Bibliographies thématiques / Aromatic system

Littérature scientifique sur le sujet « Aromatic system »

Auteur : Grafiati
Publié le 18 mai 2024

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Articles de revues sur le sujet "Aromatic system"

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Wang, Ting, Yuebing Xu, Chengming Shi, Feng Jiang, Bing Liu et Xiaohao Liu. « Direct production of aromatics from syngas over a hybrid FeMn Fischer–Tropsch catalyst and HZSM-5 zeolite : local environment effect and mechanism-directed tuning of the aromatic selectivity ». Catalysis Science & ; Technology 9, no 15 (2019) : 3933–46. http://dx.doi.org/10.1039/c9cy00750d.

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Wu, Weihua, Fang Liu et Seema Singh. « Toward engineeringE. coliwith an autoregulatory system for lignin valorization ». Proceedings of the National Academy of Sciences 115, no 12 (2 mars 2018) : 2970–75. http://dx.doi.org/10.1073/pnas.1720129115.

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Efficient lignin valorization could add more than 10-fold the value gained from burning it for energy and is critical for economic viability of future biorefineries. However, lignin-derived aromatics from biomass pretreatment are known to be potent fermentation inhibitors in microbial production of fuels and other value-added chemicals. In addition, isopropyl-β-d-1-thiogalactopyranoside and other inducers are routinely added into fermentation broth to induce the expression of pathway enzymes, which further adds to the overall process cost. An autoregulatory system that can diminish the aromatics’ toxicity as well as be substrate-inducible can be the key for successful integration of lignin valorization into future lignocellulosic biorefineries. Toward that goal, in this study an autoregulatory system is demonstrated that alleviates the toxicity issue and eliminates the cost of an external inducer. Specifically, this system is composed of a catechol biosynthesis pathway coexpressed with an active aromatic transporter CouP under induction by a vanillin self-inducible promoter, ADH7, to effectively convert the lignin-derived aromatics into value-added chemicals usingEscherichia colias a host. The constructed autoregulatory system can efficiently transport vanillin across the cell membrane and convert it to catechol. Compared with the system without CouP expression, the expression of catechol biosynthesis pathway with transporter CouP significantly improved the catechol yields about 30% and 40% under promoter pTrc and ADH7, respectively. This study demonstrated an aromatic-induced autoregulatory system that enabled conversion of lignin-derived aromatics into catechol without the addition of any costly, external inducers, providing a promising and economically viable route for lignin valorization.
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IWANAMI, Hiroshi. « Aromatic Utilization System in Building. » Journal of the Society of Powder Technology, Japan 29, no 2 (1992) : 124–28. http://dx.doi.org/10.4164/sptj.29.124.

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Minot, C. « Graphite as an aromatic system ». Journal of Physical Chemistry 91, no 25 (décembre 1987) : 6380–85. http://dx.doi.org/10.1021/j100309a013.

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Molčanov, Krešimir, et Biserka Kojić-Prodić. « Towards understanding π-stacking interactions between non-aromatic rings ». IUCrJ 6, no 2 (2 février 2019) : 156–66. http://dx.doi.org/10.1107/s2052252519000186.

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The first systematic study of π interactions between non-aromatic rings, based on the authors' own results from an experimental X-ray charge-density analysis assisted by quantum chemical calculations, is presented. The landmark (non-aromatic) examples include quinoid rings, planar radicals and metal-chelate rings. The results can be summarized as: (i) non-aromatic planar polyenic rings can be stacked, (ii) interactions are more pronounced between systems or rings with little or no π-electron delocalization (e.g. quinones) than those involving delocalized systems (e.g. aromatics), and (iii) the main component of the interaction is electrostatic/multipolar between closed-shell rings, whereas (iv) interactions between radicals involve a significant covalent contribution (multicentric bonding). Thus, stacking covers a wide range of interactions and energies, ranging from weak dispersion to unlocalized two-electron multicentric covalent bonding (`pancake bonding'), allowing a face-to-face stacking arrangement in some chemical species (quinone anions). The predominant interaction in a particular stacked system modulates the physical properties and defines a strategy for crystal engineering of functional materials.
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Yan, Yingying, David Cabrera-Perez, Jintai Lin, Andrea Pozzer, Lu Hu, Dylan B. Millet, William C. Porter et Jos Lelieveld. « Global tropospheric effects of aromatic chemistry with the SAPRC-11 mechanism implemented in GEOS-Chem version 9-02 ». Geoscientific Model Development 12, no 1 (4 janvier 2019) : 111–30. http://dx.doi.org/10.5194/gmd-12-111-2019.

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Abstract. The Goddard Earth Observing System with chemistry (GEOS-Chem) model has been updated with the State-wide Air Pollution Research Center version 11 (SAPRC-11) aromatics chemical mechanism, with the purpose of evaluating global and regional effects of the most abundant aromatics (benzene, toluene, xylenes) on the chemical species important for tropospheric oxidation capacity. The model evaluation based on surface and aircraft observations indicates good agreement for aromatics and ozone. A comparison between scenarios in GEOS-Chem with simplified aromatic chemistry (as in the standard setup, with no ozone formation from related peroxy radicals or recycling of NOx) and with the SAPRC-11 scheme reveals relatively slight changes in ozone, the hydroxyl radical, and nitrogen oxides on a global mean basis (1 %–4 %), although remarkable regional differences (5 %–20 %) exist near the source regions. NOx decreases over the source regions and increases in the remote troposphere, due mainly to more efficient transport of peroxyacetyl nitrate (PAN), which is increased with the SAPRC aromatic chemistry. Model ozone mixing ratios with the updated aromatic chemistry increase by up to 5 ppb (more than 10 %), especially in industrially polluted regions. The ozone change is partly due to the direct influence of aromatic oxidation products on ozone production rates, and in part to the altered spatial distribution of NOx that enhances the tropospheric ozone production efficiency. Improved representation of aromatics is important to simulate the tropospheric oxidation.
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Salter, M., R. G. Knowles et C. I. Pogson. « Transport of the aromatic amino acids into isolated rat liver cells. Properties of uptake by two distinct systems ». Biochemical Journal 233, no 2 (15 janvier 1986) : 499–506. http://dx.doi.org/10.1042/bj2330499.

