WorldWideScience

Sample records for photodissociation chemistry footprints

  1. The effects of polycyclic aromatic hydrocarbons on the chemistry of photodissociation regions

    NARCIS (Netherlands)

    Bakes, ELO; Tielens, AGGM

    1998-01-01

    We have investigated the effects of including polycylic aromatic hydrocarbons (PAHs) on the abundance of neutral atoms and molecules for two typical photodissociation regions (PDRs): a high-density case (the Orion complex) and a low-density case. PAHs provide a large surface area for chemistry

  2. Photodissociation of quantum state-selected diatomic molecules yields new insight into ultracold chemistry

    Science.gov (United States)

    McDonald, Mickey; McGuyer, Bart H.; Lee, Chih-Hsi; Apfelbeck, Florian; Zelevinsky, Tanya

    2016-05-01

    When a molecule is subjected to a sufficiently energetic photon it can break apart into fragments through a process called ``photodissociation''. For over 70 years this simple chemical reaction has served as a vital experimental tool for acquiring information about molecular structure, since the character of the photodissociative transition can be inferred by measuring the 3D photofragment angular distribution (PAD). While theoretical understanding of this process has gradually evolved from classical considerations to a fully quantum approach, experiments to date have not yet revealed the full quantum nature of this process. In my talk I will describe recent experiments involving the photodissociation of ultracold, optical lattice-trapped, and fully quantum state-resolved 88Sr2 molecules. Optical absorption images of the PADs produced in these experiments reveal features which are inherently quantum mechanical in nature, such as matter-wave interference between output channels, and are sensitive to the quantum statistics of the molecular wavefunctions. The results of these experiments cannot be predicted using quasiclassical methods. Instead, we describe our results with a fully quantum mechanical model yielding new intuition about ultracold chemistry.

  3. Radical Rearrangement Chemistry in Ultraviolet Photodissociation of Iodotyrosine Systems: Insights from Metastable Dissociation, Infrared Ion Spectroscopy, and Reaction Pathway Calculations.

    Science.gov (United States)

    Ranka, Karnamohit; Zhao, Ning; Yu, Long; Stanton, John F; Polfer, Nicolas C

    2018-05-29

    We report on the ultraviolet photodissociation (UVPD) chemistry of protonated tyrosine, iodotyrosine, and diiodotyrosine. Distonic loss of the iodine creates a high-energy radical at the aromatic ring that engages in hydrogen/proton rearrangement chemistry. Based on UVPD kinetics measurements, the appearance of this radical is coincident with the UV irradiation pulse (8 ns). Conversely, sequential UVPD product ions exhibit metastable decay on ca. 100 ns timescales. Infrared ion spectroscopy is capable of confirming putative structures of the rearrangement products as proton transfers from the imine and β-carbon hydrogens. Potential energy surfaces for the various reaction pathways indicate that the rearrangement chemistry is highly complex, compatible with a cascade of rearrangements, and that there is no preferred rearrangement pathway even in small molecular systems like these. Graphical Abstract.

  4. Atomic carbon emission from photodissociation of CO2. [planetary atmospheric chemistry

    Science.gov (United States)

    Wu, C. Y. R.; Phillips, E.; Lee, L. C.; Judge, D. L.

    1978-01-01

    Atomic carbon fluorescence, C I 1561, 1657, and 1931 A, has been observed from photodissociation of CO2, and the production cross sections have been measured. A line emission source provided the primary photons at wavelengths from threshold to 420 A. The present results suggest that the excited carbon atoms are produced by total dissociation of CO2 into three atoms. The cross sections for producing the O I 1304-A fluorescence through photodissociation of CO2 are found to be less than 0.01 Mb in the wavelength region from 420 to 835 A. The present data have implications with respect to photochemical processes in the atmospheres of Mars and Venus.

  5. Half collisions by photodissociation

    International Nuclear Information System (INIS)

    Vries, M.S. de.

    1980-01-01

    The photodissociation of ICl, IBr and TlBr is studied. In the case of ICl and IBr, experiments are reported at various wavelengths between 480 and 530 nm. For TlBr, photodissociation for a range of wavelengths between 264 and 268 nm is reported. (Auth.)

  6. Tracing footprints of environmental events in tree ring chemistry using neutron activation analysis

    Science.gov (United States)

    Sahin, Dagistan

    The aim of this study is to identify environmental effects on tree-ring chemistry. It is known that industrial pollution, volcanic eruptions, dust storms, acid rain and similar events can cause substantial changes in soil chemistry. Establishing whether a particular group of trees is sensitive to these changes in soil environment and registers them in the elemental chemistry of contemporary growth rings is the over-riding goal of any Dendrochemistry research. In this study, elemental concentrations were measured in tree-ring samples of absolutely dated eleven modern forest trees, grown in the Mediterranean region, Turkey, collected and dated by the Malcolm and Carolyn Wiener Laboratory for Aegean and Near Eastern Dendrochronology laboratory at Cornell University. Correlations between measured elemental concentrations in the tree-ring samples were analyzed using statistical tests to answer two questions. Does the current concentration of a particular element depend on any other element within the tree? And, are there any elements showing correlated abnormal concentration changes across the majority of the trees? Based on the detailed analysis results, the low mobility of sodium and bromine, positive correlations between calcium, zinc and manganese, positive correlations between trace elements lanthanum, samarium, antimony, and gold within tree-rings were recognized. Moreover, zinc, lanthanum, samarium and bromine showed strong, positive correlations among the trees and were identified as possible environmental signature elements. New Dendrochemistry information found in this study would be also useful in explaining tree physiology and elemental chemistry in Pinus nigra species grown in Turkey. Elemental concentrations in tree-ring samples were measured using Neutron Activation Analysis (NAA) at the Pennsylvania State University Radiation Science and Engineering Center (RSEC). Through this study, advanced methodologies for methodological, computational and

  7. High-throughput bioconjugation for enhanced 193 nm photodissociation via droplet phase initiated ion/ion chemistry using a front-end dual spray reactor.

    Science.gov (United States)

    Cotham, Victoria C; Shaw, Jared B; Brodbelt, Jennifer S

    2015-09-15

    Fast online chemical derivatization of peptides with an aromatic label for enhanced 193 nm ultraviolet photodissociation (UVPD) is demonstrated using a dual electrospray reactor implemented on the front-end of a linear ion trap (LIT) mass spectrometer. The reactor facilitates the intersection of protonated peptides with a second population of chromogenic 4-formyl-1,3-benzenedisulfonic acid (FBDSA) anions to promote real-time formation of ion/ion complexes at atmospheric pressure. Subsequent collisional activation of the ion/ion intermediate results in Schiff base formation generated via reaction between a primary amine in the peptide cation and the aldehyde moiety of the FBDSA anion. Utilizing 193 nm UVPD as the subsequent activation step in the MS(3) workflow results in acquisition of greater primary sequence information relative to conventional collision induced dissociation (CID). Furthermore, Schiff-base-modified peptides exhibit on average a 20% increase in UVPD efficiency compared to their unmodified counterparts. Due to the efficiency of covalent labeling achieved with the dual spray reactor, we demonstrate that this strategy can be integrated into a high-throughput LC-MS(n) workflow for rapid derivatization of peptide mixtures.

  8. Spin-State-Controlled Photodissociation of Iron(III) Azide to an Iron(V) Nitride Complex

    Czech Academy of Sciences Publication Activity Database

    Andris, E.; Navrátil, R.; Jašík, J.; Sabenya, G.; Costas, M.; Srnec, Martin; Roithová, J.

    2017-01-01

    Roč. 56, č. 45 (2017), s. 14057-14060 ISSN 1521-3773 Institutional support: RVO:61388955 Keywords : Ion spectroscopy * Iron(V) nitride * Photodissociation Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry

  9. Iron monoxide photodissociation

    Science.gov (United States)

    Chestakov, D. A.; Parker, D. H.; Baklanov, A. V.

    2005-02-01

    The photodissociation of Fe56O was studied by means of the velocity map imaging technique. A molecular beam of iron atoms and iron monoxide molecules was created using an electrical discharge with an iron electrode in a supersonic expansion of molecular oxygen. The ground state iron atom Fe(D45) and FeO concentrations in the molecular beam have been estimated. The dissociation energy of the FeO XΔ5 ground electronic state was found to be D00(FeO )=4.18±0.01eV. The effective absorption cross section of FeO at 252.39nm (vac), leading to the Fe(D45)+O(P3) dissociation channel, is ˜1.2×10-18cm2. A (1+1) resonantly enhanced multiphoton ionization spectrum of Fe56O in the region 39550-39580 cm-1 with rotational structure has been observed, but not assigned. Angular distributions of Fe(D45) and Fe(D35) products for the channel FeO →Fe(D4,35)+O(P3) have been measured at several points in the 210-260nm laser light wavelength region. The anisotropy parameter varies strongly with wavelength for both channels.

  10. Detection of Indistinct Fe-N Stretching Bands in Iron(V) Nitrides by Photodissociation Spectroscopy

    Czech Academy of Sciences Publication Activity Database

    Andris, E.; Navrátil, R.; Jašík, J.; Sabenya, G.; Costas, M.; Srnec, Martin; Roithová, J.

    2018-01-01

    Roč. 24, č. 20 (2018), s. 5078-5081 ISSN 1521-3765 R&D Projects: GA ČR(CZ) GJ15-10279Y Institutional support: RVO:61388955 Keywords : photodissociation spectrochemistry * infrared spectra * DFT Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry

  11. Photodissociation of ultracold diatomic strontium molecules with quantum state control.

    Science.gov (United States)

    McDonald, M; McGuyer, B H; Apfelbeck, F; Lee, C-H; Majewska, I; Moszynski, R; Zelevinsky, T

    2016-07-07

    Chemical reactions at ultracold temperatures are expected to be dominated by quantum mechanical effects. Although progress towards ultracold chemistry has been made through atomic photoassociation, Feshbach resonances and bimolecular collisions, these approaches have been limited by imperfect quantum state selectivity. In particular, attaining complete control of the ground or excited continuum quantum states has remained a challenge. Here we achieve this control using photodissociation, an approach that encodes a wealth of information in the angular distribution of outgoing fragments. By photodissociating ultracold (88)Sr2 molecules with full control of the low-energy continuum, we access the quantum regime of ultracold chemistry, observing resonant and nonresonant barrier tunnelling, matter-wave interference of reaction products and forbidden reaction pathways. Our results illustrate the failure of the traditional quasiclassical model of photodissociation and instead are accurately described by a quantum mechanical model. The experimental ability to produce well-defined quantum continuum states at low energies will enable high-precision studies of long-range molecular potentials for which accurate quantum chemistry models are unavailable, and may serve as a source of entangled states and coherent matter waves for a wide range of experiments in quantum optics.

  12. Photodissociation and excitation of interstellar molecules

    International Nuclear Information System (INIS)

    Dishoeck, E.F. van.

    1984-01-01

    Apart from a rather long introduction containing some elementary astrophysics, quantum chemistry and spectroscopy and an incomplete, historical review of molecular observations, this thesis is divided into three sections. In part A, a rigorous quantum chemical and dynamical study is made of the photodissociation processes in the OH and HCl molecules. In part B, the cross sections obtained in part A are used in various astrophysical problems such as the study of the abundances of the OH and HCl molecules in interstellar clouds, the use of the OH abundance as a measure of the cosmic ray ionization rate, the lifetime of the OH radical in comets and the abundance of OH in the solar photosphere. Part C discusses the excitation of the C 2 molecule under interstellar conditions, its use as a diagnostic probe of the temperature, density and strength of the radiation field in interstellar clouds. Quadrupole moments and oscillator strengths are analyzed. (Auth.)

  13. Fast beam studies of free radical photodissociation

    Energy Technology Data Exchange (ETDEWEB)

    Neumark, D.M. [Lawrence Berkeley Laboratory, CA (United States)

    1993-12-01

    The authors have developed a novel technique for studying the photodissociation spectroscopy and dynamics of free radicals. In these experiments, radicals are generated by laser photodetachment of a fast (6-8 keV) mass-selected negative ion beam. The resulting radicals are photodissociated with a second laser, and the photofragments are collected and detected with high efficiency using a microchannel plate detector. The overall process is: ABC{sup -} {yields} ABC + e{sup -} {yields} A + BC, AB + C. Two types of fragment detection schemes are used. To map out the photodissociation cross-section of the radical, the photodissociation laser is scanned and the total photofragment yield is measured as a function of wavelength. In other experiments, the photodissociation frequency is fixed and the photofragment masses, kinetic energy release, and scattering angle is determined for each photodissociation event.

  14. Vector properties in molecular photodissociation

    International Nuclear Information System (INIS)

    Underwood, J.

    1999-12-01

    The technique of resonance enhanced multi-photon ionization (REMPI) of atomic and molecular species produced from a photofragmentation event combined with time-of flight (TOF) detection is used to examine scalar and vector properties following photodissociation. This technique is applied to the study of methyl bromide dissociation in a product state specific manner. We report measurements of the angular distributions and kinetic energy releases of the resulting bromine atoms in the ground and first spin-orbit excited state. Additionally we report measurements of the angular distributions and kinetic energy releases of the methyl fragment in the ground vibrational state, and also the excited state with one quanta in the ν 2 vibrational modes. These studies were carried out in the red wing of the absorption band at several wavelengths. For these measurements we were able to resolve the spin orbit state of the partner bromine fragment. From our observations we find new evidence for enhanced nonadiabatic curve crossing active in methyl bromide dissociation in comparison with earlier studies of methyl iodide. The atomic polarization produced following photodissociation of a diatomic molecule was investigated both theoretically and experimentally. We develop theoretical expressions relating the lab frame and molecular frame atomic polarization to the photoexcitation and subsequent dissociation of a diatomic molecule. This treatment includes both incoherent, coherent and non-adiabatic processes which may be active in the photodissociation process. We treat the general case of a polarized diatomic molecule yielding two fragments with non zero angular momentum. Experimentally, an investigation of the polarization of atomic Cl( 2 P 3/2 ) photofragments from the ∼330 nm photolysis of molecular chlorine using the REMPI-TOF technique is reported. We present a theoretical framework in which to treat such experiments allowing the extraction of parameters with direct physical

  15. Photodissociation processes in molecular beams

    International Nuclear Information System (INIS)

    Carlson, L.R.

    1979-05-01

    A description is presented of a study of the photodissociation dynamics of molecules in a molecular beam. Photo-fragmentation translational spectroscopy has been utilized to observe the photodissociation dynamics of ozone. Using a supersonic molecular beam and a 10 nanosecond pulsed laser at lambda = 266 nm, the velocities of the fragment products are measured by the method of time of flight. The resolution of the time of flight spectrum of ozone is sufficiently high that the electronic and vibrational states are clearly resolved and identified. Above the threshold (lambda 1 D) has been estimated in the past to be unity for the process O 3 ( 1 A 1 ) + hν)lambda 3 ( 1 B 2 ) → O 2 ( 1 Δ/sub g/) + O( 1 D). However a small production of O 2 ( 3 Σ/sub g/ - ) + O( 3 P) has been observed in this study. The O 2 ( 1 Δ/sub g/) product yields four vibrational states (v = 0, 1, 2, 3) which yields a vibrational temperature of 2700 0 K along with narrow energy distributions of rotational levels. These energy distributions are compared with photodissociation models along with the polarization dependence of the dissociative process which was also measured. 143 references

  16. Photodissociation processes in molecular beams

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, L.R.

    1979-05-01

    A description is presented of a study of the photodissociation dynamics of molecules in a molecular beam. Photo-fragmentation translational spectroscopy has been utilized to observe the photodissociation dynamics of ozone. Using a supersonic molecular beam and a 10 nanosecond pulsed laser at lambda = 266 nm, the velocities of the fragment products are measured by the method of time of flight. The resolution of the time of flight spectrum of ozone is sufficiently high that the electronic and vibrational states are clearly resolved and identified. Above the threshold (lambda < 310 nm), the quantum yield for the production of O(/sup 1/D) has been estimated in the past to be unity for the process O/sub 3/ (/sup 1/A/sub 1/) + h..nu..)lambda < 300 nm) ..-->.. O/sub 3/(/sup 1/B/sub 2/) ..-->.. O/sub 2/(/sup 1/..delta../sub g/) + O(/sup 1/D). However a small production of O/sub 2/ (/sup 3/..sigma../sub g//sup -/) + O(/sup 3/P) has been observed in this study. The O/sub 2/(/sup 1/..delta../sub g/) product yields four vibrational states (v = 0, 1, 2, 3) which yields a vibrational temperature of 2700/sup 0/K along with narrow energy distributions of rotational levels. These energy distributions are compared with photodissociation models along with the polarization dependence of the dissociative process which was also measured. 143 references.

  17. Carbon Footprints

    OpenAIRE

    Rahel Aichele; Gabriel Felbermayr

    2011-01-01

    Lässt sich der Beitrag eines Landes zum weltweiten Klimaschutz an der Veränderung seines CO2-Ausstoßes messen, wie es im Kyoto-Abkommen implizit unterstellt wird? Oder ist aufgrund der Bedeutung des internationalen Güterhandels der Carbon Footprint – der alle CO2-Emissionen erfasst, die durch die Absorption (d.h. Konsum und Investitionen) eines Landes entstehen – das bessere Maß? Die Autoren erstellen eine Datenbank mit den Footprints von 40 Ländern für den Zeitraum 1995–2007. Die deskriptive...

  18. Imaging of rotational wave-function in photodissociation of rovibrationally excited HCl molecules

    Czech Academy of Sciences Publication Activity Database

    Grygoryeva, Kateřina; Rakovský, Jozef; Votava, Ondřej; Fárník, Michal

    2017-01-01

    Roč. 147, č. 1 (2017), č. článku 013901. ISSN 0021-9606 R&D Projects: GA ČR GA14-08937S; GA ČR GA13-11635S Institutional support: RVO:61388955 Keywords : Angular distribution * Chemical reactions * Photodissociation Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 2.965, year: 2016

  19. Eighteenth annual West Coast theoretical chemistry conference

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-05-01

    Abstracts are presented from the eighteenth annual west coast theoretical chemistry conference. Topics include molecular simulations; quasiclassical simulations of reactions; photodissociation reactions; molecular dynamics;interface studies; electronic structure; and semiclassical methods of reactive systems.

  20. Photoleucine Survives Backbone Cleavage by Electron Transfer Dissociation. A Near-UV Photodissociation and Infrared Multiphoton Dissociation Action Spectroscopy Study

    Czech Academy of Sciences Publication Activity Database

    Shaffer, C. J.; Martens, J.; Marek, Aleš; Oomens, J.; Tureček, F.

    2016-01-01

    Roč. 27, č. 7 (2016), s. 1176-1185 ISSN 1044-0305 Institutional support: RVO:61388963 Keywords : peptide ions * electron transfer dissociation * photoleucine label * near-UV photodissociation * infrared multiphoton dissociation action spectroscopy Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.786, year: 2016

  1. High power atomic iodine photodissociation lasers

    International Nuclear Information System (INIS)

    Palmer, R.E.; Padrick, T.D.; Jones, E.D.

    1976-01-01

    The atomic iodine photodissociation laser has developed into a system capable of producing nanosecond or shorter pulses of near infrared radiation with energies well in excess of a hundred J. Discussed are the operating characteristics, advantages, and potential problem areas associated with this laser

  2. Isotope separation by selective photodissociation of glyoxal

    International Nuclear Information System (INIS)

    Marling, J.B.

    1976-01-01

    Dissociation products, mainly formaldehyde and carbon monoxide, enriched in a desired isotope of carbon, oxygen, or hydrogen are obtained by the selective photodissociation of glyoxal wherein glyoxal is subjected to electromagnetic radiation in a predetermined wavelength such that photon absorption excites and induces dissociation of only those molecules of glyoxal containing the desired isotope

  3. Photodissociation and photoionization of organosulfur radicals

    International Nuclear Information System (INIS)

    Hsu, Chia-Wei.

    1994-01-01

    The dynamics of S( 3 P 2,1,0 , 1 D 2 ) production from the 193 nm photodissociation of CH 3 SCH 3 , H 2 S and CH 3 SH have been studied using 2 + 1 resonance-enhanced multiphoton ionization (REMPI) techniques. The 193 nm photodissociation cross sections for the formation of S from CH 3 S and HS initially prepared in the photodissociation of CH 3 SCH 3 and H 2 S are estimated to be 1 x 10 -18 and 1.1 x 10 -18 cm 2 , respectively. The dominant product from CH 3 S is S( 1 D), while that from SH is S( 3 P). Possible potential energy surfaces involved in the 193 nm photodissociation of CH 3 S(X) and SH(X) have been also examined. Threshold photoelectron (PE) spectra for SH and CH 3 S formed in the ultraviolet photodissociation of H 2 S and CH 3 SH, respectively, have been measured using the nonresonant two-photon pulsed field ionization (N2P-PFI) technique. The rotationally resolved N2P-PFI-PE spectrum obtained for SH indicates that photoionization dynamics favors the rotational angular momentum change ΔN 2 product 3,2 ) and CH 3 S(X 2 E 3/2 ) are determined to be 84,057.5 ± 3 cm -1 and 74,726 ± 8 cm -1 respectively. The spin-orbit splittings for SH(X 2 product 3/2,1/2 ) and CH 3 S(X 2 E 3/2,1/2 ) are found to be 377 ± 2 and 257 ± 5 cm -1 , respectively, in agreement with previous measurements. The C-S stretching frequency for CH 3 S + (X 3 A 2 ) is 733 ± 5 cm -1 . This study illustrates that the PFI-PE detection method can be a sensitive probe for the nascent internal energy distribution of photoproducts

  4. Gas phase ion chemistry

    CERN Document Server

    Bowers, Michael T

    1979-01-01

    Gas Phase Ion Chemistry, Volume 2 covers the advances in gas phase ion chemistry. The book discusses the stabilities of positive ions from equilibrium gas-phase basicity measurements; the experimental methods used to determine molecular electron affinities, specifically photoelectron spectroscopy, photodetachment spectroscopy, charge transfer, and collisional ionization; and the gas-phase acidity scale. The text also describes the basis of the technique of chemical ionization mass spectrometry; the energetics and mechanisms of unimolecular reactions of positive ions; and the photodissociation

  5. Photodissociation and charge transfer dynamics of negative ions studied with femtosecond photoelectron spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Zanni, Martin Thomas [Univ. of California, Berkeley, CA (United States)

    1999-12-01

    This dissertation presents studies aimed at understanding the potential energy surfaces and dynamics of isolated negative ions, and the effects of solvent on each. Although negative ions play important roles in atmospheric and solution phase chemistry, to a large extent the ground and excited state potential energy surfaces of gas phase negative ions are poorly characterized, and solvent effects even less well understood. In an effort to fill this gap, the author's coworkers and the author have developed a new technique, anion femtosecond photoelectron spectroscopy, and applied it to gas phase photodissociation and charge transfer processes. Studies are presented that (1) characterize the ground and excited states of isolated and clustered anions, (2) monitor the photodissociation dynamics of isolated and clustered anions, and (3) explore the charge-transfer-to-solvent states of atomic iodide clustered with polar and non-polar solvents.

  6. Photodissociation and charge transfer dynamics of negative ions studied with femtosecond photoelectron spectroscopy

    International Nuclear Information System (INIS)

    Zanni, Martin T.

    1999-01-01

    This dissertation presents studies aimed at understanding the potential energy surfaces and dynamics of isolated negative ions, and the effects of solvent on each. Although negative ions play important roles in atmospheric and solution phase chemistry, to a large extent the ground and excited state potential energy surfaces of gas phase negative ions are poorly characterized, and solvent effects even less well understood. In an effort to fill this gap, the author's coworkers and the author have developed a new technique, anion femtosecond photoelectron spectroscopy, and applied it to gas phase photodissociation and charge transfer processes. Studies are presented that (1) characterize the ground and excited states of isolated and clustered anions, (2) monitor the photodissociation dynamics of isolated and clustered anions, and (3) explore the charge-transfer-to-solvent states of atomic iodide clustered with polar and non-polar solvents

  7. Discrete variable theory of triatomic photodissociation

    International Nuclear Information System (INIS)

    Heather, R.W.; Light, J.C.

    1983-01-01

    The coupled equations describing the photodissociation process are expressed in the discrete variable representation (DVR) in which the coupled equations are labeled by quadrature points rather than by internal basis functions. A large reduction in the dimensionality of the coupled equations can be realized since the spatially localized bound state nuclear wave function vanishes at most of the quadrature points, making only certain orientations of the fragments important in the region of strong interaction (small separation). The discrete variable theory of photodissociation is applied to the model dissociation of bent HCN in which the CN fragment is treated as a rigid rotor. The truncated DVR rotational distributions are compared with the exact close coupled rotational distributions, and excellent agreement with greatly reduced dimensionality of the equations is found

  8. Photodissociation of CS from Excited Rovibrational Levels

    Science.gov (United States)

    Pattillo, R. J.; Cieszewski, R.; Stancil, P. C.; Forrey, R. C.; Babb, J. F.; McCann, J. F.; McLaughlin, B. M.

    2018-05-01

    Accurate photodissociation cross sections have been computed for transitions from the X 1Σ+ ground electronic state of CS to six low-lying excited electronic states. New ab initio potential curves and transition dipole moment functions have been obtained for these computations using the multi-reference configuration interaction approach with the Davidson correction (MRCI+Q) and aug-cc-pV6Z basis sets. State-resolved cross sections have been computed for transitions from nearly the full range of rovibrational levels of the X 1Σ+ state and for photon wavelengths ranging from 500 Å to threshold. Destruction of CS via predissociation in highly excited electronic states originating from the rovibrational ground state is found to be unimportant. Photodissociation cross sections are presented for temperatures in the range between 1000 and 10,000 K, where a Boltzmann distribution of initial rovibrational levels is assumed. Applications of the current computations to various astrophysical environments are briefly discussed focusing on photodissociation rates due to the standard interstellar and blackbody radiation fields.

  9. Chemistry

    International Nuclear Information System (INIS)

    Ferris, L.M.

    1975-01-01

    The chemical research and development efforts related to the design and ultimate operation of molten-salt breeder reactor systems are concentrated on fuel- and coolant-salt chemistry, including the development of analytical methods for use in these systems. The chemistry of tellurium in fuel salt is being studied to help elucidate the role of this element in the intergranular cracking of Hastelloy N. Studies were continued of the effect of oxygen-containing species on the equilibrium between dissolved UF 3 and dissolved UF 4 , and, in some cases, between the dissolved uranium fluorides and graphite, and the UC 2 . Several aspects of coolant-salt chemistry are under investigation. Hydroxy and oxy compounds that could be formed in molten NaBF 4 are being synthesized and characterized. Studies of the chemistry of chromium (III) compounds in fluoroborate melts were continued as part of a systematic investigation of the corrosion of structural alloys by coolant salt. An in-line voltammetric method for determining U 4+ /U 3+ ratios in fuel salt was tested in a forced-convection loop over a six-month period. (LK)

  10. Chemistry

    International Nuclear Information System (INIS)

    Ferris, L.M.

    1976-01-01

    Research progress is reported in programs on fuel-salt chemistry, properties of compounds in the Li--Te system, Te spectroscopy UF 4 --H equilibria, porous electrode studies of molten salts, fuel salt-coolant salt reactions, thermodynamic properties of transition-metal fluorides, and properties of sodium fluoroborate. Developmental work on analytical methods is summarized including in-line analysis of molten MSBR fuel, analysis of coolant-salts for tritium, analysis of molten LiF--BeF 2 --ThF 4 for Fe and analysis of LiF--BeF--ThF 4 for Te

  11. High-Resolution Photoionization, Photoelectron and Photodissociation Studies. Determination of Accurate Energetic and Spectroscopic Database for Combustion Radicals and Molecules

    Energy Technology Data Exchange (ETDEWEB)

    Ng, Cheuk-Yiu [Univ. of California, Davis, CA (United States)

    2016-04-25

    The main goal of this research program was to obtain accurate thermochemical and spectroscopic data, such as ionization energies (IEs), 0 K bond dissociation energies, 0 K heats of formation, and spectroscopic constants for radicals and molecules and their ions of relevance to combustion chemistry. Two unique, generally applicable vacuum ultraviolet (VUV) laser photoion-photoelectron apparatuses have been developed in our group, which have used for high-resolution photoionization, photoelectron, and photodissociation studies for many small molecules of combustion relevance.

  12. Casting Footprints for Eternity

    Science.gov (United States)

    1999-01-01

    Apollo 11 Astronaut Buzz Aldrin has his footprints casted during the dedication ceremony of the rocket fountain at Building 4200 at Marshall Space Flight Center. The casts of Aldrin's footprints will be placed in the newly constructed Von Braun courtyard representing the accomplishments of the Apollo 11 lunar landing.

  13. Isotope effects in gas-phase chemical reactions and photodissociation processes: Overview

    International Nuclear Information System (INIS)

    Kaye, J.A.

    1992-01-01

    The origins of isotope effects in equilibrium and non-equilibrium chemical processes are reviewed. In non-equilibrium processes, attention is given to isotope effects in simple bimolecular reactions, symmetry-related reactions, and photodissociation processes. Recent examples of isotope effects in these areas are reviewed. Some indication of other scientific areas for which measurements and/or calculations of isotope effects are used is also given. Examples presented focus on neutral molecule chemistry and in many cases complement examples considered in greater detail in the other chapters of this volume

  14. THE PHOTODISSOCIATION OF FORMALDEHYDE IN COMETS

    Energy Technology Data Exchange (ETDEWEB)

    Feldman, Paul D., E-mail: pfeldman@jhu.edu [Department of Physics and Astronomy, The Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218 (United States)

    2015-10-20

    Observations of comets in the 905–1180 Å spectral band made with the Far Ultraviolet Spectroscopic Explorer in 2001 and 2004 show unusual features in the fluorescent emissions of CO and H{sub 2}. These include emission from a non-thermal high-J rotational population of CO and solar Lyα induced fluorescence from excited vibrational levels of H{sub 2}, both of which are attributed to the photodissociation of formaldehyde. In this paper we model the large number of observed H{sub 2} lines and demonstrate the dependence of the pumping on the heliocentric velocity of the comet and the solar line profiles. We also derive the rotational and vibrational populations of H{sub 2} and show that they are consistent with the results of laboratory studies of the photodissociation of H{sub 2}CO. In addition to the principal series of H i and O i, the residual spectrum is found to consist mainly of the Rydberg series of C i multiplets from which we derive the mean carbon column abundance in the coma. Fluorescent emissions from N i and N{sub 2} are also searched for.

  15. Model of comet comae. II. Effects of solar photodissociative ionization

    International Nuclear Information System (INIS)

    Huebner, W.F.; Giguere, P.T.

    1980-01-01

    Improvements to our computer model of coma plotochemistry are described. These include an expansion of the chemical reactions network and new rate constants that have been measured only recently. Photolytic reactions of additional molecules are incorporated, and photolytic branching ratios are treated in far greater detail than in our previous work. A total of 25 photodissociative ionization (PDI) reactions are now considered (as compared to only 3 PDI reactions previously). Solar PDI of the mother molecule CO 2 is shown to compete effectively with photoionization of CO in the production of observed CO + . The CO + density peak predicted by our improved model, for COP 2 or CO mother molecules, is deep in the inner coma, in better agreement with observation than our old CO 2 model. However, neither CO 2 nor CO mother molecule calculations reproduce the CO + /H 2 O + ratio observed in comet Kohoutek. PDI products of CO 2 , CO, CH 4 , and NH 3 mother molecules fuel a complex chemistry scheme, producing inner coma abundances of CN, C 2 , and C 3 much greater than previously calculated

  16. Sensitivity of the photodissociation of NO2, NO3, HNO3 and H2O2 to the solar radiation diffused by the ground and by atmospheric particles

    International Nuclear Information System (INIS)

    Mugnai, A.; Petroncelli, P.; Fiocco, G.

    1979-01-01

    The diffusion of solar radiation by atmospheric molecules and aerosols and by ground albedo affects the photodissociation rates of atmospheric species relevant to the ozone chemistry. In this paper, a previous investigation on the photodissociation of O 3 is extended to NO 2 , NO 3 , HNO 3 , H 2 O 2 . Because of the different character of the absorption spectra of these species, the behaviour of photodissociation profiles with height and their sensitivity to such factors as ground albedo, aerosol loads, solar zenith angle are somewhat different. The results show that the presence of the aerosols usually enhances the photodissociation in the upper troposphere and in the stratosphere, because of scattering, but tends to reduce it at low heights because of the increased extinction. Enhancements in the photodissociation coefficients are as high as 20 to 40% for low values of the albedo and large aerosol loads such as those obtained after a volcanic eruption. On the other hand, at large values of the albedo, the effect of aerosols is mainly in attenuating the radiation going into and coming from the ground and their presence can lead to reduced photolysis even in the stratosphere. (author)

  17. Photo-dissociation of hydrogen passivated dopants in gallium arsenide

    International Nuclear Information System (INIS)

    Tong, L.; Larsson, J.A.; Nolan, M.; Murtagh, M.; Greer, J.C.; Barbe, M.; Bailly, F.; Chevallier, J.; Silvestre, F.S.; Loridant-Bernard, D.; Constant, E.; Constant, F.M.

    2002-01-01

    A theoretical and experimental study of the photo-dissociation mechanisms of hydrogen passivated n- and p-type dopants in gallium arsenide is presented. The photo-induced dissociation of the Si Ga -H complex has been observed for relatively low photon energies (3.48 eV), whereas the photo-dissociation of C As -H is not observed for photon energies up to 5.58 eV. This fundamental difference in the photo-dissociation behavior between the two dopants is explained in terms of the localized excitation energies about the Si-H and C-H bonds

  18. Chemistry

    International Nuclear Information System (INIS)

    Ferris, L.M.

    1975-01-01

    Research and development activities dealing with the chemical problems related to design and ultimate operation of molten-salt reactor systems are described. An experimental test stand was constructed to expose metallurgical test specimens to Te 2 vapor at defined temperatures and deposition rates. To better define the chemistry of fluoroborate coolant, several aspects are being investigated. The behavior of hydroxy and oxy compounds in molten NaBF 4 is being investigated to define reactions and compounds that may be involved in corrosion and/or could be involved in methods for trapping tritium. Two corrosion products of Hastelloy N, Na 3 CrF 6 and Na 5 Cr 3 F 14 , were identified from fluoroborate systems. The evaluation of fluoroborate and alternate coolants continued. Research on the behavior of hydrogen and its isotopes is summarized. The solubilities of hydrogen, deuterium, and helium in Li 2 BeF 4 are very low. The sorption of tritium on graphite was found to be significant (a few milligrams of tritium per kilogram of graphite), possibly providing a means of sequestering a portion of the tritium produced. Development of analytical methods continued with emphasis on voltammetric and spectrophotometric techniques for the in-line analysis of corrosion products such as Fe 2+ and Cr 3+ and the determination of the U 3+ /U 4+ ratio in MSBR fuel salt. Similar studies were conducted with the NaBF 4 --NaF coolant salt. Information developed during the previous operation of the CSTF has been assessed and used to formulate plans for evaluation of in-line analytical methods in future CSTF operations. Electroanalytical and spectrophotometric research suggests that an electroactive protonic species is present in molten NaBF 4 --NaF, and that this species rapidly equilibrates with a volatile proton-containing species. Data obtained from the CSTF indicated that tritium was concentrated in the volatile species. (JGB)

  19. Photodissociation of spatially aligned acetaldehyde cations.

    Science.gov (United States)

    Lee, Suk Kyoung; Silva, Ruchira; Kim, Myung Hwa; Shen, Lei; Suits, Arthur G

    2007-07-26

    Photofragment translational energy and angular distributions are reported for the photodissociation of acetaldehyde cations in the wavelength range 354-363 nm obtained using the DC slice ion imaging technique. Vibrationally selected parent ions were produced by 2+1 resonance-enhanced multiphoton ionization (REMPI) via the 3sCH3CO+, and CH4+. The angular distributions reveal that all product channels have a predominantly parallel recoil anisotropy although the lower beta2 parameter of CH3CO+ indicates the concomitant presence of a perpendicular component. Furthermore, the distinct angular distribution of the CH3CO+ fragments shows a large value of the higher order Legendre polynomial term, providing evidence that acetaldehyde cations are spatially aligned during the ionization process.

  20. Photodissociation spectroscopy of NbnArm complexes

    International Nuclear Information System (INIS)

    Menezes, W.J.C.; Knickelbein, M.B.

    1993-01-01

    The optical absorption spectra of niobium clusters containing 7 to 20 atoms have been measured from 336 to 634 nm by way of photodissociation action spectroscopy of the corresponding van der Waals complexes with argon atoms: Nb n Ar m → hν Nb n + m Ar. The clusters in this size range do not display discrete absorption bands characteristic of molecular behavior, but rather absorption cross sections which increase monotonically with decreasing wavelength. This behavior is in qualitative accord with the absorption behavior predicted by the spherical Mie model for small niobium spheres, however, the measured cross sections are 2--5 times larger than predicted over this wavelength range, with the smallest clusters displaying the largest deviations. Interpreted within the classical electrodynamic framework, these observations suggest that the absorption spectra derive oscillator strength from an incipient surface plasmon, redshifted from its predicted resonance frequency in the vacuum ultraviolet

  1. Ultraviolet photodissociation dynamics of the benzyl radical.

    Science.gov (United States)

    Song, Yu; Zheng, Xianfeng; Lucas, Michael; Zhang, Jingsong

    2011-05-14

    Ultraviolet (UV) photodissociation dynamics of jet-cooled benzyl radical via the 4(2)B(2) electronically excited state is studied in the photolysis wavelength region of 228 to 270 nm using high-n Rydberg atom time-of-flight (HRTOF) and resonance enhanced multiphoton ionization (REMPI) techniques. In this wavelength region, H-atom photofragment yield (PFY) spectra are obtained using ethylbenzene and benzyl chloride as the precursors of benzyl radical, and they have a broad peak centered around 254 nm and are in a good agreement with the previous UV absorption spectra of benzyl. The H + C(7)H(6) product translational energy distributions, P(E(T))s, are derived from the H-atom TOF spectra. The P(E(T)) distributions peak near 5.5 kcal mol(-1), and the fraction of average translational energy in the total excess energy, , is ∼0.3. The P(E(T))s indicate the production of fulvenallene + H, which was suggested by recent theoretical studies. The H-atom product angular distribution is isotropic, with the anisotropy parameter β ≈ 0. The H/D product ratios from isotope labeling studies using C(6)H(5)CD(2) and C(6)D(5)CH(2) are reasonably close to the statistical H/D ratios, suggesting that the H/D atoms are scrambled in the photodissociation of benzyl. The dissociation mechanism is consistent with internal conversion of the electronically excited benzyl followed by unimolecular decomposition of the hot benzyl radical on the ground state.

  2. Photodissociation of the OD radical at 226 and 243 nm

    International Nuclear Information System (INIS)

    Radenovic, Dragana C.; Roij, Andre J.A. van; Chestakov, Dmitri A.; Eppink, Andre T.J.B.; Meulen, J.J. ter; Parker, David H.; Loo, Mark P.J. van der; Groenenboom, Gerrit C.; Greenslade, Margaret E.; Lester, Marsha I.

    2003-01-01

    The photodissociation dynamics of state selected OD radicals has been examined at 243 and 226 nm using velocity map imaging to probe the angle-speed distributions of the D( 2 S) and O( 3 P 2 ) products. Both experiment and complementary first principle calculations demonstrate that photodissociation occurs by promotion of OD from high vibrational levels of the ground X 2 Π state to the repulsive 1 2 Σ - state

  3. Standing footprint diagnostic method

    Science.gov (United States)

    Fan, Y. F.; Fan, Y. B.; Li, Z. Y.; Newman, T.; Lv, C. S.; Fan, Y. Z.

    2013-10-01

    Center of pressure is commonly used to evaluate standing balance. Even though it is incomplete, no better evaluation method has been presented. We designed our experiment with three standing postures: standing with feet together, standing with feet shoulder width apart, and standing with feet slightly wider than shoulder width. Our platform-based pressure system collected the instantaneous plantar pressure (standing footprint). A physical quantity of instantaneous standing footprint principal axis was defined, and it was used to construct an index to evaluate standing balance. Comparison between results from our newly established index and those from the center of pressure index to evaluate the stability of different standing postures revealed that the standing footprint principal axis index could better respond to the standing posture change than the existing one. Analysis indicated that the insensitive response to the relative position between feet and to the standing posture change from the center of pressure could be better detected by the standing footprint principal axis index. This predicts a wide application of standing footprint principal axis index when evaluating standing balance.

  4. Fast beam studies of free radical photodissociation

    Energy Technology Data Exchange (ETDEWEB)

    Cyr, Douglas Robert [Univ. of California, Berkeley, CA (United States)

    1993-11-01

    The photodissociation of free radicals is studied in order to characterize the spectroscopy and dissociation dynamics of the dissociative electronic states in these species. To accomplish this, a novel method of radical production, based on the photodetachment of the corresponding negative ion, has been combined with a highly complementary form of photofragment translational spectroscopy. The optical spectroscopy of transitions to dissociative states is determined by monitoring the total photofragment yield as a function of dissociation photon energy. Branching ratios to various product channels, internal energy distributions of the fragments, bond dissociation energies, and the translational energy-dependent photofragment recoil angular distributions are then determined at selected excitation energies. A detailed picture of the dissociation dynamics can then be formulated, allowing insight concerning the interactions of potential energy surfaces involved in the dissociation. After an introduction to the concepts and techniques mentioned above, the experimental apparatus used in these experiments is described in detail. The basis and methods used in the treatment of data, especially in the dissociation dynamics experiments, are then put forward.

  5. Fast beam studies of free radical photodissociation

    International Nuclear Information System (INIS)

    Cyr, D.R.; California Univ., Berkeley, CA

    1993-11-01

    The photodissociation of free radicals is studied in order to characterize the spectroscopy and dissociation dynamics of the dissociative electronic states in these species. To accomplish this, a novel method of radical production, based on the photodetachment of the corresponding negative ion, has been combined with a highly complementary form of photofragment translational spectroscopy. The optical spectroscopy of transitions to dissociative states is determined by monitoring the total photofragment yield as a function of dissociation photon energy. Branching ratios to various product channels, internal energy distributions of the fragments, bond dissociation energies, and the translational energy-dependent photofragment recoil angular distributions are then determined at selected excitation energies. A detailed picture of the dissociation dynamics can then be formulated, allowing insight concerning the interactions of potential energy surfaces involved in the dissociation. After an introduction to the concepts and techniques mentioned above, the experimental apparatus used in these experiments is described in detail. The basis and methods used in the treatment of data, especially in the dissociation dynamics experiments, are then put forward

  6. Study of photodissociation parameters of carboxyhemoglobin

    International Nuclear Information System (INIS)

    Kuz'min, V V; Salmin, V V; Provorov, A S; Salmina, A B

    2008-01-01

    The general properties of photodissociation of carboxyhemoglobin (HbCO) in buffer solutions of whole human blood are studied by the flash photolysis method on a setup with intersecting beams. It is shown that the efficiency of photoinduced dissociation of the HbCO complex virtually linearly depends on the photolytic irradiation intensity for the average power density not exceeding 45 mW cm -2 . The general dissociation of the HbCO complex in native conditions occurs in a narrower range of values of the saturation degree than in model experiments with the hemoglobin solution. The dependence of the pulse photolysis efficiency of HbCO on the photolytic radiation wavelength in the range from 550 to 585 nm has a broad bell shape. The efficiency maximum corresponds to the electronic Q transition (porphyrin π-π* absorption) in HbCO at a wavelength of 570 nm. No dissociation of the complex was observed under given experimental conditions upon irradiation of solutions by photolytic radiation at wavelengths above 585 nm. (laser applications and other topics in quantum electronics)

  7. Skallerup Klit's carbon footprint

    DEFF Research Database (Denmark)

    Zacho, Kristina Overgaard; Ørnstrup, Niels Holm; Zimmermann, Tine Marquard

    by offsetting and without making actual emission reductions. Therefore the purpose of this study is to present recommendations on how Skallerup Klit can build up their business strategy using Carbon Footprint (CFP) as a tool. The CPF is calculated and assessed by using financial data in an Input-output LCA...

  8. Water footprints and 'pozas'

    NARCIS (Netherlands)

    Domínguez Guzmán, Carolina; Verzijl, Andres; Zwarteveen, Margreet

    2017-01-01

    In this article we present two logics of water efficiency: that of the Water Footprint and that of mango smallholder farmers on the desert coast of Peru (in Motupe). We do so in order to explore how both can learn from each other and to discuss what happens when the two logics meet. Rather than

  9. Photodissociation dynamics and spectroscopy of free radical combustion intermediates

    Energy Technology Data Exchange (ETDEWEB)

    Osborn, David Lewis [Univ. of California, Berkeley, CA (United States)

    1996-12-01

    The photodissociation spectroscopy and dynamics of free radicals is studied by the technique of fast beam photofragment translational spectroscopy. Photodetachment of internally cold, mass-selected negative ions produces a clean source of radicals, which are subsequently dissociated and detected. The photofragment yield as a function of photon energy is obtained, mapping out the dissociative and predissociative electronic states of the radical. In addition, the photodissociation dynamics, product branching ratios, and bond energies are probed at fixed photon energies by measuring the translational energy, P(ET), and angular distribution of the recoiling fragments using a time- and position-sensitive detector. Ab initio calculations are combined with dynamical and statistical models to interpret the observed data. The photodissociation of three prototypical hydrocarbon combustion intermediates forms the core of this work.

  10. The photodissociation and reaction dynamics of vibrationally excited molecules

    Energy Technology Data Exchange (ETDEWEB)

    Crim, F.F. [Univ. of Wisconsin, Madison (United States)

    1993-12-01

    This research determines the nature of highly vibrationally excited molecules, their unimolecular reactions, and their photodissociation dynamics. The goal is to characterize vibrationally excited molecules and to exploit that understanding to discover and control their chemical pathways. Most recently the author has used a combination of vibrational overtone excitation and laser induced fluorescence both to characterize vibrationally excited molecules and to study their photodissociation dynamics. The author has also begun laser induced grating spectroscopy experiments designed to obtain the electronic absorption spectra of highly vibrationally excited molecules.

  11. Rotorwash Operational Footprint Modeling

    Science.gov (United States)

    2014-07-01

    I-13. Francis, J. K., and Gillespie, A., “Relating Gust Speed to Tree Damage in Hurricane Hugo , 1989,” Journal of Arboriculture, November 1993...statement has been Rotorwash Operational Footprint Modeling 72 found to be correct. In many parts of the United States, the requirements for hurricane ...On August 18, 1983, Hurricane Alicia struck downtown Houston, Texas. Researchers were allowed into downtown Houston the following day to help survey

  12. Pyrite footprinting of RNA

    International Nuclear Information System (INIS)

    Schlatterer, Jörg C.; Wieder, Matthew S.; Jones, Christopher D.; Pollack, Lois; Brenowitz, Michael

    2012-01-01

    Highlights: ► RNA structure is mapped by pyrite mediated · OH footprinting. ► Repetitive experiments can be done in a powdered pyrite filled cartridge. ► High · OH reactivity of nucleotides imply dynamic role in Diels–Alderase catalysis. -- Abstract: In RNA, function follows form. Mapping the surface of RNA molecules with chemical and enzymatic probes has revealed invaluable information about structure and folding. Hydroxyl radicals ( · OH) map the surface of nucleic acids by cutting the backbone where it is accessible to solvent. Recent studies showed that a microfluidic chip containing pyrite (FeS 2 ) can produce sufficient · OH to footprint DNA. The 49-nt Diels–Alder RNA enzyme catalyzes the C–C bond formation between a diene and a dienophile. A crystal structure, molecular dynamics simulation and atomic mutagenesis studies suggest that nucleotides of an asymmetric bulge participate in the dynamic architecture of the ribozyme’s active center. Of note is that residue U42 directly interacts with the product in the crystallized RNA/product complex. Here, we use powdered pyrite held in a commercially available cartridge to footprint the Diels–Alderase ribozyme with single nucleotide resolution. Residues C39 to U42 are more reactive to · OH than predicted by the solvent accessibility calculated from the crystal structure suggesting that this loop is dynamic in solution. The loop’s flexibility may contribute to substrate recruitment and product release. Our implementation of pyrite-mediated · OH footprinting is a readily accessible approach to gleaning information about the architecture of small RNA molecules.

  13. Combining UV photodissociation with electron transfer for peptide structure analysis

    Czech Academy of Sciences Publication Activity Database

    Shaffer, C. J.; Marek, Aleš; Pepin, R.; Slováková, K.; Tureček, F.

    2015-01-01

    Roč. 50, č. 3 (2015), s. 470-475 ISSN 1076-5174 Institutional support: RVO:61388963 Keywords : electron transfer dissociation * laser photodissociation * peptide ions * cation radical * chromophores * isomer distinction Subject RIV: CE - Biochemistry Impact factor: 2.541, year: 2015

  14. Controlling the branching ratio of photodissociation using aligned molecules

    DEFF Research Database (Denmark)

    Larsen, J.J.; Wendt-Larsen, I.; Stapelfeldt, H.

    1999-01-01

    Using a sample of iodine molecules, aligned by a strong, linearly polarized laser pulse, we control the branching ratio of the I+I and I+I* photodissociation channels by a factor of 26. The control relies on selective photoexcitation of two potential curves that each correlate adiabatically...

  15. Supercollider: Footprint approved

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    With the 'footprint' - the precise location of the 87-kilometre US Superconducting Supercollider, SSC, and its ancillary buildings - now approved, teams of specialists commissioned by the State of Texas swing into action to procure the 17,000 acres (69 million square metres) of land covered by the project. With the SSC Laboratory in Ellis County and the US Department of Energy (DoE, the overseeing government agency) both hiring manpower for this project to collide 20 TeV (20,000 GeV) proton beams before the end of the century, the host State of Texas is providing a helping hand

  16. Footprints of alien technology

    Science.gov (United States)

    Davies, P. C. W.

    2012-04-01

    If alien civilizations do, or did, exist, their technology will impact their environment. Some consideration has been given to the detection of large-scale astro-engineering, such as Dyson spheres. However, a very advanced technology might leave more subtle footprints requiring sophisticated scientific methods to uncover. We must not overlook the possibility that alien technology has impacted our immediate astronomical environment, even Earth itself, but probably a very long time ago. This raises the question of what traces, if anything, might remain today. I shall consider the possibilities of biological, geological and physical traces, and suggest ways that we might search for them.

  17. Hydropower's Biogenic Carbon Footprint.

    Science.gov (United States)

    Scherer, Laura; Pfister, Stephan

    2016-01-01

    Global warming is accelerating and the world urgently needs a shift to clean and renewable energy. Hydropower is currently the largest renewable source of electricity, but its contribution to climate change mitigation is not yet fully understood. Hydroelectric reservoirs are a source of biogenic greenhouse gases and in individual cases can reach the same emission rates as thermal power plants. Little is known about the severity of their emissions at the global scale. Here we show that the carbon footprint of hydropower is far higher than previously assumed, with a global average of 173 kg CO2 and 2.95 kg CH4 emitted per MWh of electricity produced. This results in a combined average carbon footprint of 273 kg CO2e/MWh when using the global warming potential over a time horizon of 100 years (GWP100). Nonetheless, this is still below that of fossil energy sources without the use of carbon capture and sequestration technologies. We identified the dams most promising for capturing methane for use as alternative energy source. The spread among the ~1500 hydropower plants analysed in this study is large and highlights the importance of case-by-case examinations.

  18. Hydropower's Biogenic Carbon Footprint

    Science.gov (United States)

    Pfister, Stephan

    2016-01-01

    Global warming is accelerating and the world urgently needs a shift to clean and renewable energy. Hydropower is currently the largest renewable source of electricity, but its contribution to climate change mitigation is not yet fully understood. Hydroelectric reservoirs are a source of biogenic greenhouse gases and in individual cases can reach the same emission rates as thermal power plants. Little is known about the severity of their emissions at the global scale. Here we show that the carbon footprint of hydropower is far higher than previously assumed, with a global average of 173 kg CO2 and 2.95 kg CH4 emitted per MWh of electricity produced. This results in a combined average carbon footprint of 273 kg CO2e/MWh when using the global warming potential over a time horizon of 100 years (GWP100). Nonetheless, this is still below that of fossil energy sources without the use of carbon capture and sequestration technologies. We identified the dams most promising for capturing methane for use as alternative energy source. The spread among the ~1500 hydropower plants analysed in this study is large and highlights the importance of case-by-case examinations. PMID:27626943

  19. Carbon footprinting in supply chains

    NARCIS (Netherlands)

    Boukherroub, T.; Bouchery, Y.; Corbett, C.J.; Fransoo, J.C.; Tan, T.; Bouchery, Y.; Corbett, C.J.; Fransoo, J.C.; Tan, T.

    2017-01-01

    This chapter presents an overview of the methods and challenges behind carbon footprinting at the supply chain level. We start by providing some information about the scientific background on climate change. This information is necessary to clarify the overall methodology behind carbon footprinting

  20. Photodissociation of Small Molecules and Photoionization of Free Radicals Using the VUV Velocity-Map Imaging Photoion and Photoelectron Method

    Science.gov (United States)

    Gao, Hong

    (2012). (Chapter 2) 2. Hong Gao, Yu Song, Lei Yang, Xiaoyu Shi, Qing-Zhu Yin, C. Y. Ng and William M. Jackson. "Branching ratio measurements of the predissociation of 12C16O by time-slice velocity-map ion imaging in the energy region from 108,000 to 110,500 cm-1", the Journal of Chemical Physics, 137, 034305 (2012). (Chapter 3) 3. Hong Gao, Yu Song, Yih-Chung Chang, Xiaoyu Shi, Qing-Zhu Yin, Roger C. Wiens, William M. Jackson, C. Y. Ng, "Branching Ratio Measurements for Vacuum Ultraviolet Photodissociation of 12C16O", the Journal of Physical Chemistry A. (article online ASAP). (Chapter 4) 4. Hong Gao, Yu Song, C. Y. Ng, William M. Jackson, " Communication: State-to-state photodissociation study by the two-color VUV-VUV laser pump-probe time-slice velocity-map-imaging-photoion method", the Journal of Chemical Physics, 138, 191102(2013). (Chapter 5) 5. Hong Gao, Zhou Lu, Lei Yang, Jingang Zhou, C. Y. Ng, "Communication: A vibrational study of propargyl cation using the vacuum ultraviolet laser velocity-map imaging photoelectron method", the Journal of Chemical Physics, 137, 161101(2012). (Chapter 6)

  1. Photodissociation spectroscopy and dynamics of free radicals, clusters, and ions

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hyeon [Univ. of California, Berkeley, CA (United States)

    1999-12-01

    The photodissociation spectroscopy and dynamics of free radicals and ions is studied to characterize the dissociative electronic states in these species. To accomplish this, a special method of radical production, based on the photodetachment of the corresponding negative ion, has been combined with the technique of fast beam photofragment translational spectroscopy. The photofragment yield as a function of photon energy is obtained, mapping out the dissociative and predissociative electronic states. Branching ratios to various product channels, the translational energy distributions of the fragments, and bond dissociation energies are then determined at selected photon energies. The detailed picture of photodissociation dynamics is provided with the aid of ab initio calculations and a statistical model to interpret the observed data. Important reaction intermediates in combustion reactions have been studied: CCO, C2H5O, and linear Cn (n = 4--6).

  2. Green Chemistry Challenge: 2017 Small Business Award

    Science.gov (United States)

    Green Chemistry Challenge 2017 award winner, UniEnergy,improved a vanadium redox flow battery to double the energy density, have a broader operating temperature range, a smaller footprint, reduced chemical usage, and very little capacity degradation.

  3. Green Chemistry Metrics with Special Reference to Green Analytical Chemistry

    OpenAIRE

    Marek Tobiszewski; Mariusz Marć; Agnieszka Gałuszka; Jacek Namieśnik

    2015-01-01

    The concept of green chemistry is widely recognized in chemical laboratories. To properly measure an environmental impact of chemical processes, dedicated assessment tools are required. This paper summarizes the current state of knowledge in the field of development of green chemistry and green analytical chemistry metrics. The diverse methods used for evaluation of the greenness of organic synthesis, such as eco-footprint, E-Factor, EATOS, and Eco-Scale are described. Both the well-establis...

  4. A better carbon footprint label

    DEFF Research Database (Denmark)

    Thøgersen, John; Nielsen, Kristian S.

    2016-01-01

    , participants saw the original Carbon Trust label and in the other condition they saw the same label, but with traffic light colors added to communicate the product’s relative performance in terms of carbon footprint. All included attributes were found to have a significant impact on consumer choices....... As expected, price and carbon footprint were negatively related to choice. Further, participants preferred organic to non-organic coffee and certification by a public authority. The effect of the carbon label is significantly stronger the more environmentally concerned the consumer is. Using colors...... to indicate relative carbon footprint significantly increases carbon label effectiveness. Hence, a carbon footprint label is more effective if it uses traffic light colors to communicate the product’s relative performance....

  5. FLORIDA TOWER FOOTPRINT EXPERIMENTS

    Energy Technology Data Exchange (ETDEWEB)

    WATSON,T.B.; DIETZ, R.N.; WILKE, R.; HENDREY, G.; LEWIN, K.; NAGY, J.; LECLERC, M.

    2007-01-01

    The Florida Footprint experiments were a series of field programs in which perfluorocarbon tracers were released in different configurations centered on a flux tower to generate a data set that can be used to test transport and dispersion models. These models are used to determine the sources of the CO{sub 2} that cause the fluxes measured at eddy covariance towers. Experiments were conducted in a managed slash pine forest, 10 km northeast of Gainesville, Florida, in 2002, 2004, and 2006 and in atmospheric conditions that ranged from well mixed, to very stable, including the transition period between convective conditions at midday to stable conditions after sun set. There were a total of 15 experiments. The characteristics of the PFTs, details of sampling and analysis methods, quality control measures, and analytical statistics including confidence limits are presented. Details of the field programs including tracer release rates, tracer source configurations, and configuration of the samplers are discussed. The result of this experiment is a high quality, well documented tracer and meteorological data set that can be used to improve and validate canopy dispersion models.

  6. City Carbon Footprint Networks

    Directory of Open Access Journals (Sweden)

    Guangwu Chen

    2016-07-01

    Full Text Available Progressive cities worldwide have demonstrated political leadership by initiating meaningful strategies and actions to tackle climate change. However, the lack of knowledge concerning embodied greenhouse gas (GHG emissions of cities has hampered effective mitigation. We analyse trans-boundary GHG emission transfers between five Australian cities and their trading partners, with embodied emission flows broken down into major economic sectors. We examine intercity carbon footprint (CF networks and disclose a hierarchy of responsibility for emissions between cities and regions. Allocations of emissions to households, businesses and government and the carbon efficiency of expenditure have been analysed to inform mitigation policies. Our findings indicate that final demand in the five largest cities in Australia accounts for more than half of the nation’s CF. City households are responsible for about two thirds of the cities’ CFs; the rest can be attributed to government and business consumption and investment. The city network flows highlight that over half of emissions embodied in imports (EEI to the five cities occur overseas. However, a hierarchy of GHG emissions reveals that overseas regions also outsource emissions to Australian cities such as Perth. We finally discuss the implications of our findings on carbon neutrality, low-carbon city concepts and strategies and allocation of subnational GHG responsibility.

  7. Single photon excimer laser photodissociation of highly vibrationally excited polyatomic molecules

    International Nuclear Information System (INIS)

    Tiee, J.J.; Wampler, F.B.; Rice, W.W.

    1980-01-01

    The ir + uv photodissociation of SF 6 has been performed using CO 2 and ArF lasers. The two-color photolysis significantly enhances the photodissociation process over ArF irradiation alone and is found to preserve the initial isotopic specificity of the ir excitation process

  8. Intracluster superelastic scattering via sequential photodissociation in small HI clusters

    International Nuclear Information System (INIS)

    Chastaing, D.; Underwood, J.; Wittig, C.

    2003-01-01

    The photodissociation of expansion-cooled HI monomer by using 266 nm radiation yields H atoms having 12 830 and 5287 cm-1 of translational energy in the HI center-of-mass system for the I( 2 P 3/2 ) and I( 2 P 1/2 ) (i.e., I and I * , respectively) co-fragments. Irradiating HI clusters [i.e., (HI) n , with n=2 being the dominant cluster] with 266 nm radiation produces, among other things, some H atoms whose translational energies are peaked at 20 285 cm-1, which is 7455 cm-1 higher in energy than the more energetic of the monomer peaks. These very fast H atoms arise from sequential photodissociation within the clusters. Namely, a weakly bound I*·(HI) n-1 complex is first created by the photodissociation of an HI moiety within (HI) n , and then the photodissociation of a second HI moiety [within I*·(HI) n-1 ] produces a fast H atom that scatters from the nearby I*, in some cases deactivating it in the process. Thus, the latter superelastically scattered H atom acquires, as translational energy, nearly all of the I* energy (7603 cm-1). For example, for the dimer, the first dissociation event, (HI) 2 +hv→H+I(I*)·HI, is followed by I*·HI+hv→H superelastic +I-I. High quality potentials for the relevant HI excited states have been calculated recently, and coupling between 3 Π 0 + (which correlates with I * ) and 1 Π (which correlates with I) has been shown to be due to spin-rotation interaction. There is a high degree of separability between the photodissociation of the second HI moiety and the subsequent H+I * scattering (within a given cluster). This is due mainly to the shape of the 3 Π 0 + potential; specifically, it has a shallow well that persists to small r. The shape of the 3 Π 0 + potential is influenced by relativity; i.e., strong spin-orbit coupling maintains the I* spherical electron density to relatively small r. The 3 Π 0 + → 1 Π transition probabilities are calculated for H+I * collisions having different values of the collisional orbital

  9. Progress and Prospects for Tourism Footprint Research

    Directory of Open Access Journals (Sweden)

    Shuxin Wang

    2017-10-01

    Full Text Available The tourism footprint family comprises the tourism ecological footprint (TEF, the tourism carbon footprint (TCF and the tourism water footprint (TWF. The tourism footprint represents an important tool for quantitatively assessing the impact of tourism activities on the ecosystem of a tourist destination. This paper systematically reviews the relevant literature on TEF, TCF and TWF, analyses and summarizes the main progress and failures in the analytical frameworks, research methods, measurement results, environmental impacts and reductions in the tourism footprint. This paper also proposes areas for further developing the tourism footprint research, including unifying the analytical frameworks and boundaries of the tourism footprint, distinguishing the geographical scope of the tourism footprint effectively, improving the process of analyzing the environmental impact of the tourism footprint, measuring the tourism footprint scientifically and roundly, performing space-time calculations of the tourism footprint, and expanding the tourism footprint family by introducing new members. Accordingly, this paper is devoted to the continued study of the tourism footprint.

