scholarly journals Delta Baryons, Isospin, and the Need for a New Mendeleev

2012 ◽  
Vol 2012 (02) ◽  
pp. 0218
Author(s):  
Terry Bollinger
Keyword(s):  
Quantum Theory ◽  
Chemical Elements ◽  
Foundations Of Physics

Mendeleev's pragmatic table approach to capturing patterns in the chemical elements allowed it to endure even after quantum theory uncovered the simplicity that created those patterns. While predictively powerful, the Standard Model's early extensive use of mathematical symmetries likely added a level of noise that to this day is hiding, rather than clarifying, the deeper foundations of physics.

Einstein: the classical physicist

2005 ◽  
Vol 59 (3) ◽  
pp. 255-271 ◽  
Author(s):  
J.S Rowlinson
Keyword(s):  
Nineteenth Century ◽  
Twentieth Century ◽  
Quantum Theory ◽  
Statistical Mechanics ◽  
Late Nineteenth Century ◽  
Classical Physics ◽  
Foundations Of Physics ◽  
Late Nineteenth

Einstein is remembered for his contributions to the re-ordering of the foundations of physics in the first years of the twentieth century. Much of his achievement was, however, based on the classical physics of the late nineteenth century and it was his work on statistical mechanics that underlay his first contributions to quantum theory. This essay is an account of an aspect of his achievement that is often overlooked.

scholarly journals Characteristic frequency and atomic number

1917 ◽  
Vol 94 (657) ◽  
pp. 100-111 ◽  
Keyword(s):  
Quantum Theory ◽  
Solid State ◽  
Specific Heat ◽  
Recent Work ◽  
Single Molecule ◽  
Characteristic Frequency ◽  
Chemical Elements ◽  
Temperature Characteristic ◽  
Atomic Heat ◽  
Atomic Frequency

Recent work on the specific heat of chemical elements in the solid state has led to important conclusions with regard to the values of the atomic heat at constant volume. The curves showing the variation of atomic heat with temperature are all of the same form, and any given curve can be transformed into any other merely by altering the scale on which the temperature is plotted. This implies that the atomic heat C v is a function of the temperature T, dependent on a single parameter, the function being the same for different elements. Thus C v = F (Θ/T), where Θ is a certain temperature characteristic of the element in question. According to the quantum theory Θ = βv = hv/k , where v is the characteristic atomic frequency, h is Planck’s constant, 6·558 x 10 -27 , k is the gas constant for a single molecule, 1·372 x 10 -16 .

Nuclear Processes Related to the Ap Stars and the Heaviest Chemical Elements

1976 ◽  
Vol 32 ◽  
pp. 169-182
Author(s):  
B. Kuchowicz
Keyword(s):  
Nuclear Physics ◽  
Nuclear Reactions ◽  
Chemical Elements ◽  
Fission Products ◽  
Abundance Pattern ◽  
Isotopic Shifts ◽  
Processed Material ◽  
R Process ◽  
Ap Stars ◽  
Nuclear Processes

SummaryIsotopic shifts in the lines of the heavy elements in Ap stars, and the characteristic abundance pattern of these elements point to the fact that we are observing mainly the products of rapid neutron capture. The peculiar A stars may be treated as the show windows for the products of a recent r-process in their neighbourhood. This process can be located either in Supernovae exploding in a binary system in which the present Ap stars were secondaries, or in Supernovae exploding in young clusters. Secondary processes, e.g. spontaneous fission or nuclear reactions with highly abundant fission products, may occur further with the r-processed material in the surface of the Ap stars. The role of these stars to the theory of nucleosynthesis and to nuclear physics is emphasized.

