Nambu's Nobel Prize,the meson and the mass of visible matter

The electroweak Higgs boson has been discovered in ongoing experiments at the LHC, leading to a mass of this particle of 126 GeV. This Higgs boson mediates the generation of mass for elementary particles, including the mass of elementary (current) quarks. These current‐quark masses leave 98% of the mass of the atom unexplained. This large fraction is mediated by strong interaction, where instead of the Higgs boson the σ meson is the mediating particle. Though already introduced in 1957 by Schwinger, the σ meson has been integrated out in many theories of hadron properties because it had not been observed and was doubted to exist. With the observation of the σ meson in recent experiments on Compton scattering by the nucleon at MAMI (Mainz) it has become timely to review the status of experimental and theoretical researches on this topic.     

Synthesis, crystal structure, spectral and thermal properties of 4-dimethylaminopyridinium salicylate monohydrate

4-dimethylaminopyridinium salicylate monohydrate (DMAPSA) was synthesized and its crystal structure was determined using single crystal X-ray diffraction analysis. From the crystal structure analysis it can be inferred that the crystal belongs to monoclinic system with space group of P2₁/n. Investigation has been carried out to assign the vibrational frequencies of the grown crystals by FTIR spectral studies. ¹H and ¹³C FT–NMR has been recorded to elucidate the molecular structure. The molecular mass of DMAPSA has been measured using mass spectroscopic analysis. The thermal stability and thermal decomposition of DMAPSA have been investigated by means of thermogravimetric analysis and differential thermal analysis. The melting point of crystal was observed as 172 °C by melting point apparatus. Fluorescence spectra were taken for the excitation wavelength of 240 nm.     

De Haas-van Alphen study of the hexaborides of La,Ce, Pr,and Nd; First results

The de Haas-van Alphen effect has been observed in the hexaborides of La, Ce, Pr and Nd with the direction of the field parallel to [100]. The frequencies for the heavier rare-earth compounds are close to those for LaB₆; large values for the mass compared to the ones in LaB₆ and strong anisotropy of scattering has been observed.     

Exploration of pulse timing for multiple laser hits within a combined heat transfer, phase change, and gas dynamics model for laser ablation

Laser ablation involves heat transfer, phase changes and/or chemical reactions, and gas dynamics. All three of these processes are tightly coupled with each other. A model has previously been developed to simulate the nanosecond scale laser ablation of carbon. This model has been extended to accommodate longer term simulations and multiple laser pulses. The effects of varying the timing of a second laser pulse by tens of nanoseconds are explored. It is shown that by changing this interval one can control the total mass ablated and the mass transfer rate.     

Mass excesses of 79As, 81As,and 80Ge

Accurate mass measurements for the nuclides ⁷⁹As, ⁸¹As, and ⁸⁰Ge have been measured. Good agreement has been found for ⁷⁹As and ⁸¹As with the Garvey-Kelson transverse mass relation and with several mass model predictions. The agreement for ⁸⁰Ge is not as satisfactory and presents a challenge for understanding mass values far off the line of stability.     

Precision mass measurements of neutron-rich Y, Nb, Mo, Tc, Ru, Rh, and Pd isotopes

Direct mass measurements with typical uncertainties of 1-10keV have been performed for the first time for ten neutron-rich isotopes ^{102, 103}Y , ¹⁰⁸Nb , ¹¹¹Mo , ^{113, 114}Tc , ¹¹⁶Ru , ¹¹⁹Rh , and ^{121, 122}Pd . The obtained mass data compared with the 2003 atomic-mass evaluation shows systematic overestimation of binding energies far from stability. The relationship between two-neutron separation energies, nuclear structure and shape changes has been investigated by comparing the experimental data with a theoretical calculation based on the Hartree-Fock-Bogoliubov approximation using modern energy density functionals.     

Photon wavelength, information transport speed, and mass. An information mechanics perspective

In Newton's mechanics, Maxwell's electromagnetism, Einstein's relativistic mechanics, quantum mechanics, and Kantor's information mechanics (IM), the speed of light in vacuumc has been treated as independent of wavelength. However, in IM, the transport of information by means of an electromagnetic signal appears to offer a perspective for reconsidering photon information transport speed, extending the concept of (rest) mass to treat the photon as having a mass of 1 bit.     

Molecular Dynamics Study of gases H2,D2 and T2

The classical Molecular dynamics simulation has been used to study the equation of state of gas H2,D2 and T2.It has also been investigated that the isotope mass affects on the accuracy of equation of state.Our calculated Iesults show that the classical effect is principal and the isotope mass effects on the equation of state are obvious for the much light gases.At the same time,some useful theoretical data of equation of state for these gases have been provided.It is found that the classical simulation is still effective to the quantum gas.However,the quantum mechanics simulation and the improvement of intermolecular interaction potential are necessary if more accurate computational results are expected.     

