Analytical atomic spectrometry seems to be suffering a sort of ‘identity crisis’ at the sunset of this millennium. The field has undergone profound changes and the rate of change has increased dramatically in the last decade. For many years the main goal of analytical atomic spectrometry was to provide atomic/elemental information on the composition of matter via the development of spectrochemi...

It has been reported recently that classical, isothermal-isobaric molecular dynamics (NTP MD) simulations at a time step of 1.00 fs of the standard-mass time (Δt=1.00 fssmt) and a temperature of ≤340 K using uniformly reduced atomic masses by tenfold offers better configurational sampling than standard-mass NTP MD simulations at the same time step. However, it has long been reported that atomic...

The Avogadro constant has long been defined as the number of molecules of a substance in a gram molecular weight [1]. In a modern parlance, it is a fundamental physical constant representing the number of entities comprising 1 mol. It is clear that any modification to the definition of macroscopic (kilogram) or microscopic mass scales (atomic mass) will affect the numerical value of the Avogadr...

Informally, a chemical reaction network is “atomic” if each reaction may be interpreted as the rearrangement of indivisible units of matter. There are several reasonable definitions formalizing this idea. We investigate the computational complexity of deciding whether a given network is atomic according to each of these definitions. Our first definition, primitive atomic, which requires each re...

The total mass attenuation coefficients (μ t ) (cm(2)/g) and atomic, molecular, and electronic effective cross sections have been calculated for nonessential amino acids that contain H, C, N, and O such as tyrosine, aspartate, glutamine, alanine, asparagine, aspartic acid, cysteine, and glycine in the wide energy region 0.015-15 MeV. The variations with energy of total mass attenuation coeffici...

Mass energy absorption coefficients and effective atomic numbers for photon energy absorption, ZPEAeff have been calculated in the energy range from 1 keV to 20 MeV for human tissues, Adipose Tissue, Blood Whole, Bone Cortical, Brain Grey/White Matter, Breast Tissue, Eye Lens, Lung Tissue, Muscle Skeletal, Ovary, Testis, Soft Tissue. Mass energy absorption coefficients and effective atomic numb...