Atmospheric aerosol particles were collected with a high-volume sampler in a Finnish coniferous forest during the field campaign Quantification of Aerosol Nucleation in the European Boundary Layer (QUEST) in March–April 2003. Four chromatographic techniques were applied to characterise the organic composition of the samples, and to study variations in the concentrations of identified compounds....

Radiocarbon ages of vascular plant wax-derived n-alkanes preserved in well-dated Holocene sediments in an anoxic fjord (Saanich Inlet, Canada) were found to be not only substantially older than the depositional age but increasingly so during the Holocene. Assuming that n-alkanes serve as a proxy for recalcitrant terrigenous organic matter, this indicates that the accumulation of refractory orga...

Reactive oxygen species (ROS) are toxic byproducts of mitochondrial energy production that inflict oxidative stress, a constant barrage of damage to DNA, proteins, lipids, and other biologically important molecules. Oxidative stress has been implicated as a pathologic mechanism in aging and in several diseases. We developed a display of apparent new markers of oxidative stress in human beings, ...

A recent study of temperature-programmed desorption (TPD) measurements of small linear alkane molecules (n-alkanes, with formula C(N)H(2N+2)) from C(0001) deposited on Pt(111) shows a linear relationship of the desorption energy with increasing n-alkane chain length N. We here present a van der Waals density functional study of the desorption barrier energy of the ten smallest n-alkanes (of car...

ABSTRACT: Due to the importance of essential oils and their use in various industries, the essential oils of four types of citrus consisting of orange (C. sinesis), tangerine (C. reticulate), sweet lemon (C. limetta) and sour lemon (C. limon) were extracted and subjected to chemical analysis to identify and evaluate the chemical constituents of the oils. The average essential oils of orange, ta...

Gas chromatography (GC), gas chromatography-mass spectrometry (GC/MS), supercritical fluid chromatography (SFC), elemental analysis, infrared absorption spectroscopy (IR), thermal analysis (TG/DTA), Rock-Eval pyrolysis, as well as viscosity and density analysis revealed that oil sands from Qaidam basin, Qinghai Province of China, are highly concentrated in light components (£C23), with saturate...

The fluorescence decay time of cis-stilbene has been measured in a variety of solvents over a large temperature range. An isoviscosity Arrhenius plot in n-alkanes yields an activation energy of 386±29 em-I. We interpret this result as an upper limit for the cis-stilbene to trans-stilbene barrier in nonpolar solvents. Isoviscosity plots in small alcohols are nonlinear, indicating complicated beh...

We studied the effect of segmented solvent molecules on the free energy of transfer of small molecules from water into alkanes (hexane, heptane, octane, decane, dodecane, tetradecane, and hexadecane). For these alkanes we measured partition coefficients of benzene, 3-methylindole (3MI), 2,3,4,6-tetrachlorophenol (TeCP), and 2,4,6-tribromophenol (TriBP) at 3, 11, 20, 33 [corrected], and 47 degre...

The phase behavior of perfluoro-(n)-alkane + (n)-alkane binary mixtures is of particular interest given their unexpected large positive deviations from Raoult’s law. Binary mixtures of perfluoromethane + (n)-alkanes from methane to heptane are studied here, illustrating the continuous change in phase behavior from type II to type III that these systems exhibit. Some symmetrical systems that dis...

Rubredoxins (Rds) are essential electron transfer components of bacterial membrane-bound alkane hydroxylase systems. Several Rd genes associated with alkane hydroxylase or Rd reductase genes were cloned from gram-positive and gram-negative organisms able to grow on n-alkanes (Alk-Rds). Complementation tests in an Escherichia coli recombinant containing all Pseudomonas putida GPo1 genes necessar...