Documents about Polycyclic Aromatic
2005_hw7
UNC, ENVR 430
Excerpt: ... ENVR130 Fall 2005 Homework #7 Due Fri Oct 28, 2005 Do not use more than 2 sides of paper for your answers Question 1: List and briefly describe two endogenous sources of ROS and two exogenous sources of ROS. Question 2: Show how metabolites of the polycyclic aromatic hydrocarbon benzo[a]pyrene can undergo redox cycling to lead to generation of reactive oxygen species. Question 3: Rats are susceptible to the carcinogenic effects of Aflatoxin B1 (AFB1), mice are generally not susceptible. From what you know of the activation pathway for AFB1(see Dr. Gold and Dr. Rusyns lecture notes) and the detoxication pathways for this class of active intermediates, suggest two possible explanations for this species difference in susceptibility. How could you try to find out if humans are more like rats or more like mice ? ...
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peeters
Toledo, AY 07
Excerpt: ... Polycyclic Aromatic Hydrocarbons as Astrophysical Probe The infrared spectra of a wide variety of objects associated with dust and gas are dominated by the well-known emission features at 3.3, 6.2, 7.7, 8.6, 11.2 and 12.7 micron. These bands are generally attributed to fluorescence from UV pumped large Polycyclic Aromatic Hydrocarbon (PAH) molecules. In this talk, I will review the spectral characteristics of these PAH bands and their dependence on the local physical conditions of their environment. These results will be interpreted through comparison with the ongoing laboratory studies and the theoretical calculations on the IR characteristics of PAHs underway at the NASA Ames Research Center. Finally, I will explore the use of the PAHs as a diagnostic tool. ...
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pahs
Laurentian, CHEM 200203
Excerpt: ... Dr. Kevin Smith WHAT ARE PAHs? Polycyclic Aromatic Hydrocarbons (PAHs) Polycyclic aromatic hydrocarbons or (PAHs) are a class of very stable organic molecules made up of only carbon and hydrogen. Consider these as fused benzene ring structures - a variety of representative PAHs can be seen below. These molecules are planar, with each carbon having three neighboring atoms much like graphite (pencil lead). naphthalene anthracene phenanthrene pyrene benzo[a]pyrene coronene HOW CAN I BE EXPOSED TO PAHs? PAHs are found throughout our environment in the air, water, and soil, and can persist in the environment for months or years. PAHs occur naturally in coal, crude oil, gasoline, coal-tar pitch, creosote, and asphalt. When coal is converted to natural gas, PAHs can be released. PAHs are also produced during the incomplete combustion of fossil fuels, garbage, or other organic substances. The less efficient the burning process, the more PAHs are given off. Forest fires and volcanoes produce PAHs natu ...
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pahs
Laurentian, CHEM 200303
Excerpt: ... Polycyclic Aromatic Hydrocarbons (PAHs) WHAT ARE PAHs? Polycyclic aromatic hydrocarbons or (PAHs) are a class of very stable organic molecules made up of only carbon and hydrogen. Consider these as fused benzene ring structures - a variety of representative PAHs can be seen below. These molecules are planar, with each carbon having three neighboring atoms much like graphite (pencil lead). HOW CAN I BE EXPOSED TO PAHs? PAHs are found throughout our environment in the air, water, and soil, and can persist in the environment for months or years. PAHs occur naturally in coal, crude oil, gasoline, coal-tar pitch, creosote, and asphalt. When coal is converted to natural gas, PAHs can be released. PAHs are also produced during the incomplete combustion of fossil fuels, garbage, or other organic substances. The less efficient the burning process, the more PAHs are given off. Forest fires and volcanoes produce PAHs naturally. Levels of PAHs in urban air may be 10 times greater than those found in rural areas ...
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studyguide19-22
University of Florida , ESC 1000
Excerpt: ... Oct 22): What is life, what does it require, and how do we recognize it? What are the main features of Mars? How was Mars different earlier in its history than the planet we see today, and what are the implications of this for past life on Mars? Pay special attention to the evidence of the past nature of Mars. What is the nature (i.e., rock type) of Martian meteorites, and how do we know that they are Martian? Know the main features of meteorite ALH84001. What evidence did Kay et al. present to suggest evidence for fossil life in ALH84001, and what are the arguments against this evidence? Vocabulary: Valles Marineris, Tharsis Graben, Hesperia Planum Ridges, Olympus Mons, SNC, polycyclic aromatic hydrocarbon (PAH) ...