  10. Laser photodissociation and spectroscopy of mass-separated biomolecular ions

    CERN Document Server

    Polfer, Nicolas C

    2014-01-01

    This lecture notes book presents how enhanced structural information of biomolecular ions can be obtained from interaction with photons of specific frequency - laser light. The methods described in the book ""Laser photodissociation and spectroscopy of mass-separated biomolecular ions"" make use of the fact that the discrete energy and fast time scale of photoexcitation can provide more control in ion activation. This activation is the crucial process producing structure-informative product ions that cannot be generated with more conventional heating methods, such as collisional activation. Th

  11. Photodissociation and photoionisation of atoms and molecules of astrophysical interest

    Science.gov (United States)

    Heays, A. N.; Bosman, A. D.; van Dishoeck, E. F.

    2017-06-01

    A new collection of photodissociation and photoionisation cross sections for 102 atoms and molecules of astrochemical interest has been assembled, along with a brief review of the basic physical processes involved. These have been used to calculate dissociation and ionisation rates, with uncertainties, in a standard ultraviolet interstellar radiation field (ISRF) and for other wavelength-dependent radiation fields, including cool stellar and solar radiation, Lyman-α dominated radiation, and a cosmic-ray induced ultraviolet flux. The new ISRF rates generally agree within 30% with our previous compilations, with a few notable exceptions. Comparison with other databases such as PHIDRATES is made. The reduction of rates in shielded regions was calculated as a function of dust, molecular and atomic hydrogen, atomic C, and self-shielding column densities. The relative importance of these shielding types depends on the atom or molecule in question and the assumed dust optical properties. All of the new data are publicly available from the Leiden photodissociation and ionisation database. Sensitivity of the calculated rates to variation of temperature and isotope, and uncertainties in measured or calculated cross sections, are tested and discussed. Tests were conducted on the new rates with an interstellar-cloud chemical model, and find general agreement (within a factor of two) in abundances obtained with the previous iteration of the Leiden database assuming an ISRF, and order-of-magnitude variations assuming various kinds of stellar radiation. The newly parameterised dust-shielding factors makes a factor-of-two difference to many atomic and molecular abundances relative to parameters currently in the UDfA and KIDA astrochemical reaction databases. The newly-calculated cosmic-ray induced photodissociation and ionisation rates differ from current standard values up to a factor of 5. Under high temperature and cosmic-ray-flux conditions the new rates alter the equilibrium

  12. Vacuum ultraviolet photoionization and photodissociation of polyatomic molecules and radicals

    Energy Technology Data Exchange (ETDEWEB)

    Ng, C.Y. [Iowa State Univ., Ames (United States)

    1993-12-01

    In the past decade, tremendous progress has been made in understanding the photodissociation (PD) dynamics of triatomic molecules. However, the PD study of radicals, especially polyatomic radicals, has remained essentially an unexplored research area. Detailed state-to-state PD cross sections for radicals in the UV and VUV provide challenges not only for dynamical calculations, but also for ab initio quantum chemical studies. The authors have developed a laser based pump-probe apparatus for the measurement of absolute PD cross sections for CH{sub 3}S and HS is summarized.

  13. Development of My Footprint Calculator

    Science.gov (United States)

    Mummidisetti, Karthik

    The Environmental footprint is a very powerful tool that helps an individual to understand how their everyday activities are impacting environmental surroundings. Data shows that global climate change, which is a growing concern for nations all over the world, is already affecting humankind, plants and animals through raising ocean levels, droughts & desertification and changing weather patterns. In addition to a wide range of policy measures implemented by national and state governments, it is necessary for individuals to understand the impact that their lifestyle may have on their personal environmental footprint, and thus over the global climate change. "My Footprint Calculator" (myfootprintcalculator.com) has been designed to be one the simplest, yet comprehensive, web tools to help individuals calculate and understand their personal environmental impact. "My Footprint Calculator" is a website that queries users about their everyday habits and activities and calculates their personal impact on the environment. This website was re-designed to help users determine their environmental impact in various aspects of their lives ranging from transportation and recycling habits to water and energy usage with the addition of new features that will allow users to share their experiences and their best practices with other users interested in reducing their personal Environmental footprint. The collected data is stored in the database and a future goal of this work plans to analyze the collected data from all users (anonymously) for developing relevant trends and statistics.

  14. Simulations of seismic acquisition footprint

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, J.; Margrave, G.; Lawton, D. [Calgary Univ., AB (Canada)

    2008-07-01

    Numerical simulations were performed to investigate the causes of commonly observed artefacts in seismic field data. These seismic acquisition footprints typically consist of modulations in recorded amplitudes that are spatially correlated to the surface locations of sources and receivers used in a survey. Two broad classes of footprint were considered, notably amplitude variations related to the edges of the survey and the amplitude variations in the interior of the survey. The variations in amplitude obscure the true reflection response of the subsurface. The MATLAB numerical modelling code was used to produce the synthetic seismic data and create a thorough dataset using a survey design incorporating dense grids of sources and receivers. The footprint consisting of periodic amplitude variations in the interior of the surveys, similar to that observed in field data and likely produced by poor sampling, was observed in the decimated dataset. This type of footprint varied in strength between images produced with different processing algorithms. The observed footprint in these simulations was most organized in the unmigrated stack and was somewhat randomized after poststack. 2 refs., 1 tab., 3 figs.

  15. Photodissociation spectroscopy of the dysprosium monochloride molecular ion

    Energy Technology Data Exchange (ETDEWEB)

    Dunning, Alexander, E-mail: alexander.dunning@gmail.com; Schowalter, Steven J.; Puri, Prateek; Hudson, Eric R. [Department of Physics and Astronomy, University of California, Los Angeles, California 90095 (United States); Petrov, Alexander; Kotochigova, Svetlana [Department of Physics, Temple University, Philadelphia, Pennsylvania 19122 (United States)

    2015-09-28

    We have performed a combined experimental and theoretical study of the photodissociation cross section of the molecular ion DyCl{sup +}. The photodissociation cross section for the photon energy range 35 500 cm{sup −1} to 47 500 cm{sup −1} is measured using an integrated ion trap and time-of-flight mass spectrometer; we observe a broad, asymmetric profile that is peaked near 43 000 cm{sup −1}. The theoretical cross section is determined from electronic potentials and transition dipole moments calculated using the relativistic configuration-interaction valence-bond and coupled-cluster methods. The electronic structure of DyCl{sup +} is extremely complex due to the presence of multiple open electronic shells, including the 4f{sup 10} configuration. The molecule has nine attractive potentials with ionically bonded electrons and 99 repulsive potentials dissociating to a ground state Dy{sup +} ion and Cl atom. We explain the lack of symmetry in the cross section as due to multiple contributions from one-electron-dominated transitions between the vibrational ground state and several resolved repulsive excited states.

  16. Photodissociation and photoisomerization dynamics of CH2=CHCHO in solution

    International Nuclear Information System (INIS)

    Wu Weiqiang; Yang Chunfan; Zhao Hongmei; Liu Kunhui; Su Hongmei

    2010-01-01

    By means of time-resolved Fourier transform infrared absorption spectroscopy, we have investigated the 193 nm photodissociation and photoisomerization dynamics of the prototype molecule of α,β-enones, acrolein (CH 2 =CHCHO) in CH 3 CN solution. The primary photolysis channels and absolute branching ratios are determined. The most probable reaction mechanisms are clarified by control experiments monitoring the product yields varied with the triplet quencher addition. The predominant channel is the 1,3-H migration yielding the rearrangement product CH 3 CH=C=O with a branching ratio of 0.78 and the less important channel is the α cleavage of C-H bond yielding radical fragments CH 2 =CHCO+H with a branching ratio of only 0.12. The 1,3-H migration is strongly suggested to correlate with the triplet 3 (ππ * ) state rather than the ground S 0 state and the α cleavage of C-H bond is more likely to proceed in the singlet S 1 1 (nπ * ) state. From the solution experiments we have not only acquired clues clarifying the previous controversial mechanisms, but also explored different photochemistry in solution. Compared to the gas phase photolysis which is dominated by photodissociation channels, the most important channel in solution is the photoisomerization of 1,3-H migration. The reason leading to the different photochemistry in solution is further ascribed to the solvent cage effect.

  17. Photodissociation and photoisomerization dynamics of CH2=CHCHO in solution

    Science.gov (United States)

    Wu, Weiqiang; Yang, Chunfan; Zhao, Hongmei; Liu, Kunhui; Su, Hongmei

    2010-03-01

    By means of time-resolved Fourier transform infrared absorption spectroscopy, we have investigated the 193 nm photodissociation and photoisomerization dynamics of the prototype molecule of α,β-enones, acrolein (CH2CHCHO) in CH3CN solution. The primary photolysis channels and absolute branching ratios are determined. The most probable reaction mechanisms are clarified by control experiments monitoring the product yields varied with the triplet quencher addition. The predominant channel is the 1,3-H migration yielding the rearrangement product CH3CHCO with a branching ratio of 0.78 and the less important channel is the α cleavage of CH bond yielding radical fragments CH2CHCO+H with a branching ratio of only 0.12. The 1,3-H migration is strongly suggested to correlate with the triplet (ππ ∗)3 state rather than the ground S0 state and the α cleavage of CH bond is more likely to proceed in the singlet S1 (nπ∗)1 state. From the solution experiments we have not only acquired clues clarifying the previous controversial mechanisms, but also explored different photochemistry in solution. Compared to the gas phase photolysis which is dominated by photodissociation channels, the most important channel in solution is the photoisomerization of 1,3-H migration. The reason leading to the different photochemistry in solution is further ascribed to the solvent cage effect.

  18. Quantum treatment of the Ar-HI photodissociation dynamics

    International Nuclear Information System (INIS)

    Lopez-Lopez, Sergio; Prosmiti, Rita; Garcia-Vela, Alberto

    2004-01-01

    A wave packet simulation of the ultraviolet photolysis dynamics of Ar-HI(v=0) is reported. Cluster photodissociation is started from two different initial states, namely, the ground van der Waals (vdW) and the first excited vdW bending state, associated with the Ar-I-H and Ar-H-I isomeric forms of the system, respectively. Formation of Ar-I radical products is investigated over the energy range of the cluster absorption spectrum. It is found that the yield of bound Ar-I radical complexes is typically 90%-100% and 70%-80% for the initial states associated with the Ar-I-H and Ar-H-I isomers, respectively. This result is in agreement with the experimentally observed time-of-flight spectrum of the hydrogen fragment produced after Ar-HI photodissociation. The high Ar-I yield is explained mainly by the small amount of energy available for the radical that is converted into internal energy in the photofragmentation process, which enhances the Ar-I survival probability. Quantum interference effects manifest themselves in structures in the angular distribution of the hydrogen fragment, and in pronounced rainbow patterns in the rotational distributions of the Ar-I radical

  19. Photodissociation spectroscopy of the Mg+-acetic acid complex

    Science.gov (United States)

    Abate, Yohannes; Kleiber, P. D.

    2006-11-01

    We have studied the structure and photodissociation of Mg+-acetic acid clusters. Ab initio calculations suggest four relatively strongly bound ground state isomers for the [MgC2H4O2]+ complex. These isomers include the cis and trans forms of the Mg+-acetic acid association complex with Mg+ bonded to the carbonyl O atom of acetic acid, the Mg+-acetic acid association complex with Mg+ bonded to the hydroxyl O atom of acetic acid, or to a Mg+-ethenediol association complex. Photodissociation through the Mg+-based 3p←3s absorption bands in the near UV leads to direct (nonreactive) and reactive dissociation products: Mg+, MgOH+, Mg(H2O )+, CH3CO+, and MgCH3+. At low energies the dominant reactive quenching pathway is through dehydration to Mg(H2O)+, but additional reaction channels involving C-H and C-C bond activation are also open at higher energies.

  20. Mathematical Footprints Discovering Mathematics Everywhere

    CERN Document Server

    Pappas, Theoni

    1999-01-01

    MATHEMATICAL FOOTPRINTS takes a creative look at the role mathematics has played since prehistoric times, and will play in the future, and uncovers mathematics where you least expect to find it from its many uses in medicine, the sciences, and its appearance in art to its patterns in nature and its central role in the development of computers. Pappas presents mathematical ideas in a readable non-threatening manner. MATHEMATICAL FOOTPRINTS is another gem by the creator of THE MATHEMATICS CALENDAR and author of THE JOY OF MATHEMATICS. "Pappas's books have been gold mines of mathematical ent

  1. Chemistry in T Tauri winds

    Energy Technology Data Exchange (ETDEWEB)

    Rawlings, J M.C.; Williams, D A; Canto, J

    1988-02-15

    The chemistry occurring in the winds of T Tauri stars is investigated. On the assumption that the wind is dust-free, then routes to H/sub 2/ are inhibited under the conditions in the wind, and subsequent chemistry does not produce substantial molecular abundances. The major losses to the chemical network lie in the geometrical dilution and collisional dissociation rather than in chemical destruction and photodissociation. Mass loading of the wind with dust and H/sub 2/ may, however, occur. This stimulates the chemistry and may in some circumstances lead to a conversion of approx.1-10 per cent of carbon into CO. This gives a column density of CO which is marginally detectable. A positive detection of CO at high wind velocities would imply that the winds must be cool and that mixing of molecular material from a disc, which may play a role in collimating the wind, or the remnants of a disc, must occur.

  2. AgSat Imagery Collection Footprints

    Data.gov (United States)

    Farm Service Agency, Department of Agriculture — The AgSat Imagery Collection Footprints map shows the imagery footprints which have been collected under the USDA satellite blanket purchase agreement. Click on a...

  3. Metal footprint linked to economy

    Science.gov (United States)

    Burke, Paul J.

    2018-04-01

    The annual quantity of metal being used by humans has been on the rise. A new analysis of 43 major economies reveals the extent to which year-to-year fluctuations in metal footprints have been in lockstep with countries' economic growth and changes in investment spending.

  4. What Is My Carbon Footprint?

    Science.gov (United States)

    Galluzzo, Benjamin J.; McGivney-Burelle, Jean; Wagstrom, Rikki B.

    2016-01-01

    Human beings are having a profound impact on the environment. The opportunity to investigate this timely issue during one or two class periods gives algebra and precalculus students insight into a sustainability topic of great international concern--carbon footprints. Students use mathematical thinking in matters that are pertinent to their…

  5. Photoisomerization and photodissociation dynamics of reactive free radicals

    Energy Technology Data Exchange (ETDEWEB)

    Bise, Ryan T. [Univ. of California, Berkeley, CA (United States)

    2000-08-01

    The photofragmentation pathways of chemically reactive free radicals have been examined using the technique of fast beam photofragment translational spectroscopy. Measurements of the photodissociation cross-sections, product branching ratios, product state energy distributions, and angular distributions provide insight into the excited state potential energy surfaces and nonadiabatic processes involved in the dissociation mechanisms. Photodissociation spectroscopy and dynamics of the predissociative $\\tilde{A}$2A1 and $\\tilde{B}$2A2 states of CH3S have been investigated. At all photon energies, CH3 + S(3Pj), was the main reaction channel. The translational energy distributions reveal resolved structure corresponding to vibrational excitation of the CH3 umbrella mode and the S(3Pj) fine-structure distribution from which the nature of the coupled repulsive surfaces is inferred. Dissociation rates are deduced from the photofragment angular distributions, which depend intimately on the degree of vibrational excitation in the C-S stretch. Nitrogen combustion radicals, NCN, CNN and HNCN have also been studied. For all three radicals, the elimination of molecular nitrogen is the primary reaction channel. Excitation to linear excited triplet and singlet electronic states of the NCN radical generates resolved vibrational structure of the N2 photofragment. The relatively low fragment rotational excitation suggests dissociation via a symmetric C2V transition state. Resolved vibrational structure of the N2 photofragment is also observed in the photodissociation of the HNCN radical. The fragment vibrational and rotational distributions broaden with increased excitation energy. Simple dissociation models suggest that the HNCN radical isomerizes to a cyclic intermediate (c-HCNN) which then dissociates via a tight cyclic

  6. Multiphonon generation during photodissociation of slow Landau-Pekar polarons

    International Nuclear Information System (INIS)

    Myasnikov, E. N.; Myasnikova, A. E.; Mastropas, Z. P.

    2006-01-01

    The spectra of the low-temperature photodissociation (photoionization) of Landau-Pekar polarons are calculated using the theory of quantum-coherent states and a new method of variation with respect to the parameters of phonon vacuum deformation. It is shown that the final polaron states upon photodissociation may have different numbers of phonons produced in a single dissociation event and different momenta of charge carriers. The spectrum of optical absorption related to the photodissociation of polarons exhibits a superposition of bands corresponding to various numbers of phonons formed as a result of dissociation of a single polaron. Due to a large width of the energy region corresponding to the final states of charge carriers, the halfwidth of each band is on the order of the energy of polaron coupling and is much greater than the phonon energy. For this reason, the individual phonon bands exhibit strong overlap. The very broad and, probably, structureless band formed as a result of the superposition of all these components begins at an energy equal to the sum of the polaron coupling energy (E p ) and the phonon energy. This band has a maximum at a frequency of about 5.6E p /ℎ and a halfwidth on the order of 5.6E p /ℎ at a unit effective mass (m* = m e ) of band electrons. For an effective charge carrier mass within m* = (1-3)m e , the energy of the polaron band maximum can be estimated as 5E p with an error of about 10%, and the halfwidth falls within 3.4E p 1/2 p . The multiphonon character of this band is related to a decay of the phonon condensate after the escape of charge carrier from a polaron. Such polarons are likely to be observed in the spectra of complex metal oxides, including high-temperature superconductors. Examples of such polaron bands in the reported absorption and photoconductivity spectra of nonstoichiometric cuprates, manganites, nickelates, and titanates are presented. A theory of the formation of Landau-Pekar polarons with the

  7. The photodissociation of 8B and the solar neutrino problem

    International Nuclear Information System (INIS)

    Bertulani, C.A.

    1995-01-01

    The extraction of the photodissociation cross sections of 8 B from Coulomb dissociation experiments is investigated. A careful study is done on the contributions of the E1, E2 and M1 multipolarities to the breakup. A comparison with the data of a recent experiment is performed. It is shown that the extraction of the radiative capture cross sections 7 Be(p, γ) 8 B which are relevant for the solar neutrino problem is not affected appreciably by Coulomb reacceleration. A non-perturbative model is used for the purpose. Emphasis is put on the perspectives for future experiments which are planned at the University of Notre Dame, RIKEN (Japan), and GSI (Germany). An analysis of the total yields of ''photon-point'' processes in inelastic electron scattering is also done. (orig.)

  8. UV photodissociation spectroscopy of oxidized undecylenic acid films.

    Science.gov (United States)

    Gomez, Anthony L; Park, Jiho; Walser, Maggie L; Lin, Ao; Nizkorodov, Sergey A

    2006-03-16

    Oxidation of thin multilayered films of undecylenic (10-undecenoic) acid by gaseous ozone was investigated using a combination of spectroscopic and mass spectrometric techniques. The UV absorption spectrum of the oxidized undecylenic acid film is significantly red-shifted compared to that of the initial film. Photolysis of the oxidized film in the tropospheric actinic region (lambda > 295 nm) readily produces formaldehyde and formic acid as gas-phase products. Photodissociation action spectra of the oxidized film suggest that organic peroxides are responsible for the observed photochemical activity. The presence of peroxides is confirmed by mass-spectrometric analysis of the oxidized sample and an iodometric test. Significant polymerization resulting from secondary reactions of Criegee radicals during ozonolysis of the film is observed. The data strongly imply the importance of photochemistry in aging of atmospheric organic aerosol particles.

  9. Photodissociation of HBr/LiF(001) - A quantum mechanical model

    Science.gov (United States)

    Seideman, Tamar

    1993-01-01

    The photodissociation dynamics of HBr adsorbed on an LiF(001) surface is studied using time-independent quantum mechanics. The photodissociation line shape and the Br(2P(1/2))/Br(2P(3/2)) yield ratio are computed and compared with the corresponding quantities for gas phase photodissociation. The angular distribution of the hydrogen photofragments following excitation of adsorbed HBr is computed and found to agree qualitatively with experimental data. The effect of polarization of the photon is illustrated and discussed. We find the field polarization to affect significantly the magnitude of the photodissociation signal but not the angular dependence of the photofragment distribution, in agreement with experiment and in accord with expectations for a strongly aligned adsorbed phase.

  10. Photodissociation of HBr/LiF(001): A quantum mechanical model

    Science.gov (United States)

    Seideman, Tamar

    1993-01-01

    The photodissociation dynamics of HBr adsorbed on a LiF(001) surface is studied using time-independent quantum mechanics. The photodissociation lineshape and the Br(P(sub 1/2)-2)/Br(P(sub 3/2)-2) yield ratio are computed and compared with the corresponding quantities for gas phase photodissociation. The angular distribution of the hydrogen photofragments following excitation of adsorbed HBr is computed and found to agree qualitatively with experimental data. The effect of polarization of the photon is illustrated and discussed. The field polarization is found to affect significantly the magnitude of the photodissociation signal but not the angular dependence of the photofragment distribution, in agreement with experiment and in accord with expectations for a strongly aligned adsorbed phase.

  11. Presidential Green Chemistry Challenge: 2013 Designing Greener Chemicals Award

    Science.gov (United States)

    Presidential Green Chemistry Challenge 2013 award winner, Cargill, Inc., developed a vegetable-oil-based transformer fluid that is much less flammable, provides superior performance, is less toxic, and has a substantially lower carbon footprint.

  12. Carbon footprinting of electronic products

    International Nuclear Information System (INIS)

    Vasan, Arvind; Sood, Bhanu; Pecht, Michael

    2014-01-01

    Highlights: • Challenges in adopting existing CF standards for electronic products are discussed. • Carbon footprint of electronic products is underestimated using existing standards. • Multipronged approach is presented to overcome the identified challenges. • Multipronged approach demonstrated on commercial and military grade DC–DC converter system. - Abstract: In order to mitigate the effects of global warming, companies are being compelled by governments, investors, and customers to control their greenhouse gas (GHG) emissions. Similar to the European Union’s legislation on the airline industry, legislation is expected to require the electronics industry to assess their product’s carbon footprint before sale or use, as the electronics industry’s contribution to global GHG emissions is comparable to the airline industry’s contribution. Thus, it is necessary for members of the electronics industry to assess their current GHG emission rates and identify methods to reduce environmental impacts. Organizations use Carbon Footprint (CF) analysis methods to identify and quantify the GHG emissions associated with the life cycle stages of their product or services. This paper discusses the prevailing methods used by organizations to estimate the CF of their electronics products and identifies the challenges faced by the electronics industry when adopting these methods in an environment of decreasing product development cycles with complex and diffuse supply chains. We find that, as a result of the inconsistencies arising from the system boundary selection methods and databases, the use of outdated LCA approaches, and the lack of supplier’s emissions-related data, the CFs of electronic products are typically underestimated. To address these challenges, we present a comprehensive approach to the carbon footprinting of electronic products that involves the use of product-group-oriented standards, hybrid life cycle assessment techniques, and the

  13. Phylogenetic footprints in organizational behavior

    OpenAIRE

    Witt, Ulrich; Schwesinger, Georg

    2012-01-01

    An evolutionary tool kit is applied in this paper to explain how innate social behavior traits evolved in early human groups. These traits were adapted to the particular production requirements of the group in human phylogeny. They shaped the group members' attitudes towards contributing to the group's goals and towards other group members. We argue that these attitudes are still present in modern humans and leave their phylogenetic footprints also in present-day organizational life. We discu...

  14. Geometric morphometric footprint analysis of young women

    OpenAIRE

    Domjanic, Jacqueline; Fieder, Martin; Seidler, Horst; Mitteroecker, Philipp

    2013-01-01

    Background Most published attempts to quantify footprint shape are based on a small number of measurements. We applied geometric morphometric methods to study shape variation of the complete footprint outline in a sample of 83 adult women. Methods The outline of the footprint, including the toes, was represented by a comprehensive set of 85 landmarks and semilandmarks. Shape coordinates were computed by Generalized Procrustes Analysis. Results The first four principal components represented t...

  15. Theoretical study of ultraviolet induced photodissociation dynamics of sulfuric acid

    Energy Technology Data Exchange (ETDEWEB)

    Murakami, Tatsuhiro; Ohta, Ayumi; Suzuki, Tomoya; Ikeda, Kumiko [Department of Materials and Life Sciences, Faculty of Science and Technology, Sophia University, 7-1 Kioi-Cho, Chiyoda-ku, Tokyo 102-8554 (Japan); Danielache, Sebastian O. [Department of Materials and Life Sciences, Faculty of Science and Technology, Sophia University, 7-1 Kioi-Cho, Chiyoda-ku, Tokyo 102-8554 (Japan); Earth-Life Science Institute (ELSI), Tokyo Institute of Technology (Japan); Department of Environmental Science and Techonology, Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, Yoohama 226-8502 (Japan); Nanbu, Shinkoh, E-mail: shinkoh.nanbu@sophia.ac.jp [Department of Materials and Life Sciences, Faculty of Science and Technology, Sophia University, 7-1 Kioi-Cho, Chiyoda-ku, Tokyo 102-8554 (Japan)

    2015-05-01

    Highlights: • Photodissociation dynamics of H{sub 2}SO{sub 4} at low-lying electronically excited states were investigated. • Photochemical processes were simulated by on-the-fly ab initio MD. • Sulfuric acid after the excitation to the S{sub 1} state dissociated to HSO{sub 4}(1{sup 2}A″) + H({sup 2}S). • Sulfuric acid after the excitation to the S{sub 2} state dissociated to HSO{sub 4}(2{sup 2}A″) + H({sup 2}S). • The energy region of the UV spectra where NMD fractionation may occur is predicted. - Abstract: Photodissociation dynamics of sulfuric acid after excitation to the first and second excited states (S{sub 1} and S{sub 2}) were studied by an on-the-fly ab initio molecular dynamics simulations based on the Zhu–Nakamura version of the trajectory surface hopping (ZN-TSH). Forces acting on the nuclear motion were computed on-the-fly by CASSCF method with Dunning’s augmented cc-pVDZ basis set. It was newly found that the parent molecule dissociated into two reaction-channels (i) HSO{sub 4}(1{sup 2}A″) + H({sup 2}S) by S{sub 1}-excitation, and (ii) HSO{sub 4}(2{sup 2}A″) + H({sup 2}S) by S{sub 2}-excitation. The direct dissociation dynamics yield products different from the SO{sub 2} + 2OH fragments often presented in the literature. Both channels result in the same product and differs only in the electronic state of the HSO{sub 4} fragment{sub .} The trajectories running on S{sub 2} do not hop with S{sub 0} and a nonadiabatic transition happens at the S{sub 2}–S{sub 1} conical intersection located at a longer OH bond-length than the S{sub 1}–S{sub 0} intersection producing an electronic excited state (2{sup 2}A″) of HSO{sub 4} product.

  16. High precision optical spectroscopy and quantum state selected photodissociation of ultracold 88Sr2 molecules in an optical lattice

    Science.gov (United States)

    McDonald, Mickey

    2017-04-01

    Over the past several decades, rapid progress has been made toward the accurate characterization and control of atoms, epitomized by the ever-increasing accuracy and precision of optical atomic lattice clocks. Extending this progress to molecules will have exciting implications for chemistry, condensed matter physics, and precision tests of physics beyond the Standard Model. My thesis describes work performed over the past six years to establish the state of the art in manipulation and quantum control of ultracold molecules. We describe a thorough set of measurements characterizing the rovibrational structure of weakly bound 88Sr2 molecules from several different perspectives, including determinations of binding energies; linear, quadratic, and higher order Zeeman shifts; transition strengths between bound states; and lifetimes of narrow subradiant states. Finally, we discuss measurements of photofragment angular distributions produced by photodissociation of molecules in single quantum states, leading to an exploration of quantum-state-resolved ultracold chemistry. The images of exploding photofragments produced in these studies exhibit dramatic interference effects and strongly violate semiclassical predictions, instead requiring a fully quantum mechanical description.

  17. Carbon footprint: current methods of estimation.

    Science.gov (United States)

    Pandey, Divya; Agrawal, Madhoolika; Pandey, Jai Shanker

    2011-07-01

    Increasing greenhouse gaseous concentration in the atmosphere is perturbing the environment to cause grievous global warming and associated consequences. Following the rule that only measurable is manageable, mensuration of greenhouse gas intensiveness of different products, bodies, and processes is going on worldwide, expressed as their carbon footprints. The methodologies for carbon footprint calculations are still evolving and it is emerging as an important tool for greenhouse gas management. The concept of carbon footprinting has permeated and is being commercialized in all the areas of life and economy, but there is little coherence in definitions and calculations of carbon footprints among the studies. There are disagreements in the selection of gases, and the order of emissions to be covered in footprint calculations. Standards of greenhouse gas accounting are the common resources used in footprint calculations, although there is no mandatory provision of footprint verification. Carbon footprinting is intended to be a tool to guide the relevant emission cuts and verifications, its standardization at international level are therefore necessary. Present review describes the prevailing carbon footprinting methods and raises the related issues.

  18. Land, carbon and water footprints in Taiwan

    International Nuclear Information System (INIS)

    Lee, Yung-Jaan

    2015-01-01

    The consumer responsibility approach uses footprints as indicators of the total direct and indirect effects of a product or consumption activity. This study used a time-series analysis of three environmental pressures to quantify the total environmental pressures caused by consumption in Taiwan: land footprint, carbon footprint, and water footprint. Land footprint is the pressure from appropriation of biologically productive land and water area. Carbon footprint is the pressure from greenhouse gas emissions. Water footprint is the pressure from freshwater consumption. Conventional carbon footprint is the total CO 2 emitted by a certain activity or the CO 2 accumulation during a product life cycle. This definition cannot be used to convert CO 2 emissions into land units. This study responds to the needs of “CO 2 land” in the footprint family by applying the carbon footprint concept used by GFN. The analytical results showed that consumption by the average Taiwan citizen in 2000 required appropriation of 5.39 gha (hectares of land with global-average biological productivity) and 3.63 gha in 2011 in terms of land footprint. The average Taiwan citizen had a carbon footprint of 3.95 gha in 2000 and 5.94 gha in 2011. These results indicate that separately analyzing the land and carbon footprints enables their trends to be compared and appropriate policies and strategies for different sectors to be proposed accordingly. The average Taiwan citizen had a blue water footprint of 801 m 3 in 2000 and 784 m 3 in 2011. By comparison, their respective global averages were 1.23 gha, 2.36 gha and 163 m 3 blue water in 2011, respectively. Overall, Taiwan revealed higher environmental pressures compared to the rest of the world, demonstrating that Taiwan has become a high footprint state and has appropriated environmental resources from other countries. That is, through its imports of products with embodied pressures and its exports, Taiwan has transferred the environmental

  19. Land, carbon and water footprints in Taiwan

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yung-Jaan, E-mail: yungjaanlee@gmail.com

    2015-09-15

    The consumer responsibility approach uses footprints as indicators of the total direct and indirect effects of a product or consumption activity. This study used a time-series analysis of three environmental pressures to quantify the total environmental pressures caused by consumption in Taiwan: land footprint, carbon footprint, and water footprint. Land footprint is the pressure from appropriation of biologically productive land and water area. Carbon footprint is the pressure from greenhouse gas emissions. Water footprint is the pressure from freshwater consumption. Conventional carbon footprint is the total CO{sub 2} emitted by a certain activity or the CO{sub 2} accumulation during a product life cycle. This definition cannot be used to convert CO{sub 2} emissions into land units. This study responds to the needs of “CO{sub 2} land” in the footprint family by applying the carbon footprint concept used by GFN. The analytical results showed that consumption by the average Taiwan citizen in 2000 required appropriation of 5.39 gha (hectares of land with global-average biological productivity) and 3.63 gha in 2011 in terms of land footprint. The average Taiwan citizen had a carbon footprint of 3.95 gha in 2000 and 5.94 gha in 2011. These results indicate that separately analyzing the land and carbon footprints enables their trends to be compared and appropriate policies and strategies for different sectors to be proposed accordingly. The average Taiwan citizen had a blue water footprint of 801 m{sup 3} in 2000 and 784 m{sup 3} in 2011. By comparison, their respective global averages were 1.23 gha, 2.36 gha and 163 m{sup 3} blue water in 2011, respectively. Overall, Taiwan revealed higher environmental pressures compared to the rest of the world, demonstrating that Taiwan has become a high footprint state and has appropriated environmental resources from other countries. That is, through its imports of products with embodied pressures and its exports, Taiwan has

  20. Water Footprint Symposium: where next for water footprint and water assessment methodology?

    NARCIS (Netherlands)

    Tillotson, M.R.; Kiu, J.; Guan, D.; Wu, P.; Zhao, Xu; Zhang, Guoping; Pfister, S.; Pahlow, Markus

    2014-01-01

    Recognizing the need for a comprehensive review of the tools and metrics for the quantification and assessment of water footprints, and allowing for the opportunity for open discussion on the challenges and future of water footprinting methodology, an international symposium on water footprint was

  1. Water Footprint Symposium : where next for water footprint and water assessment methodology?

    NARCIS (Netherlands)

    Tillotson, Martin R.; Liu, Junguo; Guan, Dabo; Wu, Pute; Zhao, Xu; Zhang, Guoping; Pfister, Stephan; Pahlow, Markus

    2014-01-01

    Recognizing the need for a comprehensive review of the tools and metrics for the quantification and assessment of water footprints, and allowing for the opportunity for open discussion on the challenges and future of water footprinting methodology, an international symposium on water footprint was

  2. Properties of Highly Rotationally Excited H2 in Photodissociation Regions

    Science.gov (United States)

    Cummings, Sally Jane; Wan, Yier; Stancil, Phillip C.; Yang, Benhui H.; Zhang, Ziwei

    2018-06-01

    H2 is the dominant molecular species in the vast majority of interstellar environments and it plays a crucial role as a radiative coolant. In photodissociation regions, it is one of the primary emitters in the near to mid-infrared which are due to lines originating from highly excited rotational levels. However, collisional data for rotational levels j>10 are sparse, particularly for H2-H2 collisions. Utilizing new calculations for para-H2 and ortho-H2 collisional rate coefficients with H2 for j as high as 30, we investigate the effects of the new results in standard PDR models with the spectral simulation package Cloudy. We also perform Cloudy models of the Orion Bar and use Radex to explore rotational line ratio diagnostics. The resulting dataset of H2 collisional data should find wide application to other molecular environments. This work was support by Hubble Space Telescope grant HST-AR-13899.001-A and NASA grants NNX15AI61G and NNX16AF09G.

  3. Assessing Water and Carbon Footprints for Sustainable Water Resource Management

    Science.gov (United States)

    The key points of this presentation are: (1) Water footprint and carbon footprint as two sustainability attributes in adaptations to climate and socioeconomic changes, (2) Necessary to evaluate carbon and water footprints relative to constraints in resource capacity, (3) Critical...

  4. A comparison of footprint indexes calculated from ink and electronic footprints.

    Science.gov (United States)

    Urry, S R; Wearing, S C

    2001-04-01

    Pressure platforms offer the potential to measure and record electronic footprints rapidly; however, the accuracy of geometric indexes derived from these prints has not been investigated. A comparison of conventional ink footprints with simultaneously acquired electronic prints revealed significant differences in several geometric indexes. The contact area was consistently underestimated by the electronic prints and resulted in a significant change in the arch index. The long plantar angle was poorly correlated between techniques. This study demonstrated that electronic footprints, derived from a pressure platform, are not representative of the equivalent ink footprints and, consequently, should not be interpreted with reference to literature on conventional footprints.

  5. Green Chemistry Metrics with Special Reference to Green Analytical Chemistry

    Directory of Open Access Journals (Sweden)

    Marek Tobiszewski

    2015-06-01

    Full Text Available The concept of green chemistry is widely recognized in chemical laboratories. To properly measure an environmental impact of chemical processes, dedicated assessment tools are required. This paper summarizes the current state of knowledge in the field of development of green chemistry and green analytical chemistry metrics. The diverse methods used for evaluation of the greenness of organic synthesis, such as eco-footprint, E-Factor, EATOS, and Eco-Scale are described. Both the well-established and recently developed green analytical chemistry metrics, including NEMI labeling and analytical Eco-scale, are presented. Additionally, this paper focuses on the possibility of the use of multivariate statistics in evaluation of environmental impact of analytical procedures. All the above metrics are compared and discussed in terms of their advantages and disadvantages. The current needs and future perspectives in green chemistry metrics are also discussed.

  6. Green Chemistry Metrics with Special Reference to Green Analytical Chemistry.

    Science.gov (United States)

    Tobiszewski, Marek; Marć, Mariusz; Gałuszka, Agnieszka; Namieśnik, Jacek

    2015-06-12

    The concept of green chemistry is widely recognized in chemical laboratories. To properly measure an environmental impact of chemical processes, dedicated assessment tools are required. This paper summarizes the current state of knowledge in the field of development of green chemistry and green analytical chemistry metrics. The diverse methods used for evaluation of the greenness of organic synthesis, such as eco-footprint, E-Factor, EATOS, and Eco-Scale are described. Both the well-established and recently developed green analytical chemistry metrics, including NEMI labeling and analytical Eco-scale, are presented. Additionally, this paper focuses on the possibility of the use of multivariate statistics in evaluation of environmental impact of analytical procedures. All the above metrics are compared and discussed in terms of their advantages and disadvantages. The current needs and future perspectives in green chemistry metrics are also discussed.

  7. Sustainable Colombia : A Comprehensive Colombian Footprint Review

    OpenAIRE

    Brad Ewing

    2010-01-01

    During the past several months, the Ministry of Environment, Housing and Territorial Development of Colombia has been researching potential indicators that would be useful to assess and possibly adopt among which included the ecological footprint. This work was commissioned in order to provide the Ministry with a deeper understanding of the ecological footprint and to train a number of its...

  8. Water footprinting of dairy farming in Ireland

    NARCIS (Netherlands)

    Murphy, E.; Boer, de I.J.M.; Middelaar, van C.E.; Holden, N.M.; Shalloo, L.; Curran, T.P.; Upton, J.

    2017-01-01

    In the context of global water scarcity, water footprints have become an important sustainability indicator for food production systems. To improve the water footprint of the dairy sector, insight into freshwater consumption of individual farms is required. The objective of this study was to

  9. promoting sustainability by curtailing ecological footprints of

    African Journals Online (AJOL)

    The need to regulate land use and the exploitation of natural resources has led to the concept of sustainability, and by extension, ecological footprint (the total amount of land required by an individual to grow his/her needs). This paper examines ecological footprint savings in urban growth and housing development in ...

  10. Toward a nitrogen footprint calculator for Tanzania

    Science.gov (United States)

    Hutton, Mary Olivia; Leach, Allison M.; Leip, Adrian; Galloway, James N.; Bekunda, Mateete; Sullivan, Clare; Lesschen, Jan Peter

    2017-03-01

    We present the first nitrogen footprint model for a developing country: Tanzania. Nitrogen (N) is a crucial element for agriculture and human nutrition, but in excess it can cause serious environmental damage. The Sub-Saharan African nation of Tanzania faces a two-sided nitrogen problem: while there is not enough soil nitrogen to produce adequate food, excess nitrogen that escapes into the environment causes a cascade of ecological and human health problems. To identify, quantify, and contribute to solving these problems, this paper presents a nitrogen footprint tool for Tanzania. This nitrogen footprint tool is a concept originally designed for the United States of America (USA) and other developed countries. It uses personal resource consumption data to calculate a per-capita nitrogen footprint. The Tanzania N footprint tool is a version adapted to reflect the low-input, integrated agricultural system of Tanzania. This is reflected by calculating two sets of virtual N factors to describe N losses during food production: one for fertilized farms and one for unfertilized farms. Soil mining factors are also calculated for the first time to address the amount of N removed from the soil to produce food. The average per-capita nitrogen footprint of Tanzania is 10 kg N yr-1. 88% of this footprint is due to food consumption and production, while only 12% of the footprint is due to energy use. Although 91% of farms in Tanzania are unfertilized, the large contribution of fertilized farms to N losses causes unfertilized farms to make up just 83% of the food production N footprint. In a developing country like Tanzania, the main audiences for the N footprint tool are community leaders, planners, and developers who can impact decision-making and use the calculator to plan positive changes for nitrogen sustainability in the developing world.

  11. Far-infrared and submillimeter spectroscopy of photodissociation regions

    International Nuclear Information System (INIS)

    Qaiyum, A.

    1993-12-01

    The physical properties of the galactic and extragalactic photodissociation regions, warm gas components molecular clouds are, generally, derived through the far-infrared (FIR) fine structure and submillimeter line emissions arising out of these regions. In the theoretical studies of these lines the model of Tielens and Hollenbach (herein after referred as TH) are usually employed in which all the opacity is assumed local in escape probability formalism and inward directed photons do not escape. These assumptions are contrary to the observational facts, where most of the lines are found optically thin except OI (63 μm) and low rotational transitions of CO and some other molecules. The optically thin medium will allow the radiation to escape through any face of the region. These observational evidences let us to assume finite parallel plane slab, instead of semi-infinite parallel slab, in which the photons are allowed to escape from both surfaces (back and front). In the present study an attempt has been made to incorporate the two sided escape of photons from the PDRs and to study its effect on the FIR and submillimeter line emission from the PDRs/molecular clouds. Further the present formalism is also employed to study the clumpy PDRs/molecular clouds. The preliminary results show that now serious consequences are found on the thermal and chemical structure of the regions but individual line emissions are modified by differing factors. Particularly at low density and low kinetic temperature the change is substantial but at density greater than the critical density of the line and temperature close to the excitation temperature its effect is almost negligible. An attempt has also been made to study the physical conditions of the M17 region employing the present formalism. (author). 49 refs, 8 figs, 1 tab

  12. Atmospheric particulate matter within the Sudbury footprint

    Energy Technology Data Exchange (ETDEWEB)

    Koski, P. [Laurentian Univ., Sudbury, ON (Canada); Spiers, G.A. [Laurentian Univ., Sudbury, ON (Canada). Centre for Environmental Monitoring

    2007-07-01

    In order to assess health and risks to ecosystems, measuring exposure to coarse, fine and ultrafine dust and their association with metals in the air is necessary. This paper presented the results of a study that investigated the concentration, particle size distribution and spatial dispersion of metals in total and fractioned airborne dust. The study involved collection of airborne dust samples at five different sites over a one year period in the Sudbury area, including one control site located downwind of the south-westerly most industrial emission source. The paper discussed the goals and objectives of the project which included analysis of total concentration of particulate matter (PM) within various size fractions; analysis of concentration of selected metals such as arsenic, zinc, copper, nickel, cobalt, iron, manganese, chromium and lead as well as the species of sulphur within those size fractions; delineation between particle chemistry of both short and long range transport origin; determining the effects of the different seasons on PM concentrations, and establish any seasonal/temperature trends that may occur. The paper also discussed the methodology for the study with reference to sampling sites, sampling equipment, sampling schedule, mass determination, and chemical analysis. X-ray Fluorescence (XRF) was used to determine the total metals concentration in airborne dust. The results of the study were also presented. It was concluded that PM analysis within the Sudbury footprint indicated that the finer fractions primarily contained the highest weight and metal concentration. In addition, sulphate seemed to be the only species of sulphur present in the different size fractions at each site. 22 refs., 4 tabs., 5 figs.

  13. Atmospheric particulate matter within the Sudbury footprint

    International Nuclear Information System (INIS)

    Koski, P.; Spiers, G.A.

    2007-01-01

    In order to assess health and risks to ecosystems, measuring exposure to coarse, fine and ultrafine dust and their association with metals in the air is necessary. This paper presented the results of a study that investigated the concentration, particle size distribution and spatial dispersion of metals in total and fractioned airborne dust. The study involved collection of airborne dust samples at five different sites over a one year period in the Sudbury area, including one control site located downwind of the south-westerly most industrial emission source. The paper discussed the goals and objectives of the project which included analysis of total concentration of particulate matter (PM) within various size fractions; analysis of concentration of selected metals such as arsenic, zinc, copper, nickel, cobalt, iron, manganese, chromium and lead as well as the species of sulphur within those size fractions; delineation between particle chemistry of both short and long range transport origin; determining the effects of the different seasons on PM concentrations, and establish any seasonal/temperature trends that may occur. The paper also discussed the methodology for the study with reference to sampling sites, sampling equipment, sampling schedule, mass determination, and chemical analysis. X-ray Fluorescence (XRF) was used to determine the total metals concentration in airborne dust. The results of the study were also presented. It was concluded that PM analysis within the Sudbury footprint indicated that the finer fractions primarily contained the highest weight and metal concentration. In addition, sulphate seemed to be the only species of sulphur present in the different size fractions at each site. 22 refs., 4 tabs., 5 figs

  14. Radiation chemistry

    International Nuclear Information System (INIS)

    Rodgers, F.; Rodgers, M.A.

    1987-01-01

    The contents of this book include: Interaction of ionizing radiation with matter; Primary products in radiation chemistry; Theoretical aspects of radiation chemistry; Theories of the solvated electron; The radiation chemistry of gases; Radiation chemistry of colloidal aggregates; Radiation chemistry of the alkali halides; Radiation chemistry of polymers; Radiation chemistry of biopolymers; Radiation processing and sterilization; and Compound index

  15. ASSESSMENT OF HOUSEHOLD CARBON FOOTPRINT REDUCTION POTENTIALS

    Energy Technology Data Exchange (ETDEWEB)

    Kramer, Klaas Jan; Homan, Greg; Brown, Rich; Worrell, Ernst; Masanet, Eric

    2009-04-15

    The term ?household carbon footprint? refers to the total annual carbon emissions associated with household consumption of energy, goods, and services. In this project, Lawrence Berkeley National Laboratory developed a carbon footprint modeling framework that characterizes the key underlying technologies and processes that contribute to household carbon footprints in California and the United States. The approach breaks down the carbon footprint by 35 different household fuel end uses and 32 different supply chain fuel end uses. This level of end use detail allows energy and policy analysts to better understand the underlying technologies and processes contributing to the carbon footprint of California households. The modeling framework was applied to estimate the annual home energy and supply chain carbon footprints of a prototypical California household. A preliminary assessment of parameter uncertainty associated with key model input data was also conducted. To illustrate the policy-relevance of this modeling framework, a case study was conducted that analyzed the achievable carbon footprint reductions associated with the adoption of energy efficient household and supply chain technologies.

  16. The Water Footprint of Food Aid

    Directory of Open Access Journals (Sweden)

    Nicole Jackson

    2015-05-01

    Full Text Available Food aid is a critical component of the global food system, particularly when emergency situations arise. For the first time, we evaluate the water footprint of food aid. To do this, we draw on food aid data from theWorld Food Programme and virtual water content estimates from WaterStat. We find that the total water footprint of food aid was 10 km3 in 2005, which represents approximately 0.5% of the water footprint of food trade and 2.0% of the water footprint of land grabbing (i.e., water appropriation associated with large agricultural land deals. The United States is by far the largest food aid donor and contributes 82% of the water footprint of food aid. The countries that receive the most water embodied in aid are Ethiopia, Sudan, North Korea, Bangladesh and Afghanistan. Notably, we find that there is significant overlap between countries that receive food aid and those that have their land grabbed. Multivariate regression results indicate that donor water footprints are driven by political and environmental variables, whereas recipient water footprints are driven by land grabbing and food indicators.

  17. Assessing Water and Carbon Footprints for Green Water Resource Management

    Science.gov (United States)

    This slide presentation will focus on the following points: (1) Water footprint and carbon footprint are two criteria evaluating the greenness in urban development, (2) Two cases are examined and presented: water footprints in energy productions and carbon footprints in water ...

  18. Kinetics of photodissociated oxygen recombination to human oxyhemoglobin

    International Nuclear Information System (INIS)

    Bokut', S.B.; Syakhovich, V.E.; Parul', D.A.; Lepeshkevich, S.V.; Dzhagarov, B.M.

    2001-01-01

    Oxygen binding to the tetrameric hemoglobin (Hb) is a basic reaction for study of a cooperativity and allosteric homotropic and heterotropic interactions in proteins. In tetrameric hemoglobin the certain sites in the α 1 β 2 -interface have the precise geometry and chemical reactivity to bind 2,3-diphosphoglycerate, protons, chloride and hence shift the equilibrium away from the oxyconformation, thereby favoring O 2 release. Post-translational modifications of the major hemoglobin fraction Hb A 1 with sugar moiety in the Hb central cavity leads to differences in geometry of the effectors binding region providing a useful experimental tool to study the long range relationship in the tetramer molecule. Here we present the results of the nongeminate biomolecular association of Hb and O 2 obtained by nanosecond laser flash-photolysis. All measurements were carried out in 50 mM potassium-phosphate buffer pH 7.4 with the following samples Hb A 1 , HbA 1c , HbA 1b , and HbA 1 in the presence of the tenfold excess of inositol hexaphosphate (IHP). Our results show that oxygen recombination kinetics are characterized by two processes with different decay times and Hb-form-dependent contributions. This process can be described by the following expression: A(t)=A 1 exp(-t/τ 1 )+A 2 exp(-t/τ 2 ), where A(t) is a normalized number of the deoxy-Hb molecules. The short-live component has a lifetime τ 1 , which is Hb-type dependent and changes in the intervals 30-60 μs, the second component has a lifetime τ 2 around 100 μs, and also is sample-dependent value. A(t=0) is proportional to apparent quantum yields of the photodissociation and determines by geminate stages of oxygen binding to Fe from the protein matrix areas. These results show that post-translational modifications of the major hemoglobin component HbA 1 have influence on hemoglobin transport function via the long range relationship in the tetramer molecule

  19. Water footprint and carbon footprint of the energy consumption in sunflower agroecosystems.

    Science.gov (United States)

    Yousefi, Mohammad; Khoramivafa, Mahmud; Damghani, Abdolmajid Mahdavi

    2017-08-01

    The aims of this study were to assess the energy requirements, carbon footprint, and water footprint of sunflower production in Kermanshah province, western Iran. Data were collected from 70 sunflower production agroecosystems which were selected based on random sampling method in summer 2012. Results indicated that total input and output energy in sunflower production were 26,973.87 and 64,833.92 MJha -1 , respectively. The highest share of total input energy in sunflower agroecosystems was recorded for electricity power, N fertilizer, and diesel fuel with 35, 19, and 17%, respectively. Also, energy use efficiency, water footprint, greenhouse gas (GHG) emission, and carbon footprint were calculated as 2.40, 3.41 m 3  kg -1 , 2042.091 kg CO 2eq ha -1 , and 0.875 kg CO 2eq kg -1 , respectively. 0.18 of sunflower water footprint was related to green water footprint and the remaining 82% was related to blue water footprint. Also, the highest share of carbon footprint was related to electricity power (nearby 80%). Due to the results of this study, reducing use of fossil fuel and non-renewable energy resource and application of sufficient irrigation systems by efficient use of water resource are essential in order to achieve low carbon footprint, environmental challenges, and also sustainability of agricultural production systems.

  20. FOOTPRINTS FOR SUSTAINABILITY: THE NEXT STEPS

    Science.gov (United States)

    This paper discusses the strengths and weaknesses of the ecological footprint as an ecological accounting method, points out research needs for improvement of the analysis, and suggests potential new applications.

  1. Carbon Footprint Calculator | Climate Change | US EPA

    Science.gov (United States)

    2016-12-12

    An interactive calculator to estimate your household's carbon footprint. This tool will estimate carbon pollution emissions from your daily activities and show how to reduce your emissions and save money through simple steps.

  2. Carbon footprinting. An introduction for organisations

    International Nuclear Information System (INIS)

    2007-08-01

    To some degree or other, every person and every organisation, either directly or indirectly, is responsible for producing carbon dioxide gas which finds its way into the atmosphere and therefore contributes to the greenhouse effect. The amount of carbon dioxide produced by a person, an organisation, a company, an industry, an event, or even a population can be quantified in what is now described as a carbon footprint. Gases other than carbon dioxide are also released to the atmosphere through man's activities and these can also be evaluated in terms of the carbon footprint. This document explains the meaning of the expression 'carbon footprint' and aims to assist businesses and organisations to determine collective and individual carbon footprints

  3. Photodissociation of H2+ by a ruby laser with ion energy analysis of ejected H+

    International Nuclear Information System (INIS)

    Ozenne, J.B.; Pham, D.; Tadjeddine, M.; Durup, J.

    1974-01-01

    The kinetic energy released in the photodissociation of H 2 + by a ruby laser beam has been measured. The spectrum of the dissociation kinetic energy of H + +H shows several vibrational levels, and after deconvolution due to the energetic and angular resolution of the apparatus, gives a population of those vibrational levels, close to theoretical population [fr

  4. Photodissociation of OCS: Deviations between theory and experiment, and the importance of higher order correlation effects

    DEFF Research Database (Denmark)

    Schmidt, Johan Albrecht; Olsen, Jógvan Magnus Haugaard

    2014-01-01

    The photodissociation of carbonyl sulfide (OCS) was investigated theoretically in a series of studies by Schmidt and co-workers. Initial studies [J. A. Schmidt, M. S. Johnson, G. C. McBane, and R. Schinke, J. Chem. Phys.136, 131101 (2012);J. A. Schmidt, M. S. Johnson, G. C. McBane, and R. Schinke...

  5. UV Photodissociation Action Spectroscopy of Haloanilinium Ions in a Linear Quadrupole Ion Trap Mass Spectrometer

    Science.gov (United States)

    Hansen, Christopher S.; Kirk, Benjamin B.; Blanksby, Stephen J.; O'Hair, Richard. A. J.; Trevitt, Adam J.

    2013-06-01

    UV-vis photodissociation action spectroscopy is becoming increasingly prevalent because of advances in, and commercial availability of, ion trapping technologies and tunable laser sources. This study outlines in detail an instrumental arrangement, combining a commercial ion-trap mass spectrometer and tunable nanosecond pulsed laser source, for performing fully automated photodissociation action spectroscopy on gas-phase ions. The components of the instrumentation are outlined, including the optical and electronic interfacing, in addition to the control software for automating the experiment and performing online analysis of the spectra. To demonstrate the utility of this ensemble, the photodissociation action spectra of 4-chloroanilinium, 4-bromoanilinium, and 4-iodoanilinium cations are presented and discussed. Multiple photoproducts are detected in each case and the photoproduct yields are followed as a function of laser wavelength. It is shown that the wavelength-dependent partitioning of the halide loss, H loss, and NH3 loss channels can be broadly rationalized in terms of the relative carbon-halide bond dissociation energies and processes of energy redistribution. The photodissociation action spectrum of (phenyl)Ag2 + is compared with a literature spectrum as a further benchmark.

  6. Water footprint of hydro power in Norway

    Science.gov (United States)

    Engeland, Kolbjørn; Tallaksen, Lena; Haakon Bakken, Tor; Killingtveit, Ånund

    2015-04-01

    The IPCC Special Report on Renewable Energy (IPCC, 2012) assesses the potential for renewable energy sources to replace fossil-based fuels and benchmarks the technologies with respect to a set of criteria, including their water footprint measured as m3/MWh. While most of the renewable technologies show a typical range of 1-5 m3/MWh, the very sparse data on hydropower range from a minimum of 0.04 to a maximum of 209 m3/MWh. More recent studies on water footprint from hydropower indicate that the water consumption rates could go even far beyond the numbers published by IPCC (2012). The methodological approach behind these numbers are, however, criticized as it appears over-simplistic and several issues need to be defined and clarified in order to present the 'true picture' of the water footprint of hydropower. Despite this, the rather high numbers for hydropower may imply a reputational risk for the sector and also be a direct investment risk in new projects if hydropower is considered a "large-scale water consumer". Estimation of water footprint has two important components (i) definition of water footprint (including system boundaries), and (ii) estimation of evaporation, which is assumed to constitute the main water loss from hydropower. Here we will mainly address the second topic and have chosen to use a water footprint definition based on net evapotranspiration from reservoirs. Thus, we need estimates of evapotranspiration from the land surface prior to inundation and the evaporation from the reservoir after it has been filled up. The primary objective of the study is to estimate water footprint of hydropower in Norway and in particular to answer the following questions: (i) How does different environmental variables influence water footprint estimation in Norway?, and in particular (ii) What is the total/specific water footprint from Norwegian hydropower production? To answer these questions we tested how environmental variables like climate and vegetation

  7. Spotting Cheetahs: Identifying Individuals by Their Footprints.

    Science.gov (United States)

    Jewell, Zoe C; Alibhai, Sky K; Weise, Florian; Munro, Stuart; Van Vuuren, Marlice; Van Vuuren, Rudie

    2016-05-01

    The cheetah (Acinonyx jubatus) is Africa's most endangered large felid and listed as Vulnerable with a declining population trend by the IUCN(1). It ranges widely over sub-Saharan Africa and in parts of the Middle East. Cheetah conservationists face two major challenges, conflict with landowners over the killing of domestic livestock, and concern over range contraction. Understanding of the latter remains particularly poor(2). Namibia is believed to support the largest number of cheetahs of any range country, around 30%, but estimates range from 2,905(3) to 13,520(4). The disparity is likely a result of the different techniques used in monitoring. Current techniques, including invasive tagging with VHF or satellite/GPS collars, can be costly and unreliable. The footprint identification technique(5) is a new tool accessible to both field scientists and also citizens with smartphones, who could potentially augment data collection. The footprint identification technique analyzes digital images of footprints captured according to a standardized protocol. Images are optimized and measured in data visualization software. Measurements of distances, angles, and areas of the footprint images are analyzed using a robust cross-validated pairwise discriminant analysis based on a customized model. The final output is in the form of a Ward's cluster dendrogram. A user-friendly graphic user interface (GUI) allows the user immediate access and clear interpretation of classification results. The footprint identification technique algorithms are species specific because each species has a unique anatomy. The technique runs in a data visualization software, using its own scripting language (jsl) that can be customized for the footprint anatomy of any species. An initial classification algorithm is built from a training database of footprints from that species, collected from individuals of known identity. An algorithm derived from a cheetah of known identity is then able to classify

  8. Spatially and temporally explicit water footprint accounting

    OpenAIRE

    Mekonnen, Mesfin

    2011-01-01

    The earth’s freshwater resources are subject to increasing pressure in the form of consumptive water use and pollution (Postel, 2000; WWAP, 2003, 2006, 2009). Quantitative assessment of the green, blue and grey water footprint of global production and consumption can be regarded as a key in understanding the pressure put on the global freshwater resources. The overall objective of this thesis is, therefore, to analyse the spatial and temporal pattern of the water footprint of humans from both...

  9. Spotting Cheetahs: Identifying Individuals by Their Footprints

    Science.gov (United States)

    Jewell, Zoe C.; Alibhai, Sky K.; Weise, Florian; Munro, Stuart; Van Vuuren, Marlice; Van Vuuren, Rudie

    2016-01-01

    The cheetah (Acinonyx jubatus) is Africa's most endangered large felid and listed as Vulnerable with a declining population trend by the IUCN1. It ranges widely over sub-Saharan Africa and in parts of the Middle East. Cheetah conservationists face two major challenges, conflict with landowners over the killing of domestic livestock, and concern over range contraction. Understanding of the latter remains particularly poor2. Namibia is believed to support the largest number of cheetahs of any range country, around 30%, but estimates range from 2,9053 to 13,5204. The disparity is likely a result of the different techniques used in monitoring. Current techniques, including invasive tagging with VHF or satellite/GPS collars, can be costly and unreliable. The footprint identification technique5 is a new tool accessible to both field scientists and also citizens with smartphones, who could potentially augment data collection. The footprint identification technique analyzes digital images of footprints captured according to a standardized protocol. Images are optimized and measured in data visualization software. Measurements of distances, angles, and areas of the footprint images are analyzed using a robust cross-validated pairwise discriminant analysis based on a customized model. The final output is in the form of a Ward's cluster dendrogram. A user-friendly graphic user interface (GUI) allows the user immediate access and clear interpretation of classification results. The footprint identification technique algorithms are species specific because each species has a unique anatomy. The technique runs in a data visualization software, using its own scripting language (jsl) that can be customized for the footprint anatomy of any species. An initial classification algorithm is built from a training database of footprints from that species, collected from individuals of known identity. An algorithm derived from a cheetah of known identity is then able to classify free

  10. The material footprint of nations.

    Science.gov (United States)

    Wiedmann, Thomas O; Schandl, Heinz; Lenzen, Manfred; Moran, Daniel; Suh, Sangwon; West, James; Kanemoto, Keiichiro

    2015-05-19

    Metrics on resource productivity currently used by governments suggest that some developed countries have increased the use of natural resources at a slower rate than economic growth (relative decoupling) or have even managed to use fewer resources over time (absolute decoupling). Using the material footprint (MF), a consumption-based indicator of resource use, we find the contrary: Achievements in decoupling in advanced economies are smaller than reported or even nonexistent. We present a time series analysis of the MF of 186 countries and identify material flows associated with global production and consumption networks in unprecedented specificity. By calculating raw material equivalents of international trade, we demonstrate that countries' use of nondomestic resources is, on average, about threefold larger than the physical quantity of traded goods. As wealth grows, countries tend to reduce their domestic portion of materials extraction through international trade, whereas the overall mass of material consumption generally increases. With every 10% increase in gross domestic product, the average national MF increases by 6%. Our findings call into question the sole use of current resource productivity indicators in policy making and suggest the necessity of an additional focus on consumption-based accounting for natural resource use.

