WorldWideScience

Sample records for secondary hydrocarbon migration

  1. Hydrocarbon migration and accumulation in the Upper Cretaceous Qingshankou Formation, Changling Sag, southern Songliao Basin: Insights from integrated analyses of fluid inclusion, oil source correlation and basin modelling

    Science.gov (United States)

    Dong, Tian; He, Sheng; Wang, Dexi; Hou, Yuguang

    2014-08-01

    The Upper Cretaceous Qingshankou Formation acts as both the source and reservoir sequence in the Changling Sag, situated in the southern end of the Songliao Basin, northeast China. An integrated approach involving determination of hydrocarbon charging history, oil source correlation and hydrocarbon generation dynamic modeling was used to investigate hydrocarbon migration processes and further predict the favorable targets of hydrocarbon accumulations in the Qingshankou Formation. The hydrocarbon generation and charge history was investigated using fluid inclusion analysis, in combination with stratigraphic burial and thermal modeling. The source rocks began to generate hydrocarbons at around 82 Ma and the hydrocarbon charge event occurred from approximately 78 Ma to the end of Cretaceous (65.5 Ma) when a large tectonic uplift took place. Correlation of stable carbon isotopes of oils and extracts of source rocks indicates that oil was generated mainly from the first member of Qingshankou Formation (K2qn1), suggesting that hydrocarbon may have migrated vertically. Three dimensional (3D) petroleum system modeling was used to evaluate the processes of secondary hydrocarbon migration in the Qingshankou Formation since the latest Cretaceous. During the Late Cretaceous, hydrocarbon, mainly originated from the Qianan depression, migrated laterally to adjacent structural highs. Subsequent tectonic inversion, defined as the late Yanshan Orogeny, significantly changed hydrocarbon migration patterns, probably causing redistribution of primary hydrocarbon reservoirs. In the Tertiary, the Heidimiao depression was buried much deeper than the Qianan depression and became the main source kitchen. Hydrocarbon migration was primarily controlled by fluid potential and generally migrated from relatively high potential areas to low potential areas. Structural highs and lithologic transitions are potential traps for current oil and gas exploration. Finally, several preferred hydrocarbon accumulation sites have been identified by this work, like Western Slope, Southern uplift, and Eastern Slope, helping reduce the risk on targeting hydrocarbon potential reservoirs in Changling Sag.

  2. Arsenic cycling in hydrocarbon plumes: secondary effects of natural attenuation

    Science.gov (United States)

    Cozzarelli, Isabelle M.; Schreiber, Madeline E.; Erickson, Melinda L.; Ziegler, Brady A.

    2015-01-01

    Monitored natural attenuation is widely applied as a remediation strategy at hydrocarbon spill sites. Natural attenuation relies on biodegradation of hydrocarbons coupled with reduction of electron acceptors, including solid phase ferric iron (Fe(III)). Because arsenic (As) adsorbs to Fe-hydroxides, a potential secondary effect of natural attenuation of hydrocarbons coupled with Fe(III) reduction is a release of naturally occurring As to groundwater. At a crude-oil-contaminated aquifer near Bemidji, Minnesota, anaerobic biodegradation of hydrocarbons coupled to Fe(III) reduction has been well documented. We collected groundwater samples at the site annually from 2009 to 2013 to examine if As is released to groundwater and, if so, to document relationships between As and Fe inside and outside of the dissolved hydrocarbon plume. Arsenic concentrations in groundwater in the plume reached 230?µg/L, whereas groundwater outside the plume contained less than 5?µg/L As. Combined with previous data from the Bemidji site, our results suggest that (1) naturally occurring As is associated with Fe-hydroxides present in the glacially derived aquifer sediments; (2) introduction of hydrocarbons results in reduction of Fe-hydroxides, releasing As and Fe to groundwater; (3) at the leading edge of the plume, As and Fe are removed from groundwater and retained on sediments; and (4) downgradient from the plume, patterns of As and Fe in groundwater are similar to background. We develop a conceptual model of secondary As release due to natural attenuation of hydrocarbons that can be applied to other sites where an influx of biodegradable organic carbon promotes Fe(III) reduction.

  3. Isotopic evidence for biological controls on migration of petroleum hydrocarbons

    International Nuclear Information System (INIS)

    The isotopic compositions of potential metabolic byproducts of petroleum hydrocarbon biodegradation in soil gas and groundwater samples from a shallow plume of aviation gas (AVGAS) were analyzed to assess levels and pathways of intrinsic bioremediation occurring at the site. Gasoline range organic compounds (GROs) in soil gas samples from the original source area were low (4 was > 20% in the central part of the plume and correlated well with GRO concentrations. The 14C contents of the CH4, associated soil gas CO2 and dissolved inorganic carbon compounds (DIC) in the groundwater were all less than 0.1 times modern, indicating they were primarily formed from degradation of AVGAS and not other potential carbon sources such as degradation of natural organic matter or dissolution of carbonate shells. The deltaD and delta13C values of the CH4 indicate that it was produced via acetate fermentation. The delta13C values of CO2 and DIC in the central part of the plume were high, suggesting that a large fraction of the CO2 in that area was also produced by acetate fermentation. At the down-gradient edges of the plume, CH4 levels dropped to zero and the delta13C values of CO2 were much lower (-26l), indicating that aerobic degradation of the AVGAating that aerobic degradation of the AVGAS was dominant in this area. Beyond the down-gradient edges of the plume, the 14C contents of both groundwater DIC and soil gas CO2 were significantly below modern levels, implying that most of the carbon there was derived from hydrocarbons and had migrated beyond the edge of the plume. These data show that methanogenic activity in the central part of the plume was slowly degrading the AVGAS, but aerobic activity at the edges of the plume was effectively limiting migration of the hydrocarbons. (author)

  4. Importance des phénomènes de migration verticale des hydrocarbures Significance of Vertical Migration Phenomea of Hydrocarbons

    Directory of Open Access Journals (Sweden)

    Chiarelle A.

    2006-11-01

    Full Text Available Cette publication a pour but de démonter les mécanismes de migration verticale des hydrocarbures et d'en analyser les conséquences, à partir d'exemples concrets choisis sur les domaines d'activité de la Société Nationale Elf Aquitaine (Production [SNEA (PJ. Les hydrocarbures, huile et gaz, rassemblés en phase individualisée évoluent dans un milieu poreux, fin, généralement mouillé à l'eau. Dans un tel environnement la migration suppose des pressions capillaires élevées. On démontre que cette condition se realise plus particulièrement sur Ies zones hautes fermées où les élements d'hydrocarbures expulses de la roche mère peuvent se rassembler en amas de taille importante, développant une forte poussee d'Archimède. De même le gaz, du fait de sa masse volumique faible par rapport à celle de l'eau, manifestera une grande aptitude à la migration verticale, ce qui conduira souvent à une redistribution verticale des hydrocarbures non conforme au schéma diagénétique classique : présence d'un gisement de gaz en surface et huile en profondeur. Combinés à l'effet Gussow, phénomène de refoulement de l'huile par le gaz hors de la fermeture critique d'une structure, les processus envisagés ici, où tes accidents tectoniques tiennent une place importante, aboutiront généralement à sil: aerer spatialement l'huile et le gaz. Ces transferts semblent s'accompagner fréquemment de modifications dans la composition chimique des huiles : augmentation des teneurs en soufre, en métaux traces, en hydrocarbures aromatiques, et alourdissement des huiles The purpose of this article is ta described the vertical migration mechanisms of hydrocarbons and to analyze their conséquences, on the basis of concrete examples selected in the fields of activities carried on by Société Nationale Elf Aquitaine (SNEA. When hydrocarbons (ai( and gas are gathered in a distinct phase, they evolve in a fine porous medium that is usually water wet. In such on environment, migration requires high capillary pressures. lt is shown that such conditions occur especially in high closed zones where the hydrocarbons driven out of the source rock con gather together in a large-sized mass, thus building up a high degree of buoyancy. In the same way, because gas has a louver specific gravity thon water, it has a great tendency ta migrote vertically, which often brings about a vertical redistribution of hydrocarbons that does not conform ta the conventional diagenetic pattern, i. e. the presence of a gas pool above a deeper ail pool.

  5. Hydrocarbon solubility and its migration processes: a look at the present status

    Energy Technology Data Exchange (ETDEWEB)

    Mamun, C.K.; Ohkuma, H.; Sepehrnoori, K.

    1985-12-01

    In this study we review the present status of knowledge of solubility of hydrocarbons and its implications on primary migration processes. The intent is to examine the solubility and the transportation mechanisms relevant to geopressured-geothermal reservoirs, although the discussion included here accommodates a wide range of related aspects. Influences of parameters associated with hydrocarbon (especially methane) solubility have been studied. We have sought to evaluate several primary hydrocarbon migration processes and to point out their attractive features as well as their limitations. A brief discussion of hydrocarbon generation processes is also included.

  6. Secondary organic aerosol from polycyclic aromatic hydrocarbons in Southeast Texas

    Science.gov (United States)

    Zhang, Hongliang; Ying, Qi

    2012-08-01

    Recent chamber studies show that low-volatility gas phase precursors such as polycyclic aromatic hydrocarbons (PAHs) can be a significant source of secondary organic aerosol (SOA). In this work, formation of SOA from the photo-oxidation products of PAHs is added to the SOA modeling framework of the Community Multiscale Air Quality (CMAQ) model to determine the regional distribution of SOA products from PAHs (PAH-SOA) and the contributions from sources in Southeast Texas during the Texas Air Quality Study 2006 (TexAQS 2006). Results show that PAHs released from anthropogenic sources can produce SOA mass as much as 10% of that from the traditional light aromatics or approximately 4% of total anthropogenic SOA. In areas under the influence of wildfire emissions, the amount of PAH-SOA can be as much as 50% of the SOA from light aromatics. A source-oriented modeling framework is adopted to determine the major sources of PAH-SOA by tracking the emitted PAHs and their oxidation products in the gas and aerosol phases from different sources separately. Among the eight sources (vehicles, solvent utilization, residential wood, industries, natural gas combustion, coal combustion, wildfire and other sources) that are tracked in the model, wildfire, vehicles, solvent and industries are the major sources of PAH-SOA. Coal and natural gas combustion appear to be less important in terms of their contributions to PAH-SOA.

  7. A Review of Laboratory and Numerical Simulations of Hydrocarbons Migration in Subsurface Environments

    Directory of Open Access Journals (Sweden)

    M.P. Zakaria

    2011-01-01

    Full Text Available The leaking from underground storage and surface spills of various hydrocarbon sources has caused the hazardous subsurface contamination. The toxic compounds of chemicals have made field study infeasible and it has been replaced by laboratory and numerical simulations. This study introduces the methodology for two-dimensional non-aqueous phase liquid experiments with the application of light reflection and light transmission methods associated with image analysis methods. In addition, this study emphasizes the experiments with numerical simulations in which data acquisition is essential for verification and validation of numerical models. The numerical efforts are supported by basic formulation, with existing codes and its application for light hydrocarbon migration simulation. Overall, this study discussed the laboratory works and numerical simulations using current visualization techniques and makes suggestions for future research.

  8. Chemometric characterization of the hydrogen bonding complexes of secondary amides and aromatic hydrocarbons

    Directory of Open Access Journals (Sweden)

    Jovi? Branislav

    2012-01-01

    Full Text Available The paper reports the results of the study of hydrogen bonding complexes between secondary amides and various aromatic hydrocarbons. The possibility of using chemometric methods was investigated in order to characterize N-H•••? hydrogen bonded complexes. Hierarchical clustering and Principal Component Analysis (PCA have been applied on infrared spectroscopic and Taft parameters of 43 N-substituted amide complexes with different aromatic hydrocarbons. Results obtained in this report are in good agreement with conclusions of other spectroscopic and thermodynamic analysis.

  9. The Role of Migration and Single Motherhood in Upper Secondary Education in Mexico

    Science.gov (United States)

    Creighton, Mathew J.; Park, Hyunjoon; Teruel, Graciela M.

    2009-01-01

    We investigated the link between migration, family structure, and the risk of dropping out of upper secondary school in Mexico. Using two waves of the Mexican Family Life Survey, which includes 1,080 upper secondary students, we longitudinally modeled the role of family structure in the subsequent risk of dropping out, focusing on the role of…

  10. Fracturing controlled primary migration of hydrocarbon fluids during heating of organic-rich shales

    CERN Document Server

    Kobchenko, Maya; Renard, Francois; Dysthe, Dag Kristian; Malthe-Sorenssen, Anders; Mazzini, Adriano; Scheibert, Julien; Jamtveit, Bjorn; Meakin, Paul

    2011-01-01

    Time-resolved three-dimensional in situ high resolution synchrotron x-ray tomographic imaging was used to investigate the effects of slowly heating organic-rich Green River Shale from 60\\deg; to 400\\deg;C, in air without confinement, to better understand primary migration of hydrocarbon fluids in very low permeability source rock. Cracks nucleate in the interior of the sample at a temperature around 350\\deg;C. As the temperature increases, they grow and coalesce along lamination planes to form bigger cracks. This process is accompanied by a release of light hydrocarbons generated by decomposition of the initially immature organic matter, as determined by thermogravimetry and gas chromatography. These results provide the first 4D monitoring of an invasion percolation-like fracturing process in organic-rich shales. This process increases the permeability of the sample and provides pathways for fluid expulsion - an effect that might also be relevant for primary migration under natural conditions. We propose a 2D...

  11. Use of Invasion Percolation Models To Study the Secondary Migration of Oil and Related Problems

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, G.

    1997-12-31

    This thesis studies simulations of the slow displacement of a wetting fluid by a non-wetting fluid in porous media and in a single fracture. The simulations are based on the invasion percolation model. New modified versions of the model are presented that simulate migration, fragmentation and coalescence processes of the clusters of non-wetting fluid. The resulting displacement patterns are characterized by scaling laws. In particular, simulations of the secondary migration of oil through porous homogeneous rock are discussed. Fractured rocks are extreme cases of inhomogeneous porous media. Simulations of the slow displacement of a wetting fluid by a non-wetting fluid in a single fracture using the standard invasion model are presented. There is a discussion of a scenario in which a cluster of non-wetting fluid migrates through a porous medium that was saturated with a wetting fluid. The migration is driven by continuously driven buoyancy forces. Both experiments and simulations are described. The same scenario is also studied theoretically and by simulations using a simplified percolation model of fluid migration in one dimension. The migration model in two dimensions, with constant buoyancy forces, is also discussed. Simulations of fluid migration, such as the secondary migration of oil, in two- and three-dimensional media are examined, the media having multi-affine properties rather than being homogeneous. Slow immiscible displacement processes in single fractures are studied using fractal geometries to model single fractures. 167 refs., 123 figs.

  12. Analysis of carbon stable isotope to determine the origin and migration of gaseous hydrocarbon in the Brazilian sedimentary basins

    International Nuclear Information System (INIS)

    The carbon isotopic composition of natural gases to determine the origin and gaseous hydrocarbon migration of Brazilian sedimentar basins is analysed. The carbon isotopic ratio of methane from natural gases depends on the process of gas formation and stage of organic matter maturation. In the geochemical surface exploration the biogenic gases are differentiated from thermogenic gases, because the last one is isotopically heavier. As the isotopic composition of methane has not changed during migration, the migrated gases from deeper and more mature source rocks are identified by its relative 13C enrichment. The methane was separated from chromatography and and the isotopic analysis was done with mass spectrometer. (M.C.K.)

  13. Mobile and immobile migrated hydrocarbons in the Embla Field, North Sea

    Energy Technology Data Exchange (ETDEWEB)

    Bharati, Sunil

    1997-12-31

    This thesis deals with the geology of the Embla Field on the Norwegian Continental Shelf. This field has proven to be an excellent example to apply some of the recent ideas in reservoir geochemistry and has provided a sample set. Although the Embla field is in one of the most prolific regions of the Norwegian Continental Shelf, the Central Graben, its petroleum population is significantly different from neighbouring fields in more than one way. It is hoped that this work will provide a useful database for the planning of Embla`s further development. Migrated hydrocarbons are evaluated with respect to composition, maturity, intra-reservoir communication, compartmentalization and filling history of the field. The presence of immobile solid reservoir bitumen phase (paleo-oil) is mapped and explained and its origin and implications on overall reservoir quality are discussed. 206 refs., 118 figs., 34 tabs.

  14. A 4D synchrotron X-ray tomography study of the formation of hydrocarbon migration pathways in heated organic-rich shale

    OpenAIRE

    Panahi, Hamed; Kobchenko, Maya; Renard, Francois; Mazzini, Adriano; Scheibert, Julien; Dysthe, Dag Kristian; Jamtveit, Bjorn; Malthe-sørenssen, Anders; Meakin, Paul

    2013-01-01

    Recovery of oil from oil shales and the natural primary migration of hydrocarbons are closely related processes that have received renewed interests in recent years because of the ever tightening supply of conventional hydrocarbons and the growing production of hydrocarbons from low permeability tight rocks. Quantitative models for conversion of kerogen into oil and gas and the timing of hydrocarbon generation have been well documented. However, lack of consensus about the k...

  15. / Vanadium, nickel and porphyrins as tracers of secondary migration route of petroleum: Maracaibo Lake Basin, Venezuela

    Scientific Electronic Library Online (English)

    Marcos, Escobar; Angel, Da Silva; Vicmar, Azuaje; Iván, Esteves.

    2007-11-01

    Full Text Available Vanadio, níquel y porfirinas como trazadores de rutas de migración secundaria del petróleo: Cuenca del lago de Maracaibo, Venezuela [...] Abstract in english A model of secondary migration for the Marcelina (Paleocene) reservoir of the Alturitas oil field located in the Maracaibo Basin is proposed. For this purpose, diverse trace metals and biomarker-derived parameters were used, for a suite of 30 crude oil samples analyzed by SARA, GC-MS, ICP-OES and UV [...] -Visible techniques. Considering a unique geochemical type of crude oil in the reservoir [1-2], distributional changes along the reservoir area for selected parameters was studied. Ten trace metals were analyzed and splitted into two groups using multivariate statistic. The first group (Cd, Cu, Mo, Fe, P, Zn, Ca, Mg) does not display behaviors that can be associated to the secondary migration process but which rather they indicate a chalcophic association (Cd, Cu, Mo y Zn) or colloidal complexes with naphtenic acids (Ca, Mg, Fe). The behavior of the second groups, including total crude oil vanadium, nickel, porphyrins and resins plus asphaltenes concentrations, indicates that a natural chromatographic process has been affecting the crude oil composition, leading the proposition of a secondary migration route with a south-north oriented preferential migration axis. The analysis of different biomarkers did not throw clear results as far as the characterization of the process of migration and accumulation in the reservoir.

  16. A 4D synchrotron X-ray tomography study of the formation of hydrocarbon migration pathways in heated organic-rich shale

    CERN Document Server

    Panahi, Hamed; Renard, Francois; Mazzini, Adriano; Scheibert, Julien; Dysthe, Dag Kristian; Jamtveit, Bjorn; Malthe-Sørenssen, Anders; Meakin, Paul

    2014-01-01

    Recovery of oil from oil shales and the natural primary migration of hydrocarbons are closely related processes that have received renewed interests in recent years because of the ever tightening supply of conventional hydrocarbons and the growing production of hydrocarbons from low permeability tight rocks. Quantitative models for conversion of kerogen into oil and gas and the timing of hydrocarbon generation have been well documented. However, lack of consensus about the kinetics of hydrocarbon formation in source rocks, expulsion timing and how the resulting hydrocarbons escape from or are retained in the source rocks motivates further investigation. In particular, many mechanisms for the transport of hydrocarbons from the source rocks in which they are generated into adjacent rocks with higher permeabilities and smaller capillary entry pressures have been proposed, and a better understanding of this complex process (primary migration) is needed. To characterize these processes it is imperative to use the ...

  17. Fluid and hydrocarbon migration at active margins: A conceptual synthesis of results from the Barbados Ridge and Pacific northwest

    Energy Technology Data Exchange (ETDEWEB)

    Moore, J.C.; Orange, D.; Stiles, S.; Geddes, D. (Univ. of California, Santa Cruz (USA))

    1990-05-01

    At active convergent margins, offscraped sediments are imbricated at the deformation front and mature with attendant loss of fluids. Underthrust sediments slide beneath the accretionary prism at the velocity of the oceanic plate and continuously release fluids and/or hydrocarbons during descent. The continuous renewal of sediment by underthrusting beneath the accretionary prism suggests large cumulative fluid and hydrocarbon flux beneath any area of the prism. The asymmetrical loading of underthrust sediments by the tapered accretionary prism causes updip migration of fluids and hydrocarbons through stratigraphic conduits or the decollement zone at the base of the accretionary prism. Probable thermogenic hydrocarbons indicate long-distance lateral migration along these conduits from beneath the Barbados prism. Pore-water and temperature anomalies (Barbados) and biological indicators of fluid expulsion (Oregon) indicate that faults effectively capture fluid flow from the underthrust sequence (Barbados) and permeable sedimentary layers within the accretionary prisms (Oregon). Permeability measurements and hydrogeological modeling indicate that fault-capture of fluids requires permeabilities two to five orders of magnitude higher in the fault zones than in the source sediments. Complex deformation and diagenesis in accretionary prisms rapidly destroys the continuity of permeable stratigraphic conduits; faults become the principal migration conduits. The basinward growth of accretionary prisms require that they deform internally, commonly by out-of-sequence thrust; such thrusts may be migration conduits connecting underthrust or underplated source sediments to shallow reservoirs. Both in Barbados prism and the Pacific Northwest, out-of-sequence thrusts leak hydrocarbons and could feed reservoirs in overlying slightly deformed shelf and basinal sequences.

  18. La migration des hydrocarbures dans les bassins sédimentaires: aspects géologiques et géochimiques Migration of Hydrocarbons in Sedimentary Basins: Geological and Geochemical Aspects

    Directory of Open Access Journals (Sweden)

    Tissot B. P.

    2006-11-01

    Full Text Available La migration du pétrole vers les réservoirs et les pièges, et particulièrement son expulsion hors de la roche-mère où il s'est formé (migration primaire, est demeurée longtemps un des problèmes les plus mal connus de toute la géologie pétrolière. Le déplacement du pétrole et du gaz s'effectue en phase hydrocarbure séparée. L'eau, souvent considérée comme le véhicule du pétrole dans la migration, joue en fait un rôle négatif : il faut que la saturation en eau ait suffisamment diminué (par expulsion et que la saturation en hydrocarbures ait suffisamment augmenté (par génération à partir du kérogène pour que l'écoulement d'une phase hydrocarbure devienne possible. Le moteur de cette expulsion est le gradient de pression : l'élévation de la pression dans l'espace poreux des roches-mères résulte de trois causes (la charge sédimentaire, la genèse des hydrocarbures, et l'expansion thermique de l'eau. La microfissuration, qui survient quand la pression interne des fluides dépasse la résistance mécanique de la roche peut jouer un rôle important. Les observations dans les bassins sédimentaires de cas bien documentés sont encore trop rares. Il est, en particulier, difficile de calculer les réserves mobilisées à l'échelle d'un permis ou d'un bassin. La modélisation numérique de la migration, associée à celle de la genèse du pétrole et du gaz, offre des perspectives dans ce sens, mais elle demande encore des travaux complémentaires. Parmi les conséquences de la migration, on peut citer : la possibilité de corrélation huile/roche-mère, la teneur plus faible en produits lourds dans les réservoirs que dans les roches-mères et le rôle souvent joué par un déplacement où hydrocarbures liquides et gazeux forment une phase unique, qui migre en laissant progressivement derrière elle les fractions plus lourdes, par condensation rétrograde. Oil migration toward reservoirs and traps, and especially its expulsion from the source rock where it was formed (primary migration, has long remained one of the least well understood problems in all petroleum geology. The displacement of oil and gas occurs in a separate hydrocarbon phase. Water, which is often considered as the vehicle for oil during migration, effectively plays a negative role. Water saturation must have been sufficiently diminished (by expulsion and hydrocarbon saturation must be sufficiently increased (by generation from kerogen for the flow of a hydrocarbon phase to become possible. The driving force for this expulsion is the pressure gradient. A rise in pressure in the pore volume of source rocks results from three causes (the sedimentary load, the formation of hydrocarbons, and the thermal expansion of water. Microfracturing, which occurs when the internal pressure of fluids exceeds the mechanical strength of the rock, may play an important role. Observations of well documented cases in sedimentary basins are still too rare. In particular, it is difficult to compute the reserves mobilized on the scale of a permit or basin. The numerical modeling of migration combined with that of the formation of oil and gas opens up perspectives in this direction, but it still requires further work. Among the consequences of migration, mention can be made of the possibility of oil/source-rock correlation, the lower content of heavy products in reservoirs than in source rocks, and the role often played by a displacement in which liquid and gaseous hydrocarbons form a single phase that migrates while progressively leaving the heavier fractions behind it, by retrograde condensation.

  19. Use of Invasion Percolation Models To Study the Secondary Migration of Oil and Related Problems

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, G.

    1997-09-01

    In oil reservoir engineering, multi-phase displacement processes are important. This doctoral thesis describes simulations of the slow displacement of a wetting fluid by a non-wetting fluid in a complex, random porous medium and in a single fracture. The study is restricted to two-phase flow in the quasi-static limit in which viscous forces can be neglected. The secondary migration of oil takes place in this regime, however, the discussion is broader in scope. The thesis connects the problem of slow two-phase flow to percolation theory and discusses the mechanisms that control immiscible displacements. A new, modified version of the invasion percolation model is used to simulate an imbibition process in a porous medium and the migration of a cluster of non-wetting fluid through a porous medium saturated with a wetting fluid. The simulations include the secondary migration of oil through porous homogeneous rock. Fluid migration through heterogeneous porous media is simulated qualitatively. Slow displacement of a wetting fluid by a non-wetting fluid in a single rock fracture is simulated by using the standard invasion percolation model. Experiments and simulations are performed to study the fragmentation of invasion percolation-like structures of non-wetting fluid in a porous medium saturated with a wetting fluid. A scenario is studied in which a cluster of non-wettable fluid migrates through a porous medium that is saturated with a wetting fluid, the migration being driven by continuously increasing buoyancy forces. There is a simulation of the secondary migration of oil in both two- and three-dimensional media. 361 refs., 115 figs.

  20. Temperature dependence of secondary organic aerosol formation by photo-oxidation of hydrocarbons

    Science.gov (United States)

    Takekawa, Hideto; Minoura, Hiroaki; Yamazaki, Satoshi

    Photo-oxidation experiments on hydrocarbons were performed with a temperature-controlled smog chamber to study the temperature dependence of secondary organic aerosol (SOA) formation. A higher SOA yield was obtained at lower temperature and with a higher concentration of SOA generated. The relationship of SOA yield to temperature and SOA concentration is expressed by a gas/particle partitioning absorption model considered with temperature dependence. Under the condition of the same SOA concentration, the SOA yield at 283 K was approximately twice that at 303 K. It has been clarified experimentally that temperature is one of the most important factors in SOA formation. The experiments were performed not only with three aromatic hydrocarbons (toluene, m-xylene and 1,2,4-trimethylbenzene) and one biogenic alkene ( ?-pinene), but also with one alkane (n-undecane) on which few experiments for SOA formation have been performed. n-Undecane indicates a lower SOA yield than any other hydrocarbon investigated in this study.

  1. Contributions of Biogenic and Anthropogenic Hydrocarbons to Secondary Organic Aerosol during 2006 in Research Triangle Park, NC

    Science.gov (United States)

    A recently developed, organic tracer-based method was used to estimate the secondary contributions of biogenic and anthropogenic precursor hydrocarbons to ambient organic carbon concentrations in PM2.5 during 2006 in Research Triangle Park, North Carolina, USA. Forty-s...

  2. Secondary Organic Aerosol Produced from Non-Measured Hydrocarbons Downwind from the Oil Spill in the Gulf of Mexico

    Science.gov (United States)

    de Gouw, J. A.; Middlebrook, A. M.; Warneke, C.; Ahmadov, R.; Atlas, E. L.; Bahreini, R.; Blake, D. R.; Brock, C. A.; Brioude, J.; Fahey, D. W.; Fehsenfeld, F. C.; Gao, R.; Holloway, J. S.; Lueb, R.; McKeen, S. A.; Meagher, J. F.; Murphy, D. M.; Parrish, D. D.; Perring, A. E.; Pollack, I. B.; Ravishankara, A. R.; Robinson, A. L.; Ryerson, T. B.; Schwarz, J. P.; Spackman, J. R.; Srinivasan, A.; Watts, L.

    2010-12-01

    An extensively instrumented NOAA WP-3D research aircraft made airborne measurements of the gaseous and aerosol composition of air over the Deepwater Horizon (DWH) oil spill that occurred in April-July of 2010 in the Gulf of Mexico. A narrow plume of hydrocarbons was observed downwind from DWH that is attributed to the evaporation of fresh oil on the sea surface. A much wider plume of organic aerosol (OA) was attributed to secondary (SOA) formation from unmeasured, less volatile hydrocarbons that were emitted from a wider area around DWH. These observations provide compelling evidence for the importance of SOA formation from less volatile hydrocarbons, which has been proposed as a significant source of OA in the atmosphere.

  3. Influence of aerosol acidity on the formation of secondary organic aerosol from biogenic precursor hydrocarbons.

    Science.gov (United States)

    Offenberg, John H; Lewandowski, Michael; Edney, Edward O; Kleindienst, Tadeusz E; Jaoui, Mohammed

    2009-10-15

    Secondary organic carbon (SOC) concentrations in steady-state aerosol were measured in a series of alpha-pinene/NOx and one series of beta-caryophyllene/NOx irradiation experiments. The acidity of the inorganic seed aerosol was varied while the hydrocarbon and NOx concentrations were held constant in each series of experiments. Measurements were made for acidity levels and SOC concentrations much closer to ambient levels than had been previously achieved for alpha-pinene, while there are no previous measurements for SOC increases due to acidity for beta-caryophyllene. The observed enhancement in SOC concentration linearly increases with the measured hydrogen ion concentration in air for each system. For the conditions of these studies, SOC increased by 0.04% per nmol H+ m(-3) for alpha-pinene under two conditions where the organic carbon concentration differed by a factor of 5. For alpha-pinene, this level of response to acidic aerosol was a factor of 8 lower than was reported by Surratt et al. for similar series of experiments for SOC from the photooxidation of isoprene/NOx mixtures. By contrast, SOC from beta-caryophyllene showed an increase of 0.22% per nmol H+ m(-3), roughly two-thirds of the response in the isoprene system. Mass fractions for SOC particle-phase tracers for alpha-pinene decreased slightly with increasing aerosol acidity, although remaining within previously stated uncertainties. Below 200 nmol H+ m(-3), the mass fraction of beta-caryophyllenic acid, the only identified tracer for beta-caryophyllene SOC, was constant although beta-caryophyllenic acid showed a substantial decrease for acidities greater than 400 nmol H+ m(-3). PMID:19921888

  4. Geochemical assessment of hydrocarbon migration phenomena: Case studies from the south-western margin of the Dead Sea Basin

    Science.gov (United States)

    Sokol, Ella; Kozmenko, Olga; Smirnov, Sergey; Sokol, Ivan; Novikova, Sofya; Tomilenko, Anatoliy; Kokh, Svetlana; Ryazanova, Tatyana; Reutsky, Vadim; Bul'bak, Taras; Vapnik, Yevgeny; Deyak, Michail

    2014-10-01

    Calcite veins with fluid and solid bitumen inclusions have been discovered in the south-western shoulder of the Dead Sea rift within the Masada-Zohar block, where hydrocarbons exist in small commercial gas fields and non-commercial fields of heavy and light oils. The gas-liquid inclusions in calcite are dominated either by methane or CO2, and aqueous inclusions sometimes bear minor dissolved hydrocarbons. The enclosed flake-like solid bitumen matter is a residue of degraded oil, which may be interpreted as “dead carbon”. About 2/3 of this matter is soot-like amorphous carbon and 1/3 consists of n-C8sbnd C18 carboxylic acids and traces of n-alkanes, light dicarboxylic acids, and higher molecular weight (>C20) branched and/or cyclic carboxylic acids. Both bitumen and the host calcites show genetic relationship with mature Maastrichtian chalky source rocks (MCSRs) evident in isotopic compositions (?13C, ?34S, and ?18O) and in REE + Y patterns. The bitumen precursor may have been heavy sulfur-rich oil which was generated during the burial compaction of the MCSR strata within the subsided blocks of the Dead Sea graben. The ?18O and ?13C values and REE + Y signatures in calcites indicate mixing of deep buried fluids equilibrated with post-mature sediments and meteoric waters. The temperatures of fluid generation according to Mg-Li-geothermometer data range from 55 °? to 90 °? corresponding to the 2.5-4.0 km depths, and largely overlap with the oil window range (60-90 °?) in the Dead Sea rift (Hunt, 1996; Gvirtzman and Stanislavsky, 2000; Buryakovsky et al., 2005). The bitumen-rich vein calcites originated in the course of Late Cenozoic rifting and related deformation, when tectonic stress triggers damaged small hydrocarbon reservoirs in the area, produced pathways, and caused hydrocarbon-bearing fluids to rise to the subsurface; the fluids filled open fractures and crystallized to calcite with entrapped bitumen. The reported results are in good agreement with the existing views of maturation, migration, and accumulation of hydrocarbons, as well as basin fluid transport processes in the Dead Sea area.

  5. Unraveling the Timing of Fluid Migration and Trap Formation in the Brooks Range Foothills: A Key to Discovering Hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Catherine L. Hanks

    2008-12-31

    Naturally occurring fractures can play a key role in the evolution and producibility of a hydrocarbon accumulation. Understanding the evolution of fractures in the Brooks Range/Colville basin system of northern Alaska is critical to developing a better working model of the hydrocarbon potential of the region. This study addressed this problem by collecting detailed and regional data on fracture distribution and character, structural geometry, temperature, the timing of deformation along the Brooks Range rangefront and adjacent parts of the Colville basin, and the in situ stress distribution within the Colville basin. This new and existing data then were used to develop a model of how fractures evolved in northern Alaska, both spatially and temporally. The results of the study indicate that fractures formed episodically throughout the evolution of northern Alaska, due to a variety of mechanisms. Four distinct fracture sets were observed. The earliest fractures formed in deep parts of the Colville basin and in the underlying Ellesmerian sequence rocks as these rocks experienced compression associated with the growing Brooks Range fold-and-thrust belt. The orientation of these deep basin fractures was controlled by the maximum in situ horizontal stress in the basin at the time of their formation, which was perpendicular to the active Brooks Range thrust front. This orientation stayed consistently NS-striking for most of the early history of the Brooks Range and Colville basin, but changed to NW-striking with the development of the northeastern Brooks Range during the early Tertiary. Subsequent incorporation of these rocks into the fold-and-thrust belt resulted in overprinting of these deep basin fractures by fractures caused by thrusting and related folding. The youngest fractures developed as rocks were uplifted and exposed. While this general order of fracturing remains consistent across the Brooks Range and adjacent Colville basin, the absolute age at any one location varies. Fracturing started in the southwest deep in the stratigraphic section during the Late Jurassic and Early Cretaceous, moving northeastward and upsection as the Colville basin filled from the west. Active fracturing is occurring today in the northeastern parts of the Colville basin, north of the northeastern Brooks thrust front. Across northern Alaska, the early deep basin fractures were probably synchronous with hydrocarbon generation. Initially, these early fractures would have been good migration pathways, but would have been destroyed where subsequently overridden by the advancing Brooks Range fold-and-thrust belt. However, at these locations younger fracture sets related to folding and thrusting could have enhanced reservoir permeability and/or served as vertical migration pathways to overlying structural traps.

  6. Migrating Tundra Peregrine Falcons accumulate polycyclic aromatic hydrocarbons along Gulf of Mexico following Deepwater Horizon oil spill.

    Science.gov (United States)

    Seegar, William S; Yates, Michael A; Doney, Gregg E; Peter Jenny, J; Seegar, Tom C M; Perkins, Christopher; Giovanni, Matthew

    2015-07-01

    Monitoring internal crude oil exposure can assist the understanding of associated risks and impacts, as well as the effectiveness of restoration efforts. Under the auspices of a long-term monitoring program of Tundra Peregrine Falcons (Falco peregrinus tundrius) at Assateague (Maryland) and South Padre Islands (Texas), we measured the 16 parent (unsubstituted) polycyclic aromatic hydrocarbons (PAHs), priority pollutants identified by the United States Environmental Protection Agency and components of crude oil, in peripheral blood cells of migrating Peregrine Falcons from 2009 to 2011. The study was designed to assess the spatial and temporal trends of crude oil exposure associated with the 2010 Deepwater Horizon (DWH) oil spill which started 20 April 2010 and was capped on 15 July of that year. Basal PAH blood distributions were determined from pre-DWH oil spill (2009) and unaffected reference area sampling. This sentinel species, a predator of shorebirds and seabirds during migration, was potentially exposed to residual oil from the spill in the northern Gulf of Mexico. Results demonstrate an increased incidence (frequency of PAH detection and blood concentrations) of PAH contamination in 2010 fall migrants sampled along the Texas Gulf Coast, declining to near basal levels in 2011. Kaplan-Meier peak mean ?PAH blood concentration estimates varied with age (Juveniles-16.28 ± 1.25, Adults-5.41 ± 1.10 ng/g, wet weight) and PAHs detected, likely attributed to the discussed Tundra Peregrine natural history traits. Increased incidence of fluorene, pyrene and anthracene, with the presence of alkylated PAHs in peregrine blood suggests an additional crude oil source after DWH oil spill. The analyses of PAHs in Peregrine Falcon blood provide a convenient repeatable method, in conjunction with ongoing banding efforts, to monitoring crude oil contamination in this avian predator. PMID:25794559

  7. Viscoelastic Fracturing As a Migration and Expulsion Mechanism for Hydrocarbons in Shales: Analog Experiments

    Science.gov (United States)

    Van Damme, H.

