The trace element compositions of igneous augite preserved in metamorphosed komatiite samples from the lower Komati Formation, Barberton Mountainland, South Africa (3.49 Ga), were analyzed in order to estimate the pre-metamorphic bulk composition of the samples. The chemical effects of metamorphism are evaluated by calculating the trace element (TE) composition of a hypothetical augite in equil...

Monazite grains from Nepal and Vietnam were compositionally analyzed with an electron microprobe and dated (Th–Pb) with an ion microprobe. Five sources of uncertainty explain age distributions from single samples that appear inconsistent with a single population: (1) Pb loss due to diffusion, (2) dissolution/reprecipitation reactions along a retrograde path, (3) analytical uncertainties, (4) an...

The adsorption of Mycobacterium Phlei cells on the surfaces of pyrite and sphalerite was studied as functions of time and pH. The results indicated that a higher amount of cells adsorbing onto pyrite compared with that onto sphalerite under neutral and alkaline conditions, and it was also observed from photographs of scanning electron micrograph. To gain a better insight into the mechanisms of ...

One element of structure that invariably increases the difficulty of a chemical synthesis is the presence in the target molecule of contiguous all-carbon quaternary stereocenters. This Perspective will examine the most useful transformations and strategies devised recently for directly assembling this structural unit.

Which elements are essential for human life? Here we make an element-by-element journey through the periodic table and attempt to assess whether elements are essential or not, and if they are, whether there is a relevant code for them in the human genome. There are many difficulties such as the human biochemistry of several so-called essential elements is not well understood, and it is not clea...

Optical properties (transmission and refractive index) and chemical structure (XPS) of diamond-like coating (DLC) film before and after focused ion beam milling (FIBM) process, were investigated in this paper. It is shown by our FIBM experiment that influence of FIBM on Optical properties and chemical structure of the DLC film is not apparent, especially in near-infra region. The film still ca...

some new remedy, with a scientific name too unwieldy for ordinary use, and too often a value inversely as the length of its chemical formula, it is a novelty to note the reviving reputation of a long-known simple chemical element. Oxygen is not now for the first time associated with medicine. The most important of all the elements was not likely to escape the notice of the inquiring scientific ...

Lutzomyia longipalpis (Diptera: Psychodidae) is the vector of Leishmania chagasi the causative agent of visceral leishmaniasis (VL) in South and Central America, particularly Brazil, where the greatest incidence occurs. The disease is fatal if untreated. Although huge efforts have been made to control VL the incidence is increasing. Vector control remains an important element of disease control...

Introduction: Chemical diffusion of cations and atoms in silicates and metals can promote large isotopic fractionation [1]. An empirical formula relates the diffusion coefficients of two isotopes of an element to their mass ratios through D 1 /D 2 =(m 2 /m 1)

Disadvantages of flame AA are that releasing agents or modifiers are necessary and careful control of the flame stoichiometry is important to overcome chemical interferences [1]. While the atomic absorption technique offers adequate performance, in most cases it is a single element technique and is therefore slow. Analysis of Blood Serum on the Liberty Series II ICP OES with the AxiallyViewed P...