  11. Atmospheric mercury footprints of nations.

    Science.gov (United States)

    Liang, Sai; Wang, Yafei; Cinnirella, Sergio; Pirrone, Nicola

    2015-03-17

    The Minamata Convention was established to protect humans and the natural environment from the adverse effects of mercury emissions. A cogent assessment of mercury emissions is required to help implement the Minamata Convention. Here, we use an environmentally extended multi-regional input-output model to calculate atmospheric mercury footprints of nations based on upstream production (meaning direct emissions from the production activities of a nation), downstream production (meaning both direct and indirect emissions caused by the production activities of a nation), and consumption (meaning both direct and indirect emissions caused by final consumption of goods and services in a nation). Results show that nations function differently within global supply chains. Developed nations usually have larger consumption-based emissions than up- and downstream production-based emissions. India, South Korea, and Taiwan have larger downstream production-based emissions than their upstream production- and consumption-based emissions. Developed nations (e.g., United States, Japan, and Germany) are in part responsible for mercury emissions of developing nations (e.g., China, India, and Indonesia). Our findings indicate that global mercury abatement should focus on multiple stages of global supply chains. We propose three initiatives for global mercury abatement, comprising the establishment of mercury control technologies of upstream producers, productivity improvement of downstream producers, and behavior optimization of final consumers.

  12. Carbon footprint of electronic devices

    Science.gov (United States)

    Sloma, Marcin

    2013-07-01

    Paper assesses the greenhouse gas emissions related to the electronic sectors including information and communication technology and media sectors. While media often presents the carbon emission problem of other industries like petroleum industry, the airlines and automobile sectors, plastics and steel manufacturers, the electronics industry must include the increasing carbon footprints caused from their applications like media and entertainment, computers and cooling devices, complex telecommunications networks, cloud computing and powerful mobile phones. In that sense greenhouse gas emission of electronics should be studied in a life cycle perspective, including regular operational electricity use. Paper presents which product groups or processes are major contributors in emission. From available data and extrapolation of existing information we know that the information and communication technology sector produced 1.3% and media sector 1.7% of global gas emissions within production cycle, using the data from 2007.In the same time global electricity use of that sectors was 3.9% and 3.2% respectively. The results indicate that for both sectors operation leads to more gas emissions than manufacture, although impacts from the manufacture is significant, especially in the supply chain. Media electronics led to more emissions than PCs (manufacture and operation). Examining the role of electronics in climate change, including disposal of its waste, will enable the industry to take internal actions, leading to lowering the impact on the climate change within the sector itself.

  13. Unrealistic phylogenetic trees may improve phylogenetic footprinting.

    Science.gov (United States)

    Nettling, Martin; Treutler, Hendrik; Cerquides, Jesus; Grosse, Ivo

    2017-06-01

    The computational investigation of DNA binding motifs from binding sites is one of the classic tasks in bioinformatics and a prerequisite for understanding gene regulation as a whole. Due to the development of sequencing technologies and the increasing number of available genomes, approaches based on phylogenetic footprinting become increasingly attractive. Phylogenetic footprinting requires phylogenetic trees with attached substitution probabilities for quantifying the evolution of binding sites, but these trees and substitution probabilities are typically not known and cannot be estimated easily. Here, we investigate the influence of phylogenetic trees with different substitution probabilities on the classification performance of phylogenetic footprinting using synthetic and real data. For synthetic data we find that the classification performance is highest when the substitution probability used for phylogenetic footprinting is similar to that used for data generation. For real data, however, we typically find that the classification performance of phylogenetic footprinting surprisingly increases with increasing substitution probabilities and is often highest for unrealistically high substitution probabilities close to one. This finding suggests that choosing realistic model assumptions might not always yield optimal predictions in general and that choosing unrealistically high substitution probabilities close to one might actually improve the classification performance of phylogenetic footprinting. The proposed PF is implemented in JAVA and can be downloaded from https://github.com/mgledi/PhyFoo. : martin.nettling@informatik.uni-halle.de. Supplementary data are available at Bioinformatics online. © The Author 2017. Published by Oxford University Press.

  14. Presidential Green Chemistry Challenge: 2015 Specific Environmental Benefit: Climate Change Award

    Science.gov (United States)

    Presidential Green Chemistry Challenge 2015 award winner, Algenol, blue-green algae to produce ethanol and other fuels, uses CO2 from air or industrial emitters, reduces the carbon footprint, costs and water usage, no reliance on food crops

  15. National water footprint accounts: the green, blue and grey water footprint of production and consumption

    NARCIS (Netherlands)

    Mekonnen, Mesfin; Hoekstra, Arjen Ysbert

    2011-01-01

    This study quantifies and maps the water footprints of nations from both a production and consumption perspective and estimates international virtual water flows and national and global water savings as a result of trade. The entire estimate includes a breakdown of water footprints, virtual water

  16. Photoinduced Processes in Hydrogen Bonded System: Photodissociation of Imidazole Clusters

    Czech Academy of Sciences Publication Activity Database

    Poterya, Viktoriya; Profant, V.; Fárník, Michal; Šištík, L.; Slavíček, P.; Buck, U.

    2009-01-01

    Roč. 113, č. 52 (2009), s. 14583-14590 ISSN 1089-5639 R&D Projects: GA AV ČR KAN400400651; GA AV ČR KJB400400902; GA ČR GA203/09/0422 Institutional research plan: CEZ:AV0Z40400503 Keywords : scattering analysis * molecules * imidazole clusters Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.899, year: 2009

  17. Photo-electron spectroscopy using synchrotron radiation of molecular radicals and fragments produced by laser photo-dissociation

    International Nuclear Information System (INIS)

    Nahon, Laurent

    1991-01-01

    This research thesis reports the combined use of a laser and of a synchrotron radiation in order to respectively photo-dissociate a molecule and to photo-ionize fragments which are analysed by photo-electron spectroscopy. This association allows, on the one hand, radical photo-ionization to be studied, and, on the other hand, polyatomic molecule photo-dissociation to be studied. The author studied the photo-excitation and/or photo-ionization in layer 4d (resp. 3d) of atomic iodine (resp. bromine) produced almost complete laser photo-dissociation of I_2 (resp. Br_2). He discuses the processes of relaxation of transitions from valence 4d to 5p (resp. 3d to 4p) which occur either by direct self-ionization or by resonant Auger effect, and reports the study of photo-dissociation of s-tetrazine (C_2N_4H_2) [fr

  18. Nitrogen footprints: past, present and future

    Science.gov (United States)

    Galloway, James N.; Winiwarter, Wilfried; Leip, Adrian; Leach, Allison M.; Bleeker, Albert; Willem Erisman, Jan

    2014-11-01

    The human alteration of the nitrogen cycle has evolved from minimal in the mid-19th century to extensive in the present time. The consequences to human and environmental health are significant. While much attention has been given to the extent and impacts of the alteration, little attention has been given to those entities (i.e., consumers, institutions) that use the resources that result in extensive reactive nitrogen (Nr) creation. One strategy for assessment is the use of nitrogen footprint tools. A nitrogen footprint is generally defined as the total amount of Nr released to the environment as a result of an entity’s consumption patterns. This paper reviews a number of nitrogen footprint tools (N-Calculator, N-Institution, N-Label, N-Neutrality, N-Indicator) that are designed to provide that attention. It reviews N-footprint tools for consumers as a function of the country that they live in (N-Calculator, N-Indicator) and the products they buy (N-Label), for the institutions that people work in and are educated in (N-Institution), and for events and decision-making regarding offsets (N-Neutrality). N footprint tools provide a framework for people to make decisions about their resource use and show them how offsets can be coupled with behavior change to decrease consumer/institution contributions to N-related problems.

  19. Carbon footprint of a music festival

    Science.gov (United States)

    Schafer, K. V.

    2009-12-01

    In an effort to curb CO2 and by extension, greenhouse gas emissions various initiatives have been taken statewide, nationally and internationally. However, benchmarks and metrics are not clearly defined for CO2 and CO2 equivalent accounting. The objective of this study is to estimate the carbon footprint of the Lincoln Park Music Festival which occurs annually in Newark, NJ. This festival runs for three days each summer and consists of music, food vendors, merchandise and a green marketplace. In order to determine the carbon footprint generated by transportation, surveys of participants were analyzed. Of the approximately 40,000 participants in 2009, 3.3% were surveyed. About 30% of respondents commuted to the festival by car with an average of 10 miles traveling distance. Transportation emission amounted to an estimated CO2 emission of 188 metric tons for all three days combined. Trash at the music festival was weighed, components estimated, and potential CO2 emission calculated if incinerated. 63% of the trash was found to be carbon based, which is the equivalent of three metric tons of CO2 if incinerated. The majority of the trash (>60%) could have been recycled, thus significantly reducing the carbon footprint. In order to limit the carbon footprint of this festival, alternative transport options would be advisable as transport accounted for the largest proportion of the carbon footprint at this festival.

  20. Mapping the Carbon Footprint of Nations.

    Science.gov (United States)

    Kanemoto, Keiichiro; Moran, Daniel; Hertwich, Edgar G

    2016-10-04

    Life cycle thinking asks companies and consumers to take responsibility for emissions along their entire supply chain. As the world economy becomes more complex it is increasingly difficult to connect consumers and other downstream users to the origins of their greenhouse gas (GHG) emissions. Given the important role of subnational entities-cities, states, and companies-in GHG abatement efforts, it would be advantageous to better link downstream users to facilities and regulators who control primary emissions. We present a new spatially explicit carbon footprint method for establishing such connections. We find that for most developed countries the carbon footprint has diluted and spread: for example, since 1970 the U.S. carbon footprint has grown 23% territorially, and 38% in consumption-based terms, but nearly 200% in spatial extent (i.e., the minimum area needed to contain 90% of emissions). The rapidly growing carbon footprints of China and India, however, do not show such a spatial expansion of their consumption footprints in spite of their increasing participation in the world economy. In their case, urbanization concentrates domestic pollution and this offsets the increasing importance of imports.

  1. Carbon footprint of grain production in China.

    Science.gov (United States)

    Zhang, Dan; Shen, Jianbo; Zhang, Fusuo; Li, Yu'e; Zhang, Weifeng

    2017-06-29

    Due to the increasing environmental impact of food production, carbon footprint as an indicator can guide farmland management. This study established a method and estimated the carbon footprint of grain production in China based on life cycle analysis (LCA). The results showed that grain production has a high carbon footprint in 2013, i.e., 4052 kg ce/ha or 0.48 kg ce/kg for maize, 5455 kg ce/ha or 0.75 kg ce/kg for wheat and 11881 kg ce/ha or 1.60 kg ce/kg for rice. These footprints are higher than that of other countries, such as the United States, Canada and India. The most important factors governing carbon emissions were the application of nitrogen fertiliser (8-49%), straw burning (0-70%), energy consumption by machinery (6-40%), energy consumption for irrigation (0-44%) and CH 4 emissions from rice paddies (15-73%). The most important carbon sequestration factors included returning of crop straw (41-90%), chemical nitrogen fertiliser application (10-59%) and no-till farming practices (0-10%). Different factors dominated in different crop systems in different regions. To identity site-specific key factors and take countermeasures could significantly lower carbon footprint, e.g., ban straw burning in northeast and south China, stopping continuous flooding irrigation in wheat and rice production system.

  2. Nitrogen footprints: past, present and future

    International Nuclear Information System (INIS)

    Galloway, James N; Leach, Allison M; Winiwarter, Wilfried; Leip, Adrian; Bleeker, Albert; Erisman, Jan Willem

    2014-01-01

    The human alteration of the nitrogen cycle has evolved from minimal in the mid-19th century to extensive in the present time. The consequences to human and environmental health are significant. While much attention has been given to the extent and impacts of the alteration, little attention has been given to those entities (i.e., consumers, institutions) that use the resources that result in extensive reactive nitrogen (Nr) creation. One strategy for assessment is the use of nitrogen footprint tools. A nitrogen footprint is generally defined as the total amount of Nr released to the environment as a result of an entity’s consumption patterns. This paper reviews a number of nitrogen footprint tools (N-Calculator, N-Institution, N-Label, N-Neutrality, N-Indicator) that are designed to provide that attention. It reviews N-footprint tools for consumers as a function of the country that they live in (N-Calculator, N-Indicator) and the products they buy (N-Label), for the institutions that people work in and are educated in (N-Institution), and for events and decision-making regarding offsets (N-Neutrality). N footprint tools provide a framework for people to make decisions about their resource use and show them how offsets can be coupled with behavior change to decrease consumer/institution contributions to N-related problems. (paper)

  3. The Photodissociation of HCN and HNC: Effects on the HNC/HCN Abundance Ratio in the Interstellar Medium

    Energy Technology Data Exchange (ETDEWEB)

    Aguado, Alfredo [Departamento de Química Física Aplicada (UAM), Unidad Asociada a IFF-CSIC, Facultad de Ciencias Módulo 14, Universidad Autónoma de Madrid, E-28049, Madrid (Spain); Roncero, Octavio; Zanchet, Alexandre [Instituto de Física Fundamental (IFF-CSIC), C.S.I.C., Serrano 123, E-28006 Madrid (Spain); Agúndez, Marcelino; Cernicharo, José, E-mail: octavio.roncero@csic.es [Instituto de Ciencia de Materiales de Madrid, CSIC, C/ Sor Juana Inés de la Cruz 3, Cantoblanco E-28049 (Spain)

    2017-03-20

    The impact of the photodissociation of HCN and HNC isomers is analyzed in different astrophysical environments. For this purpose, the individual photodissociation cross sections of HCN and HNC isomers have been calculated in the 7–13.6 eV photon energy range for a temperature of 10 K. These calculations are based on the ab initio calculation of three-dimensional adiabatic potential energy surfaces of the 21 lower electronic states. The cross sections are then obtained using a quantum wave packet calculation of the rotational transitions needed to simulate a rotational temperature of 10 K. The cross section calculated for HCN shows significant differences with respect to the experimental one, and this is attributed to the need to consider non-adiabatic transitions. Ratios between the photodissociation rates of HCN and HNC under different ultraviolet radiation fields have been computed by renormalizing the rates to the experimental value. It is found that HNC is photodissociated faster than HCN by a factor of 2.2 for the local interstellar radiation field and 9.2 for the solar radiation field, at 1 au. We conclude that to properly describe the HNC/HCN abundance ratio in astronomical environments illuminated by an intense ultraviolet radiation field, it is necessary to use different photodissociation rates for each of the two isomers, which are obtained by integrating the product of the photodissociation cross sections and ultraviolet radiation field over the relevant wavelength range.

  4. Bad chemistry

    OpenAIRE

    Petsko, Gregory A

    2004-01-01

    General chemistry courses haven't changed significantly in forty years. Because most basic chemistry students are premedical students, medical schools have enormous influence and could help us start all over again to create undergraduate chemistry education that works.

  5. The carbon footprint of global tourism

    Science.gov (United States)

    Lenzen, Manfred; Sun, Ya-Yen; Faturay, Futu; Ting, Yuan-Peng; Geschke, Arne; Malik, Arunima

    2018-06-01

    Tourism contributes significantly to global gross domestic product, and is forecast to grow at an annual 4%, thus outpacing many other economic sectors. However, global carbon emissions related to tourism are currently not well quantified. Here, we quantify tourism-related global carbon flows between 160 countries, and their carbon footprints under origin and destination accounting perspectives. We find that, between 2009 and 2013, tourism's global carbon footprint has increased from 3.9 to 4.5 GtCO2e, four times more than previously estimated, accounting for about 8% of global greenhouse gas emissions. Transport, shopping and food are significant contributors. The majority of this footprint is exerted by and in high-income countries. The rapid increase in tourism demand is effectively outstripping the decarbonization of tourism-related technology. We project that, due to its high carbon intensity and continuing growth, tourism will constitute a growing part of the world's greenhouse gas emissions.

  6. Silk industry and carbon footprint mitigation

    Science.gov (United States)

    Giacomin, A. M.; Garcia, J. B., Jr.; Zonatti, W. F.; Silva-Santos, M. C.; Laktim, M. C.; Baruque-Ramos, J.

    2017-10-01

    Currently there is a concern with issues related to sustainability and more conscious consumption habits. The carbon footprint measures the total amount of greenhouse gas (GHG) emissions produced directly and indirectly by human activities and is usually expressed in tonnes of carbon dioxide (CO2) equivalents. The present study takes into account data collected in scientific literature regarding the carbon footprint, garments produced with silk fiber and the role of mulberry as a CO2 mitigation tool. There is an indication of a positive correlation between silk garments and carbon footprint mitigation when computed the cultivation of mulberry trees in this calculation. A field of them mitigates CO2 equivalents in a proportion of 735 times the weight of the produced silk fiber by the mulberry cultivated area. At the same time, additional researches are needed in order to identify and evaluate methods to advertise this positive correlation in order to contribute to a more sustainable fashion industry.

  7. Photodissociation action spectroscopy of ozonized films of undecylenic acid

    Science.gov (United States)

    Gomez, Anthony; Li, Ao; Wlaser, Maggie; Britigan, Nicole; Nizkorodov, Sergey

    2005-03-01

    Photochemical studies of thin films of oxidized undecylenic acid and its salts will be presented. The films are first partially oxidized by ozone, and then irradiated with a wavelength tunable UV source in an inert atmosphere. The escaping gas-phase photochemical products are detected by cavity ring-down spectroscopy as a function of the excitation frequency. The film composition is analyzed by chromatography and mass spectrometry. The data provide critical new insights into the mechanisms of ozonolysis and photolysis of oxidized undecylenic acid, and have serious implications for atmospheric chemistry of organic aerosol particles.

  8. The carbon footprint of cataract surgery.

    Science.gov (United States)

    Morris, D S; Wright, T; Somner, J E A; Connor, A

    2013-04-01

    Climate change is predicted to be one of the largest global health threats of the 21st century. Health care itself is a large contributor to carbon emissions. Determining the carbon footprint of specific health care activities such as cataract surgery allows the assessment of associated emissions and identifies opportunities for reduction. To assess the carbon footprint of a cataract pathway in a British teaching hospital. This was a component analysis study for one patient having first eye cataract surgery in the University Hospital of Wales, Cardiff. Activity data was collected from three sectors, building and energy use, travel and procurement. Published emissions factors were applied to this data to provide figures in carbon dioxide equivalents (CO2eq). The carbon footprint for one cataract operation was 181.8 kg CO2eq. On the basis that 2230 patients were treated for cataracts during 2011 in Cardiff, this has an associated carbon footprint of 405.4 tonnes CO2eq. Building and energy use was estimated to account for 36.1% of overall emissions, travel 10.1% and procurement 53.8%, with medical equipment accounting for the most emissions at 32.6%. This is the first published carbon footprint of cataract surgery and acts as a benchmark for other studies as well as identifying areas for emissions reduction. Within the procurement sector, dialogue with industry is important to reduce the overall carbon footprint. Sustainability should be considered when cataract pathways are designed as there is potential for reduction in all sectors with the possible side effects of saving costs and improving patient care.

  9. Exceptional preservation of children's footprints from a Holocene footprint site in Namibia

    Science.gov (United States)

    Bennett, Matthew R.; Morse, Sarita A.; Liutkus-Pierce, Cynthia; McClymont, Juliet; Evans, Mary; Crompton, Robin H.; Francis Thackeray, J.

    2014-09-01

    Here we report on a Holocene inter-dune site close to Walvis Bay (Namibia) which contains exceptionally well-preserved children's footprints. The footprint surface is dated using Optically Stimulated Luminescence (OSL) methods to approximately 1.5 ka. These dates are compared to those obtained at nearby footprint sites and used to verify a model of diachronous footprint surfaces and also add to the archaeological data available for the communities that occupied these near-coastal areas during the Holocene. This model of diachronous footprint surfaces has implications for other soft-sediment footprint sites such as the 1.5 Ma old footprints at Ileret (Kenya). The distribution of both human and animal tracks, is consistent with the passage of small flock of small ungulates (probably sheep/goats) followed by a group of approximately 9 ± 2 individuals (children or young adults). Age estimates from the tracks suggest that some of the individuals may have been as young as five years old. Variation in track topology across this sedimentologically uniform surface is explained in terms of variations in gait and weight/stature of the individual print makers and is used to corroborate a model of footprint morphology developed at a nearby site. The significance of the site within the literature on human footprints lies in the quality of the track preservation, their topological variability despite a potentially uniform substrate, and the small size of the tracks, and therefore the inferred young age of the track-makers. The site provides an emotive insight into the life of the track-makers.

  10. Synergistic effects for the TiO2/RuO2/Pt photodissociation of water

    Energy Technology Data Exchange (ETDEWEB)

    Blondel, G; Harriman, A; Williams, D

    1983-07-01

    Compressed discs of naked TiO2 or TiO2 coated with a thin film of a noble metal (e.g. Pt) do not photodissociate water upon illumination with UV light, but small amounts of H2 are generated if the TiO2 has been reduced in a stream of H2 at 600 C. Discs prepared from mixtures of TiO2/RuO2 facilitate the UV photodissociation of water into H2 and O2 although the yields are very low. When a thin (about 9 nm) film of Pt is applied to the TiO2/RuO2 discs, the yields of H2 and O2 observed upon irradiation with UV light are improved drastically. 25 references.

  11. Theoretical treatment of photodissociation of water by time-dependent quantum mechanical methods

    International Nuclear Information System (INIS)

    Weide, K.

    1993-01-01

    An algorithm for wavepacket propagation, based on Kosloff's method of expansion of the time evolution operator in terms of Chebychev polynomials, and some details of its implementation are described. With the programs developed, quantum-mechanical calculations for up to three independent molecular coordinates are possible and feasible and therefore photodissociation of non-rotating triatomic molecules can be treated exactly. The angular degree of freedom here is handled by expansion in terms of free diatomic rotor states. The time-dependent wave packet picture is compared with the more traditional view of stationary wave functions, and both are used to interpret computational results where appropriate. Two-dimensional calculations have been performed to explain several experimental observations about water photodissociation. All calculations are based on ab initio potential energy surfaces, and it is explained in each case why it is reasonable to neglect the third degree of freedom. Many experimental results are reproduced quantitatively. (orig.) [de

  12. Photodissociation thresholds of OH produced from CH sub 3 OH in solid neon and argon

    CERN Document Server

    Cheng, B M; Lo, W J; Lee, Y P

    2001-01-01

    Photodissociation thresholds of OH from CH sub 3 OH in solid Ne and Ar were determined via photolysis of CH sub 3 OH/Ne and CH sub 3 OH/Ar (1/200) samples in situ at 4 K. The samples were irradiated with VUV synchrotron radiation after dispersion by a Seya-Namioka monochromator. The OH photo-product was detected by means of laser-induced fluorescence technique. The increase of fluorescent intensity of OH was monitored and recorded after the matrix sample was irradiated at different wavelengths for 3-5 min. Photodissociation threshold energies of 7.13+-0.02 eV (174.0+-0.5 nm) and 7.08+-0.04 eV (175.0+-1.0 nm) were measured for OH production of CH sub 3 OH in solid Ne and Ar, respectively.

  13. Effect of linear chirp on strong field photodissociation of H+2

    International Nuclear Information System (INIS)

    Prabhudesai, Vaibhav; Natan, Adi; Bruner, Barry; Silberberg, Yaron; Lev, Uri; Heber, Oded; Strasser, Daniel; Schwalm, Dirk; Zajfman, Daniel; Ben-Itzhak, Itzik

    2011-01-01

    We report the experimental findings of a systematic study of the effect of linear chirp on strong field photodissociation of H + 2 . For vibrational levels around or above the one photon crossing, the effect manifests itself in terms of a shift in the kinetic energy release (KER) peaks. The peaks shift up for negative chirp whereas they shift down for positive chirp. The measurements are carried out by varying two of the three laser pulse characteristics, energy, pulse peak intensity and linear chirp, while keeping the third constant. The shifts in the KER peaks are found to be intensity dependent for a given value of chirp. However, in the last two cases (i.e., fixed pulsed energy and fixed pulse peak intensity), they are found to be independent of the chirp magnitude. The results are understood on the basis of saturation of photodissociation probabilities for these levels.

  14. Effect of linear chirp on strong field photodissociation of H{sup +}{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Prabhudesai, Vaibhav; Natan, Adi; Bruner, Barry; Silberberg, Yaron; Lev, Uri; Heber, Oded; Strasser, Daniel; Schwalm, Dirk; Zajfman, Daniel [Weizmann Institute of Science, 76100 (Israel); Ben-Itzhak, Itzik [Kansas State University, Kansas (United States)

    2011-10-15

    We report the experimental findings of a systematic study of the effect of linear chirp on strong field photodissociation of H{sup +}{sub 2}. For vibrational levels around or above the one photon crossing, the effect manifests itself in terms of a shift in the kinetic energy release (KER) peaks. The peaks shift up for negative chirp whereas they shift down for positive chirp. The measurements are carried out by varying two of the three laser pulse characteristics, energy, pulse peak intensity and linear chirp, while keeping the third constant. The shifts in the KER peaks are found to be intensity dependent for a given value of chirp. However, in the last two cases (i.e., fixed pulsed energy and fixed pulse peak intensity), they are found to be independent of the chirp magnitude. The results are understood on the basis of saturation of photodissociation probabilities for these levels.

  15. Characteristic analysis of laser isotope separation process by two-step photodissociation method

    International Nuclear Information System (INIS)

    Okamoto, Tsuyoshi; Suzuki, Atsuyuki; Kiyose, Ryohei

    1981-01-01

    A large number of laser isotope separation experiments have been performed actively in many countries. In this paper, the selective two-step photodissociation method is chosen and simultaneous nonlinear differential equations that express the separation process are solved directly by using computer. Predicted separation factors are investigated in relation to the incident pulse energy and the concentration of desired molecules. Furthermore, the concept of separative work is used to evaluate the results of separation for this method. It is shown from an example of numerical calculation that a very large separation factor can be obtained if the concentration of desired molecules is lowered and two laser pulses to be closely synchronized are not always required in operation for the photodissociation of molecules. (author)

  16. Carbon footprint: a head-teaser

    International Nuclear Information System (INIS)

    Chandes, C.; Cahuzac, A.; Deniel, P.

    2011-01-01

    The author outlines the difficulties faced by industries to assess the impact of their activities on the environment, and more particularly their carbon footprint which is to be reduced, as well as greenhouse gas emissions. One of these difficulties for these companies is to choose among many methods and service providers to perform this carbon footprint assessment. Even if the result of this assessment could therefore be a matter of discussion, some companies may use this assessment as a marketing tool, whereas the ADEME notices that many requirements in terms of emission reduction actions are not met

  17. Footprint analysis during the growth period.

    Science.gov (United States)

    Volpon, J B

    1994-01-01

    Static footprints were obtained from 672 healthy white subjects ranging in age from newborn to 15 years. The length of the footprint was measured and the medial longitudinal arch was evaluated. The findings showed that the feet grew most rapidly up to 3 years of age. From age 3 onward, the feet maintained an almost constant growth rate, which was the same for both sexes until age 12 years, when girls' feet stopped growing, but boys' feet exhibited further growth. From birth up to 2 years of age, there was a higher incidence of flat feet. Rapid progression of plantar arch development was observed between 2 and 6 years of age.

  18. Redesigning Manufacturing Footprint from Dynamic Perspective

    DEFF Research Database (Denmark)

    Yang, Cheng; Farooq, Sami; Johansen, John

    2009-01-01

    footprint to address the constantly emerging new challenges by giving a holistic approach from dynamic perspective. Three Danish companies are presented. The way they developed their international manufacturing networks is analysed historically, and their redesigning of manufacturing footprint is expressed...... as how to re-assign portfolios of products and processes between specific plants within the same manufacturing network at one point in time. The strategic factors that have impact on such decisions are discussed and classified into two groups. Last, a holistic framework and a process model is presented...

  19. Photodissociation of OCS: deviations between theory and experiment, and the importance of higher order correlation effects.

    Science.gov (United States)

    Schmidt, J A; Olsen, J M H

    2014-11-14

    The photodissociation of carbonyl sulfide (OCS) was investigated theoretically in a series of studies by Schmidt and co-workers. Initial studies [J. A. Schmidt, M. S. Johnson, G. C. McBane, and R. Schinke, J. Chem. Phys. 136, 131101 (2012); J. A. Schmidt, M. S. Johnson, G. C. McBane, and R. Schinke, J. Chem. Phys. 137, 054313 (2012)] found photodissociation in the first UV-band to occur mainly by excitation of the 2(1)A' (A) excited state. However, in a later study [G. C. McBane, J. A. Schmidt, M. S. Johnson, and R. Schinke, J. Chem. Phys. 138, 094314 (2013)] it was found that a significant fraction of photodissociation must occur by excitation of 1(1)A″ (B) excited state to explain the product angular distribution. The branching between excitation of the A and B excited states is determined by the magnitude of the transition dipole moment vectors in the Franck-Condon region. This study examines the sensitivity of these quantities to changes in the employed electronic structure methodology. This study benchmarks the methodology employed in previous studies against highly correlated electronic structure methods (CC3 and MRAQCC) and provide evidence in support of the picture of the OCS photodissociation process presented in [G. C. McBane, J. A. Schmidt, M. S. Johnson, and R. Schinke, J. Chem. Phys. 138, 094314 (2013)] showing that excitation of A and B electronic states both contribute significantly to the first UV absorption band of OCS. In addition, this study presents evidence in support of the assertion that the A state potential energy surface employed in previous studies underestimates the energy at highly bent geometries (γ ∼ 70°) leading to overestimated rotational energy in the product CO.

  20. Photodissociation of OCS: Deviations between theory and experiment, and the importance of higher order correlation effects

    International Nuclear Information System (INIS)

    Schmidt, J. A.; Olsen, J. M. H.

    2014-01-01

    The photodissociation of carbonyl sulfide (OCS) was investigated theoretically in a series of studies by Schmidt and co-workers. Initial studies [J. A. Schmidt, M. S. Johnson, G. C. McBane, and R. Schinke, J. Chem. Phys. 136, 131101 (2012); J. A. Schmidt, M. S. Johnson, G. C. McBane, and R. Schinke, J. Chem. Phys. 137, 054313 (2012)] found photodissociation in the first UV-band to occur mainly by excitation of the 2 1 A ′ (A) excited state. However, in a later study [G. C. McBane, J. A. Schmidt, M. S. Johnson, and R. Schinke, J. Chem. Phys. 138, 094314 (2013)] it was found that a significant fraction of photodissociation must occur by excitation of 1 1 A ″ (B) excited state to explain the product angular distribution. The branching between excitation of the A and B excited states is determined by the magnitude of the transition dipole moment vectors in the Franck-Condon region. This study examines the sensitivity of these quantities to changes in the employed electronic structure methodology. This study benchmarks the methodology employed in previous studies against highly correlated electronic structure methods (CC3 and MRAQCC) and provide evidence in support of the picture of the OCS photodissociation process presented in [G. C. McBane, J. A. Schmidt, M. S. Johnson, and R. Schinke, J. Chem. Phys. 138, 094314 (2013)] showing that excitation of A and B electronic states both contribute significantly to the first UV absorption band of OCS. In addition, this study presents evidence in support of the assertion that the A state potential energy surface employed in previous studies underestimates the energy at highly bent geometries (γ ∼ 70°) leading to overestimated rotational energy in the product CO

  1. Photodissociation dynamics of 1-propanol and 2-propanol at 193.3 nm

    International Nuclear Information System (INIS)

    Zhou Weidong; Yuan Yan; Zhang Jingsong

    2003-01-01

    193.3-nm photodissociation dynamics of jet-cooled 1-propanol and 2-propanol and their partially deuterated variants are examined by using the high-n Rydberg-atom time-of-flight technique. Isotope labeling studies show that O-H bond fission is the primary H-atom production channel in the ultraviolet photodissociation of both 1-propanol and 2-propanol. Center-of-mass (c.m.) product translational energy release of the RO-H dissociation channel is large, with T >=0.78 for H+1-propoxy (n-propoxy) and 0.79 for H+2-propoxy (isoproxy). Maximum c.m. translational energy release yields an upper limit of the O-H bond dissociation energy: 433±2 kJ/mol in 1-propanol and 435±2 kJ/mol in 2-propanol. H-atom product angular distribution is anisotropic (with β≅-0.79 for 1-propanol and -0.77 for 2-propanol), suggesting an electronic transition moment perpendicular to the H-O-C plane and a short excited-state dissociation lifetime (less than a rotational period). Information about photodissociation dynamics and bond energies of the partially deuterated propanols are also obtained. The 193.3-nm photodissociation dynamics of 1-propanol and 2-propanol are nearly identical to each other and are similar to those of methanol and ethanol. This indicates a common RO-H dissociation mechanism: after the n O →σ * (O-H)/3s excitation localized on the H-O-C moiety, the H atom is ejected promptly in the H-O-C plane in a time scale shorter than a rotational period of the parent molecule, and it dissociates along the O-H coordinate on the repulsive excited-state potential-energy surface with a large translational energy release

  2. Resource Footprints are Good Proxies of Environmental Damage

    NARCIS (Netherlands)

    Steinmann, Z.J.N.; Schipper, A.M.; Hauck, M.; Giljum, S.; Wernet, G.; Huijbregts, M.A.J.

    2017-01-01

    Environmental footprints are increasingly used to quantify and compare environmental impacts of for example products, technologies, households, or nations. This has resulted in a multitude of footprint indicators, ranging from relatively simple measures of resource use (water, energy, materials) to

  3. Five propositions to harmonize environmental footprints of food and beverages

    NARCIS (Netherlands)

    Ponsioen, Tommie; Werf, Van Der H.M.G.

    2017-01-01

    Several attempts have been made to harmonize guidelines for environmental footprints of food and beverages. For example, the food Sustainable Consumption and Production Roundtable, the Leap partnership, and the Environmental Footprint project, in particular within the Cattle Model Working Group.

  4. Plant surface wax affects parasitoid's response to host footprints

    Science.gov (United States)

    Rostás, Michael; Ruf, Daniel; Zabka, Vanessa; Hildebrandt, Ulrich

    2008-10-01

    The plant surface is the substrate upon which herbivorous insects and natural enemies meet and thus represents the stage for interactions between the three trophic levels. Plant surfaces are covered by an epicuticular wax layer which is highly variable depending on species, cultivar or plant part. Differences in wax chemistry may modulate ecological interactions. We explored whether caterpillars of Spodoptera frugiperda, when walking over a plant surface, leave a chemical trail (kairomones) that can be detected by the parasitoid Cotesia marginiventris. Chemistry and micromorphology of cuticular waxes of two barley eceriferum wax mutants ( cer-za.126, cer-yp.949) and wild-type cv. Bonus (wt) were assessed. The plants were then used to investigate potential surface effects on the detectability of caterpillar kairomones. Here we provide evidence that C. marginiventris responds to chemical footprints of its host. Parasitoids were able to detect the kairomone on wild-type plants and on both cer mutants but the response to cer-yp.949 (reduced wax, high aldehyde fraction) was less pronounced. Experiments with caterpillar-treated wt and mutant leaves offered simultaneously, confirmed this observation: no difference in wasp response was found when wt was tested against cer-za.126 (reduced wax, wt-like chemical composition) but wt was significantly more attractive than cer-yp.949. This demonstrates for the first time that the wax layer can modulate the detectability of host kairomones.

  5. Classical photodissociation dynamics with Bohr quantization: Application to the fragmentation of a van der Waals cluster

    International Nuclear Information System (INIS)

    Arbelo-González, W.; Bonnet, L.; Larrégaray, P.; Rayez, J.-C.; Rubayo-Soneira, J.

    2012-01-01

    Graphical abstract: A recent classical description of photodissociation dynamics in a quantum spirit is applied for the first time to a realistic process, the fragmentation of NeBr 2 . Highlights: ► The photo-dissociation of NeBr 2 is studied by means of two approaches. ► The first is the standard classical one with Gaussian binning. ► The second is a new method applied for the first time to a realistic system. ► The new method leads to exactly the same results as the standard one. ► However, it requires about 10 times less trajectories in the present case. - Abstract: The recent classical dynamical approach of photodissociations with Bohr quantization [L. Bonnet, J. Chem. Phys. 133 (2010) 174108] is applied for the first time to a realistic process, the photofragmentation of the van der Waals cluster NeBr 2 . We illustrate the fact that this approach, formally equivalent to the standard one, may be numerically much more efficient.

  6. Quantum chemical molecular dynamical investigation of alkyl nitrite photo-dissociated on copper surfaces

    International Nuclear Information System (INIS)

    Wang Xiaojing; Wang Wei; Han Peilin; Kubo, Momoji; Miyamoto, Akira

    2008-01-01

    An accelerated quantum chemical molecular dynamical code 'Colors-Excite' was used to investigate the photolysis of alkyl nitrites series, RONO (R=CH 3 and C(CH 3 ) 3 ) on copper surfaces. Our calculations showed that the photo-dissociated processes are associated with the alkyl substituents of RONO when adsorbed on copper surfaces. For R=CH 3 , a two-step photolysis reaction occurred, yielding diverse intermediate products including RO radical, NO, and HNO, consistent with those reported in gas phase. While for R=C(CH 3 ) 3 , only one-step photolysis reaction occurred and gave intermediate products of RO radical and NO. Consequently, pure RO species were achieved to adsorb on metal surfaces by removing the NO species in photolysis reaction. The detailed photo-dissociated behaviors of RONO on copper surfaces with different alkyl substituents which are uncovered by the present simulation can be extended to explain the diverse dissociative mechanism experimentally observed. The quantum chemical molecular dynamical code 'Colors-Excite' is proved to be highly applicable to the photo-dissociations on metal surfaces

  7. Photodissociation from a manifold of rovibrational states and free-free absorption by a diatomic molecule

    International Nuclear Information System (INIS)

    Lebedev, V S; Presnyakov, L P

    2002-01-01

    An analytical approach for the description of photoabsorption by a gas or plasma medium containing atomic and molecular components in thermodynamic equilibrium is developed. Continuous absorption of radiation is due to the photodissociation of a diatomic molecule from a manifold of excited rovibrational states and free-free transitions between the two electronic terms of a quasimolecule temporarily formed during a collision of atomic particles. The formulae are obtained for individual photodissociation cross sections from a given rovibrational state and for the Boltzmann-averaged cross section. Particular attention is paid to the derivation of a general analytical expression for the total absorption coefficient including the integral contribution of bound-free and free-free radiative transitions. The consideration is based on the theory of nonadiabatic transitions combined with the approximation of a quasicontinuum for rovibrational states. The theory is applied to the investigation of photoabsorption by the H 2 + ion in the IR, visible and UV spectral regions. It is shown that our results are in good agreement with available ab initio quantal calculations of photodissociation cross sections and with semiclassical calculations of absorption coefficients. Special attention is paid to the investigation of the relative contributions of the H 2 + and H - ions to the total absorption in a wide range of wavelengths and temperatures

  8. The carbon footprint of exported Brazilian yellow melon

    NARCIS (Netherlands)

    Brito de Figueirêdo, M.C.; Kroeze, C.; Potting, J.; Silva Barros, da V.; Sousa de Aragão, A.; Sonsol Gondim, R.; Boer, de I.J.M.

    2013-01-01

    The carbon footprint of food has become important for producers worldwide as consumers and retail companies increasingly base their purchase decisions on carbon footprint labels. In this context, our objectives is to assess the carbon footprint (CF) of Brazilian yellow melon exported from the Low

  9. The water footprint of food aid

    NARCIS (Netherlands)

    Jackson, Nicole; Konar, Megan; Hoekstra, Arjen Ysbert

    2015-01-01

    Food aid is a critical component of the global food system, particularly when emergency situations arise. For the first time, we evaluate the water footprint of food aid. To do this, we draw on food aid data from theWorld Food Programme and virtual water content estimates from WaterStat. We find

  10. Water neutral: reducing and ofsetting water footprints

    NARCIS (Netherlands)

    Hoekstra, Arjen Ysbert

    2008-01-01

    During the past few years the concept of the ‘water footprint’ has started to receive recognition within governments, non-governmental organizations, businesses and media as a useful indicator of water use. The increased interest in the water-footprint concept has prompted the question about what

  11. Corporate Carbon Footprint Arla Foods amba

    DEFF Research Database (Denmark)

    Birkved, Morten; Poulsen, Jan; Shonfield, Peter

    2009-01-01

    to affect consumers’ purchasing decisions Recognising the potentially important impact of climate change on its business, as well as its wider social responsibility to effectively manage its GHG emissions, Arla Foods has commissioned PE North West Europe to carry out a corporate carbon footprint analysis...

  12. On Touristic Ecological Footprint of Macau

    Institute of Scientific and Technical Information of China (English)

    Zhang Meng; Yang Yu

    2012-01-01

    Despite its tiny territory, Macau boasts a large volume of tourist activities, which serves as the pillar of its economy. En- vironment and natural resources are the cornerstone of tourism, but are also subject to the negative impact of tourism. Based on the theory and methodology of ecological footprint analysis, this paper calculated the touristic ecological footprint and deficit of Macau in 2009, in an effort to bring to light the current status of excessive consumption of resources by tourism. As the findings show, the non-h'ansferable touristic ecological footprint and touristic ecologi- cal deficit of Macau in 2009 are respectively 18 300.891 gha and 12 737.584 gha, and the former is 3.29 times as large as the tour- istic ecological carrying capacity. Touristic ecological footprint of Macau is highly efficient in economic sense but currently tourism is developing in an unsustainable manner, so appropriate initiatives are in need to strike a balance between tourism development and resource conservation and to promote the sustainability of tourism industry of Macau.

  13. The water footprint of tourism in Spain

    NARCIS (Netherlands)

    Cazcarro, I.; Hoekstra, Arjen Ysbert; Sánchez Chóliz, J.

    2014-01-01

    This study complements the water footprint (WF) estimations for Spain, incorporating insights of the process analysis and input–output (IO) analysis. We evaluate the virtual (both blue and green consumed) water trade of agricultural and industrial products, but also of services, especially through

  14. ECOLOGICAL FOOTPRINT ANALYSIS OF CANNED SWEET CORN

    Directory of Open Access Journals (Sweden)

    Phairat Usubharatana

    2016-07-01

    Full Text Available There has been a notable increase in both consumer knowledge and awareness regarding the ecological benefits of green products and services. Manufacturers now pay more attention to green, environmentally friendly production processes. Two significant tools that can facilitate such a goal are life cycle assessment (LCA and ecological footprint (EF. This study aimed to analyse and determine the damage to the environment, focusing on the canned fruit and vegetable processing. Canned sweet corn (340 g was selected for the case study. All inputs and outputs associated with the product system boundary were collected through field surveys. The acquired inventory was then analysed and evaluated using both LCA and EF methodology. The results were converted into an area of biologically productive land and presented as global hectares (gha. The ecological footprint of one can of sweet corn was calculated as 6.51E-04 gha. The three factors with the highest impact on ecological footprint value were the corn kernels used in the process, the packaging and steam, equivalent to 2.93E-04 gha, 1.19E-04 gha and 1.17E-04 gha respectively. To promote the sustainable development, the company should develop new technology or utilize better management techniques to reduce the ecological footprint of canned food production.

  15. Spatially and temporally explicit water footprint accounting

    NARCIS (Netherlands)

    Mekonnen, Mesfin

    2011-01-01

    The earth’s freshwater resources are subject to increasing pressure in the form of consumptive water use and pollution (Postel, 2000; WWAP, 2003, 2006, 2009). Quantitative assessment of the green, blue and grey water footprint of global production and consumption can be regarded as a key in

  16. Synchrotron X-Ray Footprinting on Tour

    OpenAIRE

    Bohon, Jen; Ralston, Corie; D'Mello, Rhijuta; Gupta, Sayan; Chance, Mark R.

    2014-01-01

    Synchrotron X-ray footprinting resources were investigated at a variety of beamlines and synchrotron facilities to understand their potential for a mobile general user. Results indicate that viable resources exist at each synchrotron investigated such that a prospective user need only provide a simple flow apparatus and sample handling accessories to perform this technique.

  17. How to Calculate Your Institution's Nitrogen Footprint ...

    Science.gov (United States)

    The Nitrogen Footprint Tool (NFT) allows institutions to estimate and manage their nitrogen footprint, and EPA’s Sustainable and Healthy Communities program is supporting an effort to test and expand this approach at multiple colleges, universities and institutions across the US. The growing awareness of sustainability has prompted many institutions of higher education to assess and manage their environmental impact. Many universities have programs to decrease their carbon footprint, but carbon represents just one facet of an institution’s environmental impact. Nitrogen is also important because a university’s nitrogen loss to the environment contributes to smog, soil acidification, eutrophication, biodiversity loss, the enhanced greenhouse effect, stratospheric ozone depletion, and more. The attached data template and user’s manual was based on the first NFT created for a university (University of Virginia), and tested in 6 additional institutions (including University of New Hampshire, Brown University, Eastern Mennonite University, Colorado State University). The footprint includes nitrogen released to the environment due to: 1) food consumption; 2) food production, reported by specific food categories (vegetable products, seafood, dairy and eggs, meat); 3) research animals; 4) transportation, including fleet vehicles and commuter vehicles; 5) fertilizer application; and 6) utilities, separated into electricity and heating. The data template and

  18. Footprint Representation of Planetary Remote Sensing Data

    Science.gov (United States)

    Walter, S. H. G.; Gasselt, S. V.; Michael, G.; Neukum, G.

    The geometric outline of remote sensing image data, the so called footprint, can be represented as a number of coordinate tuples. These polygons are associated with according attribute information such as orbit name, ground- and image resolution, solar longitude and illumination conditions to generate a powerful base for classification of planetary experiment data. Speed, handling and extended capabilites are the reasons for using geodatabases to store and access these data types. Techniques for such a spatial database of footprint data are demonstrated using the Relational Database Management System (RDBMS) PostgreSQL, spatially enabled by the PostGIS extension. Exemplary, footprints of the HRSC and OMEGA instruments, both onboard ESA's Mars Express Orbiter, are generated and connected to attribute information. The aim is to provide high-resolution footprints of the OMEGA instrument to the science community for the first time and make them available for web-based mapping applications like the "Planetary Interactive GIS-on-the-Web Analyzable Database" (PIG- WAD), produced by the USGS. Map overlays with HRSC or other instruments like MOC and THEMIS (footprint maps are already available for these instruments and can be integrated into the database) allow on-the-fly intersection and comparison as well as extended statistics of the data. Footprint polygons are generated one by one using standard software provided by the instrument teams. Attribute data is calculated and stored together with the geometric information. In the case of HRSC, the coordinates of the footprints are already available in the VICAR label of each image file. Using the VICAR RTL and PostgreSQL's libpq C library they are loaded into the database using the Well-Known Text (WKT) notation by the Open Geospatial Consortium, Inc. (OGC). For the OMEGA instrument, image data is read using IDL routines developed and distributed by the OMEGA team. Image outlines are exported together with relevant attribute

  19. An atomic perspective of the photodissociation and geminate recombination of triiodide in condensed phases

    Energy Technology Data Exchange (ETDEWEB)

    Xian, Rui

    2016-11-15

    The thesis presents progress made towards a thorough understanding of the photodissociation and geminate recombination of triiodide anion (I{sub 3}{sup -}) in solution and solid state using novel time-resolved spectroscopic and structural methods that have matured in the past decade. An isolated I{sub 3}{sup -} has only three degrees of freedom, but in the condensed phase, the case of an open quantum system, its chemistry is transformed because other degrees of freedom from the surroundings (the bath) need to be fully taken into account. This system is a textbook example for understanding dissociation and recombination processes in condensed phases, but unresolved issues about the reaction pathways remain. To probe the issues, firstly, mid-UV pulse shaper-based closed-loop adaptive control as well as open-loop power and chirp control schemes were used in conjunction with single-color pump-probe detection of the yield of the photoproduct diiodide (I{sub 2}{sup -.}) to study the above reaction in ethanol solution. The experiments revealed a strong pump-chirp dependence of the I{sub 2}{sup -.}-yield (as much as 40% change). Subsequently, two possible mechanisms involving additional reaction channels were postulated in order to explain such effect. Secondly, pump-supercontinuum-probe spectroscopy and ultrafast electron diffraction were performed separately on solid state triiodide compound n-(C{sub 4}H{sub 9}){sub 4}NI{sub 3} (TBAT). This system was chosen to provide a well-defined lattice for the bath and to avail atomic resolution of the condensed phase reaction dynamics. In the optical experiment, coherent oscillations were observed within a probe delay of 1 ps that bear strong resemblance to the stretching modes of ground-state I{sub 3}{sup -} and I{sub 2}{sup -.} fragment, which makes it the first to reliably distinguish the two species in a single measurement. In addition, the spectroscopic signature of a novel intermediate, the tetraiodide anion (I{sub 4}{sup

  20. An atomic perspective of the photodissociation and geminate recombination of triiodide in condensed phases

    International Nuclear Information System (INIS)

    Xian, Rui

    2016-11-01

    The thesis presents progress made towards a thorough understanding of the photodissociation and geminate recombination of triiodide anion (I_3"-) in solution and solid state using novel time-resolved spectroscopic and structural methods that have matured in the past decade. An isolated I_3"- has only three degrees of freedom, but in the condensed phase, the case of an open quantum system, its chemistry is transformed because other degrees of freedom from the surroundings (the bath) need to be fully taken into account. This system is a textbook example for understanding dissociation and recombination processes in condensed phases, but unresolved issues about the reaction pathways remain. To probe the issues, firstly, mid-UV pulse shaper-based closed-loop adaptive control as well as open-loop power and chirp control schemes were used in conjunction with single-color pump-probe detection of the yield of the photoproduct diiodide (I_2"-".) to study the above reaction in ethanol solution. The experiments revealed a strong pump-chirp dependence of the I_2"-".-yield (as much as 40% change). Subsequently, two possible mechanisms involving additional reaction channels were postulated in order to explain such effect. Secondly, pump-supercontinuum-probe spectroscopy and ultrafast electron diffraction were performed separately on solid state triiodide compound n-(C_4H_9)_4NI_3 (TBAT). This system was chosen to provide a well-defined lattice for the bath and to avail atomic resolution of the condensed phase reaction dynamics. In the optical experiment, coherent oscillations were observed within a probe delay of 1 ps that bear strong resemblance to the stretching modes of ground-state I_3"- and I_2"-". fragment, which makes it the first to reliably distinguish the two species in a single measurement. In addition, the spectroscopic signature of a novel intermediate, the tetraiodide anion (I_4"-".), was identified and its origin is attributed to intermolecular interaction of the

  1. DC slice ion imaging study of atomic orbital orientation and alignment in photodissociation

    Science.gov (United States)

    Lee, Suk Kyoung

    A complete study of atomic photofragment polarization has been achieved by using DC slice imaging, a recently developed approach directly providing the central slice of the full 3D product distribution without any mathematical transformation. In this dissertation, the quantum mechanical treatment adapted for the sliced images has been derived to extract the angular momentum polarization anisotropy parameters for any recoil speeds. The important photodissociation dynamics of small polyatomic molecules has been presented based on the thorough interpretation of the observed orientation and alignment. The first demonstration of DC slice imaging of orbital polarization was a study of the 193 nm photodissociation of ethylene sulfide, followed by detailed investigation in ozone and OCS. In ozone, the speed-dependent orientation was measured for O(1D2) atom produced from photodissociation in the 248--285 nm region. The results show negligible orbital orientation following dissociation by circularly polarized light but strong recoil speed-dependent orientation following photolysis by linearly polarized light at all wavelengths studied. The origin of this polarization is ascribed to nonadiabatic transitions at avoided crossings and at long range. The atomic orbital alignment and orientation, including the higher order moments (K = 3, 4), has been carried out for the photodissociation of OCS at 193 nm. The observed speed-dependent beta and polarization parameters of S(1D2) atom support the interpretation that there are two main dissociation processes: a simultaneous two-surface excitation and the initial single-surface excitation followed by the nonadiabatic crossing to the ground state. The angle- and speed-dependent density matrix can be constructed containing the higher order contributions for circularly-polarized dissociation light. It was shown in one case that the higher order contributions should not be overlooked for an accurate picture of the dissociation dynamics in

  2. Carbon footprint of cartons in Europe - Carbon Footprint methodology and biogenic carbon sequestration

    Energy Technology Data Exchange (ETDEWEB)

    Eriksson, Elin; Karlsson, Per-Erik; Hallberg, Lisa; Jelse, Kristian

    2010-05-15

    A methodology for carbon sequestration in forests used for carton production has been developed and applied. The average Carbon Footprint of converted cartons sold in Europe has been calculated and summarised. A methodology for a EU27 scenario based assessment of end of life treatment has been developed and applied. The average Carbon Footprint represents the total Greenhouse Gas emissions from one average tonne of virgin based fibres and recycled fibres produced, converted and printed in Europe

  3. Complex chemistry

    International Nuclear Information System (INIS)

    Kim, Bong Gon; Kim, Jae Sang; Kim, Jin Eun; Lee, Boo Yeon

    2006-06-01

    This book introduces complex chemistry with ten chapters, which include development of complex chemistry on history coordination theory and Warner's coordination theory and new development of complex chemistry, nomenclature on complex with conception and define, chemical formula on coordination compound, symbol of stereochemistry, stereo structure and isomerism, electron structure and bond theory on complex, structure of complex like NMR and XAFS, balance and reaction on solution, an organo-metallic chemistry, biology inorganic chemistry, material chemistry of complex, design of complex and calculation chemistry.

  4. Mathematical Chemistry

    OpenAIRE

    Trinajstić, Nenad; Gutman, Ivan

    2002-01-01

    A brief description is given of the historical development of mathematics and chemistry. A path leading to the meeting of these two sciences is described. An attempt is made to define mathematical chemistry, and journals containing the term mathematical chemistry in their titles are noted. In conclusion, the statement is made that although chemistry is an experimental science aimed at preparing new compounds and materials, mathematics is very useful in chemistry, among other things, to produc...

  5. Hyakutake, Hale-Bopp and the chemistry of comets

    International Nuclear Information System (INIS)

    Bachiller, R.; Planesas, P.

    1997-01-01

    Comets can be regarded as messengers from the primitive solar system which can provide precious pieces of information on the composition of the protosolar nebula. Physical and chemical phenomena within comets (shock waves, photodissociation caused by solar radiation, some endothermic chemical reactions, etc) are of the highest interest and cannot be reproduced at terrestrial laboratories in many cases. The passage of Hyakutake in 1996 and that of Hale-Bopp in 1997 are allowing remarkable progress in the understanding of the physico-chemistry of comets. Observations of such comets can be crucial in the study of the origin of life on Earth. (Author)

  6. Age, Sex and Stature Estimation from Footprint Dimensions

    Directory of Open Access Journals (Sweden)

    Paurbhi Singh

    2017-04-01

    Full Text Available Objectives: The present study was carried out to evaluate the utility and reliability of footprint dimensions in age, sex and stature determination in the North Indian population. Materials and Methods: This study was carried out using a sample of 400 people (146 female and 254 male aged 10-65 years in Uttar Pradesh, North Western state of India. Footprints of both feet were taken bilaterally, and thus a total of 800 prints were obtained. A cluster of 7 measurements were taken carefully with the help of a scientific scale ruler. Five measurements were length dimensions from the most anterior part of the toe (T1–T5 to the mid rear heel point and two were breadth dimensions from both left and right footprints: breadth at ball (BBAL, breadth at heel (BHEL and 2 indexes: heel-ball Index (HBI and footprint index (FPI. All data were analyzed statistically using Student’s t-test, regression coefficient and Pearson’s correlation for the estimation of sex on the basis of footprint dimensions. Results: The T1 in left footprints was greater than right footprints in males, while T1 and BBAL were both found to be greater in left footprints than right footprints in females. All the seven foot dimensions were higher in males than females. Conclusion: There were statistically significant differences observed in all footprint dimensions between the male and female footprints except LFPI, LHBI, and RHBI.

  7. Does footprint depth correlate with foot motion and pressure?

    Science.gov (United States)

    Bates, K T; Savage, R; Pataky, T C; Morse, S A; Webster, E; Falkingham, P L; Ren, L; Qian, Z; Collins, D; Bennett, M R; McClymont, J; Crompton, R H

    2013-06-06

    Footprints are the most direct source of evidence about locomotor biomechanics in extinct vertebrates. One of the principal suppositions underpinning biomechanical inferences is that footprint geometry correlates with dynamic foot pressure, which, in turn, is linked with overall limb motion of the trackmaker. In this study, we perform the first quantitative test of this long-standing assumption, using topological statistical analysis of plantar pressures and experimental and computer-simulated footprints. In computer-simulated footprints, the relative distribution of depth differed from the distribution of both peak and pressure impulse in all simulations. Analysis of footprint samples with common loading inputs and similar depths reveals that only shallow footprints lack significant topological differences between depth and pressure distributions. Topological comparison of plantar pressures and experimental beach footprints demonstrates that geometry is highly dependent on overall print depth; deeper footprints are characterized by greater relative forefoot, and particularly toe, depth than shallow footprints. The highlighted difference between 'shallow' and 'deep' footprints clearly emphasizes the need to understand variation in foot mechanics across different degrees of substrate compliance. Overall, our results indicate that extreme caution is required when applying the 'depth equals pressure' paradigm to hominin footprints, and by extension, those of other extant and extinct tetrapods.

  8. Footprint parameters as a measure of arch height.

    Science.gov (United States)

    Hawes, M R; Nachbauer, W; Sovak, D; Nigg, B M

    1992-01-01

    The human foot has frequently been categorized into arch height groups based upon analysis of footprint parameters. This study investigates the relationship between directly measured arch height and many of the footprint parameters that have been assumed to represent arch height. A total of 115 male subjects were measured and footprint parameters were calculated from digitized outlines. Correlation and regression analyses were used to determine the relationship between footprint measures and arch height. It may be concluded from the results that footprint parameters proposed in the literature (arch angle, footprint index, and arch index) and two further parameters suggested in this study (arch length index and truncated arch index) are invalid as a basis for prediction or categorization of arch height. The categorization of the human foot according to the footprint measures evaluated in this paper represent no more than indices and angles of the plantar surface of the foot itself.

  9. Taiwan’s Ecological Footprint (1994–2011

    Directory of Open Access Journals (Sweden)

    Yung-Jaan Lee

    2014-09-01

    Full Text Available According to the 2011 edition of the National Footprint Accounts (NFA published by the Global Footprint Network (GFN, humankind consumed the resources and services of 1.5 planets in 2008; the corresponding number in 1961 was 0.7 planets. North Americans have an ecological footprint of 8.7 global hectares per person whereas Africans have a footprint of only 1.4 global hectares per person. The global mean biological capacity is only 1.8 global hectares per person so human beings are overshooting ecological resources. The ecological footprint measures the resources that are consumed by humans from the biosphere, and serves as an index of the sustainability of development. The NFA includes the ecological footprints of over 200 countries and regions, but not Taiwan. Hence, Taiwan must establish and update its own ecological footprint databases. Ecological footprint is one indicator of the sustainability of development, and can be compared across nations. This study extends previous studies by analyzing Taiwan’s ecological footprint from 2008–2011. With reference to the ecological footprint accounts of the Global Footprint Network and the Taiwan’s ecological footprint analysis for 1997–2007, this study presents Taiwan’s ecological footprint from 2008–2011. Most of the data that are used herein are taken from the Food and Agriculture Organization, the International Energy Agency, Taiwan’s Council of Agriculture and Taiwan’s National Development Council. The results thus obtained reveal that Taiwan’s ecological footprint from 2008–2011 exceeded that from 1997–2007. To respond to this trend toward un-sustainable development and to help Taiwan move toward sustainability, carbon reduction and energy saving policies should be implemented to effectively manage Taiwan’s ecological resources.

  10. Carbon footprint estimation of municipal water cycle

    Science.gov (United States)

    Bakhshi, Ali A.

    2009-11-01

    This research investigates the embodied energy associated with water use. A geographic information system (GIS) was tested using data from Loudoun County, Virginia. The objective of this study is to estimate the embodied energy and carbon emission levels associated with water service at a geographical location and to improve for sustainability planning. Factors that affect the carbon footprint were investigated and the use of a GIS based model as a sustainability planning framework was evaluated. The carbon footprint metric is a useful tool for prediction and measurement of a system's sustainable performance over its expected life cycle. Two metrics were calculated: tons of carbon dioxide per year to represent the contribution to global warming and watt-hrs per gallon to show the embodied energy associated with water consumption. The water delivery to the building, removal of wastewater from the building and associated treatment of water and wastewater create a sizable carbon footprint; often the energy attributed to this water service is the greatest end use of electrical energy. The embodied energy in water depends on topographical characteristics of the area's local water supply, the efficiency of the treatment systems, and the efficiency of the pumping stations. The questions answered by this research are: What is the impact of demand side sustainable water practices on the embodied energy as represented by a comprehensive carbon footprint? What are the major energy consuming elements attributed to the system? What is a viable and visually identifiable tool to estimate the carbon footprint attributed to those Greenhouse Gas (GHG) producing elements? What is the embodied energy and emission associated with water use delivered to a building? Benefits to be derived from a standardized GIS applied carbon footprint estimation approach include: (1) Improved environmental and economic information for the developers, water and wastewater processing and municipal

  11. Tracking the global footprint of fisheries

    Science.gov (United States)

    Kroodsma, David A.; Mayorga, Juan; Hochberg, Timothy; Miller, Nathan A.; Boerder, Kristina; Ferretti, Francesco; Wilson, Alex; Bergman, Bjorn; White, Timothy D.; Block, Barbara A.; Woods, Paul; Sullivan, Brian; Costello, Christopher; Worm, Boris

    2018-02-01

    Although fishing is one of the most widespread activities by which humans harvest natural resources, its global footprint is poorly understood and has never been directly quantified. We processed 22 billion automatic identification system messages and tracked >70,000 industrial fishing vessels from 2012 to 2016, creating a global dynamic footprint of fishing effort with spatial and temporal resolution two to three orders of magnitude higher than for previous data sets. Our data show that industrial fishing occurs in >55% of ocean area and has a spatial extent more than four times that of agriculture. We find that global patterns of fishing have surprisingly low sensitivity to short-term economic and environmental variation and a strong response to cultural and political events such as holidays and closures.