    2014-12-01

    We report the results of simple laboratory experiments aimed at mimicking the generation, migration, and expulsion process of oil or gas from soft clayey sediments, triggered by thermal decomposition of organic matter. In previously published work, we showed that the injection of fluids into a soft sediment layer confined within a quasi-2D Hele-Shaw cell led to the transition from a viscous fingering invasion regime to a viscoelastic fracturing regime. The transition is controlled by the ratio of the characteristic times for the invasion process and for the structural relaxation in the sediment, respectively (Deborah number). Here we show that expulsion is a discontinuous quasi-periodic process, driven by the elastic energy stored in the embedding layers. We report also about two sets of experiments aimed at understanding the conditions in which fluid generation from multiple sources can generate a highly connected network of fractures for expulsion. In a first set of experiments, a Hele-Shaw cell with multiple injection points and multiple outlets was used. It is shown that, due to attractive elastic interactions between cracks, a network spontaneously forms as soon as invasion proceeds in the viscoelastic regime. On the contrary, no network of migration paths is forming in the viscous fingering regime, due to the effective repulsion of the fluid channels. In the second set of analog experiments, we used a thermostated mini-Hele-Shaw cell, the gap of which was filled with a strong clay mud in which microcrystals of reactive organic matter (azoisobutyronitrile, AIBN) are dispersed, or with a mud prepared with clay particles on which the organic matter was pre-impregnated. AIBN decomposes around 70°C, releasing nitrogen gas. It was again observed that, depending on the viscoelastic properties of the clay matrix, gas evolution occurs either by formation and coalescence of bubbles, or by formation of a percolating network of fractures. The length of the fracture network is initially linearly related to the Total (reactive) Organic Matter content. The expulsion process is remarkably effective in the fracturing regime (close to 100 percent), even at vey low TOC (below 0.5 percent). The relevance of these experiments for oil and gas migration in natural conditions will be discussed.

  8. An experimental investigation of geochromatography during secondary migration of petroleum performed under subsurface conditions with a real rock

    Directory of Open Access Journals (Sweden)

    Larter Steve

    2000-10-01

    Full Text Available An understanding of the size of petroleum secondary migration systems is vital for successful exploration for petroleum reserves. Geochemists have suggested that compositional fractionation of petroleum accompanying the migration process (geochromatography can potentially be used to infer distances petroleum may have travelled and the ratio of oil in the reservoir to that lost in the carrier. To date, this has been attempted by measuring concentrations and distributions of specific steranes, and aromatic oxygen and nitrogen compounds in reservoired oils which have been proposed to respond to migration rather than to source maturity or other effects. We report here an experiment involving oil migration through an initially water wet siltstone under realistic subsurface carrier bed or reservoir conditions (48 MPa, 70°C where source facies and maturity effects are eliminated. We show that geochromatography does indeed occur even for initially water-saturated rocks and that the migration fractionations observed for alkylcarbazoles, benzocarbazoles and alkylphenols are very similar to those seen in field data sets. In contrast, sterane based migration parameters show no compositional fractionation under these conditions.

  9. Use of a combined personal computer and Rock-Eval in an integrated petroleum evaluation work station to estimate volumes of hydrocarbons generated and migrated in sedimentary basins

    Energy Technology Data Exchange (ETDEWEB)

    Espitalie, J.; Lafargue, E.; Drouet, S. (Institut Francais du Petrole, Rueil-Malmaison)

    1989-09-01

    A petroleum evaluation work station consisting in a modified Rock-Eval apparatus connected to an IBM personal computer has been designed at Institut Francais du petrole to estimate the amount of hydrocarbon generated and migrated in sedimentary basins. The work-station is provided with specific software for Rock-Eval data analysis, quick determination of kinetic parameters (Optim model), and quantitative hydrocarbon generation (Matoil model). Along with the classical Rock-Eval parameters (S{sub 0}, S{sub 1}, S{sub 2}, TOC, and T{sub max}), new parameters concerning the source rocks, such as the transformation efficiency ratio (TER), the migration efficiency ration (MER), and the initial generation capacity (IGC), are defined. These new parameters combined with geological data give access to a rapid volumetric estimation (in 10{sup 6}MT/km{sup 2}) of hydrocarbon generation and migration in the studied area. These data can be displayed on different specific maps for rapid visualization. This work station has been successfully used in the Paris and Aquitaine basins, making possible a better assessment of their petroleum potential. The petroleum evaluation work station appears to be a very valuable tool that can be used in the different phases of exploration in a sedimentary basin.

  10. Evaluation des bassins par modélisation intégrée en deux dimensions des transferts techniques, de l'écoulement des fluides, de la genèse et de la migration des hydrocarbures Basin Evaluation by Integrated Two-Dimensional Modeling of Heat Transfer, Fluid Flow, Hydrocarbon Generation, and Migration

    Directory of Open Access Journals (Sweden)

    Chenet P. Y.

    2006-11-01

    Full Text Available Le modèle de bassin exposé dans cet article décrit les phénomènes physiques et chimiques qui contrôlent la formation d'accumulations commerciales, dans le cadre évolutif d'un bassin sédimentaire affecté par la subsidence : transfert de chaleur, compaction et écoulement de l'eau, génèse des hydrocarbures, migration diphasique de l'eau et des hydrocarbures. Le modèle tient compte des variations de conductivité et des phénomènes thermiques transitoires pour reconstituer les paléo-températures. Des validations quantitatives de la reconstitution des paléo-températures et du modèle cinétique de formation des hydrocarbures peuvent être obtenues par comparaison avec les températures actuelles et les données géochimiques. Les écoulements et les surpressions induits par la compaction sont décrits en couplant une loi de compaction avec la loi de Darcy, classique pour les écoulements de l'eau, en ajoutant un critère de fracturation hydraulique naturelle. Ceci permet de modéliser les pressions anormales dans des séquences deltaïques récentes (delta de la Mahakam, comme dans des bassins liés à des rifts anciens (mer du Nord. Une adaptation de la loi de Darcy aux écoulements diphasiques permet de reproduire la migration primaire et la migration secondaire. En particulier, le modèle permet d'étudier le rôle des pressions anormales et l'influence des failles sur la migration et le piégeage. Nos résultats confirment que les modèles de bassins peuvent contribuer à synthétiser les données géologiques, géophysiques et géochimiques dans un schéma cohérent. En précisant l'évaluation pétrolière, ces modèles constituent une des principales voies pour améliorer l'efficacité de l'exploration. The basin model discussed in this paper describes the physical and chemical phenomena that control the formation of commercial accumulations of hydrocarbons in the moving framework of a subsiding sedimentary basin : heat transfer, compaction and water flow, hydrocarbon generation, and two-phase migration of fluids. The model reproduces the influence of conductivity variations and of transient heat transfer on paleotemperatures. Quantitative verification of the paleotemperature reconstruction and of the kinetic model of hydrocarbon generation may be obtained from present temperatures and geochemical data. Compaction-driven flows and overpressures are described by coupling a compaction law with Darcy's law for water flow and a criterion for natural hydraulic fracturing. This formulation allows modeling of overpressures in young deltalic sequences (e. g. , the Mahakam delta, Indonesia as well as in old rift basins (e. g. , the North Sea. An adapted two-phase Darcy's law reproduces primary and secondary migration. In particular, the model helps investigate the role of overpressures and fault behavior on hydrocarbon migration and entrapment. Our results confirm that basin models contribute to the synthesis of geological, geophysical, and geochemical data consistently. By defining parameters for petroleum evaluations, these models increase exploration efficiency.

  11. Modern Processes of Hydrocarbon Migration and Re-Formation of Oil and Gas Fields (Based on the Results of Monitoring and Geochemical Studies)

    Science.gov (United States)

    Plotnikova, Irina; Salakhidinova, Gulmira; Nosova, Fidania; Pronin, Nikita; Ostroukhov, Sergey

    2015-04-01

    Special geochemical studies of oils allowed to allocate a movable migration component of oils in the industrial oil deposits. In the field the migration component of oils varies in different parts of the field. The largest percentage of the light migration component (gas condensate of the oil) was detected in the central part of the Kama-Kinel troughs system. Monitoring of the composition of water, oil and gas (condensate light oil component) in the sedimentary cover and ni crystalline basement led to the conclusion of modern migration of hydrocarbons in sedimentary cover. This proves the existence of the modern processes of formation and reformation of oil and gas fields. This presentation is dedicated to the problem of definition of geochemical criteria of selection of hydrocarbons deposit reformation zone in the sample wells of Minibaevskaya area of Romashkinskoye field. While carrying out this work we examined 11 samples of oil from the Upper Devonian Pashiysky horizon. Four oil samples were collected from wells reckoned among the "anomalous" zones that were marked out according to the results of geophysical, oil field and geological research. Geochemical studies of oils were conducted in the laboratory of geochemistry of the Kazan (Volga-region) Federal University. The wells where the signs of hydrocarbons influx from the deep zones of the crust were recorded are considered to be "anomalous". A number of scientists connect this fact to the hypothesis about periodic influx of deep hydrocarbons to the oil deposits of Romashkinskoye field. Other researchers believe that the source rocks of the adjacent valleys sedimentary cover generate gases when entering the main zone of gas formation, which then migrate up the section and passing through the previously formed deposits of oil, change and "lighten" their composition. Regardless of the point of view on the source of the hydrocarbons, the study of the process of deposits refilling with light hydrocarbons is an important fundamental task of exceptional practical importance. The reservoir water monitoring has been conducted in five wells that have penetrated the water-saturated, loosely aggregated zones of the South Tatarstan Arch's basement. The long-term testing resulted in the production of reservoir water from the basement. The sedimentary cover in these wells is blocked by the column, which prevents water cross-flowing from the sedimentary cover. The observations have shown that the levels, gas saturation, mineralisation, density, and composition of reservoir waters from the loosely aggregated zones of the basement change with time. The varying characteristics of the water include its component composition, redox potential, and amount of chlorine and some other components and trace elements. Compositional changes in gases of the loosely aggregated zones of the basement, variations in the gas saturation of reservoir waters and of their composition, the decreasing density of oil in the sedimentary cover, - all result from one cause. This cause is the movement of fluids (solutions and gases dissolved in them) through the loosely aggregated zones and faults of the Earth's crust and the sedimentary cover. The fluids mainly move vertically in an upward direction, although their migration through subhorizontal, loosely aggregated zones of the crystalline basement is also possible. Fluid migration still takes place in the Earth's crust of ancient platforms. This phenomenon indicates that some portions of the platforms - primarily, their margins - periodically resume tectonic activities. The fluid dynamic activity of the crust define the processes in the sedimentary cover. It affects the development of the sedimentary basin during the sedimentation period, and the formation of mineral deposits. The monitoring of the present-day movement of fluid systems in the loosely aggregated zones of the basement will permit the more detailed study of the present-day fluid regime in the upper portion of the Earth's crust and the sedimentary cover.

  12. Global modeling of secondary organic aerosol formation from aromatic hydrocarbons: high- vs low-yield pathways

    OpenAIRE

    Henze, D. K.; Seinfeld, J. H.; Ng, N. L.; Kroll, J. H.; -m Fu, T.; Jacob, D. J.; Heald, C. L.

    2007-01-01

    Formation of SOA from the aromatic species toluene, xylene, and, for the first time, benzene, is added to a global chemical transport model. A simple mechanism is presented that accounts for competition between low and high-yield pathways of SOA formation, wherein secondary gas-phase products react further with either nitric oxide (NO) or hydroperoxy radical (HO2) to yield semi- or non-volatile products, respectively. Aromatic species yield more SOA when they react with...

  13. A 4D Synchrotron X-Ray-Tomography Study of the Formation of Hydrocarbon- Migration Pathways in Heated Organic-Rich Shale

    Energy Technology Data Exchange (ETDEWEB)

    Hamed Panahi; Paul Meakin; Francois Renard; Maya Kobchenko; Julien Scheibert; Adriano Mazzini; Bjorn Jamtveit; Anders Malthe-Sorenssen; Dag Kristian Dysthe

    2013-04-01

    Recovery of oil from oil shales and the natural primary migration of hydrocarbons are closely related processes that have received renewed interest in recent years because of the ever tightening supply of conventional hydrocarbons and the growing production of hydrocarbons from low-permeability tight rocks. Quantitative models for conversion of kerogen into oil and gas and the timing of hydrocarbon generation have been well documented. However, lack of consensus about the kinetics of hydrocarbon formation in source rocks, expulsion timing, and how the resulting hydrocarbons escape from or are retained in the source rocks motivates further investigation. In particular, many mechanisms have been proposed for the transport of hydrocarbons from the rocks in which they are generated into adjacent rocks with higher permeabilities and smaller capillary entry pressures, and a better understanding of this complex process (primary migration) is needed. To characterize these processes, it is imperative to use the latest technological advances. In this study, it is shown how insights into hydrocarbon migration in source rocks can be obtained by using sequential high-resolution synchrotron X-ray tomography. Three-dimensional images of several immature "shale" samples were constructed at resolutions close to 5 um. This is sufficient to resolve the source-rock structure down to the grain level, but very-fine-grained silt particles, clay particles, and colloids cannot be resolved. Samples used in this investigation came from the R-8 unit in the upper part of the Green River shale, which is organic rich, varved, lacustrine marl formed in Eocene Lake Uinta, USA. One Green River shale sample was heated in situ up to 400 degrees C as X-ray-tomography images were recorded. The other samples were scanned before and after heating at 400 degrees C. During the heating phase, the organic matter was decomposed, and gas was released. Gas expulsion from the low-permeability shales was coupled with formation of microcracks. The main technical difficulty was numerical extraction of microcracks that have apertures in the 5- to 30-um range (with 5 um being the resolution limit) from a large 3D volume of X-ray attenuation data. The main goal of the work presented here is to develop a methodology to process these 3D data and image the cracks. This methodology is based on several levels of spatial filtering and automatic recognition of connected domains. Supportive petrographic and thermogravimetric data were an important complement to this study. An investigation of the strain field using 2D image correlation analyses was also performed. As one application of the 4D (space + time) microtomography and the developed workflow, we show that fluid generation was accompanied by crack formation. Under different conditions, in the subsurface, this might provide paths for primary migration.

  14. La migration des hydrocarbures dans les bassins sédimentaires: aspects géologiques et géochimiques Migration of Hydrocarbons in Sedimentary Basins: Geological and Geochemical Aspects

    OpenAIRE

    Tissot B. P.

    2006-01-01

    La migration du pétrole vers les réservoirs et les pièges, et particulièrement son expulsion hors de la roche-mère où il s'est formé (migration primaire), est demeurée longtemps un des problèmes les plus mal connus de toute la géologie pétrolière. Le déplacement du pétrole et du gaz s'effectue en phase hydrocarbure séparée. L'eau, souvent considérée comme le véhicule du pétrole dans la migration, joue en fait un rôle négatif : il faut que la saturation en eau ait suffisa...

  15. Abnormal organic-matter maturation in the Yinggehai Basin, South China Sea: Implications for hydrocarbon expulsion and fluid migration from overpressured systems

    Science.gov (United States)

    Hao, F.; Li, S.; Dong, W.; Hu, Z.; Huang, B.

    1998-01-01

    Three superimposed pressure systems are present in the Yinggehai Basin, South China Sea. A number of commercial, thermogenic gas accumulations have been found in an area in which shale diapirs occur. Because the reservoir intervals are shallow and very young, they must have filled with gas rapidly. The thick (up to 17 km) Tertiary and Quaternary sedimentary succession is dominated by shales, and is not disrupted by major faulting in the study area, a factor which seems to have had an important effect on both hydrocarbon generation and fluid migration. Organic-matter maturation in the deepest, most overpressured compartment has been significantly retarded as a result of the combined effects of excess pressure, the presence of large volumes of water, and the retention of generated hydrocarbons. This retardation is indicated by both kerogen-related parameters (vitrinite reflectance and Rock-Eval T(max)); and also by parameters based on the analysis of soluble organic matter (such as the C15+ hydrocarbon content, and the concentration of isoprenoid hydrocarbons relative to adjacent normal alkanes). In contrast to this, organic-matter maturation in shallow, normally-pressured strata in the diapiric area has been enhanced by hydrothermal fluid flow, which is clearly not topography-driven in origin. As a result, the hydrocarbon generation 'window' in the basin is considerably wider than could be expected from traditional geochemical modelling. These two unusual and contrasting anomalies in organic-matter maturation, together with other lines of evidence, suggest that there was a closed fluid system in the overpressured compartment until shale diapirs developed. The diapirs developed as a result of the intense overpressuring, and their growth was triggered by regional extensional stresses. They served as conduits through which fluids (both water and hydrocarbons) retained in the closed system could rapidly migrate. Fluid migration led to the modification of the thermal regime and the enhancement of organic maturation, as well as the accumulation of commercial volumes of gas in a relatively short time interval.Three superimposed pressure systems are present in the Yinggehai Basin, South China Sea. To date, a number of commercial, thermogenic gas accumulations have been found in an area in which shale diapirs occur. In fact, two unusual and contrasting anomalies in organic-matter maturation have been documented. These two anomalies, together with other lines of evidence, suggest that there was a closed fluid system in the overpressured compartment until shale diapirs developed. The diapirs developed as a result of intense overpowering, and their growth was triggered by regional extensional stresses. They served as conduits through which fluids retained in the closed system could rapidly migrate. Fluid migration led to the modification of the thermal regime and the enhancement of organic maturation, as well as the accumulation of commercial volumes of gas in a relatively short time interval.

  16. Global modeling of secondary organic aerosol formation from aromatic hydrocarbons: high- vs low-yield pathways

    Directory of Open Access Journals (Sweden)

    D. K. Henze

    2007-10-01

    Full Text Available Formation of SOA from the aromatic species toluene, xylene, and, for the first time, benzene, is added to a global chemical transport model. A simple mechanism is presented that accounts for competition between low and high-yield pathways of SOA formation, wherein secondary gas-phase products react further with either nitrogen oxide (NO or hydroperoxy radical (HO2 to yield semi- or non-volatile products, respectively. Aromatic species yield more SOA when they react with OH in regions where the [NO]/[HO2] ratios are lower. The SOA yield thus depends upon the distribution of aromatic emissions, with biomass burning emissions being in areas with lower [NO]/[HO2] ratios, and the reactivity of the aromatic with respect to OH, as a lower initial reactivity allows transport away from industrial source regions, where [NO]/[HO2] ratios are higher, to more remote regions, where this ratio is lower and, hence, the ultimate yield of SOA is higher. As a result, benzene is estimated to be the most important aromatic species with regards to formation of SOA, with a total production nearly equal that of toluene and xylene combined. In total, while only 39% percent of the aromatic species react via the low-NOx pathway, 72% of the aromatic SOA is formed via this mechanism. Predicted SOA concentrations from aromatics in the Eastern United States and Eastern Europe are actually largest during the summer, when the [NO]/[HO2] ratio is lower. Global production of SOA from aromatic sources is estimated at 3.5 Tg/yr, resulting in a global burden of 0.08 Tg, twice as large as previous estimates. The contribution of these largely anthropogenic sources to global SOA is still small relative to biogenic sources, which are estimated to comprise 90% of the global SOA burden, about half of which comes from isoprene. Compared to recent observations, it would appear there are additional pathways beyond those accounted for here for production of anthropogenic SOA. However, owing to differences in spatial distributions of sources and seasons of peak production, there are still regions in which aromatic SOA produced via the mechanisms identified here are predicted to contribute substantially to, and even dominate, the local SOA concentrations, such as outflow regions from North America and South East Asia during the wintertime, though total SOA concentrations there are small (~0.1 ?g/m³.

  17. Global modeling of secondary organic aerosol formation from aromatic hydrocarbons: high- vs. low-yield pathways

    Directory of Open Access Journals (Sweden)

    D. K. Henze

    2008-05-01

    Full Text Available Formation of SOA from the aromatic species toluene, xylene, and, for the first time, benzene, is added to a global chemical transport model. A simple mechanism is presented that accounts for competition between low and high-yield pathways of SOA formation, wherein secondary gas-phase products react further with either nitric oxide (NO or hydroperoxy radical (HO2 to yield semi- or non-volatile products, respectively. Aromatic species yield more SOA when they react with OH in regions where the [NO]/[HO2] ratios are lower. The SOA yield thus depends upon the distribution of aromatic emissions, with biomass burning emissions being in areas with lower [NO]/[HO2] ratios, and the reactivity of the aromatic with respect to OH, as a lower initial reactivity allows transport away from industrial source regions, where [NO]/[HO2] ratios are higher, to more remote regions, where this ratio is lower and, hence, the ultimate yield of SOA is higher. As a result, benzene is estimated to be the most important aromatic species with regards to global formation of SOA, with a total production nearly equal that of toluene and xylene combined. Global production of SOA from aromatic sources via the mechanisms identified here is estimated at 3.5 Tg/yr, resulting in a global burden of 0.08 Tg, twice as large as previous estimates. The contribution of these largely anthropogenic sources to global SOA is still small relative to biogenic sources, which are estimated to comprise 90% of the global SOA burden, about half of which comes from isoprene. Uncertainty in these estimates owing to factors ranging from the atmospheric relevance of chamber conditions to model deficiencies result in an estimated range of SOA production from aromatics of 2–12 Tg/yr. Though this uncertainty range affords a significant anthropogenic contribution to global SOA, it is evident from comparisons to recent observations that additional pathways for production of anthropogenic SOA still exist beyond those accounted for here. Nevertheless, owing to differences in spatial distributions of sources and seasons of peak production, regions exist in which aromatic SOA produced via the mechanisms identified here are predicted to contribute substantially to, and even dominate, the local SOA concentrations, such as outflow regions from North America and South East Asia during the wintertime, though total modeled SOA concentrations there are small (~0.1 ?g/m3.

  18. Migration to new ampoule types for the NPL secondary standard ionisation chambers

    International Nuclear Information System (INIS)

    As the pre-calibrated sample containers used for activity assay in the two NPL secondary standards ionisation chambers are being phased out, suitable replacements have been identified. Characterisation checks have been carried out on the new ISO ampoules and a long-term recalibration schedule has been devised. Around 40 calibration factors have been determined so far and comparison of ion chamber responses for the two ampoule types showed variations of up to 7% for low energy photon emitting radionuclides. - Highlights: • Present sample containers for NPL secondary standard ionisation chambers phased out. • Suitable replacement ampoules identified and characterisation checks performed. • Long-term calibration schedule devised and calibration factors determined. • Effect of new measurement matrix significant for low energy emitting radionuclides. • Recalibration enables maintenance of NPL's secondary standards of activity

  19. Secondary migration routes in the Brent sandstones of the Viking graben and east Shetland basin: Evidence from oil residues and subsurface pressure data

    Energy Technology Data Exchange (ETDEWEB)

    Miles, J.A. (Univ. of Reading (England))

    1990-11-01

    The Viking Graben of the North Sea contains a major deltaic reservoir - the Brent Group. Within the Brent Group, the Etive Formation, a coastal barrier sand, is both areally continuous and has excellent porosity and permeability. It is sandwiched between the fine-grained micaceous sandstones of the Rannoch Formation below and the impermeable mudstones of the Ness Formation above. Consequently, the Etive Formation has acted as the most important regional conduit for secondary migration of Upper Jurassic sourced oils. Oil migration through time has left a heavy residue in the uppermost part of the formation. These residues are aromatic-asphaltic, but otherwise resemble locally reservoired oils. Migration-sensitive biological marker ratios obtained from the residues change with distance from source. Secondary migration route mapping, based on the movement of oil by buoyancy in well-defined, isolated pressure compartments, integrated with timing of oil generation, indicates that the Ninian field could be sourced from two areas - Late Cretaceous migration from the southeast in the Viking Graben and Tertiary migration from the west and southwest - explaining some of the contrasting reservoir and oil characteristics of the Ninian and Lyell fields. 15 figs., 1 tab.

  20. Hydrologic and microbiological factors affecting persistence and migration of petroleum hydrocarbons spilled in a continuous-permafrost region

    Science.gov (United States)

    Braddock, J.F.; McCarthy, K.A.

    1996-01-01

    Fuel spills, totaling about 1300 m3, occurred between 1976 and 1978 adjacent to Imikpuk Lake, a drinking water source near Barrow, AK. Substantial contamination of soils and groundwater near the lake persists. We examined the magnitude and direction of groundwater flux and the microbial activity at this site to understand the persistence of contamination and its effect on the lake. We found that groundwater flux is small due to shallow permafrost, which restricts the cross-sectional area available for flow, and to the short annual thaw season (ca. 90 days). The small flux and limited depth also constrain contaminant transport and dispersion, resulting in persistent, shallow contamination. The numbers of hydrocarbon-oxidizing microorganisms and their laboratory mineralization potentials for benzene (at 10 ??C) were higher in samples from contaminated areas than in reference samples. Benzene mineralization potentials in groundwater samples were comparable to more temperate systems (0.1-0.5 mg of benzene mineralized L-1 day-1) and were stimulated by nutrient additions. Field measurements of dissolved oxygen, nitrate, ferrous iron, and sulfide in groundwater provided evidence that biodegradation of petroleum hydrocarbons is occurring in situ. Despite evidence of an active microbial population, microbial processes, like contaminant transport, are likely limited at this site by the short annual thaw season.

  1. Aryl hydrocarbon receptor activation in hematopoietic stem/progenitor cells alters cell function and pathway-specific gene modulation reflecting changes in cellular trafficking and migration.

    Science.gov (United States)

    Casado, Fanny L; Singh, Kameshwar P; Gasiewicz, Thomas A

    2011-10-01

    The aryl hydrocarbon receptor (AhR) is a transcription factor belonging to the Per-ARNT-Sim family of proteins. These proteins sense molecules and stimuli from the cellular/tissue environment and initiate signaling cascades to elicit appropriate cellular responses. Recent literature reports suggest an important function of AhR in hematopoietic stem cell (HSC) biology. However, the molecular mechanisms by which AhR signaling regulates HSC functions are unknown. In previous studies, we and others reported that treatment of mice with the AhR agonist 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) compromises the competitive reconstitution of bone marrow (BM) cells into irradiated host animals. Additional studies indicated a requirement for AhR in hematopoietic cells and not marrow microenvironment cells. In this study, we tested the hypothesis that TCDD-mediated phenotypic and functional changes of HSCs are a result of changes in gene expression that disrupt stem cell numbers and/or their migration. TCDD treatment to mice increased the numbers of phenotypically defined HSCs in BM. These cells showed compromised migration to the BM in vivo and to the chemokine CXCL12 in vitro, as well as increased expression of the leukemia-associated receptors CD184 (CXCR4) and CD44. Gene expression profiles at 6 and 12 h after exposure were consistent with the phenotypic and functional changes observed. The expressions of Scin, Nqo1, Flnb, Mmp8, Ilf9, and Slamf7 were consistently altered. TCDD also disrupted expression of other genes involved in hematological system development and function including Fos, JunB, Egr1, Ptgs2 (Cox2), and Cxcl2. These data support a molecular mechanism for an AhR ligand to disrupt the homeostatic cell signaling of HSCs that may promote altered HSC function. PMID:21791576

  2. A large-scale middle Miocene carbonate (?) mound structure in the Norwegian-Danish Basin: evidence for hydrocarbon migration?

    Science.gov (United States)

    Andresen, K. J.; Clausen, O. R.; Huuse, M.

    2007-12-01

    A mounded structure has been observed in the Norwegian-Danish Basin about 10 km east of the Coffee Soil Fault outside the Central Graben and almost directly on top of the mid-Miocene unconformity. The mounded structure has been mapped using 3D seismic data; it consists of two culminations arranged in a triangular area; one is 1500 m long, 800 m wide and 70 m high while the other is 800 m long, 400 m wide and 30 m high. The composite mound comprises a volume of some 29 mio m3 and is characterised by a high positive reflection amplitude at the top, differential compaction as compared to the surrounding sediments and velocity pull up in underlying reflections. These observations indicate a high velocity fill with higher acoustic impedance and less compaction than that of the surrounding sediments, and the interior of the mounded structure has thus been interpreted as a relatively hard, coarse grained or well cemented sediment. The observed mound is an isolated feature and there have been no reports on any similar structures in the surrounding area. Several possible morphological mound-shaped features have been considered such as igneous and clastic intrusions and extrusions, mud volcanoes, contourites, turbidites and carbonate mounds. The succession below the mound shows no vertical disturbance such as seismic chimneys or deformation of layers, and this seems to exclude an extrusive origin, which most likely would have had some influence on the sedimentary succession. Investigation of the base reflection in the surrounding area shows no sign of any erosional features such as submarine channels and this appears to exclude an origin as a turbidite or contourite since these features often are associated with some kind of erosion. Large present day seismic chimneys have been found in close proximity to the mound along with numerous elongated pockmarks in the Miocene succession right above the mound. These observations indicate that the study area is highly influenced by gas escape both at middle Miocene time and at present, which is in accordance to the general maturation of the hydrocarbons in the area (the Central Graben). This seems to be an important factor in interpretation of the mound. Following the observations, explanation of the precise location, uniqueness and isolated position of the mound is most easily accomplished when applying a carbonate related model. This model relates the paleogeographic position of the mound to the extensive gas escape in the area by implying that carbonate precipitation and build up in e.g. a bioherm was accomplished by bacterial methano-genesis facilitated by excess nutrition in the water column resulting from a high middle Miocene gas flux from the mature source rocks in the nearby Central Graben.

  3. Evidence for an unrecognized secondary anthropogenic source of organosulfates and sulfonates: gas-phase oxidation of polycyclic aromatic hydrocarbons in the presence of sulfate aerosol.

    Science.gov (United States)

    Riva, Matthieu; Tomaz, Sophie; Cui, Tianqu; Lin, Ying-Hsuan; Perraudin, Emilie; Gold, Avram; Stone, Elizabeth A; Villenave, Eric; Surratt, Jason D

    2015-06-01

    In the present study, formation of aromatic organosulfates (OSs) from the photo-oxidation of polycyclic aromatic hydrocarbons (PAHs) was investigated. Naphthalene (NAP) and 2-methylnaphthalene (2-MeNAP), two of the most abundant gas-phase PAHs and thought to represent "missing" sources of urban SOA, were photochemically oxidized in an outdoor smog chamber facility in the presence of nonacidified and acidified sulfate seed aerosol. Effects of seed aerosol composition, acidity and relative humidity on OS formation were examined. Chemical characterization of SOA extracts by ultra performance liquid chromatography coupled to electrospray ionization high-resolution quadrupole time-of-flight mass spectrometry revealed the formation of OSs and sulfonates from photo-oxidation in the presence of sulfate seed aerosol. Many of the organosulfur compounds identified in the smog chamber extracts were also measured in urban fine aerosol collected at Lahore, Pakistan, and Pasadena, USA, demonstrating that PAH photo-oxidation in the presence of sulfate aerosol is a hitherto unrecognized source of anthropogenic secondary organosulfur compounds, and providing new PAH SOA tracers. PMID:25879928

  4. Multispectral remote sensing mapping for hydrocarbon seepage-induced lithologic anomalies in the Kuqa foreland basin, south Tian Shan

    Science.gov (United States)

    Shi, Pilong; Fu, Bihong; Ninomiya, Yoshiki; Sun, Jimin; Li, Yang

    2012-03-01

    The mineralogy of oil and gas reservoirs can be altered through the effects of hydrocarbon seepage. Mapping this mineral alteration is thus a potential tool for hydrocarbon exploration. Hydrocarbons that escape from underground reservoirs can cause oxidation-reduction reactions in situ or along vertical migration pathways. They can also produce anomalies in surface sediments and soils. The surface changes can potentially be detected by various techniques, including geochemical, geophysical and remote sensing methods. In this study, satellite multi-spectral data combined with field spectrometry, geochemical and mineralogical information were evaluated for mapping areas of known hydrocarbon seepages from the Qiulitage thrust-and-fold belt in the Southern Tian Shan, northwest China. This study found that ASTER band ratios of 2/1 and 4/9 reveal mineral signatures related to alterations induced by hydrocarbon seepages such as bleached red bed and secondary carbonates, respectively in the Qiulitage thrust-and-fold belt. These overly known hydrocarbon seepages and thus provide a targeting tool for similar styles of hydrocarbon elsewhere. In addition, given that hydrocarbon seepages are also one of the non-negligible sources for emission of greenhouse gases, multispectral remote sensing system can thus potentially be used to map and monitor emission of greenhouse gas emissions from hydrocarbon accumulations.

  5. Migration of contaminants by gas phase transfer from carton board and corrugated board box secondary packaging into foods.

    Science.gov (United States)

    Jickells, S M; Poulin, J; Mountfort, K A; Fernàndez-Ocaña, M

    2005-08-01

    The gas phase transfer of substances from carton board (CB) and corrugated box board (CBB) through intervening layers to foods was studied. Substances covering a boiling point range of 252-425 degrees C and a range of polarities were incorporated into CB and CBB secondary packaging. Benzophenone was present in some CB materials. Where it was not already present in CB or CBB secondary packaging, it was deliberately incorporated for transfer studies. Transfer of substances was measured in nine foodstuff types stored in the secondary packaging at ambient and sub-ambient temperature. The foods were packaged in primary packaging materials that would be used in retail. Two food types were packed and stored in both single- and multipack formats. Foods were sampled at 0, 10, 30, 90 and 200 days and analysed by gas chromatography-mass spectrometry after high-performance size exclusion chromatography clean-up. Percentage transfer was between 0 and 100%. The overall trends were increased transfer of substances with increased storage time; a more rapid transfer of the more volatile substances compared with the less volatile ones and higher levels of transfer of the more volatile substances. No transfer of diheptyl phthalate (DHP) (bp 425 degrees C) as an incorporated substance was detected to any foods over the test period. The presence of an additional layer of packaging (multipack versus single pack) was shown to reduce transfer up to fourfold over 200 days and to increase the lag period for transfer. In terms of slowing transfer, metallized PP/PP laminate proved a more effective barrier than PP which was more effective than paper. It is postulated that there is a cut-off threshold for transfer at ambient and sub-ambient temperatures. Substances that are less volatile than the cut-off are anticipated not to transfer from secondary packaging to foods stored for up to 200 days, where the substances are present in the packaging at or below the levels tested in this study (up to 1 mg dm-2). In this study the volatility cut-off threshold lay between that of 2,2-dimethoxyphenylacetophenone (2,2-DMPAP) (an incorporated substance with bp 352 degrees C) and DHP. Ideally, the cut-off threshold should be expressed in terms of vapour pressure in the packaging material. In practical terms, it may be more appropriate to express as partition coefficient as this is simpler to determine experimentally. PMID:16147433

  6. Oil-bearing inclusions in vein quartz and kalcite and, bitumens in veins: Testament to multiple phases of hydrocarbon migration in the Barrandian basin (lower Palaeozoic), Czech Republic.

    Czech Academy of Sciences Publication Activity Database

    Suchý, V.; Dobeš, P.; Sýkorová, Ivana; Machovi?, Vladimír; Stejskal, M.; Kroužek, J.; Chudoba, J.; Mat?jovský, L.; Havelcová, Martina; Matysová, Petra

    2010-01-01

    Ro?. 27, ?. 1 (2010), s. 285-297. ISSN 0264-8172 R&D Projects: GA AV ?R(CZ) IAA3012703; GA AV ?R IAA300460804 Institutional research plan: CEZ:AV0Z30460519 Keywords : hydrocarbon * fluid inclusion * bitumen Subject RIV: DD - Geochemistry Impact factor: 2.130, year: 2010

  7. Polycyclic aromatic hydrocarbon (PAH)-mediated upregulation of hepatic microRNA-181 family promotes cancer cell migration by targeting MAPK phosphatase-5, regulating the activation of p38 MAPK

    Energy Technology Data Exchange (ETDEWEB)

    Song, Mi-Kyung [Center for Integrated Risk Research, Cellular and Molecular Toxicology Laboratory, Korea Institute of Science and Technology (KIST) (Korea, Republic of); School of Life Sciences and Biotechnology, Korea University, Anam-Dong, Seoungbuk-Gu, Seoul 136-701 (Korea, Republic of); Park, Yong-Keun [School of Life Sciences and Biotechnology, Korea University, Anam-Dong, Seoungbuk-Gu, Seoul 136-701 (Korea, Republic of); Ryu, Jae-Chun, E-mail: ryujc@kist.re.kr [Center for Integrated Risk Research, Cellular and Molecular Toxicology Laboratory, Korea Institute of Science and Technology (KIST) (Korea, Republic of)

    2013-11-15

    Growing evidence indicates that changes in microRNA (miRNA) expression in cancer induced by chemical carcinogens play an important role in cancer development and progression by regulating related genes. However, the mechanisms underlying miRNA involvement in hepatocarcinogenesis induced by polycyclic aromatic hydrocarbons (PAHs) remain unclear. Thus, the identification of aberrant miRNA expression during PAH-induced cancer cell migration will lead to a better understanding of the substantial role of miRNAs in cancer progression. In the present study, miRNA expression profiling showed significant upregulation of miR-181a, -181b, and -181d in human hepatocellular carcinoma cells (HepG2 line) exposed to benzo[a]anthracene (BA) and benzo[k]fluoranthene (BF). MAPK phosphatase-5 (MKP-5), a validated miR-181 target that deactivates MAPKs, was markedly suppressed while phosphorylation of p38 MAPK was increased after BA and BF exposure. The migration of HepG2 cells, observed using the scratch wound-healing assay, also increased in a dose-dependent manner. Depletion of miR-181 family members by miRNA inhibitors enhanced the expression of MKP-5 and suppressed the phosphorylation of p38 MAPK. Furthermore, the depletion of the miR-181 family inhibited cancer cell migration. Based on these results, we conclude that the miR-181 family plays a critical role in PAH-induced hepatocarcinogenesis by targeting MKP-5, resulting in the regulation of p38 MAPK activation. - Highlights: • We found significant upregulation of miR-181 family in HCC exposed to BA and BF. • We identified the MKP-5 as a putative target of miR-181 family. • MKP-5 was suppressed while p-P38 was increased after BA and BF exposure. • The migration of HepG2 cells increased in a dose-dependent manner.