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The transport of the aromatic amino acids into isolated rat liver cells was studied. There was a rapid and substantial binding of the aromatic amino acids, L-alanine and L-leucine to the plasma membrane. This has important consequences for the determination of rates of transport and intracellular concentrations of the amino acids. Inhibition studies with a variety of substrates of various transport systems gave results consistent with aromatic amino acid transport being catalysed by two systems: a 2-aminobicyclo(2,2,1)heptane-2-carboxylic acid (BCH)-insensitive aromatic D- and L-amino acid-specific system, and the L-type system (BCH-sensitive). The BCH-insensitive component of transport was Na+-independent and facilitated non-concentrative transport of the aromatic amino acids; it was unaffected by culture of liver cells for 24 h, by 48 h starvation, dexamethasone phosphate or glucagon. Kinetic properties of the BCH-inhibitable component were similar to those previously reported for the L2-system in liver cells. The BCH-insensitive component was a comparatively low-Km low-Vmax. transport system that we suggest is similar to the T-transport system previously seen only in human red blood cells. The results are discussed with reference to the importance of the T- and L-systems in the control of aromatic L-amino acid degradation in the liver.
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Nogi, Keisuke, et Hideki Yorimitsu. « Aromatic metamorphosis : conversion of an aromatic skeleton into a different ring system ». Chemical Communications 53, no 29 (2017) : 4055–65. http://dx.doi.org/10.1039/c7cc00078b.

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Bernstein, Max. « Reactions of aromatics in space and connections to the carbon chemistry of Solar System materials ». Proceedings of the International Astronomical Union 4, S251 (février 2008) : 437–40. http://dx.doi.org/10.1017/s1743921308022102.

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AbstractPolycyclic aromatic hydrocarbons (PAHs) and related aromatic materials are thought to be the most abudant class of organic carbon in the universe, being present in virtually all phases of the ISM, and abundant in carbonaceous meteorites and asteroid and comet dust. The basic PAH skeleton is proposed to have formed in outflows of carbon rich stars, and isotopic measurements of extraterrestrial graphitic carbon is consistent with this notion. However, functionalized aromatics bearing oxygen atoms, aliphatic domains, and deuterium enrichments have been extracted from meteorites and more recently been measured in IDPs and Stardust retuned comet samples. Exposure of remnant circumstellar PAHs to energetic processing at low temperature in the presense of H2O is the most parsimonious explanation for these observations.We will present laboratory infrared spectra of various aromatic species and PAH cations in solid H2O under conditions relevant for comparsion to absorptions attributed to PAHs observed towards objects embedded in dense clouds. In addition, we shall describe the reactions of PAHs under these conditions in the lab when they are exposed to energetic processing. Finally, we will propose a mechanism, and make specific predictions regarding the structures and distribution of deuterium that should be observed in extraterrestrial samples if low temperature ice radiation chemistry is playing a role in the formation of the molecules seen in Solar System materials.
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Zhu, Congqing, Qin Zhu, Jinglan Fan, Jun Zhu, Xumin He, Xiao-Yu Cao et Haiping Xia. « A Metal-Bridged Tricyclic Aromatic System : Synthesis of Osmium Polycyclic Aromatic Complexes ». Angewandte Chemie International Edition 53, no 24 (29 avril 2014) : 6232–36. http://dx.doi.org/10.1002/anie.201403245.

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Thèses sur le sujet "Aromatic system"

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Mancinelli, Michele <1981&gt. « Conformation and Stereodynamic of Hindered Aromatic System ». Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2009. http://amsdottorato.unibo.it/1344/2/michele_mancinelli_tesi.pdf.

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The preparation of conformationally hindered molecules and their study by DNMR and computational methods are my thesis’s core. In the first chapter, the conformations and the stereodynamics of symmetrically ortho-disubstituted aryl carbinols and aryl ethers are described. In the second chapter, the structures of axially chiral atropisomers of hindered biphenyl carbinols are studied. In the third chapter, the steric barriers and the -barrier of 1,8-di-aylbiphenylenes are determined. Interesting atropisomers are found in the cases of arylanthrones, arylanthraquinones and arylanthracenes and are reported in the fourth chapter. By the combined use of dynamic NMR, ECD spectroscopy and DFT computations, the conformations and the absolute configurations of 2-Naphthylalkylsulfoxides are studied in the fifth chapter. In the last chapter, a new synthetic route to ,’-arylated secondary or tertiary alcohols by lithiated O-benzyl-carbamates carrying an N-aryl substituent and DFT calculations to determinate the cyclic intermediate are reported. This work was done in the research group of Prof. Jonathan Clayden, at the University of Manchester.
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Mancinelli, Michele <1981&gt. « Conformation and Stereodynamic of Hindered Aromatic System ». Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2009. http://amsdottorato.unibo.it/1344/.