  12. Human Decisions: Nitrogen Footprints and Environmental Effects

    Science.gov (United States)

    Leach, A. M.; Bleeker, A.; Galloway, J. N.; Erisman, J.

    2012-12-01

    Human consumption choices are responsible for growing losses of reactive nitrogen (Nr) to the environment. Once in the environment, Nr can cause a cascade of negative impacts such as smog, acid rain, coastal eutrophication, climate change, and biodiversity loss. Although all humans must consume nitrogen as protein, the food production process releases substantial Nr to the environment. This dilemma presents a challenge: how do we feed a growing population while reducing Nr? Although top-down strategies to reduce Nr losses (e.g., emissions controls) are necessary, the bottom-up strategies focusing on personal consumption patterns will be imperative to solve the nitrogen challenge. Understanding the effects of different personal choices on Nr losses and the environment is an important first step for this strategy. This paper will utilize information and results from the N-Calculator, a per capita nitrogen footprint model (www.N-Print.org), to analyze the impact of different food consumption patterns on a personal food nitrogen footprint and the environment. Scenarios will analyze the impact of the following dietary patterns on the average United States (28 kg Nr/cap/yr) food nitrogen footprint: 1) Consuming only the recommended protein as defined by the WHO and the USDA; 2) Reducing food waste by 50%; 3) Consuming a vegetarian diet; 4) Consuming a vegan diet; 5) Consuming a demitarian diet (replacing half of animal protein consumption with vegetable protein); 6) Substituting chicken (a more efficient animal protein) with beef (a less efficient animal protein); 7) Consuming sustainably-produced food; and 8) Using advanced wastewater treatment. Preliminary results suggest that widespread advanced wastewater treatment with nutrient removal technology and halving food waste would each reduce the US personal food nitrogen footprint by 13%. In addition, reducing protein consumption to the recommended levels would reduce the footprint by about 42%. Combining these measures

  13. AcquisitionFootprintAttenuationDrivenbySeismicAttributes

    Directory of Open Access Journals (Sweden)

    Cuellar-Urbano Mayra

    2014-04-01

    Full Text Available Acquisition footprint, one of the major problems that PEMEX faces in seismic imaging, is noise highly correlated to the geometric array of sources and receivers used for onshore and offshore seismic acquisitions. It prevails in spite of measures taken during acquisition and data processing. This pattern, throughout the image, is easily confused with geological features and misguides seismic attribute computation. In this work, we use seismic data from PEMEX Exploración y Producción to show the conditioning process for removing random and coherent noise using linear filters. Geometric attributes used in a workflow were computed for obtaining an acquisition footprint noise model and adaptively subtract it from the seismic data.

  14. Mapping the carbon footprint of EU regions

    Science.gov (United States)

    Ivanova, Diana; Vita, Gibran; Steen-Olsen, Kjartan; Stadler, Konstantin; Melo, Patricia C.; Wood, Richard; Hertwich, Edgar G.

    2017-05-01

    While the EU Commission has encouraged Member States to combine national and international climate change mitigation measures with subnational environmental policies, there has been little harmonized effort towards the quantification of embodied greenhouse gas (GHG) emissions from household consumption across European regions. This study develops an inventory of carbon footprints associated with household consumption for 177 regions in 27 EU countries, thus, making a key contribution for the incorporation of consumption-based accounting into local decision-making. Footprint calculations are based on consumer expenditure surveys and environmental and trade detail from the EXIOBASE 2.3 multiregional input-output database describing the world economy in 2007 at the detail of 43 countries, 5 rest-of-the-world regions and 200 product sectors. Our analysis highlights the spatial heterogeneity of embodied GHG emissions within multiregional countries with subnational ranges varying widely between 0.6 and 6.5 tCO2e/cap. The significant differences in regional contribution in terms of total and per capita emissions suggest notable differences with regards to climate change responsibility. The study further provides a breakdown of regional emissions by consumption categories (e.g. housing, mobility, food). In addition, our region-level study evaluates driving forces of carbon footprints through a set of socio-economic, geographic and technical factors. Income is singled out as the most important driver for a region’s carbon footprint, although its explanatory power varies significantly across consumption domains. Additional factors that stand out as important on the regional level include household size, urban-rural typology, level of education, expenditure patterns, temperature, resource availability and carbon intensity of the electricity mix. The lack of cross-national region-level studies has so far prevented analysts from drawing broader policy conclusions that hold

  15. Conceptual basis for the european sustainability footprint

    OpenAIRE

    PELLETIER NATHANIEL; MAAS Rob; GORALCZYK MALGORZATA; WOLF Marc-Andree

    2012-01-01

    Sustainability is central to the policy objectives of the European Commission (EC), but a widely accepted integrated sustainability assessment framework in support of policy analysis and development is currently lacking. Here, we describe the conceptual basis for the proposed European Sustainability Footprint (ESF) - an integrated sustainability assessment framework for establishing a baseline and tracking trends with respect to the sustainability of European production and consumption. This ...

  16. Do parents leave a smaller carbon footprint?

    DEFF Research Database (Denmark)

    Nordström, Leif Jonas; Shogren, Jason F.; Thunström, Linda

    Do parents leave a smaller carbon footprint? While becoming a parent is transformational as one focuses more on the future, the time constraints are more binding right now. Using a unique data set that allows us to compare CO2 emissions from Swedish two-adult households with and without children......, we find becoming a Swedish parent causes a person to leave a larger carbon ootprint—due to changes in transportation patterns and food consumption choices....

  17. Chemistry Notes

    Science.gov (United States)

    School Science Review, 1976

    1976-01-01

    Described are eight chemistry experiments and demonstrations applicable to introductory chemistry courses. Activities include: measure of lattice enthalpy, Le Chatelier's principle, decarboxylation of soap, use of pocket calculators in pH measurement, and making nylon. (SL)

  18. Chemistry Dashboard

    Science.gov (United States)

    The Chemistry Dashboard is part of a suite of dashboards developed by EPA to help evaluate the safety of chemicals. The Chemistry Dashboard provides access to a variety of information on over 700,000 chemicals currently in use.

  19. Experimentally generated footprints in sand: Analysis and consequences for the interpretation of fossil and forensic footprints.

    Science.gov (United States)

    D'Août, Kristiaan; Meert, L; Van Gheluwe, B; De Clercq, D; Aerts, P

    2010-04-01

    Fossilized footprints contain information about the dynamics of gait, but their interpretation is difficult, as they are the combined result of foot anatomy, gait dynamics, and substrate properties. We explore how footprints are generated in modern humans. Sixteen healthy subjects walked on a solid surface and in a layer of fine-grained sand. In each condition, 3D kinematics of the leg and foot were analyzed for three trials at preferred speed, using an infrared camera system. Additionally, calibrated plantar pressures were recorded. After each trial in sand, the depth of the imprint was measured under specific sites. When walking in sand, subjects showed greater toe clearance during swing and a 7 degrees higher knee yield during stance. Maximal pressure was the most influential factor for footprint depth under the heel. For other foot zones, a combination of factors correlates with imprint depth, with pressure impulse (the pressure-time integral) gaining importance distally, at the metatarsal heads and the hallux. We conclude that footprint topology cannot be related to a single variable, but that different zones of the footprint reflect different aspects of the kinesiology of walking. Therefore, an integrated approach, combining anatomical, kinesiological, and substrate-mechanical insights, is necessary for a correct interpretation. (c) 2009 Wiley-Liss, Inc.

  20. Water Footprints and Sustainable Water Allocation

    Directory of Open Access Journals (Sweden)

    Arjen Y. Hoekstra

    2015-12-01

    Full Text Available Water Footprint Assessment (WFA is a quickly growing research field. This Special Issue contains a selection of papers advancing the field or showing innovative applications. The first seven papers are geographic WFA studies, from an urban to a continental scale; the next five papers have a global scope; the final five papers focus on water sustainability from the business point of view. The collection of papers shows that the historical picture of a town relying on its hinterland for its supply of water and food is no longer true: the water footprint of urban consumers is global. It has become clear that wise water governance is no longer the exclusive domain of government, even though water is and will remain a public resource with government in a primary role. With most water being used for producing our food and other consumer goods, and with product supply chains becoming increasingly complex and global, there is a growing awareness that consumers, companies and investors also have a key role. The interest in sustainable water use grows quickly, in both civil society and business communities, but the poor state of transparency of companies regarding their direct and indirect water use implies that there is still a long way to go before we can expect that companies effectively contribute to making water footprints more sustainable at a relevant scale.

  1. Photodissociation of dibromoethanes at 248 nm: an ignored channel of Br2 elimination.

    Science.gov (United States)

    Lee, Hsin-Lung; Lee, Ping-Chen; Tsai, Po-Yu; Lin, King-Chuen; Kuo, H H; Chen, P H; Chang, A H H

    2009-05-14

    Br(2) molecular elimination is probed in the photodissociation of 1,1- and 1,2-C(2)H(4)Br(2) isomeric forms at 248 nm by using cavity ring-down absorption spectroscopy. Their photodissociation processes differ markedly from each other. The quantum yield of the Br(2) fragment in 1,2-dibromoethane is 0.36+/-0.18, in contrast to a value of 0.05+/-0.03 in 1,1-dibromoethane. The vibrational population ratios of Br(2)(v=1)/Br(2)(v=0) are 0.8+/-0.1 and 0.5+/-0.2 for 1,2- and 1,1-dibromoethanes, respectively. The Br(2) yield densities are found to increase by a factor of 35% and 190% for 1,2- and 1,1-dibromoethanes within the same temperature increment. In the ab initio potential energy calculations, the transition state (TS) along the adiabatic ground state surface may correlate to the Br(2) products. The TS energy for 1,2-dibromoethane is well below the excitation energy at 483 kJ/mol, whereas that for 1,1-dibromoethane is slightly above. Such a small TS energy barrier impedes the photodissociation of the ground state 1,1-dibromoethane such that the production yield of Br(2) may become relatively low, but rise rapidly with the temperature. The TS structure shows a larger bond distance of Br-Br in 1,2-dibromoethane than that in 1,1-dibromoethane. That explains why the former isomer may result in hotter vibrational population of the Br(2) fragments.

  2. Combinatorial chemistry

    DEFF Research Database (Denmark)

    Nielsen, John

    1994-01-01

    An overview of combinatorial chemistry is presented. Combinatorial chemistry, sometimes referred to as `irrational drug design,' involves the generation of molecular diversity. The resulting chemical library is then screened for biologically active compounds.......An overview of combinatorial chemistry is presented. Combinatorial chemistry, sometimes referred to as `irrational drug design,' involves the generation of molecular diversity. The resulting chemical library is then screened for biologically active compounds....

  3. Aquatic Chemistry

    International Nuclear Information System (INIS)

    Kim, Dong Yeun; Kim, Oh Sik; Kim, Chang Guk; Park, Cheong Gil; Lee, Gwi Hyeon; Lee, Cheol Hui

    1987-07-01

    This book deals aquatic chemistry, which treats water and environment, chemical kinetics, chemical balance like dynamical characteristic, and thermodynamics, acid-base chemistry such as summary, definition, kinetics, and PH design for mixture of acid-base chemistry, complex chemistry with definition, and kinetics, precipitation and dissolution on summary, kinetics of precipitation and dissolution, and balance design oxidation and resolution with summary, balance of oxidation and resolution.

  4. Positronium chemistry

    CERN Document Server

    Green, James

    1964-01-01

    Positronium Chemistry focuses on the methodologies, reactions, processes, and transformations involved in positronium chemistry. The publication first offers information on positrons and positronium and experimental methods, including mesonic atoms, angular correlation measurements, annihilation spectra, and statistical errors in delayed coincidence measurements. The text then ponders on positrons in gases and solids. The manuscript takes a look at the theoretical chemistry of positronium and positronium chemistry in gases. Topics include quenching, annihilation spectrum, delayed coincidence

  5. Human footprint variation while performing load bearing tasks.

    Directory of Open Access Journals (Sweden)

    Cara M Wall-Scheffler

    Full Text Available Human footprint fossils have provided essential evidence about the evolution of human bipedalism as well as the social dynamics of the footprint makers, including estimates of speed, sex and group composition. Generally such estimates are made by comparing footprint evidence with modern controls; however, previous studies have not accounted for the variation in footprint dimensions coming from load bearing activities. It is likely that a portion of the hominins who created these fossil footprints were carrying a significant load, such as offspring or foraging loads, which caused variation in the footprint which could extend to variation in any estimations concerning the footprint's maker. To identify significant variation in footprints due to load-bearing tasks, we had participants (N = 30, 15 males and 15 females walk at a series of speeds carrying a 20kg pack on their back, side and front. Paint was applied to the bare feet of each participant to create footprints that were compared in terms of foot length, foot width and foot area. Female foot length and width increased during multiple loaded conditions. An appreciation of footprint variability associated with carrying loads adds an additional layer to our understanding of the behavior and morphology of extinct hominin populations.

  6. The relationship between plantar pressure and footprint shape.

    Science.gov (United States)

    Hatala, Kevin G; Dingwall, Heather L; Wunderlich, Roshna E; Richmond, Brian G

    2013-07-01

    Fossil footprints preserve the only direct evidence of the external foot morphologies and gaits of extinct hominin taxa. However, their interpretation requires an understanding of the complex interaction among foot anatomy, foot function, and soft sediment mechanics. We applied an experimental approach aimed at understanding how one measure of foot function, the distribution of plantar pressure, influences footprint topography. Thirty-eight habitually unshod and minimally shod Daasanach individuals (19 male, 19 female) walked across a pressure pad and produced footprints in sediment directly excavated from the geological layer that preserves 1.5 Ma fossil footprints at Ileret, Kenya. Calibrated pressure data were collected and three-dimensional models of all footprints were produced using photogrammetry. We found significant correlations (Spearman's rank, p plantar pressure distribution and relative footprint depths at ten anatomical regions across the foot. Furthermore, plantar pressure distributions followed a pattern similar to footprint topography, with areas of higher pressure tending to leave deeper impressions. This differs from the results of experimental studies performed in different types of sediment, supporting the hypothesis that sediment type influences the relationship between plantar pressure and footprint topography. Our results also lend support to previous interpretations that the shapes of the Ileret footprints preserve evidence of a medial transfer of plantar pressure during late stance phase, as seen in modern humans. However, the weakness of the correlations indicates that much of the variation in relative depths within footprints is not explained by pressure distributions under the foot when walking on firm ground, using the methods applied here. This warrants caution when interpreting the unique foot anatomies and foot functions of extinct hominins evidenced by their footprint structures. Further research is necessary to clarify how

  7. Isotope effects in photodissociation: Chemical reaction dynamics and implications for atmospheres

    DEFF Research Database (Denmark)

    Jørgensen, Solvejg; Grage, Mette Marie-Louise; Nyman, Gunnar

    2008-01-01

    obtaining the absorption and/or photodissociation cross section is a threefold challenge: computing the electronic potential energy surfaces, interpolating the potentials, and finding the cross section either by time-dependent or time-independent methods. We review electronic structure methods used...... for computing accurate potential energy surfaces for the electronic ground and accessible excited state as well as coupling between them (electronic transition dipole moments and diabatic coupling). Methods used for interpolation are discussed. The time-independent methods are based on the reflection principle...

  8. Iodine photodissociation laser SOFIA with MOPO-HF as a solid-state oscillator

    Czech Academy of Sciences Publication Activity Database

    Dostál, Jan; Turčičová, Hana; Králiková, Božena; Král, Lukáš; Huynh, J.

    2009-01-01

    Roč. 97, č. 3 (2009), 687-694 ISSN 0946-2171 R&D Projects: GA ČR GA202/06/0814; GA MŠk(CZ) LC528; GA MŠk LN00A100 Grant - others:EC - 6FP LASERLAB-EUROPE(XE) RII3-CT-2003-506350 Program:FP6 Institutional research plan: CEZ:AV0Z10100523 Keywords : Iodine photodissociation laser * optical parametric amplification * chirped pulse * optical synchronization * stabilization of wavelength and pointing Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.992, year: 2009

  9. Diabatic potential-optimized discrete variable representation: application to photodissociation process of the CO molecule

    International Nuclear Information System (INIS)

    Bitencourt, Ana Carla P; Prudente, Frederico V; Vianna, Jose David M

    2007-01-01

    We propose a new numerically optimized discrete variable representation using eigenstates of diabatic Hamiltonians. This procedure provides an efficient method to solve non-adiabatic coupling problems since the generated basis sets take into account information on the diabatic potentials. The method is applied to the B 1 Σ + - D' 1 Σ + Rydberg-valence predissociation interaction in the CO molecule. Here we give an account of the discrete variable representation and present the procedure for the calculation of its optimized version, which we apply to obtain the total photodissociation cross sections of the CO molecule

  10. New ab initio potential surfaces and three-dimensional quantum dynamics for transition state spectroscopy in ozone photodissociation

    Science.gov (United States)

    Yamashita, Koichi; Morokuma, Keiji; Le Quéré, Frederic; Leforestier, Claude

    1992-04-01

    New ab initio potential energy surfaces (PESs) of the ground and B ( 1B 2) states of ozone have been calculated with the CASSCF-SECI/DZP method to describe the three-dimensional photodissociation process. The dissociation energy of the ground state and the vertical barrier height of the B PES are obtained to be 0.88 and 1.34 eV, respectively, in better agreement with the experimental values than the previous calculation. The photodissociation autocorrelation function, calculated on the new B PES, based on exact three-dimensional quantum dynamics, reproduces well the main recurrence feature extracted from the experimental spectra.

  11. Forensic Chemistry

    Science.gov (United States)

    Bell, Suzanne

    2009-07-01

    Forensic chemistry is unique among chemical sciences in that its research, practice, and presentation must meet the needs of both the scientific and the legal communities. As such, forensic chemistry research is applied and derivative by nature and design, and it emphasizes metrology (the science of measurement) and validation. Forensic chemistry has moved away from its analytical roots and is incorporating a broader spectrum of chemical sciences. Existing forensic practices are being revisited as the purview of forensic chemistry extends outward from drug analysis and toxicology into such diverse areas as combustion chemistry, materials science, and pattern evidence.

  12. Interpreting locomotor biomechanics from the morphology of human footprints.

    Science.gov (United States)

    Hatala, Kevin G; Wunderlich, Roshna E; Dingwall, Heather L; Richmond, Brian G

    2016-01-01

    Fossil hominin footprints offer unique direct windows to the locomotor behaviors of our ancestors. These data could allow a clearer understanding of the evolution of human locomotion by circumventing issues associated with indirect interpretations of habitual locomotor patterns from fossil skeletal material. However, before we can use fossil hominin footprints to understand better the evolution of human locomotion, we must first develop an understanding of how locomotor biomechanics are preserved in, and can be inferred from, footprint morphologies. In this experimental study, 41 habitually barefoot modern humans created footprints under controlled conditions in which variables related to locomotor biomechanics could be quantified. Measurements of regional topography (depth) were taken from 3D models of those footprints, and principal components analysis was used to identify orthogonal axes that described the largest proportions of topographic variance within the human experimental sample. Linear mixed effects models were used to quantify the influences of biomechanical variables on the first five principal axes of footprint topographic variation, thus providing new information on the biomechanical variables most evidently expressed in the morphology of human footprints. The footprint's overall depth was considered as a confounding variable, since biomechanics may be linked to the extent to which a substrate deforms. Three of five axes showed statistically significant relationships with variables related to both locomotor biomechanics and substrate displacement; one axis was influenced only by biomechanics and another only by the overall depth of the footprint. Principal axes of footprint morphological variation were significantly related to gait type (walking or running), kinematics of the hip and ankle joints and the distribution of pressure beneath the foot. These results provide the first quantitative framework for developing hypotheses regarding the

  13. Carbon and environmental footprinting of global biofuel production

    OpenAIRE

    Hammond, Geoff P.; Seth, S.M.

    2013-01-01

    The carbon and environmental footprints associated with the global production of biofuels have been computed from a baseline of 2007-2009 out until 2019. Estimates of future global biofuel production were adopted from OECD-FAO and related projections. In order to determine the footprints associated with these (essentially 'first generation') biofuel resources, the overall environmental footprint was disaggregated into bioproductive land, built land, carbon, embodied energy, materials and wast...

  14. CO product energy distribution in the photodissociation of methylketene and acrolein at 193 nm

    Science.gov (United States)

    Fujimoto, G. T.; Umstead, M. E.; Lin, M. C.

    1985-04-01

    CO product vibrational energy distributions in the photodissociation of the two C3H4O isomers, methylketene (CH3CHCO) and acrolein (CH2CHCHO), at 193 nm have been measured by CO laser resonance absorption. The CO from methylketene was found to be vibrationally excited up to v=7, and from acrolein v=6, with average vibrational energies of 3.4±0.3 and 2.7±0.7 kcal/mol, respectively. The similarities observed in the appearance times and in the vibrational energy content of the CO formed in the two systems support our previous conclusion that in the case of acrolein isomerization to methylketene takes place prior to the dissociation process: CH2CHCHO+hν→CH3CHCO*†→CH3CH+CO†. The CO vibrational energy distributions observed in both systems agree closely with the statistical distribution predicted assuming that ethylidene rather than ethylene is formed in the photodissociation reaction.

  15. Design of a formaldehyde photodissociation process for carbon and oxygen isotope separation

    International Nuclear Information System (INIS)

    Stern, R.C.; Scheibner, K.F.

    1993-01-01

    The current shortage of 18 O has revived interest in using one step UV photodissociation of formaldehyde to enrich 13 C, 17 O and 18 O. The frequency doubled output of the copper laser pumped dye laser system currently in operation at LLNL can be used to drive this dissociation. The authors use a simple kinetics model and their experience with Atomic Vapor Laser Isotope Separation (AVLIS) process design to examine the relative merits of different designs for a formaldehyde photodissociation process. Given values for the molecular photoabsorption cross section, partition function, spectroscopic selectivity, collisional exchange and quenching cross sections (all as parameters), they perform a partial optimization in the space of illuminated area, formaldehyde pressure in each stage, and formaldehyde residence time in each stage. They examine the effect of cascade design (heads and tails staging) on molecule and photon utilization for each of the three isotope separation missions, and look in one case at the system's response to different ratios of laser to formaldehyde costs. Finally, they examine the relative cost of enrichment as a function of isotope and product assay. Emphasis is as much on the process design methodology, which is general, as on the specific application to formaldehyde

  16. Photodissociation dynamics of formyl fluoride (HFCO) at 193 nm: Branching ratios and distributions of kinetic energy

    International Nuclear Information System (INIS)

    Lee, H.; Wu, C.-Y.; Yang, S.K.; Lee, Y.-P.

    2005-01-01

    Following photodissociation of formyl fluoride (HFCO) at 193 nm, we detected products with fragmentation translational spectroscopy utilizing a tunable vacuum ultraviolet beam from a synchrotron for ionization. Among three primary dissociation channels observed in this work, the F-elimination channel HFCO→HCO+F dominates, with a branching ratio ∼0.66 and an average release of kinetic energy ∼55 kJ mol -1 ; about 17% of HCO further decomposes to H+CO. The H-elimination channel HFCO→FCO+H has a branching ratio ∼0.28 and an average release of kinetic energy ∼99 kJ mol -1 ; about 21% of FCO further decomposes to F+CO. The F-elimination channel likely proceeds via the S 1 surface whereas the H-elimination channel proceeds via the T 1 surface; both channels exhibit moderate barriers for dissociation. The molecular HF-elimination channel HFCO→HF+CO, correlating with the ground electronic surface, has a branching ratio of only ∼0.06; the average translational release of 93 kJ mol -1 , ∼15% of available energy, implies that the fragments are highly internally excited. Detailed mechanisms of photodissociation are discussed

  17. Carbon footprint as environmental performance indicator for the manufacturing industry

    DEFF Research Database (Denmark)

    Laurent, Alexis; Olsen, Stig Irving; Hauschild, Michael Zwicky

    2010-01-01

    With the current focus on our climate change impacts, the embodied CO2 emission or "Carbon footprint" is often used as an environmental performance indicator for our products or production activities. The ability of carbon footprint to represent other types of impact like human toxicity, and hence...... the overall environmental impact is investigated based on life cycle assessments of several materials of major relevance to manufacturing industries. The dependence of the carbon footprint on the assumed scenarios for generation of thermal and electrical energy in the life cycle of the materials is analyzed......, and the appropriateness of carbon footprint as an overall indicator of the environmental performance is discussed....

  18. Holocene footprints in Namibia: the influence of substrate on footprint variability.

    Science.gov (United States)

    Morse, Sarita A; Bennett, Matthew R; Liutkus-Pierce, Cynthia; Thackeray, Francis; McClymont, Juliet; Savage, Russell; Crompton, Robin H

    2013-06-01

    We report a Holocene human and animal footprint site from the Namib Sand Sea, south of Walvis Bay, Namibia. Using these data, we explore intratrail footprint variability associated with small variations in substrate properties using a "whole foot" analytical technique developed for the studies in human ichnology. We demonstrate high levels of intratrail variability as a result of variations in grain size, depositional moisture content, and the degree of sediment disturbance, all of which determine the bearing capacity of the substrate. The two principal trails were examined, which had consistent stride and step lengths, and as such variations in print typology were primarily controlled by substrate rather than locomotor mechanics. Footprint typology varies with bearing capacity such that firm substrates show limited impressions associated with areas of peak plantar pressure, whereas softer substrates are associated with deep prints with narrow heels and reduced medial longitudinal arches. Substrates of medium bearing capacity give displacement rims and proximal movement of sediment, which obscures the true form of the medial longitudinal arch. A simple conceptual model is offered which summarizes these conclusions and is presented as a basis for further investigation into the control of substrate on footprint typology. The method, model, and results presented here are essential in the interpretation of any sites of greater paleoanthropological significance, such as recently reported from Ileret (1.5 Ma, Kenya; Bennett et al.: Science 323 (2009) 1197-1201). Copyright © 2013 Wiley Periodicals, Inc.

  19. Solar Powered Automated Pipe Water Management System, Water Footprint and Carbon Footprint in Soybean Production

    Science.gov (United States)

    Satyanto, K. S.; Abang, Z. E.; Arif, C.; Yanuar, J. P. M.

    2018-05-01

    An automatic water management system for agriculture land was developed based on mini PC as controller to manage irrigation and drainage. The system was integrated with perforated pipe network installed below the soil surface to enable water flow in and out through the network, and so water table of the land can be set at a certain level. The system was operated by using solar power electricity supply to power up water level and soil moisture sensors, Raspberry Pi controller and motorized valve actuator. This study aims to implement the system in controlling water level at a soybean production land, and further to observe water footprint and carbon footprint contribution of the soybean production process with application of the automated system. The water level of the field can be controlled around 19 cm from the base. Crop water requirement was calculated using Penman-Monteith approach, with the productivity of soybean 3.57t/ha, total water footprint in soybean production is 872.01 m3/t. Carbon footprint was calculated due to the use of solar power electric supply system and during the soybean production emission was estimated equal to 1.85 kg of CO2.

  20. The carbon footprint of Australian health care.

    Science.gov (United States)

    Malik, Arunima; Lenzen, Manfred; McAlister, Scott; McGain, Forbes

    2018-01-01

    Carbon footprints stemming from health care have been found to be variable, from 3% of the total national CO 2 equivalent (CO 2 e) emissions in England to 10% of the national CO 2 e emissions in the USA. We aimed to measure the carbon footprint of Australia's health-care system. We did an observational economic input-output lifecycle assessment of Australia's health-care system. All expenditure data were obtained from the 15 sectors of the Australian Institute of Health and Welfare for the financial year 2014-15. The Australian Industrial Ecology Virtual Laboratory (IELab) data were used to obtain CO 2 e emissions per AUS$ spent on health care. In 2014-15 Australia spent $161·6 billion on health care that led to CO 2 e emissions of about 35 772 (68% CI 25 398-46 146) kilotonnes. Australia's total CO 2 e emissions in 2014-15 were 494 930 kilotonnes, thus health care represented 35 772 (7%) of 494 930 kilotonnes total CO 2 e emissions in Australia. The five most important sectors within health care in decreasing order of total CO 2 e emissions were: public hospitals (12 295 [34%] of 35 772 kilotonnes CO 2 e), private hospitals (3635 kilotonnes [10%]), other medications (3347 kilotonnes [9%]), benefit-paid drugs (3257 kilotonnes [9%]), and capital expenditure for buildings (2776 kilotonnes [8%]). The carbon footprint attributed to health care was 7% of Australia's total; with hospitals and pharmaceuticals the major contributors. We quantified Australian carbon footprint attributed to health care and identified health-care sectors that could be ameliorated. Our results suggest the need for carbon-efficient procedures, including greater public health measures, to lower the impact of health-care services on the environment. None. Copyright © 2018 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license. Published by Elsevier Ltd.. All rights reserved.

  1. The Ecological Footprint of Industrialized countries

    Directory of Open Access Journals (Sweden)

    Irene Frassoldati

    2014-12-01

    Full Text Available To compare the carbon footprint of different nations and the per capita for each country allows us to visualize a problem often underestimated by our systems of production and consumption, which is based on inequality. There is a need to work on this problem because in sharing the liability and the global consequences, the effects that cannot continue, reveals a series of possibilities. It would require 3-6 planets equal to Earth in order to sustain a lifestyle like that of an inhabitant of North America in order to supporst all inhabitants on Earth.

  2. ROVIBRATIONALLY RESOLVED DIRECT PHOTODISSOCIATION THROUGH THE LYMAN AND WERNER TRANSITIONS OF H2 FOR FUV/X-RAY-IRRADIATED ENVIRONMENTS

    International Nuclear Information System (INIS)

    Gay, C. D.; Porter, R. L.; Stancil, P. C.; Abel, N. P.; Ferland, G. J.; Shaw, G.; Van Hoof, P. A. M.; Williams, R. J. R.

    2012-01-01

    Using ab initio potential curves and dipole transition moments, cross-section calculations were performed for the direct continuum photodissociation of H 2 through the B 1 Σ + u 1 Σ + g (Lyman) and C 1 Π u 1 Σ + g (Werner) transitions. Partial cross-sections were obtained for wavelengths from 100 Å to the dissociation threshold between the upper electronic state and each of the 301 bound rovibrational levels v''J'' within the ground electronic state. The resulting cross-sections are incorporated into three representative classes of interstellar gas models: diffuse clouds, photon-dominated regions, and X-ray-dominated regions (XDRs). The models, which used the CLOUDY plasma/molecular spectra simulation code, demonstrate that direct photodissociation is comparable to fluorescent dissociation (or spontaneous radiative dissociation, the Solomon process) as an H 2 destruction mechanism in intense far-ultraviolet or X-ray-irradiated gas. In particular, changes in H 2 rotational column densities are found to be as large as 20% in the XDR model with the inclusion of direct photodissociation. The photodestruction rate from some high-lying rovibrational levels can be enhanced by pumping from H Lyβ due to a wavelength coincidence with cross-section resonances resulting from quasi-bound levels of the upper electronic states. Given the relatively large size of the photodissociation data set, a strategy is described to create truncated, but reliable, cross-section data consistent with the wavelength resolving power of typical observations.

  3. Photodissociation dynamics of 2-chloro-6-nitrotoluene and nitrocyclopentane in gas phase: Laser-induced fluorescence detection of OH

    Energy Technology Data Exchange (ETDEWEB)

    Kawade, Monali N.; Saha, Ankur; Upadhyaya, Hari P.; Kumar, Awadhesh; Naik, Prakash D., E-mail: pdnaik@barc.gov.in

    2014-10-31

    Highlights: • Photodissociation studies on chloronitrotoluene (ClNT) and nitrocyclopentane (NCP). • Nascent OH product detected state selectively using laser induced fluorescence. • OH formation takes place from the ground electronic state with an exit barrier. • UV photodissociation dynamics of ClNT and NCP is different. - Abstract: Photodissociation of 2-chloro-6-nitrotoluene (ClNT) at 193, 248 and 266 nm and nitrocyclopentane (NCP) at 193 nm leads to the formation of OH, as detected by laser-induced fluorescence (LIF). The nascent OH produced from the photolysis of ClNT at all the wavelengths is vibrationally cold, with the Boltzmann type rotational state distributions. However, the nascent OH product from NCP is in the ground and vibrationally excited states with the measured average relative population in ν{sup ″}=1 to that in ν{sup ″}=0 of 0.12 ± 0.03, and these levels are characterized by rotational temperatures of 650 ± 180 K and 1570 ± 90 K, respectively. The translational energy partitioned in the OH fragment has been measured for photodissociation of both ClNT and NCP. On the basis of both the experimental results and the ground state molecular orbital (MO) calculations, a plausible mechanism for the OH formation has been proposed.

  4. Organic chemistry

    International Nuclear Information System (INIS)

    2003-08-01

    This book with sixteen chapter explains organic chemistry on linkage isomerism such as alkane, cycloalkane, alkene, aromatic compounds, stereo selective isomerization, aromatic compounds, stereo selective isomerization, organic compounds, stereo selective isomerization, organic halogen compound, alcohol, ether, aldehyde and ketone, carboxylic acid, dicarboxylic acid, fat and detergent, amino, carbohydrate, amino acid and protein, nucleotide and nucleic acid and spectroscopy, a polymer and medical chemistry. Each chapter has introduction structure and characteristic and using of organic chemistry.

  5. Radiation chemistry

    Energy Technology Data Exchange (ETDEWEB)

    None

    1973-07-01

    Research progress is reported on radiation chemistry of heavy elements that includes the following topics: radiation chemistry of plutonium in nitric acid solutions (spectrophotometric analysis and gamma radiolysis of Pu(IV) and Pu(VI) in nitric acid solution); EPR studies of intermediates formed in radiolytic reactions with aqueous medium; two-phase radiolysis and its effect on the distribution coefficient of plutonium; and radiation chemistry of nitric acid. (DHM)

  6. Technetium chemistry

    International Nuclear Information System (INIS)

    Burns, C.; Bryan, J.; Cotton, F.; Ott, K.; Kubas, G.; Haefner, S.; Barrera, J.; Hall, K.; Burrell, A.

    1996-01-01

    Technetium chemistry is a young and developing field. Despite the limited knowledge of its chemistry, technetium is the workhorse for nuclear medicine. Technetium is also a significant environmental concern because it is formed as a byproduct of nuclear weapons production and fission-power generators. Development of new technetium radio-pharmaceuticals and effective environmental control depends strongly upon knowledge of basic technetium chemistry. The authors performed research into the basic coordination and organometallic chemistry of technetium and used this knowledge to address nuclear medicine and environmental applications. This is the final report of a three-year Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL)

  7. Chemistry Technology

    Data.gov (United States)

    Federal Laboratory Consortium — Chemistry technology experts at NCATS engage in a variety of innovative translational research activities, including:Design of bioactive small molecules.Development...

  8. Product carbon footprint developments and gaps

    DEFF Research Database (Denmark)

    Kronborg Jensen, Jesper

    2012-01-01

    Purpose - Over the last decade, multiple initiatives have been undertaken to learn how to capture the carbon footprint of a supply chain at a product level. The purpose of this paper is to focus on the process of standardization to secure consistency of product carbon footprinting (PCF) and to ou....../value - Papers that outline the standardization process for PCF have been examined, but this paper adds value by categorizing the field, outlining the latest standards, and by being the first paper to compare standards for PCF on selected criteria and identify gaps....... when conducting a PCF, and a paradox exists concerning methods for securing future standardization of PCF. Research limitations/implications - Standards for evaluating emission of greenhouse gases (GHGs) in supply chains are evaluated without consideration of other environmental impacts. In addition......, the research only compares international standards, thereby excluding national initiatives. Practical implications - Standardization efforts can be expected to shape the future practice of measuring emission of GHGs in companies and supply chains which provides a framework for reducing impacts. Originality...

  9. The pectoralis major footprint: An anatomical study

    Directory of Open Access Journals (Sweden)

    Eduardo Antonio de Figueired

    2013-12-01

    Full Text Available Objective: To study the insertion of the pectoralis major tendon to the humerus, through knowledge of its dimensions in the coronal and sagittal planes. Methods: Twenty shoulders from 10 cadavers were dissected and the pectoralis major tendon insertion on the humerus was identified and isolated. The dimensions of its "footprint" (proximal to distal and medial to lateral borders and the distance from the top edge of the pectoralis major tendon to apex of the humeral head structures were measured. Results: The average proximal to distal border length was 80.8 mm (range: 70 -90 and the medial-to-lateral border length was 6.1 mm (5 -7. The average distance (and range from the apex of the pectoralis major tendon to the humeral head was 59.3 mm. Conclusions: We demonstrate that the insertion of the pectoralis major tendon is laminar, and the pectoralis major tendon has an average footprint height and width of 80.8 mm and 6.1 mm, respectively.

  10. European Water Footprint Scenarios for 2050

    Directory of Open Access Journals (Sweden)

    A. Ertug Ercin

    2016-05-01

    Full Text Available This study develops water footprint scenarios for Europe for 2050, at the country level, based on projections regarding population and economic growth, production and trade patterns, consumption patterns (diets and bioenergy use and technological development. The objective is to estimate possible future changes in the green, blue and grey water footprint (WF of production and consumption, to analyze the main drivers of projected changes and to assess Europe’s future dependence on water resources elsewhere in the world. We develop four scenarios, considering globalization versus regional self-sufficiency, and development driven by economic objectives versus development driven by social and environmental objectives. The study shows that the most critical driver of change affecting Europe’s future WF is the consumption pattern. The WFs of both production and consumption in Western Europe increase under scenarios with high meat consumption and decrease with low-meat scenarios. Besides, additional water demands from increasing biofuel needs will put further pressure on European water resources. The European countries with a large ratio of external to total WF of consumption in 2000 decrease their dependencies on foreign water resources in 2050.

  11. Marine Ecological Footprint of Italian Mediterranean Fisheries

    Directory of Open Access Journals (Sweden)

    Federica de Leo

    2014-10-01

    Full Text Available The capacity of marine and coastal ecosystems to sustain seafood production and consumption is seldom accounted for and is not included in the signals that guide economic development. In this article, we review estimates of marine and coastal areas aimed at sustaining catches for seafood consumption. The aim of this paper is the assessment of the interactions between the environment, intended as a set of ecological subsystems in natural equilibrium, including the marine ecosystem, and the process of fisheries systems. In particular we analyze fisheries in Italy, which is the third biggest economy and the greatest consumer of seafood in the Eurozone, conducting an in-depth analysis of the Marine Ecological Footprint (MEF that evaluates the marine ecosystem area exploited by human populations to supply seafood and other marine products and services. The positioning of Italian fisheries shows a level of sustainability next to the threshold value. The analysis in the present study highlights the importance of absolute indicators in providing rough estimates about human dependence on ecological systems and recognizes the importance of those indicators, such as the Marine Footprint (expressed in % of Primary Production Required/Primary Production, in ensuring a high level of precision and accuracy in quantifying human activity impact on the environment.

  12. Carbon footprint from dairy farming system

    DEFF Research Database (Denmark)

    Della Riva, A.; Kristensen, Troels; De Marchi1, M.

    2014-01-01

    Aim of the present study was to estimate the carbon footprint (CF) of milk production at farm gate considering two dairy cattle breeds, Holstein Friesian (HF) and Jersey (JE). Using Italian inventory data the emissions of CO2eq per kg ECM for dairy herds of HF and JE breed were estimated. The res......Aim of the present study was to estimate the carbon footprint (CF) of milk production at farm gate considering two dairy cattle breeds, Holstein Friesian (HF) and Jersey (JE). Using Italian inventory data the emissions of CO2eq per kg ECM for dairy herds of HF and JE breed were estimated....... The results show 0.80 kg CO2eq/kg ECM in JE herd, while 0.96 kg CO2eq/kg ECM in HF herd. The main differences were due to the level of dry matter intake, milk yield and fertility traits. Indeed, JE herd showed a lower milk yield than HF herd, a lower DMI and better fertility, determining less production...

  13. ADDRESSING WATER FOOTPRINT CONCEPT: A DEMONSTRABLE STRATEGY FOR PAPERMAKING INDUSTRY

    Directory of Open Access Journals (Sweden)

    Jing Shen,

    2012-05-01

    Full Text Available Since the introduction of the water footprint concept in 2002, in the context of humankind’s ever-increasing awareness of the valuable global freshwater resources, it has received more and more attention. The application of this relatively new concept has been expected to provide ecological and environmental benefits. For the water-intensive papermaking industry, it seems that water footprint needs to be addressed. The water footprint of cellulosic paper can be divided into three components, including its green water footprint, blue water footprint, and grey water footprint, which may be accounted for by considering the individual contributions of wood or non-wood materials, pulp production processes, effluent discharge to the receiving water bodies, process chemicals and additives, energy consumption, etc. In the literature, the accounting of water footprint during the whole production chain of cellulosic paper is already available, and relevant research findings can provide useful insights into the application of the concept; however, further development of the accounting methodologies is much needed, so that the quantitative and qualitative evaluation of water footprint can be internationally recognized, certified, and standardized. Although there are ongoing or upcoming debates and challenges associated with the concept, its application to papermaking industry may be expected to provide various encouraging possibilities and impacts.

  14. Double-counting in supply chain carbon footprinting

    NARCIS (Netherlands)

    Caro, F.; Corbett, C.J.; Tan, T.; Zuidwijk, R.A.

    2013-01-01

    Carbon footprinting is a tool for firms to determine the total greenhouse gas (GHG) emissions associated with their supply chain or with a unit of final product or service. Carbon footprinting typically aims to identify where best to invest in emission reduction efforts, and/or to determine the

  15. Analysis of the carbon footprint of coastal protection systems

    NARCIS (Netherlands)

    Labrujere, A.L.; Verhagen, H.J.

    2012-01-01

    When calculating the Carbon Footprint for a product or service, a direct link is made between the total amount of consumed energy and the produced amount of carbon dioxide during production. For that reason calculating the carbon footprint of various alternatives is a very straightforward method to

  16. Klimaregnskab og Carbon Footprint beregning for Kommunekemi a/s

    DEFF Research Database (Denmark)

    Leinikka Dall, Ole; Wenzel, Henrik

    2009-01-01

    Klimaregnskab for anlægget i Nyborg og carbon footprint for: -forbrænding -uorganisk behandling -halmaskeanlæg Afrapporteret på tryk og indtastet i Simapro......Klimaregnskab for anlægget i Nyborg og carbon footprint for: -forbrænding -uorganisk behandling -halmaskeanlæg Afrapporteret på tryk og indtastet i Simapro...

  17. Teaching Quantitative Reasoning for Nonscience Majors through Carbon Footprint Analysis

    Science.gov (United States)

    Boose, David L.

    2014-01-01

    Quantitative reasoning is a key intellectual skill, applicable across disciplines and best taught in the context of authentic, relevant problems. Here, I describe and assess a laboratory exercise that has students calculate their "carbon footprint" and evaluate the impacts of various behavior choices on that footprint. Students gather…

  18. Current organic chemistry

    National Research Council Canada - National Science Library

    1997-01-01

    Provides in depth reviews on current progress in the fields of asymmetric synthesis, organometallic chemistry, bioorganic chemistry, heterocyclic chemistry, natural product chemistry, and analytical...

  19. Ecological footprint and food consumption in Minna, Nigeria

    International Nuclear Information System (INIS)

    Razack, N T A A; Ludin, A N M

    2014-01-01

    Cities all over the world are growing and will continue to grow as development is tilted toward development at the expense of the rural area. As a result of this there is need for development of housing that constructed at the urban fringes. There are many tools to measure sustainability of a city and one of them is Ecological Footprint. This paper looked at the Ecological Footprint and food consumption Minna, Nigeria. The paper evaluates the effectiveness of Ecological Footprint in the context of urban development. The survey revealed that food contributed 38.77% of the Ecological Footprint of Minna. This is as a result of the lifestyle of the people. It was concluded that the Ecological Footprint of Minna (1.096gha) is lower than the national bio-capacity (1.24gha), which therefore make city sustainable. Therefore, the people of Minna have to develop a lifestyle that will be sustainable better than the present practice

  20. Nuclear chemistry

    International Nuclear Information System (INIS)

    Vertes, A.; Kiss, I.

    1987-01-01

    This book is an introduction to the application of nuclear science in modern chemistry. The first group of chapters discuss the basic phenomena and concepts of nuclear physics with emphasis on their relation to chemical problems, including the main properties and the composition of atomic nuclei, nuclear reactions, radioactive decay and interactions of radiation with matter. These chapters provide the basis for understanding the following chapters which encompass the wide scope of nuclear chemistry. The methods of the investigation of chemical structure based on the interaction of nuclear radiation with matter including positronium chemistry and other exotic atoms is elaborated in particular detail. Separate chapters are devoted to the use of radioactive tracers, the chemical consequences of nuclear processes (i.e. hot atom chemistry), radiation chemistry, isotope effects and their applications, and the operation of nuclear reactors

  1. Nuclear chemistry

    International Nuclear Information System (INIS)

    Vertes, A.; Kiss, I.

    1987-01-01

    This book is an introduction to the application of nuclear science in modern chemistry. The first group of chapters discuss the basic phenomena and concepts of nuclear physics with emphasis on their relation to chemical problems, including the main properties and the composition of atomic nuclei, nuclear reactions, radioactive decay and interactions of radiation with matter. These chapters provide the basis for understanding the following chapters which encompass the wide scope of nuclear chemistry. The methods of the investigation of chemical structure based on the interaction of nuclear radiation with matter including positronium chemistry and other exotic atoms is elaborated in particular detail. Separate chapters are devoted to the use of radioactive tracers, the chemical consequences of nuclear processes (i.e. hot atom chemistry), radiation chemistry, isotope effects and their applications, and the operation of nuclear reactors. (Auth.)

  2. Three-dimensional photodissociation in strong laser fields: Memory-kernel effective-mode expansion

    International Nuclear Information System (INIS)

    Li Xuan; Thanopulos, Ioannis; Shapiro, Moshe

    2011-01-01

    We introduce a method for the efficient computation of non-Markovian quantum dynamics for strong (and time-dependent) system-bath interactions. The past history of the system dynamics is incorporated by expanding the memory kernel in exponential functions thereby transforming in an exact fashion the non-Markovian integrodifferential equations into a (larger) set of ''effective modes'' differential equations (EMDE). We have devised a method which easily diagonalizes the EMDE, thereby allowing for the efficient construction of an adiabatic basis and the fast propagation of the EMDE in time. We have applied this method to three-dimensional photodissociation of the H 2 + molecule by strong laser fields. Our calculations properly include resonance-Raman scattering via the continuum, resulting in extensive rotational and vibrational excitations. The calculated final kinetic and angular distribution of the photofragments are in overall excellent agreement with experiments, both when transform-limited pulses and when chirped pulses are used.

  3. Product fine-structure resolved photodissociation dynamics: The A band of H{sub 2}O

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Linsen [Institute of Theoretical and Computational Chemistry, Key Laboratory of Mesoscopic Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093 (China); Xie, Daiqian, E-mail: dqxie@nju.edu.cn, E-mail: hguo@unm.edu [Institute of Theoretical and Computational Chemistry, Key Laboratory of Mesoscopic Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093 (China); Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Sun, Zhigang [State Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical and Computational Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China); Guo, Hua, E-mail: dqxie@nju.edu.cn, E-mail: hguo@unm.edu [Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico 87131 (United States)

    2014-01-14

    The photodissociation dynamics of H{sub 2}O in its first absorption band is investigated on an accurate potential energy surface based on a large number of high-level ab initio points. Several ro-vibrational states of the parent molecule are considered. Different from most previous theoretical studies, the spin-orbit and Λ-doublet populations of the open-shell OH fragment are reported from full-dimensional wave packet calculations. The populations of the two spin-orbit manifolds are in most cases close to the statistical limit, but the Λ-doublet is dominated by the A{sup ″} component, thanks largely to the fast in-plane dissociation of H{sub 2}O(A{sup ~1}A{sup ′′}). Comparisons with experimental data and a Franck-Condon model are generally very good, although some discrepancies exist.

  4. Potential energy surface from spectroscopic data in the photodissociation of polyatomic molecules

    International Nuclear Information System (INIS)

    Kim, Hwa Joong; Kim, Young Sik

    2001-01-01

    The time-dependent tracking inversion method is studied to extract the potential energy surface of the electronic excited state in the photodissociation of triatomic molecules. Based on the relay of the regularized inversion procedure and time-dependent wave packet propagation, the algorithm extracts the underlying potential energy surface piece by tracking the time-dependent data, which can be synthesized from Raman excitation profiles. We have demonstrated the algorithm to extract the potential energy surface of electronic excited state for NO 2 molecule where the wave packet split on a saddle-shaped surface. Finally, we describe the merits of the time-dependent tracking inversion method compared with the time-dependent inversion method and discussed several extensions of the algorithm

  5. Product fine-structure resolved photodissociation dynamics: The A band of H2O

    International Nuclear Information System (INIS)

    Zhou, Linsen; Xie, Daiqian; Sun, Zhigang; Guo, Hua

    2014-01-01

    The photodissociation dynamics of H 2 O in its first absorption band is investigated on an accurate potential energy surface based on a large number of high-level ab initio points. Several ro-vibrational states of the parent molecule are considered. Different from most previous theoretical studies, the spin-orbit and Λ-doublet populations of the open-shell OH fragment are reported from full-dimensional wave packet calculations. The populations of the two spin-orbit manifolds are in most cases close to the statistical limit, but the Λ-doublet is dominated by the A ″ component, thanks largely to the fast in-plane dissociation of H 2 O(A ~1 A ′′ ). Comparisons with experimental data and a Franck-Condon model are generally very good, although some discrepancies exist

  6. Formation and femtosecond photodissociation of Agn+andAun+ complexes with benzene and carbon monoxide

    Science.gov (United States)

    Popolan, Denisia M.; Bernhardt, Thorsten M.

    2009-02-01

    The reactions of free, size selected gold and silver cluster cations Agn+andAun+ ( n = 3, 5) with C 6H 6 as well as with a mixture of C 6H 6 and CO were investigated in a radio frequency ion trap under multiple collision condition. While benzene was found to react with all investigated metal clusters exhibiting size dependent adsorbate coverages, the coadsorption of C 6H 6 and CO was only observed on the gold clusters. Photodissociation experiments at 353 and 393 nm, respectively, provided indications for charge transfer induced fragmentation in the case of the silver cluster-benzene complexes. In particular, for Ag(CH)2+ the femtosecond time resolved fragmentation dynamics could be measured.

  7. Photodissociation of ethylbenzene and n-propylbenzene in a molecular beam

    Science.gov (United States)

    Huang, Cheng-Liang; Jiang, Jyh-Chiang; Lee, Yuan T.; Ni, Chi-Kung

    2002-10-01

    The photodissociation of jet-cooled ethylbenzene and n-propylbenzene at both 193 and 248 nm was studied using vacuum ultraviolet photoionization/multimass ion imaging techniques. The photofragment translational energy distributions from both the molecules obtained at 193 nm show that the probability of portioning energy to product translational energy decreases monotonically with increasing translational energy. They indicate that the dissociation occurs from the ground electronic state. However, the photofragment translational energy distributions from both molecules obtained at 248 nm contain a fast and a slow component. 75% of ethylbenzene and 80% of n-propylbenzene following the 248 nm photoexcitation dissociate from electronic excited state, resulting in the fast component. The remaining 25% of ethylbenzene and 20% of n-propylbenzene dissociate through the ground electronic state, giving rise to the slow component. A comparison with an ab initio calculation suggests that the dissociation from the first triplet state corresponds to the fast component in translational energy distribution.

  8. Schrödinger–Langevin equation with quantum trajectories for photodissociation dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Chou, Chia-Chun, E-mail: ccchou@mx.nthu.edu.tw

    2017-02-15

    The Schrödinger–Langevin equation is integrated to study the wave packet dynamics of quantum systems subject to frictional effects by propagating an ensemble of quantum trajectories. The equations of motion for the complex action and quantum trajectories are derived from the Schrödinger–Langevin equation. The moving least squares approach is used to evaluate the spatial derivatives of the complex action required for the integration of the equations of motion. Computational results are presented and analyzed for the evolution of a free Gaussian wave packet, a two-dimensional barrier model, and the photodissociation dynamics of NOCl. The absorption spectrum of NOCl obtained from the Schrödinger–Langevin equation displays a redshift when frictional effects increase. This computational result agrees qualitatively with the experimental results in the solution-phase photochemistry of NOCl.

  9. Photodissociation spectroscopy of the Mg + -CO2 complex and its isotopic analogs

    Science.gov (United States)

    Yeh, C. S.; Willey, K. F.; Robbins, D. L.; Pilgrim, J. S.; Duncan, M. A.

    1993-02-01

    Mg+-CO2 ion-molecule cluster complexes are produced by laser vaporization in a pulsed nozzle cluster source. The vibronic spectroscopy in these complexes is studied with mass-selected photodissociation spectroscopy in a reflectron time-of-flight mass spectrometer. Two excited electronic states are observed (2) 2Σ+ and 2Π. The 2Π state has a vibrational progression in the metal-CO2 stretching mode (ωe'=381.8 cm-1). The complexes are linear (Mg+-OCO) and are bound by the charge-quadrupole interaction. The dissociation energy (D0`) is 14.7 kcal/mol. Corresponding spectra are measured for each of the 24, 25, and 26 isotopes of magnesium. These results are compared to theoretical predictions made by Bauschlicher and co-workers.

  10. TD-DFT Insight into Photodissociation of Co-C Bond in Coenzyme B12

    Directory of Open Access Journals (Sweden)

    Pawel Michal Kozlowski

    2014-02-01

    Full Text Available Coenzyme B12 (AdoCbl is one of the most biologically active forms of vitamin B12, and continues to be a topic of active research interest. The mechanism of Co-C bond cleavage in AdoCbl, and the corresponding enzymatic reactions are however, not well understood at the molecular level. In this work, time-dependent density functional theory (TD-DFT has been applied to investigate the photodissociation of coenzyme B12. To reduce computational cost, while retaining the major spectroscopic features of AdoCbl, a truncated model based on ribosylcobalamin (RibCbl was used to simulate Co-C photodissociation. Equilibrium geometries of RibCbl were obtained by optimization at the DFT/BP86/TZVP level of theory, and low-lying excited states were calculated by TD-DFT using the same functional and basis set. The calculated singlet states, and absorption spectra were simulated in both the gas phase, and water, using the polarizable continuum model (PCM. Both spectra were in reasonable agreement with experimental data, and potential energy curves based on vertical excitations were plotted to explore the nature of Co-C bond dissociation. It was found that a repulsive 3(σCo-C → σ*Co-C triplet state became dissociative at large Co-C bond distance, similar to a previous observation for methylcobalamin (MeCbl. Furthermore, potential energy surfaces (PESs obtained as a function of both Co-CRib and Co-NIm distances, identify the S1 state as a key intermediate generated during photoexcitation of RibCbl, attributed to a mixture of a MLCT (metal-to-ligand charge transfer and a σ bonding-ligand charge transfer (SBLCT states.

  11. The environmental cost of subsistence: Optimizing diets to minimize footprints

    International Nuclear Information System (INIS)

    Gephart, Jessica A.; Davis, Kyle F.; Emery, Kyle A.; Leach, Allison M.; Galloway, James N.; Pace, Michael L.

    2016-01-01

    The question of how to minimize monetary cost while meeting basic nutrient requirements (a subsistence diet) was posed by George Stigler in 1945. The problem, known as Stigler's diet problem, was famously solved using the simplex algorithm. Today, we are not only concerned with the monetary cost of food, but also the environmental cost. Efforts to quantify environmental impacts led to the development of footprint (FP) indicators. The environmental footprints of food production span multiple dimensions, including greenhouse gas emissions (carbon footprint), nitrogen release (nitrogen footprint), water use (blue and green water footprint) and land use (land footprint), and a diet minimizing one of these impacts could result in higher impacts in another dimension. In this study based on nutritional and population data for the United States, we identify diets that minimize each of these four footprints subject to nutrient constraints. We then calculate tradeoffs by taking the composition of each footprint's minimum diet and calculating the other three footprints. We find that diets for the minimized footprints tend to be similar for the four footprints, suggesting there are generally synergies, rather than tradeoffs, among low footprint diets. Plant-based food and seafood (fish and other aquatic foods) commonly appear in minimized diets and tend to most efficiently supply macronutrients and micronutrients, respectively. Livestock products rarely appear in minimized diets, suggesting these foods tend to be less efficient from an environmental perspective, even when nutrient content is considered. The results' emphasis on seafood is complicated by the environmental impacts of aquaculture versus capture fisheries, increasing in aquaculture, and shifting compositions of aquaculture feeds. While this analysis does not make specific diet recommendations, our approach demonstrates potential environmental synergies of plant- and seafood-based diets. As a result, this study

  12. The environmental cost of subsistence: Optimizing diets to minimize footprints

    Energy Technology Data Exchange (ETDEWEB)

    Gephart, Jessica A.; Davis, Kyle F. [University of Virginia, Department of Environmental Sciences, 291 McCormick Road, Charlottesville, VA 22904 (United States); Emery, Kyle A. [University of Virginia, Department of Environmental Sciences, 291 McCormick Road, Charlottesville, VA 22904 (United States); University of California, Santa Barbara. Marine Science Institute, Santa Barbara, CA 93106 (United States); Leach, Allison M. [University of New Hampshire, 107 Nesmith Hall, 131 Main Street, Durham, NH, 03824 (United States); Galloway, James N.; Pace, Michael L. [University of Virginia, Department of Environmental Sciences, 291 McCormick Road, Charlottesville, VA 22904 (United States)

    2016-05-15

    The question of how to minimize monetary cost while meeting basic nutrient requirements (a subsistence diet) was posed by George Stigler in 1945. The problem, known as Stigler's diet problem, was famously solved using the simplex algorithm. Today, we are not only concerned with the monetary cost of food, but also the environmental cost. Efforts to quantify environmental impacts led to the development of footprint (FP) indicators. The environmental footprints of food production span multiple dimensions, including greenhouse gas emissions (carbon footprint), nitrogen release (nitrogen footprint), water use (blue and green water footprint) and land use (land footprint), and a diet minimizing one of these impacts could result in higher impacts in another dimension. In this study based on nutritional and population data for the United States, we identify diets that minimize each of these four footprints subject to nutrient constraints. We then calculate tradeoffs by taking the composition of each footprint's minimum diet and calculating the other three footprints. We find that diets for the minimized footprints tend to be similar for the four footprints, suggesting there are generally synergies, rather than tradeoffs, among low footprint diets. Plant-based food and seafood (fish and other aquatic foods) commonly appear in minimized diets and tend to most efficiently supply macronutrients and micronutrients, respectively. Livestock products rarely appear in minimized diets, suggesting these foods tend to be less efficient from an environmental perspective, even when nutrient content is considered. The results' emphasis on seafood is complicated by the environmental impacts of aquaculture versus capture fisheries, increasing in aquaculture, and shifting compositions of aquaculture feeds. While this analysis does not make specific diet recommendations, our approach demonstrates potential environmental synergies of plant- and seafood-based diets. As a result

  13. Uk’e koley (no footprint) Project

    Energy Technology Data Exchange (ETDEWEB)

    Winnestaffer, Jessica E.D. [Chickaloon Native Village

    2014-03-30

    Chickaloon Native Village is a federally-recognized Alaska Native Tribe that has long been devoted to being a good steward to the environment, understanding that it is our responsibility to take care of the land that has been loaned to us for the short time we are here. The goal of this project was to conduct a feasibility study to assess the energy uses, loads, and efficiencies for all of our current Tribally owned and operated buildings and rental housing units, to determine if it makes economic and environmental sense to install renewable energy systems on each building to lower our carbon footprints and to decrease our dependence on fossil fuels. The goal was met and we have developed a plan for installing renewable energy systems on several Tribal buildings where the benefits will be most notable.

  14. The water footprint of land grabbing

    Science.gov (United States)

    Rulli, Maria Cristina; D'Odorico, Paolo

    2013-12-01

    increasing global demand for food, fibers, and biofuels has made investments in agriculture a priority for some governments and corporations eager to expand their agricultural production while securing good profits. Here we calculate the water appropriation associated with land deals at different negotiation and implementation stages. Using estimates of actual and potential evapotranspiration for the crops planted in the acquired land, we calculate the green and blue water appropriated by land investors under a variety of irrigation scenarios. We also determine the grey water footprint as the amount of water required to dilute to allowable standards the pollution resulting from fertilizer applications. We found that about 380 × 109 m3 yr-1 of rainwater is appropriated with the 43 million ha of reported contract area acquired by agri-investors (>240 × 109 m3 yr-1 in the 29 million ha of foreign acquisitions only). This water would be sufficient to feed ≈ 300-390 million people.

  15. Environmental and social footprints of international trade

    Science.gov (United States)

    Wiedmann, Thomas; Lenzen, Manfred

    2018-05-01

    Globalization has led to an increasing geospatial separation of production and consumption, and, as a consequence, to an unprecedented displacement of environmental and social impacts through international trade. A large proportion of total global impacts can be associated with trade, and the trend is rising. Advances in global multi-region input-output models have allowed researchers to draw detailed, international supply-chain connections between harmful production in social and environmental hotspots and affluent consumption in global centres of wealth. The general direction of impact displacement is from developed to developing countries—an increase of health impacts in China from air pollution linked to export production for the United States being one prominent example. The relocation of production across countries counteracts national mitigation policies and may negate ostensible achievements in decoupling impacts from economic growth. A comprehensive implementation of the United Nations Sustainable Development Goals therefore requires the inclusion of footprint indicators to avoid loopholes in national sustainability assessments.