  8. Polycyclic aromatic hydrocarbon (PAH)-mediated upregulation of hepatic microRNA-181 family promotes cancer cell migration by targeting MAPK phosphatase-5, regulating the activation of p38 MAPK

    International Nuclear Information System (INIS)

    Growing evidence indicates that changes in microRNA (miRNA) expression in cancer induced by chemical carcinogens play an important role in cancer development and progression by regulating related genes. However, the mechanisms underlying miRNA involvement in hepatocarcinogenesis induced by polycyclic aromatic hydrocarbons (PAHs) remain unclear. Thus, the identification of aberrant miRNA expression during PAH-induced cancer cell migration will lead to a better understanding of the substantial role of miRNAs in cancer progression. In the present study, miRNA expression profiling showed significant upregulation of miR-181a, -181b, and -181d in human hepatocellular carcinoma cells (HepG2 line) exposed to benzo[a]anthracene (BA) and benzo[k]fluoranthene (BF). MAPK phosphatase-5 (MKP-5), a validated miR-181 target that deactivates MAPKs, was markedly suppressed while phosphorylation of p38 MAPK was increased after BA and BF exposure. The migration of HepG2 cells, observed using the scratch wound-healing assay, also increased in a dose-dependent manner. Depletion of miR-181 family members by miRNA inhibitors enhanced the expression of MKP-5 and suppressed the phosphorylation of p38 MAPK. Furthermore, the depletion of the miR-181 family inhibited cancer cell migration. Based on these results, we conclude that the miR-181 family plays a critical role in PAH-induced hepatocarcinogenesis by targeting MKP-5, resulting in the regulation of p38 MAPK activation. - Highlights: • We found significant upregulation of miR-181 family in HCC exposed to BA and BF. • We identified the MKP-5 as a putative target of miR-181 family. • MKP-5 was suppressed while p-P38 was increased after BA and BF exposure. • The migration of HepG2 cells increased in a dose-dependent manner

  9. The presence of hydrocarbons in southeast Norway

    DEFF Research Database (Denmark)

    Hanken, Niels Martin; Hansen, Malene Dolberg

    Hydrocarbons, mostly found as solid pyrobitumen, are known from more than 30 localities in southeast Norway. They occur as inclusions in a wide range of "reservoir rocks" spanning from Permo-Carboniferous breccias to veins (vein quartz and calcite veins) in Precambrian granites, gneisses and amphibolites, and especially in primary and secondary pores in Cambrian, Ordovician and Silurian sedimentary rocks. In some places, vesicles in Carboniferous rhomb porphyry lava (RP1), gabbro and basalt (B1) are partly cemented with pyrobitumen, together with calcite, quartz and various accessory minerals. The pyrobitumen occurs as a jet-black, brittle, amorphous, non-fluorescent substance with a specific gravity of about 1.3 g/cm3 and a conchoidal fracture. Earlier analyses have shown great similarities with regard to the stable isotopes d13C in Alum Shale (Middle Cambrian to Lower Ordovician) and pyrobitumen, indicating that Alum Shale was the most important source rock. Petrographic investigations combined with stable isotope analyses (d13C and d18O) of the cement containing pyrobitumen indicate two phases of hydrocarbon migration. The first phase probably took place in Upper Silurian to Lower Devonian time, when the Alum Shale entered the oil window. These hydrocarbons are mostly found as pyrobitumen in primary voids and calcite cemented veins in Cambro-Silurian sedimentary deposits. The second phase is probably of Late Carboniferous/Permian age and was due to the increased heat flow during the formation of the Oslo Rift. These hydrocarbons are found in tectonically disturbed Precambrian basement rocks, veins in Lower Palaeozoic sedimentary rocks and as infills in amygdales in the two oldest extrusives (RP1 and B1) known from the Oslo Graben. The first migration phase was probably mainly directed towards higher stratigraphic levels. The second migration phase is suggested to have been much more complex including lateral, vertical and even downwards migration to basement. The occurrence of pyrobitumen in basement rocks outside the Oslo Graben, where no Palaeozoic rocks have been preserved, indicates that a thick cover of Palaeozoic sediments and lavas was originally also present outside the Oslo Rift.

  10. Aromatic hydrocarbons

    International Nuclear Information System (INIS)

    Papers dealing with radiolysis of aromatic hydrocarbons of different composition (from benzene to terphenyls and hydrocarbons with condensed rings) as well as their mixtures (with alkanes, alkenes, other aromatic hydrocarbons) are reviewed. High radiation stability of aromatic hydrocarbons in condensed phases associated with peculiarities of molecular structure of compounds is underlined. Mechanisms of radiolytic processes, vaues of product yields are considered

  11. Secondary Organic Aerosol Formation from the Photooxidation of Complex Hydrocarbon Mixtures: Composition, effect of SO2, and Relevance to Ambient Aerosol

    Science.gov (United States)

    Surratt, J. D.; Gao, S.; Knipping, E.; Edgerton, E.; Shahgoli, M.; Seinfeld, J. H.; Edney, E.; Kleindiesnt, T.; Lewandowski, M.; Offenberg, J.; Jaoui, M.

    2005-12-01

    Secondary organic aerosol (SOA) formation from single hydrocarbon precursors is commonly studied in smog chamber experiments to obtain SOA yield and organic composition data. However, very few complex air mixture experiments have been conducted to simulate possible conditions in ambient atmospheres. A six-phase experiment involving various combinations of alpha-pinene, toluene, isoprene, and SO2 were irradiated in the EPA's dynamic smog chamber at the National Exposure Research Laboratory in Raleigh, NC. Glass fiber filters and impactor plates were collected for each phase of the experiment to identify and quantify the nature of the SOA composition. The following suite of analytical techniques analyzed the resultant polar organic compounds and the high molecular weight species: liquid chromatography-electrospray ionization (ESI)-mass spectrometry, gas chromatography-mass spectrometry, ESI-ion trap mass spectrometry, matrix assisted laser desorption (MALDI)-time of flight mass spectrometry, and high-resolution mass spectrometry. When SO2 is present in the chamber, increases in the gravimetric aerosol mass concentration and in the abundance of polar organic compounds are observed, likely suggesting an acid catalysis effect stemming from the conversion of SO2 to H2SO4 that condenses onto aerosol formed. The addition of isoprene to a alpha-pinene/toluene mixture is found to lower the amount of aerosol produced and is also found to lower the abundance of organic compounds identified by the various analytical techniques. Lastly, many of the polar organic compounds identified and quantified here are also seen in the Southeastern Aerosol Research and Characterization (SEARCH) network during the summer of 2004. In particular, a sulfur and nitrogen containing organic species (MW = 295 gmol) is found to be the most abundant polar organic species identified in this field study (~28 % on average of the total identified organic mass). This species is also detected in the chamber experiment only when alpha-pinene and SO2 are both present in the chamber, suggesting that this abundant species is likely formed from monoterpene photooxidation. High-resolution mass spectrometry suggests the molecular formula for this species is C10H16NO7S.

  12. Influence of organic matter and clay minerals in migration of derivative compounds of hydrocarbons; Influencia da materia organica e argilominerais na migracao de compostos derivados de hidrocarbonetos

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, Denize Gloria Barcellos; Mendonca Filho, Joao Graciano de; Polivanov, Helena [Universidade Federal, Rio de Janeiro, RJ (Brazil). Inst. de Geociencias. Dept. de Geologia]. E-mail: denize@geologia.ufrj.br; graciano@geologia.ufrj.br; helena@acd.ufrj.br

    2003-07-01

    Soil samples from the Guanabara Bay in Duque de Caxias city (RJ) were submitted to mineralogical and organic geochemistry analyses. This proceeding was used mainly to determine a possible interaction of hydrocarbons contaminants with the organic matter and the clay minerals presents in this mangrove. The sampling was carried out using Direct Push techniques. Thus, the mainly clay minerals characterizes were: gibbsite, illite, caulinite and smectite. The compositional analysis of organic constituents showed a predominance of amorphous material (degraded cuticles), followed of wood material and sporomorphs constituents, suggesting that the biological degradation occurred in situ. (author)

  13. Benzo[b]naphthothiophenes and alkyl dibenzothiophenes: molecular tracers for oil migration distances

    Science.gov (United States)

    Li, Meijun; Wang, T.-G.; Shi, Shengbao; Liu, Keyu; Ellis, Geoffrey S.

    2014-01-01

    The secondary migration of petroleum is one of the most critical geological processes responsible for the accumulation of hydrocarbons in a sedimentary basin. Pyrrolic nitrogen compounds such as carbazoles and benzocarbazoles are thought to be practical molecular indicators for estimating relative migration distances of oil. In light oils or condensates, however, considerable analytical errors are usually caused by low concentrations of NSO-compounds. Here we show that polycyclic sulfur aromatic hydrocarbons such as dibenzothiophene, C1?C3 alkylated dibenzothiophenes and benzo[b]naphthothiophenes, which are present in relatively higher concentrations than the pyrrolic nitrogen compounds, exhibit changes in both absolute and relative concentrations that correlate with migration distances. The polycyclic sulfur aromatic hydrocarbons related parameters — benzo[b]naphtho[2,1-d]thiophene/{benzo[b]naphtho[2,1-d]thiophene + benzo[b]naphtho[1,2-d]thiophene} (abbreviated as [2,1]BNT/([2,1]BNT+[1,2]BNT) and the concentration of total dibenzothiophenes plus benzo[b]naphthothiophenes — are proposed by this paper to trace the oil migration distances.

  14. [(?(5)-C5Me5)Ru](+) fragments ligated to polyaromatic hydrocarbons: an experimental and computational approach to pathways for haptotropic migration.

    Science.gov (United States)

    Rioja, Matias; Hamon, Paul; Roisnel, Thierry; Sinbandhit, Sourisak; Fuentealba, Mauricio; Letelier, Karina; Saillard, Jean-Yves; Vega, Andrés; Hamon, Jean-René

    2015-01-01

    Ligand exchange reactions between [Cp*Ru(NCMe)3][PF6], where Cp* represents ?(5)-C5Me5, and the polycyclic aromatic hydrocarbons (PAHs) pyrene, acenaphthylene and fluoranthene afforded the known [Cp*Ru(?(6)-pyrene)][PF6] (1) and the new mixed sandwiches [Cp*Ru(?(6)-acenaphthylene)][PF6] (2) and [Cp*Ru(?(6)-fluoranthene)][PF6] (3), respectively, isolated in quantitative yields (94-100%). Complex 3 is formed as a mixture of two isomers: 3A as the major product where the [Cp*Ru(+)] moiety is coordinated to the naphthalene fragment of fluoranthene, and 3B with the coordination of the arenophile to the peripheral benzene ring, in a 90/10 spectroscopic ratio. The composition and identity of the complexes were deduced by elemental analysis, (1)H and (13)C multidimensional NMR spectroscopy, and mass spectrometry. Compounds 1A, 3A and 2A have been characterized using X-ray structural investigations. That showed that the [Cp*Ru(+)] unit is ?(6)-attached to one of the two naphthalene rings in each complex. Heating 1 and 3 at 90 °C in CD3NO2 solutions or heating 3 at 120 °C in the solid phase did not provide any evidence for thermally induced intramolecular inter-ring haptotropic rearrangements. These rearrangements were modelled by DFT calculations which indicated rather high activation energies. PMID:25382747

  15. Fault pattern and oil migration in Huang Hua depression, China

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Guojun (West Virginia Univ., Morgantown, WV (United States))

    1994-08-01

    Huang Hua depression is a back-arc intercratonic rift basin that developed on the north China platform in the Cenozoic. Controlled by the basement anisotropy, multidirectional fault sets on the plane are developed along the preexisting zone of weakness. According to the scale of tectonic elements controlled by faults, as well as its time of activity and depth, normal faults are divided into four grades in this basin. Seismic data and geological information have shown that 70% of the faults are listric faults. Flattening of the faults reflect tilting of fault block or detachment along the unconformity surfaces and ductile beds. Because of gravity creep and local extension main faults and secondary faults are united into a [open quotes]horse tail[close quotes] or [open quotes]Y[close quotes] patterns. Results of oil-source rock correlation and oil migration parameters all demonstrate that oil and gas migrate in or through faults (fracture zones), and form the [open quotes]step-like[close quotes] migration model. Faults in sandstone-shale sequences play the role of conduits for hydrocarbon, but faults in gypsum beds and thick undercompacted shales generally act as a top seal. To prevent oil migration through faults, reservoirs and ductile rocks with a high capillary displacement pressure must be juxtaposed. Whether faults are rejuvenated during hydrocarbon migration is not required for faults opening, but it is important to investigate the activity history of growth faults and the role of juxtaposed sediments in a sandstone-shale sequence in creating sealing and nonsealing faults.

  16. Paleo-oil and gas fields in the red sandstone of the North German Basin: Effects of hydrocarbon migration on storage quality development. Fluid flow, diagenesis and storage quality in the red sandstone strata of northern Germany; Palaeo-Oel- und -Gasfelder im Rotliegenden des Norddeutschen Beckens: Wirkung der KW-Migration auf die Speicherqualitaets-Entwicklung. Fluidfluss, Diagenese und Speicherqualitaet im Rotliegend Norddeutschlands

    Energy Technology Data Exchange (ETDEWEB)

    Solms, M. [SGC, Lehrte (Germany); Gaupp, R. [Jena Univ. (Germany); Littke, R.; Schwarzer, D. [RWTH Aachen (Germany); Schubarth-Engelschall, J.; Trappe, H. [TEEC, Isernhagen (Germany); Krawczyk, C.; Tanner, D.; Oncken, O. [GFZ, Potsdam (Germany)

    2003-07-01

    This sub-project was aimed at improving the geological concept of the development of storage quality, at the development of a model for monitoring and reconstruction of the structural development and restructuring of reservoirs, and at obtaining information on hydrocarbon origins, migration pathways and filling chronology. Drill core data were combined with 3D seismic data in order to obtain a deeper understanding of the processes involved. [German] Im Rahmen des DGMK-Forschungsprogrammes ''Tight Gas Reservoirs'' (Projekt 593-8) wurden von der Arbeitsgruppe Sedimentologie 43 Bohrungen aus dem Rotliegend Nordwestdeutschlands untersucht. Die vorgestellten Ergebnisse schliessen sich an den Vortrag ''Einfluss von Fazies und Diagenese auf die Speicher-Qualitaets-Entwicklung von Rotliegendsandsteinen NW Deutschlands'' (SOLMS et al., DGMK-Fruehjahrstagung 2002). Ziel dieses Teilprojektes ist die Verbesserung des geologischen Konzeptes zur Entwicklung der Speicherqualitaet, die Entwicklung eines Modells zur Erfassung und Rekonstruktion der strukturellen Entwicklung und Restrukturierung von Lagerstaetten sowie die Klaerung von KW-Herkunftsgebieten, Migrationswegen und Fuellungschronologien. Durch die Verknuepfung der Kerndaten mit 3D seismischen Daten soll eine verbesserte Einschaetzung der Speicherqualitaeten aus dem 3D seismischen Abbild erreicht werden. (orig.)

  17. Aromatic hydrocarbons

    International Nuclear Information System (INIS)

    The radiolysis of aromatic hydrocarbons, product yields and possible mechanisms of radiation chemical reactions are discussed in detail. Individual compounds are considered separately and the radiolysis of mixtures is also investigated. The reasons for the radiation stability of aromatics in condensed phases are presented and the intramolecular reactions of alkylaromatics and aromatic mixtures are compared. (Auth./C.F.)

  18. Molecular and carbon isotope compositions of hydrocarbon gas in Neogene sedimentary rocks in Horonobe area, Northern Hokkaido, Japan

    International Nuclear Information System (INIS)

    We conducted headspace gas analyses using cores from two 520 m boreholes to evaluate the gas permeability of Neogene sedimentary rocks in Horonobe, Hokkaido, Japan. Analytical data suggest that most hydrocarbon gases are microbial methane. Further analyses of these data indicated that the low concentration and heavy carbon isotope composition of methane could be explained by carbon isotopic fractionation during migration near fractures. The high residual volume of microbial methane observed in the study area suggests that the sedimentary layers have low gas permeability, and are affected less by secondary post-generation processes. The headspace gas analysis is an effective approach for detecting sedimentary layers having a high confinement capability. (author)

  19. Fluid Inclusions Usage for Assessing Oil Migration in Duhok, North Iraq

    Directory of Open Access Journals (Sweden)

    Salih Muhammad Awadh

    2010-11-01

    Full Text Available Studies of primary and secondary fluid inclusions were done on epigenetic barite samples collected from carbonates of Lower part of Sarmord Formation (Lower Cretaceous and Aqra-Bekhme Formations (Upper Cretaceous in Duhok, north Iraq. Lead isotopes composition in galena which associated barite that contained fluid inclusions helped the identification two events of fluid inclusions. These fluid inclusions contain brine water and hydrocarbons. Primary and secondary fluid inclusions in barite as well as lead isotopes composition in galena helped the interpretation of oil migration history and the pathway of oil migration. Ages of galena are syngronous with the events of oil and water trapping as inclusions within barite, and hence the interpreted galena generation could be assigned to the fluid inclusions age. Accordingly, the events are two phases of early and late generations that correspond to 120 m.y. and 30 m.y. respectively. Correlation with 10 PetroMod basin modeling of the generated oil from the Jurassic and Lower Cretaceous Formations fitted with the event of early galena generation, whereas the oil migration started before 70 m.y. and continued to 30 m.y. ago. Palynomorphs study confirmed that the oil in source rocks is similar with the migrated oil.

  20. Migration dynamics

    OpenAIRE

    Vergalli, Sergio; Moretto, Michele

    2002-01-01

    This paper tries to explain why most migration flows show some observable jumps in their processes, a phenomenon that seems to be sympathetic with the characteristic of irreversibility of migration. We present a real option model where the choice to migrate depends on both the differential wage between the host country and the country of origin, and on the probability of being fully integrated into the host country. The theoretical results show that the optimal migration decision of a single ...

  1. Experimental simulation of hydrocarbon expulsion

    Energy Technology Data Exchange (ETDEWEB)

    Lafargue, E.; Espitalie, J. (Institut Francais du Petrole (IFP), 92 - Rueil-Malmaison (France)); Jacobsen, T.; Eggen, S. (STATOIL, Stavangar (Norway))

    1990-01-01

    An experimental device to study hydrocarbon expulsion out of source-rocks has been designed. The results indicate fractionation effects due to hydrocarbon primary migration that are in good accordance with observations on real cases reported in the literature. In particular, saturated hydrocarbons are expelled more effectively than aromatics and n-alkanes seem to be removed preferentially to isoprenoids. The simulation has been conducted in a temperature-controlled high pressure cell (temperature range, 25-350[sup o]C; pressure range, 0-5000 bar) on 4 cm long source-rock cores (dia 4 cm) with an adjoining reservoir 1 cm thick (dia 4 cm). In this apparatus, the source-rock sample is submitted to confining pressure and a pressure gradient is produced between the source-rock and the reservoir. Two types of experiments were carried out: expulsion experiments at moderate temperatures on immature source-rocks where hydrocarbons are artificially generated at high temperatures (up to 350[sup o]C) prior to expulsion at lower temperatures. (author)

  2. Paleo-oil and gas fields in the red sandstone of the North German Basin: Effects of hydrocarbon migration on storage quality development. Structural analysis (3D) and basin modelling (3D) of tight gas areas at the southern border of the red sandstone gas play; Palaeo-Oel- und -Gasfelder im Rotliegenden des Norddeutschen Beckens: Wirkung der KW-Migration auf die Speicherqualitaets-Entwicklung. Strukturelle Analyse (3D) und Beckenmodellierung (2D) im Bereich von Tight Gas Arealen am Suedrand des Rotliegenden Gas Plays

    Energy Technology Data Exchange (ETDEWEB)

    Schwarzer, D.; Littke, R. [RWTH Aachen, Lehrstuhl fuer Erdoel und Kohle (Germany); Tanner, D.; Krawczyk, C.; Oncken, O. [GFZ, Potsdam (Germany); Solms, M. [Jena Univ. (Germany)]|[SGC, Lehrte (Germany); Gaupp, R. [Jena Univ. (Germany); Schubarth-Engelschall, J.; Trappe, H. [TEEC, Isernhagen (Germany)

    2003-07-01

    The GFZ Potsdam and RWTH Aachen universities analyzed the structural development of the area in question and attempted an integration of the data in a basin simulation model. Key issues were (i) tectonic developments in the red sandstone, which are reconstructed by means of fault analysis and re-deformation; (ii) mesozoic and kenozoic developments with their extensive salt migration, which are largely independent of the existing presalinary structures; (iii) temperature and maturity, hydrocarbon formation and migration; (iv) effects of faults on migration pathways and reservoir development. [German] Im Rahmen des DGMK-Forschungsvorhabens ''Tight Gas Reservoirs'' beschaeftigen sich innerhalb des Teilprojektes 593-8 ''Palaeo-Oel- und -Gasfelder im Rotliegenden des Norddeutschen Beckens - Wirkung der KW-Migration auf die Speicherqualitaetsentwicklung'' die Arbeitsgruppen am GFZ Potsdam und an der RWTH Aachen mit der Analyse der strukturellen Entwicklung des Untersuchungsgebietes und der Integration dieser Daten in ein Beckensimulationsmodell. Schwerpunkte der Untersuchungen sind dabei (i) die tektonische Entwicklung im Rotliegenden, die mittels Stoerungsanalyse und Rueckverformung rekonstruiert wird, (ii) die mesozoische und kaenozoische Entwicklung, die von umfangreichen Salzbewegungen gepraegt ist und weitestgehend von den bestehenden Strukturen im Praesalinar entkoppelt ist, (iii) die Temperatur. und Reifeentwicklung, KW-Bildung und -Migration sowie (iv) der Einfluss der Stoerungen auf Migrationspfade und die Bildung von Lagerstaetten. (orig.)

  3. Solvent migration in a paraffin deposit

    Energy Technology Data Exchange (ETDEWEB)

    Cordoba, A.J.; Schall, C.A. [Genentech, South San Francisco, CA (United States)

    2001-07-06

    Temporal changes in solvent content of deposits formed on a tube wall were measured for a binary system of hydrocarbons, nonadecylcylohexane and octane. Solvent content in the deposited nonadecylcyclohexane decreased over time, consistent with the phenomena of migration of included solvent in a temperature gradient. An understanding of inclusion migration in deposits can provide a framework for modeling the aging of paraffin deposits in crude oil pipelines. 14 refs., 5 figs.

  4. Permian-Triassic maturation and multistage migration of hydrocarbons in the Assistência Formation (Irati Subgroup), Paraná Basin, Brazil: implications for the exploration model / Maturação permotriássica e os vários estágios de migração de hidrocarbonetos na Formação Assistência (Subgrupo Irati), Bacia do Paraná: implicações para os modelos exploratórios

    Scientific Electronic Library Online (English)

    António, Mateus; Claudio, Riccomini; Ezequiel J. E. C. B., Ferreira; Colombo C. G., Tassinari.

    2014-09-01

    Full Text Available Novas linhas de evidências geológicas sugerem fortemente que o principal período de maturação de hidrocarbonetos na Formação Assistência teria ocorrido no Permotriássico, estimulado por um gradiente geotérmico elevado que também sustentou várias manifestações de atividade hidrotermal. Três fases pri [...] ncipais de migração de fluidos e hidrocarbonetos também podem ser inferidas a partir de observações em multiescala: fluxo confinado no final do Permiano ao Triássico, dependente do acúmulo local de pressões de fluidos; fluxo heterogêneo no Cretáceo Inferior, desencadeado por um gradiente de temperatura rejuvenescido, assistido pelas condições de permeabilidade antes desenvolvidas; e um fluxo tardio, possivelmente impulsionado por gradientes de pressão locais, posteriormente ao esfriamento dos diques e soleiras de diabásio. A maturação precoce e a existência de vários estágios de migração de hidrocarbonetos apresentam implicações significativas na concepção de modelos exploratórios a serem aplicados na Bacia do Paraná. Abstract in english New lines of geological evidence strongly suggest that the main period of hydrocarbon maturation within Assistência Formation should be Permian-Triassic, stimulated by a high geothermal gradient that also sustained various manifestations of hydrothermal activity. Three main stages of fluid/hydrocarb [...] on migration can also be inferred on the basis of multiscale observations: confined flow in late Permian to Triassic times, depending on the local build-up of fluid pressures; heterogeneous flow in Lower Cretaceous, triggered by a rejuvenated temperature gradient assisted by the early developed permeability conditions; and a late flow possibly driven by local pressure gradients, after complete cooling of dolerite dykes/sills. The early maturation and multistage migration of hydrocarbons have significant consequences in the design of exploration models to be applied in Paraná Basin.

  5. Sediment gases as indicators of subsurface hydrocarbon generation and entrapment - examining the record both in laboratory and field studies

    OpenAIRE

    Abrams, Michael Allan

    2008-01-01

    Surface geochemistry, the measurement of near-surface hydrocarbons, has been used by the petroleum industry for more than 80 years to explore for subsurface petroleum deposits. The fact that hydrocarbons generated deep in the sedimentary section from thermally mature organic rich rocks can migrate to the near-surface in measurable concentrations is well documented but the methods currently used by industry to extract and measure these near-surface migrated hydrocarbons have ...

  6. Migration chemistry

    International Nuclear Information System (INIS)

    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 KD 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.)

  7. Monarch Migration.

    Science.gov (United States)

    Williamson, Brad; Taylor, Orley

    1996-01-01

    Describes the Monarch Watch program that tracks the migration of the monarch butterfly. Presents activities that introduce students to research and international collaboration between students and researchers. Familiarizes students with monarchs, stimulates their interest, and helps them generate questions that can lead to good research projects.…

  8. Identification and numerical modelling of hydrocarbon leakage in the Lower Congo Basin: Implications on the genesis of km-wide seafloor mounded structures

    Science.gov (United States)

    Anka, Zahie; Ondrak, Robert; Kowitz, Astrid; Schødt, Niels

    2013-09-01

    We present a combined approach of interpretation of 2D seismic-reflection data and numerical modelling of hydrocarbon generation and migration across the southern slope of the Lower Congo Basin, in order to investigate the factors controlling timing and distribution of hydrocarbon leakage in this area. We identified three main families of past and present-day leakage features: (1) Mid-Upper Miocene seismic chimneys concentrated basinwards and ending up on buried pockmarks, (2) Plio-Pleistocene chimneys, rather clustered to the east of the study area and ending up in seafloor pockmarks, and (3) fewer scattered chimneys identified within the Miocene sequences ending up in shallow enhanced reflectors ("Flat spots"). Stratigraphic and structural elements seem to control the distribution of these features. At least two major events of leakage occurred during the Middle-Late Miocene and intermittently during the Pliocene-Present. External factors as sediment supply are associated to the Miocene leakage event, whilst internal structural elements probably triggered the Pliocene to present-day leakage. A major seabed morphological feature, represented by a margin-paralleled belt of more than 1-km-wide mounds, was identified above growth faults to the east of the study area. Data-constrained 2D HC generation and migration modelling suggests a genetic link between these structures and vertical migration/leakage of thermogenic methane sourced from either currently mature Oligo-Miocene source rocks or secondary cracking and further expulsion from over-mature Upper-Cretaceous source rocks. Hence, the mounds are likely to represent a lineation of methane-derived carbonate build-ups. Despite the natural limitations of a 2D migration model, when combined and calibrated with observations from seismic data, it can be used as a valid tool to assess petroleum migration routes in sedimentary basins. To the best of our knowledge, this is the first integrated approach combining both seismic observations and numerical modelling carried out in the Angola basin.

  9. Characterization of Collective Cell Migration Dynamics

    Science.gov (United States)

    Lee, Rachel; Yue, Haicen; Rappel, Wouter-Jan; Losert, Wolfgang

    2015-03-01

    During cancer progression, tumor cells invade the surrounding tissue and migrate throughout the body, forming clinically dangerous secondary tumors. This metastatic process begins when cells leave the primary tumor, either as individual cells or collectively migrating groups. Here we present data on the migration dynamics of epithelial sheets composed of many cells. Using quantitative image analysis techniques, we are able to extract motion information from time-lapse images of cell lines with varying malignancy. Adapting metrics originally used to study fluid flows we are able to characterize the migration dynamics of these cell lines. By describing the migration dynamics in great detail, we are able to make a clear comparison of our results to a simulation of collective cell migration. Specifically, we explore whether leader cells are required to describe our expanding sheets of cells and whether the answer depends on individual cell activity.

  10. Evaluation des bassins par modélisation intégrée en deux dimensions des transferts techniques, de l'écoulement des fluides, de la genèse et de la migration des hydrocarbures Basin Evaluation by Integrated Two-Dimensional Modeling of Heat Transfer, Fluid Flow, Hydrocarbon Generation, and Migration

    OpenAIRE

    Chenet P. Y.; Bessis F.; Ungerer P.; Burrus J.; Doligez B.

    2006-01-01

    Le modèle de bassin exposé dans cet article décrit les phénomènes physiques et chimiques qui contrôlent la formation d'accumulations commerciales, dans le cadre évolutif d'un bassin sédimentaire affecté par la subsidence : transfert de chaleur, compaction et écoulement de l'eau, génèse des hydrocarbures, migration diphasique de l'eau et des hydrocarbures. Le modèle tient compte des variations de conductivité et des phénomènes thermiques transitoires pour reconstituer les palé...

  11. Hydrocarbon Reserves: Abundance or Scarcity

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    IFP and the OAPEC jointly organize a regular international seminar dealing with world oil-related problems appearing in the news. For the first time, this seminar has been opened to oil and gas company specialists, service companies, research centers and independents. This year's theme concerns oil and gas reserves: are they abundant or are we headed towards the shortages announced by some experts? This theme is especially topical in that: oil and gas currently meet two thirds of world energy needs and almost completely dominate the transport sector; the reserves declared by the OAPEC countries account for nearly half of world reserves; the price of a barrel of oil went through the roof in 2004; world energy demand is growing fast and alternative sources of energy are far from ready to take over from oil and gas in the next few decades. Since the reserves correspond to the volume it is technically and economically viable to produce, the seminar has, of course, dealt with the technical and economic questions that arise in connection with exploration and production, but it has also considered changes in the geopolitical context. Presentations by the leading companies of the OAPEC countries and by the IFP group were completed by presentation from the International Energy Agency (IEA), the United States Geological Survey (USGS), the IHS Energy Group, Total and Gaz de France. This document gathers the transparencies of the following presentations: Hydrocarbon reserves in OAPEC members countries: current and future (M. Al-Lababidi); Non OAPEC liquid reserves and production forecasts (Y. Mathieu); World oil and gas resources and production outlook (K. Chew); Global investments in the upstream (F. Birol); Total's policy in the oil and gas sector (C. de Margerie); Gaz de France's policy in the oil and gas sector (J. Abiteboul); NOC/IOC's opportunities in OPEC countries (I. Sandrea); Relationships between companies, countries and investors: How they may impact on the growth of reserves and resources (H. Le Leuch); Additional reserves: the role of new technologies - A global perspective on EORIOR (G. Fries); - Updating reservoir models with dynamic data and uncertainty quantification: an integrated approach (F. Roggero); Seismic technology for the OAPEC countries (P. Canal); Exploration knowledge and technologies: impact of progress - Statistical results (N. Alazard); Stratigraphic modelling as a key to find new potentialities in exploration (D. Granjeon); Modelling hydrocarbon migration as a tool for reserve estimation (J-L. Rudkiewicz); The contribution of surface and near surface geology to hydrocarbon discoveries (S.M. Kumati); Contribution of the exploration activity in renewing reserves - The case of Algeria (R. Lounissi); Egypt's petroleum hydrocarbon potential (H. Hataba); Future of hydrocarbon reserves in Syria (T. Hemsh); Natural gas, the fuel of choice for decades to com (M.F. Chabrelie); The role and importance of Arab natural gas in world market (M. Al-Lababidi); LNG and GTL: two pathways for natural gas utilization (C. Cameron); Yet to find hydrocarbon potential (S. Al Menhali); Libyan context of hydrocarbon reserves: abundance or scarcity? (M. Elazi)

  12. Hydrocarbon Reserves: Abundance or Scarcity

    International Nuclear Information System (INIS)

    IFP and the OAPEC jointly organize a regular international seminar dealing with world oil-related problems appearing in the news. For the first time, this seminar has been opened to oil and gas company specialists, service companies, research centers and independents. This year's theme concerns oil and gas reserves: are they abundant or are we headed towards the shortages announced by some experts? This theme is especially topical in that: oil and gas currently meet two thirds of world energy needs and almost completely dominate the transport sector; the reserves declared by the OAPEC countries account for nearly half of world reserves; the price of a barrel of oil went through the roof in 2004; world energy demand is growing fast and alternative sources of energy are far from ready to take over from oil and gas in the next few decades. Since the reserves correspond to the volume it is technically and economically viable to produce, the seminar has, of course, dealt with the technical and economic questions that arise in connection with exploration and production, but it has also considered changes in the geopolitical context. Presentations by the leading companies of the OAPEC countries and by the IFP group were completed by presentation from the International Energy Agency (IEA), the United States Geological Survey (USGS), the IHS Energy Group, Total and Gaz de France. This document gathers the transparencies of the following presentations: Hydrocarbon reserves in OAPEC members countries: current and future (M. Al-Lababidi); Non OAPEC liquid reserves and production forecasts (Y. Mathieu); World oil and gas resources and production outlook (K. Chew); Global investments in the upstream (F. Birol); Total's policy in the oil and gas sector (C. de Margerie); Gaz de France's policy in the oil and gas sector (J. Abiteboul); NOC/IOC's opportunities in OPEC countries (I. Sandrea); Relationships between companies, countries and investors: How they may impact on the growth of reserves and resources (H. Le Leuch); Additional reserves: the role of new technologies - A global perspective on EORIOR (G. Fries); - Updating reservoir models with dynamic data and uncertainty quantification: an integrated approach (F. Roggero); Seismic technology for the OAPEC countries (P. Canal); Exploration knowledge and technologies: impact of progress - Statistical results (N. Alazard); Stratigraphic modelling as a key to find new potentialities in exploration (D. Granjeon); Modelling hydrocarbon migration as a tool for reserve estimation (J-L. Rudkiewicz); The contribution of surface and near surface geology to hydrocarbon discoveries (S.M. Kumati); Contribution of the exploration activity in renewing reserves - The case of Algeria (R. Lounissi); Egypt's petroleum hydrocarbon potential (H. Hataba); Future of hydrocarbon reserves in Syria (T. Hemsh); Natural gas, the fuel of choice for decades to com (M.F. Chabrelie); The role and importance of Arab natural gas in world market (M. Al-Lababidi); LNG and GTL: two pathways for natural gas utilization (C. Cameron); Yet to find hydrocarbon potential (S. Al Menhali); Libyan context of hydrocarbon reserves: abundance or scarcity? (M. Elazi)

  13. Reverse time migration of multiples for subsalt imaging

    OpenAIRE

    Liu, Yike; Chang, Xu; Jin, Degang; He, Ruiqing; Sun, Hongchuan; Zheng, Yingcai

    2011-01-01

    Some hydrocarbon reservoirs are trapped beneath salt bodies, where seismic imaging is greatly challenged due to poor illumination. Multiple reflections have different propagation wave paths from primary reflections and thus can be used to complement the illuminations where primary reflections from beneath the salt are not acquired. Consequently, migration of multiples can sometimes provide better subsalt images compared to conventional migration which uses primary reflections only. In this pa...

  14. Minneapolis Multi-Ethnic Curriculum Project--Migration Unit.

    Science.gov (United States)

    Minneapolis Public Schools, Minn. Dept. of Intergroup Education.

    The student booklet presents short chapters illustrating the migration unit of the Minneapolis Multi-Ethnic Curriculum Project for secondary schools. Sixteen brief chapters describe migration, immigration, and emigration in the United States. The first six chapters offer first person accounts of immigrants from Norway, Korea, Egypt, Hitler's…

  15. Immunoassay for petroleum hydrocarbons

    International Nuclear Information System (INIS)

    Petroleum hydrocarbon contamination of soil and ground water has become a serious environmental problem. Since the 1940s, it has been a common practice to bury fuel tanks underground to guard against fire and explosions. The leakage of petroleum fuel from these aging tanks creates a long term threat to human health. In order to location and identify these sources of contamination, an on-site screening test is very desirable. A simple, inexpensive petroleum hydrocarbon immunoassay has been developed for this purpose. The EnviroGard Petroleum Hydrocarbon test kit is designed for qualitative or semiquantitative analysis of petroleum hydrocarbon fuel in soil and ground water. The assay can be easily used on-site and takes 15 minutes to perform. Following a 2 minute methanol extraction, the test is performed in polystyrene tubes and can detect gasoline, diesel fuel, kerosene, home heating oil and other major fuels at ppm levels in soil and sub-ppm levels in water samples

  16. Thraustochytrid protists degrade hydrocarbons

    Digital Repository Service at National Institute of Oceanography (India)

    Raikar, M.T.; Raghukumar, S.; Vani, V.; David, J.J.; Chandramohan, D.

    2001-01-01

    isolation tubes with crude oil. Three isolates tested showed positive hydrophobicity of cell walls as judged by the Microbial Adhesion to Hydrocarbons (MATH) assay. Addition of Bombay High crude oil to nutrient broth slightly enhanced growth of the protists...

  17. Carbon and nitrogen isotopes in hydrocarbon research and exploration

    International Nuclear Information System (INIS)

    The present knowledge of C- and N-isotope variations in hydrocarbons is reviewed including some very recent and up to now unpublished results. Stable-isotope techniques are shown to be useful for: a) Environmental identification of organic source materials. b) Evaluation of the influence of migration. c) Recognition of bacterial degradation. d) Quantitative determination of the maturity of CH4-producing organic source materials. e) Characterization of and differentiation between various crude oil accumulations. f) Correlation of crude oils with source rocks. Especially, the maturity of CH4 as determined by isotope techniques is of considerable importance in hydrocarbon exploration

  18. Diagenesis of deeply buried Eagle Mills sandstones. Implications for paleo-fluid migration and porosity development

    Energy Technology Data Exchange (ETDEWEB)

    Dawson, W.C. [Texaco EPTD, Houston, TX (United States)

    1995-10-01

    Eagle Mills strata (Triassic-Jurassic) unconformably overlie the Paleozoic basement complex and thus, form the basal sedimentary unit within the Gulf Coast basin. Jurassic-aged basaltic dikes and sills have intruded Eagle Mills strata. These sedimentary and igneous rocks are the earliest record of Gulf of Mexico rifting. Deeply buried (15,000 to 18,000 ft.) Eagle Mills sandstone have subarkosic and sublithic modal compositions. These sandstones exhibit evidence of a complex and prolonged diagnetic history, including: early chlorite cementation; early quartz and feldspar overgrowths; early calcite and dolomite cementation; dissolution of framework grains and early carbonate cements; kaolinite precipitation; late ferroan carbonate cementation; albitization; late chlorite and anhydrite replacement; saddle dolomite cementation; and pyritization. Pyrobitumens coat early chlorite rim cements indicating that most diagenesis post-dated hydrocarbon migration. Secondary porosity development coincided with a later burial dissolution event. The Eagle Mills paragenetic sequence records progressive burial into a high-temperature diagenetic regime where thermochemical sulfate reduction was the dominant process. Marked shifts in paleo-water chemistry are recorded by the Eagle Mills diagenetic sequence. Pervasive dissolution of detrital feldspars in some Eagle Mills sandstones provides unequivocal petrographic evidence for deep-seated sourcing of diagenetic fluids, which migrated along faults, and contributed to the diagenesis of overlying Mesozoic strata. These petrographic analyses support interpretations of geochemical/fluid-flux data for the Mesozoic Gulf Coast basin.