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The preparation of conformationally hindered molecules and their study by DNMR and computational methods are my thesis’s core. In the first chapter, the conformations and the stereodynamics of symmetrically ortho-disubstituted aryl carbinols and aryl ethers are described. In the second chapter, the structures of axially chiral atropisomers of hindered biphenyl carbinols are studied. In the third chapter, the steric barriers and the -barrier of 1,8-di-aylbiphenylenes are determined. Interesting atropisomers are found in the cases of arylanthrones, arylanthraquinones and arylanthracenes and are reported in the fourth chapter. By the combined use of dynamic NMR, ECD spectroscopy and DFT computations, the conformations and the absolute configurations of 2-Naphthylalkylsulfoxides are studied in the fifth chapter. In the last chapter, a new synthetic route to ,’-arylated secondary or tertiary alcohols by lithiated O-benzyl-carbamates carrying an N-aryl substituent and DFT calculations to determinate the cyclic intermediate are reported. This work was done in the research group of Prof. Jonathan Clayden, at the University of Manchester.
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Terraneo, G. « Simple model system to study sugar/aromatic interactions ». Doctoral thesis, Università degli Studi di Milano, 2006. http://hdl.handle.net/2434/143397.

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A molecular scaffold was identified which enables the establishment of intramolecular interactions between a monosaccharide and a nearby phenyl ring. A group of molecules containing four different monosaccharides (glucose, galactose, N-acetyl-glucosamine and N-acetyl-galactosamine) was synthesized and used to investigate the extent and nature of this carbohydrate-arene interaction, as well as the effect on the overall 3D structure of the molecules involved. The sugar-aromatic distance was evaluated by rigorous NMR studies supported by molecular modeling, and found to be constant throughout the series, independent of the nature of the sugar, and of the conformational behaviour of the fragment connecting the two elements. Ab initio calculations at the B3LYP/DZV(2d,p) level of theory enable the analysis of the electronic nature of the interaction. The study shows that, given the opportunity, persistent intramolecular aromatic-sugar interactions can be established and can significantly influence overall molecular shape and energetics. These results have important implications in the design of structural mimics of oligosaccharides
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Castelo, Alves Ferreira Frederico. « Membrane aromatic recovery system (MARS) : theoretical analysis and industrial applications ». Thesis, Imperial College London, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.409559.

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Daisley, Gavin Rhys. « Membrane Aromatic Recovery System (MARS) : improved membranes and a further application ». Thesis, Imperial College London, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.508324.

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Cameron, Grant William Wright. « A transport system for the uptake of aromatic carboxylates in Aspergillus ». Thesis, University of Newcastle Upon Tyne, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.238930.

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Dicken, Laura. « A Study of Polycyclic Aromatic Hydrocarbons During Combustion in an AFBC System ». TopSCHOLAR®, 1997. http://digitalcommons.wku.edu/theses/302.

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The purpose of this study was to develop the on-line method of analysis which leads to the study of polycyclic aromatic hydrocarbons (PAHs) during combustion in an atmospheric fluidized bed combustor (AFBC) system. The study of PAHs is important because they may be produced upon the combustion of coal. The US EPA prioritizes PAHs as major pollutants due to their mutagenic and carcinogenic effects. Standards of PAHs were analyzed by injection into the gas chromatograph-mass spectrometer (GC-MS). These standards were then analyzed using the on-line method. Two coals were burned in the AFBC system and effluent samples were collected. These were analyzed with the GC-MS to see if there were any PAHs or chlorobenzenes present.
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Addleton, Andrew Mark. « Microbial degradation of aromatic compounds in a Gravel Bed Hydroponic (GBH) system ». Thesis, University of Portsmouth, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310474.

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Chung, Ming Kei. « Assessment of phytotoxic effects of PAHs and DDTs in solid-phase system using microalgal bioassays ». HKBU Institutional Repository, 2005. http://repository.hkbu.edu.hk/etd_ra/628.

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Dastgir, Muhammad Ghulam. « The development of synthetic membranes and their performance in the Membrane Aromatic Recovery System (MARS) ». Thesis, Imperial College London, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.429374.

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Livres sur le sujet "Aromatic system"

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Addleton, Andrew. Microbial degradation of aromatic compounds in a gravel bed hydroponic (GBH) system. Portsmouth : University of Portsmouth, 1997.

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J, McMillin Debra, Louisiana Universities Marine Consortium et United States. Minerals Management Service. Gulf of Mexico OCS Region, dir. Fate and transport of particle-reactive normal, alkylated and heterocyclic aromatic hydrocarbons in a sediment-water-colloid system : [final]. New Orleans, LA : U.S. Dept. of the Interior, Minerals Management Service, Gulf of Mexico OCS Region, 1993.

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Tracey, Gregory A. Application of in situ UV spectrometry for characterization of harbor sediment. Concord, MA : U.S. Army Corps of Engineers, New England District, 2000.

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S, Lee Linda, et National Exposure Research Laboratory (U.S.). Ecosystems Research Division, dir. Modeling soil-water distribution of aromatic amines in water saturated soil systems. Athens, GA : U.S. Environmental Protection Agency, Ecosystems Research Division, National Exposure Research Laboratory, 2000.

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S, Lee Linda, et National Exposure Research Laboratory (U.S.). Ecosystems Research Division, dir. Modeling soil-water distribution of aromatic amines in water saturated soil systems. Athens, GA : U.S. Environmental Protection Agency, Ecosystems Research Division, National Exposure Research Laboratory, 2000.