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Bio3440Study questionsJan2009
Laurentian, BIOL 200901
Excerpt: ... BIO3440Spring2009 Topic/Themefortheoralpresentations: ThefateandeffectsofPolycyclicAromaticHydrocarbons(PAHs) Studyquestions,Jan2009 1. WhowasParacelsus 2. DefineFDA,USEPA 3. WhathappenedinMinamata? 4. DefineLC50 5. Describe(inpointform)aprotocol ...
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Study_Guide_3
Washington, PSII 101
Excerpt: ... Study Guide 3: Concepts to know well for Exam 3 in Psychology 101 You are responsible for all lectures, as well as: Chapter 12, all Chapter 11 (375-381 only) Chapter 13 (453-488 only) Chapter 6, all Chapter 14 (535-537 only) Teratogens (e.g., fetal alcohol syndrome, ionizing radiation, non-ionizing radiation, Polycyclic Aromatic Hydorcarbons) Nongenetic familial intergenerational effects (glucose metabolism as presented in lecture, DES, handling of pregnant rats) Prenatal stages (zygote, embryo, fetus), Postnatal stages (infancy, childhood, adolescence, adulthood) Piaget's stages (what they are called, their order, and their characteristics) Schema formation (assimilation & accommodation) Object permanence Egocentrism Conservation Stranger anxiety Attachment (secure, anxious resistant, anxious avoidant) Separation anxiety Child rearing and the experience of choice, parenting (authoritative, authoritarian, permissive, rejectionneglect) Kohlberg's three basic levels (preconventional, conventional, postconventio ...
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Study_Guide_3
Washington, PSII 101
Excerpt: ... Study Guide 3: Concepts to know well for Exam 3 in Psychology 101 You are responsible for all lectures, as well as: Chapter 12, all Chapter 11 (375-381 only) Chapter 13 (453-488 only) Chapter 6, all Chapter 14 (535-537 only) Teratogens (e.g., fetal alcohol syndrome, ionizing radiation, non-ionizing radiation, Polycyclic Aromatic Hydorcarbons) Nongenetic familial intergenerational effects (glucose metabolism as presented in lecture, DES, handling of pregnant rats) Prenatal stages (zygote, embryo, fetus), Postnatal stages (infancy, childhood, adolescence, adulthood) Piaget's stages (what they are called, their order, and their characteristics) Schema formation (assimilation & accommodation) Object permanence Egocentrism Conservation Stranger anxiety Attachment (secure, anxious resistant, anxious avoidant) Separation anxiety Child rearing and the experience of choice, parenting (authoritative, authoritarian, permissive, rejectionneglect) Kohlberg's three basic levels (preconventional, conventional, postconventio ...
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biodiesel emissions
Oregon State, CHE 414
Excerpt: ... BIODIESEL EMISSIONS Biodiesel is the first and only alternative fuel to have a complete evaluation of emission results and potential health effects submitted to the U.S. Environmental Protection Agency (EPA) under the Clean Air Act Section 211(b). These programs include the most stringent emissions testing protocols ever required by EPA for certification of fuels or fuel additives. The data gathered complete the most thorough inventory of the environmental and human health effects attributes that current technology will allow. EPA has surveyed the large body of biodiesel emissions studies and averaged the Health Effects testing results with other major studies. The results are seen in the table below. AVERAGE BIODIESEL EMISSIONS COMPARED TO CONVENTIONAL DIESEL, ACCORDING TO EPA Emission Type Regulated Total Unburned Hydrocarbons Carbon Monoxide Particulate Matter Nox Non-Regulated Sulfates PAH ( Polycyclic Aromatic Hydrocarbons)* nPAH (nitrated PAHs)* Ozone potential of speciated HC * Estimated from B100 ...