  19. Heuristical Strategies on the Study Theme "The Unsaturated Hydrocarbons -- Alkenes"

    Science.gov (United States)

    Naumescu, Adrienne Kozan; Pasca, Roxana-Diana

    2011-01-01

    The influence of heuristical strategies upon the level of two experimental classes is studied in this paper. The didactic experiment took place at secondary school in Cluj-Napoca, in 2008-2009 school year. The study theme "The Unsaturated Hydrocarbons--Alkenes" has been efficiently learned by using the most active methods: laboratory…

  20. International Migration and Remittances

    OpenAIRE

    Dattatray Sitaram Bagade

    2012-01-01

    Human migration is a physical movement by human beings from one geographical areato another geographical area. Migration is internal as well as external. At theinternational level, no universally accepted definition for “Migrant” exists. The UniteNations defines “migration as an individual who has resided in a foreign country formore than one year irrespective of the causes, voluntary or involuntary, and the means,regular or irregular, used migrate”. Key terms of migrations is documen...

  1. Migration and trade

    OpenAIRE

    Egger, Peter H.; Ehrlich, Maximilian Von; Nelson, Douglas R.

    2011-01-01

    Theoretical and empirical research in economics suggests that bilateral migration triggers bilateral trade through a number of channels. This paper assesses the functional form of the impact of migration on trade flows in a quasi-experimental setting. We provide evidence that the relationship is not log-linear. In particular, at small levels of migration (stocks) the elasticity of trade to migration is quite high, and it declines to zero at about 4,000 immigrants. If migration stocks exceed s...

  2. Ejected Sedimentary Rocks of Mud Volcanoes as Indicators of Depositional Environments and of Hydrocarbon Generation within the South Caspian Basin, Azerbaijan

    Science.gov (United States)

    Berner, U.; Scheeder, G.; Kus, J.; Köthe, A.; Movsumova, U.

    2009-04-01

    Mud volcanoes are prominent geological features of the South Caspian Basin of Azerbaijan, one of the oldest oil producing regions worldwide. The basin is characterized by extreme sedimentation rates, which lead to the accumulation of large volumes of Mesozoic and Cenozoic sediments. These mostly unconsolidated strata reach thicknesses of up to 20 km and overlay a continental basement in the onshore part. Tectonic forces control the occurrences of mud volcanoes in regions with over-pressured subsurface sediments as mud volcanoes are closely linked to fault systems. The mud volcanoes of Azerbaijan are a surface expression of vertical hydrocarbon migration and offer the chance to investigate the subsurface by means of ejected rocks transported to the surface. These rocks of Mesozoic and Cenozoic sedimentary sequences are potential indicators of the regional hydrocarbon generation. The mud of nineteen volcano cones contained numerous ejected rock fragments, which we use to identify environmental and depositional parameters of the sediments of the Caspian Basin. We also intended to estimate the depth range from which the mud was transported to the surface using organic geochemical parameters. Mircopalaeontological investigations (calcareous nannoplankton) have been performed on selected samples. These analyses suggest that the investigated sediments are of Late Cretaceous to Palaeogene ages and relate to the stratigraphic interval during which the main hydrocarbon source rocks of Azerbaijan have been deposited. Organic geochemical, organic petrographical and mircopalaeontological investigations have been performed on selected samples of nineteen mud volcanoes. Analyses total organic carbon and total sulphur were performed on an elemental analyzer. These analyses suggest that the sediments can be classified as anoxic marine deposits whereas only few are sediments of a lacustrine environment. Bulk source rock information were obtained from RockEval pyrolysis. Resulting Hydrogen and oxygen indices indicate that the organic matter of the sediments consist mostly of mixtures of aquatic and terrestrial organic matter. The hydrocarbons of the sediments were extracted and subsequently fractionated into aliphatic, aromatic and hetero-compound groups. The amounts of extractable hydrocarbons in relation to organic carbon contents indicate that most of the ejected sedimentary rocks contain migrated hydrocarbons. All extracted hydrocarbons have been affected by secondary alterations which most likely involved biodegradation the chromatographic analyses of the aliphatic fraction indicate elevated ratios of pristane/n-C17 and phytane/n-C18 and the chromatograms generally show that the normal alkanes have been removed to a large extend. Despite of biodegardation, environmental and maturity indicative biomarkers could be identified, and C27- to C29-sterane isomers suggest a dominant imprint of aquatic organic matter on the extracted hydrocarbons. An influence of diatoms on the sterane distribution seems plausible, but an admixture of land plant material is highly likely. Homohopane isomerization ratios as well as the ratio of trisnorneohopane over trisnorhopane suggest that the extracted hydrocarbons come from a coalification range which spreads from immature to mature although, maximum maturity does not reach the peak of oil generation. C29-sterane isomerisation ratios support this finding. Vitrinite reflectance measurements on the ejected rocks indicate a similar range of maturities as suggested from biomarker analyses. However, the data indicate again that most of the investigated rocks have been impregnated by allochthonous hydrocarbons as biomarker maturities may slightly depart from the measured reflectance values. We estimated from maturity/depth conversion that the mud volcanoes along a SSW-NNE transect from the Kura Basin to the Apsheron Peninsula produce their mud from a depth range between 4000 and 5500 m corresponding to a maturity range of 0.5 to 0.65% vitrinite reflectance, although, no specific regional maturity/depth trend cou

  3. Geochemical assessment of light gaseous hydrocarbons in near-surface soils of Kutch-Saurashtra: Implication for hydrocarbon prospects

    Science.gov (United States)

    Rao, P. Lakshmi Srinivasa; Madhavi, T.; Srinu, D.; Kalpana, M. S.; Patil, D. J.; Dayal, A. M.

    2013-02-01

    Light hydrocarbons in soil have been used as direct indicators in geochemical hydrocarbon exploration, which remains an unconventional path in the petroleum industry. The occurrence of adsorbed soil gases, methane and heavier homologues were recorded in the near-surface soil samples collected from Kutch-Saurashtra, India. Soil gas alkanes were interpreted to be derived from deep-seated hydrocarbon sources and have migrated to the surface through structural discontinuities. The source of hydrocarbons is assessed to be thermogenic and could have been primarily derived from humic organic matter with partial contribution from sapropelic matter. Gas chromatographic analyses of hydrocarbons desorbed from soil samples through acid extraction technique showed the presence of methane through n-butane and the observed concentrations (in ppb) vary from: methane (C1) from 4-291, ethane (C2) from 0-84, propane (C3) from 0-37, i-butane (iC4) from 0-5 and n-butane (nC4) from 0-4. Carbon isotopes measured for methane and ethane by GC-C-IRMS, range between -42.9‰ to -13.3‰ (Pee Dee Belemnite - PDB) and -21.2‰ to -12.4‰ (PDB), respectively. The increased occurrence of hydrocarbons in the areas near Anjar of Kutch and the area south to Rajkot of Saurashtra signifies the area potential for oil and gas.

  4. Organic geochemistry of the Vindhyan sediments: Implications for hydrocarbons

    Science.gov (United States)

    Dayal, A. M.; Mani, Devleena; Madhavi, T.; Kavitha, S.; Kalpana, M. S.; Patil, D. J.; Sharma, Mukund

    2014-09-01

    The organic geochemical methods of hydrocarbon prospecting involve the characterization of sedimentary organic matter in terms of its abundance, source and thermal maturity, which are essential prerequisites for a hydrocarbon source rock. In the present study, evaluation of organic matter in the outcrop shale samples from the Semri and Kaimur Groups of Vindhyan basin was carried out using Rock Eval pyrolysis. Also, the adsorbed low molecular weight hydrocarbons, methane, ethane, propane and butane, were investigated in the near surface soils to infer the generation of hydrocarbons in the Vindhyan basin. The Total Organic Carbon (TOC) content in shales ranges between 0.04% and 1.43%. The S1 (thermally liberated free hydrocarbons) values range between 0.01-0.09 mgHC/gRock (milligram hydrocarbon per gram of rock sample), whereas the S2 (hydrocarbons from cracking of kerogen) show the values between 0.01 and 0.14 mgHC/gRock. Based on the Tmax (temperature at highest yield of S2) and the hydrogen index (HI) correlations, the organic matter is characterized by Type III kerogen. The adsorbed soil gas, CH4 (C1), C2H6 (C2), C3H8 (C3) and nC4H10, (nC4), concentrations measured in the soil samples from the eastern part of Vindhyan basin (Son Valley) vary from 0 to 186 ppb, 0 to 4 ppb, 0 to 5 ppb, and 0 to 1 ppb, respectively. The stable carbon isotope values for the desorbed methane (?13C1) and ethane (?13C2) range between -45.7‰ to -25.2‰ and -35.3‰ to -20.19‰ (VPDB), respectively suggesting a thermogenic source for these hydrocarbons. High concentrations of thermogenic hydrocarbons are characteristic of areas around Sagar, Narsinghpur, Katni and Satna in the Son Valley. The light hydrocarbon concentrations (C1-C4) in near surface soils of the western Vindhyan basin around Chambal Valley have been reported to vary between 1-2547 ppb, 1-558 ppb, 1-181 ppb, 1-37 ppb and 1-32 ppb, respectively with high concentrations around Baran-Jhalawar-Bhanpur-Garot regions (Kumar et al., 2006). The light gaseous hydrocarbon anomalies are coincident with the wrench faults (Kota - Dholpur, Ratlam - Shivpuri, Kannod - Damoh, Son Banspur - Rewa wrench) in the Vindhyan basin, which may provide conducive pathways for the migration of the hydrocarbons towards the near surface soils.

  5. HYDROCARBONS DIAGNOSTIC OF POLLUTED SOILS

    Directory of Open Access Journals (Sweden)

    Mohamed Arad

    2010-12-01

    Full Text Available Petroleum hydrocarbons are known as carcinogenic and may contaminate the environment (water, air and soil. In this study, a diagnostic of polluted soils by petroleum hydrocarbons is carried out in order to know the effect of their accumulation as well as their behavior in time. The aging factor, a source of significant changing in hydrocarbon behavior, is integrated on two sites of an industrial refinery as experimental samples. The first site is recently polluted by hydrocarbons while the second is a previously polluted site.The results indicate that the concentration of hydrocarbons on the surface of the first site is greater and remains stable in time, as for the second site, hydrocarbons concentration on the surface is also important and undergoes a weak reduction. At a depth of one meter hydrocarbons exist at a greater concentration. This shows that obstinate hydrocarbons are an environmental danger for fauna and flora.

  6. HYDROCARBONS DIAGNOSTIC OF POLLUTED SOILS

    OpenAIRE

    Mohamed Arad; Abdelkader Anouzla; Mohamed Safi; Salah Souabi; Hicham Rhbal

    2010-01-01

    Petroleum hydrocarbons are known as carcinogenic and may contaminate the environment (water, air and soil). In this study, a diagnostic of polluted soils by petroleum hydrocarbons is carried out in order to know the effect of their accumulation as well as their behavior in time. The aging factor, a source of significant changing in hydrocarbon behavior, is integrated on two sites of an industrial refinery as experimental samples. The first site is recently polluted by hydrocarbons while the s...

  7. NNDC database migration project

    International Nuclear Information System (INIS)

    NNDC Database Migration was necessary to replace obsolete hardware and software, to be compatible with the industry standard in relational databases (mature software, large base of supporting software for administration and dissemination and replication and synchronization tools) and to improve the user access in terms of interface and speed. The Relational Database Management System (RDBMS) consists of a Sybase Adaptive Server Enterprise (ASE), which is relatively easy to move between different RDB systems (e.g., MySQL, MS SQL-Server, or MS Access), the Structured Query Language (SQL) and administrative tools written in Java. Linux or UNIX platforms can be used. The existing ENSDF datasets are often VERY large and will need to be reworked and both the CRP (adopted) and CRP (Budapest) datasets give elemental cross sections (not relative I?) in the RI field (so it is not immediately obvious which of the old values has been changed). But primary and secondary intensities are now available on the same scale. The intensity normalization has been done for us. We will gain access to a large volume of data from Budapest and some of those gamma-ray intensity and energy data will be superior to what we already have

  8. Marriage, money and migration

    OpenAIRE

    A?stro?m, Johanna

    2009-01-01

    The thesis consists of a summary and four self-contained papers. Paper [I] examines the effects of interregional migration on gross earnings in married and cohabiting couples. In particular, we examine the link between education level and income gains. We find that pre-migration education level is a key determinant of migration and economic outcomes and is also a determinant of the effect of migration on income distribution within the household. The positive average effect on household earnin...

  9. Migration and Adult Education

    Science.gov (United States)

    Gois, William

    2007-01-01

    The objective of this paper is to highlight the role of adult education as a tool in addressing labour migration issues, specifically those concerning the protection of migrant workers' rights and the transformation of the impact of migration into positive holistic developmental gains. The view of labour migration as a means to forge the economic…

  10. More Myths of Migration.

    Science.gov (United States)

    Basch, Linda; Lerner, Gail

    1986-01-01

    Challenges "myths" about women and migration, including (1) the causes of migration are economic, not racism; (2) migrant women receive support from feminist groups and trade unions; (3) transnational corporations are positive forces in developing nations; (4) migration today has little impact on family life; and (5) most migrants cluster in…

  11. [Secondary achalasia].

    Science.gov (United States)

    Arnon, R; Fich, A; Bar-Ziv, J

    1993-08-01

    Achalasia is usually a primary disorder of esophageal motility, but has been described in association with other pathological processes, such as malignancy. A 79-year-old man with achalasia secondary to gastric adenocarcinoma is presented. The differential diagnosis of secondary achalasia includes infectious and infiltrative disease and neuropathy, but mainly malignant diseases. The clinical criteria found for achalasia secondary to malignancy included older age at diagnosis, brief duration of symptoms, and weight loss. While upper gastrointestinal x-rays and computerized tomographic scanning may be helpful, the most reliable diagnostic tool is esophago-gastro-duodenoscopy. This is a terminal disease with short life expectancy. Yet making the correct diagnosis can save the patient from futile treatment with muscle relaxants and endoscopic balloon dilatation, the accepted therapeutic measures in primary achalasia. PMID:8225085

  12. Membrane separation of hydrocarbons

    Science.gov (United States)

    Chang, Y. Alice (Des Plaines, IL); Kulkarni, Sudhir S. (Hoffman Estates, IL); Funk, Edward W. (Highland Park, IL)

    1986-01-01

    Mixtures of heavy oils and light hydrocarbons may be separated by passing the mixture through a polymeric membrane. The membrane which is utilized to effect the separation comprises a polymer which is capable of maintaining its integrity in the presence of hydrocarbon compounds and which has been modified by being subjected to the action of a sulfonating agent. Sulfonating agents which may be employed will include fuming sulfuric acid, chlorosulfonic acid, sulfur trioxide, etc., the surface or bulk modified polymer will contain a degree of sulfonation ranging from about 15 to about 50%. The separation process is effected at temperatures ranging from about ambient to about 100.degree. C. and pressures ranging from about 50 to about 1000 psig.

  13. Biogeochemistry of Halogenated Hydrocarbons

    Science.gov (United States)

    Adriaens, P.; Gruden, C.; McCormick, M. L.

    2003-12-01

    Halogenated hydrocarbons originate from both natural and industrial sources. Whereas direct anthropogenic emissions to the atmosphere and biosphere are often easy to assess, particularly when they are tied to major industrial activities, the attribution of emissions to other human activities (e.g., biomass burning), diffuse sources (e.g., atmospheric discharge, run off), and natural production (e.g., soils, fungi, algae, microorganisms) are difficult to quantify. The widespread occurrence of both alkyl and aryl halides in groundwater, surface water, soils, and various trophic food chains, even those not affected by known point sources, suggests a substantial biogeochemical cycling of these compounds (Wania and Mackay, 1996; Adriaens et al., 1999; Gruden et al., 2003). The transport and reactive fate mechanisms controlling their reactivity are compounded by the differences in sources of alkyl-, aryl-, and complex organic halides, and the largely unknown impact of biogenic processes, such as enzymatically mediated halogenation of organic matter, fungal production of halogenated hydrocarbons, and microbial or abiotic transformation reactions (e.g., Asplund and Grimvall, 1991; Gribble, 1996; Watling and Harper, 1998; Oberg, 2002). The largest source may be the natural halogenation processes in the terrestrial environment, as the quantities detected often exceed the amount that can be explained by human activities in the surrounding areas ( Oberg, 1998). Since biogeochemical processes result in the distribution of a wide range of halogenated hydrocarbon profiles, altered chemical structures, and isomer distributions in natural systems, source apportionment (or environmental forensics) can often only be resolved using multivariate statistical methods (e.g., Goovaerts, 1998; Barabas et al., 2003; Murphy and Morrison, 2002).This chapter will describe the widespread occurrence of halogenated hydrocarbons, interpret their distribution and biogeochemical cycling in light of natural and anthropogenic sources, biotic and abiotic reactivity, and prevailing cycling mechanisms. Specific emphasis will be placed on the potential role of biotic and abiotic transformation reactions in soil, water, and sediment environments resulting in environmental sequestration and phase transfer.

  14. [Secondary hyperparathyroidism].

    Science.gov (United States)

    Diaconescu, M R; Costea, I; Terinte, R; Diaconescu, S; Covic, M; Zbranca, E

    1995-01-01

    Secondary (renal) hyperparathyroidism appears in chronic renal failure, sometimes in patients on chronic dialysis. Other causes includes rickets and osteomalacia. These diseases are associated with poor calcium and vitamin D absorbtion from the small bowel. Two patients with chronic renal failure maintained on chronic haemodialysis from two and three years, respectively underwent subtotal parathyroidectomy: removal of three glands and preserving a half of a gland in situ. The diagnosis and surgical indication was made upon clinical (bone pain and severe itching), radiological (demineralisation, ectopic calcifications) and biochemical (hypercalcemia, hyperphosphoremia, increased values of alkaline phosphatases) arguments. Postoperatively the improvement is defined by a return to normal in the clinical, laboratory and radiological parametres. The most appropriate operation for secondary hyperparathyroidism is still unresolved one of two techniques is performed according to the preference of the surgeon: subtotal parathyroidectomy or total parathyroidectomy with autotransplantation of parathyroid fragments into forearm muscle. PMID:7496211

  15. A dengue model incorporating saturation incidence and human migration

    Science.gov (United States)

    Gakkhar, S.; Mishra, A.

    2015-03-01

    In this paper, a non-linear model has been proposed to investigate the effects of human migration on dengue dynamics. Human migration has been considered between two patches having different dengue strains. Due to migration secondary infection is possible. Further, the secondary infection is considered in patch-2 only as strain-2 in patch-2 is considered to be more severe than that of strain-1 in patch-1. The saturation incidence rate has been considered to incorporate the behavioral changes towards epidemic in human population. The basic reproduction number has been computed. Four Equilibrium states have been found and analyzed. Increasing saturation rate decreases the threshold thereby enhancing the stability of disease-free state in both the patches. Control on migration may lead to change in infection level of patches.

  16. Characterization of hydrocarbon contaminated areas by multivariate statistical analysis: Case studies.

    Science.gov (United States)

    Saenz, G; Pingitore, N E

    1991-01-01

    Analysis of soil gases is a relatively rapid and inexpensive method to delineate and measure hydrocarbon contamination in the subsurface caused by diesel or gasoline. Techniques originally developed for petroleum exploration have been adapted to tracking hydrocarbons which have leaked or spilled at or below the earth's surface.Discriminant analysis (a multivariate statistical technique) is used to classify soil gas samples of C1 to C7 hydrocarbons as biogenic (natural soil gases) or thermogenic (contaminant hydrocarbons). Map plots of C1 to C7 total interstitial hydrocarbons, C2 to C7 interstitial hydrocarbons, and C1/?C n rations are used to further delineate and document the extent and migration of contamination.Three case studies of the technique are presented: each involves leakage of hydrocarbons from underground storage tanks. Soil gas analysis clearly defines the spread of contamination and can serve as the basis for the correct placement of monitoring wells. The method proved to be accurate, rapid, and cost-effective; it therefore has potential for widespread application to the identification of soil and groundwater contaminated by hydrocarbons. PMID:24233510

  17. Suicidal Ideation and Migration Aspirations among Youth in Central Mexico

    OpenAIRE

    Steven Hoffman

    2013-01-01

    Over the past 100 years the state of Guanajuato has consistently been one of the highest migrant sending states in Mexico. Youth living in high migratory states such as Guanajuato are heavily influenced by the expectation that they will travel to the US, and research has shown that those who do not migrate may be looked down upon by members of their community. This secondary analysis looks at the connection between suicidal ideation and migration aspirations among a group of adolescents livin...

  18. Endoscopic management of migrated biliary stent causing sigmoid perforation

    OpenAIRE

    Jafferbhoy, Sadaf F; Scriven, Peter; Bannister, Jeremy; Shiwani, Muhammad Hanif; Hurlstone, Paul

    2011-01-01

    Endoscopically deployed biliary stents are a well established method for dealing with biliary diseases. Perforation of the gut secondary to migrated biliary stent is reported in less than 1% cases. The authors present the first case of a colonic perforation from migrated biliary stent which was managed endoscopically. An 82-year-old female had a biliary stent for a postcholecystectomy bile leak and presented 6 months later with left iliac fossa pain. Barium enema showed a stent perforating th...

  19. Migration and stratification

    OpenAIRE

    Jasso, Guillermina

    2011-01-01

    Migration and stratification are increasingly intertwined. One day soon it will be impossible to understand one without the other. Both focus on life chances. Stratification is about differential life chances - who gets what and why - and migration is about improving life chances - getting more of the good things of life. To examine the interconnections of migration and stratification, we address a mix of old and new questions, carrying out analyses newly enabled by a unique new data set on r...

  20. Material erosion and migration in tokamaks

    International Nuclear Information System (INIS)

    Material migration is one of the outstanding issues facing successful long pulse, high power tokamak operation, both for the next step device, ITER, and the longer term economic and technological viability of fusion power. Erosion of tokamak first wall surfaces may occur via a number of processes, both steady state and transient, the relative importance of each of which depends sensitively on the nature of the driving mechanism and the wall material itself. The subsequent transport of this eroded material through the plasma and its redeposition, often in locations remote from the point of release, constitute the foundation of material migration. Such material movement is intimately linked with the critical issue of tritium retention (via the process of co-deposition), which, in ITER and beyond, will determine the duration over which the tokamak may be operated before removal of the retained fraction is imposed by nuclear safety restrictions. Of the three processes: erosion, large-scale material transport and co-deposition, transport is currently the least understood, leading to large uncertainties in the predicted T-retention in ITER, independently of the chosen wall materials. The low duty cycle and reduced energy and particle fluxes to first wall surfaces in today's tokamaks mean that the phenomena of migration is of no practical consequence to their operation. In steady state reactor-class devices, however, annual migration rates are currently predicted to be in th rates are currently predicted to be in the range of tons, even in the absence of transient events. These estimates are nevertheless associated with considerable uncertainty and, although the situation is unlikely to be completely resolved by the time ITER is constructed, a clearer understanding of the global migration picture is emerging from ongoing physics studies in current devices. In particular, the influential role of erosion at main chamber surfaces, followed by subsequent transfer to the divertor and the delicate erosion/deposition balance in the divertor itself is now recognised, even though the use of carbon in many tokamaks adds significant complexity to the problem through the requirement to account for hydrocarbon chemistry. This contribution aims both to review our current understanding of erosion and migration by compiling current experimental and modelling results, and to discuss key areas of uncertainty preventing the accurate prediction of migration rates in ITER and future reactors. Plans for a large scale investigation of migration and T-retention at JET with the hitherto untested ITER first wall material mix will also be discussed. (Author)

  1. ADVANCES IN HYDROCARBON TECHNOLOGIES

    Directory of Open Access Journals (Sweden)

    Martin Bajus

    2007-07-01

    Full Text Available This paper provides an overview about today’s and future trends in using hydrocarbon technologies and related hydrogen technologies. The content of this presentation is devoted to hydrogen/bio-hydrogen production – with focus on-board fuel reforming and vehicular hydrogen storage. Hydrogen storage is widely recognized as a major technological barrier to the successful implementation of fuel cells for transportation and portable applications. The paper shows that GTL technology is undergoing a renewal of its innovative process. For more detailed information the interested reader is invited to consult the dedicated papers cited throughout the overview.

  2. Hydrocarbon potential of Ordovician and Silurian rocks. Siljan Region (Sweden)

    Energy Technology Data Exchange (ETDEWEB)

    Berner, U. [Bundesanstalt fuer Geowissenschaften und Rohstoffe (BGR), Hannover (Germany); Lehnert, O. [Erlangen-Nuernberg Univ., Erlangen (Germany); Meinhold, G. [Goettingen Univ. (Germany)

    2013-08-01

    Hydrocarbon exploration in the vicinity of Europe's largest impact structure (Siljan, Central Sweden) focused for years on abiogenic concepts and largely neglected state of the art knowledge on hydrocarbon generation via thermal decomposition of organic matter. In our study we use sedimentary rocks obtained from three drill sites (Mora001, Stumsnaes 1 and Solberga 1) within the ring structure around the central uplift to investigate the hydrocarbon potential of Ordovician and Silurian strata of the region and also for comparison with the shale oil and gas potential of age equivalent rocks of the Baltic Sea. Elemental analyses provided information on concentrations of carbonate and organic carbon, total sulfur as well as on the composition of major and minor elements of the sediments. The data has been used to evaluate the depositional environment and possible diagenetic alterations of the organic matter. RockEval pyrolysis and solvent hydrocarbon extraction gave insight into the hydrocarbon generation potential and the type and thermal maturity of the sediments. From the geochemistry data of the studied wells it is obvious that changes of depositional environments (lacustrine - marine) have occurred during Ordovician and Silurian times. Although, the quality of the organic matter has been influenced in marine and brackish environments through sulfate reduction, we observe for a number of marine and lacustrine sediments a good to excellent preservation of the biological precursors which qualify the sediments as hydrocarbon source rocks (Type II kerogens). Lacustrine source rocks show a higher remaining hydrocarbon potential (up to {proportional_to}550 mg HC per g C{sub org}) than those of marine or brackish environments. Our investigations indicate that the thermal maturity of organic matter of the drill sites has reached the initial stage of oil generation. However, at Mora001 some of the sediments were stained with oil indicating that hydrocarbons have migrated from more mature parts of the Siljan structure into the marginally mature sediments. Likely sources could have been the Upper Ordovician Fjaecka Shale deposited in a brackish to lacustrine environment or the Lower Silurian Kallholm Fm. of similar environments which both have an excellent hydrocarbon potential for oil and gas. Marine source rocks of the Siljan region may be compatible to unconventional shale targets of the German region of the Baltic Sea provided appropriate thermal maturities are not exceeded.

  3. What Are Migration Networks?

    OpenAIRE

    Bauer, Thomas; Gang, Ira; Epstein, Gil

    2000-01-01

    Migration networks are usually captured by the number of people from the migrant?s country in the host region. Using Mexican migration data, we analyze the effects of the usual network variable and two additional origin-village-specific variables on migrants? location choice.

  4. Monarchs and Migration

    Science.gov (United States)

    0000-00-00

    A large resource of information about Monarch butterflies, migration, metamorphosis, and conservation. Many photos from various places highlight the information. This is a teaching focused set of pages. Of major interest are their many links, which deal with migration routes, roosting sites, and various other activities of interest.

  5. Environmental change and migration.

    Czech Academy of Sciences Publication Activity Database

    Stojanov, Robert

    Santa Barbara, Calif : Praeger, 2012 - (Segal, U.; Elliot, D.), s. 55-89 ISBN 978-0-313-37807-2 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0073 Institutional research plan: CEZ:AV0Z60870520 Keywords : migration processes * environmental change * climate change * environmental migrants * human migration Subject RIV: AO - Sociology, Demography

  6. Diterpenoid tetracyclic hydrocarbons of petroleum

    Energy Technology Data Exchange (ETDEWEB)

    Vorob' eva, N.S.; Zemskova, Z.K.; Pekh, T.I.; Petrov, A.A.

    1987-08-01

    Diterpenoid hydrocarbons are fairly widespread in various caustobioliths. However, if petroleums contain mainly acyclic diterpenoids (phytane, pristane and norpristane), cyclic diterpaenes such as fichtelite, pimarane, iosene (kaurane) and hibbane are often found in hydrocarbons isolated from coal and shale. Recent advances in the chemistry of diterpenoids isolated from caustobioliths, are described in a separate paper. Much less is known about petroleum polycyclic diterpenoid hydrocarbons, particularly those with four saturated rings. A series of tetracyclic hydrocarbons C/sub 19/H/sub 32/ (molar mass 260), found in a number of light petroleums and gas condensates from the Jura deposits of Central Kara-Kum (Turkmen S.S.R.), are examined here. These hydrocarbons are present in petroleums and condensates from the Davaly, Erden, Ortakak, Southern Beuideshik deposits, they are always identical and occur in the same ratios. The composition of the tretracyclanes isolated from the Ortakak gas condensates (well 17) will be examined in detail.

  7. Sandstone geometry, porosity and permeability distribution, and fluid migration in eolian system reservoirs

    Science.gov (United States)

    Lupe, Robert; Ahlbrandt, Thomas S.

    1975-01-01

    Upper Paleozoic to Mesozoic eolian blanket sandstones of the Colorado Plateau and the Rocky Mountains of Colorado and southern Wyoming are texturally complex. As petroleum reservoirs they commonly have poor performance histories. They contain the sediments of a depositional system comprised of three closely associated depositional subenvironments: dune, interdune, and extradune. Sediments of each subenvironment have different textural properties which resulted from different depositional processes. Dune sediments are usually more porous and permeable than interdune or extradune sediments and may be better quality reservoirs than interdune or extradune sediments. Interdune sediments are here restricted to those nondune sediments deposited in the relatively flat areas between dunes. Extradune sediments (a new term) include all deposits adjacent to a dune field and are mainly subaqueous deposits. Dune sediments may be enveloped by extradune sediments as the depositional system evolves resulting in a texturally inhomogeneous reservoir having poor fluid migration properties. This model of textural inhomogeneity in eolian blanket sandstones. was applied to the Weber (Tensleep) Sandstone in Brady, Wertz, and Lost Soldier fields, Sweetwater County, Wyoming. Data were obtained from both outcrop and subsurface and included environmental interpretation, textural analysis, and plotting of the distribution of depositional subenvironments. As predicted from the model, the texture of dune sediments in Brady field differed markedly from interdune and extradune sediments. The predicted geometric distribution of subenvironments was confirmed in Lost Soldier and Wertz fields. However, secondary cementation and fracturing there has obscured the original porosity and permeability contrasts. The porosity and permeability distribution, a characteristic depending partly on depositional processes, could impede fluid migration in the reservoir and significantly reduce recovery of hydrocarbons.

  8. Modeling of hydrocarbon fueling

    International Nuclear Information System (INIS)

    We have compared a database of rate coefficients for CH4 with experiments on PISCES-A to understand the role of carbon-based impurities in determining the fueling profile of carbon-dominated machines. A three-dimensional Monte Carlo model that embodies the Ehrhardt-Langer CH4 breakup scheme has been developed. The model has been compared with spectroscopic observations of the spatial variation of the hydrocarbon product decay rates, and reasonable agreement has been found. The comparison is sensitive to the non-Maxwellian electron distribution and to observed spatial inhomogeneities in the electron density and temperature profiles. Applications of the model to parameters characteristic of the tokamak scrape-off layer are presented

  9. Canada's hydrocarbon processing evolution

    International Nuclear Information System (INIS)

    The development of petroleum refining, petrochemicals and natural gas industries in Canada are discussed together with future issues and prospects. Figures give data on (a) refined products trade 1998; (b) refining capacity; (c) product demand 1980-1999; (d) refinery crude runs and capacity; (e) refining and marketing, historical returns 1993-1999; (f) processing power index for Canada and USA; (g) ethylene capacity; (eye) Montreal petrochemical capacities; (j) Sarnia petrochemical capacities in 2000; (k) Alberta petrochemicals capacities 2001; (l) ethylene net equivalent trade; (m) ethylene costs 1999 for W. Canada and other countries. It was concluded that the hydrocarbon processing business continues to expand in Canada and natural gas processing is likely to increase. Petrochemicals may expand in W. Canada, possibly using feed stock from the Far North. Offshore developments may stimulate new processing on the E. Coast

  10. Subduction zone earthquake probably triggered submarine hydrocarbon seepage offshore Pakistan

    Science.gov (United States)

    Fischer, David; José M., Mogollón; Michael, Strasser; Thomas, Pape; Gerhard, Bohrmann; Noemi, Fekete; Volkhard, Spiess; Sabine, Kasten

    2014-05-01

    Seepage of methane-dominated hydrocarbons is heterogeneous in space and time, and trigger mechanisms of episodic seep events are not well constrained. It is generally found that free hydrocarbon gas entering the local gas hydrate stability field in marine sediments is sequestered in gas hydrates. In this manner, gas hydrates can act as a buffer for carbon transport from the sediment into the ocean. However, the efficiency of gas hydrate-bearing sediments for retaining hydrocarbons may be corrupted: Hypothesized mechanisms include critical gas/fluid pressures beneath gas hydrate-bearing sediments, implying that these are susceptible to mechanical failure and subsequent gas release. Although gas hydrates often occur in seismically active regions, e.g., subduction zones, the role of earthquakes as potential triggers of hydrocarbon transport through gas hydrate-bearing sediments has hardly been explored. Based on a recent publication (Fischer et al., 2013), we present geochemical and transport/reaction-modelling data suggesting a substantial increase in upward gas flux and hydrocarbon emission into the water column following a major earthquake that occurred near the study sites in 1945. Calculating the formation time of authigenic barite enrichments identified in two sediment cores obtained from an anticlinal structure called "Nascent Ridge", we find they formed 38-91 years before sampling, which corresponds well to the time elapsed since the earthquake (62 years). Furthermore, applying a numerical model, we show that the local sulfate/methane transition zone shifted upward by several meters due to the increased methane flux and simulated sulfate profiles very closely match measured ones in a comparable time frame of 50-70 years. We thus propose a causal relation between the earthquake and the amplified gas flux and present reflection seismic data supporting our hypothesis that co-seismic ground shaking induced mechanical fracturing of gas hydrate-bearing sediments creating pathways for free gas to migrate from a shallow reservoir within the gas hydrate stability zone into the water column. Our results imply that free hydrocarbon gas trapped beneath a local gas hydrate seal was mobilized through earthquake-induced mechanical failure and in that way circumvented carbon sequestration within the sediment. These findings lead to conclude that hydrocarbon seepage triggered by earthquakes can play a role for carbon budgets at other seismically active continental margins. The newly identified process presented in our study is conceivable to help interpret data from similar sites. Reference: Fischer, D., Mogollon, J.M., Strasser, M., Pape, T., Bohrmann, G., Fekete, N., Spieß, V. and Kasten, S., 2013. Subduction zone earthquake as potential trigger of submarine hydrocarbon seepage. Nature Geoscience 6: 647-651.

  11. Determinants of Migration, Revisited

    OpenAIRE

    Alexander, Gigi; Foley, Maggie

    2014-01-01

    This empirical study investigates the impact on net state in-migration over the 2000-2003 period of a variety of economic and non-economic factors and thereby serves as a robustness test of previous studies. The empirical estimates indicate that the net state in-migration rate was an increasing function of median family income or expected median family income on the one hand and a decreasing function of the average cost of living. In addition, net state in-migration was an increasing function...

  12. Fiscal and migration competition

    OpenAIRE

    Razi?n, Assaf; Sadka, Efraim

    2010-01-01

    It is often argued that tax competition may lead to a 'race to the bottom'. This result may indeed hold in the case of factor mobility (such as capital). However, in this paper we emphasize the unique feature of labor migration, that may nullify the'race to the bottom' hypothesis. Labor migration is governed not only by net-of-tax factor rewards, but rather importantly also by the benefits that the welfare state provides. The paper analyzes fiscal competition with and without migration in a t...

  13. Forced Migration Projects

    Science.gov (United States)

    The Forced Migration Projects (FMP), operating under the auspices of the Open Society Institute (OSI), monitor developments in the Americas, the former Yugoslavia, and the former Soviet Union to identify the social, political, and economic conditions that cause the forced dislocations of people. This Website provides background information about the projects as well as full-text access to several FMP publications including The Forced Migration Monitor, a series of special reports on refugees and migration, recent news and articles on germane issues, and FM Alert, an electronic bulletin service. In addition, the site compiles a list of refugee-related links and hosts a discussion forum.

  14. Groundwater recharge as a mechanism to replenish sulfate for natural attenuation of hydrocarbon plumes

    International Nuclear Information System (INIS)

    Intrinsic biodegradation plays a critical role in limiting the lateral migration of groundwater plumes contaminated with petroleum. As such, bioremediation is often considered as a site management and remediation strategy. Various electron acceptors exist within different zones in hydrocarbon plumes. Bacterial sulfate reduction is a dominant terminal electron accepting process in the natural attenuation of hydrocarbons in groundwater. Therefore, the addition of sulfate can enhance the biodegradation of hydrocarbons in groundwater. This paper presented the results of two field studies in southern Alberta that showed evidence that seasonal recharge is a significant mechanism to replenish sulfate as an electron acceptor in dissolved petroleum hydrocarbon plumes in groundwater. The first site was a natural gas well site, while the other was at a natural gas processing plant. BTEX (benzene, toluene, ethylbenzene and xylenes) was the contaminant of primary concern in plumes derived from natural gas condensates at the 2 field sites. The plumes showed evidence of downward migration of sulfate from the unsaturated zone during seasonal groundwater recharge. There was subsequent consumption of the sulfate by microbial reduction, associated with plume biodegradation. High water-soluble sulfate concentrations were found in the vadose zones. These results were in good agreement with results from other studies, but it was suggested that more research is needed to quantify the sulfat research is needed to quantify the sulfate replenishment process to identify the relationship between sulfate reduction and hydrocarbon degradation, and to test the supplementation of sulfate. 18 refs., 10 figs

  15. Migration = cloning; aliasiing

    DEFF Research Database (Denmark)

    Hüttel, Hans; Kleist, Josva

    1999-01-01

    In Obliq, a lexically scoped, distributed, object-oriented programming language, object migration was suggested as the creation of a copy of an object’s state at the target site, followed by turning the object itself into an alias, also called surrogate, for the remote copy. We consider the creation of object surrogates as an abstraction of the abovementioned style of migration. We introduce Øjeblik, a distribution-free subset of Obliq, and provide three different configuration-style semantics, which only differ in the respective aliasing model. We show that two of the semantics, one of which matches Obliq’s implementation, render migration unsafe, while our new proposal for a third semantics is provably safe. Our work suggests a straightforward repair of Obliq’s aliasing model such that it allows programs to safely migrate objects.

