The dynamics of oligomer desorption from surfaces have been studied by measuring the desorption kinetics of a set of n-alkanes from the surface of single crystalline graphite. Desorption rates were measured using a set of 21 monodispersed n-alkanes (CNH2N12,5<N<60) each adsorbed at coverages in the range ,0.1 to .1 monolayers. Desorption is observed to be a first-order process with a desorption...

1. Protection against desiccation and chemical communication are two fundamental functions of cuticular hydrocarbons (CHCs) in insects. In the parasitoid jewel wasp Nasonia vitripennis (Walker), characterised by a cosmopolitan distribution through largely different environments, CHCs function as universally recognised female sex pheromones. However, CHC uniformity basis for sexual recognition m...

the composition of the essential oil from the stalks and flowers of rheum ribes l., growing in iran, were extracted by hydrodistillation and analyzed by gc-ms. thirty constituents representing 93.84% of rheum oil were identified.  the oil was found to be rich in hydrocarbons especially long-chain n-alkanes (80.81%). the most abundant components in the oil included tricosane (26.29%), heneicosan...

To achieve a better understanding of Holocene climate change in the monsoon regions of China, we investigated the molecular distributions and carbon and hydrogen isotope compositions (δ13C and δD values) of long-chain n-alkanes in a peat core from the Shiwangutian (SWGT) peatland, south China over the last 9 ka. By comparisons with other climate records, we found that the δ13C values of the lon...

Upon growth on n-hexadecane (C(16)), n-tetracosane (C(24)), and n-hexatriacontane (C(36)), Dietzia sp. strain DQ12-45-1b could produce different glycolipids, phospholipids, and lipopeptides. Interestingly, cultivation with C(36) increased cell surface hydrophobic activity, which attenuated the negative effect of the decline of the emulsification activity. These results suggest that the mechanis...

In this paper, we report on a printable glass-based manufacturing method and new proof-of-concept colorimetric signal readout scheme for dielectric barrier discharge (DBD)-type helium plasma photoionization detector. The sensor consists of millimeter-sized glass chamber manufactured using suspension. Plasma inside the chip is generated custom-built power supply (900 V 83.6 kHz), detector uses ∼...

Extracts of Mandragora autumnalis (mandrake) fruit have been analyzed by GC–MS. One-hundred and thirty-five compounds were identified in extracts obtained from the fruit after removal of the seeds – twentythree n-alkanes, one branched-chain alkane, two cyclohexanes, eight alkenes, two branched-chain alkenes, three alcohols, three aldehydes, six ketones, eight heterocyclic compounds, four thio c...

Ooids are one of the common constituents of ancient carbonate rocks, yet the role that microbial communities may or may not play in their formation remains unresolved. To search for evidence of microbial activity in modern and Holocene ooids, samples collected from intertidal waters, beaches and outcrops in the Bahamas and in Shark Bay in Western Australia were examined for their contents of li...