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S, Lee Linda, et National Exposure Research Laboratory (U.S.). Ecosystems Research Division., dir. Modeling soil-water distribution of aromatic amines in water saturated soil systems. Athens, GA : U.S. Environmental Protection Agency, Ecosystems Research Division, National Exposure Research Laboratory, 2000.

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S, Lee Linda, et National Exposure Research Laboratory (U.S.). Ecosystems Research Division., dir. Modeling soil-water distribution of aromatic amines in water saturated soil systems. Athens, GA : U.S. Environmental Protection Agency, Ecosystems Research Division, National Exposure Research Laboratory, 2000.

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Fu, Jaw-Kwei. Pollutant sorption to soils and sediments in organic/aqueous solvent systems. Athens, GA : U.S. Environmental Protection Agency, Environmental Research Laboratory, 1985.

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Fu, Jaw-Kwei. Pollutant sorption to soils and sediments in organic/aqueous solvent systems. Athens, GA : U.S. Environmental Protection Agency, Environmental Research Laboratory, 1985.

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Louch, Jeff. Semipermeable membrane devices (SPMDs) for determining absolute or relative water column concentrations of non-polar chemicals in aqueous systems / by Jeff Louch. Research Triangle Park, N.C : National Council for Air and Stream Improvement, 2002.

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Chapitres de livres sur le sujet "Aromatic system"

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Bansal, Monika, et Shabir H. Wani. « System Biology Approach for Functional Analysis of Medicinal and Aromatic Plants ». Dans Medicinal and Aromatic Plants, 629–43. Cham : Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-58975-2_24.

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Burchiel, Scott W., et Jun Gao. « Polycyclic Aromatic Hydrocarbons and the Immune System ». Dans Encyclopedia of Immunotoxicology, 710–15. Berlin, Heidelberg : Springer Berlin Heidelberg, 2015. http://dx.doi.org/10.1007/978-3-642-54596-2_1192.

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Burchiel, Scott W., et Jun Gao. « Polycyclic Aromatic Hydrocarbons and the Immune System ». Dans Encyclopedia of Immunotoxicology, 1–7. Berlin, Heidelberg : Springer Berlin Heidelberg, 2014. http://dx.doi.org/10.1007/978-3-642-27786-3_1192-4.

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Inoue, Kengo, et Hideaki Nojiri. « Structure and Function of Aromatic-Ring Hydroxylating Dioxygenase System ». Dans Biodegradative Bacteria, 181–205. Tokyo : Springer Japan, 2013. http://dx.doi.org/10.1007/978-4-431-54520-0_9.

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Sun, Gang, Zhiming Zhou, Mengzhong Zhu et Wei Quan. « Study on High-Sensitivity Detection System of Aromatic Hydrocarbons ». Dans Communications in Computer and Information Science, 468–75. Berlin, Heidelberg : Springer Berlin Heidelberg, 2012. http://dx.doi.org/10.1007/978-3-642-31968-6_56.

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Fukuda, Masao. « Rhodococcus Multiple-Enzyme and Parallel-Degradation System for Aromatic Compounds ». Dans Biodegradative Bacteria, 3–18. Tokyo : Springer Japan, 2013. http://dx.doi.org/10.1007/978-4-431-54520-0_1.

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Pengelly, Andrew. « Phenols. » Dans The constituents of medicinal plants, 18–40. 3e éd. Wallingford : CABI, 2021. http://dx.doi.org/10.1079/9781789243079.0002.

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Abstract This chapter focuses on phenols and their pharmacological properties. Phenols are one of the largest groups of secondary plant constituents. They are aromatic alcohols since the hydroxyl group is always attached to a benzene ring. Like all alcohols, the names of phenols almost always end in the letters 'ol'. In addition, the ring system may bear other substitutes, such as methyl groups and carboxylic acid.
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Shivakumara, K. T., Satyajit Roy et R. P. Meena. « Integrated Pest and Disease Management in Medicinal and Aromatic Plants-Based Cropping System ». Dans Integrated Pest Management in Diverse Cropping Systems, 517–48. New York : Apple Academic Press, 2022. http://dx.doi.org/10.1201/9781003304524-19.

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Horiuchi, Tsutomu, Yuko Ueno, Osamu Niwa, Hao-shen Zhou, Takeo Yamada et Itaru Honma. « Portable System for Selective Detection of Aromatic VOC Mixture-Gases Using a Microfluidic Device ». Dans Micro Total Analysis Systems 2002, 536–38. Dordrecht : Springer Netherlands, 2002. http://dx.doi.org/10.1007/978-94-010-0295-0_179.

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Catellani, Marta. « Novel Methods of Aromatic Functionalization Using Palladium and Norbornene as a Unique Catalytic System ». Dans Topics in Organometallic Chemistry, 21–53. Berlin, Heidelberg : Springer Berlin Heidelberg, 2005. http://dx.doi.org/10.1007/b104126.

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Actes de conférences sur le sujet "Aromatic system"

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Dara, Satyadileep, Ibrahim Khan, Eisa Al Jenaibi, Subhendu Sengupta, Vincent Goveas, Nawal Al Yahyaee, Salisu Ibrahim, Anoop Jagannath et Abhijeet Raj. « Deployment of a Novel Soft Sensor in the Real Time Optimizer Architecture to Enhance the Integrity and Energy Efficiency of Sulfur Recovery Units ». Dans ADIPEC. SPE, 2022. http://dx.doi.org/10.2118/211303-ms.