  16. Students' Misconceptions about U.S. Westward Migration

    Science.gov (United States)

    Ferretti, Ralph P.; MacArthur, Charles A.; Okolo, Cynthia M.

    2007-01-01

    Fifth-grade students with learning disabilities (LD) and their typically achieving (TA) peers participated in an 8-week investigation about 19th-century U.S. westward migration. During their investigations, the students analyzed primary and secondary sources to understand the experiences of these emigrants and Native peoples. The analysis of…

  17. Migration and Place Attractiveness

    OpenAIRE

    Niedomysl, Thomas

    2006-01-01

    The thesis includes six self-contained papers that from various perspectives examine place attractiveness and migration in Sweden. Paper I provides an extensive overview of Swedish municipalities’ place marketing engagement to attract in-migrants, based on survey responses from 220 municipalities. The results suggest that, although this kind of marketing has become more prominent during the last few years, there is little evidence of any significant effects on migration flows. Paper II ad...

  18. Essays on international migration

    OpenAIRE

    Chowdhury, Mehdi Mahmud

    2011-01-01

    In recent time efforts are observed in re-evaluating the linkage between economic development and international migration. The thesis can be considered as an attempt to add something to those efforts. In this thesis we mainly analyse the effects of competition among the countries in international labour market and effects of migration on the research activities of firms. As appeared, these two issues so far have not received much attention of economic literature. We analyse the above men...

  19. Migration of Interplanetary Dust

    OpenAIRE

    Ipatov, S. I.; Mather, J. C.; Taylor, P. A.

    2003-01-01

    We numerically investigate the migration of dust particles with initial orbits close to those of the numbered asteroids, observed trans-Neptunian objects, and Comet Encke. The fraction of silicate asteroidal particles that collided with the Earth during their lifetime varied from 1.1% for 100 micron particles to 0.008% for 1 micron particles. Almost all asteroidal particles with diameter d>4 microns collided with the Sun. The peaks in the migrating asteroidal dust particles'...

  20. Migration and Culture

    OpenAIRE

    Epstein, Gil S.; Gang, Ira N.

    2010-01-01

    Culture is not new to the study of migration. It has lurked beneath the surface for some time, occasionally protruding openly into the discussion, usually under some pseudonym. The authors bring culture into the open. They are concerned with how culture manifests itself in the migration process for three groups of actors: the migrants, those remaining in the sending areas, and people already living in the recipient locations. The topics vary widely. What unites the authors is an understanding...

  1. Subsurface fate of spilled petroleum hydrocarbons in continuous permafrost

    Science.gov (United States)

    McCarthy, K.; Walker, L.; Vigoren, L.

    2004-01-01

    Accidental releases of approximately 2000 m3 of fuel have resulted in subsurface contamination adjacent to Imikpuk Lake, a drinking-water source near Barrow, AK. This paper presents a conceptual model of the distribution and transport of subsurface free-phase hydrocarbons at this site. The mean annual temperature in Barrow is -13 ??C, and average monthly temperatures exceed 0 ??C only during the months of June, July, and August. As a result, the region is underlain by areally continuous permafrost that extends to depths of up to 300 m and constrains subsurface hydrologic processes to a shallow zone that temporarily thaws each summer. During the 1993 and 1994 thaw seasons, the measured depth of thaw varied across the site from approximately 0.5 to 2 m. However, exploratory borings in 1995 showed that free-phase hydrocarbons were present at depths greater than 3 m, indicating that permafrost at this site is not a barrier to the vertical migration of nonaqueous-phase liquids. In 1996, a subsurface containment barrier was installed to prevent lateral movement of contaminated water to Imikpuk Lake, and a recovery trench was excavated upgradient of the barrier to facilitate removal of free-phase hydrocarbons. Free-phase hydrocarbons were recovered from the trench during 1996, 1997, and 1998. Recovery rates diminished over this time, and in 1999, no further product was recovered and the recovery operation was halted. Subsequent exploratory borings in 2001 and 2002 have revealed that some product remains in the subsurface. Data indicate that this remaining product exists in small discrete pockets or very thin layers of hydrocarbon floating on brine. These small reservoirs appear to be isolated from one another by relatively impermeable permafrost. Published by Elsevier B.V.

  2. MODERN MIGRATION POLICY OF RUSSIA

    Directory of Open Access Journals (Sweden)

    Kobylinsky S. V.

    2014-11-01

    Full Text Available Several peculiarities of the implementation of migration policy in the Russian Federation were considered in this article. We have shown main provisions on refugees and forced migrants from the Ukraine and labor migration. On the basis of the study we have suggested an improvement of migration legislation, in particular, creation of a single codex and migration police

  3. Migration and malaria.

    Science.gov (United States)

    Jitthai, Nigoon

    2013-01-01

    Migration is an important global issue as poorly managed migration can result in a diversity of problems, including an increase in the transmission of diseases such as malaria. There is evidence to suggest that malaria is no longer a forest-dependent disease and may largely be affected by population movements, mostly to agricultural areas. While internal and transnational migration has different legal implications in most countries, both types of migration occur for the same reasons; economic and/ or safety. Although migration in itself is not a definitive risk for malaria, several factors can put, migrants and local communities alike, in vulnerable situations. In particular, infrastructure and rural development, deforestation for logging and economic farming, political movements, and natural disasters are some of the major factors that push and pull people in and out of malaria-endemic areas. Therefore, understanding the changing socio-environmental situation as well as population movements and their associated risks for malaria infection, is critical for malaria control, containment, and elimination. Efforts to address these issues should include advocacy, mapping exercises and expanded/ strengthened surveillance to also include migrant health information systems. Malaria related information, prevention measures, and early diagnosis and appropriate treatment should be made easily accessible for migrants regardless of their migration status; not only to ensure that they are equipped with appropriate knowledge and devices to protect themselves, but also to ensure that they are properly diagnosed and treated, to prevent further transmission, and to ensure that they are captured by the surveillance system. PMID:24159832

  4. Lithium aluminates for separating hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Burba, J.L. III

    1984-02-07

    Particles of crystalline LiX-2Al(OH)/sub 3/-nH/sub 2/O, where X is a monovalent, divalent, or trivalent anion, especially chlorine, are useful in separating hydrocarbons according to boiling point ranges.

  5. Experimental investigation of hydrocarbon formation and transformation under Earth´s upper mantle conditions

    OpenAIRE

    Kolesnikov, Anton

    2010-01-01

    The theory of the abyssal abiotic petroleum origin considers oil and natural gas to begenerated in the Earth’s upper mantle. Hydrocarbons migrate further through the deep faults into the Earth’s crust, where they can form oil and gas deposits in any kind of rock in any kind of structural position. Until recently one of the main obstacles for further development of this theory has been the lack of the data covering processes of generation and transformations of hydrocarbons. Experimental d...

  6. DETERMINATION OF SECONDARY ORGANIC AEROSOL PRODUCTS FROM THE PHOTOOXIDATION OF TOLUENE AND THEIR IMPLICATIONS IN AMBIENT PM2.5

    Science.gov (United States)

    Laboratory study was carried out to investigate the secondary organic aerosol products from photooxidation of the aromatic hydrocarbon toluene. The laboratory experiments consisted of irradiating toluene/propylene/NOX/air mixtures in a smog chamber operated in the dynamic mode...

  7. Effects of lichens on uranium migration

    International Nuclear Information System (INIS)

    The lichen Trapelia involuta from uraniferous spoil heaps in Cornwall, England, growing directly on the secondary uranium minerals, metazeunerite and metatorbernite, was examined by field-emission scanning electron microscopy and transmission electron microscopy to assess the effect of Trapelia on uranium migration. We observed metazeunerite, sericite and scorodite as well as unidentified Fe-, Pb/As-, Fe/As-, Al/P-, Pb-bearing minerals concentrated in the lichen exciple and medulla. In addition, metazeunerite also occurred in the epithecium. The chemistries, sizes, and occurrences of the above minerals in the lichen suggest that fixation of U as well as Pb, As, Fe, and Al is dependent on lichen physiological processes. We suggest Trapelia accumulates these elements from groundwater and precipitates the above minerals within specific tissues. Our results indicate that some lichens retard uranium migration by accumulating uranium from groundwater and forming uranium-bearing minerals within their tissues. Copyright (2001) Material Research Society

  8. Migration behaviour of iodine in nuclear fuel

    International Nuclear Information System (INIS)

    A novel out-reactor method has been further developed for investigating the migration behaviour of fission products in UO2 nuclear fuel, which allows the effects of thermal diffusion. radiation damage and local segregation to be independently assessed. Tailored concentration profiles of any desired species are first created in the near-surface region of polished samples by ion implantation. The impact of either thermal annealing or simulated fission is then precisely determined by depth profiling with high-performance secondary ion mass spectrometry (SIMS). Comparison of iodine migration in U02 wafers that had been ion-implanted to fluences spanning five orders of magnitude has revealed subtle radiation-damage effects and a pronounced concentration dependence for thermal diffusion. At concentrations above ?1016 atoms/cm3 much of the iodine became trapped, likely in microscopic bubbles. True thermal diffusion coefficients for iodine in polycrystalline U02 have been derived by modelling the low-fluence data. (author)

  9. Study of liquid hydrocarbons subjected to ionizing radiations

    International Nuclear Information System (INIS)

    This work is a study of liquid hydrocarbons (especially alkanes and cycloalkanes), ionized and excited by low L.E.T. high energy radiation. An analysis of radiolytical products shows a definite correlation between radiochemical yields and bond energies. The study of the influence of scavengers has been carried out and the methods for the determination of ? parameters are discussed. Ionic recombination has been fully investigated: theoretical studies, based on a phenomenological model, on primary and (in presence of solute) secondary charge recombination have been performed. Secondary species were observed by use of kinetic optical absorption spectrophotometry. A good agreement with theory is obtained only when the electron scavenging before thermalization is negligible. Electron mobility in hydrocarbons has been measured and the electron scavenging rate constants have been determined using the pulse conductivity technique. Conformational analysis calculations show a correlation between the electron mobility and the electronic structure. The rate of formation of a radiolytic product and the rate of decay of its precursor have been studied for solutions of hydrocarbons and electron scavengers

  10. Hydrocarbon removal with constructed wetlands

    OpenAIRE

    Eke, Paul Emeka

    2008-01-01

    Wetlands have long played a significant role as natural purification systems, and have been effectively used to treat domestic, agricultural and industrial wastewater. However, very little is known about the biochemical processes involved, and the use of constructed treatment wetlands in the removal of petroleum aromatic hydrocarbons from produced and/or processed water. Wastewaters from the oil industry contain aromatic hydrocarbons such as benzene, toluene, ethylbenzene and x...

  11. Kinetic mechanisms for Hydrocarbon Ignition

    OpenAIRE

    Bikas, Georgios

    2001-01-01

    The origins of detailed and reduced kinetic models for the ignition and oxidation of alkanes and aromatic hydrocarbons have been traced in this study and their development and application in the prediction of some aspects of hydrocarbon fuels have been explored. The scope and limitations for the application of certain formal model structures has been illustrated. The major objective in development and use of kinetic models has been concerned with autoignition and homogeneous combustion as a p...

  12. Bioassay of polycyclic aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Van Kirk, E.A.

    1980-08-01

    A positive relationship was found between the photodynamic activity of 24 polycyclic aromatic hydrocarbons versus published results on the mutagenicity, carcinogenicity, and initiation of unscheduled DNA synthesis. Metabolic activation of benzo(a)pyrene resulted in detection of increased mutagenesis in Paramecium tetraurelia as found also in the Ames Salmonella assay. The utility of P. tetraurelia as a biological detector of hazardous polycyclic aromatic hydrocarbons is discussed.

  13. Globalization, Migration and Development

    Directory of Open Access Journals (Sweden)

    George, Susan

    2002-01-01

    Full Text Available EnglishMigration may become the most important branch of demography in the earlydecades of the new millennium in a rapidly globalizing world. This paper discusses the causes, costsand benefits of international migration to countries of the South and North, and key issues of commonconcern. International migration is as old as national boundaries, though its nature, volume,direction, causes and consequences have changed. The causes of migration are rooted in the rate ofpopulation growth and the proportion of youth in the population, their education and training,employment opportunities, income differentials in society, communication and transportationfacilities, political freedom and human rights and level of urbanization. Migration benefits the Souththrough remittances of migrants, improves the economic welfare of the population (particularly womenof South countries generally, increases investment, and leads to structural changes in the economy.However, emigration from the South has costs too, be they social or caused by factors such as braindrain. The North also benefits by migration through enhancement of economic growth, development ofnatural resources, improved employment prospects, social development and through exposure toimmigrants' new cultures and lifestyles. Migration also has costs to the North such as of immigrantintegration, a certain amount of destabilization of the economy, illegal immigration, and socialproblems of discrimination and exploitation. Issues common to both North and South include impact onprivate investment, trade, international cooperation, and sustainable development. Both North andSouth face a dilemma in seeking an appropriate balance between importing South's labour or itsproducts and exporting capital and technology from the North.FrenchLa migration est sans doute devenue la partie la plus importante de la démographie des premières décennies du nouveau millénaire dans un monde qui change rapidement. Ce document porte sur les causes, les coûts et les avantages de la migration internationale vers les pays du Sud et du Nord ainsi que sur les grandes préoccupations communes. La migration internationale existe depuis l'avènement des frontières nationales, bien que sa nature, son volume, sa direction ainsi que ses causes et conséquences aient changé. Les causes de la migration trouvent leur origine dans le taux de croissance d'une population, sa proportion de jeunes, leur niveau d'éducation et de formation, les occasions d'emploi, les écarts de revenu dans la société, les systèmes de communication et de transport, la liberté politique, les droits de la personne et le niveau d'urbanisation. La migration profite au Sud parce que les migrants envoient de l'argent, améliorant généralement le bien-être économique de la population (surtout celui des femmes des pays du Sud, augmentant les investissements et donne lieu à des changements structuraux de l'économie. Cependant, l'émigration du Sud a tout de même un prix, que ce soit social ou causé par des facteurs tels que l'exode des cerveaux. Le Nord profite aussi de la migration grâce à une meilleure croissance économique, l'exploitation de richesses naturelles, de meilleures possibilités d'emploi et le développement social par l'exposition aux nouvelles cultures et styles de vie des immigrants. La migration a aussi un prix pour le Nord tel que l'intégration des immigrants, une certaine déstabilisation de l'économie, l'immigration illégale ainsi que les problèmes sociaux relatifs à la discrimination et à l'exploitation. Les préoccupations communes au Sud et au Nord incluent les incidences sur les investissements privés, le commerce, la coopération internationale et le développement durable. Autant le Nord que le Sud doivent composer avec le dilemme de trouver l'équilibre entre l'importation de la main-d'œuvre du Sud.

  14. Maritime hydrocarbon pollution: Intervention

    International Nuclear Information System (INIS)

    The possibility of oil spills is of great concern to Canada because of the large quantities of petroleum that are shipped along its long coastline, the economic importance of fishing and other industries that could be affected by an oil spill, and the severity of climatic conditions in Canadian waters. Measures implemented to handle oil spill emergencies include relevant provisions in the merchant marine laws, establishment of a compensation fund for oil spill cleanup and damage, and provision of oil spill-related services by the Canadian Coast Guard (CCG), whose activities in this regard are summarized. The CCG has a fleet of 119 ships, 4 hydrofoils, 35 helicopters, and various small craft as well as oil spill pollution cleanup equipment worth $35 million stationed at 55 locations across Canada and staff specialists in oil spill emergencies. The CCG is responsible for enforcing the merchant marine law and has created a service for intervening in maritime emergencies. The CCG's equipment includes units for pumping out tankers in an emergency situation, shoreline cleanup devices, skimmers, containment booms, and facilities for adding dispersants to spills. A description of the behavior of hydrocarbons in an oil spill at sea is also included. 26 figs

  15. HYDROCARBONS RESERVES IN VENEZUELA

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez Cruz, D.J.

    2007-07-01

    Venezuela is an important player in the energy world, because of its hydrocarbons reserves. The process for calculating oil and associated gas reserves is described bearing in mind that 90% of the gas reserves of Venezuela are associated to oil. Likewise, an analysis is made of the oil reserves figures from 1975 to 2003. Reference is also made to inconsistencies found by international experts and the explanations offered in this respect by the Ministry of Energy and Petroleum (MENPET) and Petroleos de Venezuela (PDVSA) regarding the changes that took place in the 1980s. In turn, Hubbert's Law is explained to determine peak production of conventional oil that a reservoir or field will reach, as well as its relationship with remaining reserves. Emphasis is placed on the interest of the United Nations on this topic. The reserves of associated gas are presented along with their relationship with the different crude oils that are produced and with injected gas, as well as with respect to the possible changes that would take place in the latter if oil reserves are revised. Some recommendations are submitted so that the MENPET starts preparing the pertinent policies ruling reserves. (auth)

  16. Evaluation of hydrocarbon potential

    Energy Technology Data Exchange (ETDEWEB)

    Cashman, P.H.; Trexler, J.H. Jr. [Univ. of Nevada, Reno, NV (United States)

    1992-09-30

    Task 8 is responsible for assessing the hydrocarbon potential of the Yucca Mountain vincinity. Our main focus is source rock stratigraphy in the NTS area in southern Nevada. (In addition, Trexler continues to work on a parallel study of source rock stratigraphy in the oil-producing region of east central Nevada, but this work is not funded by Task 8.) As a supplement to the stratigraphic studies, we are studying the geometry and kinematics of deformation at NTS, particularly as these pertain to reconstructing Paleozoic stratigraphy and to predicting the nature of the Late Paleozoic rocks under Yucca Mountain. Our stratigraphic studies continue to support the interpretation that rocks mapped as the {open_quotes}Eleana Formation{close_quotes} are in fact parts of two different Mississippian units. We have made significant progress in determining the basin histories of both units. These place important constraints on regional paleogeographic and tectonic reconstructions. In addition to continued work on the Eleana, we plan to look at the overlying Tippipah Limestone. Preliminary TOC and maturation data indicate that this may be another potential source rock.

  17. Diesel-related hydrocarbons can dominate gas phase reactive carbon in megacities

    Directory of Open Access Journals (Sweden)

    R. E. Dunmore

    2015-03-01

    Full Text Available Hydrocarbons are key precursors to two priority air pollutants, ozone and particulate matter. Those with two to seven carbons have historically been straightforward to observe and have been successfully reduced in many developed cities through air quality policy interventions. Longer chain hydrocarbons released from diesel vehicles are not considered explicitly as part of air quality strategies and there are few direct measurements of their gaseous abundance in the atmosphere. This study describes the chemically comprehensive and continuous measurements of organic compounds in a developed megacity (London, which demonstrate that on a seasonal median basis, diesel-related hydrocarbons represent only 20–30% of the total hydrocarbon mixing ratio but comprise more than 50% of the atmospheric hydrocarbon mass and are a dominant local source of secondary organic aerosols. This study shows for the first time that, 60% of the winter primary hydrocarbon hydroxyl radical reactivity is from diesel-related hydrocarbons and using the maximum incremental reactivity scale, we predict that they contribute up to 50% of the ozone production potential in London. Comparing real-world urban composition with regulatory emissions inventories in the UK and US highlights a previously unaccounted for but, very significant under-reporting of diesel related hydrocarbons; an underestimation of a factor ~ 4 for C9 species rising to a factor of over 70 for C12 during winter. These observations show that hydrocarbons from diesel vehicles can dominate gas phase reactive carbon in cities with high diesel fleet fractions. Future control of urban particulate matter and ozone in such locations requires a shift in policy focus onto gas phase hydrocarbons released from diesels as this vehicle type continues to displace gasoline world-wide.

  18. Diesel-related hydrocarbons can dominate gas phase reactive carbon in megacities

    Science.gov (United States)

    Dunmore, R. E.; Hopkins, J. R.; Lidster, R. T.; Lee, J. D.; Evans, M. J.; Rickard, A. R.; Lewis, A. C.; Hamilton, J. F.

    2015-03-01

    Hydrocarbons are key precursors to two priority air pollutants, ozone and particulate matter. Those with two to seven carbons have historically been straightforward to observe and have been successfully reduced in many developed cities through air quality policy interventions. Longer chain hydrocarbons released from diesel vehicles are not considered explicitly as part of air quality strategies and there are few direct measurements of their gaseous abundance in the atmosphere. This study describes the chemically comprehensive and continuous measurements of organic compounds in a developed megacity (London), which demonstrate that on a seasonal median basis, diesel-related hydrocarbons represent only 20-30% of the total hydrocarbon mixing ratio but comprise more than 50% of the atmospheric hydrocarbon mass and are a dominant local source of secondary organic aerosols. This study shows for the first time that, 60% of the winter primary hydrocarbon hydroxyl radical reactivity is from diesel-related hydrocarbons and using the maximum incremental reactivity scale, we predict that they contribute up to 50% of the ozone production potential in London. Comparing real-world urban composition with regulatory emissions inventories in the UK and US highlights a previously unaccounted for but, very significant under-reporting of diesel related hydrocarbons; an underestimation of a factor ~ 4 for C9 species rising to a factor of over 70 for C12 during winter. These observations show that hydrocarbons from diesel vehicles can dominate gas phase reactive carbon in cities with high diesel fleet fractions. Future control of urban particulate matter and ozone in such locations requires a shift in policy focus onto gas phase hydrocarbons released from diesels as this vehicle type continues to displace gasoline world-wide.

  19. Suicidal Ideation and Migration Aspirations among Youth in Central Mexico

    Directory of Open Access Journals (Sweden)

    Steven Hoffman

    2013-09-01

    Full Text Available Over the past 100 years the state of Guanajuato has consistently been one of the highest migrant sending states in Mexico. Youth living in high migratory states such as Guanajuato are heavily influenced by the expectation that they will travel to the US, and research has shown that those who do not migrate may be looked down upon by members of their community. This secondary analysis looks at the connection between suicidal ideation and migration aspirations among a group of adolescents living in Guanajuato, Mexico. Data were originally collected in 2007 as part of a comprehensive health survey of youth attending an alternative high schooling program. Regression analyses show that suicidal ideation predicts intentions to migrate among both males and females, while other factors differentially influence the adolescents by gender. The results indicate that suicidal ideation may be associated with migration aspirations among Mexican youth living in high migratory communities. Study limitations and implications are discussed.

  20. Biometrics and international migration.

    Science.gov (United States)

    Redpath, Jillyanne

    2007-01-01

    This paper will focus on the impact of the rapid expansion in the use of biometric systems in migration management on the rights of individuals; it seeks to highlight legal issues for consideration in implementing such systems, taking as the starting point that the security interests of the state and the rights of the individual are not, and should not be, mutually exclusive. The first part of this paper briefly describes the type of biometric applications available, how biometric systems function, and those used in migration management. The second part examines the potential offered by biometrics for greater security in migration management, and focuses on developments in the use of biometrics as a result of September 11. The third part discusses the impact of the use of biometrics in the management of migration on the individual's right to privacy and ability to move freely and lawfully. The paper highlights the increasing need for domestic and international frameworks to govern the use of biometric applications in the migration/security context, and proposes a number of issues that such frameworks could address. PMID:17536151

  1. 21 CFR 178.3530 - Isoparaffinic petroleum hydrocarbons, synthetic.

    Science.gov (United States)

    2010-04-01

    ...2009-04-01 true Isoparaffinic petroleum hydrocarbons, synthetic. 178.3530 Section...Aids § 178.3530 Isoparaffinic petroleum hydrocarbons, synthetic. Isoparaffinic petroleum hydrocarbons, synthetic, may be...

  2. 21 CFR 172.882 - Synthetic isoparaffinic petroleum hydrocarbons.

    Science.gov (United States)

    2010-04-01

    ... true Synthetic isoparaffinic petroleum hydrocarbons. 172.882 Section 172.882...172.882 Synthetic isoparaffinic petroleum hydrocarbons. Synthetic isoparaffinic petroleum hydrocarbons may be safely used in food,...

  3. Secondary Current and Classification of River Channels

    Directory of Open Access Journals (Sweden)

    Kaguchwa John Njenga

    2013-01-01

    Full Text Available In this research, the secondary current theory is used in investigating the role of phase shift angle between the secondary current and the channel axis displacement in stability analysis of a river channel. To achieve this, a small-perturbation stability analysis is developed for investigation of the role of the secondary current accompanying channel curvature in the initiation and early development of meanders in open channels. The secondary currents are generating in planes perpendicular to the primary direction of motion. The secondary currents form a helical motion in which the water in the upper part of the river is driven outward, whereas the water near the bottom is driven inward in a bend. Force-momentum equations for longitudinal and transverse direction in open channel bends were utilized. Assuming that the transverse force contributed by the bed is negligible, the pressure force associated with the transverse surface inclination is balanced by the centripetal force. Existing equations of the transverse velocity profile were analyzed. Since the magnitude of the vertical velocity is negligible compared to the transverse velocity in secondary currents, this study concentrates on the transverse velocity which is the radial component of the secondary current. This formulation leads to a linear differential equation which is solved for its orthogonal components which give the rates of meander growth and downstream migration. It is shown that instability increases with decrease in phase shift angle. Transition from straight to meandering and then from meandering to braiding occurs when phase shift angle is reduced.

  4. The Analysis of International Migration towards Economic Growth

    Directory of Open Access Journals (Sweden)

    Ferdous Alam

    2011-01-01

    Full Text Available Problem statement: This study discusses the analysis of international migration towards economic growth in Bangladesh. International migration refers to the cross-border movement of people from a mother country to a location outside that mother country, with the purpose of taking up higher income employment, better living conditions, higher education get access to civic amenities and conducting a daily existence there for an extended period of time. The exports of labor, human capital, play a major role to minimize the poverty level in Bangladesh. In the last four decades, Bangladesh exports the huge number of labors abroad for economic growth through remittances. Remittances affect poverty eradication most directly by increasing the income of households which have a family member working abroad. Because income from remittances is usually larger than that which could have been earned by migrants they stayed at home. Approach: The aim of this study is to highlight the policy implications for the maximization of international migration and the analysis of economic growth in Bangladesh. The data for analysis is perceived from the secondary sources. The significant manipulations for acquired data are migration of employment and remittances for economic growth in Bangladesh. Results: Migration contributed for the development of macro and micro level in Bangladesh. Conclusion: There would be potential benefits to world's poor if more international attention were focused on integrating migration policy to within the larger global dialogue economic development and poverty reduction. Strong institutions and good policies will enhance the benefits of human capital migration for Bangladesh.

  5. An urban aquifer and the presence of petroleum hydrocarbons

    International Nuclear Information System (INIS)

    Fredericton, New Brunswick gets most of its water supply from a glaciofluvial sand and gravel aquifer located beneath the downtown area. The near-surface accidental release of petroleum hydrocarbons above the aquifer and above discontinuities in the overlying aquitard has necessitated implementation of remedial measures at several locations. Three case studies are reviewed. At the Smythe Street School, ca 5,500 liters of heating oil were found to have leaked from a basement tank, penetrating into the underlying soil through cracks in the basement slab. Remedial measures included drilling an intercept well, soil venting, and bioremediation. Except for early peaks, fuel oil concentrations have not been detected in the recovery well or site monitoring wells. At a gasoline distributor, ca 1,000 liters of gasoline was released from a leaky underground tank. All tanks and 340 tonnes of soil were removed. A pump and treat system provided containment of the dissolved plume, which migrated within the shallow water table aquifer above the aquitard. At an office complex, over 36,000 liters of bunker C and fuel oil has been recovered from pumping activities after ground contamination was discovered during an underground tank replacement program. The viscous nature of the hydrocarbons means that the contaminants are mainly immobile, but low levels of hydrocarbons have been detected at monitoring wells downgradient of the site. The three cases studied do not pose a threat to the quses studied do not pose a threat to the quality of the Fredericton water supply. 6 refs., 2 figs

  6. Hydrocarbon exploration risk evaluation through uncertainty and sensitivity analyses techniques

    International Nuclear Information System (INIS)

    The evaluation of the exploration risk in the oil industry is a fundamental component of the decision process related to the exploratory phase. In this paper the two basic components of the exploratory risk: trap geometry and trapped hydrocarbon quantities (fluid), are compounded in a single coherent uncertainty and sensitivity approach. The results clarify that the model geometry influences each Petroleum System Modeling step and that the geometric uncertainty is correlated with the fluid uncertainty. The geometric uncertainty evaluation makes use of geostatistical techniques that produce a number of possible realizations of the trap geometry, all compatible with available data. The evaluation of the fluid uncertainty, through a Monte Carlo methodology, allows us to compute the possible quantities of oil and gas, generated in a basin and migrated from the hydrocarbon source location to each single trap. The final result is the probability distribution of oil and gas for each trap in the basin, together with other useful indicators like: the hydrocarbon filling probability map, the closure probability map, the drainage area probability map, the spilling paths probabilities, the trap-filling scenarios

  7. Polycyclic Aromatic Hydrocarbons

    Science.gov (United States)

    Salama, Farid

    2010-01-01

    Carbonaceous materials play an important role in space. Polycyclic Aromatic Hydrocarbons (PAHs) are a ubiquitous component of the carbonaceous materials. PAHs are the best-known candidates to account for the IR emission bands. They are also thought to be among the carriers of the diffuse interstellar absorption bands (DIBs). PAH ionization states reflect the ionization balance of the medium while PAH size, composition, and structure reflect the energetic and chemical history of the medium. A major challenge is to reproduce in the laboratory the physical conditions that exist in the emission and absorption interstellar zones. The harsh physical conditions of the ISM -low temperature, collisionless, strong UV radiation fields- are simulated in the laboratory by associating a molecular beam with an ionizing discharge to generate a cold plasma expansion. PAH ions and radicals are formed from the neutral precursors in an isolated environment at low temperature and probed with high-sensitivity cavity ringdown spectroscopy in the NUV-NIR range. Carbon nanoparticles are also formed during the short residence time of the precursors in the plasma and are characterized with time-offlight mass spectrometry. These experiments provide unique information on the spectra of large carbonaceous molecules and ions in the gas phase that can now be directly compared to interstellar and circumstellar observations (IR emission bands, DIBs, extinction curve). These findings also hold great potential for understanding the formation process of interstellar carbonaceous grains. We will review recent progress in the experimental and theoretical studies of PAHs, compare the laboratory data with astronomical observations and discuss the global implications.

  8. Evidence of primary migration of condensate by molecular solution in aqueous phase in Yacheng Field, offshore South China

    Science.gov (United States)

    Quanxing, Zhang; Qiming, Zhang

    The composition of Yacheng condensate provides possible evidences of primary migration of petroleum by molecular solution in the aqueous phase. Aromatic hydrocarbons (HCs), especially benzene and toluene, make up a high percentage of the condensate. The abundance of each hydrocarbon (HC) in the condensate is mainly controlled by compound type and carbon number. The distribution of normal alkanes is discontinuous at C 16. Aromatic hydrocarbons are 3.8‰ isotopically heavier than the saturated hydrocarbons. The isoprenoid hydrocarbons are very abundant, especially pristane. The specific gravity of the Yacheng condensate is 0.85530 g cm -3, which is much higher than the average for condensates. These features are in good agreement with the HC solubilities in aqueous solution.

  9. Migration Information Source

    Science.gov (United States)

    As a publication of the Migration Policy Institute, the Migration Information Source "provides fresh thought, authoritative data from numerous global organizations and governments, and global analysis of international migration and refugee trends." Their well-organized homepage offers policy briefs, "Spotlight" features (including a recent one on Indian immigrants in the United States), and information about their ongoing projects. Policy makers and scholars will love the "Immigration Data Hub" area. Here they can get valuable data on state responses to immigrations, the top global destinations for Irish immigrants, as well as historical immigration data. Visitors can also use the "US in Focus" area to find out about specific immigration trends throughout the country, with a special focus on policy issues affecting states and urban areas. The site is rounded out by an RSS feed, a press room of recent news releases, and a glossary of terms.

  10. Hydrocarbon charge modeling, Balingian Province, Sarawak, Malaysia

    Energy Technology Data Exchange (ETDEWEB)

    Swinburn, P. (Sarawak Shell Berhad (Malaysia)); Burgisser, H. (KSEPL, Rijswijk (Netherlands)); Yassin, J. (Petronas Carigali, Kuala Lumpur (Malaysia))

    1994-07-01

    Generation, expulsion, and migration of oil and gas from Tertiary coal beds was modeled for a 2700 km[sup 2] area offshore Sarawak with Shell's integrated basin modeling software. The modeling was undertaken in response to the difficulty of predicting gas:oil, particularly in recent exploration wells. In the Balingian Province, oil and gas are produced from Miocene coastal plain clastics. Although all the hydrocarbons are thought to be sourced from the same type of land plant source rock, the gas:oil ratio varies considerably among the three producing fields and several undeveloped discoveries. Geochemical analyses of source-rock samples and oils strongly indicate that oils in the Balingian Province are sourced by coals and coaly shales found in the Oligocene and early Miocene coastal plain sequences. For these source rocks the main phase of oil generation is in the maturity range 0.8-1.1% VR equivalent. The burial history is well constrained by mapping regionally dated horizons and erosional surfaces. The temperature history suggests that from the late Oligocene to present, the heat flow was basically constant and fairly high due to sustained wrenching.

  11. Migration scenarii in extrasolar systems

    Directory of Open Access Journals (Sweden)

    Crida A.

    2011-02-01

    Full Text Available In this review talk, I present the theory of type I migration of small mass planets, and its latest developments that open the possibility of outward migration in the inner part of a protoplanetary disk. I also review the type II migration of giant planets, and mention the runaway, type III. Then, we focus on the migration of pairs of planets in resonance. The eccentricity of the planets raise, and possibly their mutual inclination as well. Also, the migration rate can be changed, and directed outward if the outer planet is the lighter. Last, we present a synthetic scenario of migration for the giant planets of our Solar System.

  12. Migration of seismic data

    International Nuclear Information System (INIS)

    Prospecting for oil and gas resources poses the problem of determining the geological structure of the earth's crust from indirect measurements. Seismic migration is an acoustic image reconstruction technique based on the inversion of the scalar wave equation. Extensive computation is necessary before reliable information can be extracted form large sets of recorded data. In this paper a collection of open-quotes industrialclose quotes migration techniques, each giving rise to a data parallel algorithm, is outlined. Computer simulations on synthetic seismic data illustrate the problem and the approach

  13. Is Migration Feminized?

    OpenAIRE

    Tokso?z, Gu?lay

    2012-01-01

    In the context of Turkey’s accession to the EU, the issue of potential migration from Turkey and its impact upon European labor markets became one of the concerns of the EU, considering Turkey’s growing population and young labor force. In 2011, half a century after the bi-lateral agreement between Turkey and Germany on labor recruitment in 1961, migration plays a key role in relations of Turkey with the EU and will even increase its significance – not necessarily for the next fifty ye...

  14. Migration, klima og sundhed

    DEFF Research Database (Denmark)

    Tellier, Siri; Carballo, Manuel

    2009-01-01

    Many tentative connections have been postulated between migration and climate. This article points to rural-urban migration, particularly into low elevation urban slums prone to flooding as an issue needing urgent attention by health professionals. It also notes the no-man's land in which environmental refugees find themselves and the consequences this may have. Finally, it points to the urgent need to reform health systems in both developing and developed countries to adapt to rapidly changing disease patterns and to become more responsive to them. Udgivelsesdato: 2009-Oct-26

  15. Unix Application Migration Guide

    CERN Document Server

    Microsoft. Redmond

    2003-01-01

    Drawing on the experience of Microsoft consultants working in the field, as well as external organizations that have migrated from UNIX to Microsoft® Windows®, this guide offers practical, prescriptive guidance on the issues you are likely to face when porting existing UNIX applications to the Windows operating system environment. Senior IT decision makers, network managers, and operations managers will get real-world guidance and best practices on planning and implementation issues to understand the different methods through which migration or co-existence can be accomplished. Also detailing

  16. What's driving migration?

    Science.gov (United States)

    Kane, H

    1995-01-01

    During the 1990s investment in prevention of international or internal migration declined, and crisis intervention increased. The budgets of the UN High Commissioner for Refugees and the UN Development Program remained about the same. The operating assumption is that war, persecution, famine, and environmental and social disintegration are inevitable. Future efforts should be directed to stabilizing populations through investment in sanitation, public health, preventive medicine, land tenure, environmental protection, and literacy. Forces pushing migration are likely to increase in the future. Forces include depletion of natural resources, income disparities, population pressure, and political disruption. The causes of migration are not constant. In the past, migration occurred during conquests, settlement, intermarriage, or religious conversion and was a collective movement. Current migration involves mass movement of individuals and the struggle to survive. There is new pressure to leave poor squatter settlements and the scarcities in land, water, and food. The slave trade between the 1500s and the 1800s linked continents, and only 2-3 million voluntarily crossed national borders. Involuntary migration began in the early 1800s when European feudal systems were in a decline, and people sought freedom. Official refugees, who satisfy the strict 1951 UN definition, increased from 15 million in 1980 to 23 million in 1990 but remained a small proportion of international migrants. Much of the mass movement occurs between developing countries. Migration to developed countries is accompanied by growing intolerance, which is misinformed. China practices a form of "population transfer" in Tibet in order to dilute Tibetan nationalism. Colonization of countries is a new less expensive form of control over territory. Eviction of minorities is another popular strategy in Iraq. Public works projects supported by foreign aid displace millions annually. War and civil conflicts have increased since the 1950s from 10 to 34. Of the 82 armed conflicts between 1988 and 1992, only 3 were between countries. Journalist Robert Kaplan suggests that future instability will occur due to heightened crime and fragmentation of government systems. The African continent has experienced very high migration. PMID:12288448

  17. Hydrocarbons as markers for identifying postirradiated peanuts

    International Nuclear Information System (INIS)

    Hydrocarbons produced by ?-radiation of peanuts were analyzed to determine the relationship between irradiation and production of hydrocarbons, and the use of hydrocarbons as markers for identifying postirradiated peanuts. Hydrocarbons in peanuts were determined by a sequential procedure of lipid extraction by hexane, Florisil column chromatography, and gas chromatography. Hydrocarbons C17:1, C16:2, C17:2, and C16:3 were easily detected in peanuts irradiated at 0.5 kGy or higher, but not in unirradiated ones. The hydrocarbons were minimally changed by roasting the irradiated peanuts and were not detected in unirradiated roasted peanuts

  18. The International Organization for Migration in Global Migration Governance

    OpenAIRE

    Poulsen, Sofie Havn; Andersen, Lise

    2011-01-01

    This project focuses on the IOM, the notion of global governance of migration and the interaction between these two. The point of departure has been an attempt to grasp the current global approach to migration and comprehend whether, or to what degree, there is governance of migration issues taking place at a global level.