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salama2
UNLV, PHYSICS 2
Excerpt: ... Computational Spectroscopy of Polycyclic Aromatic Hydrocarbons In Support of Laboratory Astrophysics Xiaofeng Tan Farid Salama February 3, 2006 Abstract Polycyclic aromatic hydrocarbons (PAHs) are strong candidates for the molecular carriers of the unidentied infrared bands (UIR) and the diuse interstellar bands (DIBs). In order to test the PAH hypothesis, we have systematically measured the vibronic spectra of a number of jetcooled neutral and ionized PAHs in the near ultraviolet (UV) to visible spectral ranges using the cavity ring-down spectroscopy. To support this experimental eort, we have carried out theoretical studies of the spectra obtained in our measurements. Ab initio and (time-dependent) density functional theory calculations are performed to obtain the geometries, energetics, vibrational frequencies, transition dipole moments, and normal coordinates of these PAH molecules. Franck(Condon (FC) calculations and/or vibronic calculations are then performed using the calculated normal ...
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farwell
W. Alabama, BIOL 499
Excerpt: ... Biology 499 - Senior Honours Projects Dr. Andrea J. Farwell afarwell@sciborg.uwaterloo.ca Office: B2 148 Ext. 3613 My current research interests include aquatic ecology and toxicology studies related to natural or anthropogenic organic compounds associated with the mining of oil sands. Oil sands constituents, specifically, naphthenic acids and polycyclic aromatic hydrocarbons represent complex mixtures of chemicals that vary in terms of degradation and toxicity. Recent studies have used stable isotopes to trace the exposure of fish and invertebrates to oil sands constituents in naturally eroded environments and in areas of anthropogenic activities within the Athabasca River drainage basin. Current laboratory studies focus on tracing the microbial degradation of these chemical groups using stable isotopes. There are Biol 499 laboratory opportunities to examine carbon/nitrogen pathways for primary producers and secondary consumers associated with exposure to oil sands constituents in the sediment/water. Other ...
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Aromaticity worksheet
Michigan, C 226
Excerpt: ... AROMATICITY AND AROMATIC SUBSTITUTION WORKSHEET Write a set of resonance structures for the intermediate of electrophilic nitration of methyl benzoate. HINT: the substitution occurs meta to the ester group. CO2CH3 NO2+ The structure of [12]annulene is shown to the right. Would you expect [12]annulene to be aromatic? Why or why not? Identify a source of transannular strain in [12]annulene. Complete the proton transfer reaction of imidazole, a heterocyclic aromatic compound, with a structure for its conjugate acid. H N N imidazole +H+ The carbon skeleton of pyrene, a polycyclic aromatic hydrocarbon obtained from coal tar, is shown to the right. Provide two Kekule structures for pyrene to show that it is aromatic. The structure to the left has been started for you. Complete the following organic reactions with structures for the reactant, product, or reagent as required. Note: some of these problems require knowledge of the directing power of the substituent(s) on the ring. NO2 HNO3 H2SO4 CH3 pKa = ...
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226Wi06 OL3
Michigan, C 226
Excerpt: ... CHEMISTRY 226, WINTER 2006 LECTURE OUTLINE #3 WEEK OF JANUARY 23, 2006 B. Aromaticity (continued) 3. The Hckel Rule for organic ions a. 4n + 2 cations b. 4n + 2 anions 4. Heterocyclic aromatic compounds 5. Polycyclic aromatic hydrocarbons (PAH's) C. Benzylic reactivity (quick survey) 1. Benzylic C-H bond 2. Benzylic oxidation 3. Benzylic halides in substitution reactions II. Reactivity of the Aromatic Ring A. Electrophilic aromatic substitution 1. General mechanistic considerations a. The two-step mechanism b. Nature of the cyclohexadienyl cation intermediate 2. Specific aromatic substitution reactions a. Nitration i. examples ii. mechanistic details b. Halogenation i. examples ii. mechanistic details c. Sulfonation and chlorosulfonation d. Carbon electrophiles i. the Friedel-Crafts alkylation reaction ii. the Friedel-Crafts acylation reaction iii. comparison of alkylation and acylation B. Reactivity and Orientation in Electiophilic Aromatic Substitution 1. Experimental data on rates and orientation End of ...