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Abstract Commercial analyzers for measuring the aromatics in the Claus furnace exit gas are currently not available and this leads to sub-optimal energy efficiency and poses asset integrity concerns. To address this problem a high-fidelity model is developed to function as a real time analyzer. Objective of this work is to incorporate the soft sensor in the architecture of Real Time Optimizer (RTO) to monitor the presence of aromatics in the Claus furnace exit stream. The soft sensor is incorporated in the RTO server which provides the access to the plant operating data and the DCS (Distributed Control System). Soft sensor function in the RTO involves the following steps: Soft sensor accesses the plant data and collects the needful input data for simulation Simulation software available in the RTO executes the softs sensor model simulation and generates the aromatics composition data Aromatics composition data is written to the DCS interface as a soft measurement Operators monitor the aromatic composition and accordingly adjust the fuel gas firing Aromatic soft sensor is developed as a kinetic model, which is function of rate parameters of several key reactions of the Claus furnace. The kinetic model of the Claus furnace is incorporated in a process simulation model and catalytic convertors are simulated too. Model is validated with large plant data to show that model predicts furnace temperature within +/- 5% error and aromatics composition within +/- 5 ppm. Simulation analysis shows that the furnace temperature can be decreased by at least 5 °C while ensuring no BTEX slip. Such change in furnace temperature leads to a reduction in fuel gas flow by ~200 Nm3/h, which translates to a monetary benefit of 0.5 million $/yr. Deployment of the soft sensor is currently in progress through engagement with RTO licensor. To the best knowledge of authors, currently, there is no simulator in the market which can adequately model aromatics oxidation phenomena and predict the aromatic content in the furnace exit. This soft sensor being deployed is novel and first of its kind and expected to achieve a sustainable energy efficiency.
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Laws, William R., J. B. Alexander Ross, Panayotis G. Katsoyannis et Herman R. Wyssbrod. « Time-Resolved Fluorometry of the Aromatic Amino Acids ». Dans Free-Electron Laser Applications in the Ultraviolet. Washington, D.C. : Optica Publishing Group, 1988. http://dx.doi.org/10.1364/fel.1988.fa4.

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Fluorescence spectroscopy is an extremely useful technique for understanding the complex relationships between structure and function of biological systems. The advantages of fluorescence spectroscopy include sensitivity (only a small amount of sample is needed), a wide range of time scales in which to measure particular processes (picoseconds to seconds), the ability to examine the biological system in aqueous solution, as well as many physical parameters that can be measured (quantum yield, lifetime, emission energies, anisotropy) to reveal different aspects of the system.
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Leparoux, Julien, Renaud Lecourt et Olivier Penanhoat. « Effect of Aromatics in Jet Fuels on Spray Characteristics Downstream of an Aeronautical Pressure Swirl Atomizer ». Dans ASME Turbo Expo 2016 : Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/gt2016-56565.

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Standard aeronautic fuels have a lower limit of aromatics of 8% (by volume) with about 18% for regular Jet A1. It has been shown that aromatics contained in Jet fuel have an impact on the fine particle emissions. In order to reduce these emissions, alternative fuels with lower aromatic content have been identified as a promising solution. Change Jet fuel composition can have several effects on spray and combustion behaviors, among others: atomization process, droplet evaporation, flame structure, pollutant and particle emissions. Then, it is necessary to evaluate the impact of this change on gas turbine performance and operability. The present study is focused on the spray behavior investigation with different aromatic content. Four Jet fuels are investigated including conventional Jet A1 kerosene, drop-in fuel with a mixture of half conventional Jet fuel and synthetic paraffinic kerosene (SPK), SPK with 8% of aromatics and pure SPK. The tests are performed at atmospheric conditions on the MERCATO testbed located at ONERA (FR). Phase Doppler Anemometry (PDA) measurements are carried out for the four fuels on an injection system composed of a pressure swirl atomizer and an air swirler. In this paper, a spray analysis of liquid velocity and droplet diameter measurements is described and linked to the variations of fuel properties. In the range of parameters covered by the four different fuels, it is shown that the spray behavior of each fuel is similar to the conventional Jet A1.
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Lizeng, Zhao, Lu Zhengzhong, Zhang Xiulang, Zhang Dongxiang, Mi Xin, Nie Yuxin, Wang Duoyuan et al. « Photon-Gated Photochemical Hole Burning in Zinc-Tetrabenzoporphyrin/Aromatic Cyanide System ». Dans Persistent Spectral Hole Burning : Science and Applications. Washington, D.C. : Optica Publishing Group, 1991. http://dx.doi.org/10.1364/pshb.1991.the6.

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The group of Moerner,et al., first reported two-color hole-burning by donor-acceptor electron transfer for a derivative of zinc-tetrabenzoporphyrin as a donor with halomethane acceptors in a poly (methyl methacrylate) (PMMA) thin film [1]. Their results have opened up a new class of materials for photon-gating.
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Shao Yixian et Xu Xiaoqing. « Progress on sample pretreatment techniques for polycyclic aromatic hydrocarbons in water system ». Dans 2011 International Conference on Electric Technology and Civil Engineering (ICETCE). IEEE, 2011. http://dx.doi.org/10.1109/icetce.2011.5776307.

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Iyoda, M., M. Fukuda, S. Sasaki et M. Yoshida. « Multi-tetrathiafulvalene system linked by 1,3- and 1,3,5-positions of aromatic rings ». Dans International Conference on Science and Technology of Synthetic Metals. IEEE, 1994. http://dx.doi.org/10.1109/stsm.1994.835442.