  19. Practical Data Migration

    CERN Document Server

    Morris, Johny

    2012-01-01

    This book is for executives and practitioners tasked with the movement of data from old systems to a new repository. It uses a series of steps guaranteed to get the reader from an empty new system to one that is working and backed by the user population. Using this proven methodology will vastly increase the chances of a successful migration.

  20. Net Migration Statistics

    Science.gov (United States)

    Bar chart of countries ranked by their net migration flow as of 2005. While the highest net in-flow is generally into large rich countries (USA, Spain, Germany etc.) Afghanistan had the second highest net inflow thanks to returning refugees.

  1. Migration pathways in soils

    International Nuclear Information System (INIS)

    This study looked at diffusive migration through three types of deformation; the projectile pathways, hydraulic fractures of the sediments and faults, and was divided into three experimental areas: autoradiography, the determination of diffusion coefficients and electron microscopy of model projectile pathways in clay. For the autoradiography, unstressed samples were exposed to two separate isotopes, Pm-147 (a possible model for Am behaviour) and the poorly sorbed iodide-125. The results indicated that there was no enhanced migration through deformed kaolin samples nor through fractured Great Meteor East (GME) sediment, although some was evident through the projectile pathways in GME and possibly through the GME sheared samples. The scanning electron microscopy of projectile pathways in clay showed that emplacement of a projectile appeared to have no effect on the orientation of particles at distances greater than two projectile radii from the centre of a projectile pathway. It showed that the particles were not simply aligned with the direction of motion of the projectile but that, the closer to the surface of a particular pathway, the closer the particles lay to their original orientation. This finding was of interest from two points of view: i) the ease of migration of a pollutant along the pathway, and ii) possible mechanisms of hole closure. It was concluded that, provided that there is no advective migration, the transport of radionuclides through sediments containing these defects would not be significantly more rapid than in undeformed sediments. (author)

  2. International Migration of Couples

    DEFF Research Database (Denmark)

    Munk, Martin D.; Junge, Martin

    2015-01-01

    We analyze emigration and return decisions of Danish couples. Our main questions are how emigration and return migration decisions depend on education, earnings, and the number and age of children. We use register data on full population from 1982 to 2006, focusing on opposite-gender couples in which the female is aged 23 to 37, and the male 25 to 39. We find that power couples in which both are highly educated are most likely to emigrate, but also most likely to return. Couples in which only the male is highly educated are more than twice as likely to emigrate as if only the female is highly edu-cated. Couples in which neither partner is highly educated are least likely to emigrate, but also have lowest return migration rates. This suggests that migration as brain circu-lation is most pronounced among the highly-educated. The probability of emigration is increasing in male earnings, but does not depend much on female earnings. Having children reduces the likelihood of emigration and the more so the older children are. Surprisingly, the return rates do not depend much on the number of children. Overall, our findings suggest that family migration patterns are still surprisingly traditional, re-sponding more to the male's job opportunities and education.

  3. Mexican Migration Project

    Science.gov (United States)

    The Mexican Migration Project's (MMP) interdisciplinary team of researchers collects and analyzes social and economic information on "the complex process of Mexican migration to the United States." This bilingual Website makes the project's work publicly available for research and education. Included are background information about the MMP, Facts & Figures on migration, and a section entitled Expressions, which provides oral histories and online artistic exhibits to promote an "understand[ing of] the emotional reality of migration." However, the core of the site is the extensive MMP Database, which contains general demographic and migratory data on over 7,000 households surveyed in 52 Mexican communities and data on more than 500 households surveyed in the US. Unix and PC Users may download the compressed (.zip) MMP data files in either ASCII (.dat) or SPSS portable (.exp) formats. Corresponding technical documentation is also available in .pdf format. The MMP is a binational research initiative co-directed by Jorge Durand, Professor of Social Anthropology at the University of Guadalajara, and Douglas S. Massey, Professor of Demography and Sociology at the University of Pennsylvania.

  4. Primary and Secondary Sources

    Science.gov (United States)

    Albion Middle School Library--Mrs. Bates

    2010-01-23

    Use these links to learn more about primary and secondary sources. 1. Explore the links below to learn about primary and secondary sources. When you have finished, you should be able to: Tell the difference between primary and secondary sources. Give at least three examples of primary sources and three examples of secondary sources. Explain why primary sources are important in research. Examples of Primary Sources Examples of Primary and Secondary Sources on the Same Topic Genres/Formats of Primary Sources 2. ...

  5. Biological enhancement of hydrocarbon extraction

    Science.gov (United States)

    Brigmon, Robin L. (North Augusta, SC); Berry, Christopher J. (Aiken, SC)

    2009-01-06

    A method of microbial enhanced oil recovery for recovering oil from an oil-bearing rock formation is provided. The methodology uses a consortium of bacteria including a mixture of surfactant producing bacteria and non-surfactant enzyme producing bacteria which may release hydrocarbons from bitumen containing sands. The described bioprocess can work with existing petroleum recovery protocols. The consortium microorganisms are also useful for treatment of above oil sands, ground waste tailings, subsurface oil recovery, and similar materials to enhance remediation and/or recovery of additional hydrocarbons from the materials.

  6. Total Petroleum Hydrocarbons (TPH): ToxFAQs

    Science.gov (United States)

    ... a state: This map displays locations where Total Petroleum Hydrocarbons (TPH) is known to be present. On This ... I get more information? ToxFAQs TM for Total Petroleum Hydrocarbons (TPH) ( Hidrocarburos Totales de Petróleo (TPH) ) August 1999 ...

  7. Ambient aromatic hydrocarbon measurements at Welgegund, South Africa

    Science.gov (United States)

    Jaars, K.; Beukes, J. P.; van Zyl, P. G.; Venter, A. D.; Josipovic, M.; Pienaar, J. J.; Vakkari, V.; Aaltonen, H.; Laakso, H.; Kulmala, M.; Tiitta, P.; Guenther, A.; Hellén, H.; Laakso, L.; Hakola, H.

    2014-07-01

    Aromatic hydrocarbons are associated with direct adverse human health effects and can have negative impacts on ecosystems due to their toxicity, as well as indirect negative effects through the formation of tropospheric ozone and secondary organic aerosol, which affect human health, crop production and regional climate. Measurements of aromatic hydrocarbons were conducted at the Welgegund measurement station (South Africa), which is considered to be a regionally representative background site. However, the site is occasionally impacted by plumes from major anthropogenic source regions in the interior of South Africa, which include the western Bushveld Igneous Complex (e.g. platinum, base metal and ferrochrome smelters), the eastern Bushveld Igneous Complex (platinum and ferrochrome smelters), the Johannesburg-Pretoria metropolitan conurbation (> 10 million people), the Vaal Triangle (e.g. petrochemical and pyrometallurgical industries), the Mpumalanga Highveld (e.g. coal-fired power plants and petrochemical industry) and also a region of anticyclonic recirculation of air mass over the interior of South Africa. The aromatic hydrocarbon measurements were conducted with an automated sampler on Tenax-TA and Carbopack-B adsorbent tubes with heated inlet for 1 year. Samples were collected twice a week for 2 h during daytime and 2 h during night-time. A thermal desorption unit, connected to a gas chromatograph and a mass selective detector was used for sample preparation and analysis. Results indicated that the monthly median (mean) total aromatic hydrocarbon concentrations ranged between 0.01 (0.011) and 3.1 (3.2) ppb. Benzene levels did not exceed the local air quality standard limit, i.e. annual mean of 1.6 ppb. Toluene was the most abundant compound, with an annual median (mean) concentration of 0.63 (0.89) ppb. No statistically significant differences in the concentrations measured during daytime and night-time were found, and no distinct seasonal patterns were observed. Air mass back trajectory analysis indicated that the lack of seasonal cycles could be attributed to patterns determining the origin of the air masses sampled. Aromatic hydrocarbon concentrations were in general significantly higher in air masses that passed over anthropogenically impacted regions. Inter-compound correlations and ratios gave some indications of the possible sources of the different aromatic hydrocarbons in the source regions defined in the paper. The highest contribution of aromatic hydrocarbon concentrations to ozone formation potential was also observed in plumes passing over anthropogenically impacted regions.

  8. Towards an understanding of the role of clay minerals in crude oil formation, migration and accumulation

    Science.gov (United States)

    Wu, Lin Mei; Zhou, Chun Hui; Keeling, John; Tong, Dong Shen; Yu, Wei Hua

    2012-12-01

    This article reviews progress in the understanding of the role of clay minerals in crude oil formation, migration and accumulation. Clay minerals are involved in the formation of kerogen, catalytic cracking of kerogen into petroleum hydrocarbon, the migration of crude oil, and the continued change to hydrocarbon composition in underground petroleum reservoirs. In kerogen formation, clay minerals act as catalysts and sorbents to immobilize organic matter through ligand exchange, hydrophobic interactions and cation bridges by the mechanisms of Maillard reactions, polyphenol theory, selective preservation and sorptive protection. Clay minerals also serve as catalysts in acid-catalyzed cracking of kerogen into petroleum hydrocarbon through Lewis and Brønsted acid sites on the clay surface. The amount and type of clay mineral affect the composition of the petroleum. Brønsted acidity of clay minerals is affected by the presence and state of interlayer water, and displacement of this water is a probable driver in crude oil migration from source rocks. During crude oil migration and accumulation in reservoirs, the composition of petroleum is continually modified by interaction with clay minerals. The clays continue to function as sorbents and catalysts even while they are being transformed by diagenetic processes. The detail of chemical interactions and reaction mechanisms between clay minerals and crude oil formation remains to be fully explained but promises to provide insights with broader application, including catalytic conversion of biomass as a source of sustainable energy into the future.

  9. Role of aldehyde chemistry and NOx concentrations in secondary organic aerosol formation

    OpenAIRE

    Wennberg, P O; Flagan, R. C.; Yee, L.D.; Crounse, J. D.; C. L. Loza; Surratt, J.D.; Chhabra, P. S.; A. W. H. Chan; M. N. Chan; Seinfeld, J. H.

    2010-01-01

    Aldehydes are an important class of products from atmospheric oxidation of hydrocarbons. Isoprene (2-methyl-1,3-butadiene), the most abundantly emitted atmospheric non-methane hydrocarbon, produces a significant amount of secondary organic aerosol (SOA) via methacrolein (a C4-unsaturated aldehyde) under urban high-NOx conditions. Previously, we have identified peroxy methacryloyl nitrate (MPAN) as the important intermediate to isoprene and methacrolein SOA in this NOx regime. Here we show tha...

  10. Fluid Inclusions Usage for Assessing Oil Migration in Duhok, North Iraq

    OpenAIRE

    Salih Muhammad Awadh; Bayraktutan, Mehmet S.; Jassim, Sahar Y.; Al-ameri, Thamer K.

    2010-01-01

    Studies of primary and secondary fluid inclusions were done on epigenetic barite samples collected from carbonates of Lower part of Sarmord Formation (Lower Cretaceous) and Aqra-Bekhme Formations (Upper Cretaceous) in Duhok, north Iraq. Lead isotopes composition in galena which associated barite that contained fluid inclusions helped the identification two events of fluid inclusions. These fluid inclusions contain brine water and hydrocarbons. Primary and secondary fluid inclusions in barite ...

  11. Migrations in Slovenian geography textbooks

    Directory of Open Access Journals (Sweden)

    Jurij Senega?nik

    2013-12-01

    Full Text Available In Slovenia, the migrations are treated in almost all geographical textbooks for different levels of education. In the textbooks for the elementary school from the sixth to ninth grade, students acquire knowledge of the migrations by the inductive approach. Difficulty level of treatment and quantity of information are increasing by the age level. In the grammar school program a trail of gaining knowledge on migration is deductive. Most attention is dedicated to migrations in general geography textbooks. The textbooks for vocational and technical school programs deal with migrations to a lesser extent and with different approaches.

  12. Dispersal and migration

    Directory of Open Access Journals (Sweden)

    Schwarz, C.

    2004-06-01

    Full Text Available Ringing of birds unveiled many aspects of avian migration and dispersal movements. However, there is even much more to be explored by the use of ringing and other marks. Dispersal is crucial in understanding the initial phase of migration in migrating birds as it is to understand patterns and processes of distribution and gene flow. So far, the analysis of migration was largely based on analysing spatial and temporal patters of recoveries of ringed birds. However, there are considerable biases and pitfalls in using recoveries due to spatial and temporal variation in reporting probabilities. Novel methods are required for future studies separating the confounding effects of spatial and temporal heterogeneity of recovery data and heterogeneity of the landscape as well. These novel approaches should aim a more intensive and novel use of the existing recovery data by taking advantage of, for instance, dynamic and multistate modeling, should elaborate schemes for future studies, and should also include other marks that allow a more rapid data collection, like telemetry, geolocation and global positioning systems, and chemical and molecular markers. The latter appear to be very useful in the delineating origin of birds and connectivity between breeding and non–breeding grounds. Many studies of migration are purely descriptive. However, King and Brooks (King & Brooks, 2004 examine if movement patterns of dolphins change after the introduction of a gillnet ban. Bayesian methods are an interesting approach to this problem as they provide a meaningful measure of the probability that such a change occurred rather than simple yes/no response that is often the result of classical statistical methods. However, the key difficulty of a general implementation of Bayesian methods is the complexity of the modelling —there is no general userfriendly package that is easily accessible to most scientists. Drake and Alisauskas (Drake & Alisauskas, 2004 examine the philopatric movement of geese using a classic multi–state design. Previous studies of philopaty often rely upon simple return rates —however, good mark–recapture studies do not need to assume equal detection probabilities in space and time. This is likely the most important contribution of multi–state modelling to the study of movement. As with many of these studies, the most pressing problem in the analysis is the explosion in the number of parameters and the need to choose parsimonious modelss to get good precision. Drake and Alisauska demonstrate that model choice still remains an art with a great deal of biological insight being very helpful in the task. There is still plenty of scope for novel methods to study migration. Traditionally, there has been a clear cut distinction between birds being labelled as “migrant” or “resident” on the basis of field observations and qualitative interpretations of patterns of ring–recoveries. However, there are intermediate species where only part of the population migrates (partial migrants or where different components of the population migrate to different extents (differential migrants. Siriwardena, Wernham and Baillie (Siriwardena et al., 2004 develop a novel method that produces a quantitative index of migratory tendency. The method uses distributions of ringing–to–recovery distances to classify individual species’ patterns of movement relative to those of other species. The areas between species’ cumulative distance distributions are used with multi–dimensional scaling to produce a similarity map among species. This map can be used to investigate the factors that affect the migratory strategies that species adopt, such as body size, territoriality and distribution, and in studies of their consequences for demographic parameters such as annual survival and the timing of breeding. The key assumption of the method is the similar recovery effort of species over space and time. It would be interesting to overlay maps of effort to try and remove any induced artefacts in the data. Differences in

  13. Diasporas, Migration & Identities

    Science.gov (United States)

    Funded with substantial monies provided by the Arts and Humanities Research Council in the United Kingdom, the Diasporas, Migrations & Identities research programme is designed "to research, discuss and present issues related to diasporas and migration, and their past and present impact on subjectivity and identity, culture and the imagination, place and space, emotion, politics and sociality." While the programme is no longer actively funded, visitors can view the fruits of their academic labors on this site in the "Publications" area. Visitors to this section can view their annual reports and their working papers. Scholars and others can make their way through ten working papers, which include the titles "Here we go-but where? The possibilities of diaspora in the field of sport" and "London's Chinatown: Diaspora, Identity and Belonging". The site also contains a "Links" area, which contains a healthy selection of external links to other like-minded research institutes and centers.

  14. International Migration and Human Rights

    Science.gov (United States)

    The Global Migration Group (GMG) is an inter-agency group that is dedicated to encouraging the "adoption of more coherent, comprehensive and better coordinated approaches to the issue of international migration." Their number includes representatives from UNICEF, the World Bank and various regional commissions from the United Nations. In October 2008, they released this 144-page report in order to commemorate and reflect on the 60th anniversary of the Universal Declaration of Human Rights. The report is divided into seven sections, including those dealing with the legal framework of migration, globalization and migration trends, migration data, and a concluding chapter which discusses some of the most pressing issues facing different migrant groups around the world. The report also includes three very useful appendices which deal with the policy instruments used in regards to human migration and the adoption of key United Nations legal instruments involved with international migration.

  15. Wetlands and Bird Migration

    Science.gov (United States)

    This activity demonstrates that coastal wetlands are an important factor to insure the success of bird migration. Students will discover that ponds, lakes and marshes provide food and shelter for traveling birds and, without the wetlands, birds would not have the energy to make the trek from areas as far south as Panama. They also learn that besides providing habitats for waterfowl, wetlands help relieve flooding, filter pollutants and are an integral part of the biosphere.

  16. Education, unemployment and migration

    OpenAIRE

    Eggert, Wolfgang; Krieger, Tim; Meier, Volker

    2009-01-01

    This paper studies a two-region model in which unemployment, education decisions and interregional migration are endogenous. The poorer region exhibits both lower wages and higher unemployment rates, and migrants to the richer region are disproportionally skilled. The brain drain from the poor to the rich region is accompanied by stronger incentives to acquire skills even for immobile workers. Regional shocks tend to affect both regions in a symmetric fashion, and skilled-biased technological...

  17. Essays on migration

    OpenAIRE

    Sarvimäki, Matti

    2009-01-01

    This dissertation consists of four empirical essays and an introductory chapter on the economics of migration. The first two essays study the longterm effects of relocating 11% of the Finnish population after the World War II. The first essay suggests that this shock set off a self-reinforcing process, where municipalities receiving the largest flows of displaced persons grew faster also in later periods. The second essay shows that being displaced increased long-term income of men, but had n...

  18. Functorial Data Migration

    CERN Document Server

    Spivak, David I

    2010-01-01

    In this paper we present a simple database definition language: that of categories and functors. A database schema is a category and a state is a set-valued functor. We show that morphisms of schemas induce three "data migration functors" that translate states from one schema to the other in canonical ways. Database states form a boolean topos of which the classical "relational algebra" is a fragment. These ideas thus create a new denotational semantics for database theory.

  19. Functorial Data Migration

    OpenAIRE

    Spivak, David I.

    2010-01-01

    In this paper we present a simple database definition language: that of categories and functors. A database schema is a small category and an instance is a set-valued functor on it. We show that morphisms of schemas induce three "data migration functors", which translate instances from one schema to the other in canonical ways. These functors parameterize projections, unions, and joins over all tables simultaneously and can be used in place of conjunctive and disjunctive que...

  20. Migration of uranium

    International Nuclear Information System (INIS)

    Uranium migration is treated as a process leading to mobilization and concentration of uranium in ore deposits. During the formation of global zonation, uranium migration contributed to the enrichment of this radioactive metal in the Earth's crust. The process of upper mantle and crust fractionation and differentiation is the first cycle of the mobilization process which led to uranium enrichment in rocks in some areas of the upper Earth's crust that could be considered as the primordial uranium provinces. Uranium migration is related to the structural history of sial Earth's crust and sial magmatism. During orogeny conditions could be created for development of progressive metamorphism and for magma generation. The latter is the best process for uranium mobilization. The effectiveness of this process depends on the composition of the primordial rocks and the intensity of the process. The importance of the magmatism for uranium mobilization is due to the magmatic differentiation. Selectively mobilized felsitic parts of the rocks migrate and form felsitic magmatic portions, which mobilize uranium. Solutions are the best uranium mobilization agents. Their generation starts with water separation from local permeable reservoirs and finishes with water dissociation from minerals during their dehydration. Such solutions could be endogenous or exogenous, depending on the igneous or sedimentary rocks which have been deformed. Some of the solutions can have mixed origin, if dethe solutions can have mixed origin, if deformed magmatic rocks contain exogenous water in pores and cracks and endogenous water in minerals. The mobilizing ability of the solutions depends on their energy, which could derive from their chemical compositions and from physical conditions of the geological environment. The movement of the mineralized solutions can be due to steam pressure and the pressure difference between the starting and the final point of the juvenile solutions, gravity for meteoric waters, convection in geoconvection cells, and water pressure in pressured hydrogeological systems. All these types of solution movement are considered, with emphasis on the more common ones. (author). 11 refs, 5 figs

  1. Irregular Migration in Egypt

    OpenAIRE

    NASSAR, Heba

    2008-01-01

    Egypt’s capital Cairo hosts one of the five largest urban refugee populations in the world. For this reason, our paper concentrates on the legal aspect of irregular migration, discussing the characteristics of these migrants as asylum seekers and refugees while also examining transit migrants. First, the paper tackles associated concepts and data issues, with reference to the existing literature and international standards. In the second part, an overview of the Middle East and Northern A...

  2. Migration, Trade and Unemployment

    OpenAIRE

    Heid, Benedikt; Larch , Mario

    2011-01-01

    A source of anxiety of policy makers and the public in general is the detrimental impact of trade and immigration on unemployment. The transitory restrictions for worker migration after the EU enlargements of 2004 and 2007 exemplify the supposed negative effect of immigration on labor markets. This paper aims to identify the effects of immigration alongside trade on unemployment controlling for the high correlation between immigration and goods flows in order to prevent an omitted variable bi...

  3. Migration of gall stones.

    OpenAIRE

    Taylor, T V; Armstrong, C. P.

    1987-01-01

    The factors influencing the migration of gall stones are ill understood. Altogether 331 patients undergoing cholecystectomy were studied prospectively. The diameters of the cystic and common bile ducts and of stones in the gall bladder and bile ducts were measured. Increasing pressure was applied to the freshly excised gall bladder in an attempt to evacuate stones through the cystic duct. Stones passed in 33 (60.0%) of patients with choledocholithiasis, 45 (67.2%) of patients with pancreatiti...

  4. Remittances and temporary migration

    OpenAIRE

    Dustmann, C.; Mestres, J

    2009-01-01

    In this paper we study the remittance behavior of immigrants and how it relates to temporary versus permanent migration plans. We use a unique data source that provides unusual detail on remittances and return plans, and follows the same household over time. Our data allows us also to distinguish between different purposes of remittances. We analyze the association between individual and household characteristics and the geographic location of the family as well as return plans...

  5. Syngas Upgrading to Hydrocarbon Fuels Technology Pathway

    Energy Technology Data Exchange (ETDEWEB)

    Talmadge, M.; Biddy, M.; Dutta, A.; Jones, S.; Meyer, A.

    2013-03-01

    This technology pathway case investigates the upgrading of woody biomass derived synthesis gas (syngas) to hydrocarbon biofuels. While this specific discussion focuses on the conversion of syngas via a methanol intermediate to hydrocarbon blendstocks, there are a number of alternative conversion routes for production of hydrocarbons through a wide array of intermediates from syngas. Future work will also consider the variations to this pathway to determine the most economically viable and lowest risk conversion route. Technical barriers and key research needs have been identified that should be pursued for the syngas-to-hydrocarbon pathway to be competitive with petroleum-derived gasoline-, diesel- and jet-range hydrocarbon blendstocks.

  6. Biodegradation of petroleum hydrocarbons in hypersaline environments

    Scientific Electronic Library Online (English)

    Luiz Fernando, Martins; Raquel Silva, Peixoto.

    2012-09-01

    Full Text Available Literature on hydrocarbon degradation in extreme hypersaline media presents studies that point to a negative effect of salinity increase on hydrocarbonoclastic activity, while several others report an opposite tendency. Based on information available in the literature, we present a discussion on the [...] reasons that justify these contrary results. Despite the fact that microbial ability to metabolize hydrocarbons is found in extreme hypersaline media, indeed some factors are critical for the occurrence of hydrocarbon degradation in such environments. How these factors affect hydrocarbon degradation and their implications for the assessment of hydrocarbon biodegradation in hypersaline environments are presented in this review.

  7. Biodegradation of petroleum hydrocarbons in hypersaline environments

    Directory of Open Access Journals (Sweden)

    Luiz Fernando Martins

    2012-09-01

    Full Text Available Literature on hydrocarbon degradation in extreme hypersaline media presents studies that point to a negative effect of salinity increase on hydrocarbonoclastic activity, while several others report an opposite tendency. Based on information available in the literature, we present a discussion on the reasons that justify these contrary results. Despite the fact that microbial ability to metabolize hydrocarbons is found in extreme hypersaline media, indeed some factors are critical for the occurrence of hydrocarbon degradation in such environments. How these factors affect hydrocarbon degradation and their implications for the assessment of hydrocarbon biodegradation in hypersaline environments are presented in this review.

  8. Secondary Nocturnal Enuresis

    Science.gov (United States)

    ... Contact Us You are here Home » Secondary Nocturnal Enuresis Some children have always wet the bed at ... for a variable period of time. Secondary nocturnal enuresis (SNE) is bedwetting that develops after at least ...

  9. Essays über Secondary Buyouts

    OpenAIRE

    Figge, Christian

    2013-01-01

    Secondary Buyouts, bei denen sowohl auf Verkäufer- als auch Käuferseite ein Private Equity-Unternehmen steht, haben wichtige Implikationen für beide Seiten zur Folge. Zuerst werden Renditepotenzial und Wertsteigerungsprofil von Secondary Buyouts aus der Perspektive des Käufers analysiert. In einem zweiten Schritt stehen dann das Renditepotenzial sowie die Einflussfaktoren bei Secondary Buyouts als möglicher Verkaufskanal im Fokus der Arbeit. Die Resultate zeigen, dass Secondary Buyouts f...

  10. Fast imaging of marine controlled-source EM data using time domain electromagnetic migration

    Science.gov (United States)

    Endo, M.; Furukawa, T.; Zhdanov, M. S.

    2008-12-01

    The application of electromagnetic (EM) methods in petroleum and mining exploration requires development of appropriate imaging techniques, which provide the means for fast but accurate evaluation of the observed data. Time domain electromagnetic (TDEM) methods are widely used in geophysical exploration. However, practical interpretation of TDEM data is mainly based on a simple one-dimensional (1D) inversion of the data at any given observation point. Due to increased interest in the time-domain technique in offshore petroleum exploration with a controlled-source of the EM field, the development of multidimensional interpretation of TDEM data is required. In this paper, a fast approach to TDEM data interpretation using the method of TDEM migration is introduced. The computation of the migration field is based on downward extrapolation of the observed field in reverse time. An effective method of EM migration based on the operator of an integral transformation in the spatial-temporal domain is examined. A migration geoelectrical image is constructed using the convolution of the background and migration fields. Also, the technique is extended for interpretation of TDEM data observed both in land surveys with layered background media and in marine hydrocarbon exploration by introducing an adjoint land geoelectrical model for a given model and a corresponding adjoint field. The accuracy of this imaging technique is demonstrated successfully using synthetic TDEM data simulating mining exploration and hydrocarbon exploration in land and marine survey environments, respectively. The results ensure that this imaging technique works reasonably well.

  11. Ambient aromatic hydrocarbon measurements at Welgegund, South Africa

    Directory of Open Access Journals (Sweden)

    K. Jaars

    2014-02-01

    Full Text Available Aromatic hydrocarbons are associated with direct adverse human health effects and can have negative impacts on ecosystems due to their toxicity, as well as indirect negative effects through the formation of tropospheric ozone and secondary organic aerosol that affect human health, crop production and regional climate. Measurements were conducted at the Welgegund measurement station (South Africa that is considered to be a regionally representative background site. However, the site is occasionally impacted by plumes from major anthropogenic source regions in the interior of South Africa, which include the western Bushveld Igneous Complex (e.g. platinum, base metal and ferrochrome smelters, the eastern Bushveld Igneous Complex (platinum and ferrochrome smelters, the Johannesburg–Pretoria metropolitan conurbation (>10 million people, the Vaal Triangle (e.g. petrochemical and pyrometallurgical industries, the Mpumalanga Highveld (e.g. coal-fired power plants and petrochemical industry and also a region of anti-cyclonic recirculation of air mass over the interior of South Africa. The aromatic hydrocarbon measurements were conducted with an automated sampler on Tenax-TA and Carbopack-B adsorbent tubes with heated inlet for one year. Samples were collected twice a week for two hours during daytime and two hours during night-time. A thermal desorption unit, connected to a gas chromatograph and a mass selective detector was used for sample preparation and analysis. Results indicated that the monthly median total aromatic hydrocarbon concentrations ranged between 0.01 to 3.1 ppb. Benzene levels did not exceed local air quality standards. Toluene was the most abundant species, with an annual median concentration of 0.63 ppb. No statistically significant differences in the concentrations measured during daytime and night-time were found and no distinct seasonal patterns were observed. Air mass back trajectory analysis proved that the lack of seasonal cycles could be attributed to patterns determining the origin of the air masses sampled. Aromatic hydrocarbon concentrations were in general significantly higher in air masses that passed over anthropocentrically impacted regions. Interspecies correlations and ratios gave some indications of the possible sources for the different aromatic hydrocarbons in the source regions defined in the paper. The highest contribution of aromatic hydrocarbon concentrations to ozone formation potential was also observed in plumes passing over anthropocentrically impacted regions.

  12. Ambient aromatic hydrocarbon measurements at Welgegund, South Africa

    Energy Technology Data Exchange (ETDEWEB)

    Jaars, K.; Beukes, J. P.; van Zyl, P. G.; Venter, A. D.; Josipovic, M.; Pienaar, J. J.; Vakkari, Ville; Aaltonen, H.; Laakso, H.; Kulmala, M.; Tiitta, P.; Guenther, Alex B.; Hellen, H.; Laakso, L.; Hakola, H.

    2014-07-11

    Aromatic hydrocarbons are associated with direct adverse human health effects and can have negative impacts on ecosystems due to their toxicity, as well as indirect negative effects through the formation of tropospheric ozone and secondary organic aerosol that affect human health, crop production and regional climate. Measurements were conducted at the Welgegund measurement station (South Africa) that is considered to be a regionally representative background site. However, the site is occasionally impacted by plumes from major anthropogenic source regions in the interior of South Africa, which include the western Bushveld Igneous Complex (e.g. platinum, base metal and ferrochrome smelters), the eastern Bushveld Igneous Complex (platinum and ferrochrome smelters), the Johannesburg-Pretoria metropolitan conurbation (>10 million people), the Vaal Triangle (e.g. petrochemical and industries), the Mpumalanga Highveld (e.g. coal-fired power plants and petrochemical industry) and also a region of anti-cyclonic recirculation of air mass over the interior of South Africa. The aromatic hydrocarbon measurements were conducted with an automated sampler on Tenax-TA and Carbopack-B adsorbent tubes with heated inlet for one year. Samples were collected twice a week for two hours during daytime and two hours 1 during night-time. A thermal desorption unit, connected to a gas chromatograph and a mass 2 selective detector was used for sample preparation and analysis. Results indicated that the 3 monthly median total aromatic hydrocarbon concentrations ranged between 0.01 to 3.1 ppb. 4 Benzene levels did not exceed local air quality standards. Toluene was the most abundant 5 species, with an annual median concentration of 0.63 ppb. No statistically significant 6 differences in the concentrations measured during daytime and night-time were found and no distinct seasonal patterns were observed. Air mass back trajectory analysis proved that the lack of seasonal cycles could be attributed to patterns determining the origin of the air masses sampled. Aromatic hydrocarbon concentrations were in general significantly higher in air masses that passed over anthropocentrically impacted regions. Interspecies correlations and ratios gave some indications of the possible sources for the different aromatic hydrocarbons in the source regions defined in the paper. The highest contribution of aromatic hydrocarbon concentrations to ozone formation potential was also observed in plumes passing over anthropocentrically impacted regions.

  13. International Migration Diversification: A New Perspective to Migration Management

    OpenAIRE

    Bulley, Cynthia A.; Peter Quartey

    2014-01-01

    Diversifying migration for development is an option that much has been discussed and yet little has been done in sending countries. The potential of international migration being harnessed for economic and social development have gained significant importance. Some initiatives have been discussed and launched to manage international migration. Some of these efforts are aimed at addressing the issue of containing the outflow and encouraging return of migrants to help with nation building. But ...

  14. 40 CFR 180.526 - Synthetic isoparaffinic petroleum hydrocarbons; tolerances for residues.

    Science.gov (United States)

    2010-07-01

    ... Synthetic isoparaffinic petroleum hydrocarbons; tolerances for residues... Synthetic isoparaffinic petroleum hydrocarbons; tolerances for residues... Synthetic isoparaffinic petroleum hydrocarbons complying with...

  15. Optimizing Total Migration Time in Virtual Machine Live Migration

    OpenAIRE

    Gustafsson, Erik

    2013-01-01

    The ability to migrate a virtual machine (VM) from one physical host to another is important in a number of cases such as power management, on-line maintenance, and load-balancing. The amount of memory used in VMs have been steadily increasing up to several gigabytes. Consequently, the time to migrate machines, the total migration time, has been increasing. The aim of this thesis is to reduce the total migration time. Previous work aimed at reducing the amount of time and disk space required ...

  16. Hydrocarbon Rocket Technology Impact Forecasting

    Science.gov (United States)

    Stuber, Eric; Prasadh, Nishant; Edwards, Stephen; Mavris, Dimitri N.

    2012-01-01

    Ever since the Apollo program ended, the development of launch propulsion systems in the US has fallen drastically, with only two new booster engine developments, the SSME and the RS-68, occurring in the past few decades.1 In recent years, however, there has been an increased interest in pursuing more effective launch propulsion technologies in the U.S., exemplified by the NASA Office of the Chief Technologist s inclusion of Launch Propulsion Systems as the first technological area in the Space Technology Roadmaps2. One area of particular interest to both government agencies and commercial entities has been the development of hydrocarbon engines; NASA and the Air Force Research Lab3 have expressed interest in the use of hydrocarbon fuels for their respective SLS Booster and Reusable Booster System concepts, and two major commercially-developed launch vehicles SpaceX s Falcon 9 and Orbital Sciences Antares feature engines that use RP-1 kerosene fuel. Compared to engines powered by liquid hydrogen, hydrocarbon-fueled engines have a greater propellant density (usually resulting in a lighter overall engine), produce greater propulsive force, possess easier fuel handling and loading, and for reusable vehicle concepts can provide a shorter turnaround time between launches. These benefits suggest that a hydrocarbon-fueled launch vehicle would allow for a cheap and frequent means of access to space.1 However, the time and money required for the development of a new engine still presents a major challenge. Long and costly design, development, testing and evaluation (DDT&E) programs underscore the importance of identifying critical technologies and prioritizing investment efforts. Trade studies must be performed on engine concepts examining the affordability, operability, and reliability of each concept, and quantifying the impacts of proposed technologies. These studies can be performed through use of the Technology Impact Forecasting (TIF) method. The Technology Impact Forecasting method is a normative forecasting technique that allows the designer to quantify the effects of adding new technologies on a given design. This method can be used to assess and identify the necessary technological improvements needed to close the gap that exists between the current design and one that satisfies all constraints imposed on the design. The TIF methodology allows for more design knowledge to be brought to the earlier phases of the design process, making use of tools such as Quality Function Deployments, Morphological Matrices, Response Surface Methodology, and Monte Carlo Simulations.2 This increased knowledge allows for more informed decisions to be made earlier in the design process, resulting in shortened design cycle time. This paper will investigate applying the TIF method, which has been widely used in aircraft applications, to the conceptual design of a hydrocarbon rocket engine. In order to reinstate a manned presence in space, the U.S. must develop an affordable and sustainable launch capability. Hydrocarbon-fueled rockets have drawn interest from numerous major government and commercial entities because they offer a low-cost heavy-lift option that would allow for frequent launches1. However, the development of effective new hydrocarbon rockets would likely require new technologies in order to overcome certain design constraints. The use of advanced design methods, such as the TIF method, enables the designer to identify key areas in need of improvement, allowing one to dial in a proposed technology and assess its impact on the system. Through analyses such as this one, a conceptual design for a hydrocarbon-fueled vehicle that meets all imposed requirements can be achieved.

  17. Deep desulfurization of hydrocarbon fuels

    Science.gov (United States)

    Song, Chunshan (State College, PA); Ma, Xiaoliang (State College, PA); Sprague, Michael J. (Calgary, CA); Subramani, Velu (State College, PA)

    2012-04-17

    The invention relates to processes for reducing the sulfur content in hydrocarbon fuels such as gasoline, diesel fuel and jet fuel. The invention provides a method and materials for producing ultra low sulfur content transportation fuels for motor vehicles as well as for applications such as fuel cells. The materials and method of the invention may be used at ambient or elevated temperatures and at ambient or elevated pressures without the need for hydrogen.

  18. Mediterranean hydrocarbons pollution from Landsat

    OpenAIRE

    Wald, Lucien; Monget, Jean-Marie; Albuisson, Michel

    1981-01-01

    Previous studies have shown that oil spills have been viewed by Landsat . The setection of oil is mainly due to the variations of reflectance between the sea and the oil spill. This result is used in the framework of the European Project "ARCHIMEDES", lead by the Joint Research Center (Ispra, Italy), which purpose is the study of the pollution in the Mediterranean Sea. 800 Landsat images obtained from 1972 to 1975 were examined. The cumulative area covered by the hydrocarbons spread each year...