  16. Quantum chemistry

    CERN Document Server

    Lowe, John P

    1993-01-01

    Praised for its appealing writing style and clear pedagogy, Lowe's Quantum Chemistry is now available in its Second Edition as a text for senior undergraduate- and graduate-level chemistry students. The book assumes little mathematical or physical sophistication and emphasizes an understanding of the techniques and results of quantum chemistry, thus enabling students to comprehend much of the current chemical literature in which quantum chemical methods or concepts are used as tools. The book begins with a six-chapter introduction of standard one-dimensional systems, the hydrogen atom,

  17. Apparatus for extraction and separation of a preferentially photo-dissociated molecular isotope into positive and negative ions by means of an electric field

    International Nuclear Information System (INIS)

    Fletcher, J.C.

    1978-01-01

    Apparatus for the separation and extraction of molecular isotopes is claimed. Molecules of one and the same isotope are preferentially photo-dissociated by a laser and an ultraviolet source, or by multi-photon absorption of laser radiation. The resultant ions are confined with a magnetic field, moved in opposite directions by an electric field, extracted from the photo-dissociation region by means of screening and accelerating grids, and collected in ducts

  18. Product carbon footprints and their uncertainties in comparative decision contexts.

    Directory of Open Access Journals (Sweden)

    Patrik J G Henriksson

    Full Text Available In response to growing awareness of climate change, requests to establish product carbon footprints have been increasing. Product carbon footprints are life cycle assessments restricted to just one impact category, global warming. Product carbon footprint studies generate life cycle inventory results, listing the environmental emissions of greenhouse gases from a product's lifecycle, and characterize these by their global warming potentials, producing product carbon footprints that are commonly communicated as point values. In the present research we show that the uncertainties surrounding these point values necessitate more sophisticated ways of communicating product carbon footprints, using different sizes of catfish (Pangasius spp. farms in Vietnam as a case study. As most product carbon footprint studies only have a comparative meaning, we used dependent sampling to produce relative results in order to increase the power for identifying environmentally superior products. We therefore argue that product carbon footprints, supported by quantitative uncertainty estimates, should be used to test hypotheses, rather than to provide point value estimates or plain confidence intervals of products' environmental performance.

  19. Ecological Footprint in relation to Climate Change Strategy in Cities

    Science.gov (United States)

    Belčáková, Ingrid; Diviaková, Andrea; Belaňová, Eliška

    2017-10-01

    Ecological footprint determines how much natural resources are consumed by an individual, city, region, state or all inhabitants of our planet in order to ensure their requirements and needs. It includes all activities, from food consumption, housing, transport to waste produced and allows us to compare particular activities and their impacts on the environment and natural resources. Ecological footprint is important issue for making sustainable development concept more popular using simplifications, which provide the public with basic information on situation on our planet. Today we know calculations of global (worldwide), national and local ecological footprints. During our research in cities, we were concentrated on calculation of city’s ecological footprint. The article tries to outline theoretical and assumptions and practical results of climate change consequences in cities of Bratislava and Nitra (Slovakia), to describe potential of mitigating adverse impacts of climate change and to provide information for general and professional public on theoretical assumptions in calculating ecological footprint. The intention is to present innovation of ecological footprint calculation, taking into consideration ecological stability of a city (with a specific focus on micro-climate functions of green areas). Present possibilities to reduce ecological footprint are presented.

  20. The nitrogen footprint tool network: a multi-institution program ...

    Science.gov (United States)

    Anthropogenic sources of reactive nitrogen have local and global impacts on air and water quality and detrimental effects on human and ecosystem health. This paper uses the nitrogen footprint tool (NFT) to determine the amount of nitrogen (N) released as a result of institutional consumption. The sectors accounted for include food (consumption and the upstream production), energy, transportation, fertilizer, research animals, and agricultural research. The NFT is then used for scenario analysis to manage and track reductions to institution N footprints, which are driven by the consumption behaviors of both the institution itself and its constituent individuals. In this paper, the first seven institution N footprint results are presented. The institution NFT network aims to develop footprints for many institutions to encourage widespread upper-level management strategies that will create significant reductions in reactive N released to the environment. Energy use and food purchases are the two largest contributors to institution N footprints. Ongoing efforts by institutions to reduce greenhouse gas emissions also help to reduce the N footprint, but the impact of food production on N pollution has not been directly addressed by the higher-ed sustainability community. The NFT Network found that institutions could reduce their N footprints by optimizing food purchasing to reduce consumption of animal products and minimize food waste, as well as reducing dependence o

  1. Materials Chemistry

    CERN Document Server

    Fahlman, Bradley D

    2011-01-01

    The 2nd edition of Materials Chemistry builds on the strengths that were recognized by a 2008 Textbook Excellence Award from the Text and Academic Authors Association (TAA). Materials Chemistry addresses inorganic-, organic-, and nano-based materials from a structure vs. property treatment, providing a suitable breadth and depth coverage of the rapidly evolving materials field. The 2nd edition continues to offer innovative coverage and practical perspective throughout. After briefly defining materials chemistry and its history, seven chapters discuss solid-state chemistry, metals, semiconducting materials, organic "soft" materials, nanomaterials, and materials characterization. All chapters have been thoroughly updated and expanded with, for example, new sections on ‘soft lithographic’ patterning, ‘click chemistry’ polymerization, nanotoxicity, graphene, as well as many biomaterials applications. The polymer and ‘soft’ materials chapter represents the largest expansion for the 2nd edition. Each ch...

  2. Analytical chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jae Seong

    1993-02-15

    This book is comprised of nineteen chapters, which describes introduction of analytical chemistry, experimental error and statistics, chemistry equilibrium and solubility, gravimetric analysis with mechanism of precipitation, range and calculation of the result, volume analysis on general principle, sedimentation method on types and titration curve, acid base balance, acid base titration curve, complex and firing reaction, introduction of chemical electro analysis, acid-base titration curve, electrode and potentiometry, electrolysis and conductometry, voltammetry and polarographic spectrophotometry, atomic spectrometry, solvent extraction, chromatograph and experiments.

  3. Analytical chemistry

    International Nuclear Information System (INIS)

    Choi, Jae Seong

    1993-02-01

    This book is comprised of nineteen chapters, which describes introduction of analytical chemistry, experimental error and statistics, chemistry equilibrium and solubility, gravimetric analysis with mechanism of precipitation, range and calculation of the result, volume analysis on general principle, sedimentation method on types and titration curve, acid base balance, acid base titration curve, complex and firing reaction, introduction of chemical electro analysis, acid-base titration curve, electrode and potentiometry, electrolysis and conductometry, voltammetry and polarographic spectrophotometry, atomic spectrometry, solvent extraction, chromatograph and experiments.

  4. Analytical chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Chae, Myeong Hu; Lee, Hu Jun; Kim, Ha Seok

    1989-02-15

    This book give explanations on analytical chemistry with ten chapters, which deal with development of analytical chemistry, the theory of error with definition and classification, sample and treatment gravimetry on general process of gravimetry in aqueous solution and non-aqueous solution, precipitation titration about precipitation reaction and types, complexometry with summary and complex compound, oxidation-reduction equilibrium on electrode potential and potentiometric titration, solvent extraction and chromatograph and experiment with basic operation for chemical experiment.

  5. Analytical chemistry

    International Nuclear Information System (INIS)

    Chae, Myeong Hu; Lee, Hu Jun; Kim, Ha Seok

    1989-02-01

    This book give explanations on analytical chemistry with ten chapters, which deal with development of analytical chemistry, the theory of error with definition and classification, sample and treatment gravimetry on general process of gravimetry in aqueous solution and non-aqueous solution, precipitation titration about precipitation reaction and types, complexometry with summary and complex compound, oxidation-reduction equilibrium on electrode potential and potentiometric titration, solvent extraction and chromatograph and experiment with basic operation for chemical experiment.

  6. Green Chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Collison, Melanie

    2011-05-15

    Green chemistry is the science of chemistry used in a way that will not use or create hazardous substances. Dr. Rui Resendes is working in this field at GreenCentre Canada, an offshoot of PARTEQ Innovations in Kingston, Ontario. GreenCentre's preliminary findings suggest their licensed product {sup S}witchable Solutions{sup ,} featuring 3 classes of solvents and a surfactant, may be useful in bitumen oil sands extraction.

  7. Carbon footprint reductions via grid energy storage systems

    Energy Technology Data Exchange (ETDEWEB)

    Hale, Trevor S. [Naval Facilities Engineering Service Center, 1100 23rd Avenue, Port Huenem, CA 93043 (United States); Department of Management, Marketing, and Business Administration, University of Houston - Downtown, Houston, Texas (United States); Weeks, Kelly [Department of Maritime Administration, Texas A and M University at Galveston, Galveston, TX 77553 (United States); Tucker, Coleman [Department of Management, Marketing, and Business Administration, University of Houston - Downtown, Houston, Texas 77002 (United States)

    2011-07-01

    This effort presents a framework for reducing carbon emissions through the use of large-scale grid-energy-storage (GES) systems. The specific questions under investigation herein are as follows: Is it economically sound to invest in a GES system and is the system at least carbon footprint neutral? This research will show the answer to both questions is in the affirmative. Scilicet, when utilized judiciously, grid energy storage systems can be both net present value positive as well as be total carbon footprint negative. The significant contribution herein is a necessary and sufficient condition for achieving carbon footprint reductions via grid energy storage systems.

  8. Potentials and limitations of footprints for gauging environmental sustainability

    DEFF Research Database (Denmark)

    Laurent, Alexis; Owsianiak, Mikolaj

    2017-01-01

    To address the sustainability challenge, a large variety of footprints, aiming at capturing specific impacts of human activities on natural environment, have emerged. But, how do they fit into our addressing of environmental sustainability? Here, we build on a critical literature review to (1......) provide an overview of existing footprints; (2) define their roles; (3) position them within the broad spectrum of known environmental problems and control variables of the planetary boundaries; and (4) argue for the need of consistent thresholds to benchmark footprint scores against absolute...

  9. Progress on Footprint Reduction at the Hanford Site - 12406

    Energy Technology Data Exchange (ETDEWEB)

    McKenney, Dale E. [CH2M HILL, Plateau Remediation Company, Richland, Washington 99352 (United States); Seeley, Paul [Cenibark International, Inc., Richland, Washington 99352 (United States); Farabee, Al [U.S. Department of Energy, Richland Operations Office, Richland, Washington 99352 (United States)

    2012-07-01

    The Department of Energy (DOE) Office of Environmental Management (EM) continues to reduce the footprint of legacy sites throughout the EM complex. Footprint reduction is being accomplished by focusing cleanup activities on decontamination and demolition of excess contaminated facilities, soil and groundwater remediation, and solid waste disposition. All of these initiatives are being accomplished with established technologies in proven regulatory frameworks. Ultimately, completion of these environmental cleanup activities will reduce the monitoring and maintenance costs associated with managing large federal facilities, allowing EM to place more focus on other high priority cleanup efforts and facilitate a successful transition to land-term stewardship of these sites. Through the American Recovery and Reinvestment Act (ARRA) investment, the Department's cleanup footprint has been reduced by 45 percent to date, from 2411 km{sup 2} (931 mi{sup 2}) to 1336 km{sup 2} (516 mi{sup 2}s). With this significant progress on footprint reduction, the Department is on track towards their goal to reduce its overall footprint by approximately 90 percent by 2015. In addition, some areas cleaned up may become available for alternate uses (i.e. recreation, conservation, preservation, industrialization or development). Much of the work to reduce the complex's footprint occurred at the Savannah River Site in South Carolina and the Hanford Site in Washington, but cleanup continues across the complex. Footprint reduction is progressing well at the Hanford Site, supported predominantly through ARRA investment. To date, 994 km{sup 2} (384 mi{sup 2}) (65%) of footprint reduction have been achieved at Hanford, with a goal to achieve a 90% reduction by Fiscal Year 2015. The DOE EM and DOE Richland Operations Office, continue to make great progress to reduce the legacy footprint of the Hanford Site. Footprint reduction is being accomplished by focusing cleanup activities on

  10. UV-POSIT: Web-Based Tools for Rapid and Facile Structural Interpretation of Ultraviolet Photodissociation (UVPD) Mass Spectra

    Science.gov (United States)

    Rosenberg, Jake; Parker, W. Ryan; Cammarata, Michael B.; Brodbelt, Jennifer S.

    2018-04-01

    UV-POSIT (Ultraviolet Photodissociation Online Structure Interrogation Tools) is a suite of web-based tools designed to facilitate the rapid interpretation of data from native mass spectrometry experiments making use of 193 nm ultraviolet photodissociation (UVPD). The suite includes four separate utilities which assist in the calculation of fragment ion abundances as a function of backbone cleavage sites and sequence position; the localization of charge sites in intact proteins; the calculation of hydrogen elimination propensity for a-type fragment ions; and mass-offset searching of UVPD spectra to identify unknown modifications and assess false positive fragment identifications. UV-POSIT is implemented as a Python/Flask web application hosted at http://uv-posit.cm.utexas.edu. UV-POSIT is available under the MIT license, and the source code is available at https://github.com/jarosenb/UV_POSIT. [Figure not available: see fulltext.

  11. Active vs. spectator modes in nonadiabatic photodissociation dynamics of the hydroxymethyl radical via the 22A(3s) Rydberg state

    Science.gov (United States)

    Xie, Changjian; Guo, Hua

    2018-01-01

    The choice of the active degrees of freedom (DOFs) is a pivotal issue in a reduced-dimensional model of quantum dynamics when a full-dimensional one is not feasible. Here, several five-dimensional (5D) models are used to investigate the nonadiabatic photodissociation dynamics of the hydroxymethyl (CH2OH) radical, which possesses nine internal DOFs, in its lowest absorption band. A normal-mode based scheme is used to identify the active and spectator modes, and its predictions are confirmed by 5D quantum dynamical calculations. Our results underscore the important role of the CO stretching mode in the photodissociation dynamics of CH2OH, originating from the photo-induced promotion of an electron from the half-occupied π*CO antibonding orbital to a carbon Rydberg orbital.

  12. UV-POSIT: Web-Based Tools for Rapid and Facile Structural Interpretation of Ultraviolet Photodissociation (UVPD) Mass Spectra.

    Science.gov (United States)

    Rosenberg, Jake; Parker, W Ryan; Cammarata, Michael B; Brodbelt, Jennifer S

    2018-04-06

    UV-POSIT (Ultraviolet Photodissociation Online Structure Interrogation Tools) is a suite of web-based tools designed to facilitate the rapid interpretation of data from native mass spectrometry experiments making use of 193 nm ultraviolet photodissociation (UVPD). The suite includes four separate utilities which assist in the calculation of fragment ion abundances as a function of backbone cleavage sites and sequence position; the localization of charge sites in intact proteins; the calculation of hydrogen elimination propensity for a-type fragment ions; and mass-offset searching of UVPD spectra to identify unknown modifications and assess false positive fragment identifications. UV-POSIT is implemented as a Python/Flask web application hosted at http://uv-posit.cm.utexas.edu . UV-POSIT is available under the MIT license, and the source code is available at https://github.com/jarosenb/UV_POSIT . Graphical Abstract.

  13. Optimal laser control of ultrafast photodissociation of I2- in water: Mixed quantum/classical molecular dynamics simulation

    International Nuclear Information System (INIS)

    Nishiyama, Yoshikazu; Kato, Tsuyoshi; Ohtsuki, Yukiyoshi; Fujimura, Yuichi

    2004-01-01

    A linearized optimal control method in combination with mixed quantum/classical molecular dynamics simulation is used for numerically investigating the possibility of controlling photodissociation wave packets of I 2 - in water. Optimal pulses are designed using an ensemble of photodissociation samples, aiming at the creation of localized dissociation wave packets. Numerical results clearly show the effectiveness of the control although the control achievement is reduced with an increase in the internuclear distance associated with a target region. We introduce effective optimal pulses that are designed using a statistically averaged effective dissociation potential, and show that they semiquantitatively reproduce the control achievements calculated by using optimal pulses. The control mechanisms are interpreted from the time- and frequency-resolved spectra of the effective optimal pulses

  14. Photodissociation of H2+ by intense chirped pulses - beyond the effect of pulse duration and peak power

    International Nuclear Information System (INIS)

    Lev, U; Prabhudesai, V; Natan, A; Bruner, B; Diner, A; Heber, O; Strasser, D; Schwalm, D; Silberberg, Y; Zajfman, D; Ben-Itzhak, I; Hua, J J; Esry, B D

    2009-01-01

    H 2 + photodissociation, induced by intense short laser pulses, was measured by a full 3D imaging system. We have conducted a series of experiments, in which we systematically changed the linear chirp, using a pulse shaper, and observed the kinetic energy release spectra(KER). Distinct differences in the KER spectra are observed both in peak positions and angular distribution for laser pulses with similar duration and intensity but opposite chirp sign.

  15. Photodissociation of H{sub 2}{sup +} by intense chirped pulses - beyond the effect of pulse duration and peak power

    Energy Technology Data Exchange (ETDEWEB)

    Lev, U; Prabhudesai, V; Natan, A; Bruner, B; Diner, A; Heber, O; Strasser, D; Schwalm, D; Silberberg, Y; Zajfman, D [Faculty of Physics, Weizmann Institute of Science, Rehovot 76100 (Israel); Ben-Itzhak, I; Hua, J J; Esry, B D, E-mail: uri.lev@Weizmann.ac.i [Department of Physics, Kansas State University, Manhattan, KS 66506 (United States)

    2009-11-01

    H{sub 2}{sup +} photodissociation, induced by intense short laser pulses, was measured by a full 3D imaging system. We have conducted a series of experiments, in which we systematically changed the linear chirp, using a pulse shaper, and observed the kinetic energy release spectra(KER). Distinct differences in the KER spectra are observed both in peak positions and angular distribution for laser pulses with similar duration and intensity but opposite chirp sign.

  16. Study of the photodissociation of a CdSe nanocrystal beam by means of photoluminescence and Raman scattering

    CERN Document Server

    Orii, T; Onari, S; Kaito, S I; Arai, T

    1997-01-01

    We developed an apparatus that enables us to perform optical measurements of nanocrystals suspended in vacuum. CdSe nanocrystals were produced by a gas evaporation method, and nanocrystal beams were then formed using an inert-gas flow with differential pumping. We measured photoluminescence spectra of the nanocrystal beams with excitations of various photon energies and powers. For a low excitation power, edge emission of the CdSe nanocrystal beam was observed. With increase of the laser power, Raman lines of Se dimers emitted due to the photodissociation of CdSe nanocrystals were observed. It was found that the thresholds of the excitation laser fluence for the photodissociation of CdSe nanocrystals were much smaller than the thresholds of laser fluence for the laser-induced emission of Se atoms from bulk CdSe. The electronic process is dominant in the photodissociation of CdSe nanocrystals whose surfaces are completely free. We suggest that the effective supply of carriers confined in nanocrystals to the su...

  17. Small Footprint Solar/Wind-powered CASTNET System Dataset

    Data.gov (United States)

    U.S. Environmental Protection Agency — In this Research Effort “Small Footprint Solar/Wind-Powered CASTNET System” there are two data sets. One data set contains atmospheric concentration measurements, at...

  18. Application of the DIY carbon footprint calculator to a wastewater ...

    African Journals Online (AJOL)

    In order to manage the energy budget and develop climate-friendly technological ... step involves the development of strategies to reduce the carbon footprint. ..... Intelligent management systems: aeration of the activated sludge process.

  19. Cooperative water network system to reduce carbon footprint.

    Science.gov (United States)

    Lim, Seong-Rin; Park, Jong Moon

    2008-08-15

    Much effort has been made in reducing the carbon footprint to mitigate climate change. However, water network synthesis has been focused on reducing the consumption and cost of freshwater within each industrial plant. The objective of this study is to illustrate the necessity of the cooperation of industrial plants to reduce the total carbon footprint of their water supply systems. A mathematical optimization model to minimize global warming potentials is developed to synthesize (1) a cooperative water network system (WNS) integrated over two plants and (2) an individual WNS consisting of two WNSs separated for each plant. The cooperative WNS is compared to the individual WNS. The cooperation reduces their carbon footprint and is economically feasible and profitable. A strategy for implementing the cooperation is suggested for the fair distribution of costs and benefits. As a consequence, industrial plants should cooperate with their neighbor plants to further reduce the carbon footprint.

  20. relationship between climatic variability and water footprint of ...

    African Journals Online (AJOL)

    Global Journal

    Blue water footprint (WFblue) value calculated as 172/m2/ton was found to be higher ... There are earth system interactions of atmosphere ... warmer earth, rising from the fact that global .... of soil is structurally sticky, with colours between dark.

  1. Spatially Explicit Analysis of Water Footprints in the UK

    Directory of Open Access Journals (Sweden)

    John Barrett

    2010-12-01

    Full Text Available The Water Footprint, as an indicator of water consumption has become increasingly popular for analyzing environmental issues associated with the use of water resources in the global supply chain of consumer goods. This is particularly relevant for countries like the UK, which increasingly rely on products produced elsewhere in the world and thus impose pressures on foreign water resources. Existing studies calculating water footprints are mostly based on process analysis, and results are mainly available at the national level. The current paper assesses the domestic and foreign water requirements for UK final consumption by applying an environmentally extended multi-regional input-output model in combination with geo-demographic consumer segmentation data. This approach allows us to calculate water footprints (both direct and indirect for different products as well as different geographies within the UK. We distinguished between production and consumption footprints where the former is the total water consumed from the UK domestic water resources by the production activities in the UK and the latter is the total water consumed from both domestic and global water resources to satisfy the UK domestic final consumption. The results show that the production water footprint is 439 m3/cap/year, 85% of which is for the final consumption in the UK itself. The average consumption water footprint of the UK is more than three times bigger than the UK production water footprint in 2006. About half of the UK consumption water footprints were associated with imports from Non-OECD countries (many of which are water-scarce, while around 19% were from EU-OECD countries, and only 3% from Non-EU-OECD countries. We find that the water footprint differs considerably across sub-national geographies in the UK, and the differences are as big as 273 m3/cap/year for the internal water footprint and 802 m3/cap/year for the external water footprint. Our results suggest

  2. Does footprint depth correlate with foot motion and pressure?

    OpenAIRE

    Bates, K. T.; Savage, R.; Pataky, T. C.; Morse, S. A.; Webster, E.; Falkingham, P. L.; Ren, L.; Qian, Z.; Collins, D.; Bennett, M. R.; McClymont, J.; Crompton, R. H.

    2013-01-01

    Footprints are the most direct source of evidence about locomotor biomechanics in extinct vertebrates. One of the principal suppositions underpinning biomechanical inferences is that footprint geometry correlates with dynamic foot pressure, which, in turn, is linked with overall limb motion of the trackmaker. In this study, we perform the first quantitative test of this long-standing assumption, using topological statistical analysis of plantar pressures and experimental and computer-simulate...

  3. Assessment of global grey water footprint of major food crops

    Science.gov (United States)

    Yang, Hong; Liu, Wenfeng; Antonelli, Marta

    2016-04-01

    Agricultural production is one of the major sources of water pollution in the world. This is closely related to the excess application of fertilizers. Leaching of N and P to water bodies has caused serious degradation of water quality in many places. With the persistent increase in the demand for agricultural products, agricultural intensification evident during the past decades will continue in the future. This will lead to further increase in fertilizer application and consequently water pollution. Grey water footprint is a measure of the intensity of water pollution caused by water use for human activities. It is defined as the volume of water that is required to assimilate a load of pollutants to a freshwater body, based on natural background concentrations and water quality standards. This study conducts a global assessment of grey water footprint for major cereal crops, wheat, maize and rice. A crop model, Python-based EPIC (PEPIT), is applied to quantify the leaching of N and P from the fertilizer application in the three crops on a global scale with 0.5 degree spatial resolution. The hotspots of leaching are identified. The results suggest that, based on the definition and method of grey water footprint proposed by the World Water Footprint Network, the grey water footprint in many parts of the world has exceeded their total water resources availability. This indicates the seriousness of water pollution caused by agricultural production. However, the situation may also call for the development of a realistic measurement of grey water footprint which is more pertinent to water resources management. This paper proposes some alternatives in measuring grey water footprint and also discusses incorporation of grey water footprint assessment into water policy formulation and river basins plan development.

  4. Water Footprint and Virtual Water Trade of Brazil

    OpenAIRE

    da Silva, Vicente de Paulo R.; de Oliveira, Sonaly D.; Hoekstra, Arjen Ysbert; Neto, Jose Dantas; Campos, João Hugo B.C.; Braga, Celia C.; Araújo, Lincoln Eloi; Oliveira Aleixo, Danilo; de Brito, Jose Ivaldo B.; de Souza, Marcio Dionisio; de Holanda, Romildo M.

    2016-01-01

    Freshwater scarcity has increased at an alarming rate worldwide; improved water management plays a vital role in increasing food production and security. This study aims to determine the water footprint of Brazil’s national food consumption, the virtual water flows associated with international trade in the main agricultural commodities, as well as water scarcity, water self-sufficiency and water dependency per Brazilian region. While previous country studies on water footprints and virtual w...

  5. The blue water footprint of electricity from hydropower

    Directory of Open Access Journals (Sweden)

    M. M. Mekonnen

    2012-01-01

    Full Text Available Hydropower accounts for about 16% of the world's electricity supply. It has been debated whether hydroelectric generation is merely an in-stream water user or whether it also consumes water. In this paper we provide scientific support for the argument that hydroelectric generation is in most cases a significant water consumer. The study assesses the blue water footprint of hydroelectricity – the water evaporated from manmade reservoirs to produce electric energy – for 35 selected sites. The aggregated blue water footprint of the selected hydropower plants is 90 Gm3 yr−1, which is equivalent to 10% of the blue water footprint of global crop production in the year 2000. The total blue water footprint of hydroelectric generation in the world must be considerably larger if one considers the fact that this study covers only 8% of the global installed hydroelectric capacity. Hydroelectric generation is thus a significant water consumer. The average water footprint of the selected hydropower plants is 68 m3 GJ−1. Great differences in water footprint among hydropower plants exist, due to differences in climate in the places where the plants are situated, but more importantly as a result of large differences in the area flooded per unit of installed hydroelectric capacity. We recommend that water footprint assessment is added as a component in evaluations of newly proposed hydropower plants as well as in the evaluation of existing hydroelectric dams, so that the consequences of the water footprint of hydroelectric generation on downstream environmental flows and other water users can be evaluated.

  6. Nonadiabatic effects in C-Br bond scission in the photodissociation of bromoacetyl chloride

    International Nuclear Information System (INIS)

    Valero, Rosendo; Truhlar, Donald G.

    2006-01-01

    Bromoacetyl chloride photodissociation has been interpreted as a paradigmatic example of a process in which nonadiabatic effects play a major role. In molecular beam experiments by Butler and co-workers [J. Chem. Phys. 95, 3848 (1991); J. Chem. Phys. 97, 355 (1992)], BrCH 2 C(O)Cl was prepared in its ground electronic state (S 0 ) and excited with a laser at 248 nm to its first excited singlet state (S 1 ). The two main ensuing photoreactions are the ruptures of the C-Cl bond and of the C-Br bond. A nonadiabatic model was proposed in which the C-Br scission is strongly suppressed due to nonadiabatic recrossing at the barrier formed by the avoided crossing between the S 1 and S 2 states. Recent reduced-dimensional dynamical studies lend support to this model. However, another interpretation that has been given for the experimental results is that the reduced probability of C-Br scission is a consequence of incomplete intramolecular energy redistribution. To provide further insight into this problem, we have studied the energetically lowest six singlet electronic states of bromoacetyl chloride by using an ab initio multiconfigurational perturbative electronic structure method. Stationary points (minima and saddle points) and minimum energy paths have been characterized on the S 0 and S 1 potential energy surfaces. The fourfold way diabatization method has been applied to transform five adiabatic excited electronic states to a diabatic representation. The diabatic potential energy matrix of the first five excited singlet states has been constructed along several cuts of the potential energy hypersurfaces. The thermochemistry of the photodissociation reactions and a comparison with experimental translational energy distributions strongly suggest that nonadiabatic effects dominate the C-Br scission, but that the reaction proceeds along the energetically allowed diabatic pathway to excited-state products instead of being nonadiabatically suppressed. This conclusion is

  7. Environmental footprint of constructed wetlands treating wastewater.

    Science.gov (United States)

    Gkika, Dimitra; Gikas, Georgios D; Tsihrintzis, Vassilios A

    2015-01-01

    The aim of the study is to determine environmentally friendlier construction materials for constructed wetland facilities treating wastewater. This is done by computing the environmental footprint of the facility based on the methodology of life cycle assessment (LCA). This methodology reveals the dominant aggravating processes during the construction of a constructed wetland (CW) and can help to create alternative environmentally friendlier solutions. This methodology was applied for the determination of the overall environmental profile of a hybrid CW facility. The LCA was applied first to the facility as originally designed, where reinforced concrete was used in some components. Then, alternative construction materials to reinforced concrete were used, such as earth covered with high density polyethylene (HDPE) or clay, and LCA was applied again. Earth structures were found to have reduced environmental impact compared to concrete ones, and clay was found environmentally friendlier compared to HDPE. Furthermore, estimation of the construction costs of the three scenarios indicate that the last scenario is also the least expensive.

  8. Mealworms for Food: A Water Footprint Perspective

    Directory of Open Access Journals (Sweden)

    Pier Paolo Miglietta

    2015-11-01

    Full Text Available In this paper, we have explored the possibility of substituting traditional meat products with an alternative source of protein (insects in order to reduce human pressure on water. Insects, in fact, could represent a good alternative source of quality proteins and nutrients and they are already a very popular component of the diet of one third of the world’s population in approximately 80% of countries. In the study, we have taken into account only two species of edible insects (Tenebrio molitor and Zophobas morio mealworms, because they are already commercially produced even in Western countries, and for this reason it is possible to find specific data in literature about their diets. We have used the water footprint (WF as a reliable indicator to calculate the volume of water required for production and to compare different products. The final aim of the work is, in fact, to evaluate the WF of the production of edible insects with a focus on water consumption associated with protein content, in order to make a comparison with other animal protein sources. We have demonstrated that, from a freshwater resource perspective, it is more efficient to obtain protein through mealworms rather than other traditional farmed animals.

  9. Conformal polishing approach: Tool footprint analysis

    Directory of Open Access Journals (Sweden)

    José A Dieste

    2016-02-01

    Full Text Available Polishing process is one of the most critical manufacturing processes during a metal part production because it determines the final quality of the product. Free-form surface polishing is a handmade process with lots of rejected parts, scrap generation and time and energy consumption. Two different research lines are being developed: prediction models of the final surface quality parameters and an analysis of the amount of material removed depending on the polishing parameters to predict the tool footprint during the polishing task. This research lays the foundations for a future automatic conformal polishing system. It is based on rotational and translational tool with dry abrasive in the front mounted at the end of a robot. A tool to part concept is used, useful for large or heavy workpieces. Results are applied on different curved parts typically used in tooling industry, aeronautics or automotive. A mathematical model has been developed to predict the amount of material removed in function of polishing parameters. Model has been fitted for different abrasives and raw materials. Results have shown deviations under 20% that implies a reliable and controllable process. Smaller amount of material can be removed in controlled areas of a three-dimensional workpiece.

  10. The Water Footprint of Data Centers

    Directory of Open Access Journals (Sweden)

    Bora Ristic

    2015-08-01

    Full Text Available The internet and associated Information and Communications Technologies (ICT are diffusing at an astounding pace. As data centers (DCs proliferate to accommodate this rising demand, their environmental impacts grow too. While the energy efficiency of DCs has been researched extensively, their water footprint (WF has so far received little to no attention. This article conducts a preliminary WF accounting for cooling and energy consumption in DCs. The WF of DCs is estimated to be between 1047 and 151,061 m3/TJ. Outbound DC data traffic generates a WF of 1–205 liters per gigabyte (roughly equal to the WF of 1 kg of tomatos at the higher end. It is found that, typically, energy consumption constitues by far the greatest share of DC WF, but the level of uncertainty associated with the WF of different energy sources used by DCs makes a comprehensive assessment of DCs’ water use efficiency very challenging. Much better understanding of DC WF is urgently needed if a meaningful evaluation of this rapidly spreading service technology is to be gleaned and response measures are to be put into effect.

  11. Low Carbon Footprint Routes for Bird Watching

    Directory of Open Access Journals (Sweden)

    Wei-Ta Fang

    2015-03-01

    Full Text Available Bird watching is one of many recreational activities popular in ecotourism. Its popularity, therefore, prompts the need for studies on energy conservation. One such environmentally friendly approach toward minimizing bird watching’s ecological impact is ensuring a reduced carbon footprint by using an economic travel itinerary comprising a series of connected routes between tourist attractions that minimizes transit time. This study used a travel-route planning approach using geographic information systems to detect the shortest path, thereby solving the problems associated with time-consuming transport. Based on the results of road network analyses, optimal travel-route planning can be determined. These methods include simulated annealing (SA and genetic algorithms (GA. We applied two algorithms in our simulation research to detect which one is an appropriate algorithm for running carbon-routing algorithms at the regional scale. SA, which is superior to GA, is considered an excellent approach to search for the optimal path to reduce carbon dioxide and high gasoline fees, thereby controlling travel time by using the shortest travel routes.

  12. Carbon Footprint Linked to transport infrastructures

    International Nuclear Information System (INIS)

    Crespo Garcia, L.; Jimenez Arroyo, F.

    2013-01-01

    Quantification of emissions of greenhouse effect gases associated to transport infrastructures has been addressed in different ways. The first tools for this purpose appeared with the application of ISO 14040 standards (Life cycle analysis) that, applied to the particular case of energetic resources, led to a new concept known as carbon footprint. There is a specific standard for this quantification (ISO 14064) according to which, for the case of infrastructures, emissions and environmental effects linked to the whole life cycle are assessed taking into account all the stages: building, exploitation, maintenance and dismantling. the key point to perform this analysis is the accurate definition of a calculation methodology to be applied to the inventory of activities covered, in order to avoid information lacks, overlaps or redundancies. Quantification tools for emissions are effectively a reality, but social and political will, supported by strong economical reasons recognizing energy as a vital resource, is necessary for these tools to be developed, enhanced and used in a systematic way as a key decision element to choice among different transport alternatives. (Author) 23 refs.

  13. Dealing with uncertainty in water scarcity footprints

    Science.gov (United States)

    Scherer, Laura; Pfister, Stephan

    2016-05-01

    Water scarcity adversely affects ecosystems, human well-being and the economy. It can be described by water scarcity indices (WSIs) which we calculated globally for the decades 1981-1990 and 2001-2010. Based on a model ensemble, we calculated the WSI for both decades including uncertainties. While there is a slight tendency of increased water scarcity in 2001-2010, the likelihood of the increase is rather low (53%). Climate change played only a minor role, but increased water consumption is more decisive. In the last decade, a large share of the global population already lived under highly water scarce conditions with a global average monthly WSI of 0.51 (on a scale from 0 to 1). Considering that globally there are enough water resources to satisfy all our needs, this highlights the need for regional optimization of water consumption. In addition, crop choices within a food group can help reduce humanity’s water scarcity footprint without reducing its nutritional value.

  14. Understanding the LCA and ISO water footprint: A response to ...

    Science.gov (United States)

    Water footprinting has emerged as an important approach to assess water use related effects from consumption of goods and services. Assessment methods are proposed by two different communities, the Water Footprint Network (WFN) and the Life Cycle Assessment (LCA) community. The proposed methods are broadly similar and encompass both the computation of water use and its impacts, but differ in communication of a water footprint result. In this paper, we explain the role and goal of LCA and ISO-compatible water footprinting and resolve the six issues raised by Hoekstra (2016) in “A critique on the water-scarcity weighted water footprint in LCA”. By clarifying the concerns, we identify both the overlapping goals in the WFN and LCA water footprint assessments and discrepancies between them. The main differing perspective between the WFN and LCA-based approach seems to relate to the fact that LCA aims to account for environmental impacts, while the WFN aims to account for water productivity of global fresh water as a limited resource. We conclude that there is potential to use synergies in research for the two approaches and highlight the need for proper declaration of the methods applied. This paper advances efforts to understand ways to accurately capture use of water in life cycle analysis in other contexts. As the paper indicates, there is a discussion about whether quantities of water should be weighted by some local stress factor. This paper attempts to brid

  15. General chemistry

    International Nuclear Information System (INIS)

    Kwon, Yeong Sik; Lee, Dong Seop; Ryu, Haung Ryong; Jang, Cheol Hyeon; Choi, Bong Jong; Choi, Sang Won

    1993-07-01

    The book concentrates on the latest general chemistry, which is divided int twenty-three chapters. It deals with basic conception and stoichiometry, nature of gas, structure of atoms, quantum mechanics, symbol and structure of an electron of ion and molecule, chemical thermodynamics, nature of solid, change of state and liquid, properties of solution, chemical equilibrium, solution and acid-base, equilibrium of aqueous solution, electrochemistry, chemical reaction speed, molecule spectroscopy, hydrogen, oxygen and water, metallic atom; 1A, IIA, IIIA, carbon and atom IVA, nonmetal atom and an inert gas, transition metals, lanthanons, and actinoids, nuclear properties and radioactivity, biochemistry and environment chemistry.

  16. Radiation chemistry

    International Nuclear Information System (INIS)

    Swallow, A.J.

    1983-01-01

    The subject is covered in chapters, entitled: introduction (defines scope of article as dealing with the chemistry of reactive species, (e.g. excess electrons, excited states, free radicals and inorganic ions in unusual valency states) as studied using radiation with radiation chemistry in its traditional sense and with biological and industrial applications); gases; water and simple inorganic systems; aqueous metallo-organic compounds and metalloproteins; small organic molecules in aqueous solution; microheterogeneous systems; non-aqueous liquids and solutions; solids; biological macromolecules; synthetic polymers. (U.K.)

  17. Indoor Chemistry

    DEFF Research Database (Denmark)

    Weschler, Charles J.; Carslaw, Nicola

    2018-01-01

    This review aims to encapsulate the importance, ubiquity, and complexity of indoor chemistry. We discuss the many sources of indoor air pollutants and summarize their chemical reactions in the air and on surfaces. We also summarize some of the known impacts of human occupants, who act as sources...... and sinks of indoor chemicals, and whose activities (e.g., cooking, cleaning, smoking) can lead to extremely high pollutant concentrations. As we begin to use increasingly sensitive and selective instrumentation indoors, we are learning more about chemistry in this relatively understudied environment....

  18. Handbook of heterocyclic chemistry

    National Research Council Canada - National Science Library

    Katritzky, Alan R

    2010-01-01

    ... Heterocyclic Chemistry I (1984) Comprehensive Heterocyclic Chemistry II (1996) Comprehensive Heterocyclic Chemistry III (2008) Comprehensive Organic Functional Group Transformations I (1995) Compreh...

  19. The carbon footprint of an Australian satellite haemodialysis unit.

    Science.gov (United States)

    Lim, Allan E K; Perkins, Anthony; Agar, John W M

    2013-06-01

    This study aimed to better understand the carbon emission impact of haemodialysis (HD) throughout Australia by determining its carbon footprint, the relative contributions of various sectors to this footprint, and how contributions from electricity and water consumption are affected by local factors. Activity data associated with HD provision at a 6-chair suburban satellite HD unit in Victoria in 2011 was collected and converted to a common measurement unit of tonnes of CO2 equivalents (t CO2-eq) via established emissions factors. For electricity and water consumption, emissions factors for other Australian locations were applied to assess the impact of local factors on these footprint contributors. In Victoria, the annual per-patient carbon footprint of satellite HD was calculated to be 10.2t CO2-eq. The largest contributors were pharmaceuticals (35.7%) and medical equipment (23.4%). Throughout Australia, the emissions percentage attributable to electricity consumption ranged from 5.2% to 18.6%, while the emissions percentage attributable to water use ranged from 4.0% to 11.6%. State-by-state contributions of energy and water use to the carbon footprint of satellite HD appear to vary significantly. Performing emissions planning and target setting at the state level may be more appropriate in the Australian context. What is known about the topic? Healthcare provision carries a significant environmental footprint. In particular, conventional HD uses substantial amounts of electricity and water. In the UK, provision of HD and peritoneal dialysis was found to have an annual per-patient carbon footprint of 7.1t CO2-eq. What does this paper add? This is the first carbon-footprinting study of HD in Australia. In Victoria, the annual per-patient carbon footprint of satellite conventional HD is 10.2t CO2-eq. Notably, the contributions of electricity and water consumption to the carbon footprint varies significantly throughout Australia when local factors are taken into

  20. Improved production of Br atoms near zero speed by photodissociating laser aligned Br2 molecules.

    Science.gov (United States)

    Deng, L Z; Yin, J P

    2014-10-28

    We theoretically investigated the improvement on the production rate of the decelerated bromine (Br) atoms near zero speed by photodissociating laser aligned Br2 precursors. Adiabatic alignment of Br2 precursors exposed to long laser pulses with duration on the order of nanoseconds was investigated by solving the time-dependent Schrödinger equation. The dynamical fragmentation of adiabatically aligned Br2 precursors was simulated and velocity distribution of the Br atoms produced was analyzed. Our study shows that the larger the degree of the precursor alignment, ⟨cos(2) θ⟩, the higher the production rate of the decelerated Br atoms near zero speed. For Br2 molecules with an initial rotational temperature of ~1 K, a ⟨cos(2) θ⟩ value of ~0.88 can result in an improvement factor of over ~20 on the production rate of the decelerated Br atoms near zero speed, requiring a laser intensity of only ~1 × 10(12) W/cm(2) for alignment.

  1. Imaging the Dynamics of CH2BrI Photodissociation in the Near Ultraviolet Region.

    Science.gov (United States)

    Pan, Changen; Zhang, Yi; Lee, Joseph D; Kidwell, Nathanael M

    2018-04-19

    The photodissociation dynamics of jet-cooled CH 2 BrI were investigated in the near-ultraviolet (UV) region from 280-310 nm using velocity map imaging. We report the translational and internal energy distributions of the CH 2 Br radical and ground state I ( 2 P 3/2 ) or spin-orbit excited I ( 2 P 1/2 ) fragments determined by velocity map imaging of the ionized iodine fragments following 2 + 1 resonance-enhanced multiphoton ionization of the nascent neutral iodine products. The velocity distributions indicate that most of the available energy is partitioned into the internal energy of the CH 2 Br radical with only modest translational excitation imparted to the cofragments, which is consistent with a simple impulsive model. Furthermore, from extrapolation of the velocity distribution results, the first determination of the C-I bond dissociation energy of CH 2 BrI is presented in this work to be D 0 = 16 790 ± 590 cm -1 . The ion images appear anisotropic, indicative of a prompt dissociation, and the derived anisotropy parameters are consistently positive. Additionally, the angular distributions report on the electronic excited state dynamics, which validate recent works characterizing the electronic states responsible for the first absorption band of CH 2 BrI. In the current work, photolysis of CH 2 BrI on the red edge of the absorption spectrum reveals an additional channel producing I ( 2 P 3/2 ) fragments.

  2. Photodissociation of anisole and absolute photoionization cross-section of the phenoxy radical.

    Science.gov (United States)

    Xu, Hong; Pratt, S T

    2013-11-21

    We have studied the photodissociation dynamics of anisole (C6H5OCH3) at 193 nm and determined the absolute photoionization cross-section of the phenoxy radical at 118.2 nm (10.486 eV) relative to the known cross-section of the methyl radical. Even at this energy, there is extensive fragmentation of the phenoxy radical upon photoionization, which is attributed to ionizing transitions that populate low-lying excited electronic states of the cation. For phenoxy radicals with less than ∼1 eV of internal energy, we find a cross-section for the production of the phenoxy cation of 14.8 ± 3.8 Mb. For radicals with higher internal energy, dissociative ionization is the dominant process, and for internal energies of ∼2.7-3.7 eV, we find a total cross-section (photoionization plus dissociative ionization) of 22.3 ± 4.1 Mb. The results are discussed relative to the recently reported photoionization cross-section of phenol.

  3. Characterization of hydrogen bonding motifs in proteins: hydrogen elimination monitoring by ultraviolet photodissociation mass spectrometry.

    Science.gov (United States)

    Morrison, Lindsay J; Chai, Wenrui; Rosenberg, Jake A; Henkelman, Graeme; Brodbelt, Jennifer S

    2017-08-02

    Determination of structure and folding of certain classes of proteins remains intractable by conventional structural characterization strategies and has spurred the development of alternative methodologies. Mass spectrometry-based approaches have a unique capacity to differentiate protein heterogeneity due to the ability to discriminate populations, whether minor or major, featuring modifications or complexation with non-covalent ligands on the basis of m/z. Cleavage of the peptide backbone can be further utilized to obtain residue-specific structural information. Here, hydrogen elimination monitoring (HEM) upon ultraviolet photodissociation (UVPD) of proteins transferred to the gas phase via nativespray ionization is introduced as an innovative approach to deduce backbone hydrogen bonding patterns. Using well-characterized peptides and a series of proteins, prediction of the engagement of the amide carbonyl oxygen of the protein backbone in hydrogen bonding using UVPD-HEM is demonstrated to show significant agreement with the hydrogen-bonding motifs derived from molecular dynamics simulations and X-ray crystal structures.

  4. State-to-state photodissociation dynamics of triatomic molecules: H2O in the B band

    International Nuclear Information System (INIS)

    Jiang Bin; Xie Daiqian; Guo Hua

    2012-01-01

    State-to-state photodissociation dynamics of H 2 O in its B band has been investigated quantum mechanically on a new set of non-adiabatically coupled potential energy surfaces for the lowest two 1 A' states of H 2 O, which are developed at the internally contracted multi-reference configuration interaction level with the aug-cc-pVQZ basis set. Quantum dynamical calculations carried out using the Chebyshev propagator yield absorption spectra, product state distributions, branching ratios, and differential cross sections, which are in reasonably good agreement with the latest experimental results. Particular focus is placed here on the dependence of various dynamical observables on the photon energy. Detailed analyses of the dynamics have assigned the diffuse structure in absorption spectrum to short-time recurring dynamics near the HOH conical intersection. The non-adiabatic dissociation to the ground state OH product via the HOH conical intersection is facile, direct, fast, and produces rotationally hot OH(X-tilde) products. On the other hand, the adiabatic channel on the excited state leading to the OH(A-tilde) product is dominated by long-lived resonances, which depend sensitively on the potential energy surfaces.

  5. Photodissociation of the acetone cation at 355 nm using the velocity imaging technique

    Science.gov (United States)

    Jackson, William M.; Xu, Dadong

    2000-09-01

    Photodissociation of acetone cations, CH3COCH3+, at 355 nm has been studied by means of the ion velocity imaging technique. Acetone cations are produced via direct photoionization of a supersonic beam of acetone at 118 nm generated by frequency tripling the 355 nm laser. Only the acetyl cation, CH3CO+, could be detected as a dissociation product in the time-of-flight mass spectrometer. The acetyl ion signal depends upon the fifth power of the 355 nm laser energy, while the acetone ion signal depends upon the third power. This suggests that the fragment ion is produced via two-photon absorption of 355 nm photons by the acetone cation. The total translational energy distribution and angular distribution of acetyl cation were derived from the 2D images of CH3CO+ for the reaction CH3COCH3++2hν355nm→CH3CO++CH3*. The translational energy distribution suggests that methyl radicals are produced in two electronically excited states, the Rydberg 3s 1 2A1' and the valence 1 2A″ states. The anisotropy parameter β shows that the Rydberg state is formed via a perpendicular excitation and the valence state via a parallel transition.

  6. Photodissociation of C3H5Br and C4H7Br at 234 nm

    International Nuclear Information System (INIS)

    Kim, Hyun Kook; Paul, Dababrata; Hong, Ki Ryong; Cho, Ha Na; Kim, Tae Kyu; Lee, Kyoung Seok

    2012-01-01

    The photodissociation dynamics of cyclopropyl bromide (C-3H 5 Br) and cyclobutyl bromide (C 4 H 7 Br) at 234 nm was investigated. A two-dimensional photofragment ion-imaging technique coupled with a [2+1] resonance enhanced multiphoton ionization scheme was utilized to obtain speed and angular distributions of the nascent Br( 2 P 3/2 ) and Br*( 2 P 1/2 ) atoms. The recoil anisotropies for the Br and Br* channels were measured to be βBr = 0.92 ± 0.03 and βBr* = 1.52 ± 0.04 for C 3 H 5 Br and βBr = 1.10 ± 0.03 and βBr* = 1.49 ± 0.05 for C 4 H 7 Br. The relative quantum yield for Br was found to be ΦBr = 0.13 ± 0.03 and for C 3 H 5 Br and C 4 H 7 Br, respectively. The soft radical limit of the impulsive model adequately modeled the related energy partitioning. The nonadiabatic transition probability from the 3A' and 4A' potential energy surfaces was estimated and discussed

  7. State-resolved Photodissociation and Radiative Association Data for the Molecular Hydrogen Ion

    Science.gov (United States)

    Zammit, Mark C.; Savage, Jeremy S.; Colgan, James; Fursa, Dmitry V.; Kilcrease, David P.; Bray, Igor; Fontes, Christopher J.; Hakel, Peter; Timmermans, Eddy

    2017-12-01

    We present state-resolved (electronic, vibrational, and rotational) cross sections and rate coefficients for the photodissociation (PD) of {{{H}}}2+ and radiative association (RA) of H–H+. We developed a fully quantum mechanical approach within the nonrelativistic Born–Oppenheimer approximation to describe {{{H}}}2+ and calculate the data for transitions between the ground electronic state 1s{σ }g and the 2p{σ }u, 2p{π }u, 3p{σ }u, 3p{π }u, 4p{σ }u, 4f{σ }u, 4f{π }u, and 4p{π }u electronic states (i.e., up to {{{H}}}2+ n = 4). Tables of the dipole-matrix elements and energies needed to calculate state-resolved cross sections and rate coefficients will be made publicly available. These data could be important in astrophysical models when dealing with photon wavelengths (or radiation temperature distributions that are weighted toward such wavelengths) around 100 nm. For example, at these wavelengths and a material temperature of 8400 K, the LTE-averaged PD cross section via the (second electronically excited) 2p{π }u state is over three times larger than the PD cross section via the (first electronically excited) 2p{σ }u state.

  8. Differential Fragmentation of Mobility-Selected Glycans via Ultraviolet Photodissociation and Ion Mobility-Mass Spectrometry

    Science.gov (United States)

    Morrison, Kelsey A.; Clowers, Brian H.

    2017-06-01

    The alternative dissociation pathways initiated by ultraviolet photodissociation (UVPD) compared with collision-induced dissociation (CID) may provide useful diagnostic fragments for biomolecule identification, including glycans. However, underivatized glycans do not commonly demonstrate strong UV absorbance, resulting in low fragmentation yields for UVPD spectra. In contrast to UVPD experiments that leverage covalent modification of glycans, we detail the capacity of metal adduction to yield comparatively rich UVPD fragmentation patterns and enhance separation factors for an isomeric glycan set in a drift tube ion mobility system. Ion mobility and UVPD-MS spectra for two N-acetyl glycan isomers were examined, each adducted with sodium or cobalt cations, with the latter providing fragment yield gains of an order of magnitude versus sodium adducts. Furthermore, our glycan analysis incorporated front-end ion mobility separation such that the structural glycan isomers could still be identified even as a mixture and not simply composite spectra of isomeric standards. Cobalt adduction proved influential in the glycan separation by yielding an isomer resolution of 0.78 when analyzed simultaneously versus no discernable separation obtained with the sodium adducts. It is the combined enhancement of both isomeric drift time separation and isomer distinction with improved UVPD fragment ion yields that further bolster multivalent metal adduction for advancing glycan IM-MS experiments. [Figure not available: see fulltext.

  9. Electronic and vibrational spectroscopy and vibrationally mediated photodissociation of V+(OCO).

    Science.gov (United States)

    Citir, Murat; Altinay, Gokhan; Metz, Ricardo B

    2006-04-20

    Electronic spectra of gas-phase V+(OCO) are measured in the near-infrared from 6050 to 7420 cm(-1) and in the visible from 15,500 to 16,560 cm(-1), using photofragment spectroscopy. The near-IR band is complex, with a 107 cm(-1) progression in the metal-ligand stretch. The visible band shows clearly resolved vibrational progressions in the metal-ligand stretch and rock, and in the OCO bend, as observed by Brucat and co-workers. A vibrational hot band gives the metal-ligand stretch frequency in the ground electronic state nu3'' = 210 cm(-1). The OCO antisymmetric stretch frequency in the ground electronic state (nu1'') is measured by using vibrationally mediated photodissociation. An IR laser vibrationally excites ions to nu1'' = 1. Vibrationally excited ions selectively dissociate following absorption of a second, visible photon at the nu1' = 1 CO2, due to interaction with the metal. Larger blue shifts observed for complexes with fewer ligands agree with trends seen for larger V+(OCO)n clusters.

  10. Top-Down Hydrogen-Deuterium Exchange Analysis of Protein Structures Using Ultraviolet Photodissociation.

    Science.gov (United States)

    Brodie, Nicholas I; Huguet, Romain; Zhang, Terry; Viner, Rosa; Zabrouskov, Vlad; Pan, Jingxi; Petrotchenko, Evgeniy V; Borchers, Christoph H

    2018-03-06

    Top-down hydrogen-deuterium exchange (HDX) analysis using electron capture or transfer dissociation Fourier transform mass spectrometry (FTMS) is a powerful method for the analysis of secondary structure of proteins in solution. The resolution of the method is a function of the degree of fragmentation of backbone bonds in the proteins. While fragmentation is usually extensive near the N- and C-termini, electron capture (ECD) or electron transfer dissociation (ETD) fragmentation methods sometimes lack good coverage of certain regions of the protein, most often in the middle of the sequence. Ultraviolet photodissociation (UVPD) is a recently developed fast-fragmentation technique, which provides extensive backbone fragmentation that can be complementary in sequence coverage to the aforementioned electron-based fragmentation techniques. Here, we explore the application of electrospray ionization (ESI)-UVPD FTMS on an Orbitrap Fusion Lumos Tribrid mass spectrometer to top-down HDX analysis of proteins. We have incorporated UVPD-specific fragment-ion types and fragment-ion mixtures into our isotopic envelope fitting software (HDX Match) for the top-down HDX analysis. We have shown that UVPD data is complementary to ETD, thus improving the overall resolution when used as a combined approach.

  11. Isotope separation of 17O by photodissociation of ozone with near-infrared laser irradiation

    Science.gov (United States)

    Hayashida, Shigeru; Kambe, Takashi; Sato, Tetsuya; Igarashi, Takehiro; Kuze, Hiroaki

    2012-04-01

    Oxygen-17 is a stable oxygen isotope useful for various diagnostics in both engineering and medical applications. Enrichment of 17O, however, has been very costly due to the lack of appropriate methods that enable efficient production of 17O on an industrial level. In this paper, we report the first 17O-selective photodissociation of ozone at a relatively high pressure, which has been achieved by irradiating a gas mixture of 10 vol% O3-90 vol% CF4 with narrowband laser. The experiment was conducted on a pilot-plant scale. A total laser power of 1.6 W was generated by external-cavity diode lasers with all the laser wavelengths fixed at the peak of an absorption line of 16O16O17O around 1 μm. The beams were introduced into a 25 -m long photoreaction cell under the sealed-off condition with a total pressure of 20 kPa. Lower cell temperature reduced the background decomposition of ozone, and at the temperature of 158 K, an 17O enrichment factor of 2.2 was attained.

  12. Photodissociation dynamics of propene at 157.6 nm: Kinetic energy distributions and branching ratios

    International Nuclear Information System (INIS)

    Lee, S.-H.; Lee, Y.-Y.; Lee, Yuan T.; Yang Xueming

    2003-01-01

    Photodissociation dynamics of propene at 157.6 nm has been investigated in a molecular beam apparatus using the photofragment translational spectroscopic technique combined with the vacuum ultraviolet ionization method. Eleven photofragments have been successfully detected and ascribed to eight (five binary and three triple) dissociation channels: namely, C 3 H 5 +H, C 3 H 4 +H+H, C 3 H 4 +H 2 , C 3 H 3 +H 2 +H, C 2 H 4 +CH 2 , C 2 H 3 +CH 3 , C 2 H 2 +CH 4 , and C 2 H 2 +CH 3 +H. Their branching ratios have been determined to be 1%, 7%, 2 H 2 +CH 3 +H channel. In addition, the averaged kinetic energy releases and the fractions in translational energy have also been determined from the measured kinetic energy distributions. For the binary dissociation channels, the fractions in translational energy are less than 18% except the C 3 H 5 +H channel, whereas they are more than 42% for the triple dissociation channels. An intriguing finding indicates that the C 2 H 4 +CH 2 channel has a nearly identical kinetic energy distribution and a similar branching ratio to the C 2 H 3 +CH 3 channel, although the former undergoes a three-center elimination process different from the C-C bond rupture occurring in the latter

  13. Photodissociation of HCN and HNC isomers in the 7-10 eV energy range

    Energy Technology Data Exchange (ETDEWEB)

    Chenel, Aurelie; Roncero, Octavio, E-mail: octavio.roncero@csic.es [Instituto de Física Fundamental (IFF-CSIC), C.S.I.C., Serrano 123, 28006 Madrid (Spain); Aguado, Alfredo [Departamento de Química Física Aplicada (UAM), Unidad Asociada a IFF-CSIC, Facultad de Ciencias Módulo 14, Universidad Autónoma de Madrid, 28049 Madrid (Spain); Agúndez, Marcelino; Cernicharo, José [Instituto de Ciencia de Materiales de Madrid, CSIC, C/ Sor Juana Inés de la Cruz 3, 28049 Cantoblanco (Spain)

    2016-04-14

    The ultraviolet photoabsorption spectra of the HCN and HNC isomers have been simulated in the 7-10 eV photon energy range. For this purpose, the three-dimensional adiabatic potential energy surfaces of the 7 lowest electronic states, and the corresponding transition dipole moments, have been calculated, at multireference configuration interaction level. The spectra are calculated with a quantum wave packet method on these adiabatic potential energy surfaces. The spectra for the 3 lower excited states, the dissociative electronic states, correspond essentially to predissociation peaks, most of them through tunneling on the same adiabatic state. The 3 higher electronic states are bound, hereafter electronic bound states, and their spectra consist of delta lines, in the adiabatic approximation. The radiative lifetime towards the ground electronic states of these bound states has been calculated, being longer than 10 ns in all cases, much longer that the characteristic predissociation lifetimes. The spectra of HCN is compared with the available experimental and previous theoretical simulations, while in the case of HNC there are no previous studies to our knowledge. The spectrum for HNC is considerably more intense than that of HCN in the 7-10 eV photon energy range, which points to a higher photodissociation rate for HNC, compared to HCN, in astrophysical environments illuminated by ultraviolet radiation.

  14. Reinventing Chemistry

    OpenAIRE

    Whitesides, George McClelland

    2015-01-01

    Chemistry is in a period of change, from an era focused on molecules and reactions, to one in which manipulations of systems of molecules and reactions will be essential parts of controlling larger systems. This Essay traces paths from the past to possible futures.

  15. Chemistry Notes

    Science.gov (United States)

    School Science Review, 1972

    1972-01-01

    Short articles on the kinetics of the hydrogen peroxide-iodide ion reaction, simulation of fluidization catalysis, the use of Newman projection diagrams to represent steric relationships in organic chemistry, the use of synthetic substrates for proteolytic enzyme reactions, and two simple clock reactions"--hydrolysis of halogenoalkanes and…

  16. The impact of electricity consumption on CO2 emission, carbon footprint, water footprint and ecological footprint: The role of hydropower in an emerging economy.

    Science.gov (United States)

    Bello, Mufutau Opeyemi; Solarin, Sakiru Adebola; Yen, Yuen Yee

    2018-08-01

    The primary objective of this paper is to investigate the isolated impacts of hydroelectricity consumption on the environment in Malaysia as an emerging economy. We use four different measures of environmental degradation including ecological footprint, carbon footprint, water footprint and CO 2 emission as target variables, while controlling for GDP, GDP square and urbanization for the period 1971 to 2016. A recently introduced unit root test with breaks is utilized to examine the stationarity of the series and the bounds testing approach to cointegration is used to probe the long run relationships between the variables. VECM Granger causality technique is employed to examine the long-run causal dynamics between the variables. Sensitivity analysis is conducted by further including fossil fuels in the equations. The results show evidence of an inverted U-shaped relationship between environmental degradation and real GDP. Hydroelectricity is found to significantly reduce environmental degradation while urbanization is also not particularly harmful on the environment apart from its effect on air pollution. The VECM Granger causality results show evidence of unidirectional causality running from hydroelectricity and fossil fuels consumption to all measures of environmental degradation and real GDP per capita. There is evidence of feedback hypothesis between real GDP to all environmental degradation indices. The inclusion of fossil fuel did not change the behavior of hydroelectricity on the environment but fossil fuels significantly increase water footprint. Copyright © 2018 Elsevier Ltd. All rights reserved.