Mass,matter, and energy. A relativistic approach

The debate concerning the relations between matter and motion has the same age as philosophy itself. In modern times this problem was transformed into the one concerning the relations between mass and energy. Newton identified mass with matter. Classical thermodynamics brought this conception to its logical conclusion, establishing an ontic dichotomy between mass-matter and energy. On the basis of this pre-relativistic conception, Einstein's famous equation has been interpreted as a relation of equivalence between mass-matter and energy. Nevertheless, if we reject this epistemologically illegitimate identification, it is possible to elaborate a unitary conception of matter, which at the same time is an argument for the unity between matter and motion. In particular, the classical antithesis between matter and field becomes obsolete in the frame of the proposed interpretation.     

The Compensation of Large Ion Energy Spread by Multigap Grid Reflectors of Time-of-Flight Mass Spectrometers: Cases of Catastrophes A4, A5, A6, and A7

Technical Physics - The problem of compensation of the initial energy spread of ions by multigap reflectors of time-of-flight mass spectrometers with grids has been considered. Cases of...     

Effective masses of electrons and heavy holes in InAs,InSb, GaSb,GaAs and some of their ternary compounds

A survey is carried out for both electron and heavy-hole effective masses in InAs, InSb, GaAs, GaSb and some of their ternary compounds. Our computations are based on the pseudopotential method. To make allowance for the chemical disorder, the virtual crystal approximation is used, including a correction to the alloy potential. The agreement between our theoretical results and the experiment is very satisfying. A non-linearity dependence of the electron effective mass on the molar fraction has been shown for the ternary alloys under consideration, which indicates the alloying effect. This non-linearity disappears in the case of the heavy-hole effective mass for GaInSb.     

Adhesive strength, superhardness, and the phase and elemental compositions of nanostructured coatings based on Ti-Hf-Si-N

New superhard coatings based on Ti-Hf-Si-N with good physical and mechanical properties have been fabricated. A comparative analysis of the physical, mechanical, and tribomechanical characteristics of the coatings has been performed. The values of hardness, modulus of elasticity, elastic recovery, adhesive strength, friction coefficient, and wear rate of the coatings have been determined and calculated. The specific features of deformation and fracture of the coatings deposited on a steel substrate during the adhesion tests have been described. It has been shown that the parameters measured during scratching make it possible to distinguish the threshold values of the critical load, which lead to different (cohesive and adhesive) types of failure of the coatings during tribological tests. The stoichiometry for different series of samples with Ti-Hf-Si-N coatings has been determined using Rutherford backscattering, secondary ion mass spectrometry, and energy dispersive microanalysis.     

Lipid hydroperoxides in nutrition,health, and diseases

Research on lipid peroxidation in food degradation, oil and fat nutrition, and age-related diseases has gained significant international attention for the view of improvement of societal health and longevity. In order to promote basic studies on these topics, a chemiluminescence detection-high performance liquid chromatography instrument using a high-sensitivity single photon counter as a detector was developed. This instrument enabled us to selectively detect and quantify lipid hydroperoxides, a primary product of lipid peroxidation reactions, as hydroperoxide groups at the lipid class level. Furthermore, an analytical method using liquid chromatography–tandem mass spectrometry has been established to discriminate the position and stereoisomerization of hydroperoxide groups in lipid hydroperoxides. Using these two methods, the reaction mechanisms of lipid peroxidation in food and in the body have been confirmed.     

Precise atomic mass difference determinations between some stable isotopes of Ge,As and Se

The 1 m radius, high-resolution mass spectrometer at the University of Manitoba (“Manitoba II”) has been used to determine 11 atomic mass differences between some stable isotopes of Ge, As and Se. These values are of greater accuracy and precision than existing data. Their consistency has been checked by a major least-squares adjustment involving relevant data in the region. Results include improved S_2n values for several nuclides and the energies available for the ββ decays of ⁷⁶Ge and ⁷⁴Se, respectively.     

Mass excesses of60, 62Fe,68Ni,69Cu,74Zn,73, 75Ga

Accurate, confirmed mass excess values have been determined for the nuclei^{60, 62}Fe,⁶⁸Ni,⁶⁹Cu, and^{73, 75}Ga by theQ-value method. The mass of⁷⁴Zn requires further study. Good agreement was found between experimentally determined mass values and those from mass model predictions.     