  19. Migration experiments in Studsvik

    International Nuclear Information System (INIS)

    Field experiments (two-well pulse method) on the migration of Sr and Cs in a gneiss at Studsvik on the Swedish east coast as well as supporting laboratory measurements on sorption/migration have been performed. Interconnected fractures at about 100 m depth between boreholes were located and characterized. In the boreholes measurements of resistivity, spontaneous potential, pH, Eh, curvature, temperature, gamma radiation, and radon have been performed. The fracture zones were localized, using TV-logging, and the mineralogy of the water bearing fractures in a drill core from the area determined. The main fissure filling minerals were chlorite, calcite and smectite. The groundwater composition was analyzed and it was found that the water in some cases is oversaturated with respect to calcium carbonate. Temperatures up to 12 degreeC of the pumped water have been observed, corresponding to water originating from 200-400 m depth. In laboratory batch measurements it was found that the distribution coefficient for Studsvik gneiss and possible fissure filling minerals was 0.01-0.4 m3/kg. The sorption isotherm for the gneiss was almost linear, a Freundlich isotherm with the exponent 0.89 fits well to the data. In two field experiments, performed between different boreholes, retention factors for Sr of 17 and 30, respectively, were obtained. In laboratory column experiments, performed on crushed borehole material, the retention factor was 30-35, corresponding to a distribution coefficient of 0.006-0.008 m3/kg. For Cs, injected simultanously with the Sr, the retentionfactor is > 30. (No breakthrough after 5000 h.). In both the field experiments a minor amount of the Sr was migrating almost without retention (retention factor < 2). This effect was not observed for Cs, indicating that the process causing the fast transport of Sr is selective to Sr. (author)

  20. Population, desertification, and migration.

    Science.gov (United States)

    Westing, A H

    1994-01-01

    When an imbalance develops between population numbers and the carrying capacity of the land, the persons thereby displaced are referred to as environmental refugees. The utilization of the land beyond sustainability leads to land degradation and ultimately, desertification. The social and political impacts of long-term environmental migration can be distinguished: a) at the site of origin of the displaced persons by the residual population; b) at rural sites of destination within the nation between the new arrivals and preestablished populations; c) in the cities within the nation; d) in the nonindustrialized foreign countries; and e) in the industrialized foreign countries. In the event that an area which had previously been devoted to pastoralism is converted to agriculture, the displaced pastoralists might respond through armed rebellion. In some instances, the disenchanted urban squatters become a politically restive and even a destabilizing force, as occurred in Sudan in the 1980s, especially in Khartoum and Port Sudan. The foreign countries to which many of the displaced persons are migrating are subjected to increasing levels of migrant-induced economic, cultural, and political strains. The growing problems associated with south-to-north migration across the Mediterranean Sea have recently led France, Italy, Portugal, and Spain to enter into a consultative arrangement with Algeria, Libya, Mauritania, Morocco, and Tunisia. All foreign aid to the nonindustrialized countries that attempts to ameliorate the problem of desertification must adopt integrated approaches that: a) address population issues; b) support environmental education; c) provide for the protection of biodiversity; d) encourage participatory forms of local and national government; e) provide opportunities for income generation outside the livestock sector; and f) foster political security and facilitate ecogeographical (subregional) cooperation. PMID:12289925

  1. Hydrocarbon prospectivity in Western Greece

    Energy Technology Data Exchange (ETDEWEB)

    Maravelis, Angelos; Makrodimitras, George; Zelilidis, Avraam [Patras Univ. (Greece). Lab. of Sedimentology

    2012-06-15

    The geology of Western Greece is dominated by the most external zones of the Hellenide fold-and-thrust belt, namely the Pre-Apulian (or Paxoi) and Ionian zones. With Western Greece and Albania having undergone, in broad terms, similar geological histories, also the hydrocarbon potentials of both areas may be compared. Likewise, the hydrocarbon potential of Italy's Apulian Platform, adjoining in the westerly offshore, may serve as an analogue. Three basin types within Western Greece that deserve hydrocarbon exploration have been examined and are grouped, correlated to major tectonic features, namely foreland (Ionian thrusts' foreland basin), piggy-back (Ionian thrusts' back-arc basin) and strike-slip basins. Additionally, strike-slip basins are further subdivided into the basin north of the Borsh-Khardhiqit strike-slip fault and the Preveza basin, north of Cephalonia transfer fault. Their filling histories suggest the occurrence of Mesozoic carbonate plays and Oligocene/Miocene sandstone plays both for oil and gas.

  2. Migration and loving

    OpenAIRE

    Gevrek, Deniz

    2010-01-01

    This paper explores the relationship between anti-miscegenation laws, interracial marriage and black males' geographical distribution in the U.S. during and after the Great Migration. The U.S. Supreme Court decision in the case of Loving v. Virginia in 1967, which forced the last 16 Southern states to strike down their anti-miscegenation laws, creates a unique opportunity to explore the impact of an exogenous change in a state's laws regulating interracial marriages. Analyzing the U.S. Census...

  3. Climate and Human Migrations

    Science.gov (United States)

    Tom D. Dillehay (University of Kentucky; Department of Anthropology)

    2002-10-25

    Access to the article is free, however registration and sign-in are required. About 14,600 years ago, humans first appeared in south central Chile. But the arid regions of the Atacama desert in northern Chile were not populated for another 2000 years, and human occupation of this region subsequently remained intermittent. In his Perspective, Dillehay highlights the report of Núñez et al., whose integrative archaeological and paleoecological study shows that climate was the key factor in these human migrations. The study illustrates the power of an integrative approach to understanding the relation between human societies and climate change.

  4. Amenity migration and tourism.

    Czech Academy of Sciences Publication Activity Database

    Bartoš, Michael; Kušová, Drahomíra; T?šitel, Jan

    Tábor : University of South Bohemia ?eské Bud?jovice, University of Economics Bratislava, 2005 - (Hesková, M.; Šittler, E.; Dvo?ák, V.), s. 17-21 ISBN 80-7040-766-2. [Tourism, regional development and education. Sustainable development and tourism. Tábor (CZ), 12.05.2005-13.05.2005] Grant ostatní: EU(XE) European Union/'s Quality of Life and Management of Living Resources programme:QLK5-CT-2000-01211-SPRITE Institutional research plan: CEZ:AV0Z60870520 Keywords : sustainable tourism * amenity migration * regional development Subject RIV: AE - Management ; Administration

  5. Objectivity Data Migration

    OpenAIRE

    Nowak, Marcin; Nienartowicz, Krzysztof; Valassi, Andrea; Lubeck, Magnus; Geppert, Dirk

    2003-01-01

    In this article we describe the migration of event data collected by the COMPASS and HARP experiments at CERN. Together these experiments have over 300TB of physics data stored in Objectivity/DB that had to be transferred to a new data management system by the end of Q1 2003 and Q2 2003 respectively. To achieve this, data needed to be processed with a rate close to 100MB/s, employing 14 tape drives and a cluster of 30 Linux servers. The new persistency solution to accommodat...

  6. Trimming of a migrated metal stent for malignant colonic stricture using argon plasma coagulation

    OpenAIRE

    Kiran Venkat Rao; Gagan Deep Beri; Weizheng William Wang

    2010-01-01

    We report the first case of trimming of a migrated metal colonic stent for stent induced severe anorectal pain. We present a case of a 54-year-old female with history of metastatic colorectal carcinoma who had stent placement secondary to obstruction. Subsequent distal migration of the stent caused ulcerations into the rectal mucosa and excruciating anorectal pain. We used argon plasma coagulation (APC) to successfully trim the exposed distal portion of the metal stent and rat tooth forceps t...

  7. Migration of clips after laparoscopic cholecystectomy; a case report and literature review.

    Science.gov (United States)

    Ghavidel, Ali

    2015-01-01

    Postcholecystectomy clip migration is rare and can lead to complications such as clip-related biliary stones. Most of such incidents have been reported as case reports. This study reviews a case of postcholecystectomy clip migration. It can occur at any time but typically occur at a median of 2 years after cholecystectomy. Clinical presentations are similar to those with primary or secondary choledocholithiasis. Most cases can be managed successfully with ERCP. PMID:25628854

  8. Surgical clip migration following laparoscopic cholecystectomy as a cause of cholangitis

    OpenAIRE

    Photi, Evangelos S.; Partridge, Gemma; Rhodes, Michael; Lewis, Michael P. N.

    2014-01-01

    Gallstone disease is a common surgical presentation, and laparoscopic cholecystectomy is the favoured method of surgical management. Ligation of the cystic duct is usually performed with surgical clips, which have the potential to migrate into the common bile duct with time. This paper describes a case of cholangitis secondary to clip migration in a 42-year-old male patient 9 years after the initial laparoscopic cholecystectomy. Magnetic resonance cholangiopancreaography imaging revealed a su...

  9. Families, children, migration and AIDS

    OpenAIRE

    Haour-Knipe, Mary

    2009-01-01

    Migration is very often a family affair, and often involves children, directly or indirectly. It may give rise to better quality of life for an entire family, or to bitter disappointment, and may also increase vulnerability to HIV and AIDS. This review, carried out for the Joint Learning Initiative on Children and AIDS, links the literature on “migration”, on “HIV and AIDS” and on “families”. Three themes are sketched: (1) As both HIV prevalence and circular migration increase, fo...

  10. Migration and the Demographic Shift

    OpenAIRE

    Zaiceva, Anzelika; Zimmermann, Klaus F.

    2014-01-01

    This chapter connects population aging with international migration. After documenting the trends for both, we review the supply-push and demand-pull determinants of migration, focusing particularly on the role of age and aging. We subsequently discuss the literature concerning the implications of migration in the context of aging for labor markets, health and public budgets including the political economy context. Although immigration is sometimes suggested as a solution for the aging proble...

  11. Social Union, Convergence and Migration

    OpenAIRE

    Sinn, Hans-werner; Ochel, Wolfgang

    2003-01-01

    The forces of the market and systems competition bring about economic and social convergence in Europe, and there is no need for social policies at the EU level. Social harmonization would distort migration flows and slow down the speed of economic convergence. National welfare states will be threatened by the free migration of people in Europe. The race to the bottom is a serious risk. However, to contain this risk, neither harmonization of welfare payments nor constraints on migration are n...

  12. Bayesian estimation in seismic migration

    OpenAIRE

    Pitas, I.; Venetsanopoulos, A.

    2010-01-01

    Seismic migration is a technique widely used in seismic oil exploration for wavefield reconstruction and for imaging the geometrical distribution of the reflection surfaces within the Earth from the seismic data recorded on the Earth surface. These data are usually corrupted by noise (white noise, surface waves, multiple reflections, etc.) that degrades the result of the migration. Another factor which influences the migration is the inadequate knowledge of the distribution of the acoustic wa...

  13. Assessment of the Moroccan Mediterranean Coasts Contamination by Hydrocarbons (Non Aromatic Hydrocarbons, Aromatic Hydrocarbons and Linear Alkylbenzenes)

    OpenAIRE

    Saida Bouzid; Soumaya Khannous; Ioanna Bouloubassi; Alain Saliot; Hassan Er Raioui

    2011-01-01

    In order to evaluate the contamination of the Moroccan Mediterranean coasts by persistent organic pollutants we studied hydrocarbons and linear alkylbenzenes in bivalve tissues (cockles) collected seasonally from several points along the western Moroccan coasts in the Mediterranean Sea. Two fractions corresponding to non aromatic and aromatic hydrocarbons were analyzed by GC/FID and GC/MS. Non aromatic hydrocarbon concentrations vary in the range of 24.1 - 2731 ?g/g dry weight (dw) while tot...

  14. A study of hydrocarbon contamination in glacial till

    International Nuclear Information System (INIS)

    A pre-acquisition environmental assessment was conducted for an Alberta site in a commercial district, leading to the detection of petroleum hydrocarbons, characterized as diesel fuel, in several boreholes. A ground penetrating radar scan led to the removal of a 1000 gallon and a 10,000 gallon tank from the site. It was determined that leakage from two 5000 gallon tanks previously installed was responsible for the hydrocarbon contamination. An extensive site investigation revealed that leaked diesel products had migrated downward and spread laterally within a sandy silt layer of a lacustrine deposit and inter-till sand pockets. In-situ conductivity tests for the free product bearing soils were carried out. The area of contamination was estimated to be greater than 7000 m3 at depths extending between 4 and 15 m below grade. A series of field recovery tests were conducted to assess the recovery characteristics and flow dynamics of the free product bearing soil deposits, with ca 3700 liters of diesel product removed over a six month period. A pneumatic pulse pump system was used to implement a well recovery program, and ca 600 liters of product was removed within a month period. Once product removal is completed, the site will be developed with an underground car-park with contaminated soils removed during construction. 7 refs., 9 figs

  15. Underground radionuclide migration

    International Nuclear Information System (INIS)

    The number 9 sub-report of the safety assesment studies of the disposal of radioactive waste in rock-salt formations concerns the calculation of radio-nuclide migration with groundwater. Calculations ar carried out in two phases. The first phase consists of calculation of the groundwater flow system under a great number of different hydrological boundary conditions, which possibly can be encountered in future. Variations in sea level and consequences of glaciations are included. Given a great number of possible groundwater flow systems, in the second phase radionuclide migration is calculated for a restricted number of representative situations. Transport of radionuclides with groundwater takes place, starting at a release point at the top (edge) of the rock salt formation until the landsurface, the bottom of a sea or an extraction-well for public water supply has been reached, at which places concentrations radionuclides have been computed as a function of time. Calculations continued till all concentrations had reached their maxima. Results form the input for biosphere dose-calculations, as reported in the number 10 sub-report. (author). 26 refs.; 43 figs.; 22 tabs

  16. Amenity migration as an example of the environmental migration.

    Czech Academy of Sciences Publication Activity Database

    Bartoš, Michael; Kušová, Drahomíra; T?šitel, Jan

    Newcastle upon Tyne : Cambridge Scholars Publishing, 2008, s. 58-75. ISBN 978-1-4438-0038-9 R&D Projects: GA ?R(CZ) GA403/07/0714 Institutional research plan: CEZ:AV0Z60870520 Keywords : amenity migration * environmental migration * local development Subject RIV: AO - Sociology, Demography

  17. Kinetic model describing the composition of hydrocarbons generated by three major types of organic matter

    Energy Technology Data Exchange (ETDEWEB)

    Doligez, B.; Ungerer, P.; Espitalie, J.; Ducreux, C.; Heum, O.R.; Eggen, S.

    1988-08-01

    The prediction of hydrocarbon composition as a function of thermal history and type of source rock is of great economic importance, but few models have considered this problem. We propose a kinetic model which couples the primary cracking (oil and gas generation from the sedimentary organic matter) with the secondary cracking (degradation of oil into gas and carbonaceous residue). Used for primary as well as secondary cracking, the model involves four hydrocarbon fractions: methane, wet gas, light oil, and heavy oil. The primary cracking is treated by a set of parallel reactions, and the secondary cracking of each hydrocarbon fraction is described by a balanced reaction (except methane, which is considered stable). Progressive expulsion of hydrocarbons without fractionation is also accounted for. The kinetic parameters of the model are calibrated with results of pyrolysis experiments. This has been achieved for the three classical types of organic matter. The model reproduces fairly well the pyrolysis experiments for a large range of temperatures (300 to 550/degree/C) and heating times (1 to 48 hr). Model simulations have been performed with typical geologic rates of burial and temperature increase. They show that the model accounts well for the successive stages of heavy oil, light oil, gas condensate, and dry gas formation at depths consistent with well-known trends. In addition to the classical influence of thermal history and organic type on the composition of hydrocarbons, expulsion appears to have a considerable influence in this respect: early expulsion promotes the formation of oil; late expulsion favors gas generation.

  18. Rotliegend red bed reservoirs: how important is organic maturation and migration?

    Energy Technology Data Exchange (ETDEWEB)

    Schoener, R.; Gaupp, R. [Jena Univ. (Germany)

    2003-07-01

    The interaction of organic maturation products and clastic reservoir rocks has mainly been studied with regard to petrophysical property evolution or metal-organic interactions. Compared to previous studies, we are focussing on integrated investigations of the mineralogical processes involved in the interaction of sandstones with organic maturation products. An improved understanding of the chemical interaction of red bed arkosic sandstones and hydrocarbons should enable the better assessment of whether such a clastic horizon has been subjected to hydrocarbon migration in the geological past or not. Neither organic traces are necessarily detectable after long burial and exposure to elevated temperatures nor do fluid inclusion studies reliably exhibit former hydrocarbon fluid contents in cements. However, the minor traces of authigenic minerals respectively distinctive petrographic features related to former presence of organic maturation products could be used as finger prints of past hydrocarbon migrations and allow tracing fluid flow paths in basin analytical work. This article gives an overview on the approaches and the present state of investigations. (orig.)

  19. Software Engineering Challenges of Migration Projects

    OpenAIRE

    S.Geetha; Dr.Alagaramy

    2012-01-01

    Organisations often face the challenges of migration from legacy systems to new target systems. Such migration efforts represent a complex engineering problem. This paper describes migration planning, identifies influencing factors, outlines a set of migration planning activities and offers a set of guidelines for the migration planning

  20. AUTOMOTIVE HYDROCARBON EMISSION PATTERNS AND THE MEASUREMENT OF NONMETHANE HYDROCARBON EMISSION RATES

    Science.gov (United States)

    The advent of emission control technology has resulted in significant changes in both the total mass and detailed patterns of hydrocarbons emitted from automobiles. Emission rates of 56 hydrocarbons from 22 motor vehicles, including catalyst and noncatalyst configurations, were d...

  1. Exploring the factors influencing the cloud computing adoption: a systematic study on cloud migration.

    Science.gov (United States)

    Rai, Rashmi; Sahoo, Gadadhar; Mehfuz, Shabana

    2015-01-01

    Today, most of the organizations trust on their age old legacy applications, to support their business-critical systems. However, there are several critical concerns, as maintainability and scalability issues, associated with the legacy system. In this background, cloud services offer a more agile and cost effective platform, to support business applications and IT infrastructure. As the adoption of cloud services has been increasing recently and so has been the academic research in cloud migration. However, there is a genuine need of secondary study to further strengthen this research. The primary objective of this paper is to scientifically and systematically identify, categorize and compare the existing research work in the area of legacy to cloud migration. The paper has also endeavored to consolidate the research on Security issues, which is prime factor hindering the adoption of cloud through classifying the studies on secure cloud migration. SLR (Systematic Literature Review) of thirty selected papers, published from 2009 to 2014 was conducted to properly understand the nuances of the security framework. To categorize the selected studies, authors have proposed a conceptual model for cloud migration which has resulted in a resource base of existing solutions for cloud migration. This study concludes that cloud migration research is in seminal stage but simultaneously it is also evolving and maturing, with increasing participation from academics and industry alike. The paper also identifies the need for a secure migration model, which can fortify organization's trust into cloud migration and facilitate necessary tool support to automate the migration process. PMID:25977891

  2. Volatile hydrocarbons inhibit methanogenic crude oil degradation

    OpenAIRE

    AngelaSherry; RussellJGrant

    2014-01-01

    Methanogenic degradation of crude oil in subsurface sediments occurs slowly, but without the need for exogenous electron acceptors, is sustained for long periods and has enormous economic and environmental consequences. Here we show that volatile hydrocarbons are inhibitory to methanogenic oil biodegradation by comparing degradation of an artificially weathered crude oil with volatile hydrocarbons removed, with the same oil that was not weathered. Volatile hydrocarbons (nC5-nC10, methylcyclo...

  3. Microbial degradation of hydrocarbons in the environment.

    OpenAIRE

    Leahy, J. G.; Colwell, R. R.

    1990-01-01

    The ecology of hydrocarbon degradation by microbial populations in the natural environment is reviewed, emphasizing the physical, chemical, and biological factors that contribute to the biodegradation of petroleum and individual hydrocarbons. Rates of biodegradation depend greatly on the composition, state, and concentration of the oil or hydrocarbons, with dispersion and emulsification enhancing rates in aquatic systems and absorption by soil particulates being the key feature of terrestrial...

  4. Oil based synthetic hydrocarbon drilling fluid

    International Nuclear Information System (INIS)

    This patent describes an improved continuous phase for an oil based drilling fluid, the continuous phase being characterized by minimal toxicity to plant and aquatic life and environmental compatibility. It comprises: a synthetic hydrocarbon oil, the synthetic hydrocarbon oil having an average molecular weight of from about 120 to about 1000 the synthetic hydrocarbon oil being synthesized from one or more olefinic monomers having a chain length of C2 to C14

  5. HYDROCARBON AND SULFUR SENSORS FOR SOFC SYSTEMS

    Energy Technology Data Exchange (ETDEWEB)

    A.M. Azad; Chris Holt; Todd Lesousky; Scott Swartz

    2003-11-01

    The following report summarizes work conducted during the Phase I program Hydrocarbon and Sulfur Sensors for SOFC Systems under contract No. DE-FC26-02NT41576. For the SOFC application, sensors are required to monitor hydrocarbons and sulfur in order to increase the operation life of SOFC components. This report discusses the development of two such sensors, one based on thick film approach for sulfur monitoring and the second galvanic based for hydrocarbon monitoring.

  6. Before the Bonanza: Hydrocarbons in Greenland

    OpenAIRE

    Meinild, Ebbe Dam

    2010-01-01

    The issue of Greenlandic hydrocarbons gradually moved towards the centre of the creation of autonomous Greenland. Hydrocarbons in Greenland and the Greenlandic nation were co-produced in the same process. Thus, when hydrocarbons were connected to an ecological modernisation it allowed the newly formed Home Rule administration, in a joint Danish-Greenlandic effort, to adopt this, not only as a road to independence, but as something giving credibility to Greenland as a distinct society.

  7. Hydrocarbon-degrading sulfate-reducing bacteria in marine hydrocarbon seep sediments

    OpenAIRE

    Kleindienst, Sara

    2012-01-01

    Microorganisms are key players in our biosphere because of their ability to degrade various organic compounds including a wide range of hydrocarbons. At marine hydrocarbon seeps, more than 90% of sulfate reduction (SR) is potentially coupled to non-methane hydrocarbon oxidation. Several hydrocarbon-degrading sulfate-reducing bacteria (SRB) were enriched or isolated from marine sediments. However, in situ active SRB remained largely unknown. In the present thesis, the global distribution and a...

  8. The effect of hydrocarbons on the microstructural evolution in rock salt: a case study on hydrocarbon bearing Ara salt from the South Oman Salt Basin

    Science.gov (United States)

    Schmatz, Joyce; Urai, Janos L.; Wübbeler, Franziska M. M.; Sadler, Marc

    2014-05-01

    It has been shown that dilatant deformation promotes the incorporation of hydrocarbons into typically low permeable rock salt (Schoenherr et al., 2007). However, there is not much knowledge on subsequent mechanisms related to recrystallization processes, which cause morphological and chemical changes of the carbonic inclusions. This work aims to contribute to an increased understanding of fluid inclusion dynamics related to grain boundary migration recrystallization and hence to facilitate the interpretation of complex microstructures in recrystallized, multiphase salt rocks. In this case study we investigate hydrocarbon-impregnated salt from the Cambrian Ara Group in the South Oman Salt Basin. The samples were cored from cm-m thick anhydrite-salt sequences overlying hydrocarbon bearing carbonate stringers in 3300 m depth. The anhydrite layers consist mainly of fine-grained anhydrite, which contains calcite, dolomite, and olivine inclusions. Solid bitumen and lighter hydrocarbon phases are observed in between the anhydrite grains and along cracks. Anhydrite layers host salt veins, which contain fragments of anhydrite. These fragments do not differ in composition or structure from the host material and the related vein microstructures indicate crack-seal mechanisms. Halite in the salt layers is almost entirely recrystallized with solid inclusions consisting of anhydrite, calcite, dolomite and olivine with hydrocarbon-coatings present inside grains and along grain boundaries. Solid inclusions cause pinning indicated by a decreased recrystallized grain size and by the presence of grains with preserved substructures representing earlier deformation phases. We observe two types of carbonic inclusions: I) solid bitumen coatings along grain boundaries and microcracks, interpreted to be incorporated into the salt in an overpressure state that allowed dilatancy of the salt, and II) less degraded, liquid hydrocarbons along grain boundaries in the vicinity of the anhydrite, interpreted to be incorporated into the salt in a subsequent deformation phase. Type II inclusions usually form arrays of isolated inclusions (liquid hydrocarbons, vapor, and aqueous phases in minor proportions) along grain boundaries of the recrystallized grains, presumably formed in a surface-energy controlled shrinking process from thin fluid films. Here, the contact with mobile grain boundaries promoted necking down and decomposition of multiphase inclusions. We present a model, which describes the dynamic behavior of liquid hydrocarbons in mobile grain boundaries after their enclosure into the salt layers. The model is based on numerous microanalytical methods, such as optical microscopy, fluorescence microscopy, cryo-SEM, and EDX. Schoenherr, J., et al. (2007), Limits to the sealing capacity of rock salt: A case study of the infra-Cambrian Ara Salt from the South Oman salt basin, AAPG Bulletin, 91(11), 1541-1557

  9. Detection of hydrocarbons in irradiated foods

    Energy Technology Data Exchange (ETDEWEB)

    Miyahara, Makoto; Maitani, Tamio [National Inst. of Health Sciences, Tokyo (Japan); Saito, Akiko; Kamimura, Tomomi; Nagasawa, Taeko [Kitasato Univ., Sagamihara, Kanagawa (Japan). School of Allied Health Sciences; Kobayashi, Yasuo; Ito, Hitoshi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Establishment

    2003-06-01

    The hydrocarbon method for the detection of irradiated foods is now recognized as the international technique. This method is based on radiolysis of fatty acids in food to give hydrocarbons. In order to expand this technique's application, ten foods (butter, cheese, chicken, pork, beef, tuna, dry shrimp, avocado, papaya, and mango) were irradiated in the range from 0.5 to 10 kGy and the hydrocarbons in them were detected. Recoveries of the hydrocarbons from most foods were acceptable (38-128%). Some hydrocarbons were found in non-irradiated foods, particularly, in butter, cheese, tuna, and shrimp. Seven irradiated foods, butter, cheese, chicken, beef, pork, tuna, dry shrimp, and avocado were detectable at their practical doses by measuring the appropriate marker hydrocarbons. In most case, marker hydrocarbon will be 1,7-hexadecadiene. However, the marker hydrocarbons produced only in irradiated foods varied from food to food; therefore, it is necessary to check a specific irradiated food for marker hydrocarbons. On the other hand, two irradiated foods (papaya and mango which were irradiated at their practical doses) were difficult to distinguish from non-irradiated foods using this method. (author)

  10. Process for removing polonium from hydrocarbons

    International Nuclear Information System (INIS)

    A process is described for removing traces of Po from hydrocarbons and particularly from natural gas condensates and other distilled hydrocarbons. The hydrocarbon is contacted with an ion exchange resin having a surface area not less than 1 m2/g and should contain strongly acidic and/or strongly basic exchange groups. A strongly acidic sulphonic acid resin is suitable or a resin containing dimethylhydroxyethylamino, trimethylamino or a mixture of one or more of these groups and sulphonic acid groups. The hydrocarbon is passed through the ion exchange column at a rate of 5 to 10 column volumes per hour. (U.K.)

  11. Detection of hydrocarbons in irradiated foods

    International Nuclear Information System (INIS)

    The hydrocarbon method for the detection of irradiated foods is now recognized as the international technique. This method is based on radiolysis of fatty acids in food to give hydrocarbons. In order to expand this technique's application, ten foods (butter, cheese, chicken, pork, beef, tuna, dry shrimp, avocado, papaya, and mango) were irradiated in the range from 0.5 to 10 kGy and the hydrocarbons in them were detected. Recoveries of the hydrocarbons from most foods were acceptable (38-128%). Some hydrocarbons were found in non-irradiated foods, particularly, in butter, cheese, tuna, and shrimp. Seven irradiated foods, butter, cheese, chicken, beef, pork, tuna, dry shrimp, and avocado were detectable at their practical doses by measuring the appropriate marker hydrocarbons. In most case, marker hydrocarbon will be 1,7-hexadecadiene. However, the marker hydrocarbons produced only in irradiated foods varied from food to food; therefore, it is necessary to check a specific irradiated food for marker hydrocarbons. On the other hand, two irradiated foods (papaya and mango which were irradiated at their practical doses) were difficult to distinguish from non-irradiated foods using this method. (author)

  12. Secondary Controlled Swing Drive

    OpenAIRE

    Pettersson, Karl

    2008-01-01

    The purpose of the thesis has been to design and simulate different concepts of a secondary controlled swing drive for a wheel excavator. Secondary control is a known technology in the field of hydraulics that offers precise positioning as well as the possibility of energy recuperation. Secondary control is today used in certain industrial applications and is rather unemployed in mobile machinery. An excavator moves high loads in cyclic motions which are ideal conditions for energy recuperati...

  13. Secondary Surveillance Radar Antenna

    OpenAIRE

    Schejbal, Vladimír; Bezoušek, Pavel; Pidani?, Jan; Chyba, Milan

    2013-01-01

    This paper deals with a secondary surveillance radar (SSR) array antenna, which is intended for a system combining the secondary surveillance radar antenna and the primary surveillance radar antenna. It describes the patch array elements and the synthesis for the secondary surveillance radar array, considering both elevation and azimuth patterns for sum, difference, and sidelobe-suppression beams, and suspended stripline couplers. The utilization of multilayer techniques allows the connection...

  14. Migrating foreign body from hypopharynx.

    DEFF Research Database (Denmark)

    Mowinckel, Marius Storm; Charabi, Birgitte Wittenborg

    2014-01-01

    In this case report we present a 20-month-old girl with a migrating foreign body, a "smiley" sticker, that migrated from hypopharynx to surrounding tissue and created an abscess with a fistula, one year after ingestion. The foreign body was removed without difficulty under general anaesthesia, and the patient was discharged after few days with peroral antibiotics.

  15. Africa: Setting for Human Migration

    Science.gov (United States)

    Buuba, Babacar Diop

    2007-01-01

    Analysis of African migrations can help to understand prehistoric, historical, ancient modern and contemporaneous migrations. Movements of populations were and continue to be so intense that, for some analysts, they constitute one of the dominant trends of the history and destiny of the very old continent. African and non-African states, whether…

  16. Migration, Diaspora et développement humain

    OpenAIRE

    Bouoiyour, Jamal

    2006-01-01

    This contribution aims to provide some understanding of migration issues in the case of Morocco. This is to recall the various initiatives taken by the Moroccan authorities to strengthen ties between Morocco and migrants. An analysis of the evolution of remittances and their impact on the economy is proposed. Similarly, we address the problem of migration of highly skilled labor in the Moroccan case.

  17. The economics of circular migration

    OpenAIRE

    Constant, Amelie F.; Nottmeyer, Olga; Zimmermann, Klaus F.

    2012-01-01

    Circular migration receives increasing attention due to its empirical relevance and as a policy concept to manage labor flows. This review discusses the advantages and disadvantages of circular movements for all parties. It studies the characteristics of circular movers worldwide and investigates the consequences of restrictive migration policies. Recent policy initiatives that aim to manage circular labor movement are also analyzed.

  18. Paleo oil- and gasfields in the Rotliegend of the North German Basins. Effects upon hydrocarbon reservoir quality

    Energy Technology Data Exchange (ETDEWEB)

    Gaupp, R.; Baunack, C.; Pudlo, D. [Jena Univ. (DE). Institut fuer Geowissenschaften] [and others

    2005-01-01

    An integrated study was performed with the objective to improve reservoir quality prediction from 3D seismics, geological data and concepts. Seismic facies classes, derived from neural network analysis, correlate with reservoir characteristics. They can be used for predictive exploration purposes. Deformation zones indicate the extent of extensional fractures, which can have positive or negative effects on reservoir characteristics, depending on the diagenetic facies. The diagenetic conceptional model has been substantiated, verified in essential parts, and extended (inversion of reservoir qualities), based on well data, modelling and seismic analysis. petroleum system modelling added the time frame for diverse relevant processes and enabled to evaluate their effects on hydrocarbon migration. The importance of pre-oil hydrocarbon migration and spatial distance to carboniferous source rocks for Rotliegend reservoir characteristics must be stressed. (orig.)

  19. Radionuclide Migration: Prediction Experience

    International Nuclear Information System (INIS)

    Many different methods of calculating radionuclide migration (transfer) with groundwater-from very simple handmade calculations to use of sophisticated computer models, - exist and are in use. There is no doubt whether we can solve a particular problem in this area; the question is how can we find means of doing this in a fast, precise and economical way. According to practical experience of MosSIA 'Radon' specialists it is useful at the first stage to assess the degree to which various parameters affect the final result. Then the relevance of modeling parameters is usually assessed. SUE MosSIA 'Radon' has applied this complex approach to assessing possible radionuclide transfer from the long term storage facilities located within one of the sites in Moscow. Questions of model verification, computer realization, the analysis of obtained results, a role and a place of these calculations in safety assessment and safety case are beyond the scope of this paper. (authors)

  20. Chandra Contaminant Migration Model

    Science.gov (United States)

    Swartz, Douglas A.; O'Dell, Steve L.

    2014-01-01

    High volatility cleans OBFs and low volatility produces a high build-up at OBF centers; only a narrow (factor of 2 or less) volatility range produces the observed spatial pattern. Simulations predict less accumulation above outer S-array CCDs; this may explain, in part, gratings/imaging C/MnL discrepancies. Simulations produce a change in center accumulation due solely to DH heater ON/OFF temperature change; but a 2nd contaminant and perhaps a change in source rate is also required. Emissivity E may depend on thickness; another model parameter. Additional physics, e.g., surface migration, is not warranted at this time. At t approx. 14 yrs, model produced 0.22 grams of contaminant, 0.085 grams remaining within ACIS cavity; 7 percent (6mg) on OBFs.

  1. Objectivity Data Migration

    CERN Document Server

    Nowak, M; Valassi, Andrea; Lubeck, M; Geppert, D; Geppert, Dirk

    2003-01-01

    In this article we describe the migration of event data collected by the COMPASS and HARP experiments at CERN. Together these experiments have over 300TB of physics data stored in Objectivity/DB that had to be transferred to a new data management system by the end of Q1 2003 and Q2 2003 respectively. To achieve this, data needed to be processed with a rate close to 100MB/s, employing 14 tape drives and a cluster of 30 Linux servers. The new persistency solution to accommodate the data is built upon relational databases for metadata storage and standard "flat" files for the event data. The databases contain collections of 109 events and allow generic queries or direct navigational access to the data, preserving the original C++ user API. The central data repository at CERN is implemented using several Oracle9i servers on Linux and the CERN Mass Storage System CASTOR.

  2. Anomalous dynamics of cell migration

    CERN Document Server

    Dieterich, Peter; Preuss, Roland; Schwab, Albrecht; 10.1073/pnas.0707603105

    2009-01-01

    Cell movement, for example during embryogenesis or tumor metastasis, is a complex dynamical process resulting from an intricate interplay of multiple components of the cellular migration machinery. At first sight, the paths of migrating cells resemble those of thermally driven Brownian particles. However, cell migration is an active biological process putting a characterization in terms of normal Brownian motion into question. By analyzing the trajectories of wildtype and mutated epithelial (MDCK-F) cells we show experimentally that anomalous dynamics characterizes cell migration. A superdiffusive increase of the mean squared displacement, non-Gaussian spatial probability distributions, and power-law decays of the velocity autocorrelations are the basis for this interpretation. Almost all results can be explained with a fractional Klein- Kramers equation allowing the quantitative classification of cell migration by a few parameters. Thereby it discloses the influence and relative importance of individual comp...

  3. Sealing mechanisms at pore scale, and consequences for hydrocarbon exploration

    Energy Technology Data Exchange (ETDEWEB)

    Teige, Gunn Mari Grimsmo

    2008-11-15

    This dissertation was motivated by the realization that four concepts, which are too simplistic, are widely assumed in the petroleum industry: First, mechanical compaction and associated disequilibrium compaction are frequently assumed to be the main mechanism for overpressure formation, although data are rarely given to support this assumption. This thesis concludes that neither the North Sea nor the Haltenbanken shales compacted mechanically at moderate to deep burial. Therefore, high over pressures in these rocks were not caused by disequilibrium compaction, but more likely by diagenetic processes that were largely unaffected by fluid pressures. Traditional seismic and log-based pore pressure detection methods in these areas should be expected to result in under-prediction of fluid over pressures because the porosities are not higher in over pressured shales than in normally pressured shales. Second, observations of zods (zones of deteriorated seismic signals; at times termed gas chimneys) are often interpreted as evidence of hydrocarbon leakage. This thesis concludes that the occurrence of zods may identify hydrocarbon leakages and where pressure compartments leak. However, prior to interpreting these zones as hydrocarbon leakage, the interpreter must be aware of the various geological processes and non-geological origins that could cause such velocity variations: (a) hydrocarbon leakage, (b) leakage of water with dissolved gas (that could create an inhomogeneous gas saturation), (c) fault or fracture zones themselves, (d) fluid leakage above fault(s) or fault junction, or (e) data quality issues. As a result, applications of zods in hydrocarbon prospect evaluation should be performed more carefully than what is often seen in the industry today. Third, the consequences of high over pressures are often assumed to be hydrocarbon leakage through the cap rock - either because of hydro-fracturing or because high water pressure force oil or gas through membrane seals. This thesis concludes that high over pressures are compatible with hydrocarbon preservation. Vertical water leakage from the apex of a trap may take place while oil and gas are retained by capillary forces within the structure. This result is consistent with the fact that several of the largest oil fields on the Norwegian Continental Shelf (Statfjord, Gullfaks, Snorre, Visund, and Kvitebjoern) are highly over pressured and leaky, and yet contain vast amounts of oil and gas. Finally, vertical leakage is often assumed to occur as separate phase oil flow through water-wet cap rock shales, and membrane seals will, according to the definition of capillary entry pressure, preserve oil indefinitely as long as the critical pore throats are sufficiently small. This thesis concludes that residual water, which flows through reservoirs and cap rocks, carries polar compounds that locally change the cap rock wettability, thus resulting in the formation of oil-wet flow paths. This suggestion explains how pore-scale migration can take place through cap rock shales without resulting in extensive oil saturation in these shales. The suggestion further implies that membrane seals deteriorate with time, thus promoting the transient nature of oil pools that are observed, but that are not compatible with endless membrane sealing time. (Author)

  4. Neural Crest Cell Migration

    Science.gov (United States)

    PhD Jack D Thatcher (West Virginia School of Osteopathic Medicine Structural Biology)

    2010-11-29

    This simple FlashTM animation depicts migration of neural crest cells throughout the mesoderm of the neurulating germ disc. For context it opens with a cross section of the germ disc showing the neural crests at the dorsal end of the neural tube. It then turns to a lateral view, which allows users to observe neural crest cells separating from the crests and migrating into the mesoderm along the neural tube or epidermis. A back button allows users to jump to previous scenes, a rate button allows them to toggle between fast and slow modes, and a text button allows them to toggle explanatory text on and off. Instructions for opening animation with Windows system. 1. Double click the icon for the SWF. 2. A dialog box may pop up that begins with the statement "Windows cannot open this file:" If this box does not appear proceed to step 4. If it does choose "Select the program from a list," then click OK. 3. Another dialog box will pop up that lists different programs. Make sure " Internet Explorer" is selected, then click OK. 4. A Window for Internet Explorer will pop up. Beneath the toolbars at the top of the window a yellow bar will appear that reads "To help protect your security, Internet Explorer has restricted this webpage from running scripts or Active X controls that could access your computer. Click here for options..." Pass the cursor over this yellow bar and click the right mouse button. 5. A dialog box will pop up. Left click the option "Allow Blocked Content." 6. Another dialog box will appear labeled "Security Warning" asking you to confirm that you want to run the content. Click "Yes." 7. The Flash animation will appear in the Internet Explorer Window. 8. Left click anywhere in the animation to advance the display. 9. Read instructions provided by the animation for additional controls such as navigation buttons.

