The Experts below are selected from a list of 144 Experts worldwide ranked by ideXlab platform
Santanu K Maiti - One of the best experts on this subject based on the ideXlab platform.
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electron transport through Polycyclic Hydrocarbon molecules a study of shot noise contribution to the power spectrum
Organic Electronics, 2007Co-Authors: Santanu K MaitiAbstract:Abstract We study electron transport characteristics through some Polycyclic Hydrocarbon molecules attached with two metallic electrodes by the use of Green’s function technique. Here we do parametric calculations based on the tight-binding model to investigate the transport properties through such molecular bridges. In this context we also discuss noise power of the current fluctuations and focus our attention on the shot noise contribution to the power spectrum. The electron transport characteristics are significantly influenced by (a) the length of the molecules, (b) the interference effects and (c) the molecule-to-electrodes coupling strength.
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Quantum transport through Polycyclic Hydrocarbon molecules
Physics Letters A, 2007Co-Authors: Santanu K MaitiAbstract:Quantum transport properties through single Polycyclic Hydrocarbon molecules sandwiched between two metallic electrodes are studied by the use of Green's function technique. Here we introduce parametric approach, based on the tight-binding model to investigate the electronic transport through such molecular bridge systems. The electronic transport properties are discussed in two aspects: (a) the molecule-to-electrodes coupling strength and (b) the quantum interference effect.
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Quantum transport through Polycyclic Hydrocarbon molecules
Physics Letters A, 2007Co-Authors: Santanu K MaitiAbstract:Quantum transport properties through single Polycyclic Hydrocarbon molecules attached to two metallic electrodes are studied by the use of Green's function technique. A parametric approach based on the tight-binding model is introduced to investigate the electronic transport through such molecular bridge systems. The transport properties are discussed in the aspects of (a) molecule-to-electrode coupling strength and (b) quantum interference effect.Comment: 8 pages, 6 figure
Greg Warrick - One of the best experts on this subject based on the ideXlab platform.
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Polycyclic Hydrocarbon biomarkers confirm selective incorporation of petroleum in soil and kangaroo rat liver samples near an oil well blowout site in the western san joaquin valley california
Environmental Toxicology and Chemistry, 1996Co-Authors: Isaac Kaplan, Rupo Lee, Greg WarrickAbstract:Following an accidental oil well blow out at an oil field in the western part of the San Joaquin Valley, Kern County, California, soil samples and specimens of Heermann's kangaroo rats (Dipodomys heermanni) were collected from two oil-impacted areas and one control area. The chemical characteristics of the crude oil, soils, and rat livers were compared. Fingerprinting by gas chromatography—mass spectrometry and quantitative evaluation of metabolized petroleum Hydrocarbons was performed on oil, soil extracts, and rat livers. A liver from a domestically raised rabbit was used as an experimental control. The results show that compared to background values for control samples and procedural blanks, there is no significant incorporation of PAHs or low molecular weight n-alkanes (C13–C25) into the liver tissues. The C25 to C35n-alkane range for all soil samples, kangaroo rat livers, and rabbit liver, is dominated by a high abundance of C27, C29, C31, and C33 Hydrocarbons typical of epicuticular plant waxes. In all liver tissue samples, squalene, the cholesterol precursor, is the dominant Hydrocarbon. Although evidence is lacking for metabolism of PAHs and paraffinic petroleum Hydrocarbons, very strong evidence is available for incorporation of a set of Polycyclic Hydrocarbons (biomarkers) belonging to the terpane, sterane, and monoaromatic and triaromatic sterane families, identified by ion monitoring at 191, 217, 253, and 231 m/z, respectively. Because these Hydrocarbons are not known to exist in the biosphere, but are only synthesized during oil- and coal-forming processes, their presence in the liver samples constitutes proof for crude oil incorporation into tissues. This conclusion is further substantiated by the selective incorporation of only the 20S enantiomer of C28 and C29 steranes and aromatic steranes into the livers, with the exclusion of the 20R enantiomer. The results from the study conclusively demonstrate that Polycyclic Hydrocarbon biomarkers provide excellent indices for proof of petroleum exposure and metabolism in some terrestrial herbivores.
Isaac Kaplan - One of the best experts on this subject based on the ideXlab platform.