  17. Water footprint as a tool for integrated water resources management

    Science.gov (United States)

    Aldaya, Maite; Hoekstra, Arjen

    2010-05-01

    In a context where water resources are unevenly distributed and, in some regions precipitation and drought conditions are increasing, enhanced water management is a major challenge to final consumers, businesses, water resource users, water managers and policymakers in general. By linking a large range of sectors and issues, virtual water trade and water footprint analyses provide an appropriate framework to find potential solutions and contribute to a better management of water resources. The water footprint is an indicator of freshwater use that looks not only at direct water use of a consumer or producer, but also at the indirect water use. The water footprint of a product is the volume of freshwater used to produce the product, measured over the full supply chain. It is a multi-dimensional indicator, showing water consumption volumes by source and polluted volumes by type of pollution; all components of a total water footprint are specified geographically and temporally. The water footprint breaks down into three components: the blue (volume of freshwater evaporated from surface or groundwater systems), green (water volume evaporated from rainwater stored in the soil as soil moisture) and grey water footprint (the volume of polluted water associated with the production of goods and services). Closely linked to the concept of water footprint is that of virtual water trade, which represents the amount of water embedded in traded products. Many nations save domestic water resources by importing water-intensive products and exporting commodities that are less water intensive. National water saving through the import of a product can imply saving water at a global level if the flow is from sites with high to sites with low water productivity. Virtual water trade between nations and even continents could thus be used as an instrument to improve global water use efficiency and to achieve water security in water-poor regions of the world. The virtual water trade

  18. Chemistry and physics

    International Nuclear Information System (INIS)

    Broerse, J.J.; Barendsen, G.W.; Kal, H.B.; Kogel, A.J. van der

    1983-01-01

    This book contains the extended abstracts of the contributions of the poster workshop sessions on chemistry and physics of the 7th international congress of radiation research. They cover the following main topics: primary processes in radiation physics and chemistry, general chemistry in radiation chemistry, DNA and model systems in radiation chemistry, molecules of biological interest in radiation chemistry, techniques in radiation chemistry, hot atom chemistry. refs.; figs.; tabs

  19. Fine chemistry

    International Nuclear Information System (INIS)

    Laszlo, P.

    1988-01-01

    The 1988 progress report of the Fine Chemistry laboratory (Polytechnic School, France) is presented. The research programs are centered on the renewal of the organic chemistry most important reactions and on the invention of new, highly efficient and highly selective reactions, by applying low cost reagents and solvents. An important research domain concerns the study and fabrication of new catalysts. They are obtained by means of the reactive sputtering of the metals and metal oxydes thin films. The Monte Carlo simulations of the long-range electrostatic interaction in a clay and the obtention of acrylamides from anhydrous or acrylic ester are summarized. Moreover, the results obtained in the field of catalysis are also given. The published papers and the congress communications are included [fr

  20. Bivariate Genomic Footprinting Detects Changes in Transcription Factor Activity

    Directory of Open Access Journals (Sweden)

    Songjoon Baek

    2017-05-01

    Full Text Available In response to activating signals, transcription factors (TFs bind DNA and regulate gene expression. TF binding can be measured by protection of the bound sequence from DNase digestion (i.e., footprint. Here, we report that 80% of TF binding motifs do not show a measurable footprint, partly because of a variable cleavage pattern within the motif sequence. To more faithfully portray the effect of TFs on chromatin, we developed an algorithm that captures two TF-dependent effects on chromatin accessibility: footprinting and motif-flanking accessibility. The algorithm, termed bivariate genomic footprinting (BaGFoot, efficiently detects TF activity. BaGFoot is robust to different accessibility assays (DNase-seq, ATAC-seq, all examined peak-calling programs, and a variety of cut bias correction approaches. BaGFoot reliably predicts TF binding and provides valuable information regarding the TFs affecting chromatin accessibility in various biological systems and following various biological events, including in cases where an absolute footprint cannot be determined.

  1. Twelve metropolitan carbon footprints. A preliminary comparative global assessment

    International Nuclear Information System (INIS)

    Sovacool, Benjamin K.; Brown, Marilyn A.

    2010-01-01

    A dearth of available data on carbon emissions and comparative analysis between metropolitan areas make it difficult to confirm or refute best practices and policies. To help provide benchmarks and expand our understanding of urban centers and climate change, this article offers a preliminary comparison of the carbon footprints of 12 metropolitan areas. It does this by examining emissions related to vehicles, energy used in buildings, industry, agriculture, and waste. The carbon emissions from these sources - discussed here as the metro area's partial carbon footprint - provide a foundation for identifying the pricing, land use, help metropolitan areas throughout the world respond to climate change. The article begins by exploring a sample of the existing literature on urban morphology and climate change and explaining the methodology used to calculate each area's carbon footprint. The article then depicts the specific carbon footprints for Beijing, Jakarta, London, Los Angeles, Manila, Mexico City, New Delhi, New York, Sao Paulo, Seoul, Singapore, and Tokyo and compares these to respective national averages. It concludes by offering suggestions for how city planners and policymakers can reduce the carbon footprint of these and possibly other large urban areas. (author)

  2. Radioanalytical chemistry

    International Nuclear Information System (INIS)

    1982-01-01

    The bibliography of Hungarian literature in the field of radioanalytical chemistry covers the four-year period 1976-1979. The list of papers contains 290 references in the alphabetical order of the first authors. The majority of the titles belongs to neutron activation analysis, labelling, separation and determination of radioactive isotopes. Other important fields like radioimmunoassay, environmental protection etc. are covered as well. (Sz.J.)

  3. Analytical chemistry

    International Nuclear Information System (INIS)

    Anon.

    1985-01-01

    The division for Analytical Chemistry continued to try and develope an accurate method for the separation of trace amounts from mixtures which, contain various other elements. Ion exchange chromatography is of special importance in this regard. New separation techniques were tried on certain trace amounts in South African standard rock materials and special ceramics. Methods were also tested for the separation of carrier-free radioisotopes from irradiated cyclotron discs

  4. Industrial chemistry engineering

    International Nuclear Information System (INIS)

    1993-01-01

    This book on industrial chemistry engineering is divided in two parts. The first part deals with industrial chemistry, inorganic industrial chemistry, organic industrial chemistry, analytical chemistry and practical questions. The last parts explain the chemical industry, a unit parts and thermodynamics in chemical industry and reference. It reveals the test subjects for the industrial chemistry engineering with a written examination and practical skill.

  5. Computational chemistry

    Science.gov (United States)

    Arnold, J. O.

    1987-01-01

    With the advent of supercomputers, modern computational chemistry algorithms and codes, a powerful tool was created to help fill NASA's continuing need for information on the properties of matter in hostile or unusual environments. Computational resources provided under the National Aerodynamics Simulator (NAS) program were a cornerstone for recent advancements in this field. Properties of gases, materials, and their interactions can be determined from solutions of the governing equations. In the case of gases, for example, radiative transition probabilites per particle, bond-dissociation energies, and rates of simple chemical reactions can be determined computationally as reliably as from experiment. The data are proving to be quite valuable in providing inputs to real-gas flow simulation codes used to compute aerothermodynamic loads on NASA's aeroassist orbital transfer vehicles and a host of problems related to the National Aerospace Plane Program. Although more approximate, similar solutions can be obtained for ensembles of atoms simulating small particles of materials with and without the presence of gases. Computational chemistry has application in studying catalysis, properties of polymers, all of interest to various NASA missions, including those previously mentioned. In addition to discussing these applications of computational chemistry within NASA, the governing equations and the need for supercomputers for their solution is outlined.

  6. Green chemistry

    International Nuclear Information System (INIS)

    Warner, John C.; Cannon, Amy S.; Dye, Kevin M.

    2004-01-01

    A grand challenge facing government, industry, and academia in the relationship of our technological society to the environment is reinventing the use of materials. To address this challenge, collaboration from an interdisciplinary group of stakeholders will be necessary. Traditionally, the approach to risk management of materials and chemicals has been through inerventions intended to reduce exposure to materials that are hazardous to health and the environment. In 1990, the Pollution Prevention Act encouraged a new tact-elimination of hazards at the source. An emerging approach to this grand challenge seeks to embed the diverse set of environmental perspectives and interests in the everyday practice of the people most responsible for using and creating new materials--chemists. The approach, which has come to be known as Green Chemistry, intends to eliminate intrinsic hazard itself, rather than focusing on reducing risk by minimizing exposure. This chapter addresses the representation of downstream environmental stakeholder interests in the upstream everyday practice that is reinventing chemistry and its material inputs, products, and waste as described in the '12 Principles of Green Chemistry'

  7. A new 2D climate model with chemistry and self consistent eddy-parameterization. The impact of airplane NO{sub x} on the chemistry of the atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Gepraegs, R; Schmitz, G; Peters, D [Institut fuer Atmosphaerenphysik, Kuehlungsborn (Germany)

    1998-12-31

    A 2D version of the ECHAM T21 climate model has been developed. The new model includes an efficient spectral transport scheme with implicit diffusion. Furthermore, photodissociation and chemistry of the NCAR 2D model have been incorporated. A self consistent parametrization scheme is used for eddy heat- and momentum flux in the troposphere. It is based on the heat flux parametrization of Branscome and mixing-length formulation for quasi-geostrophic vorticity. Above 150 hPa the mixing-coefficient K{sub yy} is prescribed. Some of the model results are discussed, concerning especially the impact of aircraft NO{sub x} emission on the model chemistry. (author) 6 refs.

  8. A new 2D climate model with chemistry and self consistent eddy-parameterization. The impact of airplane NO{sub x} on the chemistry of the atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Gepraegs, R.; Schmitz, G.; Peters, D. [Institut fuer Atmosphaerenphysik, Kuehlungsborn (Germany)

    1997-12-31

    A 2D version of the ECHAM T21 climate model has been developed. The new model includes an efficient spectral transport scheme with implicit diffusion. Furthermore, photodissociation and chemistry of the NCAR 2D model have been incorporated. A self consistent parametrization scheme is used for eddy heat- and momentum flux in the troposphere. It is based on the heat flux parametrization of Branscome and mixing-length formulation for quasi-geostrophic vorticity. Above 150 hPa the mixing-coefficient K{sub yy} is prescribed. Some of the model results are discussed, concerning especially the impact of aircraft NO{sub x} emission on the model chemistry. (author) 6 refs.

  9. Photodissociation dynamics of CH3C(O)SH in argon matrix: A QM/MM nonadiabatic dynamics simulation

    Science.gov (United States)

    Xia, Shu-Hua; Liu, Xiang-Yang; Fang, Qiu; Cui, Ganglong

    2015-11-01

    In this work, we have first employed the combined quantum mechanics/molecular mechanics (QM/MM) method to study the photodissociation mechanism of thioacetic acid CH3C(O)SH in the S1, T1, and S0 states in argon matrix. CH3C(O)SH is treated quantum mechanically using the complete active space self-consistent field and complete active space second-order perturbation theory methods; argon matrix is described classically using Lennard-Jones potentials. We find that the C-S bond fission is predominant due to its small barriers of ca. 3.0 and 1.0 kcal/mol in the S1 and T1 states. It completely suppresses the nearby C—C bond fission. After the bond fission, the S1 radical pair of CH3CO and SH can decay to the S0 and T1 states via internal conversion and intersystem crossing, respectively. In the S0 state, the radical pair can either recombine to form CH3C(O)SH or proceed to form molecular products of CH2CO and H2S. We have further employed our recently developed QM/MM generalized trajectory-based surface-hopping method to simulate the photodissociation dynamics of CH3C(O)SH. In 1 ps dynamics simulation, 56% trajectories stay at the Franck-Condon region; the S1 C—S bond fission takes place in the remaining 44% trajectories. Among all nonadiabatic transitions, the S1 → S0 internal conversion is major (55%) but the S1 → T1 intersystem crossing is still comparable and cannot be ignored, which accounts for 28%. Finally, we have found a radical channel generating the molecular products of CH2CO and H2S, which is complementary to the concerted molecular channel. The present work sets the stage for simulating photodissociation dynamics of similar thio-carbonyl systems in matrix.

  10. Three-body dissociations: The photodissociation of dimethyl sulfoxide at 193 nm

    Energy Technology Data Exchange (ETDEWEB)

    Blank, D.A.; North, S.W.; Stranges, D. [Lawrence Berkeley National Lab., CA (United States)] [and others

    1997-04-01

    When a molecule with two equivalent chemical bonds is excited above the threshold for dissociation of both bonds, how the rupture of the two bonds is temporally coupled becomes a salient question. Following absorption at 193 nm dimethyl sulfoxide (CH{sub 3}SOCH{sub 3}) contains enough energy to rupture both C-S bonds. This can happen in a stepwise (reaction 1) or concerted (reaction 2) fashion where the authors use rotation of the SOCH{sub 3} intermediate prior to dissociation to define a stepwise dissociation: (1) CH{sub 3}SOCH{sub 3} {r_arrow} 2CH{sub 3} + SO; (2a) CH{sub 3}SOCH{sub 3} {r_arrow} CH{sub 3} + SOCH{sub 3}; and (2b) SOCH{sub 3} {r_arrow} SO + CH{sub 3}. Recently, the dissociation of dimethyl sulfoxide following absorption at 193 nm was suggested to involve simultaneous cleavage of both C-S bonds on an excited electronic surface. This conclusion was inferred from laser induced fluorescence (LIF) and resonant multiphoton ionization (2+1 REMPI) measurements of the internal energy content in the CH{sub 3} and SO photoproducts and a near unity quantum yield measured for SO. Since this type of concerted three body dissociation is very interesting and a rather rare event in photodissociation dynamics, the authors chose to investigate this system using the technique of photofragment translational spectroscopy at beamline 9.0.2.1. The soft photoionization provided by the VUV undulator radiation allowed the authors to probe the SOCH{sub 3} intermediate which had not been previously observed and provided good evidence that the dissociation of dimethyl sulfoxide primarily proceeds via a two step dissociation, reaction 2.

  11. Geometric phase effects in the coherent control of the branching ratio of photodissociation products of phenol

    International Nuclear Information System (INIS)

    Abe, Mayumi; Ohtsuki, Yukiyoshi; Fujimura, Yuichi; Lan, Zhenggang; Domcke, Wolfgang

    2006-01-01

    Optimal control simulation is used to examine the control mechanisms in the photodissociation of phenol within a two-dimensional, three-electronic-state model with two conical intersections. This model has two channels for H-atom elimination, which correspond to the 2 π and 2 σ states of the phenoxyl radical. The optimal pulse that enhances 2 σ dissociation initially generates a wave packet on the S 1 potential-energy surface of phenol. This wave packet is bifurcated at the S 2 -S 1 conical intersection into two components with opposite phases because of the geometric phase effect. The destructive interference caused by the geometric phase effect reduces the population around the S 1 -S 0 conical intersection, which in turn suppresses nonadiabatic transitions and thus enhances dissociation to the 2 σ limit. The optimal pulse that enhances S 0 dissociation, on the other hand, creates a wave packet on the S 2 potential-energy surface of phenol via an intensity borrowing mechanism, thus avoiding geometric phase effects at the S 2 -S 1 conical intersection. This wave packet hits the S 1 -S 0 conical intersection directly, resulting in preferred dissociation to the 2 π limit. The optimal pulse that initially prepares the wave packet on the S 1 potential-energy surface (PES) has a higher carrier frequency than the pulse that prepares the wave packet on the S 2 PES. This counterintuitive effect is explained by the energy-level structure and the S 2 -S 1 vibronic coupling mechanism

  12. Photodissociation dynamics of CO2 at 157.6 nm by photofragment-translational spectroscopy

    International Nuclear Information System (INIS)

    Stolow, A.; Lee, Y.T.

    1993-01-01

    The photodissociation of CO 2 at 157 nm was studied by the photofragment-translational spectroscopy technique. Product time-of-flight spectra were recorded and center-of-mass translational energy distributions were determined. Two electronic channels were observed---one forming O( 1 D) and the other O( 3 P). With previously determined anisotropy parameters of β=2 for the O( 3 P) channel and β=0 for the O( 1 D) channel, an electronic branching ratio of 6%±2%O( 3 P) was obtained, consistent with previous results. The translational energy distribution for the CO(v)+O( 3 P) channel was very broad (over 30 kcal/mol) and appeared to peak near CO(v=0). The value of β=2 for the O( 3 P) channel was confirmed by comparing Doppler profiles, derived from our measured translational energy distribution, with previously measured Doppler profiles. This suggests that the O( 3 P) channel arises from a direct transition to an excited triplet state. The O( 1 D) channel had a structured time-of-flight which related to rovibrational distributions of the CO product. The influence of the excitation of the CO 2 (ν 2 ) bending mode was investigated and shown to have a small but not negligible contribution. Based upon a comparison of our data with a previous vacuum-ultraviolet (VUV) laser induced fluorescence study, we obtain as our best estimate of the vibrational branching ratio, CO(v=0)/CO(v=1)=1.9, for the CO(v)+O( 1 D) channel

  13. Photodissociation comprehensive study of OH- on alkali halides and their interaction with colour centers

    International Nuclear Information System (INIS)

    Gomes, L.

    1985-01-01

    This work shows that the OH - defect induces changes in the electronics processes of the alkali halides such as in radiation damage and optical cycles of colour centers. Two cases were considered: with the presence of an OH - ion in the (1) excited state and (2) in the ground state; 1) the comprehensive study of resonant OH - photodissociation in several hosts showed that deep traps (for electrons) can be produced from the OH - dissociation. These traps can be effective for the capture of electrons produced in the radiation damage of the lattice as well as for trapping electrons from ionized color centers. It was observed a second channel (new) for the de-excitation of the (OH - )* molecule in KI and RbI. This effect can be effective only when the lattice around the molecule holds a large enough interstitial space. This new mechanism is responsible for the strong production at LNT of F centers and OH 0 molecules at the expenses of OH - defects. Considering the complete investigation of the full cycle it was proposed a phenomenological model that would explain the observed behaviour when one covers a wide variation of lattice parameters (KCl -> RbI); 2) It was verified that the OH - ion present in the lattice induces strong changes in the de-excitation processes of electronic defects with a spread out wave function (like F centers). A change in the reorientation behaviour of excited F 2 and F + 2 centers was also verified. Two main effects should be mentioned: A) The induced de-excitation is very fast and non-radiative on F centers. B) Another type of system investigated (F 2 and F + 2 ) has shown an intense increase of the speed of reorientation of the F 2 and F + 2 excited centers. (autor) [pt

  14. Femtosecond time-resolved photodissociation dynamics of methyl halide molecules on ultrathin gold films

    Directory of Open Access Journals (Sweden)

    Mihai E. Vaida

    2011-09-01

    Full Text Available The photodissociation of small organic molecules, namely methyl iodide, methyl bromide, and methyl chloride, adsorbed on a metal surface was investigated in real time by means of femtosecond-laser pump–probe mass spectrometry. A weakly interacting gold surface was employed as substrate because the intact adsorption of the methyl halide molecules was desired prior to photoexcitation. The gold surface was prepared as an ultrathin film on Mo(100. The molecular adsorption behavior was characterized by coverage dependent temperature programmed desorption spectroscopy. Submonolayer preparations were irradiated with UV light of 266 nm wavelength and the subsequently emerging methyl fragments were probed by photoionization and mass spectrometric detection. A strong dependence of the excitation mechanism and the light-induced dynamics on the type of molecule was observed. Possible photoexcitation mechanisms included direct photoexcitation to the dissociative A-band of the methyl halide molecules as well as the attachment of surface-emitted electrons with transient negative ion formation and subsequent molecular fragmentation. Both reaction pathways were energetically possible in the case of methyl iodide, yet, no methyl fragments were observed. As a likely explanation, the rapid quenching of the excited states prior to fragmentation is proposed. This quenching mechanism could be prevented by modification of the gold surface through pre-adsorption of iodine atoms. In contrast, the A-band of methyl bromide was not energetically directly accessible through 266 nm excitation. Nevertheless, the one-photon-induced dissociation was observed in the case of methyl bromide. This was interpreted as being due to a considerable energetic down-shift of the electronic A-band states of methyl bromide by about 1.5 eV through interaction with the gold substrate. Finally, for methyl chloride no photofragmentation could be detected at all.

  15. Three-body dissociations: The photodissociation of dimethyl sulfoxide at 193 nm

    International Nuclear Information System (INIS)

    Blank, D.A.; North, S.W.; Stranges, D.

    1997-01-01

    When a molecule with two equivalent chemical bonds is excited above the threshold for dissociation of both bonds, how the rupture of the two bonds is temporally coupled becomes a salient question. Following absorption at 193 nm dimethyl sulfoxide (CH 3 SOCH 3 ) contains enough energy to rupture both C-S bonds. This can happen in a stepwise (reaction 1) or concerted (reaction 2) fashion where the authors use rotation of the SOCH 3 intermediate prior to dissociation to define a stepwise dissociation: (1) CH 3 SOCH 3 → 2CH 3 + SO; (2a) CH 3 SOCH 3 → CH 3 + SOCH 3 ; and (2b) SOCH 3 → SO + CH 3 . Recently, the dissociation of dimethyl sulfoxide following absorption at 193 nm was suggested to involve simultaneous cleavage of both C-S bonds on an excited electronic surface. This conclusion was inferred from laser induced fluorescence (LIF) and resonant multiphoton ionization (2+1 REMPI) measurements of the internal energy content in the CH 3 and SO photoproducts and a near unity quantum yield measured for SO. Since this type of concerted three body dissociation is very interesting and a rather rare event in photodissociation dynamics, the authors chose to investigate this system using the technique of photofragment translational spectroscopy at beamline 9.0.2.1. The soft photoionization provided by the VUV undulator radiation allowed the authors to probe the SOCH 3 intermediate which had not been previously observed and provided good evidence that the dissociation of dimethyl sulfoxide primarily proceeds via a two step dissociation, reaction 2

  16. Surveying the Environmental Footprint of Urban Food Consumption

    DEFF Research Database (Denmark)

    Goldstein, Benjamin Paul; Birkved, Morten; Fernandez, John

    2017-01-01

    Assessments of urban metabolism (UM) are well situated to identify the scale, components, and direction of urban and energy flows in cities and have been instrumental in benchmarking and monitoring the key levers of urban environmental pressure, such as transport, space conditioning......, and electricity. Hitherto, urban food consumption has garnered scant attention both in UM accounting (typically lumped with “biomass”) and on the urban policy agenda, despite its relevance to local and global environmental pressures. With future growth expected in urban population and wealth, an accounting...... of the environmental footprint from urban food demand (“foodprint”) is necessary. This article reviews 43 UM assessments including 100 cities, and a total of 132 foodprints in terms of mass, carbon footprint, and ecological footprint and situates it relative to other significant environmental drivers (transport...

  17. Baseline ecological footprint of Sandia National Laboratories, New Mexico.

    Energy Technology Data Exchange (ETDEWEB)

    Coplen, Amy K.; Mizner, Jack Harry,; Ubechel, Norion M.

    2009-01-01

    The Ecological Footprint Model is a mechanism for measuring the environmental effects of operations at Sandia National Laboratories in Albuquerque, New Mexico (SNL/NM). This analysis quantifies environmental impact associated with energy use, transportation, waste, land use, and water consumption at SNL/NM for fiscal year 2005 (FY05). Since SNL/NMs total ecological footprint (96,434 gha) is greater than the waste absorption capacity of its landholdings (338 gha), it created an ecological deficit of 96,096 gha. This deficit is equal to 886,470lha, or about 3,423 square miles of Pinyon-Juniper woodlands and desert grassland. 89% of the ecological footprint can be attributed to energy use, indicating that in order to mitigate environmental impact, efforts should be focused on energy efficiency, energy reduction, and the incorporation of additional renewable energy alternatives at SNL/NM.

  18. Human footprints on greenhouse gas fluxes in cryogenic ecosystems

    Science.gov (United States)

    Karelin, D. V.; Goryachkin, S. V.; Zamolodchikov, D. G.; Dolgikh, A. V.; Zazovskaya, E. P.; Shishkov, V. A.; Kraev, G. N.

    2017-12-01

    Various human footprints on the flux of biogenic greenhouse gases from permafrost-affected soils in Arctic and boreal domains in Russia are considered. Tendencies of significant growth or suppression of soil CO2 fluxes change across types of human impact. Overall, the human impacts increase the mean value and variance of local soil CO2 flux. Human footprint on methane exchange between soil and atmosphere is mediated by drainage. However, all the types of human impact suppress the sources and increase sinks of methane to the land ecosystems. N2O flux grew under the considered types of human impact. Based on the results, we suggest that human footprint on soil greenhouse gases fluxes is comparable to the effect of climate change at an annual to decadal timescales.

  19. Control of HOD photodissociation dynamics via bond-selective infrared multiphoton excitation and a femtosecond ultraviolet laser pulse

    DEFF Research Database (Denmark)

    Amstrup, Bjarne; Henriksen, Niels Engholm

    1992-01-01

    moment, excites the molecule to a dissociative electronic state. We consider the HOD molecule which is ideal due to the local mode structure of the vibrational states. It is shown that selective and localized bond stretching can be created in simple laser fields. When such a nonstationary vibrating HOD...... molecule is photodissociated with a short laser pulse (~5 fs) complete selectivity between the channels H+OD and D+OH is observed over the entire absorption band covering these channels. The Journal of Chemical Physics is copyrighted by The American Institute of Physics....

  20. A carbon footprint simulation model for the cork oak sector.

    Science.gov (United States)

    Demertzi, Martha; Paulo, Joana Amaral; Arroja, Luís; Dias, Ana Cláudia

    2016-10-01

    In the present study, a simulation model for the calculation of the carbon footprint of the cork oak sector (CCFM) is developed for the first time. A life cycle approach is adopted including the forest management, manufacturing, use and end-of-life stages. CCFM allows the user to insert the cork type used as raw material and its respective quantity and the distances in-between the various stages. The user can choose among different end-of-life destination options for the used cork products. The option of inserting different inputs, allows the use of the present simulation model for different cork oak systems, in different countries and with different conditions. CCFM allows the identification of the stages and products with the greatest carbon footprint and thus, a better management of the sector from an environmental perspective. The Portuguese cork oak sector is used as an application example of the model. The results obtained showed that the agglomeration industry is the hotspot for the carbon footprint of the cork sector mainly due to the production of the resins that are mixed with the cork granules for the production of agglomerated cork products. The consideration of the biogenic carbon emissions and sequestration of carbon at the forest in the carbon footprint, resulted to a great decrease of the sector's carbon footprint. Future actions for improvement are suggested in order to decrease the carbon footprint of the entire cork sector. It was found that by decreasing by 10% the emission factor of the agglomeration and transformation industries, substituting the transport trucks by more recent ones and by decreasing by 10% the cork products reaching the landfilling end-of-life destinations (while increasing the quantities reaching incineration and recycling), a decrease of the total CF (excluding the biogenic emissions and sequestration) of the entire cork industry by 10% can be achieved. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. The carbon footprint of Greek households (1995–2012)

    International Nuclear Information System (INIS)

    Markaki, M.; Belegri-Roboli, A.; Sarafidis, U.; Mirasgedis, S.

    2017-01-01

    The goal of this paper is twofold: i) to investigate the carbon footprint of Greek households throughout the period 1995–2012, in order to identify the main socio-economic factors that affect GHG emissions, and ii) to evaluate the effectiveness of the implemented policies to tackle climate change. In this, a consumption-based emissions inventory approach is applied. The analysis is based on an environmentally-extended input-output model including direct CO_2 emissions from households, indirect CO_2 emissions from electricity consumption and indirect CO_2 emissions from energy used in the production of goods and services purchased by households, domestic or imported. Statistical analysis and appropriate regression models were developed in order to identify the main factors influencing the carbon footprint of Greek households. The results indicate that the observed trends during the period 1995–2008 can be attributed to the effect of high economic growth. This trend is partially counterbalanced by favorable weather conditions and the implementation of greenhouse mitigation policies and measures mainly in the supply side. Since 2008 the shrinking household income is the dominant driver. In addition, the effectiveness of energy conservation policies and measures in place is rather low, while the effect of imports is limited. - Highlights: • The factors influencing the carbon footprint of Greek households have been analyzed. • The analysis is based on consumption-based GHG inventories. • High economic growth resulted in carbon footprint increases during 1995–2008. • Carbon footprint reduction after 2008 is attributed to shrinking of household income. • Mitigation measures in power and manufacturing sectors reduced carbon footprint.

  2. Foot-printing of Protein Interactions by Tritium Labeling

    International Nuclear Information System (INIS)

    Mousseau, Guillaume; Thomas, Olivier P.; Agez, Morgane; Thai, Robert; Cintrat, Jean-Christophe; Rousseau, Bernard; Raffy, Quentin; Renault, Jean Philippe; Pin, Serge; Ochsenbein, Francoise

    2010-01-01

    A new foot-printing method for mapping protein interactions has been developed, using tritium as a radioactive label. As residues involved in an interaction are less labeled when the complex is formed, they can be identified via comparison of the tritium incorporation of each residue of the bound protein with that of the unbound one. Application of this foot-printing method to the complex formed by the histone H3 fragment H3 122-135 and the protein hAsflA 1-156 afforded data in good agreement with NMR results. (authors)

  3. A carbon footprint simulation model for the cork oak sector

    Energy Technology Data Exchange (ETDEWEB)

    Demertzi, Martha, E-mail: marthademertzi@ua.pt [Center for Environmental and Marine Studies (CESAM), Department of Environment and Planning, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro (Portugal); Paulo, Joana Amaral, E-mail: joanaap@isa.ulisboa.pt [Center of Forest Studies (CEF), Superior Institute of Agronomy (ISA), Tapada da Ajuda, University of Lisbon, 1349-017 Lisbon (Portugal); Arroja, Luís, E-mail: arroja@ua.pt [Center for Environmental and Marine Studies (CESAM), Department of Environment and Planning, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro (Portugal); Dias, Ana Cláudia, E-mail: acdias@ua.pt [Center for Environmental and Marine Studies (CESAM), Department of Environment and Planning, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro (Portugal)

    2016-10-01

    In the present study, a simulation model for the calculation of the carbon footprint of the cork oak sector (CCFM) is developed for the first time. A life cycle approach is adopted including the forest management, manufacturing, use and end-of-life stages. CCFM allows the user to insert the cork type used as raw material and its respective quantity and the distances in-between the various stages. The user can choose among different end-of-life destination options for the used cork products. The option of inserting different inputs, allows the use of the present simulation model for different cork oak systems, in different countries and with different conditions. CCFM allows the identification of the stages and products with the greatest carbon footprint and thus, a better management of the sector from an environmental perspective. The Portuguese cork oak sector is used as an application example of the model. The results obtained showed that the agglomeration industry is the hotspot for the carbon footprint of the cork sector mainly due to the production of the resins that are mixed with the cork granules for the production of agglomerated cork products. The consideration of the biogenic carbon emissions and sequestration of carbon at the forest in the carbon footprint, resulted to a great decrease of the sector's carbon footprint. Future actions for improvement are suggested in order to decrease the carbon footprint of the entire cork sector. It was found that by decreasing by 10% the emission factor of the agglomeration and transformation industries, substituting the transport trucks by more recent ones and by decreasing by 10% the cork products reaching the landfilling end-of-life destinations (while increasing the quantities reaching incineration and recycling), a decrease of the total CF (excluding the biogenic emissions and sequestration) of the entire cork industry by 10% can be achieved. - Highlights: • A carbon footprint simulation model (CCFM) for

  4. Ichnotaxonomy of the Laetoli trackways: The earliest hominin footprints

    Science.gov (United States)

    Meldrum, D. J.; Lockley, Martin G.; Lucas, Spencer G.; Musiba, Charles

    2011-04-01

    At 3.6 Ma, the Laetoli Pliocene hominin trackways are the earliest direct evidence of hominin bipedalism. Three decades since their discovery, not only is the question of their attribution still discussed, but marked differences in interpretation concerning the footprints' qualitative features and the inferred nature of the early hominin foot morphology remain. Here, we establish a novel ichnotaxon, Praehominipes laetoliensis, for these tracks and clarify the distinctions of these footprints from those of later hominins, especially modern humans. We also contrast hominin, human, and ape footprints to establish morphological features of these footprints correlated with a midtarsal break versus a stiff longitudinal arch. Original photos, including stereo photographs, and casts of footprints from the 1978 Laetoli excavation, confirm midtarsal flexibility, and repeatedly indicate an associated midfoot pressure ridge. In contrast, the modern human footprint reflects the derived arched-foot architecture, combined with a stiff-legged striding gait. Fossilized footprints of unshod modern human pedestrians in Hawaii and Nicaragua unambiguously illustrate these contrasts. Some points of comparisons with ape footprints are complicated by a variable hallucal position and the distinct manner of ape facultative bipedalism. In contrast to the comparatively rigid platform of the modern human foot, midtarsal flexibility is present in the chimpanzee foot. In ape locomotion, flexion at the transverse tarsal joint, referred to as the "midtarsal break," uncouples the respective functions of the prehensile forefoot and the propulsive hindfoot during grasp-climbing. At some point after the transition to habitual bipedalism, these grasp-climb adaptations, presumed to be present in the last common ancestor of apes and humans, were initially compromised by the loss of divergence of the hallux. An analogous trajectory is evident along an array of increasingly terrestrial extant ape species

  5. Quantifying environmental performance using an environmental footprint calculator

    Energy Technology Data Exchange (ETDEWEB)

    Smith, D.B.; Loney, A.C.; Chan, V. [Conestoga-Rovers & Associates, Waterloo, Ontario (Canada)

    2009-07-01

    This paper provides a case study using relevant key performance indicators (KPIs) to evaluate the environmental performance of a business. Using recognized calculation and reporting frameworks, Conestoga-Rovers & Associates (CRA) designed the Environmental Footprint Calculator to quantify the environmental performance of a Canadian construction materials company. CRA designed the Environmental Footprint calculator for our client to track and report their environmental performance in accordance with their targets, based on requirements of relevant guidance documents. The objective was to design a tool that effectively manages, calculates, and reports environmental performance to various stakeholders in a user-friendly format. (author)

  6. A carbon footprint simulation model for the cork oak sector

    International Nuclear Information System (INIS)

    Demertzi, Martha; Paulo, Joana Amaral; Arroja, Luís; Dias, Ana Cláudia

    2016-01-01

    In the present study, a simulation model for the calculation of the carbon footprint of the cork oak sector (CCFM) is developed for the first time. A life cycle approach is adopted including the forest management, manufacturing, use and end-of-life stages. CCFM allows the user to insert the cork type used as raw material and its respective quantity and the distances in-between the various stages. The user can choose among different end-of-life destination options for the used cork products. The option of inserting different inputs, allows the use of the present simulation model for different cork oak systems, in different countries and with different conditions. CCFM allows the identification of the stages and products with the greatest carbon footprint and thus, a better management of the sector from an environmental perspective. The Portuguese cork oak sector is used as an application example of the model. The results obtained showed that the agglomeration industry is the hotspot for the carbon footprint of the cork sector mainly due to the production of the resins that are mixed with the cork granules for the production of agglomerated cork products. The consideration of the biogenic carbon emissions and sequestration of carbon at the forest in the carbon footprint, resulted to a great decrease of the sector's carbon footprint. Future actions for improvement are suggested in order to decrease the carbon footprint of the entire cork sector. It was found that by decreasing by 10% the emission factor of the agglomeration and transformation industries, substituting the transport trucks by more recent ones and by decreasing by 10% the cork products reaching the landfilling end-of-life destinations (while increasing the quantities reaching incineration and recycling), a decrease of the total CF (excluding the biogenic emissions and sequestration) of the entire cork industry by 10% can be achieved. - Highlights: • A carbon footprint simulation model (CCFM) for the

  7. Quantifying environmental performance using an environmental footprint calculator

    International Nuclear Information System (INIS)

    Smith, D.B.; Loney, A.C.; Chan, V.

    2009-01-01

    This paper provides a case study using relevant key performance indicators (KPIs) to evaluate the environmental performance of a business. Using recognized calculation and reporting frameworks, Conestoga-Rovers & Associates (CRA) designed the Environmental Footprint Calculator to quantify the environmental performance of a Canadian construction materials company. CRA designed the Environmental Footprint calculator for our client to track and report their environmental performance in accordance with their targets, based on requirements of relevant guidance documents. The objective was to design a tool that effectively manages, calculates, and reports environmental performance to various stakeholders in a user-friendly format. (author)

  8. Theoretical chemistry periodicities in chemistry and biology

    CERN Document Server

    Eyring, Henry

    1978-01-01

    Theoretical Chemistry: Periodicities in Chemistry and Biology, Volume 4 covers the aspects of theoretical chemistry. The book discusses the stably rotating patterns of reaction and diffusion; the chemistry of inorganic systems exhibiting nonmonotonic behavior; and population cycles. The text also describes the mathematical modeling of excitable media in neurobiology and chemistry; oscillating enzyme reactions; and oscillatory properties and excitability of the heart cell membrane. Selected topics from the theory of physico-chemical instabilities are also encompassed. Chemists, mechanical engin

  9. Solution chemistry

    Energy Technology Data Exchange (ETDEWEB)

    None

    1973-07-01

    Research progress is reported on studies in heavy element chemistry. Topics considered are: synergistic complexes of plutonyl ion; water uptake in synergistic systems; formation constants of some uranyl BETA -diketone complexes; thermodynamic acid dissociation constants of BETA -diketones; thermodynamic formation constants of uranyl BETA -diketonates; thiocyanate complexes of some trivalent lanthanides and actinides; stability constants of actinide complexes using dinonyl naphthalenesulfonic acid extraction; TBP extraction of actinides; stability constants of complexes of Pu(III) with 5- sulfosalicycllc acid; and solvent extraction behavior of Pu( VII). (DHM)

  10. Interstellar chemistry.

    Science.gov (United States)

    Klemperer, William

    2006-08-15

    In the past half century, radioastronomy has changed our perception and understanding of the universe. In this issue of PNAS, the molecular chemistry directly observed within the galaxy is discussed. For the most part, the description of the molecular transformations requires specific kinetic schemes rather than chemical thermodynamics. Ionization of the very abundant molecular hydrogen and atomic helium followed by their secondary reactions is discussed. The rich variety of organic species observed is a challenge for complete understanding. The role and nature of reactions involving grain surfaces as well as new spectroscopic observations of interstellar and circumstellar regions are topics presented in this special feature.

  11. Manufacturing footprint optimisation: a necessity for manufacturing network in changing business environment

    DEFF Research Database (Denmark)

    Yang, Cheng; Farooq, Sami; Johansen, John

    2010-01-01

    Facing the unpredictable financial crisis, optimising the footprint can be the biggest and most important transformation a manufacturer can undertake. In order to realise the optimisation, fundamental understanding on manufacturing footprint is required. Different elements of manufacturing...... footprint have been investigated independently in the existing literature. In this paper, for the purpose of relationship exploration between different elements, manufacturing footprints of three industrial companies are traced historically. Based on them, four reasons for the transformation...

  12. Assessing the Blue and Green Water Footprint of Lucerne for Milk Production in South Africa

    OpenAIRE

    Morne E. Scheepers; Henry Jordaan

    2016-01-01

    The Global Water Footprint Standard approach was used to calculate the volumetric blue and green water footprint indicator for lucerne production as important feed for dairy cows in a major lucerne production region in South Africa. The degree of sustainability of water use then was assessed by comparing water use to water availability for the region. The results show a volumetric water footprint indicator of 378 m3/tonne of lucerne. Of the total blue and green water footprint, 55% is green w...

  13. An alternative laser driven photodissociation mechanism of pyrrole via πσ*1∕S0 conical intersection.

    Science.gov (United States)

    Nandipati, K R; Lan, Z; Singh, H; Mahapatra, S

    2017-06-07

    A first principles quantum dynamics study of N-H photodissociation of pyrrole on the S 0 - 1 πσ * (A21) coupled electronic states is carried out with the aid of an optimally designed UV-laser pulse. A new photodissociation path, as compared to the conventional barrier crossing on the πσ*1 state, opens up upon electronic transitions under the influence of pump-dump laser pulses, which efficiently populate both the dissociation channels. The interplay of electronic transitions due both to vibronic coupling and the laser pulse is observed in the control mechanism and discussed in detail. The proposed control mechanism seems to be robust, and not discussed in the literature so far, and is expected to trigger future experiments on the πσ*1 photochemistry of molecules of chemical and biological importance. The design of the optimal pulses and their application to enhance the overall dissociation probability is carried out within the framework of optimal control theory. The quantum dynamics of the system in the presence of pulse is treated by solving the time-dependent Schrödinger equation in the semi-classical dipole approximation.

  14. An alternative laser driven photodissociation mechanism of pyrrole via π*1σ/S0 conical intersection

    Science.gov (United States)

    Nandipati, K. R.; Lan, Z.; Singh, H.; Mahapatra, S.

    2017-06-01

    A first principles quantum dynamics study of N-H photodissociation of pyrrole on the S0-1π σ*(A12) coupled electronic states is carried out with the aid of an optimally designed UV-laser pulse. A new photodissociation path, as compared to the conventional barrier crossing on the π*1σ state, opens up upon electronic transitions under the influence of pump-dump laser pulses, which efficiently populate both the dissociation channels. The interplay of electronic transitions due both to vibronic coupling and the laser pulse is observed in the control mechanism and discussed in detail. The proposed control mechanism seems to be robust, and not discussed in the literature so far, and is expected to trigger future experiments on the π*1σ photochemistry of molecules of chemical and biological importance. The design of the optimal pulses and their application to enhance the overall dissociation probability is carried out within the framework of optimal control theory. The quantum dynamics of the system in the presence of pulse is treated by solving the time-dependent Schrödinger equation in the semi-classical dipole approximation.

  15. Photodissociation dynamics of 2-chloro-6-nitrotoluene and nitrocyclopentane in gas phase: Laser-induced fluorescence detection of OH

    Science.gov (United States)

    Kawade, Monali N.; Saha, Ankur; Upadhyaya, Hari P.; Kumar, Awadhesh; Naik, Prakash D.

    2014-10-01

    Photodissociation of 2-chloro-6-nitrotoluene (ClNT) at 193, 248 and 266 nm and nitrocyclopentane (NCP) at 193 nm leads to the formation of OH, as detected by laser-induced fluorescence (LIF). The nascent OH produced from the photolysis of ClNT at all the wavelengths is vibrationally cold, with the Boltzmann type rotational state distributions. However, the nascent OH product from NCP is in the ground and vibrationally excited states with the measured average relative population in ν″ = 1 to that in ν″ = 0 of 0.12 ± 0.03, and these levels are characterized by rotational temperatures of 650 ± 180 K and 1570 ± 90 K, respectively. The translational energy partitioned in the OH fragment has been measured for photodissociation of both ClNT and NCP. On the basis of both the experimental results and the ground state molecular orbital (MO) calculations, a plausible mechanism for the OH formation has been proposed.

  16. Photodissociation dynamics of the methyl perthiyl radical at 248 and 193 nm using fast-beam photofragment translational spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Harrison, Aaron W.; Ryazanov, Mikhail; Sullivan, Erin N.; Neumark, Daniel M., E-mail: dneumark@berkeley.edu [Department of Chemistry, University of California, Berkeley, California 94720, USA and Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

    2016-07-14

    The photodissociation dynamics of the methyl perthiyl radical (CH{sub 3}SS) have been investigated using fast-beam coincidence translational spectroscopy. Methyl perthiyl radicals were produced by photodetachment of the CH{sub 3}SS{sup −} anion followed by photodissociation at 248 nm (5.0 eV) and 193 nm (6.4 eV). Photofragment mass distributions and translational energy distributions were measured at each dissociation wavelength. Experimental results show S atom loss as the dominant (96%) dissociation channel at 248 nm with a near parallel, anisotropic angular distribution and translational energy peaking near the maximal energy available to ground state CH{sub 3}S and S fragments, indicating that the dissociation occurs along a repulsive excited state. At 193 nm, S atom loss remains the major fragmentation channel, although S{sub 2} loss becomes more competitive and constitutes 32% of the fragmentation. The translational energy distributions for both channels are very broad at this wavelength, suggesting the formation of the S{sub 2} and S atom products in several excited electronic states.

  17. Water footprints of nations: water use by people as a function of their consumption pattern

    NARCIS (Netherlands)

    Hoekstra, Arjen Ysbert; Chapagain, Ashok

    2007-01-01

    The water footprint shows the extent of water use in relation to consumption of people. The water footprint of a country is defined as the volume of water needed for the production of the goods and services consumed by the inhabitants of the country. The internal water footprint is the volume of

  18. Air-source heat pump carbon footprints: HFC impacts and comparison to other heat sources

    International Nuclear Information System (INIS)

    Johnson, Eric P.

    2011-01-01

    European governments see that heat pumps could reduce carbon emissions in space- and hot-water heating. EU's Renewable Energy Directive designates heat pumps as renewable - eligible for various subsidies - if their carbon footprints are below an implied, average threshold. This threshold omits carbon generated by manufacture and emission of a heat-pump's fluorocarbon refrigerant. It also omits the footprint of the heat pump's hardware. To see if these omissions are significant, this study calculated carbon footprints of representative, residential heat pumps in the UK. Three findings emerged. First, in relation to power generation, which accounts for most of a heat-pump's greenhouse-gas emissions, fluorocarbons add another 20% to the footprint. Second, at UK efficiencies a heat-pump footprint (in kg CO 2 e emitted per kWh delivered) is comparable or higher than footprints of gaseous fuels used in heating. It is lower than the footprint of heating oil and far lower than the footprints of solid fuels. Third, production and disposal of a heat pump's hardware is relatively insignificant, accounting for only 2-3% of the overall heat-pump footprint. Sensitivities to the results were assessed: key factors are footprint of electricity generation, F-gas composition and leak rates and type of wall construction. - Research highlights: → Refrigerant emissions add 20% to a UK air-source heat pump's carbon footprint. → This contribution is so far ignored by regulations. → UK heat pump footprints are comparable to those of gaseous fuels.

  19. The Added Value of Water Footprint Assessment for National Water Policy: A Case Study for Morocco

    NARCIS (Netherlands)

    Schyns, Joseph Franciscus; Hoekstra, Arjen Ysbert

    2014-01-01

    A Water Footprint Assessment is carried out for Morocco, mapping the water footprint of different activities at river basin and monthly scale, distinguishing between surface- and groundwater. The paper aims to demonstrate the added value of detailed analysis of the human water footprint within a

  20. Post No Photos, Leave No Trace: Children's Digital Footprint Management Strategies

    Science.gov (United States)

    Buchanan, Rachel; Southgate, Erica; Smith, Shamus P.; Murray, Tiana; Noble, Brittany

    2017-01-01

    Given that today's children are prolific users of the internet, concern has been raised about the future impact of the digital footprints they are currently generating. Here, we report on the "Best Footprint Forward" project which utilised focus groups to investigate the digital footprint awareness of 33 children (ranging in age from 10…

  1. Radiation chemistry and bioradical chemistry

    International Nuclear Information System (INIS)

    Ferradini, C.

    1991-01-01

    Oxygen metabolism results, at the cellular level, in the formation of superoxyde radical O 2 - · and probably also of hydroxyl radical OH·. Other radical species can be produced from exogenous or endogenous molecules and nearly all of them have the possibility to react with oxygen giving peroxyradicals. Some of these transients play a role in various biological processes such as phagocytosis, inflammation or ischemy although the mechanisms invoked are poorly understood. Radiation chemistry is an invaluable tool for obtaining a quantitative view of these mechanisms. A description is given of this interaction [fr

  2. Mitigating climate change by minimising the carbon footprint and ...

    African Journals Online (AJOL)

    The analysis determines that lower scaled, spatially economical structures using low embodied energy materials will positively contribute to reduced carbon footprints and thus climate change mitigation strategies. The outcomes of the article also set a benchmark for prospective life-cycle assessments (LCA) and establish ...

  3. Measuring your water footprint: What's next in water strategy

    NARCIS (Netherlands)

    Hoekstra, Arjen Ysbert

    2008-01-01

    By now, carbon neutrality is such a catchphrase in the world of responsible business, it’s impossible to ignore the carbon footprint of a new product or service. But with the exception of a few companies like Coca-Cola, Nestlé and Suez, the concept of water neutrality, or measuring your water

  4. galstreams: Milky Way streams footprint library and toolkit

    Science.gov (United States)

    Mateu, Cecilia

    2017-11-01

    galstreams provides a compilation of spatial information for known stellar streams and overdensities in the Milky Way and includes Python tools for visualizing them. ASCII tables are also provided for quick viewing of the stream's footprints using TOPCAT (ascl:1101.010).

  5. Carbon footprint of construction using industrialised building system

    Science.gov (United States)

    Lim, P. Y.; Yahya, K.; Aminudin, E.; Zakaria, R.; Haron, Z.; Mohamad Zin, R.; Redzuan, A. A. H.

    2017-11-01

    Industrialised Building System (IBS) is more sustainable to the environment as compared to the conventional construction methods. However, the construction industry in Malaysia has low acceptance towards IBS due to the resistance to change and also lack of awareness towards sustainability development. Therefore, it is important to study the amount carbon footprint produced by IBS during its manufacturing and construction stage, and also the amount of carbon footprint produced by one meter square of gross floor area of IBS construction using Life Cycle Assessment (LCA) to ease future research through the comparison of the carbon footprint of IBS with the conventional building system. As a result, a case study on a residential type of construction in the vicinity of Johor Bahru, Malaysia was carried out to obtain the necessary data and result. From the data analysis, the amount of greenhouse gases (GHG) for a residential type IBS construction based on the raw materials and resources involved to manufacture and construct IBS components is 0.127 tonnes fossil CO2Eq per meter square. Raw material that contributed to the most amount of carbon footprint is Ordinary Portland Cement (OPC), followed by steel bars, autoclaved aerated blocks and diesel. The LCA data acquired will be very useful in implementing IBS in the residential type construction. As a result, the awareness towards sustainable construction using IBS can be improved.

  6. Water footprint assessment to inform water management and policy ...

    African Journals Online (AJOL)

    One method to inform decisions with respect to sustainable, efficient and equitable water allocation and use is water footprint assessment (WFA). This paper presents a preliminary WFA of South Africa (SA) based on data for the period 1996–2005. Crop production was found to contribute about 75% of the total water ...

  7. Water footprint of growing vegetables in selected smallholder ...

    African Journals Online (AJOL)

    Crop water footprint (WF) is the volume of fresh water used to produce a certain crop in all the steps in the production line. The CROPWAT model was used to calculate crop evapotranspiration, differentiating green and blue water in Zanyokwe (ZIS), Thabina (TIS) and Tugela Ferry (TFIS) Irrigation Schemes. Green beans ...

  8. Lebanese household carbon footprint: Measurements, analysis and challenges

    Science.gov (United States)

    Nasr, Rawad; Tall, Ibrahim; Nachabe, Nour; Chaaban, Farid

    2016-07-01

    The main purpose of this paper is to estimate the carbon footprint of a typical Lebanese household, and compare the results with international standards and trends. The estimation of this footprint will reflect the impact of the daily Lebanese household activities on the environment in terms of carbon dioxide emissions. The method used in estimating the carbon emissions is based on gathering the primary footprints from various household activities. Another proposed method that provides more accurate results is the estimation of emissions based on secondary footprint, which reflects the total emissions not only from the regular activities but also from a lifecycle perspective. Practical and feasible solutions were proposed to help reduce the amount of C02 emissions per household. This would lead to a better air quality, money savings, greenhouse gases emissions reduction and would ensure the sustainability and prosperity of future generations. A detailed survey was conducted in which the questions were focused mainly on energy, food, and transportation issues. The fourteen questions were addressed to one hundred families in different Lebanese regions coming from different social and economic backgrounds. This diversity would constitute a reflective sample of the actual Lebanese society, allowing us to extrapolate the gathered results on a national level.

  9. Effects of Globalisation on Carbon Footprints of Products

    DEFF Research Database (Denmark)

    Herrmann, Ivan Tengbjerg; Hauschild, Michael Zwicky

    2009-01-01

    Outsourcing of production from the industrialised countries to the newly industrialised economies holds the potential to increase wealth in both places, but what are the environmental costs of the globalised manufacturing systems? This paper looks into the changes in carbon footprint...

  10. Application of the DIY carbon footprint calculator to a wastewater ...

    African Journals Online (AJOL)

    ... own 'green' energy by using anaerobically produced methane gas as a green energy alternative. This investigation demonstrates how the baseline carbon footprint of a wastewater treatment works can be reduced by considering viable options such as biogas to power generation, process re-design and drives to improve ...

  11. Carbon footprint of urban source separation for nutrient recovery.

    Science.gov (United States)

    Kjerstadius, H; Bernstad Saraiva, A; Spångberg, J; Davidsson, Å

    2017-07-15

    Source separation systems for the management of domestic wastewater and food waste has been suggested as more sustainable sanitation systems for urban areas. The present study used an attributional life cycle assessment to investigate the carbon footprint and potential for nutrient recovery of two sanitation systems for a hypothetical urban area in Southern Sweden. The systems represented a typical Swedish conventional system and a possible source separation system with increased nutrient recovery. The assessment included the management chain from household collection, transport, treatment and final return of nutrients to agriculture or disposal of the residuals. The results for carbon footprint and nutrient recovery (phosphorus and nitrogen) concluded that the source separation system could increase nutrient recovery (0.30-0.38 kg P capita -1 year -1 and 3.10-3.28 kg N capita -1 year -1 ), while decreasing the carbon footprint (-24 to -58 kg CO 2 -eq. capita -1 year -1 ), compared to the conventional system. The nutrient recovery was increased by the use of struvite precipitation and ammonium stripping at the wastewater treatment plant. The carbon footprint decreased, mainly due to the increased biogas production, increased replacement of mineral fertilizer in agriculture and less emissions of nitrous oxide from wastewater treatment. In conclusion, the study showed that source separation systems could potentially be used to increase nutrient recovery from urban areas, while decreasing the climate impact. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Computers and the Environment: Minimizing the Carbon Footprint

    Science.gov (United States)

    Kaestner, Rich

    2009-01-01

    Computers can be good and bad for the environment; one can maximize the good and minimize the bad. When dealing with environmental issues, it's difficult to ignore the computing infrastructure. With an operations carbon footprint equal to the airline industry's, computer energy use is only part of the problem; everyone is also dealing with the use…

  13. Carbon footprint of the Danish electricity transmission and distribution systems

    DEFF Research Database (Denmark)

    Turconi, Roberto; Astrup, Thomas Fruergaard

    . The purpose was to evaluate the potential importance of environmental impacts associated with T&D in current and future electricity systems. Including the emissions from electricity T&D is needed to provide a full carbon footprint of electricity systems, and is essential to properly assess the environmental...

  14. Water Footprint and Virtual Water Trade of Brazil

    NARCIS (Netherlands)

    da Silva, Vicente de Paulo R.; de Oliveira, Sonaly D.; Hoekstra, Arjen Ysbert; Neto, Jose Dantas; Campos, João Hugo B.C.; Braga, Celia C.; Araújo, Lincoln Eloi; Oliveira Aleixo, Danilo; de Brito, Jose Ivaldo B.; de Souza, Marcio Dionisio; de Holanda, Romildo M.

    2016-01-01

    Freshwater scarcity has increased at an alarming rate worldwide; improved water management plays a vital role in increasing food production and security. This study aims to determine the water footprint of Brazil’s national food consumption, the virtual water flows associated with international

  15. Sustainability of the water footprint of the Spanish pork industry

    NARCIS (Netherlands)

    de Miguel, Ángel; Hoekstra, Arjen Ysbert; Garcia-Calvo, Eloy

    2015-01-01

    Around 92% of the humanity's footprint (WF) relates to the agricultural sector, and a considerable proportion of this is associated with animal farming. In Spain, the swine sector accounts for 11% of agricultural output in economic terms and makes substantial demands on freshwater resources. In this

  16. Off-gas treatment carbon footprint calculator : form and function

    Energy Technology Data Exchange (ETDEWEB)

    Kessell, L. [Good EarthKeeping Organization Inc., Corona, CA (United States); Squire, J.; Crosby, K. [Haley and Aldrich Inc., Boston, MA (United States)

    2008-07-01

    Carbon footprinting is the measurement of the impact on the environment in terms of the amount of greenhouse gases produced, measured in units of carbon dioxide released directly and indirectly by an individual, organization, process, event or product. This presentation discussed an off-gas treatment carbon footprint calculator. The presentation provided a review of off-gas treatment technologies and presented a carbon footprint model. The model included: form and function; parameters; assumptions; calculations; and off-gas treatment applications. Parameters of the model included greenhouse gases listed in the Kyoto Protocol to the United Nations Framework Convention on Climate Change, such as carbon dioxide, methane, nitrous oxide, sulfur hexafluoride, hydrofluorocarbons, and perfluorocarbons. Assumptions of the model included stationary combustion emissions; mobile combustion emissions; indirect emissions; physical or chemical processing emissions; fugitive emissions; and de minimus emissions. The presentation also examined resource conservation and discussed three greenhouse gas footprint case studies. It was concluded that the model involved a calculator with standard calculations with clearly defined assumptions with boundaries. tabs., figs.

  17. Antagonism in the carbon footprint between beef and dairy ...

    African Journals Online (AJOL)

    The higher increase in production (milk) of intensive dairy cows, compared to the increase in production (calf weight) of intensive beef cows, explains the antagonism in the carbon footprint between different beef and dairy production systems. Unfortunately, carbon sequestration estimates have been neglected and thus the ...

  18. Burning water: The water footprint of biofuel-based transport

    NARCIS (Netherlands)

    Gerbens-Leenes, Winnie; Hoekstra, Arjen Ysbert

    2010-01-01

    The trend towards substitution of conventional transport fuels by biofuels requires additional water. The EU aims to replace 10 percent of total transport fuels by biofuels by 2020. This study calculates the water footprint (WF) of different transport modes using bio-ethanol, biodiesel or

  19. The water footprint of biofuel-based transport

    NARCIS (Netherlands)

    Gerbens-Leenes, Winnie; Hoekstra, Arjen Ysbert

    2011-01-01

    The EU target to replace 10 percent of transport fuels by renewables by 2020 requires additional water. This study calculates water footprints (WFs) of transport modes using first generation bio-ethanol, biodiesel or bio-electricity and of European transport if 10 percent of transport fuels is

  20. Fundamentals of nuclear chemistry

    International Nuclear Information System (INIS)

    Majer, K.

    1982-01-01

    The textbook is a Czech-to-German translation of the second revised edition and covers the subject under the headings: general nuclear chemistry, methods of nuclear chemistry, preparative nuclear chemistry, analytical nuclear chemistry, and applied chemistry. The book is especially directed to students

  1. Advanced entry guidance algorithm with landing footprint computation

    Science.gov (United States)

    Leavitt, James Aaron

    The design and performance evaluation of an entry guidance algorithm for future space transportation vehicles is presented. The algorithm performs two functions: on-board trajectory planning and trajectory tracking. The planned longitudinal path is followed by tracking drag acceleration, as is done by the Space Shuttle entry guidance. Unlike the Shuttle entry guidance, lateral path curvature is also planned and followed. A new trajectory planning function for the guidance algorithm is developed that is suitable for suborbital entry and that significantly enhances the overall performance of the algorithm for both orbital and suborbital entry. In comparison with the previous trajectory planner, the new planner produces trajectories that are easier to track, especially near the upper and lower drag boundaries and for suborbital entry. The new planner accomplishes this by matching the vehicle's initial flight path angle and bank angle, and by enforcing the full three-degree-of-freedom equations of motion with control derivative limits. Insights gained from trajectory optimization results contribute to the design of the new planner, giving it near-optimal downrange and crossrange capabilities. Planned trajectories and guidance simulation results are presented that demonstrate the improved performance. Based on the new planner, a method is developed for approximating the landing footprint for entry vehicles in near real-time, as would be needed for an on-board flight management system. The boundary of the footprint is constructed from the endpoints of extreme downrange and crossrange trajectories generated by the new trajectory planner. The footprint algorithm inherently possesses many of the qualities of the new planner, including quick execution, the ability to accurately approximate the vehicle's glide capabilities, and applicability to a wide range of entry conditions. Footprints can be generated for orbital and suborbital entry conditions using a pre

  2. Understanding Our Energy Footprint: Undergraduate Chemistry Laboratory Investigation of Environmental Impacts of Solid Fossil Fuel Wastes

    Science.gov (United States)

    Berger, Michael; Goldfarb, Jillian L.

    2017-01-01

    Engaging undergraduates in the environmental consequences of fossil fuel usage primes them to consider their own anthropogenic impact, and the benefits and trade-offs of converting to renewable fuel strategies. This laboratory activity explores the potential contaminants (both inorganic and organic) present in the raw fuel and solid waste…

  3. Cyclodextrin chemistry

    International Nuclear Information System (INIS)

    Khan, M.Z.; Chuaqui, C.A.

    1990-05-01

    The chemistry of cyclodextrins was studied. This study included synthesising some cyclodextrin derivatives, preparing selected inclusion complexes with cyclodextrin and investigating the effects of gamma irradiation on cyclodextrins and certain linear oligosaccharides. This report presents a brief review of the structure and properties of cyclodextrins, the synthesis of cyclodextrin derivatives, their complexation and applications. This is followed by a description of the synthesis of some cyclodextrin derivatives and the preparation of inclusion complexes of cyclodextrin with some organic compounds. Finally, the effects of gamma irradiation on cyclodextrins, some of their derivatives and certain structurally related carbohydrates are discussed. The gamma irradiation studies were carried out for two reasons: to study the effects of gamma irradiation on cyclodextrins and their derivatives; and to investigate selectivity during the gamma irradiation of cyclodextrin derivatives

  4. Astronomical chemistry.

    Science.gov (United States)

    Klemperer, William

    2011-01-01

    The discovery of polar polyatomic molecules in higher-density regions of the interstellar medium by means of their rotational emission detected by radioastronomy has changed our conception of the universe from essentially atomic to highly molecular. We discuss models for molecule formation, emphasizing the general lack of thermodynamic equilibrium. Detailed chemical kinetics is needed to understand molecule formation as well as destruction. Ion molecule reactions appear to be an important class for the generally low temperatures of the interstellar medium. The need for the intrinsically high-quality factor of rotational transitions to definitively pin down molecular emitters has been well established by radioastronomy. The observation of abundant molecular ions both positive and, as recently observed, negative provides benchmarks for chemical kinetic schemes. Of considerable importance in guiding our understanding of astronomical chemistry is the fact that the larger molecules (with more than five atoms) are all organic.