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Lec27-110104
Arizona, GIACALONE 206
Excerpt: ... f the impact which ejected them into space. Gas bubbles trapped in one meteorite, EETA79001, have a composition which matches the current Martian atmosphere Names after the first 3 places where they were found PTYS/ASTR 206 Mars IV: Life 11/01/04 ALH84001 timeline 4.5 Billion years ago - The original igneous rock solidified within Mars 3.6 - 4 billion years ago - the rock was fractured. Water then permeated the cracks, depositing carbonate minerals and allowing primitive bacteria to live in the fractures. 3.6 billion years ago - the bacteria and their by-products became fossilized in the fractures. 16 million years ago - a large meteorite struck Mars, dislodging a large chunk of this rock and ejecting it into space. 13,000 years ago - the meteorite landed in Antarctica, where it was discovered in 1984 PTYS/ASTR 206 Mars IV: Life 11/01/04 The Story of ALH84001 polycyclic aromatic hydrocarbons (PAHs) on the fracture surfaces Simple organic compounds PTYS/ASTR 206 Mars IV: Life 11/01/04 Th ...
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IM13
Laurentian, CHEM 200203
Excerpt: ... Explore Your World: Polymers and Recycling Plastics Aromatic Compounds Health Note: Aromatic Compounds in Health and Medicine Health Note: Polycyclic Aromatic Hydrocarbons (PAHs) Properties of Aromatic Compounds 13.3 13.4 13.5 13.6 13.7 Chapter Summary and Demonstrations 1. Functional Groups The concept of functional groups is introduced. The IUPAC system and some common names are used to describe the nomenclature of alkenes and alkynes as unsaturated compounds. The cis-trans isomers and their name of alkenes are described. 2. Reactions of Alkenes The reactive nature of unsaturated compounds is shown in the reactions, catalysts, and products of hydrogenation, hydrohalogenation, halogenation and hydration. Special interest topics include the chlorinated hydrocarbons used as pesticides, saturated and unsaturated fatty acids, and commercial uses of hydrogenation, polymers, and fused benzene rings in carcinogens. Demonstration: Hold a spoon over the flame of a candle. What substance forms on the spoon that ...
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P450_StarBiochem
Washington University in St. Louis, BIO 5924
Excerpt: ... ser Guide, p. 2. 8. Each of the menu bars on the right can be expanded by clicking on the arrow at the right of the bar. The menu bars are described in the User Guide p. 3-5. First, expand the Structure bar, select the Secondary tab, and check the All Ribbons box to veiw the secondary structure of the protein. 9. As you rotate the protein, you should see the backbone of the protein is in ribbon form and the amino acid side chains are extending from the backbone in stick form, color blue. This structure was solved as a dimer, so there are two identical proteins bound together. The yellow stick molecules are the heme and the substrate warfarin (which is an example of a polycyclic aromatic hydrocarbon PAH). The two chains of the dimers are called, Chain A and B. The substrate is labeled, SWF and the heme is labeled, HEC. 10. Next select the PDB Tree bar. Open the 1OG5 folder and click on SWF to select warfarin. 11. Go to the View Controls bar. Check the Draw box under Atoms. The box for Draw Bond ...
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lec3_1020_sjuh
GA Southern, ASTR 1020
Excerpt: ... . Sarah Higdon 34 -# Lecture 3 Polycyclic Aromatic Hydrocarbons - PAH Very Important Astronomically. Found in many objects : Comets to Starburst Galaxies. 15 % of interstellar carbon Polycyclic - Carbon Rings - Note Benzene has only 1 ring so not really poly-cyclic! Aromatic - really! Hydrocarbon made of Hydrogen and Carbon Lec 3: Prof. Sarah Higdon 35 Snake biting its tail. The electrons float above and below the ring, and the electromagnetic fields they generate keep the ring flat. Lec 3: Prof. Sarah Higdon 36 -# Lecture 3 Lec 3: Prof. Sarah Higdon 37 Poly-Cyclic Aromatic Hydrocarbons: Complex molecules in the Infrared Lec 3: Prof. Sarah Higdon 38 -# Lecture 3 True or False: 1. If I add more H-atoms to the glass tube and shoot high-speed electrons at them, will the spectral lines change? 2. If I replace the H-atoms with Helium atoms, will the spectral lines change? 3. An electron moves to a higher energy level in an atom after emitting a photon. 4. The energy of a ph ...