Mass Spectrometry,Review of the Basics: Electrospray,MALDI, and Commonly Used Mass Analyzers

Abstract

Mass spectrometry (MS) has progressed to become a powerful analytical tool for both quantitative and qualitative applications. The first mass spectrometer was constructed in 1912 and since then it has developed from only analyzing small inorganic molecules to biological macromolecules, practically with no mass limitations. Proteomics research, in particular, increasingly depends on MS technologies. The ability of mass spectrometry analyzing proteins and other biological extracts is due to the advances gained through the development of soft ionization techniques such as electrospray ionization (ESI) and matrix-assisted laser desorption ionization (MALDI) that can transform biomolecules into ions. ESI can efficiently be interfaced with separation techniques enhancing its role in the life and health sciences. MALDI, however, has the advantage of producing singly charges ions of peptides and proteins, minimizing spectral complexity. Regardless of the ionization source, the sensitivity of a mass spectrometer is related to the mass analyzer where ion separation occurs. Both quadrupole and time of flight (ToF) mass analyzers are commonly used and they can be configured together as QToF tandem mass spectrometric instruments. Tandem mass spectrometry (MS/MS), as the name indicates, is the result of performing two or more sequential separations of ions usually coupling two or more mass analyzers. Coupling a quadrupole and time of flight resulted in the production of high-resolution mass spectrometers (i.e., Q-ToF). This article will historically introduce mass spectrometry and summarizes the advantages and disadvantages of ESI and MALDI along with quadrupole and ToF mass analyzers, including the technical marriage between the two analyzers. This article is educational in nature and intended for graduate students and senior biochemistry students as well as chemists and biochemists who are not familiar with mass spectrometry and would like to learn the basics; it is not intended for mass spectrometry experts.     

VIBRATION OF PLATES IN DIFFERENT SITUATIONS USING A HIGH-PRECISION SHEAR DEFORMABLE ELEMENT

A high-precision thick plate element proposed by the last author of this paper has been applied to free vibration analysis of plates to study its performance. The element has a triangular shape and it has three nodes at its corners, three mid-side nodes on each side and four nodes within the element. The transverse displacement and rotations of the normal have been taken as independent field variables and they have been approximated with polynomials of different orders. This has not only helped to include the effect of shear deformation but also made the element free from locking in shear. Initially, the number of degrees of freedom of the element is 35, which is reduced to 30 by eliminating the degrees of freedom of the internal nodes. This has been done through static condensation. To facilitate the condensation process, efficient mass lumping schemes have been recommended to form the mass matrix having zero mass for the internal nodes. Recommendation has also been made for the inclusion of mass for rotary inertia in a lumped mass matrix. Numerical examples of plates having different shapes and boundary conditions have been solved by this element. Examples of plates having internal cutout and concentrated mass have also been studied. The results obtained in all the cases have been compared with the published results to show the accuracy and range of applicability of the present element.     

Search for lepton flavor violating decays tau(+/-) --> l(+/-)pi0, l(+/-)eta, l(+/-)eta'

A search for lepton flavor violating decays of the tau lepton to a lighter mass lepton and a pseudoscalar meson has been performed using 339 fb;{-1} of e;{+}e;{-} annihilation data collected at a center-of-mass energy near 10.58 GeV by the BABAR detector at the SLAC PEP-II storage ring. No evidence of a signal has been found, and upper limits on the branching fractions are set at the 10;{-7} level.     

Problems, prospects, and alternatives for semiconductor single crystal growth in space

Experimental results for growing semiconductor single crystals under real microgravitation conditions aboard spacecraft have been analyzed. The causes for the formation of dopant distribution micro- and macroinhomogeneities in crystals have been studied. It has been shown that it is necessary to provide diffusion heat and mass transfer conditions in a melt to achieve a high homogeneity of properties in grown crystals. These conditions and expected optimal parameters of crystals can be obtained in the absence of thermogravitational convection, when a free surface of the melt is eliminated, and also under conditions of minimizing external quasi-static effects on the melt causing forced convective flows in them and, correspondingly, inhomogeneity of composition and properties for grown crystals due to the increasing gravitational sensibility of melts under microgravitation conditions.     

X‐ray fluorescence determination of Cs,Ba, La,Ce, Nd,and Ta concentrations in rocks of various composition

The technique has been developed for the quantification of small tantalum, cesium, barium, lanthanum, cerium, and neodymium concentration in rocks with X‐ray wavelength dispersive spectrometer S8 TIGER (Bruker AXS, Germany). The optimum conditions have been chosen for registration of the analyzed elements characteristic radiation and background positions. To determine the concentrations of analyzed elements accurately, the contribution of overlapping lines to the experimental intensities of the analytical lines has been taken into account. The sample of mass about 1.2 g has been pressed into pellet by the hydraulic press. Metrological studies showed that the accuracy in the determination of the concentration of analyzed elements for the developed technique meets the requirements for methods of III accuracy class. The Ta detection limits calculated for TaL_β1‐analytical and CsL_α1‐analytical lines were 2.6 and 3.4 ppm, respectively. The detection limit of Ba, La, Ce, and Nd was (in ppm), respectively, 4.3, 2.7, 5.8, and 4.7. The metrological characteristics of the previously developed and adapted techniques were compared. Ta concentration in granite pegmatite samples has been quantified. The samples of the highest tantalum content have been investigated additionally by powder diffraction and X‐ray microprobe analysis. The X‐ray diffraction method turned out to be insensitive to the detection of mineral phase of tantalum niobates, while micro‐XRF allowed detecting its presence in tourmaline grains. Copyright © 2017 John Wiley & Sons, Ltd.