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Blagojević Filipović, Jelena, Dubravka Z. Vojislavljević-Vasilev et Snežana D. Zarić. « Influence of Coordination on OH/π and NH/π Interactions ». Dans 2nd International Conference on Chemo and Bioinformatics. Institute for Information Technologies, University of Kragujevac, 2023. http://dx.doi.org/10.46793/iccbi23.649bf.

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The interactions of noncoordinated water or ammonia molecules with aromatic rings, as well as coordinated water or coordinated ammonia molecules with aromatic rings have been investigated by searching the Cambridge Structural Database (CSD) and through quantum-chemical calculations. The data from the CSD show that for noncoordinated systems distances between the interacting fragments are the shortest in case of negative C6-aromatic groups and the longest in case of positive C6-aromatic groups. In the case of contacts between coordinated water or ammonia molecules and C6-aromatic group, oppositely charged fragments are mutually closer than the neutral fragments. The DFT calculations for the water/benzene system yield an interaction energy of -2.97 kcal/mol, while for the [Zn(H2O)6]2+/C6H6 system the interaction energy is -14.72 kcal/mol. For the ammonia/benzene system, the DFT calculations yield an interaction energy of -2.28 kcal/mol, while for the [Zn(NH3)6]2+/C6H6 system it is -15.50 kcal/mol. The results show that there is an influence of water or ammonia coordination on OH/π or NH/π interactions; the interactions of coordinated species are significantly stronger. OH/π and NH/π interactions are comparable in both cases. OH/π interactions are slightly stronger than NH/π interactions in the case of noncoordinated molecules due to a higher partially positive charge on the hydrogen atom of the water molecule, but this is not necessarily the case for the coordinated molecules due to additional interactions that can occur between the benzene ring and the other ligands present in the complex.
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Zhu, Shengfeng, Shengkang Liang et Xueyi You. « Effect of Rhamnolipid Biosurfactant on Solubilization and Biodegradation of Polycyclic Aromatic Hydrocarbons ». Dans 2013 Third International Conference on Intelligent System Design and Engineering Applications (ISDEA). IEEE, 2013. http://dx.doi.org/10.1109/isdea.2012.156.

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Almajid, Hussain, Alaa Shawly et Abdullah Al-Qasim. « Developing an Integrated Solution to Remove and Inhibit Asphaltene Deposits Through a Laboratory and Field Proven Approach ». Dans International Petroleum Technology Conference. IPTC, 2022. http://dx.doi.org/10.2523/iptc-22366-ms.

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Abstract Asphaltene deposits are considered one of the most common issues facing oil fields with low particle stability that can result in loss of well potential, jeopardize wellbore accessibility and cause premature electrical submersible pump (ESP) failures. Traditionally, these deposits are treated with hydrocarbon based solvents, which have low flashpoints, making them hazardous and expensive. The objective of this paper is to provide a comprehensive solution to effectively remove asphaltene and sand fill accumulation that forms in the near wellbore region. This paper will also provide a computational analysis to accurately predict asphaltene precipitation during the production phase for optimized inhibition process. A laboratory approach was implemented to test the effectiveness of different water based solvent types, including aromatic, aliphatic and heteroatom instead of the commonly used hydrocarbon solvents such as xylene to dissolve asphaltene samples collected from the field and placed under anaerobic conditions. A thorough evaluation of fundamental asphaltene properties, including saturates, aromatics, resins and onset pressure, is incorporated into a computational model to understand and accurately predict asphaltene precipitation behavior. The newly developed system offers significant advantages compared to the traditional system in terms of treatment effectiveness, deployment cost and health, safety, and environment (HSE) due to its relatively high flashpoint. The new system utilizes a water based solvent that leaves the formation in a water wet state instead of oil wet, thus creating a barrier layer that will delay asphaltene accumulation and reduce treatment frequency. Field implementation and post-job results utilizing this newly developed water based aromatic solvent will be discussed, including treatment effectiveness to dissolve downhole asphaltene accumulations. Asphaltene inhibition programs have been implemented based on the results acquired from this model and frequent inspection conducted showed no asphaltene deposition over extended production periods. This paper provides a laboratory proven and field tested water based aromatic solvent that is effective in dissolving asphaltene accumulations resulting in improved well potential while reducing the frequency of required treatments thus maximizing productivity. This system is unique as it provides a high flashpoint water/solvent mixture with solvency power often greater than xylene with the additional benefit of leaving the formation strongly water-wet. The developed computational model helped to reduce the treatment frequency resulting in reduced expenses and sustained production.
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Yuxin, Nie, Zhao Lizeng, Wang Duoyuan et Hu Lingzhi. « Spectral Hole Stability and Laser Induced Hole-Filling in Zinc-Tetrabenzoporphurin/Aromatic Cyanide System ». Dans Spectral Hole-Burning and Related Spectroscopies : Science and Applications. Washington, D.C. : Optica Publishing Group, 1994. http://dx.doi.org/10.1364/shbs.1994.wd21.

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The importance of photon-gated persistent spectral hole burning for scientific studies and for frequency domain optical storage (FDOS) has stimulated much recent research to discover new photon-gated materials. For FDOS the practical materials should posses the characteristics of high hole formation efficiency, large multiplicity of spectral hole, good thermal and spectral stability etc.
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Rapports d'organisations sur le sujet "Aromatic system"

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Cesar, J. R., et O. H. Ardakani. Organic geochemistry of the Montney Formation : new insights about the source of hydrocarbons, their accumulation history and post accumulation processes. Natural Resources Canada/CMSS/Information Management, 2022. http://dx.doi.org/10.4095/329788.