Quantitative parallel EELS spectrum imaging developed as a new tool in AEM

1992 ◽  
Vol 50 (2) ◽  
pp. 1202-1203
Author(s):  
Gianluigi Botton ◽  
Gilles L'espérance
Keyword(s):  
Statistical Analysis ◽  
Spatial Resolution ◽  
Personal Computer ◽  
Systematic Study ◽  
Present Author ◽  
Chemical Elements ◽  
Detection Limits ◽  
Research Groups ◽  
Quantitative Performance ◽  
Spectrum Imaging

As interest for parallel EELS spectrum imaging grows in laboratories equipped with commercial spectrometers, different approaches were used in recent years by a few research groups in the development of the technique of spectrum imaging as reported in the literature. Either by controlling, with a personal computer both the microsope and the spectrometer or using more powerful workstations interfaced to conventional multichannel analysers with commercially available programs to control the microscope and the spectrometer, spectrum images can now be obtained. Work on the limits of the technique, in terms of the quantitative performance was reported, however, by the present author where a systematic study of artifacts detection limits, statistical errors as a function of desired spatial resolution and range of chemical elements to be studied in a map was carried out The aim of the present paper is to show an application of quantitative parallel EELS spectrum imaging where statistical analysis is performed at each pixel and interpretation is carried out using criteria established from the statistical analysis and variations in composition are analyzed with the help of information retreived from t/γ maps so that artifacts are avoided.

How SIMS microscopy can be used in medicine

1992 ◽  
Vol 50 (2) ◽  
pp. 1602-1603
Author(s):  
Philippe Fragu
Keyword(s):  
Mass Spectrometry ◽  
Biomedical Applications ◽  
Secondary Ion Mass Spectrometry ◽  
Chemical Elements ◽  
Biological Applications ◽  
The Past ◽  
Potential Source ◽  
Secondary Ion ◽  
Chemical Integrity ◽  
Scientific Endeavour

The identification, localization and quantification of intracellular chemical elements is an area of scientific endeavour which has not ceased to develop over the past 30 years. Secondary Ion Mass Spectrometry (SIMS) microscopy is widely used for elemental localization problems in geochemistry, metallurgy and electronics. Although the first commercial instruments were available in 1968, biological applications have been gradual as investigators have systematically examined the potential source of artefacts inherent in the method and sought to develop strategies for the analysis of soft biological material with a lateral resolution equivalent to that of the light microscope. In 1992, the prospects offered by this technique are even more encouraging as prototypes of new ion probes appear capable of achieving the ultimate goal, namely the quantitative analysis of micron and submicron regions. The purpose of this review is to underline the requirements for biomedical applications of SIMS microscopy.Sample preparation methodology should preserve both the structural and the chemical integrity of the tissue.

X-ray mapping without STEM

1994 ◽  
Vol 52 ◽  
pp. 508-509
Author(s):  
Judith M. Brock ◽  
Max T. Otten
Keyword(s):  
Life Science ◽  
Materials Science ◽  
Chemical Elements ◽  
Full Description ◽  
Scanning System ◽  
Elemental Distribution ◽  
X Ray ◽  
Transmission Electron ◽  
Distribution Of Elements ◽  
Made In

A knowledge of the distribution of chemical elements in a specimen is often highly useful. In materials science specimens features such as grain boundaries and precipitates generally force a certain order on mental distribution, so that a single profile away from the boundary or precipitate gives a full description of all relevant data. No such simplicity can be assumed in life science specimens, where elements can occur various combinations and in different concentrations in tissue. In the latter case a two-dimensional elemental-distribution image is required to describe the material adequately. X-ray mapping provides such of the distribution of elements.The big disadvantage of x-ray mapping hitherto has been one requirement: the transmission electron microscope must have the scanning function. In cases where the STEM functionality – to record scanning images using a variety of STEM detectors – is not used, but only x-ray mapping is intended, a significant investment must still be made in the scanning system: electronics that drive the beam, detectors for generating the scanning images, and monitors for displaying and recording the images.

Quantum theory of light in nonlinear media with dispersion and absorption

1998 ◽  
Vol 45 (2) ◽  
pp. 377-402 ◽  
Author(s):  
EDUARD SCHMIDT , JOHN JEFFERS , STEPHEN M.
Keyword(s):  
Quantum Theory ◽  
Nonlinear Media
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