  5. Reburning chemistry

    International Nuclear Information System (INIS)

    Kilpin, P.; Hupa, M.; Glarborg, P.

    1992-01-01

    No reduction chemistry in natural gas (methane) reburning was studied using detailed kinetic modeling. A reaction set including 225 reversible elementary gas-phase reactions and 48 chemical species was applied to an ideal plug flow reactor, and the most important reactions leading to NO reduction were identified and quantified for a number of conditions relevant for natural gas reburning. In addition, the influence of different process parameters on the NO reduction was investigated in the reburn zone and burn-out zone, respectively. Further, comparison of the calculations to available laboratory-scale data on reburning is made. In this paper, the impact of various fluid dynamic, mixing, and chemical effects---not accounted for in the calculations---on the NO reduction and the optimum reburning conditions predicted is discussed

  6. Combustion chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Brown, N.J. [Lawrence Berkeley Laboratory, CA (United States)

    1993-12-01

    This research is concerned with the development and use of sensitivity analysis tools to probe the response of dependent variables to model input variables. Sensitivity analysis is important at all levels of combustion modeling. This group`s research continues to be focused on elucidating the interrelationship between features in the underlying potential energy surface (obtained from ab initio quantum chemistry calculations) and their responses in the quantum dynamics, e.g., reactive transition probabilities, cross sections, and thermal rate coefficients. The goals of this research are: (i) to provide feedback information to quantum chemists in their potential surface refinement efforts, and (ii) to gain a better understanding of how various regions in the potential influence the dynamics. These investigations are carried out with the methodology of quantum functional sensitivity analysis (QFSA).

  7. The Human Footprint in Mexico: Physical Geography and Historical Legacies

    Science.gov (United States)

    Ortega-Rubio, Alfredo; Kolb, Melanie; Bezaury Creel, Juan E.

    2015-01-01

    Using publicly available data on land use and transportation corridors we calculated the human footprint index for the whole of Mexico to identify large-scale spatial patterns in the anthropogenic transformation of the land surface. We developed a map of the human footprint for the whole country and identified the ecological regions that have most transformed by human action. Additionally, we analyzed the extent to which (a) physical geography, expressed spatially in the form of biomes and ecoregions, compared to (b) historical geography, expressed as the spatial distribution of past human settlements, have driven the patterns of human modification of the land. Overall Mexico still has 56% of its land surface with low impact from human activities, but these areas are not evenly distributed. The lowest values are on the arid north and northwest, and the tropical southeast, while the highest values run along the coast of the Gulf of Mexico and from there inland along an east-to-west corridor that follows the Mexican transversal volcanic ranges and the associated upland plateau. The distribution of low- and high footprint areas within ecoregions forms a complex mosaic: the generally well-conserved Mexican deserts have some highly transformed agro-industrial areas, while many well-conserved, low footprint areas still persist in the highly-transformed ecoregions of central Mexico. We conclude that the spatial spread of the human footprint in Mexico is both the result of the limitations imposed by physical geography to human development at the biome level, and, within different biomes, of a complex history of past civilizations and technologies, including the 20th Century demographic explosion but also the spatial pattern of ancient settlements that were occupied by the Spanish Colony. PMID:25803839

  8. The human footprint in Mexico: physical geography and historical legacies.

    Science.gov (United States)

    González-Abraham, Charlotte; Ezcurra, Exequiel; Garcillán, Pedro P; Ortega-Rubio, Alfredo; Kolb, Melanie; Bezaury Creel, Juan E

    2015-01-01

    Using publicly available data on land use and transportation corridors we calculated the human footprint index for the whole of Mexico to identify large-scale spatial patterns in the anthropogenic transformation of the land surface. We developed a map of the human footprint for the whole country and identified the ecological regions that have most transformed by human action. Additionally, we analyzed the extent to which (a) physical geography, expressed spatially in the form of biomes and ecoregions, compared to (b) historical geography, expressed as the spatial distribution of past human settlements, have driven the patterns of human modification of the land. Overall Mexico still has 56% of its land surface with low impact from human activities, but these areas are not evenly distributed. The lowest values are on the arid north and northwest, and the tropical southeast, while the highest values run along the coast of the Gulf of Mexico and from there inland along an east-to-west corridor that follows the Mexican transversal volcanic ranges and the associated upland plateau. The distribution of low- and high footprint areas within ecoregions forms a complex mosaic: the generally well-conserved Mexican deserts have some highly transformed agro-industrial areas, while many well-conserved, low footprint areas still persist in the highly-transformed ecoregions of central Mexico. We conclude that the spatial spread of the human footprint in Mexico is both the result of the limitations imposed by physical geography to human development at the biome level, and, within different biomes, of a complex history of past civilizations and technologies, including the 20th Century demographic explosion but also the spatial pattern of ancient settlements that were occupied by the Spanish Colony.

  9. Footprinting of Chlorella virus DNA ligase bound at a nick in duplex DNA.

    Science.gov (United States)

    Odell, M; Shuman, S

    1999-05-14

    The 298-amino acid ATP-dependent DNA ligase of Chlorella virus PBCV-1 is the smallest eukaryotic DNA ligase known. The enzyme has intrinsic specificity for binding to nicked duplex DNA. To delineate the ligase-DNA interface, we have footprinted the enzyme binding site on DNA and the DNA binding site on ligase. The size of the exonuclease III footprint of ligase bound a single nick in duplex DNA is 19-21 nucleotides. The footprint is asymmetric, extending 8-9 nucleotides on the 3'-OH side of the nick and 11-12 nucleotides on the 5'-phosphate side. The 5'-phosphate moiety is essential for the binding of Chlorella virus ligase to nicked DNA. Here we show that the 3'-OH moiety is not required for nick recognition. The Chlorella virus ligase binds to a nicked ligand containing 2',3'-dideoxy and 5'-phosphate termini, but cannot catalyze adenylation of the 5'-end. Hence, the 3'-OH is important for step 2 chemistry even though it is not itself chemically transformed during DNA-adenylate formation. A 2'-OH cannot substitute for the essential 3'-OH in adenylation at a nick or even in strand closure at a preadenylated nick. The protein side of the ligase-DNA interface was probed by limited proteolysis of ligase with trypsin and chymotrypsin in the presence and absence of nicked DNA. Protease accessible sites are clustered within a short segment from amino acids 210-225 located distal to conserved motif V. The ligase is protected from proteolysis by nicked DNA. Protease cleavage of the native enzyme prior to DNA addition results in loss of DNA binding. These results suggest a bipartite domain structure in which the interdomain segment either comprises part of the DNA binding site or undergoes a conformational change upon DNA binding. The domain structure of Chlorella virus ligase inferred from the solution experiments is consistent with the structure of T7 DNA ligase determined by x-ray crystallography.

  10. Trends and Consumption Structures of China’s Blue and Grey Water Footprint

    Directory of Open Access Journals (Sweden)

    Huixiao Wang

    2018-04-01

    Full Text Available Water footprint has become a common method to study the water resources utilization in recent years. By using input–output analysis and dilution theory, the internal water footprint, blue water footprint and grey water footprint of China from 2002 to 2012 were estimated, and the consumption structure of water footprint and virtual water trade were analyzed. The results show: (1 From 2002 to 2012, the average annual internal water footprint was 3.83 trillion m3 in China, of which the blue water footprint was 0.25 trillion m3, and the grey water footprint was 3.58 trillion m3 (with Grade III water standard accounting; both the internal water footprint and grey water footprint experienced decreasing trends from 2002 to 2012, except for a dramatic increase in 2010; (2 Average annual virtual blue water footprint was the greatest in agriculture (39.2%, while tertiary industry (27.5% and food and tobacco processing (23.7% were the top two highest for average annual virtual grey water footprint; (3 Virtual blue water footprint in most sectors showed increasing trends due to the increase of final demand, while virtual grey water footprint in most sectors showed decreasing trends due to the decreases of total return water coefficients and conversion coefficients of virtual grey water footprint; (4 For water resources, China was self-reliant: the water used for producing the products and services to meet domestic consumption was taken domestically; meanwhile, China exported virtual water to other countries, which aggravated the water stress in China.

  11. Reducing Students' Carbon Footprints Using Personal Carbon Footprint Management System Based on Environmental Behavioural Theory and Persuasive Technology

    Science.gov (United States)

    Lin, Shyh-ming

    2016-01-01

    This study applied environmental behavioural theories to develop a personal carbon footprint management system and used persuasive technology to implement it. The system serves as an educational system to improve the determinants of students' low-carbon behaviours, to promote low-carbon concepts and to facilitate their carbon management. To assess…

  12. Why Teach Environmental Chemistry?

    Science.gov (United States)

    Gardner, Marjorie H.

    1974-01-01

    Discusses the importance of teaching environmental chemistry in secondary school science classes, and outlines five examples of environmental chemistry problems that focus on major concepts of chemistry and have critical implications for human survival and well-being. (JR)

  13. Picosecond real time study of the bimolecular reaction O(3P)+C2H4 and the unimolecular photodissociation of CH3CHO and H2CO

    Science.gov (United States)

    Abou-Zied, Osama K.; McDonald, J. Douglas

    1998-07-01

    The bimolecular reaction of O(3P) with ethylene and the unimolecular photodissociation of acetaldehyde and formaldehyde have been studied using a picosecond pump/probe technique. The bimolecular reaction was initiated in a van der Waals dimer precursor, C2H4ṡNO2, and the evolution of the vinoxy radical product monitored by laser-induced fluorescence. The NO2 constituent of the complex was photodissociated at 266 nm. The triplet oxygen atom then attacks a carbon atom of C2H4 to form a triplet diradical (CH2CH2O) which subsequently dissociates to vinoxy (CH2CHO) and H. The rise time of vinoxy radical production was measured to be 217 (+75-25) ps. RRKM theory was applied and a late high exit barrier was invoked in order to fit the measured rise time. The structure and binding energy of the van der Waals complex have been modeled using Lennard-Jones type potentials and the results were compared with other systems. The unimolecular side of the potential energy surfaces of this reaction has been investigated by photodissociating acetaldehyde at the same pump energy of 266 nm. The resulting photoproducts, acetyl radical (CH3CO) and formyl radical (HCO), have been monitored by resonance enhanced multiphoton ionization (REMPI) combined with a time-of-flight mass spectrometer. The similarity in the measured evolution times of both radicals indicates the same photodissociation pathway of the parent molecule. The photodissociation rate of acetaldehyde is estimated from RRKM theory to be very fast (3×1012s-1). The T1←S1 intersystem crossing (ISC) rate is found to be the rate determining step to photodissociation and increases with energy. The REMPI mechanism for the production of CH3CO+ is proposed to be the same as that of HCO+(2+1). The HCO product from the photodissociation of formaldehyde at 266 nm reveals a faster T1←S1 ISC rate than in acetaldehyde.

  14. Environmental chemistry. Seventh edition

    Energy Technology Data Exchange (ETDEWEB)

    Manahan, S.E. [Univ. of Missouri, Columbia, MO (United States)

    1999-11-01

    This book presents a basic understanding of environmental chemistry and its applications. In addition to providing updated materials in this field, the book emphasizes the major concepts essential to the practice of environmental chemistry. Topics of discussion include the following: toxicological chemistry; toxicological chemistry of chemical substances; chemical analysis of water and wastewater; chemical analysis of wastes and solids; air and gas analysis; chemical analysis of biological materials and xenobiotics; fundamentals of chemistry; and fundamentals of organic chemistry.

  15. Photodissociation of aniline N–H bond in clusters of different nature

    Czech Academy of Sciences Publication Activity Database

    Poterya, Viktoriya; Nachtigallová, Dana; Lengyel, Jozef; Fárník, Michal

    2015-01-01

    Roč. 17, č. 38 (2015), s. 25004-25013 ISSN 1463-9076 R&D Projects: GA ČR GA14-14082S Institutional support: RVO:61388955 ; RVO:61388963 Keywords : NONADIABATIC COUPLING TERMS * MR-CI LEVEL * PHOTOEXCITED ANILIN E Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.449, year: 2015

  16. Photodissociation dynamics of ethanethiol in clusters: complementary information from velocity map imaging, mass spectrometry and calculations

    Czech Academy of Sciences Publication Activity Database

    Svrčková, Pavla; Pysanenko, Andriy; Lengyel, Jozef; Rubovič, Peter; Kočišek, Jaroslav; Poterya, Viktoriya; Slavíček, Petr; Fárník, Michal

    2015-01-01

    Roč. 17, č. 39 (2015), s. 25734-25741 ISSN 1463-9076 R&D Projects: GA ČR GA14-14082S; GA ČR GA14-08937S Institutional support: RVO:61388955 Keywords : POTENTIAL-ENERGY SURFACES * METHYL MERCAPTAN * CONICAL INTERSECTIONS Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.449, year: 2015

  17. USSR Report Chemistry

    National Research Council Canada - National Science Library

    1986-01-01

    Contents: Adsorption, Chemistry,Alkaloids, Analytical Chemistry, Catalysis,Chemical Industry,,Coal Gasification, Combustion, Electrochemistry,Explosives and Explosions, Fertilizers, Free Radicals, Inorganic...

  18. Water footprint assessment of oil palm in Malaysia: A preliminary study

    Science.gov (United States)

    Muhammad-Muaz, A.; Marlia, M. H.

    2014-09-01

    This study evaluates the water footprint of growing oil palm in Malaysia based on the water footprint method. The crop water use was determined using the CROPWAT 8.0 model developed by the Land and Water Development Division of FAO. The total water footprint for growing oil palm is 243 m3/ton. The result of this study showed that the green water footprint is 1.5 orders of magnitude larger compared to the blue water footprint. Besides providing updated status of total water used from the oil palm plantation, our result also shows that this baseline information helps in identifying which areas need to be conserved and what type of recommendation that should be drawn. As the results of the water footprint can differ between locations, the inclusion of local water stress index should be considered in the calculation of water footprint.

  19. Study of Biometric Identification Method Based on Naked Footprint

    Directory of Open Access Journals (Sweden)

    Raji Rafiu King

    2013-10-01

    Full Text Available The scale of deployment of biometric identity-verification systems has recently seen an enormous increase owing to the need for more secure and reliable way of identifying people. Footprint identification which can be defined as the measurement of footprint features for recognizing the identity of a user has surfaced recently. This study is based on a biometric personal identification method using static footprint features viz. friction ridge / texture and foot shape / silhouette. To begin with, naked footprints of users are captured; images then undergo pre processing followed by the extraction of two features; shape using Gradient Vector Flow (GVF) snake model and minutiae extraction respectively. Matching is then effected based on these two features followed by a fusion of these two results for either a reject or accept decision. Our shape matching feature is based on cosine similarity while the texture one is based on miniature score matching. The results from our research establish that the naked footprint is a credible biometric feature as two barefoot impressions of an individual match perfectly while that of two different persons shows a great deal of dissimilarity. Normal 0 false false false IN X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Doi: 10.12777/ijse.5.2.29-35 How to cite this article: King

  20. The role of water-vapour photodissociation on the formation of a deep minimum in mesopause ozone

    Directory of Open Access Journals (Sweden)

    I. M. Vardavas

    1998-02-01

    Full Text Available A one-dimensional atmospheric photochemical model with an altitude grid of about 1.5 km was used to examine the structure of the global mean vertical ozone profile and its night-time-to-daytime variation in the upper atmosphere. Two distinct ozone layers are predicted, separated by a sharp drop in the ozone concentration near the mesopause. This naturally occurring mesopause ozone deep minimum is primarily produced by the rapid increase in the destruction of water vapour, and hence increase in HOx, at altitudes between 80 and 85 km, a region where water-vapour photodissociation by ultraviolet radiation of the solar Lyman-alpha line is significant, and where the supply of water vapour is maintained by methane oxidation even for very dry conditions at the tropospheric-stratospheric exchange region. The model indicates that the depth of the mesopause ozone minimum is limited by the efficiency with which inactive molecular hydrogen is produced, either by the conversion of atomic hydrogen to molecular hydrogen via one of the reaction channels of H with HO2, or by Lyman-alpha photodissociation of water vapour via the channel that leads to the production of molecular hydrogen. The ozone concentration rapidly recovers above 85 km due to the rapid increase in O produced by the photodissociation of O2 by absorption of ultraviolet solar radiation in the Schumann-Runge bands and continuum. Above 90 km, there is a decrease in ozone due to photolysis as the production of ozone through the three-body recombination of O2 and O becomes slower with decreasing pressure. The model also predicts two peaks in the night-time/daytime ozone ratio, one near 75 km and the other near 110 km, plus a strong peak in the night-time/daytime ratio of OH near 110 km. Recent observational evidence supports the predictions of the model.Key words. Atmospheric composition and structure · Middle atmosphere · Thermosphere · Transmission and scattering of radiation

  1. Water chemistry

    International Nuclear Information System (INIS)

    Hofstetter, K.J.; Baston, V.F.

    1986-01-01

    Prior to the accident, the coolants in the primary and secondary systems were within normal chemistry specifications for an operating pressurized water reactor with once-through steam generators. During and immediately after the accident, additional boric acid and sodium hydroxide were added to the primary coolant for control of criticality and radioiodine solubility. A primary to secondary leak developed contaminating the water in one steam generator. For about 5 years after the accident, the primary coolant was maintained at 3800 +. 100 ppm boron and 1000 +. 100 ppm sodium concentrations. Dissolved oxygen was maintained 7.5, corrosion caused by increased dissolved oxygen levels (up to 8 ppm) and higher chloride ion content (up to 5 ppm) is minimized. Chemical control of dissolved oxygen was discontinued and the coolant was processed. Prior to removal of the reactor vessel head, the boron concentration in the coolant was increased to ≅ 5000 ppm to support future defueling operations. Decontamination of the accident generated water is described in terms of contaminated water management. In addition, the decontamination and chemical lay-up conditions for the secondary system are presented along with an overview of chemical management at TMI-2

  2. Migration chemistry

    International Nuclear Information System (INIS)

    Carlsen, L.

    1992-05-01

    Migration chemistry, the influence of chemical -, biochemical - and physico-chemical reactions on the migration behaviour of pollutants in the environment, is an interplay between the actual natur of the pollutant and the characteristics of the environment, such as pH, redox conditions and organic matter content. The wide selection of possible pollutants in combination with varying geological media, as well as the operation of different chemical -, biochemical - and physico-chemical reactions compleactes the prediction of the influence of these processes on the mobility of pollutants. The report summarizes a wide range of potential pollutants in the terrestrial environment as well as a variety of chemical -, biochemical - and physico-chemical reactions, which can be expected to influence the migration behaviour, comprising diffusion, dispersion, convection, sorption/desorption, precipitation/dissolution, transformations/degradations, biochemical reactions and complex formation. The latter comprises the complexation of metal ions as well as non-polar organics to naturally occurring organic macromolecules. The influence of the single types of processes on the migration process is elucidated based on theoretical studies. The influence of chemical -, biochemical - and physico-chemical reactions on the migration behaviour is unambiguous, as the processes apparently control the transport of pollutants in the terrestrial environment. As the simple, conventional K D concept breaks down, it is suggested that the migration process should be described in terms of the alternative concepts chemical dispersion, average-elution-time and effective retention. (AB) (134 refs.)

  3. Management options to reduce the carbon footprint of livestock products

    DEFF Research Database (Denmark)

    Hermansen, John Erik; Kristensen, Troels

    2011-01-01

    Livestock products carry a large carbon footprint compared with other foods, and thus there is a need to focus on how to reduce it. The major contributing factors are emissions related to feed use and manure handling as well as the nature of the land required to produce the feed in question. We can....... Basically, it is important to make sure that all beneficial interactions in the livestock system are optimized instead of focusing only on animal productivity. There is an urgent need to arrive at a sound framework for considering the interaction between land use and carbon footprints of foods....... conclude that the most important mitigation options include - better feed conversion at the system level, - use of feeds that increase soil carbon sequestration versus carbon emission, - ensure that the manure produced substitutes for synthetic fertilizer, and - use manure for bio-energy production...

  4. Morphing of Building Footprints Using a Turning Angle Function

    Directory of Open Access Journals (Sweden)

    Jingzhong Li

    2017-06-01

    Full Text Available We study the problem of morphing two polygons of building footprints at two different scales. This problem frequently occurs during the continuous zooming of interactive maps. The ground plan of a building footprint on a map has orthogonal characteristics, but traditional morphing methods cannot preserve these geographic characteristics at intermediate scales. We attempt to address this issue by presenting a turning angle function-based morphing model (TAFBM that can generate polygons at an intermediate scale with an identical turning angle for each side. Thus, the orthogonal characteristics can be preserved during the entire interpolation. A case study demonstrates that the model yields good results when applied to data from a building map at various scales. During the continuous generalization, the orthogonal characteristics and their relationships with the spatial direction and topology are well preserved.

  5. Pressure and temperature-dependent quantum yields for the photodissociation of acetone between 279 and 327.5 nm

    Science.gov (United States)

    Blitz, M. A.; Heard, D. E.; Pilling, M. J.; Arnold, S. R.; Chipperfield, M. P.

    2004-03-01

    The photodissociation of acetone has been studied over the wavelength (λ) range 279-327.5 nm as a function of temperature (T) and pressure (p) using a spectroscopic method to monitor the acetyl (CH3CO) radical fragment. Above 310 nm the quantum yield (QY) is substantially smaller than previous measurements, and decreases with T. The QYs for production of CH3CO + CH3 and CH3 + CH3 + CO have been parameterised as a function of λ, p and T and used to calculate the altitude dependence of the photolysis frequency. In the upper troposphere (UT) the acetone photolysis lifetime is a factor of 2.5-10 longer, dependent upon latitude and season, than if the previously recommended QYs are used.

  6. Photodissociation of acrylonitrile at 193 nm: A photofragment translational spectroscopy study using synchrotron radiation for product photoionization

    International Nuclear Information System (INIS)

    Blank, D.A.; Suits, A.G.; Lee, Y.T.; North, S.W.; Hall, G.E.

    1998-01-01

    We have investigated the photodissociation of acrylonitrile (H 2 CCHCN) at 193 nm using the technique of photofragment translational spectroscopy. The experiments were performed at the Chemical Dynamics Beamline at the Advanced Light Source and used tunable vacuum ultraviolet synchrotron radiation for product photoionization. We have identified four primary dissociation channels including atomic and molecular hydrogen elimination, HCN elimination, and CN elimination. There is significant evidence that all of the dissociation channels occur on the ground electronic surface following internal conversion from the initially optically prepared state. The product translational energy distributions reflect near statistical simple bond rupture for the radical dissociation channels, while substantial recombination barriers mediate the translational energy release for the two molecular elimination channels. Photoionization onsets have provided additional insight into the chemical identities of the products and their internal energy content. copyright 1998 American Institute of Physics

  7. Author Correction: The carbon footprint of global tourism

    Science.gov (United States)

    Lenzen, Manfred; Sun, Ya-Yen; Faturay, Futu; Ting, Yuan-Peng; Geschke, Arne; Malik, Arunima

    2018-06-01

    In the version of this Article originally published, in the penultimate paragraph of the section "Gas species and supply chains", in the sentence "In this assessment, the contribution of air travel emissions amounts to 20% (0.9 GtCO2e) of tourism's global carbon footprint..." the values should have read "12% (0.55 GtCO2e)"; this error has now been corrected, and Supplementary Table 9 has been amended to clarify this change.

  8. The footprint of urban heat island effect in China

    Science.gov (United States)

    Decheng Zhou; Shuqing Zhao; Liangxia Zhang; Ge Sun; Yongqiang Liu

    2015-01-01

    Urban heat island (UHI) is one major anthropogenic modification to the Earth system that transcends its physical boundary. Using MODIS data from 2003 to 2012, we showed that the UHI effect decayed exponentially toward rural areas for majority of the 32 Chinese cities. We found an obvious urban/ rural temperature “cliff”, and estimated that the footprint of UHI effect (...

  9. Guilt by Association-Based Discovery of Botnet Footprints

    Science.gov (United States)

    2010-11-01

    our fast flux database using our Fast Flux Monitor ( FFM ); a Web service application designed to detect whether a domain exhibits fast flux (FF) or...double flux (DF) behaviour. The primary technical components of FFM include: (1) sensors which perform real-time detection of FF service networks...sensors for our FFM active sensors: (1) FF Activity Index, (2) Footprint Index, and (3) Time To Live (TTL), and (4) Guilt by Association Score. In

  10. Carbon footprint of apple and pear : orchards, storage and distribution

    OpenAIRE

    Figueiredo, F.; Castanheira, E.G.; Feliciano, M.; Rodrigues, M.A.; Peres, A.; Maia, F.; Ramos, A.; Carneiro, J.P.; Coroama, V.C.; Freire, F.

    2013-01-01

    Apple and pear represent 51% of fresh fruit orchards in Portugal. This paper presents a life-cycle (LC) greenhouse gas (GHG) assessment (so-called carbon footprint) of 3 apple and 1 pear Portuguese production systems. An LC model and inventory were implemented, encompassing the farm stage (cultivation of fruit trees in orchards), storage and distribution (transport to retail). The functional unit considered in this study was 1 kg of distributed fruit (at retail). Four different LC inventories...

  11. Genomic footprinting in mammalian cells with ultraviolet light

    International Nuclear Information System (INIS)

    Becker, M.M.; Wang, Z.; Grossmann, G.; Becherer, K.A.

    1989-01-01

    A simple and accurate genomic primer extension method has been developed to detect ultraviolet footprinting patterns of regulatory protein-DNA interactions in mammalian genomic DNA. The technique can also detect footprinting or sequencing patterns introduced into genomic DNA by other methods. Purified genomic DNA, containing either damaged bases or strand breaks introduced by footprinting or sequencing reactions, is first cut with a convenient restriction enzyme to reduce its molecular weight. A highly radioactive single-stranded DNA primer that is complementary to a region of genomic DNA whose sequence or footprint one wishes to examine is then mixed with 50 micrograms of restriction enzyme-cut genomic DNA. The primer is approximately 100 bases long and contains 85 radioactive phosphates, each of specific activity 3000 Ci/mmol (1 Ci = 37 GBq). A simple and fast method for preparing such primers is described. Following brief heat denaturation at 100 degrees C, the solution of genomic DNA and primer is cooled to 74 degrees C and a second solution containing Taq polymerase (Thermus aquaticus DNA polymerase) and the four deoxynucleotide triphosphates is added to initiate primer extension of genomic DNA. Taq polymerase extends genomic hybridized primer until its polymerization reaction is terminated either by a damaged base or strand break in genomic DNA or by the addition of dideoxynucleotide triphosphates in the polymerization reaction. The concurrent primer hybridization-extension reaction is terminated after 5 hr and unhybridized primer is digested away by mung bean nuclease. Primer-extended genomic DNA is then denatured and electrophoresed on a polyacrylamide sequencing gel, and radioactive primer extension products are revealed by autoradiography

  12. The X-ray footprint of the circumnuclear disc

    Science.gov (United States)

    Mossoux, Enmanuelle; Eckart, Andreas

    2018-03-01

    We studied the central regions of the Galactic Centre to determine if the circumnuclear disc (CND) acts as an absorber or a barrier for the central X-rays diffuse emission. After reprocessing 4.6 Ms of Chandra observations, we were able to detect, for the first time, a depression in the X-ray luminosity of the diffuse emission whose size and location correspond to those of the CND. We extracted the X-ray spectra for various regions inside the CND footprint as well as for the region where the footprint is observed and for a region located outside the footprint. We simultaneously fitted these spectra as an optically thin plasma whose absorption by the interstellar medium (ISM) and by the local plasma were fitted independently using the Markov chain Monte Carlo method. The hydrogen column density of the ISM is 7.5 × 1022 cm-2. The X-ray diffuse emission inside the CND footprint is formed by a 2T plasma of 1 and 4 keV with slightly super-solar abundances except for the iron and carbon that are sub-solar. The plasma from the CND, in turn, is better described by a 1T model with abundances and local hydrogen column density that are very different from those of the innermost regions. The large iron abundance in this region confirms that the CND is dominated by the shock-heated ejecta of the Sgr A East supernova remnant. We deduced that the CND rather acts as a barrier for the Galactic Centre plasma and that the plasma located outside the CND may correspond to the collimated outflow possibly created by Sgr A* or the interaction between the wind of massive stars and the mini-spiral material.

  13. Pengaruh Paradigma Lingkungan dan Personal Value terhadap Carbon Footprint Mahasiswa

    OpenAIRE

    Malisi, Ali Sibro; Nadiroh, Nadiroh

    2017-01-01

    The objective of the research was aimed to finding the influence of environmental paradigm and personal value on environmental issues. Here, the effect of environmental paradigm and personal value on environmental using Carbon Footprint Analysis were evaluated on students at Universitas Negeri Jakarta. This research uses quantitative expost facto method with sample of 194 students. The results showed that there is influence of environmental paradigm and personal value to total carbon footprin...

  14. Carbon footprint of the cigarette industry - an analysis from India

    Directory of Open Access Journals (Sweden)

    Pranay Lal

    2018-03-01

    Given that manufacturing cigarette has a deep and significant environmental footprint makes for a strong case on environmental grounds to cease production of tobacco and production of tobacco products. To do this, tobacco control advocates need to reach out to environmental organisations, many of whom receive financial support from tobacco companies, which is an inherent conflict of interest. Environmental organisations are oblivious of this paradox.

  15. Photodissociative Cross-Linking of Non-covalent Peptide-Peptide Ion Complexes in the Gas Phase

    Science.gov (United States)

    Nguyen, Huong T. H.; Andrikopoulos, Prokopis C.; Rulíšek, Lubomír; Shaffer, Christopher J.; Tureček, František

    2018-05-01

    We report a gas-phase UV photodissociation study investigating non-covalent interactions between neutral hydrophobic pentapeptides and peptide ions incorporating a diazirine-tagged photoleucine residue. Phenylalanine (Phe) and proline (Pro) were chosen as the conformation-affecting residues that were incorporated into a small library of neutral pentapeptides. Gas-phase ion-molecule complexes of these peptides with photo-labeled pentapeptides were subjected to photodissociation. Selective photocleavage of the diazirine ring at 355 nm formed short-lived carbene intermediates that underwent cross-linking by insertion into H-X bonds of the target peptide. The cross-link positions were established from collision-induced dissociation tandem mass spectra (CID-MS3) providing sequence information on the covalent adducts. Effects of the amino acid residue (Pro or Phe) and its position in the target peptide sequence were evaluated. For proline-containing peptides, interactions resulting in covalent cross-links in these complexes became more prominent as proline was moved towards the C-terminus of the target peptide sequence. The photocross-linking yields of phenylalanine-containing peptides depended on the position of both phenylalanine and photoleucine. Density functional theory calculations were used to assign structures of low-energy conformers of the (GLPMG + GLL*LK + H)+ complex. Born-Oppenheimer molecular dynamics trajectory calculations were used to capture the thermal motion in the complexes within 100 ps and determine close contacts between the incipient carbene and the H-X bonds in the target peptide. This provided atomic-level resolution of potential cross-links that aided spectra interpretation and was in agreement with experimental data. [Figure not available: see fulltext.

  16. Electron tunneling in chemistry

    International Nuclear Information System (INIS)

    Zamaraev, K.I.; Khajrutdinov, R.F.; Zhdanov, V.P.; Molin, Yu.N.

    1985-01-01

    Results of experimental and theoretical investigations are outlined systematically on electron tunnelling in chemical reactions. Mechanism of electron transport to great distances is shown to be characteristic to chemical compounds of a wide range. The function of tunnel reactions is discussed for various fields of chemistry, including radiation chemistry, electrochemistry, chemistry of solids, chemistry of surface and catalysis

  17. Sustainability of the city and its ecological footprint

    Directory of Open Access Journals (Sweden)

    Petrić Jasna

    2004-01-01

    Full Text Available There are some agreed sustainability indicators, even some agreed target values regarding a sustainable city, but they still have to be underpinned by empirical evidence. The common starting point of definitions is generally the destructive impact of the city on its regional and global environment which can be observed in form of the depletion of natural resources and the pollution of soil, water and air. A sustainable city is therefore generally regarded to be the one that is compact and preserves land, has mixed use to increase access and reduce need to travel, is socially and economically balanced, uses clean and renewable energy and recycles all its waste. However, the sustainable city cannot exist as a self-sufficient unit, in ignorance of relationship with its hinterland. The ecological footprint which is the amount of land required to produce resources to sustain our quality of life is a yardstick for measuring the ecological bottom line of sustainability. With a sustainable city target to relieve pressure on the countryside, there is an increasing awareness of the importance of calculating city’s ecological footprint and see how it relates to the target global average. Although problem of reducing ecological footprints primarily concerns the wealthiest countries, it has to be fully acknowledged in the less economically developed part of the world, while recognising that cities themselves provide many potential solutions.

  18. Embedded Volttron specification - benchmarking small footprint compute device for Volttron

    Energy Technology Data Exchange (ETDEWEB)

    Sanyal, Jibonananda [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Fugate, David L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Woodworth, Ken [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Nutaro, James J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Kuruganti, Teja [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-08-17

    An embedded system is a small footprint computing unit that typically serves a specific purpose closely associated with measurements and control of hardware devices. These units are designed for reasonable durability and operations in a wide range of operating conditions. Some embedded systems support real-time operations and can demonstrate high levels of reliability. Many have failsafe mechanisms built to handle graceful shutdown of the device in exception conditions. The available memory, processing power, and network connectivity of these devices are limited due to the nature of their specific-purpose design and intended application. Industry practice is to carefully design the software for the available hardware capability to suit desired deployment needs. Volttron is an open source agent development and deployment platform designed to enable researchers to interact with devices and appliances without having to write drivers themselves. Hosting Volttron on small footprint embeddable devices enables its demonstration for embedded use. This report details the steps required and the experience in setting up and running Volttron applications on three small footprint devices: the Intel Next Unit of Computing (NUC), the Raspberry Pi 2, and the BeagleBone Black. In addition, the report also details preliminary investigation of the execution performance of Volttron on these devices.

  19. Carbon Footprint Analysis of Municipalities – Evidence from Greece

    Directory of Open Access Journals (Sweden)

    K. Angelakoglou

    2015-11-01

    Full Text Available The economical crisis that hit Greece after 2009, significantly affected its energy consumption profile due to the increased price of domestic heating oil and gasoline. The specific study aims at the quantification of the carbon dioxide emissions in municipal level due to energy and fuel consumption. Three different municipalities in North Greece (Kavala, Alexandroupolis and Drama were assessed with the application of three different carbon footprint estimation approaches in each one of them, including two life cycle assessment methods. Results ranged from 511,799 to 571,000, 435,250 to 489,000 and 355,207 to 398,000 tons CO2 and tons CO2-eq. for Kavala, Alexandroupolis and Drama respectively. The analysis per energy type indicated the electrical energy consumption as the key factor affecting the results due to the relatively high CO2 emission coefficient of the electricity produced in Greece. The analysis per sector indicated that a percentage of nearly 75% of the total carbon footprint is assigned to the building sector whereas the private and commercial transport is accountable for the rest. Municipal activities (buildings, facilities, lighting and fleet contributed to a small percentage to the total carbon footprint (approx. 3-8%.

  20. High resolution production water footprints of the United States

    Science.gov (United States)

    Marston, L.; Yufei, A.; Konar, M.; Mekonnen, M.; Hoekstra, A. Y.

    2017-12-01

    The United States is the largest producer and consumer of goods and services in the world. Rainfall, surface water supplies, and groundwater aquifers represent a fundamental input to this economic production. Despite the importance of water resources to economic activity, we do not have consistent information on water use for specific locations and economic sectors. A national, high-resolution database of water use by sector would provide insight into US utilization and dependence on water resources for economic production. To this end, we calculate the water footprint of over 500 food, energy, mining, services, and manufacturing industries and goods produced in the US. To do this, we employ a data intensive approach that integrates water footprint and input-output techniques into a novel methodological framework. This approach enables us to present the most detailed and comprehensive water footprint analysis of any country to date. This study broadly contributes to our understanding of water in the US economy, enables supply chain managers to assess direct and indirect water dependencies, and provides opportunities to reduce water use through benchmarking.

  1. Estimating Green Water Footprints in a Temperate Environment

    Directory of Open Access Journals (Sweden)

    Tim Hess

    2010-07-01

    Full Text Available The “green” water footprint (GWF of a product is often considered less important than the “blue” water footprint (BWF as “green” water generally has a low, or even negligible, opportunity cost. However, when considering food, fibre and tree products, is not only a useful indicator of the total appropriation of a natural resource, but from a methodological perspective, blue water footprints are frequently estimated as the residual after green water is subtracted from total crop water use. In most published studies, green water use (ETgreen has been estimated from the FAO CROPWAT model using the USDA method for effective rainfall. In this study, four methods for the estimation of the ETgreen of pasture were compared. Two were based on effective rainfall estimated from monthly rainfall and potential evapotranspiration, and two were based on a simulated water balance using long-term daily, or average monthly, weather data from 11 stations in England. The results show that the effective rainfall methods significantly underestimate the annual ETgreen in all cases, as they do not adequately account for the depletion of stored soil water during the summer. A simplified model, based on annual rainfall and reference evapotranspiration (ETo has been tested and used to map the average annual ETgreen of pasture in England.

  2. Carbon footprint of aerobic biological treatment of winery wastewater.

    Science.gov (United States)

    Rosso, D; Bolzonella, D

    2009-01-01

    The carbon associated with wastewater and its treatment accounts for approximately 6% of the global carbon balance. Within the wastewater treatment industry, winery wastewater has a minor contribution, although it can have a major impact on wine-producing regions. Typically, winery wastewater is treated by biological processes, such as the activated sludge process. Biomass produced during treatment is usually disposed of directly, i.e. without digestion or other anaerobic processes. We applied our previously published model for carbon-footprint calculation to the areas worldwide producing yearly more than 10(6) m(3) of wine (i.e., France, Italy, Spain, California, Argentina, Australia, China, and South Africa). Datasets on wine production from the Food and Agriculture Organisation were processed and wastewater flow rates calculated with assumptions based on our previous experience. Results show that the wine production, hence the calculated wastewater flow, is reported as fairly constant in the period 2005-2007. Nevertheless, treatment process efficiency and energy-conservation may play a significant role on the overall carbon-footprint. We performed a sensitivity analysis on the efficiency of the aeration process (alphaSOTE per unit depth, or alphaSOTE/Z) in the biological treatment operations and showed significant margin for improvement. Our results show that the carbon-footprint reduction via aeration efficiency improvement is in the range of 8.1 to 12.3%.

  3. Water Footprint and Virtual Water Trade of Brazil

    Directory of Open Access Journals (Sweden)

    Vicente de Paulo R. da Silva

    2016-11-01

    Full Text Available Freshwater scarcity has increased at an alarming rate worldwide; improved water management plays a vital role in increasing food production and security. This study aims to determine the water footprint of Brazil’s national food consumption, the virtual water flows associated with international trade in the main agricultural commodities, as well as water scarcity, water self-sufficiency and water dependency per Brazilian region. While previous country studies on water footprints and virtual water trade focused on virtual water importers or water-scarce countries, this is the first study to concentrate on a water-abundant virtual water-exporting country. Besides, it is the first study establishing international virtual water trade balances per state, which is relevant given the fact that water scarcity varies across states within the country, so the origin of virtual water exports matters. The results show that the average water footprint of Brazilian food consumption is 1619 m3/person/year. Beef contributes most (21% to this total. We find a net virtual water export of 54.8 billion m3/year, mainly to Europe, which imports 41% of the gross amount of the virtual water exported from Brazil. The northeast, the region with the highest water scarcity, has a net import of virtual water. The southeast, next in terms of water scarcity, shows large virtual water exports, mainly related to the export of sugar. The north, which has the most water, does not show a high virtual water export rate.

  4. Four Years of Chemical Measurements from the Deepwater Horizon Oil Spill Define the Deep Sea Sediment footprint and Subsequent Recovery

    Science.gov (United States)

    Boehm, P.

    2016-02-01

    Chemical data acquired during and after the DWHOS showed that several mechanisms were responsible for transport of oil from the water column to the sediments in the deep sea off the continental shelf. Three primary pathways were identified:Sorption onto and sinking of drilling mud particles during "Top Kill" response activity, highly scattered deposition of residuesfrom in situ burns, and deposition of oil combined with microbial organic matter from diffuse oil plumes ("marine snow"). Data collected during 2010, 2011 and 2014 were used to define the oil footprint and estimate time to recovery. More than 1200 stations were sampled. Of these, 27 stations were visited all three years, providing a time series from which recovery rates were calculated using the loss of total polycyclic aromatic hydrocarbons (TPAH) over time fit to first order kinetics. Results showed that the footprint of the oil was limited to the area around the wellhead and in patches to the southwest. Mostsamples had returned to background levels by 2015, with some exceptions close to the wellhead. Deposition to the northeast (DeSoto Canyon) was minor as evidenced by the absence of oil in sediments in that area. Samples with the longest recovery times were within 2 nautical miles of the wellhead, and often contained drilling mud, as shown by olefin signatures on the GC/FID chromatogram. Detailed chemistry data evaluation and chemical fingerprinting provided evidence that oil was being degraded in situ.

  5. Understanding the LCA and ISO water footprint: A response to Hoekstra (2016) “A critique on the water-scarcity weighted water footprint in LCA”

    Science.gov (United States)

    Water footprinting has emerged as an important approach to assess water use related effects from consumption of goods and services. Assessment methods are proposed by two different communities, the Water Footprint Network (WFN) and the Life Cycle Assessment (LCA) community. The p...

  6. Integrating ecological, carbon and water footprint into a "footprint family" of indicators: Definition and role in tracking human pressure on the planet

    NARCIS (Netherlands)

    Galli, A.; Wiedmann, T.O.; Ercin, Ertug; Knoblauch, D.; Ewing, B.R.; Giljum, S.

    2012-01-01

    In recent years, attempts have been made to develop an integrated Footprint approach for the assessment of the environmental impacts of production and consumption. In this paper, we provide for the first time a definition of the “Footprint Family” as a suite of indicators to track human pressure on

  7. Place oriented ecological footprint analysis. The case of Israel's grain supply

    International Nuclear Information System (INIS)

    Kissinger, Meidad; Gottlieb, Dan

    2010-01-01

    In today's world, any nation's ecological footprint is spread all over the globe. Still, most footprint studies are not yet sensitive to the specific locations on which the footprint falls and to the unique production characteristics of each supporting region. In recent years some studies have acknowledged the need to quantify the 'real land' footprints and particularly the share of the footprint embodied in trade. Our goal is to analyse the ecological footprint of grain-based consumption in the state of Israel during the last two decades. We present a detailed, place oriented calculation procedure of Israel's grain footprint on specific locations around the world. We document modes of production, major energy inputs in specific sources of supply, the energy required for shipping from each source, and the CO 2 emissions from those operations. Our research reveals that most of Israel's grain footprint falls on North America followed by the Black Sea region. It also shows that while the overall consumption of grain products has increased throughout the research period, the size of the footprint has been dropping in recent years as a consequence of changing sources of supply and grain composition. Finally, we discuss some of the implications of the method presented here for future footprint calculations and environmental resource management. (author)

  8. Heel–Ball index: An analysis of footprint dimensions for determination of sex

    Directory of Open Access Journals (Sweden)

    Tanuj Kanchan

    2014-06-01

    Full Text Available Determination of sex from the footprints recovered at crime scenes can help the investigation by narrowing down the pool of possible suspects. The present research studies the dimensions of the heel and the ball in footprints, and derives the Heel–Ball (HB index from these foot dimensions with the aim to find out if the foot dimensions and the HB index exhibit sexual dimorphisms. The study was carried out on 100 individuals (50 males, 50 females of Indian origin. Footprints were obtained from both feet of the study participants using standard techniques. Thus, a total of 200 footprints were obtained. The breadth of the footprint at ball (BBAL and the breadth of the footprint at heel (BHEL were measured on the footprints. The HB index was derived as (BHEL ÷ BBAL × 100. The footprint measurements at the ball and heel were significantly larger in males on both the sides. Likewise, the derived HB index was larger in males in both feet, but the sex differences were not statistically significant. The study concludes that though footprint dimensions can be used in the determination of sex, the HB index may not be utilized in sex determination from footprints.

  9. An Integrated Tool for Calculating and Reducing Institution Carbon and Nitrogen Footprints

    Science.gov (United States)

    Galloway, James N.; Castner, Elizabeth A.; Andrews, Jennifer; Leary, Neil; Aber, John D.

    2017-01-01

    Abstract The development of nitrogen footprint tools has allowed a range of entities to calculate and reduce their contribution to nitrogen pollution, but these tools represent just one aspect of environmental pollution. For example, institutions have been calculating their carbon footprints to track and manage their greenhouse gas emissions for over a decade. This article introduces an integrated tool that institutions can use to calculate, track, and manage their nitrogen and carbon footprints together. It presents the methodology for the combined tool, describes several metrics for comparing institution nitrogen and carbon footprint results, and discusses management strategies that reduce both the nitrogen and carbon footprints. The data requirements for the two tools overlap substantially, although integrating the two tools does necessitate the calculation of the carbon footprint of food. Comparison results for five institutions suggest that the institution nitrogen and carbon footprints correlate strongly, especially in the utilities and food sectors. Scenario analyses indicate benefits to both footprints from a range of utilities and food footprint reduction strategies. Integrating these two footprints into a single tool will account for a broader range of environmental impacts, reduce data entry and analysis, and promote integrated management of institutional sustainability. PMID:29350217

  10. Characteristics of the water footprint of rice production under different rainfall years in Jilin Province, China.

    Science.gov (United States)

    Li, Hongying; Qin, Lijie; He, Hongshi

    2018-06-01

    Rice is a special crop, and its production differs from that of other crops because it requires a thin layer of water coverage for a long period. The calculation of the water footprint of rice production should differ from that of other crops owing to the rice growing process. This study improved the calculation of blue and grey water footprints of rice production and analyzed the variations in the water footprints for rice production under different rainfall years in Jilin Province. In the drought year, the green water footprint was the lowest and the blue water footprint was the highest among the three years, while in the humid year, the green water footprint was the highest and the blue water footprint was not the lowest. The areas with higher water footprints were found in the east and west regions of Jilin Province, while the areas with lower water footprints were found in the middle east and middle regions of Jilin Province. Blue water was the primary water resource for rice production, although more precipitation provided the highest green water in the humid year; also, the spatial distributions of water footprints were not the same under different rainfall years. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  11. Tracking urban carbon footprints from production and consumption perspectives

    International Nuclear Information System (INIS)

    Lin, Jianyi; Hu, Yuanchao; Cui, Shenghui; Kang, Jiefeng; Ramaswami, Anu

    2015-01-01

    Cities are hotspots of socio-economic activities and greenhouse gas emissions. The aim of this study was to extend the research range of the urban carbon footprint (CF) to cover emissions embodied in products traded among regions and intra-city sectors. Using Xiamen City as a study case, the total urban-related emissions were evaluated, and the carbon flows among regions and intra-city sectors were tracked. Then five urban CF accountings were evaluated, including purely geographic accounting (PGA), community-wide infrastructure footprint (CIF), and consumption-based footprint (CBF) methods, as well as the newly defined production-based footprint (PBF) and purely production footprint (PPF). Research results show that the total urban-related emissions of Xiamen City in 2010 were 55.2 Mt CO 2 e/y, of which total carbon flow among regions or intra-city sectors accounted for 53.7 Mt CO 2 e/y. Within the total carbon flow, import and export respectively accounted for 59 and 65%, highlighting the importance of emissions embodied in trade. By regional trade balance, North America and Europe were the largest net carbon exported-to regions, and Mainland China and Taiwan the largest net carbon imported-from regions. Among intra-sector carbon flows, manufacturing was the largest emission-consuming sector of the total urban carbon flow, accounting for 77.4, and 98% of carbon export was through industrial products trade. By the PBF, PPF, CIF, PGA and CBF methods, the urban CFs were respectively 53.7 Mt CO 2 e/y, 44.8 Mt CO 2 e/y, 28.4 Mt CO 2 e/y, 23.7 Mt CO 2 e/y, and 19.0 Mt CO 2 e/y, so all of the other four CFs were higher than the CBF. All of these results indicate that urban carbon mitigation must consider the supply chain management of imported goods, the production efficiency within the city, the consumption patterns of urban consumers, and the responsibility of the ultimate consumers outside the city. (letter)

  12. Tracking urban carbon footprints from production and consumption perspectives

    Science.gov (United States)

    Lin, Jianyi; Hu, Yuanchao; Cui, Shenghui; Kang, Jiefeng; Ramaswami, Anu

    2015-05-01

    Cities are hotspots of socio-economic activities and greenhouse gas emissions. The aim of this study was to extend the research range of the urban carbon footprint (CF) to cover emissions embodied in products traded among regions and intra-city sectors. Using Xiamen City as a study case, the total urban-related emissions were evaluated, and the carbon flows among regions and intra-city sectors were tracked. Then five urban CF accountings were evaluated, including purely geographic accounting (PGA), community-wide infrastructure footprint (CIF), and consumption-based footprint (CBF) methods, as well as the newly defined production-based footprint (PBF) and purely production footprint (PPF). Research results show that the total urban-related emissions of Xiamen City in 2010 were 55.2 Mt CO2e/y, of which total carbon flow among regions or intra-city sectors accounted for 53.7 Mt CO2e/y. Within the total carbon flow, import and export respectively accounted for 59 and 65%, highlighting the importance of emissions embodied in trade. By regional trade balance, North America and Europe were the largest net carbon exported-to regions, and Mainland China and Taiwan the largest net carbon imported-from regions. Among intra-sector carbon flows, manufacturing was the largest emission-consuming sector of the total urban carbon flow, accounting for 77.4, and 98% of carbon export was through industrial products trade. By the PBF, PPF, CIF, PGA and CBF methods, the urban CFs were respectively 53.7 Mt CO2e/y, 44.8 Mt CO2e/y, 28.4 Mt CO2e/y, 23.7 Mt CO2e/y, and 19.0 Mt CO2e/y, so all of the other four CFs were higher than the CBF. All of these results indicate that urban carbon mitigation must consider the supply chain management of imported goods, the production efficiency within the city, the consumption patterns of urban consumers, and the responsibility of the ultimate consumers outside the city.

  13. Carbon footprint of dairy goat milk production in New Zealand.

    Science.gov (United States)

    Robertson, Kimberly; Symes, Wymond; Garnham, Malcolm

    2015-07-01

    The aim of this study was to assess the cradle-to-farm gate carbon footprint of indoor and outdoor dairy goat farming systems in New Zealand, identifying hotspots and discussing variability and methodology. Our study was based on the International Organization for Standardization standards for life cycle assessment, although only results for greenhouse gas emissions are presented. Two functional units were included: tonnes of CO2-equivalents (CO2e) per hectare (ha) and kilograms of CO2e per kilogram of fat- and protein-corrected milk (FPCM). The study covered 5 farms, 2 farming systems, and 3yr. Two methods for the calculation of enteric methane emissions were assessed. The Lassey method, as used in the New Zealand greenhouse gas inventory, provided a more robust estimate of emissions from enteric fermentation and was used in the final calculations. The alternative dry matter intake method was shown to overestimate emissions due to use of anecdotal assumptions around actual consumption of feed. Economic allocation was applied to milk and co-products. Scenario analysis was performed on the allocation method, nitrogen content of manure, manure management, and supplementary feed choice. The average carbon footprint for the indoor farms (n=3) was 11.05 t of CO2e/ha and 0.81kg of CO2e/kg of FPCM. For the outdoor farms (n=2), the average was 5.38 t of CO2e/ha and 1.03kg of CO2e/kg of FPCM. The average for all 5 farms was 8.78 t of CO2e/ha and 0.90kg of CO2e/kg of FPCM. The results showed relatively high variability due to differences in management practices between farms. The 5 farms covered 10% of the total dairy goat farms but may not be representative of an average farm. Methane from enteric fermentation was a major emission source. The use of supplementary feed was highly variable but an important contributor to the carbon footprint. Nitrous oxide can contribute up to 18% of emissions. Indoor goat farming systems produced milk with a significantly higher carbon

  14. Green chemistry: A tool in Pharmaceutical Chemistry

    OpenAIRE

    Smita Talaviya; Falguni Majumdar

    2012-01-01

    Green chemistry expresses an area of research developing from scientific discoveries about pollution awareness and it utilizes a set of principles that reduces or eliminates the use or generation of hazardous substances in all steps of particular synthesis or process. Chemists and medicinal scientists can greatly reduce the risk to human health and the environment by following all the valuable principles of green chemistry. The most simple and direct way to apply green chemistry in pharmaceut...

  15. Water Footprint Assessment in the Agro-industry: A Case Study of Soy Sauce Production

    Science.gov (United States)

    Firda, Alfiana Aulia; Purwanto

    2018-02-01

    In terms of global water scarcity, the water footprint is an indicator of the use of water resources that given knowledge about the environmental impact of consuming a product. The sustainable use of water resources nowadays bring challenges related to the production and consumption phase of water intensive related goods such as in the agro-industry. The objective of the study was to assessment the total water footprint from soy sauce production in Grobogan Regency. The total water footprint is equal to the sum of the supply chain water footprint and the operational water footprint. The assessment is based on the production chain diagram of soy sauce production which presenting the relevant process stages from the source to the final product. The result of this research is the total water footprint of soy sauce production is 1.986,35 L/kg with fraction of green water 78,43%, blue water 21,4% and gray water 0,17%.

  16. Nitrogen footprints: Regional realities and options to reduce nitrogen loss to the environment.

    Science.gov (United States)

    Shibata, Hideaki; Galloway, James N; Leach, Allison M; Cattaneo, Lia R; Cattell Noll, Laura; Erisman, Jan Willem; Gu, Baojing; Liang, Xia; Hayashi, Kentaro; Ma, Lin; Dalgaard, Tommy; Graversgaard, Morten; Chen, Deli; Nansai, Keisuke; Shindo, Junko; Matsubae, Kazuyo; Oita, Azusa; Su, Ming-Chien; Mishima, Shin-Ichiro; Bleeker, Albert

    2017-03-01

    Nitrogen (N) management presents a sustainability dilemma: N is strongly linked to energy and food production, but excess reactive N causes environmental pollution. The N footprint is an indicator that quantifies reactive N losses to the environment from consumption and production of food and the use of energy. The average per capita N footprint (calculated using the N-Calculator methodology) of ten countries varies from 15 to 47 kg N capita -1 year -1 . The major cause of the difference is the protein consumption rates and food production N losses. The food sector dominates all countries' N footprints. Global connections via trade significantly affect the N footprint in countries that rely on imported foods and feeds. The authors present N footprint reduction strategies (e.g., improve N use efficiency, increase N recycling, reduce food waste, shift dietary choices) and identify knowledge gaps (e.g., the N footprint from nonfood goods and soil N process).

  17. From hot atom chemistry to epithermal chemistry

    International Nuclear Information System (INIS)

    Roessler, K.

    2004-01-01

    The rise and fall of hot atom chemistry (HAC) over the years from 1934 to 2004 is reviewed. Several applications are discussed, in particular to astrophysics and the interaction of energetic ions and atoms in space. Epithermal chemistry (ETC) is proposed to substitute the old name, since it better fits the energy range as well as the non-thermal and non-equilibrium character of the reactions. ETC also avoids the strong connexion of HAC to nuclear chemistry and stands for the opening of the field to physical chemistry and astrophysics. (orig.)

  18. Water Footprint Assessment in the Agro-industry: A Case Study of Soy Sauce Production

    OpenAIRE

    Aulia Firda Alfiana; Purwanto

    2018-01-01

    In terms of global water scarcity, the water footprint is an indicator of the use of water resources that given knowledge about the environmental impact of consuming a product. The sustainable use of water resources nowadays bring challenges related to the production and consumption phase of water intensive related goods such as in the agro-industry. The objective of the study was to assessment the total water footprint from soy sauce production in Grobogan Regency. The total water footprint ...

  19. Dinosaur footprints in the Upper Turonian-Coniacian limestone in the Krnica Bay (NE Istria, Croatia

    Directory of Open Access Journals (Sweden)

    Alenka Mauko

    2003-06-01

    Full Text Available Three isolated footprints and one trackway that can be attributed to bipedal dinosaur, from a limestone bed in vicinity of Požara promontory, Krnica Bay, are described. According to the stratigraphic position the footprints are late Turonian to Coniacian in age.This is the first record of dinosaur remains in the Turonian-Coniacian and the youngest footprint site on the Adriatic-Dinaric Carbonate Platform described thus far.

  20. The latest general chemistry

    International Nuclear Information System (INIS)

    Ryu, Geun Bae; Choi, Se Yeong; Kim, Chin Yeong; Yoon, Gil Jung; Lee, Eun Seok; Seo, Moon Gyu

    1995-02-01

    This book deals with the latest general chemistry, which is comprised of twenty-three chapters, the contents of this book are introduction, theory of atoms and molecule, chemical formula and a chemical reaction formula, structure of atoms, nature of atoms and the periodic table, structure of molecule and spectrum, gas, solution, solid, chemical combination, chemical reaction speed, chemical equilibrium, thermal chemistry, oxidation-reduction, electrochemistry, acid-base, complex, aquatic chemistry, air chemistry, nuclear chemistry, metal and nonmetal, organic chemistry and biochemistry. It has exercise in the end of each chapter.

  1. Constitutional dynamic chemistry: bridge from supramolecular chemistry to adaptive chemistry.

    Science.gov (United States)

    Lehn, Jean-Marie

    2012-01-01

    Supramolecular chemistry aims at implementing highly complex chemical systems from molecular components held together by non-covalent intermolecular forces and effecting molecular recognition, catalysis and transport processes. A further step consists in the investigation of chemical systems undergoing self-organization, i.e. systems capable of spontaneously generating well-defined functional supramolecular architectures by self-assembly from their components, thus behaving as programmed chemical systems. Supramolecular chemistry is intrinsically a dynamic chemistry in view of the lability of the interactions connecting the molecular components of a supramolecular entity and the resulting ability of supramolecular species to exchange their constituents. The same holds for molecular chemistry when the molecular entity contains covalent bonds that may form and break reversibility, so as to allow a continuous change in constitution by reorganization and exchange of building blocks. These features define a Constitutional Dynamic Chemistry (CDC) on both the molecular and supramolecular levels.CDC introduces a paradigm shift with respect to constitutionally static chemistry. The latter relies on design for the generation of a target entity, whereas CDC takes advantage of dynamic diversity to allow variation and selection. The implementation of selection in chemistry introduces a fundamental change in outlook. Whereas self-organization by design strives to achieve full control over the output molecular or supramolecular entity by explicit programming, self-organization with selection operates on dynamic constitutional diversity in response to either internal or external factors to achieve adaptation.The merging of the features: -information and programmability, -dynamics and reversibility, -constitution and structural diversity, points to the emergence of adaptive and evolutive chemistry, towards a chemistry of complex matter.

  2. Income-carbon footprint relationships for urban and rural households of Iskandar Malaysia

    Science.gov (United States)

    Majid, M. R.; Moeinzadeh, S. N.; Tifwa, H. Y.

    2014-02-01

    Iskandar Malaysia has a vision to achieve sustainable development and a low carbon society status by decreasing the amount of CO2 emission as much as 60% by 2025. As the case is in other parts of the world, households are suspected to be a major source of carbon emission in Iskandar Malaysia. At the global level, 72% of greenhouse gas emission is a consequence of household activities, which is influenced by lifestyle. Income is the most important indicator of lifestyle and consequently may influence the amount of households' carbon footprint. The main objective of this paper is to illustrate the carbon-income relationships in Iskandar Malaysia's urban and rural areas. Data were gathered through a questionnaire survey of 420 households. The households were classified into six categories based on their residential area status. Both direct and indirect carbon footprints of respondents were calculated using a carbon footprint model. Direct carbon footprint includes domestic energy use, personal travel, flight and public transportation while indirect carbon footprint is the total secondary carbon emission measurement such as housing operations, transportation operations, food, clothes, education, cultural and recreational services. Analysis of the results shows a wide range of carbon footprint values and a significance correlation between income and carbon footprint. The carbon footprints vary in urban and rural areas, and also across different urban areas. These identified carbon footprint values can help the authority target its carbon reduction programs.

  3. Ecotourism versus Mass Tourism. A Comparison of Environmental Impacts Based on Ecological Footprint Analysis

    Directory of Open Access Journals (Sweden)

    Jérôme Ballet

    2012-01-01

    Full Text Available Academic and policy interest in ecological footprint analysis has grown rapidly in recent years. To date, however, the application of ecological footprint analysis to tourism has been limited. This article aims to discuss the potential of ecological footprint analysis to assess sustainability in tourism. It is about a comparison of the global environmental impacts of different forms of tourism in southern countries where tourism is a major source of foreign exchange earnings. It illustrates how an ecotourism destination has a larger ecological footprint than a “mass” tourism destination.