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This study consists of a non-traditional molecular and stable isotope approach to analyze organic matter (soluble bitumen and produced oil/condensate) from the Montney Formation low-permeability reservoirs, with the purpose of identifying source(s) of hydrocarbons, accumulation history and post accumulation processes. The same approach bases on the distribution of compound classes such as aromatic carotenoids, polycyclic aromatic hydrocarbons (PAHs), bicyclic alkanes, and oxygen-polar compounds. The geochemical screening has been enhanced with performing compound specific isotope analysis (CSIA) of n-alkanes and selected aromatic hydrocarbons. Widely spread PAHs, the presence of molecular indicators of euxinia, and hydrocarbon mixtures identified using CSIA profiles, are some of the key findings from this research, which will improve our understanding of the Montney petroleum system(s).
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Edward C. Lim. INTRAMOLECULAR CHARGE AND ENERGY TRANSFER IN MULTICHROMOPHORIC AROMATIC SYSTEMS. Office of Scientific and Technical Information (OSTI), septembre 2008. http://dx.doi.org/10.2172/936771.

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Simon, James E., Uri M. Peiper, Gaines Miles, A. Hetzroni, Amos Mizrach et Denys J. Charles. Electronic Sensing of Fruit Ripeness Based on Volatile Gas Emissions. United States Department of Agriculture, octobre 1994. http://dx.doi.org/10.32747/1994.7568762.bard.

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An electronic sensory system for the evaluation of headspace volatiles was developed to determine fruit ripeness and quality. Two prototype systems were designed, constructed, and later modified. The first is an improved version of our original prototype electronic sniffer using a single head sensing unit for use as a single or paired unit placed on an individual fruit surface for applications in the field, lab, or industry. The second electronic sniffer utilizes a matrix of gas sensors, each selected for differential sensitivity to a range of volatile compounds. This system is more sophisticated as it uses multiple gas sensors, but was found to enhance the ability of the sniffer to classify fruit ripeness and quality relative to a single gas sensor. This second sniffer was designed and constructed for the sampling of fresh-cut or whole packs of fruits such as packaged strawberries and blueberries, and can serve as a prototype for research or commercial applications. Results demonstrate that electronic sensing of fruit ripeness based on aromatic volatile gas emissions can be used successfully with fresh frits. Aroma sensing was successful for classifying ripeness in muskmelons, including different cultivars, apples, blueberries, strawberries, and in a complimentary BARD project on tomatoes. This system compared favorably to the physicochemical measurements traditionally employed to assess fruit maturity. This nondestructive sensory system can detect the presence of physically damaged fruits and shows excellent application for use in quality assessment. Electronic sensors of the tin oxide type were evaluated for specificity toward a wide range of volatiles associated with fruit ripeness. Sensors were identified that detected a broad range of alcohols, aldehydes, esters, hydrocarbons, and volatile sulfur compounds, as well as individual volatiles associated with fruit ripening across a wide concentration range. Sensors are not compound specific, thus, the matrix of sensors coupled with discrimination analysis provides a fingerprint to identify the presence of compounds and to assess alterations in fresh products due to alterations in volatile emissions. Engineering developments led to the development of a system to compensate for temperature and relative humidity relative to on-line aroma sensing with melons for ripeness determination and to reduce response time, thus permitting the electronic sniffer to be used for monitoring both fresh and processed food products. The sniffer provides a fast, reliable and nondestructive tool to assess fruit ripeness and quality. We hope that our work will foster the introduction and utilization of this emerging technology into the agricultural and horticultural
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Aharoni, Asaph, Zhangjun Fei, Efraim Lewinsohn, Arthur Schaffer et Yaakov Tadmor. System Approach to Understanding the Metabolic Diversity in Melon. United States Department of Agriculture, juillet 2013. http://dx.doi.org/10.32747/2013.7593400.bard.

