ratios ◽  
Square Root ◽  
Single Filament ◽  
Fractionation Factor ◽  
Rayleigh Distillation ◽  
The Masses ◽  
Isotopic Effects

Isotopic effects occuring during the evaporation of microgram quantities of chemically pure rubidium, potassium and lithium compounds are studied. The measured isotopic ratios show a time dependent variation corresponding to a RAYLEIGH distillation. The fractionation factor is equal to the square root of the ratio of the masses. The highest observed enrichments are 45% for lithium, 10% for potassium and 5% for rubidium. The measured isotopic ratio depends also on the filament material and on the chemical composition of the sample. The discriminations are of the order of the square root of the ratio of the masses.

scholarly journals Towards a complete mass spectrum of type-IIB flux vacua at large complex structure

2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
Jose J. Blanco-Pillado ◽  
Kepa Sousa ◽  
Mikel A. Urkiola ◽  
Jeremy M. Wachter
Keyword(s):  
Mass Spectrum ◽  
Complex Structure ◽  
Effective Field ◽  
Effective Theory ◽  
Tree Level ◽  
Large Complex ◽  
Common Strategy ◽  
Complete Computation ◽  
The Masses ◽  
Large Complex Structure

Abstract The large number of moduli fields arising in a generic string theory compactification makes a complete computation of the low energy effective theory infeasible. A common strategy to solve this problem is to consider Calabi-Yau manifolds with discrete symmetries, which effectively reduce the number of moduli and make the computation of the truncated Effective Field Theory possible. In this approach, however, the couplings (e.g., the masses) of the truncated fields are left undetermined. In the present paper we discuss the tree-level mass spectrum of type-IIB flux compactifications at Large Complex Structure, focusing on models with a reduced one-dimensional complex structure sector. We compute the tree-level spectrum for the dilaton and complex structure moduli, including the truncated fields, which can be expressed entirely in terms of the known couplings of the reduced theory. We show that the masses of this set of fields are naturally heavy at vacua consistent with the KKLT construction, and we discuss other phenomenologically interesting scenarios where the spectrum involves fields much lighter than the gravitino. We also derive the probability distribution for the masses on the ensemble of flux vacua, and show that it exhibits universal features independent of the details of the compactification. We check our results on a large sample of flux vacua constructed in an orientifold of the Calabi-Yau $$ {\mathbbm{W}\mathrm{\mathbb{P}}}_{\left[1,1,1,1,4\right]}^4 $$ W ℙ 1 1 1 1 4 4 . Finally, we also discuss the conditions under which the spectrum derived here could arise in more general compactifications.

scholarly journals The Spin-Spin Interaction Mechanism between Quarks and Its Impact on the Mass Spectrum of Mesons

2019 ◽  
Author(s):  
Engel Roza
Keyword(s):  
Mass Spectrum ◽  
Interaction Mechanism ◽  
Higgs Field ◽  
Quantum Mechanical ◽  
Spin Interaction ◽  
Spatial Description ◽  
Mechanical Oscillator ◽  
Common Root ◽  
The Masses ◽  
Quark Flavors

A structure-based view on mesons is given, based upon the concept of an archetype quark, described as a pointlike source producing an energy flux, the spatial description of which is derived from the functional description of the Higgs field. This enables to conceive the archetype meson (pion) as a structure that behaves as a one-body anharmonic quantum mechanical oscillator. All mesons appear being excitations of the archetype, thereby allowing a calculation of the mass spectrum without the use of empirical parameters for the masses of the quark flavors. This includes a physically comprehensible analysis of the spin-spin interaction between quarks. It also provides a solution for the eta-etaprime puzzle. Next to this, it is shown that quite some particles that are presently regarded as elementary, have a common root and can be traced back to a few archetypes only.

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