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Polycyclic Hydrocarbon biomarkers confirm selective incorporation of petroleum in soil and kangaroo rat liver samples near an oil well blowout site in the western san joaquin valley california
Environmental Toxicology and Chemistry, 1996Co-Authors: Isaac Kaplan, Rupo Lee, Greg WarrickAbstract:Following an accidental oil well blow out at an oil field in the western part of the San Joaquin Valley, Kern County, California, soil samples and specimens of Heermann's kangaroo rats (Dipodomys heermanni) were collected from two oil-impacted areas and one control area. The chemical characteristics of the crude oil, soils, and rat livers were compared. Fingerprinting by gas chromatography—mass spectrometry and quantitative evaluation of metabolized petroleum Hydrocarbons was performed on oil, soil extracts, and rat livers. A liver from a domestically raised rabbit was used as an experimental control. The results show that compared to background values for control samples and procedural blanks, there is no significant incorporation of PAHs or low molecular weight n-alkanes (C13–C25) into the liver tissues. The C25 to C35n-alkane range for all soil samples, kangaroo rat livers, and rabbit liver, is dominated by a high abundance of C27, C29, C31, and C33 Hydrocarbons typical of epicuticular plant waxes. In all liver tissue samples, squalene, the cholesterol precursor, is the dominant Hydrocarbon. Although evidence is lacking for metabolism of PAHs and paraffinic petroleum Hydrocarbons, very strong evidence is available for incorporation of a set of Polycyclic Hydrocarbons (biomarkers) belonging to the terpane, sterane, and monoaromatic and triaromatic sterane families, identified by ion monitoring at 191, 217, 253, and 231 m/z, respectively. Because these Hydrocarbons are not known to exist in the biosphere, but are only synthesized during oil- and coal-forming processes, their presence in the liver samples constitutes proof for crude oil incorporation into tissues. This conclusion is further substantiated by the selective incorporation of only the 20S enantiomer of C28 and C29 steranes and aromatic steranes into the livers, with the exclusion of the 20R enantiomer. The results from the study conclusively demonstrate that Polycyclic Hydrocarbon biomarkers provide excellent indices for proof of petroleum exposure and metabolism in some terrestrial herbivores.
Henning Hopf - One of the best experts on this subject based on the ideXlab platform.
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Reciprocal polyhedra and the Euler relationship: cage Hydrocarbons, CnHn and closo-boranes [BxHx]2−
Beilstein Journal of Organic Chemistry, 2011Co-Authors: Michael James Mcglinchey, Henning HopfAbstract:: The closo-boranes B(x)H(x) (+2), or their corresponding anions [B(x)H(x)](2-) (where x = 5 through 12) and polycycloalkanes C(n)H(n) (where n represents even numbers from 6 through 20) exhibit a complementary relationship whereby the structures of the corresponding molecules, e.g., [B(6)H(6)](2-) and C(8)H(8) (cubane), are based on reciprocal polyhedra. The vertices in the closo-boranes correspond to faces in its Polycyclic Hydrocarbon counterpart and vice versa. The different bonding patterns in the two series are described. Several of these Hydrocarbons (cubane, pentagonal dodecahedrane and the trigonal and pentagonal prismanes) are known while others still remain elusive. Synthetic routes to the currently known C(n)H(n) highly symmetrical polyhedral species are briefly summarized and potential routes to those currently unknown are discussed. Finally, the syntheses of the heavier element analogues of cubane and the prismanes are described.
Yuki Kita - One of the best experts on this subject based on the ideXlab platform.
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Theoretical studies of the structures and local aromaticity of conjugated Polycyclic Hydrocarbons using three aromatic indices
Chemical Physics Letters, 2013Co-Authors: Shogo Sakai, Yuki KitaAbstract:Abstract The structures and local aromaticity of some conjugated Polycyclic Hydrocarbons (from the butadienoid, acene, and phenylene series) are studied using ab initio MO and density functional methods. The aromaticities of the molecules are estimated using three indices: the nucleus-independent chemical shift (NICS), the harmonic oscillator model of aromaticity (HOMA), and the index of deviation from aromaticity (IDA). Assessment of the relationships between the structures and the aromatic indices shows that the IDA values correspond best to the characteristics of the conjugated Polycyclic Hydrocarbon structures.