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226Wi09 OL02
Michigan, C 226
Excerpt: ... f the six pi molecular orbitals b. Electron delocalization in benzene c. Experimental evidence of electron delocalization B. Aromaticity 1. The Hckel rule: aromaticity and antiaromaticity 2. Examples illustrating the Hckel rule a. Neutral 4n + 2 molecules b. Neutral 4n molecules 3. The Hckel Rule for organic ions a. 4n + 2 cations b. 4n + 2 anions 4. Heterocyclic aromatic compounds 5. Polycyclic aromatic hydrocarbons (PAH's) ...
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chem201_molec_spec_lab
Hudson VCC, CHEM 201
Excerpt: ... Chem 201 DE Matthews Spring 2007 page 1 1/29/2007 chem201_molec_spec_lab.doc Molecular Spectroscopy of Polycyclic Aromatic Hydrocarbons (PAHs) Introduction This is a two-part experiment exploring various aspects of the molecular behavior of polycyclic aromatic hydrocarbons (PARs) in solution. In one part you will use UV-visible absorption, fluorescence and IR spectroscopy to investigate the relationship between vibrations in anthracenes ground electronic state and in its first excited state. First, you will obtain the UV-visible spectrum of anthracene to define the absorption bands. The result allows you to choose an excitation wavelength with which you will obtain the fluorescence emission spectrum. Now choosing one of the fluorescence peaks, you will measure its fluorescence excitation spectrum, and ascertain its similarity to the absorption spectrum. You will also measure its IR vibrational spectrum. In analyzing the photophysical features of anthracene, the vibronic spacings of anthracenes emissio ...
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page19_9
Maryville MO, PAGE 19
Excerpt: ... Dissolved Oxygen Saturation Controls PAH Biodegradation in Freshwater Estuary Sediments T.J. Boyd1, M.T. Montgomery1, J.K. Steele2, J.W. Pohlman2, S.R. Reatherford2, B.J. Spargo1 and D.C. Smith3 (1) Code 6114, U.S. Naval Research Laboratory, 4555 Overlook Ave, Washington, DC 20375, USA (2) Geo-Centers, Inc., PO Box 441340, Fort Washington, MD 20749, USA (3) Graduate School of Oceanography, University of Rhode Island, Narragansett, RI 02882, USA Received: 19 December 2003 / Accepted: 13 February 2004 / Online publication: Abstract Polycyclic aromatic hydrocarbons (PAHs) are common contaminants in terrestrial and aquatic environments and can represent a signicant constituent of the carbon pool in coastal sediments. We report here the results of an 18month seasonal study of PAH biodegradation and heterotrophic bacterial production and their controlling biogeochemical factors from 186 sediment samples taken in a tidally inuenced freshwater estuary. For each sampling event, measurements were averaged from ...
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lec29Mar10am
RPI, ASTR 2050
Excerpt: ... his part of the spectrum and are assigned to arom Infrared spectra of a late stage red giant (HR 4049) and planetary nebulae. Emission from 20-100 C atom polycyclic aromatic hydrocarbons (PAHs) are shown in red. This tells us about the composition, size, and temperature of grains. See also Kutner Fig.14.7 15 Dust grain concepts Key point: The grain size, relative to the wavelength, determines extinction. See also Kutner Fig.14.8 16 Blocking light with dust grains Dust is only 1% of the mass of the ISM, but remember our old discussion about 0! =0.5 c 1yr 18 =0.5 10 cm 6 3 12 3 n=1/10 m = 10 /cm 2 7 2 !(3m) = 10 cm n ! 0.05 !1/2 Light Year 17 In other words, for these values, 5% of the light with wavelength below 3 microns is blocked. Atomic and Molecular Gas Free atoms and (small) molecules Some important components: Hot (ionized) hydrogen gas (H-II) Cold (atomic) hydrogen gas (H-1) Cold molecular hydrogen (H2) Othe ...
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hw1_redo
Mt. Marty, PH 2610
Excerpt: ... Name _ PH2610D HOMEWORK 1 REDO Due: September 28,2000 Answer the following question sets. Answers should be typed. 1. Based on the article: Martinez-Frias ML, et al. Exploratory case-control study on maternal occupation as cook during pregnancy an ...
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