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Fruit quality is determined by numerous genetic factors that affect taste, aroma, ‎color, texture, nutritional value and shelf life. To unravel the genetic components ‎involved in the metabolic pathways behind these traits, the major goal of the project was to identify novel genes that are involved in, or that regulate, these pathways using correlation analysis between genotype, metabolite and gene expression data. The original and specific research objectives were: (1) Collection of replicated fruit from a population of 96 RI lines derived from parents distinguished by great diversity in fruit development and quality phenotypes, (2) Phenotypic and metabolic profiling of mature fruit from all 96 RI lines and their parents, (3) 454 pyrosequencing of cDNA representing mRNA of mature fruit from each line to facilitate gene expression analysis based on relative EST abundance, (4) Development of a database modeled after an existing database developed for tomato introgression lines (ILs) to facilitate online data analysis by members of this project and by researchers around the world. The main functions of the database will be to store and present metabolite and gene expression data so that correlations can be drawn between variation in target traits or metabolites across the RI population members and variation in gene expression to identify candidate genes which may impact phenotypic and chemical traits of interest, (5) Selection of RI lines for segregation and/or hybridization (crosses) analysis to ascertain whether or not genes associated with traits through gene expression/metabolite correlation analysis are indeed contributors to said traits. The overall research strategy was to utilize an available recombinant inbred population of melon (Cucumis melo L.) derived from phenotypically diverse parents and for which over 800 molecular markers have been mapped for the association of metabolic trait and gene expression QTLs. Transcriptomic data were obtained by high throughput sequencing using the Illumina platform instead of the originally planned 454 platform. The change was due to the fast advancement and proven advantages of the Illumina platform, as explained in the first annual scientific report. Metabolic data were collected using both targeted (sugars, organic acids, carotenoids) and non-targeted metabolomics analysis methodologies. Genes whose expression patterns were associated with variation of particular metabolites or fruit quality traits represent candidates for the molecular mechanisms that underlie them. Candidate genes that may encode enzymes catalyzingbiosynthetic steps in the production of volatile compounds of interest, downstream catabolic processes of aromatic amino acids and regulatory genes were selected and are in the process of functional analyses. Several of these are genes represent unanticipated effectors of compound accumulation that could not be identified using traditional approaches. According to the original plan, the Cucurbit Genomics Network (http://www.icugi.org/), developed through an earlier BARD project (IS-3333-02), was expanded to serve as a public portal for the extensive metabolomics and transcriptomic data resulting from the current project. Importantly, this database was also expanded to include genomic and metabolomic resources of all the cucurbit crops, including genomes of cucumber and watermelon, EST collections, genetic maps, metabolite data and additional information. In addition, the database provides tools enabling researchers to identify genes, the expression patterns of which correlate with traits of interest. The project has significantly expanded the existing EST resource for melon and provides new molecular tools for marker-assisted selection. This information will be opened to the public by the end of 2013, upon the first publication describing the transcriptomic and metabolomics resources developed through the project. In addition, well-characterized RI lines are available to enable targeted breeding for genes of interest. Segregation of the RI lines for specific metabolites of interest has been shown, demonstrating the utility in these lines and our new molecular and metabolic data as a basis for selection targeting specific flavor, quality, nutritional and/or defensive compounds. To summarize, all the specific goals of the project have been achieved and in many cases exceeded. Large scale trascriptomic and metabolomic resources have been developed for melon and will soon become available to the community. The usefulness of these has been validated. A number of novel genes involved in fruit ripening have been selected and are currently being functionally analyzed. We thus fully addressed our obligations to the project. In our view, however, the potential value of the project outcomes as ultimately manifested may be far greater than originally anticipated. The resources developed and expanded under this project, and the tools created for using them will enable us, and others, to continue to employ resulting data and discoveries in future studies with benefits both in basic and applied agricultural - scientific research.
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Gurevitz, Michael, Michael Adams et Eliahu Zlotkin. Insect Specific Alpha Neurotoxins from Scorpion Venoms : Mode of Action and Structure-Function Relationships. United States Department of Agriculture, juin 1996. http://dx.doi.org/10.32747/1996.7613029.bard.

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This study was motivated by the need to develop new means and approaches to the design of future, environmentally-safe, insecticides. Utilization of anti-insect selective toxins from scorpion venoms and clarification of the molecular basis for their specificity, are a major focus in this project and may have an applicative value. Our study concentrated on the highly insecticidal toxin, LqhaIT, and was devoted to: (I) Characterization of the neuropharmacological and electrophysiological features of this toxin. (II) Establishment of a genetic system for studying structure/activity relationships of the toxin. (III) Analysis of the insecticidal efficacy of an entomopathogenic baculovirus engineered and expressing LqhaIT. The results obtained in this project suggest that: 1) The receptor binding site of LqhaIT on insect sodium channels differs most likely from its analogous receptor site 3 on vertebrate sodium channels. 2) The effects of LqhaIT are presynaptic. Hyperexcitation at the neuromuscular results from dramatic slowing of sodium channel inactivation and enhanced peak sodium currents causes by LqhaIT. 3) The putative toxic surface of LqhaIT involves aromatic and charged amino acid residues located around the C-terminal region and five-residue-turn of the toxin (unpublished). 4) The anti-insect/anti-mammalian toxicity ratio can be altered by site-directed mutagenesis (publication 8). This effect was partly shown at the level of sodium channel function. 5) The insecticidal efficacy of AcNPV baculovirus increased to a great extent when infection was accompanied by expression of LqhaIT (publication 5).
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Herman, J. S., A. L. Mills, G. M. Hornberger et W. R. Kelly. The kinetics of aromatic-hydrocarbon biodegradation and concomitant geochemical reactions pertinent to groundwater systems. Office of Scientific and Technical Information (OSTI), février 1992. http://dx.doi.org/10.2172/5912188.

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Herman, J. S. [The kinetics of aromatic-hydrocarbon biodegradation and concomitant geochemical reactions pertinent to groundwater systems.] Final report. Office of Scientific and Technical Information (OSTI), juillet 1994. http://dx.doi.org/10.2172/762043.

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Hoylman, Anne M. Fate of polycyclic aromatic hydrocarbons in plant-soil systems : Plant responses to a chemical stress in the root zone. Office of Scientific and Technical Information (OSTI), janvier 1994. http://dx.doi.org/10.2172/10121890.

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Herman, J. S., A. L. Mills, G. M. Hornberger et W. R. Kelly. The kinetics of aromatic-hydrocarbon biodegradation and concomitant geochemical reactions pertinent to groundwater systems. Six-month technical progress report. Office of Scientific and Technical Information (OSTI), février 1992. http://dx.doi.org/10.2172/10123591.

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Brel, Valery K. Development of the New Approaches in Designing of Fluoroorganic Derivatives Sulfur (Unsaturated, Heterocyclic, Aromatic Molecular Systems and Polyfunctional Organic Compounds). Fort Belvoir, VA : Defense Technical Information Center, novembre 2005. http://dx.doi.org/10.21236/ada447113.

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