  4. Income-carbon footprint relationships for urban and rural households of Iskandar Malaysia

    International Nuclear Information System (INIS)

    Majid, M R; Moeinzadeh, S N; Tifwa, H Y

    2014-01-01

    Iskandar Malaysia has a vision to achieve sustainable development and a low carbon society status by decreasing the amount of CO 2 emission as much as 60% by 2025. As the case is in other parts of the world, households are suspected to be a major source of carbon emission in Iskandar Malaysia. At the global level, 72% of greenhouse gas emission is a consequence of household activities, which is influenced by lifestyle. Income is the most important indicator of lifestyle and consequently may influence the amount of households' carbon footprint. The main objective of this paper is to illustrate the carbon-income relationships in Iskandar Malaysia's urban and rural areas. Data were gathered through a questionnaire survey of 420 households. The households were classified into six categories based on their residential area status. Both direct and indirect carbon footprints of respondents were calculated using a carbon footprint model. Direct carbon footprint includes domestic energy use, personal travel, flight and public transportation while indirect carbon footprint is the total secondary carbon emission measurement such as housing operations, transportation operations, food, clothes, education, cultural and recreational services. Analysis of the results shows a wide range of carbon footprint values and a significance correlation between income and carbon footprint. The carbon footprints vary in urban and rural areas, and also across different urban areas. These identified carbon footprint values can help the authority target its carbon reduction programs

  5. The carbon footprint of French people's consumption: evolution from 1990 to 2007

    International Nuclear Information System (INIS)

    Pasquier, Jean-Louis; Moreau, Sylvain; Bottin, Anne; Boitard, Corinne

    2012-03-01

    The carbon footprint calculated by the statistical service of the French ministry in charge of sustainable development represents the amount of greenhouse gases emitted in order to satisfy French consumption, including emissions connected to imports. In 2007, the carbon footprint per capita in France amounted to 12 tons of CO 2 -equivalent per year, compared to 8 tons per person emitted from the French metropolitan territory. From 1990 to 2007, the carbon footprint per capita increased by 5%, whereas the average per capita emissions on the territory decreased by 15%. During this period, emissions connected to imports increased by 64%, reaching almost 50% of the French carbon footprint in 2007. (author)

  6. Estimation of foot pressure from human footprint depths using 3D scanner

    Science.gov (United States)

    Wibowo, Dwi Basuki; Haryadi, Gunawan Dwi; Priambodo, Agus

    2016-03-01

    The analysis of normal and pathological variation in human foot morphology is central to several biomedical disciplines, including orthopedics, orthotic design, sports sciences, and physical anthropology, and it is also important for efficient footwear design. A classic and frequently used approach to study foot morphology is analysis of the footprint shape and footprint depth. Footprints are relatively easy to produce and to measure, and they can be preserved naturally in different soils. In this study, we need to correlate footprint depth with corresponding foot pressure of individual using 3D scanner. Several approaches are used for modeling and estimating footprint depths and foot pressures. The deepest footprint point is calculated from z max coordinate-z min coordinate and the average of foot pressure is calculated from GRF divided to foot area contact and identical with the average of footprint depth. Evaluation of footprint depth was found from importing 3D scanner file (dxf) in AutoCAD, the z-coordinates than sorted from the highest to the lowest value using Microsoft Excel to make footprinting depth in difference color. This research is only qualitatif study because doesn't use foot pressure device as comparator, and resulting the maximum pressure on calceneus is 3.02 N/cm2, lateral arch is 3.66 N/cm2, and metatarsal and hallux is 3.68 N/cm2.

  7. Photodissociation of hydrogen iodide on the surface of large argon clusters: The orientation of the librational wave function and the scattering from the cluster cage

    International Nuclear Information System (INIS)

    Slavicek, Petr; Jungwirth, Pavel; Lewerenz, Marius; Nahler, N. Hendrik; Farnik, Michal; Buck, Udo

    2004-01-01

    A set of photodissociation experiments and simulations of hydrogen iodide (HI) on Ar n clusters, with an average size =139, has been carried out for different laser polarizations. The doped clusters are prepared by a pick-up process. The HI molecule is then photodissociated by a UV laser pulse and the outgoing H fragment is ionized by resonance enhanced multiphoton ionization in a (2+1) excitation scheme within the same laser pulse at the wavelength of 243 nm. The measured time-of-flight spectra are transformed into hydrogen kinetic energy distributions. They exhibit a strong fraction of caged H atoms at zero-kinetic energy and peaks at the unperturbed cage exit for both spin-orbit channels nearly independent of the polarization. At this dissociation wavelength, the bare HI molecule exhibits a strict state separation, with a parallel transition to the spin-orbit excited state and perpendicular transitions to the ground state. The experimental results have been reproduced using molecular simulation techniques. Classical molecular dynamics was used to estimate the HI dopant distribution after the pick-up procedure. Subsequently, quasi-classical molecular dynamics (Wigner trajectories approach) has been applied for the photodissociation dynamics. The following main results have been obtained: (i) The HI dopant lands on the surface of the argon cluster during the pick-up process, (ii) zero-point energy plays a dominant role for the hydrogen orientation in the ground state of HI-Ar n surface clusters, qualitatively changing the result of the photodissociation experiment upon increasing the number of argon atoms, and, finally, (iii) the scattering of hydrogen atoms from the cage which originate from different dissociation states seriously affects the experimentally measured kinetic energy distributions

  8. The effects of nitric oxide cooling and the photodissociation of molecular oxygen on the thermosphere/ionosphere system over the Argentine Islands

    Directory of Open Access Journals (Sweden)

    G. D. Wells

    1997-03-01

    Full Text Available In the past the global, fully coupled, time-dependent mathematical model of the Earth's thermosphere/ionosphere/plasmasphere (CTIP has been unable to reproduce accurately observed values of the maximum plasma frequency, foF2, at extreme geophysical locations such as the Argentine Islands during the summer solstice where the ionosphere remains in sunlight throughout the day. This is probably because the seasonal dependence of thermospheric cooling by 5.3 µm nitric oxide has been neglected and the photodissociation of O2 and heating rate calculations have been over-simplified. Now we have included an up-to-date calculation of the solar EUV and UV thermospheric heating rate, coupled with a new calculation of a diurnally varying O2 photodissociation rate, in the model. Seasonally dependent 5.3 µm nitric oxide cooling is also included. With these important improvements, it is found that model values of foF2 are in substantially better agreement with observation. The height of the F2-peak is reduced throughout the day, but remains within acceptable limits of values derived from observation, except at around 0600 h LT. We also carry out two studies of the sensitivity of the upper atmosphere to changes in the magnitude of nitric oxide cooling and photodissociation rates. We find that hmF2 increases with increased heating, whilst foF2 falls. The converse is true for an increase in the cooling rate. Similarly increasing the photodissociation rate increases both hmF2 and foF2. These changes are explained in terms of changes in the neutral temperature, composition and neutral wind.

  9. Blue and grey water footprint of textile industry in China.

    Science.gov (United States)

    Wang, Laili; Ding, Xuemei; Wu, Xiongying

    2013-01-01

    Water footprint (WF) is a newly developed idea that indicates impacts of freshwater appropriation and wastewater discharge. The textile industry is one of the oldest, longest and most complicated industrial chains in the world's manufacturing industries. However, the textile industry is also water intensive. In this paper, we applied a bottom-up approach to estimate the direct blue water footprint (WFdir,blue) and direct grey water footprint (WFdir,grey) of China's textile industry at sector level based on WF methodology. The results showed that WFdir,blue of China's textile industry had an increasing trend from 2001 to 2010. The annual WFdir,blue surpassed 0.92 Gm(3)/yr (giga cubic meter a year) since 2004 and rose to peak value of 1.09 Gm(3)/yr in 2007. The original and residuary WFdir,grey (both were calculated based on the concentration of chemical oxygen demand (CODCr)) of China's textile industry had a similar variation trend with that of WFdir,blue. Among the three sub-sectors of China's textile industry, the manufacture of textiles sector's annual WFdir,blue and WFdir,grey were much larger than those of the manufacture of textile wearing apparel, footware and caps sector and the manufacture of chemical fibers sector. The intensities of WFdir,blue and WF(res)dir,grey of China's textile industry were year by year decreasing through the efforts of issuing restriction policies on freshwater use and wastewater generation and discharge, and popularization of water saving and wastewater treatment technologies.

  10. Assessing the Social and Environmental Costs of Institution Nitrogen Footprints.

    Science.gov (United States)

    Compton, Jana E; Leach, Allison M; Castner, Elizabeth A; Galloway, James N

    2017-04-01

    This article estimates the damage costs associated with the institutional nitrogen (N) footprint and explores how this information could be used to create more sustainable institutions. Potential damages associated with the release of nitrogen oxides (NOx), ammonia (NH 3 ), and nitrous oxide (N 2 O) to air and release of nitrogen to water were estimated using existing values and a cost per unit of nitrogen approach. These damage cost values were then applied to two universities. Annual potential damage costs to human health, agriculture, and natural ecosystems associated with the N footprint of institutions were $11.0 million (2014) at the University of Virginia (UVA) and $3.04 million at the University of New Hampshire (UNH). Costs associated with the release of nitrogen oxides to human health, in particular the use of coal-derived energy, were the largest component of damage at UVA. At UNH the energy N footprint is much lower because of a landfill cogeneration source, and thus the majority of damages were associated with food production. Annual damages associated with release of nitrogen from food production were very similar at the two universities ($1.80 million vs. $1.66 million at UVA and UNH, respectively). These damages also have implications for the extent and scale at which the damages are felt. For example, impacts to human health from energy and transportation are generally larger near the power plants and roads, while impacts from food production can be distant from the campus. Making this information available to institutions and communities can improve their understanding of the damages associated with the different nitrogen forms and sources, and inform decisions about nitrogen reduction strategies.

  11. The carbon footprint of behavioural support services for smoking cessation.

    Science.gov (United States)

    Smith, Anna Jo Bodurtha; Tennison, Imogen; Roberts, Ian; Cairns, John; Free, Caroline

    2013-09-01

    To estimate the carbon footprint of behavioural support services for smoking cessation: text message support, telephone counselling, group counselling and individual counselling. Carbon footprint analysis. Publicly available data on National Health Service Stop Smoking Services and per unit carbon emissions; published effectiveness data from the txt2stop trial and systematic reviews of smoking cessation services. Carbon dioxide equivalents (CO2e) per 1000 smokers, per lifetime quitter, and per quality-adjusted life year gained, and cost-effectiveness, including social cost of carbon, of smoking cessation services. Emissions per 1000 participants were 8143 kg CO2e for text message support, 8619 kg CO2e for telephone counselling, 16 114 kg CO2e for group counselling and 16 372 kg CO2e for individual counselling. Emissions per intervention lifetime quitter were 636 (95% CI 455 to 958) kg CO2e for text message support, 1051 (95% CI 560 to 2873) kg CO2e for telephone counselling, 1143 (95% CI 695 to 2270) kg CO2e for group counselling and 2823 (95% CI 1688 to 6549) kg CO2e for individual counselling. Text message, telephone and group counselling remained cost-effective when cost-effectiveness analysis was revised to include the environmental and economic cost of damage from carbon emissions. All smoking cessation services had low emissions compared to the health gains produced. Text message support had the lowest emissions of the services evaluated. Smoking cessation services have small carbon footprints and were cost-effective after accounting for the societal costs of greenhouse gas emissions.

  12. A molecular beam study of the one, two, and three photon photodissociation mechanism of the group VIB (Cr,Mo,W) hexacarbonyls at 248 nm

    International Nuclear Information System (INIS)

    Venkataraman, B.; Hou, H.; Zhang, Z.; Chen, S.; Bandukwalla, G.; Vernon, M.

    1990-01-01

    Photodissociation of the group VIB (Cr,Mo,W) hexacarbonyls has been studied at 248 nm using molecular beam photofragment spectroscopy. One, two and three photon processes have been observed. Analysis of the product velocity distributions shows that the photodissociation mechanism consists of sequential CO eliminations with the nth photon channel best described as the single photon photodissociation of the stable products of the n-1st photon channel. The product translational energy distribution for the first CO elimination step is quantitatively similar for all three hexacarbonyls and characteristic of a repulsive translational energy release. The product translational energy distributions of all subsequent CO elimination steps are accurately described by a simple, microcanonical model. Qualitative molecular orbital considerations suggest that the large product translational energy observed in the first CO elimination step results from a repulsive σ interaction between the closed shell CO ligand and an excited molecular orbital which has a significant admixture of metal (n+1)p z , (n+1)s and nd z 2 orbitals. This repulsive interaction is absent in the remaining CO elimination steps because there are vacancies in the coordination shell along the z axis

  13. 'Electron compression' of beam-beam footprint in the Tevatron

    International Nuclear Information System (INIS)

    Shiltsev, V.; Finley, D.A.

    1997-08-01

    The beam-beam interaction in the Tevatron collider sets some limits on bunch intensity and luminosity. These limits are caused by a tune spread in each bunch which is mostly due to head-on collisions, but there is also a bunch-to-bunch tune spread due to parasitic collisions in multibunch operation. We describe a counter-traveling electron beam which can be used to eliminate these effects, and present general considerations and physics limitations of such a device which provides 'electron compression' of the beam-beam footprint in the Tevatron

  14. Carbon footprints and legitimation strategies: Symbolism or action?

    Energy Technology Data Exchange (ETDEWEB)

    Hrasky, S. [Univ. of Tasmania (Australia)

    2009-07-01

    The term 'carbon footprint' is now firmly entrenched in the common vernacular where it tends to function ideographically, representing a range of concerns about environmental impacts and degradation. Political and consumer concern about the related issues of carbon emissions, climate change and global warming has been heightened by a number of factors. It is often claimed that, along with the US, Australia has one of the heaviest carbon footprints. However, according to KPMG's (2008) survey results only 32 per cent of the Australian companies included in its survey report specifically on their carbon footprints. Nonetheless, KPMG (2007) reports that around 85 per cent of the 500 largest listed Australian companies do report on the related issues of climate change and greenhouse gas emissions. Motivations for making such disclosures can vary widely but legitimacy theory has been used extensively to explain environmental disclosure decisions in the context of maintaining an implicit social contract between the company and its stakeholders. While, prima facie, increased levels of voluntary disclosures may be a constructive outcome there is the associated risk that, in pursuit of legitimation, such disclosure can actually 'thicken' the corporate veil. This can occur because organizational action to maintain the social contact can be both symbolic and behavioral. That is, the disclosure response might be calculated to create a positive impression of the firm's activities with no associated change in operations (symbolism) or it might convey a message about how operational changes have been effected that are more consistent with societal expectations. This study examines the disclosure strategies of large Australian companies in light of the heightened societal awareness and concern about issues related to carbon footprints. This first aim is to determine whether, consistent with a general need for legitimation, companies are addressing

  15. Water Use and Quality Footprints of Biofuel Crops in Florida

    Science.gov (United States)

    Shukla, S.; Hendricks, G.; Helsel, Z.; Knowles, J.

    2013-12-01

    The use of biofuel crops for future energy needs will require considerable amounts of water inputs. Favorable growing conditions for large scale biofuel production exist in the sub-tropical environment of South Florida. However, large-scale land use change associated with biofuel crops is likely to affect the quantity and quality of water within the region. South Florida's surface and ground water resources are already stressed by current allocations. Limited data exists to allocate water for growing the energy crops as well as evaluate the accompanying hydrologic and water quality impacts of large-scale land use changes. A three-year study was conducted to evaluate the water supply and quality impacts of three energy crops: sugarcane, switchgrass, and sweet sorghum (with a winter crop). Six lysimeters were used to collect the data needed to quantify crop evapotranspiration (ETc), and nitrogen (N) and phosphorus (P) levels in groundwater and discharge (drainage and runoff). Each lysimeter (4.85 x 3.65 x 1.35 m) was equipped to measure water input, output, and storage. The irrigation, runoff, and drainage volumes were measured using flow meters. Groundwater samples were collected bi-weekly and drainage/runoff sampling was event based; samples were analyzed for nitrogen (N) and phosphorous (P) species. Data collected over the three years revealed that the average annual ETc was highest for sugarcane (1464 mm) followed by switchgrass and sweet sorghum. Sweet sorghum had the highest total N (TN) concentration (7.6 mg/L) in groundwater and TN load (36 kg/ha) in discharge. However, sweet sorghum had the lowest total P (TP) concentration (1.2 mg/L) in groundwater and TP load (9 kg/ha) in discharge. Water use footprint for ethanol (liter of water used per liter of ethanol produced) was lowest for sugarcane and highest for switchgrass. Switchgrass had the highest P-load footprint for ethanol. No differences were observed for the TN load footprint for ethanol. This is the

  16. Estimating Biofuel Feedstock Water Footprints Using System Dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Inman, Daniel; Warner, Ethan; Stright, Dana; Macknick, Jordan; Peck, Corey

    2016-07-01

    Increased biofuel production has prompted concerns about the environmental tradeoffs of biofuels compared to petroleum-based fuels. Biofuel production in general, and feedstock production in particular, is under increased scrutiny. Water footprinting (measuring direct and indirect water use) has been proposed as one measure to evaluate water use in the context of concerns about depleting rural water supplies through activities such as irrigation for large-scale agriculture. Water footprinting literature has often been limited in one or more key aspects: complete assessment across multiple water stocks (e.g., vadose zone, surface, and ground water stocks), geographical resolution of data, consistent representation of many feedstocks, and flexibility to perform scenario analysis. We developed a model called BioSpatial H2O using a system dynamics modeling and database framework. BioSpatial H2O could be used to consistently evaluate the complete water footprints of multiple biomass feedstocks at high geospatial resolutions. BioSpatial H2O has the flexibility to perform simultaneous scenario analysis of current and potential future crops under alternative yield and climate conditions. In this proof-of-concept paper, we modeled corn grain (Zea mays L.) and soybeans (Glycine max) under current conditions as illustrative results. BioSpatial H2O links to a unique database that houses annual spatially explicit climate, soil, and plant physiological data. Parameters from the database are used as inputs to our system dynamics model for estimating annual crop water requirements using daily time steps. Based on our review of the literature, estimated green water footprints are comparable to other modeled results, suggesting that BioSpatial H2O is computationally sound for future scenario analysis. Our modeling framework builds on previous water use analyses to provide a platform for scenario-based assessment. BioSpatial H2O's system dynamics is a flexible and user

  17. Improving odour assessment in LCA—the odour footprint

    DEFF Research Database (Denmark)

    Peters, Gregory M.; Murphy, Kathleen R.; Adamsen, Anders Peter S.

    2014-01-01

    in the life cycle assessment (LCA) community. This article aims to redress this. Results and discussion: We produced a list of 33 linear characterisation factors based on hydrogen sulphide equivalents, analogous to the linear carbon dioxide equivalency factors in use in carbon footprinting...... assessment in LCA. Unlike it, the method presented here considers the persistence of odourants. Over time, we hope to increase the number of characterised odourants, enabling analysts to perform simple site-generic LCA on systems with odourant emissions. Methods: Firstly, a framework for the assessment...

  18. The Energetic Demands and Planetary Footprint of Alternative Human Diets

    Science.gov (United States)

    Eshel, G.; Martin, P. A.

    2005-12-01

    Agriculture is one of the major vehicles of human alteration of the planetary environment. Yet different diets vary vastly in terms of both their energetic demands and overall planetary footprint. We present a quantitative argument that demonstrates that plant-based diets exert vastly smaller planetary environmental cost than animal-based ones. We demonstrate that under a reasonable and readily defensible set of assumptions, a plant-based diet differs from the average American diet by as much energy as the difference between driving a compact and efficient sedan and a Sport Utility Vehicle.

  19. Ecological footprint accounting for energy and resource in China

    International Nuclear Information System (INIS)

    Chen, B.; Chen, G.Q.; Yang, Z.F.; Jiang, M.M.

    2007-01-01

    Resource consumption of the Chinese society from 1981 to 2001 is represented by ecological footprint (EF) as an aggregate indicator. The debate, advances and implications of EF are investigated in detail. EF intensity is also provided to depict the resource consumption level corresponding to unit economic output. The results show that the EF per capita always exceeded the biocapacity and the EF intensity increased steadily over the study period. In addition, sectoral analysis for each EF component is also conducted. The appropriation in the global ecological sense of Chinese society with the second largest energy consumption in the world is therefore quantified and evaluated

  20. Using extant taxa to inform studies of fossil footprints

    Science.gov (United States)

    Falkingham, Peter; Gatesy, Stephen

    2016-04-01

    Attempting to use the fossilized footprints of extinct animals to study their palaeobiology and palaeoecology is notoriously difficult. The inconvenient extinction of the trackmaker makes direct correlation between footprints and foot far from straightforward. However, footprints are the only direct evidence of vertebrate motion recorded in the fossil record, and are potentially a source of data on palaeobiology that cannot be obtained from osteological remains alone. Our interests lie in recovering information about the movements of dinosaurs from their tracks. In particular, the Hitchcock collection of early Jurassic tracks held at the Beneski Museum of Natural History, Amherst, provide a rare look into the 3D form of tracks at and below the surface the animal walked on. Breaking naturally along laminations into 'track books', the specimens present sediment deformation at multiple levels, and in doing so record more of the foot's motion than a single surface might. In order to utilize this rich information source to study the now extinct trackmakers, the process of track formation must be understood at a fundamental level; the interaction of the moving foot and compliant substrate. We used bi-planar X-ray techniques (X-ray Reconstruction of Moving Morphology) to record the limb and foot motions of a Guineafowl traversing both granular and cohesive substrates. This data was supplemented with photogrammetric records of the resultant track surfaces, as well as the motion of metal beads within the sediment, to provide a full experimental dataset of foot and footprint formation. The physical experimental data was used to generate computer simulations of the process using high performance computing and the Discrete Element Method. The resultant simulations showed excellent congruence with reality, and enabled visualization within the sediment volume, and throughout the track-forming process. This physical and virtual experimental set-up has provided major insight into

  1. Advanced Chemistry Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — Description/History: Chemistry laboratoryThe Advanced Chemistry Laboratory (ACL) is a unique facility designed for working with the most super toxic compounds known...

  2. Electrostatics in Chemistry

    Indian Academy of Sciences (India)

    fundamental concepts of electrostatics as applied to atoms and molecules. The electric ... chemistry, the chemistry of the covalent bond, deals with the structures ..... the position of an asteroid named Ceres ... World Scientific. Singapore, 1992.

  3. The green, blue and grey water footprint of crops and derived crop products

    Science.gov (United States)

    Mekonnen, M. M.; Hoekstra, A. Y.

    2011-05-01

    This study quantifies the green, blue and grey water footprint of global crop production in a spatially-explicit way for the period 1996-2005. The assessment improves upon earlier research by taking a high-resolution approach, estimating the water footprint of 126 crops at a 5 by 5 arc minute grid. We have used a grid-based dynamic water balance model to calculate crop water use over time, with a time step of one day. The model takes into account the daily soil water balance and climatic conditions for each grid cell. In addition, the water pollution associated with the use of nitrogen fertilizer in crop production is estimated for each grid cell. The crop evapotranspiration of additional 20 minor crops is calculated with the CROPWAT model. In addition, we have calculated the water footprint of more than two hundred derived crop products, including various flours, beverages, fibres and biofuels. We have used the water footprint assessment framework as in the guideline of the Water Footprint Network. Considering the water footprints of primary crops, we see that the global average water footprint per ton of crop increases from sugar crops (roughly 200 m3 ton-1), vegetables (300 m3 ton-1), roots and tubers (400 m3 ton-1), fruits (1000 m3 ton-1), cereals (1600 m3 ton-1), oil crops (2400 m3 ton-1) to pulses (4000 m3 ton-1). The water footprint varies, however, across different crops per crop category and per production region as well. Besides, if one considers the water footprint per kcal, the picture changes as well. When considered per ton of product, commodities with relatively large water footprints are: coffee, tea, cocoa, tobacco, spices, nuts, rubber and fibres. The analysis of water footprints of different biofuels shows that bio-ethanol has a lower water footprint (in m3 GJ-1) than biodiesel, which supports earlier analyses. The crop used matters significantly as well: the global average water footprint of bio-ethanol based on sugar beet amounts to 51 m3 GJ-1

  4. Preparative radiation chemistry

    International Nuclear Information System (INIS)

    Drawe, H.

    1978-01-01

    Preparative synthesis of compounds with the aid of radiation chemistry is increasingly used in laboratories as well as on a technical scale. A large number of new compounds has been produced with the methods of radiation chemistry. With the increasing number of available radiation sources, also the number of synthesis metods in radiation chemistry has increased. This paper can only briefly mention the many possible ways of synthesis in radiation chemistry. (orig./HK) [de

  5. USSR Report Chemistry

    National Research Council Canada - National Science Library

    1986-01-01

    THIS REPORT CONTAINS FOREIGN MEDIA INFORMATION FROM THE USSR CONCERNING Adsorption, Alkaloids, ANALYTICAL CHEMISTRY, CATALYSIS, ELECTROCHEMISTRY, Fertilizers, INORGANIC COMPOUNDS, ORGANOPHOSPHOROUS...

  6. Frontiers in Gold Chemistry

    OpenAIRE

    Ahmed A. Mohamed

    2015-01-01

    Basic chemistry of gold tells us that it can bond to sulfur, phosphorous, nitrogen, and oxygen donor ligands. The Frontiers in Gold Chemistry Special Issue covers gold complexes bonded to the different donors and their fascinating applications. This issue covers both basic chemistry studies of gold complexes and their contemporary applications in medicine, materials chemistry, and optical sensors. There is a strong belief that aurophilicity plays a major role in the unending applications of g...

  7. Organic chemistry experiment

    International Nuclear Information System (INIS)

    Mun, Seok Sik

    2005-02-01

    This book deals with organic chemistry experiments, it is divided five chapters, which have introduction, the way to write the experiment report and safety in the laboratory, basic experiment technic like recrystallization and extraction, a lot of organic chemistry experiments such as fischer esterification, ester hydrolysis, electrophilic aromatic substitution, aldol reaction, benzoin condensation, wittig reaction grignard reaction, epoxidation reaction and selective reduction. The last chapter introduces chemistry site on the internet and way to find out reference on chemistry.

  8. Communication: On the competition between adiabatic and nonadiabatic dynamics in vibrationally mediated ammonia photodissociation in its A band

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Changjian [Key Laboratory of Mesoscopic Chemistry, School of Chemistry and Chemical Engineering, Institute of Theoretical and Computational Chemistry, Nanjing University, Nanjing 210093 (China); Zhu, Xiaolei; Yarkony, David R., E-mail: jianyi.m@gmail.com, E-mail: yarkony@jhu.edu, E-mail: dqxie@nju.edu.cn, E-mail: hguo@unm.edu [Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218 (United States); Ma, Jianyi, E-mail: jianyi.m@gmail.com, E-mail: yarkony@jhu.edu, E-mail: dqxie@nju.edu.cn, E-mail: hguo@unm.edu [Institute of Atomic and Molecular Physics, Sichuan University, Chengdu, Sichuan 610065 (China); Xie, Daiqian, E-mail: jianyi.m@gmail.com, E-mail: yarkony@jhu.edu, E-mail: dqxie@nju.edu.cn, E-mail: hguo@unm.edu [Key Laboratory of Mesoscopic Chemistry, School of Chemistry and Chemical Engineering, Institute of Theoretical and Computational Chemistry, Nanjing University, Nanjing 210093 (China); Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Guo, Hua, E-mail: jianyi.m@gmail.com, E-mail: yarkony@jhu.edu, E-mail: dqxie@nju.edu.cn, E-mail: hguo@unm.edu [Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico 87131 (United States)

    2015-03-07

    Non-adiabatic processes play an important role in photochemistry, but the mechanism for conversion of electronic energy to chemical energy is still poorly understood. To explore the possibility of vibrational control of non-adiabatic dynamics in a prototypical photoreaction, namely, the A-band photodissociation of NH{sub 3}(X{sup ~1}A{sub 1}), full-dimensional state-to-state quantum dynamics of symmetric or antisymmetric stretch excited NH{sub 3}(X{sup ~1}A{sub 1}) is investigated on recently developed coupled diabatic potential energy surfaces. The experimentally observed H atom kinetic energy distributions are reproduced. However, contrary to previous inferences, the NH{sub 2}(A{sup ~2}A{sub 1})/NH{sub 2}(X{sup ~2}B{sub 1}) branching ratio is found to be small regardless of the initial preparation of NH{sub 3}(X{sup ~1}A{sub 1}), while the internal state distribution of the preeminent fragment, NH{sub 2}(X{sup ~2}B{sub 1}), is found to depend strongly on the initial vibrational excitation of NH{sub 3}(X{sup ~1}A{sub 1}). The slow H atoms in photodissociation mediated by the antisymmetric stretch fundamental state are due to energy sequestered in the internally excited NH{sub 2}(X{sup ~2}B{sub 1}) fragment, rather than in NH{sub 2}(A{sup ~2}A{sub 1}) as previously proposed. The high internal excitation of the NH{sub 2}(X{sup ~2}B{sub 1}) fragment is attributed to the torques exerted on the molecule as it passes through the conical intersection seam to the ground electronic state of NH{sub 3}. Thus in this system, contrary to previous assertions, the control of electronic state branching by selective excitation of ground state vibrational modes is concluded to be ineffective. The juxtaposition of precise quantum mechanical results with complementary results based on quasi-classical surface hopping trajectories provides significant insights into the non-adiabatic process.

  9. Analytical chemistry instrumentation

    International Nuclear Information System (INIS)

    Laing, W.R.

    1986-01-01

    In nine sections, 48 chapters cover 1) analytical chemistry and the environment 2) environmental radiochemistry 3) automated instrumentation 4) advances in analytical mass spectrometry 5) fourier transform spectroscopy 6) analytical chemistry of plutonium 7) nuclear analytical chemistry 8) chemometrics and 9) nuclear fuel technology

  10. Fundamentals of nuclear chemistry

    International Nuclear Information System (INIS)

    Majer, V.

    1982-01-01

    The author of the book has had 25 years of experience at the Nuclear Chemistry of Prague Technical University. In consequence, the book is intended as a basic textbook for students of this field. Its main objectives are an easily understandable presentation of the complex subject and in spite of the uncertainty which still characterizes the definition and subjects of nuclear chemistry - a systematic classification and logical structure. Contents: 1. Introduction (history and definition); 2. General nuclear chemistry (physical fundamentals, hot atom chemistry, interaction of nuclear radiation with matter, radioactive elements, isotope effects, isotope exchange, chemistry of radioactive trace elements); 3. Methods of nuclear chemistry of nuclear chemistry (radiochemical methods, activation, separation and enrichment chemistry); 4. Preparative nuclear chemistry (isotope production, labelled compounds); 5. Analytival nuclear chemistry; 6. Applied nuclear chemistry (isotope applications in general physical and analytical chemistry). The book is supplemented by an annex with tables, a name catalogue and a subject index which will facilitate access to important information. (RB) [de

  11. American Association for Clinical Chemistry

    Science.gov (United States)

    ... Find the answer to your question IN CLINICAL CHEMISTRY Hs-cTnI as a Gatekeeper for Further Cardiac ... Online Harmonization.net Commission on Accreditation in Clinical Chemistry American Board of Clinical Chemistry Clinical Chemistry Trainee ...

  12. Measuring Carbon Footprint of Flexible Pavement Construction Project in Indonesia

    Science.gov (United States)

    Hatmoko, Jati Utomo Dwi; Hidayat, Arif; Setiawati, Apsari; Prasetyo, Stefanus Catur Adi

    2018-02-01

    Road infrastructure in Indonesia is mainly dominated by flexible pavement type. Its construction process, however, has raised concerns in terms of its environment impacts. This study aims to track and measure the carbon footprint of flexible pavement. The objectives are to map the construction process in relation to greenhouse gas (GHG) emissions, to quantify them in terms of carbon dioxide equivalents (CO2e) as generated by the process of production and transportation of raw materials, and the operation of plant off-site and on-site project. Data collection was done by having site observations and interviews with project stakeholders. The results show a total emissions of 70.888 tonnes CO2e, consisting of 34.248 tonnes CO2e (48.31%) off-site activities and 36.640 tonnes CO2e (51.687%) on-site activities. The two highest CO2e emissions were generated by the use of plant for asphalt concrete laying activities accounted 34.827 tonnes CO2e (49.130%), and material transportation accounted 24.921 (35.155%). These findings provide a new perspective of the carbon footprint in flexible pavement and suggest the urgent need for the use of more efficient and environmentally friendly plant in construction process as it shows the most significant contribution on the CO2e. This study provides valuable understanding on the environmental impact of typical flexible pavement projects in Indonesia, and further can be used for developing green road framework.

  13. Assessing the Ecological Footprint of Ecotourism Packages: A Methodological Proposition

    Directory of Open Access Journals (Sweden)

    Maria Serena Mancini

    2018-06-01

    Full Text Available Tourism represents a key economic sector worldwide, constituting great leverage for local economic development but also putting noticeable environmental pressures on local natural resources. Ecotourism may be a viable alternative to mass tourism to minimize impacts on ecosystems, but it needs shared sustainability standards and monitoring tools to evaluate impacts. This paper presents a first methodological proposition to calculate the environmental impact of ecotourism packages through the use of an ad-hoc, customized version of the Ecological Footprint methodology. It follows a participatory, bottom-up approach to collecting input data for the four main services (Accommodation, Food & Drinks, Activity & Service, and Mobility & Transfer provided to tourists through the use of surveys and stakeholders engagement. The outcome of our approach materializes in an excel-based ecotourism workbook capable of processing input data collected through surveys and returning Ecological Footprint values for specific ecotourism packages. Although applied to ecotourism in Mediterranean Protected Areas within the context of the DestiMED project, we believe that the methodology and approach presented here can constitute a blueprint and a benchmark for future studies dealing with the impact of ecotourism packages.

  14. Footprint Database and web services for the Herschel space observatory

    Science.gov (United States)

    Verebélyi, Erika; Dobos, László; Kiss, Csaba

    2015-08-01

    Using all telemetry and observational meta-data, we created a searchable database of Herschel observation footprints. Data from the Herschel space observatory is freely available for everyone but no uniformly processed catalog of all observations has been published yet. As a first step, we unified the data model for all three Herschel instruments in all observation modes and compiled a database of sky coverage information. As opposed to methods using a pixellation of the sphere, in our database, sky coverage is stored in exact geometric form allowing for precise area calculations. Indexing of the footprints allows for very fast search among observations based on pointing, time, sky coverage overlap and meta-data. This enables us, for example, to find moving objects easily in Herschel fields. The database is accessible via a web site and also as a set of REST web service functions which makes it usable from program clients like Python or IDL scripts. Data is available in various formats including Virtual Observatory standards.

  15. The anatomical footprint of the Achilles tendon: a cadaveric study.

    Science.gov (United States)

    Ballal, M S; Walker, C R; Molloy, A P

    2014-10-01

    We dissected 12 fresh-frozen leg specimens to identify the insertional footprint of each fascicle of the Achilles tendon on the calcaneum in relation to their corresponding muscles. A further ten embalmed specimens were examined to confirm an observation on the retrocalcaneal bursa. The superficial part of the insertion of the Achilles tendon is represented by fascicles from the medial head of the gastrocnemius muscle, which is inserted over the entire width of the inferior facet of the calcaneal tuberosity. In three specimens this insertion was in continuity with the plantar fascia in the form of periosteum. The deep part of the insertion of the Achilles tendon is made of fascicles from the soleus tendon, which insert on the medial aspect of the middle facet of the calcaneal tuberosity, while the fascicles of the lateral head of the gastrocnemius tendon insert on the lateral aspect of the middle facet of the calcaneal tuberosity. A bicameral retrocalcaneal bursa was present in 15 of the 22 examined specimens. This new observation and description of the insertional footprint of the Achilles tendon and the retrocalcaneal bursa may allow a better understanding of the function of each muscular part of the gastrosoleus complex. This may have clinical relevance in the treatment of Achilles tendinopathies. ©2014 The British Editorial Society of Bone & Joint Surgery.

  16. Atlantic Multidecadal Oscillation footprint on global high cloud cover

    Science.gov (United States)

    Vaideanu, Petru; Dima, Mihai; Voiculescu, Mirela

    2017-12-01

    Due to the complexity of the physical processes responsible for cloud formation and to the relatively short satellite database of continuous data records, cloud behavior in a warming climate remains uncertain. Identifying physical links between climate modes and clouds would contribute not only to a better understanding of the physical processes governing their formation and dynamics, but also to an improved representation of the clouds in climate models. Here, we identify the global footprint of the Atlantic Multidecadal Oscillation (AMO) on high cloud cover, with focus on the tropical and North Atlantic, tropical Pacific and on the circum-Antarctic sector. In the tropical band, the sea surface temperature (SST) and high cloud cover (HCC) anomalies are positively correlated, indicating a dominant role played by convection in mediating the influence of the AMO-related SST anomalies on the HCC field. The negative SST-HCC correlation observed in North Atlantic could be explained by the reduced meridional temperature gradient induced by the AMO positive phase, which would be reflected in less storms and negative HCC anomalies. A similar negative SST-HCC correlation is observed around Antarctica. The corresponding negative correlation around Antarctica could be generated dynamically, as a response to the intensified upward motion in the Ferrel cell. Despite the inherent imperfection of the observed and reanalysis data sets, the AMO footprint on HCC is found to be robust to the choice of dataset, statistical method, and specific time period considered.

  17. Water footprints of cities - indicators for sustainable consumption and production

    Science.gov (United States)

    Hoff, H.; Döll, P.; Fader, M.; Gerten, D.; Hauser, S.; Siebert, S.

    2014-01-01

    Water footprints have been proposed as sustainability indicators, relating the consumption of goods like food to the amount of water necessary for their production and the impacts of that water use in the source regions. We further developed the existing water footprint methodology, by globally resolving virtual water flows from production to consumption regions for major food crops at 5 arcmin spatial resolution. We distinguished domestic and international flows, and assessed local impacts of export production. Applying this method to three exemplary cities, Berlin, Delhi and Lagos, we find major differences in amounts, composition, and origin of green and blue virtual water imports, due to differences in diets, trade integration and crop water productivities in the source regions. While almost all of Delhi's and Lagos' virtual water imports are of domestic origin, Berlin on average imports from more than 4000 km distance, in particular soy (livestock feed), coffee and cocoa. While 42% of Delhi's virtual water imports are blue water based, the fractions for Berlin and Lagos are 2 and 0.5%, respectively, roughly equal to the water volumes abstracted in these two cities for domestic water use. Some of the external source regions of Berlin's virtual water imports appear to be critically water scarce and/or food insecure. However, for deriving recommendations on sustainable consumption and trade, further analysis of context-specific costs and benefits associated with export production will be required.

  18. Grip Analysis of Road Surface and Tire Footprint Using FEM

    Science.gov (United States)

    Sabri, M.; Abda, S.

    2018-02-01

    Road grip involve a touch between road pavement and the tire tread pattern. The load bearing surface, which depends on pavement roughness and local pressures in the contact patch. This research conducted to develop a Finite element model for simulating the experimentally testing of asphalt in Jl. AH Nasution Medan, North Sumatera Indonesia base on the value of grip coefficient from various tire loads and the various speed of the vehicle during contact to the road. A tire model and road pavement are developed for the analyses the geometry of tire footprint. The results showed that the greater the mass of car will increase grip coefficient. The coefficient of grip on the road surface contact trough the tire footprint strongly influence the kinetic coefficient of friction at certain speeds. Experimentally show that Concrete road grip coefficient of more than 34% compared to the asphalt road at the same IRI parameters (6-8). Kinetic friction coefficient more than 0.33 was obtained in a asphalt path at a speed of 30-40 Km/hour.

  19. Carbon nanotube transistors scaled to a 40-nanometer footprint.

    Science.gov (United States)

    Cao, Qing; Tersoff, Jerry; Farmer, Damon B; Zhu, Yu; Han, Shu-Jen

    2017-06-30

    The International Technology Roadmap for Semiconductors challenges the device research community to reduce the transistor footprint containing all components to 40 nanometers within the next decade. We report on a p-channel transistor scaled to such an extremely small dimension. Built on one semiconducting carbon nanotube, it occupies less than half the space of leading silicon technologies, while delivering a significantly higher pitch-normalized current density-above 0.9 milliampere per micrometer at a low supply voltage of 0.5 volts with a subthreshold swing of 85 millivolts per decade. Furthermore, we show transistors with the same small footprint built on actual high-density arrays of such nanotubes that deliver higher current than that of the best-competing silicon devices under the same overdrive, without any normalization. We achieve this using low-resistance end-bonded contacts, a high-purity semiconducting carbon nanotube source, and self-assembly to pack nanotubes into full surface-coverage aligned arrays. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

  20. Carbon footprint and cost-effectiveness of cataract surgery.

    Science.gov (United States)

    Venkatesh, Rengaraj; van Landingham, Suzanne W; Khodifad, Ashish M; Haripriya, Aravind; Thiel, Cassandra L; Ramulu, Pradeep; Robin, Alan L

    2016-01-01

    This article raises awareness about the cost-effectiveness and carbon footprint of various cataract surgery techniques, comparing their relative carbon emissions and expenses: manual small-incision cataract surgery (MSICS), phacoemulsification, and femtosecond laser-assisted cataract surgery. As the most commonly performed surgical procedure worldwide, cataract surgery contributes significantly to global climate change. The carbon footprint of a single phacoemulsification cataract surgery is estimated to be comparable to that of a typical person's life for 1 week. Phacoemulsification has been estimated to be between 1.4 and 4.7 times more expensive than MSICS; however, given the lower degree of postoperative astigmatism and other potential complications, phacoemulsification may still be preferable to MSICS in relatively resource-rich settings requiring high levels of visual function. Limited data are currently available regarding the environmental and financial impact of femtosecond laser-assisted cataract surgery; however, in its current form, it appears to be the least cost-effective option. Cataract surgery has a high value to patients. The relative environmental impact and cost of different types of cataract surgery should be considered as this treatment becomes even more broadly available globally and as new technologies are developed and implemented.

  1. Hydrocarbon footprints as a record of bumblebee flower visitation.

    Science.gov (United States)

    Witjes, Sebastian; Eltz, Thomas

    2009-11-01

    Bumblebees leave traces of cuticular hydrocarbons on flowers they visit, with the amount deposited being positively related to the number of visits. We asked whether such footprint hydrocarbons are retained on flowers for sufficiently long periods of time so as to reflect bee visitation in pollination studies. In laboratory experiments, flower corollae (Primula veris, Digitalis grandiflora) visited by Bombus terrestris workers retained bee-derived nonacosenes (C(29)H(58)) in near-unchanged quantities for 24 hours, both at 15 and 25 degrees C. Additionally, synthetic (Z)-9-tricosene applied to flower corollae of the deadnettle Lamium maculatum was retained for 48 hours in an unchanged quantity. In a field survey, the amount of footprint alkenes on flowers of comfrey (Symphytum officinale) plants was positively correlated with the number of bumblebee visits that those plants had received during the day. Together, these data suggest that flowers retain a long-term quantitative record of bumblebee visitation. The analysis of petal extracts by gas chromatography could provide a cheap and reliable way of quantifying bumblebee visits in landscape scale studies of pollination.

  2. Limitations of carbon footprint as indicator of environmental sustainability.

    Science.gov (United States)

    Laurent, Alexis; Olsen, Stig I; Hauschild, Michael Z

    2012-04-03

    Greenhouse gas accountings, commonly referred to with the popular term carbon footprints (CFP), are a widely used metric of climate change impacts and the main focus of many sustainability policies among companies and authorities. However, environmental sustainability concerns not just climate change but also other environmental problems, like chemical pollution or depletion of natural resources, and the focus on CFP brings the risk of problem shifting when reductions in CFP are obtained at the expense of increase in other environmental impacts. But how real is this risk? Here, we model and analyze the life cycle impacts from about 4000 different products, technologies, and services taken from several sectors, including energy generation, transportation, material production, infrastructure, and waste management. By investigating the correlations between the CFP and 13 other impact scores, we show that some environmental impacts, notably those related to emissions of toxic substances, often do not covary with climate change impacts. In such situations, carbon footprint is a poor representative of the environmental burden of products, and environmental management focused exclusively on CFP runs the risk of inadvertently shifting the problem to other environmental impacts when products are optimized to become more "green". These findings call for the use of more broadly encompassing tools to assess and manage environmental sustainability.

  3. Variability of footprint ridge density and its use in estimation of sex in forensic examinations.

    Science.gov (United States)

    Krishan, Kewal; Kanchan, Tanuj; Pathania, Annu; Sharma, Ruchika; DiMaggio, John A

    2015-10-01

    The present study deals with a comparatively new biometric parameter of footprints called footprint ridge density. The study attempts to evaluate sex-dependent variations in ridge density in different areas of the footprint and its usefulness in discriminating sex in the young adult population of north India. The sample for the study consisted of 160 young adults (121 females) from north India. The left and right footprints were taken from each subject according to the standard procedures. The footprints were analysed using a 5 mm × 5 mm square and the ridge density was calculated in four different well-defined areas of the footprints. These were: F1 - the great toe on its proximal and medial side; F2 - the medial ball of the footprint, below the triradius (the triradius is a Y-shaped group of ridges on finger balls, palms and soles which forms the basis of ridge counting in identification); F3 - the lateral ball of the footprint, towards the most lateral part; and F4 - the heel in its central part where the maximum breadth at heel is cut by a perpendicular line drawn from the most posterior point on heel. This value represents the number of ridges in a 25 mm(2) area and reflects the ridge density value. Ridge densities analysed on different areas of footprints were compared with each other using the Friedman test for related samples. The total footprint ridge density was calculated as the sum of the ridge density in the four areas of footprints included in the study (F1 + F2 + F3 + F4). The results show that the mean footprint ridge density was higher in females than males in all the designated areas of the footprints. The sex differences in footprint ridge density were observed to be statistically significant in the analysed areas of the footprint, except for the heel region of the left footprint. The total footprint ridge density was also observed to be significantly higher among females than males. A statistically significant correlation

  4. The New Color of Chemistry: Green Chemistry

    Directory of Open Access Journals (Sweden)

    Zuhal GERÇEK

    2012-01-01

    Full Text Available Green chemistry which is the new application of chemistry rules provides solutions to problems that mankind is faced with climate changes, sustainable agriculture, energy, toxics, depletion of natural sources e.g. designing new chemicals and processes that production and utilization of hazardous matters. So, it is the indispensible tool for sustainable development. Current and future chemists should consider the human health and ecological issues in their professional life. In order to provide a solution for this requirement, green chemistry rules and under standings should be primarily taken in the university curriculum and at all educational levels.

  5. Surface chemistry essentials

    CERN Document Server

    Birdi, K S

    2013-01-01

    Surface chemistry plays an important role in everyday life, as the basis for many phenomena as well as technological applications. Common examples range from soap bubbles, foam, and raindrops to cosmetics, paint, adhesives, and pharmaceuticals. Additional areas that rely on surface chemistry include modern nanotechnology, medical diagnostics, and drug delivery. There is extensive literature on this subject, but most chemistry books only devote one or two chapters to it. Surface Chemistry Essentials fills a need for a reference that brings together the fundamental aspects of surface chemistry w

  6. Fundamentals of reactor chemistry

    International Nuclear Information System (INIS)

    Akatsu, Eiko

    1981-12-01

    In the Nuclear Engineering School of JAERI, many courses are presented for the people working in and around the nuclear reactors. The curricula of the courses contain also the subject material of chemistry. With reference to the foreign curricula, a plan of educational subject material of chemistry in the Nuclear Engineering School of JAERI was considered, and the fundamental part of reactor chemistry was reviewed in this report. Since the students of the Nuclear Engineering School are not chemists, the knowledge necessary in and around the nuclear reactors was emphasized in order to familiarize the students with the reactor chemistry. The teaching experience of the fundamentals of reactor chemistry is also given. (author)

  7. Reply to Ridoutt and Huang: From water footprint assessment to policy

    NARCIS (Netherlands)

    Hoekstra, Arjen Y.; Mekonnen, Mesfin

    2012-01-01

    According to Ridoutt and Huang (1), “environmental relevance must be taken into consideration if water footprints are to inform wise decision making and policy development.” Indeed, reduction targets regarding water footprints (WFs) within catchments should be formulated on the basis of relative

  8. Barriers to Mitigate Carbon Footprint in a Selected Academic Institution in Bacoor City, Cavite, Philippines

    Science.gov (United States)

    Adanza, Jonathan R.

    2016-01-01

    Carbon footprint is an environmental menace that needs to be addressed at once. Various mitigating measures were proposed and yet manifestations of its proliferation are very much observable. This study seeks to determine primarily the barriers of non-adherence to identified measures to mitigate carbon footprint in the environment. Using the mixed…

  9. Future electricity: the challenge of reducing both carbon and water footprint

    NARCIS (Netherlands)

    Mekonnen, Mesfin; Gerbens-Leenes, Winnie; Hoekstra, Arjen Ysbert

    2016-01-01

    We estimate the consumptive water footprint (WF) of electricity and heat in 2035 for the four energy scenarios of the International Energy Agency (IEA) and a fifth scenario with a larger percentage of solar energy. Counter-intuitively, the ‘greenest’ IEA scenario (with the smallest carbon footprint)

  10. Comparison of the carbon footprint of different patient diets in a Spanish hospital.

    Science.gov (United States)

    Vidal, Rosario; Moliner, Enrique; Pikula, Andrej; Mena-Nieto, Angel; Ortega, Agustín

    2015-01-01

    Mitigating climate change requires management strategies to reduce greenhouse gas emissions in any sector, including the health system. Carbon footprint calculations should play a key role in quantifying and communicating these emissions. Food is among the categories with low accuracy because the carbon footprint for food is still under development. We aimed to quantify the carbon footprint of different diets. Average carbon footprint for a normal diet was based on detailed composition data in Juan Ramón Jiménez Hospital (Huelva, Spain). In addition, the carbon footprints of 17 other therapeutic diets were estimated using a streamlined variation of each diet published by Benidorm Clinical Hospital (Spain). The carbon footprint was calculated for 18 hospital diets for a variety of patients. The reference menu corresponds to the normal diet provided to patients who do not have special dietary requirements. This menu has a low carbon footprint of 5.083 CO₂ eq/day. Hospital diets contribute to the carbon footprint of a hospital. The type of diet has a significant impact on the greenhouse gas emissions. A Mediterranean diet is associated with lower environmental impact than diets with more meat, in particular red meat. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  11. Measuring sustainability. Why the ecological footprint is bad economics and bad environmental science

    Energy Technology Data Exchange (ETDEWEB)

    Fiala, Nathan [Department of Economics, University of California, Irvine, 3151 Social Science Plaza, Irvine, CA 92697-5100 (United States)

    2008-11-01

    The ecological footprint is a measure of the resources necessary to produce the goods that an individual or population consumes. It is also used as a measure of sustainability, though evidence suggests that it falls short. The assumptions behind footprint calculations have been extensively criticized; I present here further evidence that it fails to satisfy simple economic principles because the basic assumptions are contradicted by both theory and historical data. Specifically, I argue that the footprint arbitrarily assumes both zero greenhouse gas emissions, which may not be ex ante optimal, and national boundaries, which makes extrapolating from the average ecological footprint problematic. The footprint also cannot take into account intensive production, and so comparisons to biocapacity are erroneous. Using only the assumptions of the footprint then, one could argue that the Earth can sustain greatly increased production, though there are important limitations that the footprint cannot address, such as land degradation. Finally, the lack of correlation between land degradation and the ecological footprint obscures the effects of a larger sustainability problem. Better measures of sustainability would address these issues directly. (author)

  12. The green, blue and grey water footprint of crops and derived crop products

    NARCIS (Netherlands)

    Mekonnen, Mesfin; Hoekstra, Arjen Ysbert

    2011-01-01

    This study quantifies the green, blue and grey water footprint of global crop production in a spatially-explicit way for the period 1996–2005. The assessment improves upon earlier research by taking a high-resolution approach, estimating the water footprint of 126 crops at a 5 by 5 arc minute grid.

  13. Water footprint, extended water footprint and virtual water trade of the Cantabria region, Spain. A critical appraisal of results, uncertainties and methods.

    Science.gov (United States)

    Diaz-Alcaide, Silvia; Martinez-Santos, Pedro; Willaarts, Barbara; Hernández-Moreno, Enrique; Llamas, M. Ramon

    2015-04-01

    Water footprint assessments have gradually gained recognition as valuable tools for water management, to the point that they have been officially incorporated to water planning in countries such as Spain. Adequate combinations of the virtual water and water footprint concepts present the potential to link a broad range of sectors and issues, thus providing appropriate frameworks to support optimal water allocation and to inform production and trade decisions from the water perspective. We present the results of a regional study carried out in Cantabria, a 5300 km2 autonomous region located in northern Spain. Our approach deals with the municipal, shire and regional scales, combining different methods to assess each of the main components of Cantabria's water footprint (agriculture, livestock, forestry, industry, mining, tourism, domestic use and reservoirs), as well as exploring the significance of different approaches, assumptions and databases in the overall outcomes. The classic water footprint method is coupled with extended water footprint analyses in order to provide an estimate of the social and economic value of each sector. Finally, virtual water imports and exports are computed between Cantabria and the rest of Spain and between Cantabria and the world. The outcome of our work (a) highlights the paramount importance of green water (mostly embedded in pastures) in the region's water footprint and virtual water exports; (b) establishes the role of the region as a net virtual water exporter; (c) shows the productivity of water (euro/m3 and jobs/m3) to be highest in tourism and lowest in agriculture and livestock; and (d) demonstrates that statistical databases are seldom compiled with water footprint studies in mind, which is likely to introduce uncertainties in the results. Although our work shows that there is still plenty of room for improvement in regional-scale water footprint assessments, we contend that the available information is sufficient to

  14. Annual report 1985 Chemistry Department

    International Nuclear Information System (INIS)

    Funck, J.; Larsen, E.; Nielsen, O.J.

    1986-03-01

    This report contains a brief survey of the main activities in the Chemistry Department. All particles and reports published and lectures given in 1985 are presented. The facilities and equipment are mentioned briefly. The activities are divided into the following groups: radioisotope chemistry, analytical- and organic chemistry, environmental chemistry, polymer chemistry, geochemistry and waste disposal, radical chemistry, positron annihilation, mineral processing, and general. (author)

  15. Annual report 1984 Chemistry Department

    International Nuclear Information System (INIS)

    Funck, J.; Larsen, E.; Nielsen, O.J.

    1985-03-01

    This report contains a brief survey of the main activities in the Chemistry Department. All articles and reports published and lectures given in 1984 are presented. The facilities and equipment are mentioned briefly. The activities are divided into the following groups: radioisotope chemistry, analytical- and organic chemistry , environmental chemistry, polymer chemistry, geochemistry and waste disposal, radical chemistry, positron annihilation, mineral processing, and general. (author)

  16. Spontaneous Isomerization of Peptide Cation Radicals Following Electron Transfer Dissociation Revealed by UV-Vis Photodissociation Action Spectroscopy.

    Science.gov (United States)

    Imaoka, Naruaki; Houferak, Camille; Murphy, Megan P; Nguyen, Huong T H; Dang, Andy; Tureček, František

    2018-01-16

    Peptide cation radicals of the z-type were produced by electron transfer dissociation (ETD) of peptide dications and studied by UV-Vis photodissociation (UVPD) action spectroscopy. Cation radicals containing the Asp (D), Asn (N), Glu (E), and Gln (Q) residues were found to spontaneously isomerize by hydrogen atom migrations upon ETD. Canonical N-terminal [z 4 + H] +● fragment ion-radicals of the R-C ● H-CONH- type, initially formed by N-C α bond cleavage, were found to be minor components of the stable ion fraction. Vibronically broadened UV-Vis absorption spectra were calculated by time-dependent density functional theory for several [ ● DAAR + H] + isomers and used to assign structures to the action spectra. The potential energy surface of [ ● DAAR + H] + isomers was mapped by ab initio and density functional theory calculations that revealed multiple isomerization pathways by hydrogen atom migrations. The transition-state energies for the isomerizations were found to be lower than the dissociation thresholds, accounting for the isomerization in non-dissociating ions. The facile isomerization in [ ● XAAR + H] + ions (X = D, N, E, and Q) was attributed to low-energy intermediates having the radical defect in the side chain that can promote hydrogen migration along backbone C α positions. A similar side-chain mediated mechanism is suggested for the facile intermolecular hydrogen migration between the c- and [z + H] ● -ETD fragments containing Asp, Asn, Glu, and Gln residues. Graphical Abstract ᅟ.

  17. Gas phase structures and charge localization in small aluminum oxide anions: Infrared photodissociation spectroscopy and electronic structure calculations

    Energy Technology Data Exchange (ETDEWEB)

    Song, Xiaowei; Fagiani, Matias R. [Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D-14195 Berlin (Germany); Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linnéstrasse 2, D-04103 Leipzig (Germany); Gewinner, Sandy; Schöllkopf, Wieland [Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D-14195 Berlin (Germany); Asmis, Knut R., E-mail: knut.asmis@uni-leipzig.de, E-mail: js@chemie.hu-berlin.de [Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linnéstrasse 2, D-04103 Leipzig (Germany); Bischoff, Florian A.; Berger, Fabian; Sauer, Joachim, E-mail: knut.asmis@uni-leipzig.de, E-mail: js@chemie.hu-berlin.de [Institut für Chemie, Humboldt-Universität zu Berlin, Unter den Linden 6, D-10099 Berlin (Germany)

    2016-06-28

    We use cryogenic ion trap vibrational spectroscopy in combination with quantum chemical calculations to study the structure of mono- and dialuminum oxide anions. The infrared photodissociation spectra of D{sub 2}-tagged AlO{sub 1-4}{sup −} and Al{sub 2}O{sub 3-6}{sup −} are measured in the region from 400 to 1200 cm{sup −1}. Structures are assigned based on a comparison to simulated harmonic and anharmonic IR spectra derived from electronic structure calculations. The monoaluminum anions contain an even number of electrons and exhibit an electronic closed-shell ground state. The Al{sub 2}O{sub 3-6}{sup −} anions are oxygen-centered radicals. As a result of a delicate balance between localization and delocalization of the unpaired electron, only the BHLYP functional is able to qualitatively describe the observed IR spectra of all species with the exception of AlO{sub 3}{sup −}. Terminal Al–O stretching modes are found between 1140 and 960 cm{sup −1}. Superoxo and peroxo stretching modes are found at higher (1120-1010 cm{sup −1}) and lower energies (850-570 cm{sup −1}), respectively. Four modes in-between 910 and 530 cm{sup −1} represent the IR fingerprint of the common structural motif of dialuminum oxide anions, an asymmetric four-member Al–(O){sub 2}–Al ring.

  18. Picosecond dynamics of reactions in the liquid phase: studies of iodine photodissociation and development of new laser techniques

    International Nuclear Information System (INIS)

    Berg, M.A.

    1985-09-01

    Iodine photodissociation and recombination was studied as a model for processes common to chemical reaction in the liquid phase. Picosecond transient absorption measurements from 1000 to 295 nm were used to monitor the dynamics in a variety of solvents. Most of the atoms which undergo geminate recombination were found to do so in less than or equal to 15 ps, in agreement with the results of existing molecular dynamics simulations. Vibrational relaxation times vary from approx.15 ps near the middle of the ground state well to approx.150 ps for complete relaxation to v = 0. The prediction of strong resonant vibrational energy transfer to chlorinated methane solvents was not supported, but some evidence for this mechanism was found for alkane solvents. Current theory is unable to explain the large variation (65 to 2700 ps) of the excited A'-state lifetime in various solvents. The 10-Hz amplified, synchronously-pumped dye laser which was used in these studies is described and characterized. SERS (Stimulated Electronic Raman Scattering) and difference frequency mixing were used in the generation of the infrared and far-infrared, respectively. 54 refs., 38 figs., 3 tabs

  19. Spontaneous Isomerization of Peptide Cation Radicals Following Electron Transfer Dissociation Revealed by UV-Vis Photodissociation Action Spectroscopy

    Science.gov (United States)

    Imaoka, Naruaki; Houferak, Camille; Murphy, Megan P.; Nguyen, Huong T. H.; Dang, Andy; Tureček, František

    2018-01-01

    Peptide cation radicals of the z-type were produced by electron transfer dissociation (ETD) of peptide dications and studied by UV-Vis photodissociation (UVPD) action spectroscopy. Cation radicals containing the Asp (D), Asn (N), Glu (E), and Gln (Q) residues were found to spontaneously isomerize by hydrogen atom migrations upon ETD. Canonical N-terminal [z4 + H]+● fragment ion-radicals of the R-C●H-CONH- type, initially formed by N-Cα bond cleavage, were found to be minor components of the stable ion fraction. Vibronically broadened UV-Vis absorption spectra were calculated by time-dependent density functional theory for several [●DAAR + H]+ isomers and used to assign structures to the action spectra. The potential energy surface of [●DAAR + H]+ isomers was mapped by ab initio and density functional theory calculations that revealed multiple isomerization pathways by hydrogen atom migrations. The transition-state energies for the isomerizations were found to be lower than the dissociation thresholds, accounting for the isomerization in non-dissociating ions. The facile isomerization in [●XAAR + H]+ ions (X = D, N, E, and Q) was attributed to low-energy intermediates having the radical defect in the side chain that can promote hydrogen migration along backbone Cα positions. A similar side-chain mediated mechanism is suggested for the facile intermolecular hydrogen migration between the c- and [z + H]●-ETD fragments containing Asp, Asn, Glu, and Gln residues. [Figure not available: see fulltext.

  20. Photodissociation dynamics of H2O at 111.5 nm by a vacuum ultraviolet free electron laser

    Science.gov (United States)

    Wang, Heilong; Yu, Yong; Chang, Yao; Su, Shu; Yu, Shengrui; Li, Qinming; Tao, Kai; Ding, Hongli; Yang, Jaiyue; Wang, Guanglei; Che, Li; He, Zhigang; Chen, Zhichao; Wang, Xingan; Zhang, Weiqing; Dai, Dongxu; Wu, Guorong; Yuan, Kaijun; Yang, Xueming

    2018-03-01

    Photodissociation dynamics of H2O via the F ˜ state at 111.5 nm were investigated using the high resolution H-atom Rydberg "tagging" time-of-flight (TOF) technique, in combination with the tunable vacuum ultraviolet free electron laser at the Dalian Coherent Light Source. The product translational energy distributions and angular distributions in both parallel and perpendicular directions were derived from the recorded TOF spectra. Based on these distributions, the quantum state distributions and angular anisotropy parameters of OH (X) and OH (A) products have been determined. For the OH (A) + H channel, highly rotationally excited OH (A) products have been observed. These products are ascribed to a fast direct dissociation on the B ˜ 1A1 state surface after multi-step internal conversions from the initial excited F ˜ state to the B ˜ state. While for the OH (X) + H channel, very highly rotationally excited OH (X) products with moderate vibrational excitation are revealed and attributed to the dissociation via a nonadiabatic pathway through the well-known two conical intersections between the B ˜ -state and the X ˜ -state surfaces.