  5. Kinetics of NCO + hydrocarbon reactions

    Science.gov (United States)

    Park, Joonbum; Hershberger, John F.

    1994-02-01

    The kinetics of NCO reactions with hydrocarbon molecules were investigated using time-resolved infrared diode laser absorption spectroscopy. NCO was probed at 1905.6 cm -1, and HNCO reaction products were probed at 2280.1 cm -1. Rate constants at 296 K were measured to be HNCO was observed to be a major product channel for reactions with alkanes and for C 2H 2. For C 2H 2, HNCO is formed in negligible yield, indicating that addition—elimination is the primary mechanism active.

  6. VUV Photoionisation of hydrocarbon radicals

    Science.gov (United States)

    Alcaraz, C.; Noller, Bastian; Hemberger, Patrick; Fischer, Ingo; Gans, Bérenger; Boyé-Peronne, Séverine; Douin, Stéphane; Gauyacq, Dolorès; Soldi-Lose, Héloïse; Garcia, Gustavo

    2008-09-01

    Hydrocarbon radicals CxHy are constituents of various planetary atmospheres, in particular Titan, as a result of the methane photochemistry induced by the solar radiation. They contribute to the neutral chemistry, but are also important for the ionosphere through their photoionisation leading to their cations CxHy +. These cations are also produced by ion-molecule reactions starting from the reaction of the primary ions CH4 + and CH3 + which are created in the non-dissociative and dissociative photoionisation of CH4. This work aims at caracterizing the VUV photoionisation of small hydrocarbon radicals as a function of photon energy. The objective is to provide laboratory data for modelers on the spectroscopy, the thermochemistry, and the reactivity of the radicals and their cations. The hydrocarbon radicals are much less caracterized than stable molecules since they have to be produced in situ in the laboratory experiment. We have adapted at Orsay [1-3] a pyrolysis source (Figure 1) well suited to produce cold beams of hydrocarbon radicals to our experimental setups. Available now at Orsay, we have two new sources of VUV radiation, complementary in terms of tunability and resolution, that can be used for these studies. The first one is the DESIRS beamline [4] at the new french synchrotron, SOLEIL. The second one is the VUV laser developped at the Centre Laser de l'Université Paris-Sud (CLUPS) [5]. At SOLEIL, a photoelectron-photoion coincidence spectrometer is used to monitor the photoionisation on a large photon energy range. At the CLUPS, a pulsedfield ionisation (PFI-ZEKE) spectrometer allows studies at higher resolution on selected photon energies. The first results obtained with these new setups will be presented. References [1] Fischer, I., Schussler, T., Deyerl, H.J., Elhanine, M. & Alcaraz, C., Photoionization and dissociative photoionization of the allyl radical, C3H5. Int. J. Mass Spectrom., 261 (2-3), 227-233 (2007) [2] Schüßler, T., Roth, W., Gerber, T., Alcaraz, C. & Fischer, I., The vacuum ultraviolet photochemistry of radicals: C3H3 and C2H5. Phys. Chem. Chem. Phys., 7 (5), 819-825 (2005) [3] Schüßler, T., Deyerl, H. J., Dummler, S., Fischer, I., Alcaraz, C. & Elhanine, M., The vacuum ultraviolet photochemistry of the allyl radical investigated using synchrotron radiation J. Chem. Phys., 118 (20), 9077-80 (2003) [4] DESIRS, http://www.synchrotronsoleil. fr/portal/page/portal/Recherche/LignesLumiere/ DESIRS [5] CLUPS, http://www.clups.u-psud.fr/

  7. Abiogenic origin of petroleum hydrocarbons: Need to rethink exploration strategies

    Digital Repository Service at National Institute of Oceanography (India)

    Paropkari, A

    2008-01-01

    The origin of petroleum hydrocarbons is a matter of debate since its discovery. During last several decades it is firmly believed that the origin of petroleum hydrocarbons is 'biogenic' due to chemical similarity between the natural hydrocarbons...

  8. 21 CFR 172.884 - Odorless light petroleum hydrocarbons.

    Science.gov (United States)

    2010-04-01

    ...2009-04-01 true Odorless light petroleum hydrocarbons. 172.884 Section 172.884...Additives § 172.884 Odorless light petroleum hydrocarbons. Odorless light petroleum hydrocarbons may be safely used in food, in...

  9. 21 CFR 573.740 - Odorless light petroleum hydrocarbons.

    Science.gov (United States)

    2010-04-01

    ...2010-04-01 false Odorless light petroleum hydrocarbons. 573.740 Section 573.740...Listing § 573.740 Odorless light petroleum hydrocarbons. Odorless light petroleum hydrocarbons complying with § 172.884(a)...

  10. 21 CFR 178.3650 - Odorless light petroleum hydrocarbons.

    Science.gov (United States)

    2010-04-01

    ...2009-04-01 true Odorless light petroleum hydrocarbons. 178.3650 Section 178.3650...Aids § 178.3650 Odorless light petroleum hydrocarbons. Odorless light petroleum hydrocarbons may be safely used, as a...

  11. Existence forms and fraction mechanisms of radionuclides in the underground nuclear explosions zones on the hydrocarbon raw deposits

    International Nuclear Information System (INIS)

    Experimental data on concentrations and bearing forms of radionuclides in the oil, soils and natural waters samples collected in the underground nuclear explosions zones on the hydrocarbon raw deposits (Gezh, Osina and Middle Botuob deposits) were obtained. Effect of explosive and post-explosive processes, as well as the deposits exploitation regimes on radionuclide migration in the underground nuclear explosion zones were considered. It was established that in a number of cases the underground nuclear explosions cavities lost their impermeability. This leads to propagation of technogenous radionuclides outside the cavities boundaries. It is shown, that light hydrocarbon oil fraction collected on the different distance from explosion cavities is enriched with tritium, and the heavy fractions with 137Cs decay products. The methodic aspects of works on the radionuclide concentrations determination and its physico-chemical forms in the samples collected on the hydrocarbon raw deposits deposits are discussed

  12. Polynuclear aromatic hydrocarbons for fullerene synthesis in flames

    Science.gov (United States)

    Alford, J. Michael; Diener, Michael D.

    2006-12-19

    This invention provides improved methods for combustion synthesis of carbon nanomaterials, including fullerenes, employing multiple-ring aromatic hydrocarbon fuels selected for high carbon conversion to extractable fullerenes. The multiple-ring aromatic hydrocarbon fuels include those that contain polynuclear aromatic hydrocarbons. More specifically, multiple-ring aromatic hydrocarbon fuels contain a substantial amount of indene, methylnapthalenes or mixtures thereof. Coal tar and petroleum distillate fractions provide low cost hydrocarbon fuels containing polynuclear aromatic hydrocarbons, including without limitation, indene, methylnapthalenes or mixtures thereof.

  13. Hydrocarbon production with nuclear explosives

    International Nuclear Information System (INIS)

    The tremendous energy of nuclear explosives and the small dimensions of the explosive package make an ideal combination for drill-hole explosive emplacement in deep, thick hydrocarbon deposits. Potential applications exist in fracturing low permeability natural-gas and petroleum formations for stimulating production, fracturing oil shale to permit in situ retorting, and creating storage chimneys for natural gas, liquefied petroleum gas, petroleum, petroleum products, helium, and other fluids. Calculations show, for example, that less than 100 shots per year would be needed to stabilize the natural gas reserves to production ratio. Under the Government-industry Plowshare program, two experiments, Projects Gasbuggy and Rulison, were conducted to stimulate natural gas production from low-permeability formations. Incomplete information indicates that both were technically successful. Potential problems associated with the use of nuclear explosives for underground engineering applications are radioactive contamination, maximum yield limitations, high costs of detonating contained nuclear explosives, and adverse public opinion. Results at Project Gasbuggy and other considerations indicated that the problem of radioactive contamination was about as predicted and not an insurmountable one. Also, it was demonstrated that shots at adequate depths could be detonated without appreciable damage to existing surface and subsurface buildings, natural features, and equipment. However, costs must be reduced and the public must be better informed before these techniques can be widely used in field operations. On the basis of present knowledge, the potential of nuclear-explosive stimulation of hydrocarbon production appears good. Additional field experiments will be required to adequately explore that potential. (author)

  14. Thermal maturity history and implications for hydrocarbon exploration in the Catatumbo basin, Colombia

    International Nuclear Information System (INIS)

    A thermal model integrated with oil and gas geochemical study has been constructed for the Catatumbo basin, Colombia for provides petroleum system data for hydrocarbon exploration. The calibration of the thermal model with maturity data took into account a changing heat flow scheme which included a thermal increase towards the end of the Jurassic and another one in the early Eocene, associated with rifting events. Locally, active/generating source rocks are within the synclines axes. The hydrocarbon expulsion time for Cretaceous source rocks (Capacho and La Luna formations) started in the upper Paleocene-Eocene, while for the los Cuervos Formation the generation and expulsion started of 1 0 my. The petroleum expelled during the Paleocene-Miocene, were likely accumulated in structures formed since the end of the cretaceous, while the younger structures that resulted from the Andean orogen were charged by remigration from the older structures and additionally with the youngest lately generated hydrocarbons. The accumulations of hydrocarbons are mainly the result of generation and migration locally within the basin. The Catatumbo Basin contains thermogenic wet gases with different degrees of thermal maturity which varies from around 1,0 for 2,5 equivalent Ro. The highest degree of thermal evolution according to maturity indicators and thermal modeling is in the southern area, which is prospective for wet gas. The central and northern area appears more prospective for oilhern area appears more prospective for oil with minor amounts of gas

  15. ROR?t modulates macrophage recruitment during a hydrocarbon oil-induced inflammation.

    Science.gov (United States)

    Wu, Qi; Sun, Xin; Chi, Ruo; Xu, Long; Li, Xue; Feng, Jing; Chen, Huaiyong

    2013-01-01

    Hydrocarbon oils are often utilized as adjuvants in vaccines. In response to naturally occurring hydrocarbon oils, inflammation is initiated and persists with the continuous recruitment of immune cells such as macrophages and neutrophils. However, the mechanism underlying the chronic inflammation in response to hydrocarbon oils is not fully defined. In this study, we revealed an essential role of retinoid-related orphan receptor gamma t (ROR?t) in sustaining the recruitment of macrophages following pristane treatment. ROR?t absence resulted in the incompetent formation of mesenteric oil granulomas which may associate to a reduction in the migration of macrophages into the mesentery during pristane-induced inflammation. This is at least partially dependent on the expression of the monocyte chemoattractant protein-1 (MCP-1) in the mesentery and the decrease in the macrophage reservoir in the spleen. However, the absence of ROR?t had no impact on the recruitment of neutrophils to the mesentery after pristane treatment. Our data uncovered an important role of ROR?t in the recruitment of macrophages during hydrocarbon oil-induced chronic inflammation. PMID:24260235

  16. Distribution of hydrocarbons in fractured clay soils

    International Nuclear Information System (INIS)

    Surface or near surface spills of hydrocarbons such as gasoline and diesel often occur into clay soils which are fractured and unsaturated.. The distribution and extent of contamination must be determined prior to the development of remediation methods. The movement of the free phase hydrocarbon occurs primarily by infiltration into the fractures and the initial distribution of hydrocarbon in the soil is controlled by fracture geometry. Over time; however, significant changes in the distribution of the hydrocarbon occur. The dominant mechanism for long-term re-distribution of hydrocarbons is through diffusion and adsorption of the aqueous phase hydrocarbon into the matrix between the fractures. The implication of this change in hydrocarbon distribution is that different remediation schemes must be adopted at various times after the initial spill occurred. Double reservoir diffusion testing was undertaken for samples of re-compacted clay in order to define the coefficient of molecular diffusion and adsorption which control the rate at which the re-distribution of benzene would take place. Specific experimental and analytical protocols were developed for the testing of volatile organic chemicals. Estimates were made of the rate of re-distribution of hydrocarbon between the free-phase in the fracture and the aqueous phase in the matrix for a given fracture geometry. These estimates are compared to qualitative estimates of the rate of re-distribution as observed in typicae of re-distribution as observed in typical site investigations

  17. Contribution to radiolysis study of liquid hydrocarbons

    International Nuclear Information System (INIS)

    This work deals with radiolysis of liquid hydrocarbons. First, the radiochemical yields of various products are correlated with the theoretical bond energies, for some hydrocarbons. Several values of scavenging parameter ?sub(S) are calculated and the methods for these determinations are criticized. In the last part, we present a new method for the calculation of electron scavenging rate constants

  18. Chlorinated hydrocarbons in women with repeated miscarriages.

    OpenAIRE

    Gerhard, I.; Daniel, V.; Link, S.; Monga, B.; Runnebaum, B.

    1998-01-01

    This study was conducted to investigate a possible etiological role of chlorinated hydrocarbons in the pathogenesis of repeated miscarriages. The blood levels of chlorinated hydrocarbons [CHCs: pentachlorophenol, hexachlorocyclohexane, hexachlorobenzene, the dichlorodiphenyltrichloroethane (DDT) group, polychlorinated biphenyls] were determined in 89 women with repeated miscarriages, who were referred to the University Hospital of Obstetrics and Gynecology of Heidelberg for investigations bet...

  19. Mechanisms and modelling of gas migration from deep radioactive waste repositories

    International Nuclear Information System (INIS)

    This report discusses the mechanisms by which gas is able to migrate through the far-field. The mechanisms available are diffusion or advection of gas dissolved in groundwater or free gas phase flow as either bubbles or a continuous stream of gas. Modelling approaches adopted to assess the migration are (a) simple use of Darcy's law with an effective permeability to gas, (b) the development of a model based on the representation of the far-field rock as a bundle of capillaries with a suitable distribution of radii, and (c) the use of a numerical model of two-phase flow in porous media. Finally, surveys have been carried out of published work on gas escape from underground storage caverns and of literature relating to gas movement from underground hydrocarbon accumulations to determine whether these may be potential sources of data or understanding of underground gas migration relevant to that from deep waste repositories. (author)

  20. Secondary fuel delivery system

    Science.gov (United States)

    Parker, David M. (Oviedo, FL); Cai, Weidong (Oviedo, FL); Garan, Daniel W. (Orlando, FL); Harris, Arthur J. (Orlando, FL)

    2010-02-23

    A secondary fuel delivery system for delivering a secondary stream of fuel and/or diluent to a secondary combustion zone located in the transition piece of a combustion engine, downstream of the engine primary combustion region is disclosed. The system includes a manifold formed integral to, and surrounding a portion of, the transition piece, a manifold inlet port, and a collection of injection nozzles. A flowsleeve augments fuel/diluent flow velocity and improves the system cooling effectiveness. Passive cooling elements, including effusion cooling holes located within the transition boundary and thermal-stress-dissipating gaps that resist thermal stress accumulation, provide supplemental heat dissipation in key areas. The system delivers a secondary fuel/diluent mixture to a secondary combustion zone located along the length of the transition piece, while reducing the impact of elevated vibration levels found within the transition piece and avoiding the heat dissipation difficulties often associated with traditional vibration reduction methods.

  1. Radiation damages of organic materials at 4 K: an ESR study of polyethylene and related hydrocarbons

    International Nuclear Information System (INIS)

    To characterize the radiation damages produced at 4 K in polyethylene and related hydrocarbons, a series of studies have been carried out by using electron spin resonance spectroscopy. It has been found that the local concentration of radiation induced paramagnetic species is considerably higher in the irradiation at 4 K than that at 77 K. The causes of this irradiation temperature effect on the spatial distribution of radicals have been extensively studied. It is suggested that the suppression of hydrogen atom migration and the reactivity of hydrogen atoms at 4 K play an important role in the low temperature radiation damages of saturated hydrocarbons. In the present paper the results previously and newly obtained are surveyed and discussed as a whole. (author)

  2. Mathematical modelling of the interactions between thermal cracking and migration in the formation of oil and gas

    Energy Technology Data Exchange (ETDEWEB)

    Ungerer, P.; Espitalie, J.; Behar, F.; Eggen, S.

    1988-08-30

    We present here a kinetic model describing the composition of oil and gas generated by the thermal breakdown of sedimentary organic matter. This model is calibrated on pyrolysis experiments performed under both open and closed systems. It considers four hydrocarbon fractions (C 15+, C6-C14, C2-C5, methane) and it accounts for the considerable importance of migration, in that: a rapid expulsion of petroleum from the source rock favors the formation of liquid hydrocarbons, whereas gas dominates in the case of late expulsion.

  3. "Global Migration Patterns" Lesson Plan

    Science.gov (United States)

    The United States has often been referred to as a "nation of immigrants." While immigration has historically been the country's foundation, immigration continues to shape the structure and composition of the population. The majority of migrants move in response to economic pressures, but some migrants—called refugees—move because of fear. Recognizing their story is also an important part of understanding international migration. The objectives of this course are to understand immigration to the United States, to identify major international migration streams, to evaluate the impact of migration on U.S. population structure, to explain the impact of major refugee movements on both source and host countries.

  4. Full wavefield migration: utilization of multiples in seismic migration:

    OpenAIRE

    Berkhout, A. J.; Verschuur, D. J.

    2012-01-01

    The next generation migration technology considers multiple scattering as vital information, allowing the industry to generate significantly better images of the subsurface. The proposed full wavefield algorithm (FWM) makes use of two-way wave theory that is formulated in terms of one-way wavefields. We show that the current migration algorithms for primary reflections can be easily extended to handle multiple scattering as well

  5. Basic neutronics. Neutrons migration

    International Nuclear Information System (INIS)

    This article presents the basic neutronics necessary for the understanding of the operation of the different types of nuclear reactors: 1 - introduction to neutronics: principle of fission chain reactions, fast neutron reactors and thermal neutron reactors, capture, neutron status, variations with the reactor lattices; 2 - Boltzmann equation: neutrons population, neutrons migration, characterization of neutrons population and reactions, integral form of the Boltzmann equation, integral-differential form, equivalence between the two forms; 3 - reactor kinetics: fast neutrons and delayed neutrons, kinetic equations in punctual model, Nordheim equation, reactivity jumps, reactivity ramp; 4 - diffusion equation: local neutron status, Fick's law, diffusion equation, initial, boundary and interface conditions, nuclei in infinite and homogenous medium, some examples of solutions, developments in Eigenmodes; 5 - one-group theory: equation of the 'one-group - diffusion' theory, critical condition of the naked and homogenous reactor, critical condition of a reactor with reflectors, generalizations; 6 - neutrons moderation: different moderation mechanisms, elastic shock laws, moderation equation, some examples of solutions; 7 - resonance absorption of neutrons: advantage of the discontinuous moderation character, advantage of an heterogenous disposition, classical formula of the anti-trap factor in homogenous and heterogenous situation; 8 - neutrons thermalization: notions of th8 - neutrons thermalization: notions of thermalization mechanisms, thermalization equation, Maxwell spectrum, real spectrum, classical formula of the thermal utilisation factor, classical formula of the reproduction factor, moderation optimum. (J.S.)

  6. Migration and Capillary Formation

    Directory of Open Access Journals (Sweden)

    TrachetteJackson

    2013-05-01

    Full Text Available Vascular endothelial growth factor (VEGF is the most studied family of soluble secreted mediators of endothelial cell migration, survival and proliferation. VEGF exerts its function by binding to specific tyrosine kinase receptors on the cell surface and transducing the effect through downstream signaling. In order to study the influence of VEGF binding on endothelial cell motion, we develop a hybrid model of VEGF-induced angiogenesis, based on the theory of reinforced random walks. The model includes the chemotactic response of endothelial cells to angiogenic factors bound to cell-surface receptors, rather than approximating this as a function of extracellular chemical concentrations. This allows us to capture biologically observed phenomena such as activation and polarization of endothelial cells in response to VEGF gradients across their lengths, as opposed to extracellular gradients throughout the tissue. We also propose a novel and more biologically reasonable functional form for the chemotactic sensitivity of endothelial cells, which is also governed by activated cell surface receptors. This model is able to predict the threshold level of VEGF required to activate a cell to move in a directed fashion as well as an optimal VEGF concentration for motion. Model validation is achieved by comparison of simulation results directly with experimental data.

  7. Migrations et relations internationales Migration and international relations. The pitfalls of managing international migration multilaterally

    Directory of Open Access Journals (Sweden)

    Hélène Thiollet

    2010-12-01

    Full Text Available Les migrations internationales sont aujourd’hui un des enjeux majeurs de la gouvernance globale. Elles restent pourtant l’objet de politiques régaliennes où dominent les accords bilatéraux sans que s’impose un régime de gestion multilatéral. Les migrations sont une des pierres d’achoppement du multilatéralisme et leur gestion est revendiquée par les États comme une dimension inaliénable de leur souveraineté (économique, territoriale…. Les institutions multilatérales tentent de proposer des modalités de gouvernance multilatérale des migrations comme phénomène social global. À l’Onu, le Haut commissariat aux réfugiés (Hcr s’occupe des réfugiés et l’Organisation internationale du travail (Oit des migrants en leur qualité de travailleurs. La Banque mondiale et le Fmi sont particulièrement actifs sur la question des migrations et des transferts financiers qui les accompagnent alors que l’Unicef s’intéresse aux conséquences sociales de la mobilité sur les familles dans les pays d’origine ou d’accueil. L’Organisation internationale des migrations travaille quant à elle en marge de l’Onu. L’Onu n’est pas parvenu à imposer la Convention sur les droits des migrants de 1990 et ne parvient pas à faire émerger une ligne d’action collective dans l’arène multilatérale sur la question migratoire. Pourtant, dans la sphère onusienne et au-delà, les organisations internationales négocient l’émergence d’une agence spécialisée dans les migrations. À partir de la stratégie historique du Hcr dans le champ multilatéral et d’une innovation juridique récente – le concept de « migrations mixtes » –, on décrit une des tentatives de gestion juridique de la mobilité forcée et volontaire. En 2006, le concept émerge avec l’expérience des migrations sub-sahariennes à travers la Méditerranée. On s’intéresse ici à son utilisation dans le cas de migrations depuis la corne de l’Afrique vers le Yémen. Le concept de « migrations mixtes » permet d’observer les prémisses de la remise en question de la partition entre réfugiés et migrants économiques. Cette analyse nous permet de mettre en lumière les apories contemporaines des conditions juridiques et statutaires de la mobilité et les réponses pragmatiques qui y sont apportées. À partir de sa compétence de terrain sur les populations réfugiées et d’innovation organisationnelles récentes, le Hcr se positionne dans le champ politique international comme gestionnaire potentiel de la mobilité internationale face à l’Oit ou à une agence non-onusienne comme l’Oim.Today, one of the biggest issues facing global governance is international migration. It is nevertheless dominated by national policy and bilateral agreements, and lacks a multilateral management system. Indeed, migration is one of the stumbling blocks of multilateralism, because most countries consider migration management is key to national sovereignty (in economic and territorial terms. Multilateral institutions attempt to suggest multilateral migration governance mechanisms as a global social phenomenon. At the UN, the High Commission on Refugees (UNHCR was created to deal with refugee issues, and the International Labour Organisation (ILO for migrant workers. The World Bank and the International Monetary Fund (IMF are very active in issues affecting migrants and remittances, while UNICEF focuses on the social consequences of this mobility on families in home and host countries. The International Organisation for Migration (IOM works on the fringes of the UN. The UN was unable to impose the Convention on the Rights of Migrants in 1990, and has had difficulty in developing a joint programme of action for the multilateral management of migration. Nevertheless, on the UN level and above, international organisations are negotiating the creation of an agency specialising in migration. Using the HCR’s past multilateral strategy and a recent legal innovation – the concept of mixed migration – we descr

  8. La hydrogeology en la traditional mining of hydrocarbons, mining new

    International Nuclear Information System (INIS)

    Is presented from the point of view of Geosciences, an approach torelations between hydrogeology and mining activities, including those of traditional non - metal deposits of ores and rocks application (underground or open pit), the so-called ''modern mining'' (pickles) and hydrocarbons. Within the traditional mining, hydrogeology participates decisively several aspects, both those related to the feasibility of the projects, water supply for the stage of exploration and exploitation, mineraloductos ácueosand mine operations, such as environmental protection of water resources. In the ''modern mining'' groundwater acquires true character mena when it comes to the use of natural brines, and subject when they are generated by injecting water into an aquifer medium. In the case of hydrocarbons, the spectrum is broader participation at the stage of exploration and exploitation, where the hydrogeology is critical to providing water to camps and processes as well as operations secondary recovery, consumers strongly. From the perspective of environmental protection, are the main protagonists of groundwater the impacts of production, but also the phases are transportation, processing and marketing. They are used in the presentation of case examples of Argentina and Chile, some reflections on the need for an appropriate regulatory framework, especially addressed to Uruguay, and information to protect the population activity production of an unfair detriment, when mining is done responsibly

  9. Fluid migration studies in salt

    International Nuclear Information System (INIS)

    This discussion will be limited to the migration of water trapped in the rock salt under the influence of the heat field produced by nuclear waste. This is of concern because hypotheticl scenarios have been advanced in which this fluid movement allows radionuclides to escape to the biosphere. While portions of these scenarios are supported by observation, none of the complete scenarios has been demonstrated. The objectives of the present fluid migration studies are two-fold: 1. determine the character of the trapped fluid in terms of quantity, habitat and chemical constituents; and 2. define the mechanisms that cause the fluid to migrate toward heat sources. Based on the observations to date, fluid migration will not have a major impact on repository integrity. However, the above objectives will be pursued until the impacts, if any, can be quantified

  10. The migration challenge for PAYG.

    Czech Academy of Sciences Publication Activity Database

    Aslanyan, Gurgen

    2014-01-01

    Ro?. 27, ?. 4 (2014), s. 1023-1038. ISSN 0933-1433 Institutional support: RVO:67985998 Keywords : public pensions * PAYG * unskilled migration Subject RIV: AH - Economics Impact factor: 1.470, year: 2013

  11. The migration challenge for PAYG.

    Czech Academy of Sciences Publication Activity Database

    Aslanyan, Gurgen

    2014-01-01

    Ro?. 27, ?. 4 (2014), s. 1023-1038. ISSN 0933-1433 Institutional support: PRVOUK-P23 Keywords : public pensions * PAYG * unskilled migration Subject RIV: AH - Economics Impact factor: 1.470, year: 2013

  12. MRI of neuronal migration disorders

    International Nuclear Information System (INIS)

    Twenty-one MRI examinations of the brain were performed in 19 children with neuronal migration disorders. Multiplanar oriented spin-echo sequences were on a scanner with 1.5 T. In 8 children we performed an additional turbo-inversion recovery (TIR) sequence. Results of sonography or CT from five children were compared with MRI scans. Using the actual nomenclature, we found the following migration disorders: Lissencephaly (n=6), cobblestone lissencephaly with Walker-Warbung syndrome (WWS) (n=2), polymicrogyria and schizencephaly (n=2), focal heterotopia (n=5), diffuse heterotopie (n=2) and hemimegalencephaly (n=2). MRI was superior to CT and sonography in all children. Except for the two boys with WWS, the TIR sequence was the best to demonstrate the changes in migration disorder because of the high contrast between gray and white matter. We demonstrate the characteristic features of the different migration disorders and compare them with the existing literature. (orig.)

  13. Teaching secondary mathematics

    CERN Document Server

    Rock, David

    2013-01-01

    Solidly grounded in up-to-date research, theory and technology,?Teaching Secondary Mathematics?is a practical, student-friendly, and popular text for secondary mathematics methods courses. It provides clear and useful approaches for mathematics teachers, and shows how concepts typically found in a secondary mathematics curriculum can be taught in a positive and encouraging way. The thoroughly revised fourth edition combines this pragmatic approach with truly innovative and integrated technology content throughout. Synthesized content between the book and comprehensive companion websi

  14. The Fate of Hydrocarbon Pollution in Kebnekaise, Arctic Sweden

    Science.gov (United States)

    Rosqvist, G. N.; Jarjso, J.; Clason, C.; Jansson, P.; Karlin, T.

    2013-12-01

    A C-130J-30 Super Hercules plane crashed into the west-facing wall of the Kebnekaise mountain (2103 m), Arctic Sweden, on March 15th 2012. When starting from Evenes, Narvik, Norway, the aircraft had 14100 l fuel, 50 l hydraulic oil and 170 l motor oil onboard. Best estimates are that at least 12 000 l of fuel was sprayed over the mountain most of which was buried together with the wreck in a huge snow avalanche that was triggered by the impact in a NW facing cirque on Rabots glacier between ca 1600 and 2000 m. Fuel decontamination was not possible because of the extreme impact site conditions. The Hercules airplane was fueled with JET A-1 which is a hydrocarbon product in the Kerosene/Jet Fuel category consisting of sweetened kerosene and hydrotreated light distillates. The major components of all 'kerosene's' are branched- and straight-chain paraffins and naphthenes (cycloparaffins or cycloalkanes), which normally account for 70% by volume. Aromatic hydrocarbons, such as alkyl benzenes (single ring) and alkylnaphthalenes (double ring) do not exceed 25 % by volume of kerosene. The fuel also contains polycyclic aromatic hydrocarbons (PAH), but in very small volumes compared to the major components. The physical and chemical properties of each component (or block) of the hydrocarbon mixture influence its migration rate and fate. Some components of the fuel will volatilize, some are soluble in water but the vast majority are non-soluble. Although the solubility of these so called Light Nonaqueous Phase Liquids (LNAPL) in water is small they are highly toxic. We need to consider transport of the soluble components of the LNAPL in the melt-water, and transport of the non-soluble components with the melt-water system. Transport and storage can occur through and in snow (or firn), crevasses, and cavities on, in or under the glacier. Storage in, and contamination of, basal sediments, located below the glacier, or pro-glacial sediments, in front of the glacier are also possible. We have traced and determined the chemical evolution of the polluted snow and firn at the source zone during two summer melt seasons (2012 and 2013). We have estimated the transit time of polluted melt-water through the glacier by dye-trace experiments. We have assessed the potential of biodegradation by microorganisms and we monitor possible eco-hydrological effects in streams and lakes. Results will be used to estimate the full recovery time of the glacier and pro-glacial environment. This project provides a unique opportunity to formulate and test critical hypotheses regarding hydrocarbon spreading in a polar environment. We are today surprisingly unprepared to answer the basic question on how such pristine environments are influenced by hydrocarbon pollution. However, with the increasing pressures in polar environments, there is a dire need and a rare opportunity to now create such knowledge base.

  15. Palaearctic-African Bird Migration

    DEFF Research Database (Denmark)

    Iwajomo, Soladoye Babatola

    2013-01-01

    Bird migration has attracted a lot of interests over past centuries and the methods used for studying this phenomenon has greatly improved in terms of availability, dimension, scale and precision. In spite of the advancements, relatively more is known about the spring migration of trans-Saharan migrants than autumn migration. Information about the behavior and interactions of migrants during the nonbreeding season in sub-Saharan Africa is also scarce for many species. Furthermore, very little is known about intra-African migration. This thesis summarizes my research on the autumn migration of birds from Europe to Africa and opens up the possibility of studying intra-African migration. I have used long-term, standardized autumn ringing data from southeast Sweden to investigate patterns in biometrics, phenology and population trends as inferred from annual trapping totals. In addition, I investigated the relationship between the timing of autumn migration and climatic variations at local and spatial scale. The first three papers focused on speciesspecific analysis. In them I described the age-specific patterns in biometrics, phenology and migration strategies as well as trends in the population of the species. The papers show that adult and juvenile birds can use different migration strategies depending on time of season and prevailing conditions. Also, the fuel loads of some individuals were theoretically sufficient for a direct flight to important goal area, but whether they do so is still unknown. The fourth paper and one manuscript investigate the behavior of garden warblers Sylvia borin, during the non-breeding season in Nigeria. The first paper shows that the species also utilizes habitats south of the savannah region, presumably on its way to the final goal area. Individuals also molt their flight feathers at this location and intraspecific interactions are non-aggressive. The second manuscript investigates whether variations in the timing of migration of wader species at a stopover site in southeast Sweden is influence by local or regional climatic variables. The manuscript reveals that both factors may be important and that species breeding close to Ottenby and those breeding in the arctic may be affected by either of the two variables. In addition, breeding success is probably an important factor influencing timing of migration. The third manuscript compares the breeding possibilities between two related cuckoo species using home range estimates derived from satellite telemetry data. The influence host species availability, foraging habitats are discussed.

  16. Effective Viscosity of Confined Hydrocarbons

    Science.gov (United States)

    Sivebaek, I. M.; Samoilov, V. N.; Persson, B. N. J.

    2012-01-01

    We present molecular dynamics friction calculations for confined hydrocarbon films with molecular lengths from 20 to 1400 carbon atoms. We find that the logarithm of the effective viscosity ?eff for nanometer-thin films depends linearly on the logarithm of the shear rate: log??eff=C-nlog???, where n varies from 1 (solidlike friction) at very low temperatures to 0 (Newtonian liquid) at very high temperatures, following an inverse sigmoidal curve. Only the shortest chain molecules melt, whereas the longer ones only show a softening in the studied temperature interval 0

  17. Preparation of aromatic hydrocarbon monocrystals

    International Nuclear Information System (INIS)

    This report explains the technique developed and used for the production of organic monocrystals, necessary for the detection of ? radiation. The Bridgman process has been used. A glass bulb containing the substance to be crystallized passes through a vertical thermo-regulated furnace maintained slightly above the fusion point of the substance. The bottom of the bulb has a conical section which ends with a thin capillary in order to obtain a single crystal nucleus. This method has been implemented to several hydrocarbons (naphthalene, anthracene, stilbene, tolan, tetraphenylethylene, tetra-phenyl-butadiene). The report describes successively: the furnaces, the process used for the filling of the bulbs, the degassing of the products, and for each compound, the details of the preparation and purification and the size of the obtained crystals. (J.S.)

  18. Distribution of hydrocarbon-utilizing microorganisms and hydrocarbon biodegradation potentials in Alaskan continental shelf areas

    International Nuclear Information System (INIS)

    Hydrocarbon-utilizing microogranisms were enumerated from Alaskan continental shelf areas by using plate counts and a new most-probable-number procedure based on mineralization of 14C-labeled hydrocarbons. Hydrocarbon utilizers were ubiquitously distributed, with no significant overall concentration differences between sampling regions or between surface water and sediment samples. There were, however, significant seasonal differences in numbers of hydrocarbon utilizers. Distribution of hydrocarbon utilizers within Cook Inlet was positively correlated with occurrence of hydrocarbons in the environment. Hydrocarbon biodegradation potentials were measured by using 14C-radiolabeled hydrocarbon-spiked crude oil. There was no significant correlation between numbers of hydrocarbon utilizers and hydrocarbon biodegradation potentials. The biodegradation potentials showed large seasonal variations in the Beaufort Sea, probably due to seasonal depletion of available nutrients. Non-nutrient-limited biodegradation potentials followed the order hexadecane > naphthalene >> pristane > benzanthracene. In Cook Inlet, biodegradation potentials for hexadecane and naphthalene were dependent on availability of inorganic nutrients. Biodegradation potentials for pristane and benzanthracene were restricted, probably by resistance to attack by available enzymes in the indigenous population

  19. Interstitial leukocyte migration in vivo

    OpenAIRE

    Lam, Pui-ying; Huttenlocher, Anna

    2013-01-01

    Rapid leukocyte motility is essential for immunity and host defense. There has been progress in understanding the molecular signals that regulate leukocyte motility both in vitro and in vivo. However, a gap remains in understanding how complex signals are prioritized to result in directed migration, which is critical for both adaptive and innate immune function. Here we focus on interstitial migration and how external cues are translated into intracellular signaling pathways that regulate leu...

  20. Zero Overhead Java Thread Migration

    OpenAIRE

    Bouchenak, Sara; Hagimont, Daniel

    2002-01-01

    The wide diffusion of Java is partly due to its mechanisms for mobile computing. Java provides most of the functions required to implement mobile applications, essentially code mobility (i.e., dynamic class loading) and data mobility (i.e., object serialization). However, Java does not provide any mechanism for the mobility of the computation (i.e., threads migration). Several projects have addressed the issue of Java thread migration- , e.g.,Sumatra, Wasp, JavaGo, Brakes, CIA. Most of these ...

  1. Macrostabilization of the Migration Phenomenon

    OpenAIRE

    Cristina Burghelea; Anda Gheorghiu; Cristiana Tindeche; Anca Gheorghiu; Nicolae Mihailescu

    2014-01-01

    MacLabour migration is a present phenomenon in the European Union. This phenomenon takes over the entire European continent, but especially in the EU countries. The labor market in Europe is increasingly affected by population aging. Economic differences between European countries make workforce in developing countries to move to developed countries where they find it easier to work and receive higher remuneration than in their home countries. This article tracks labor migration from/to EU, e...

  2. SSI, labor supply, and migration

    OpenAIRE

    Neumark, David; Powers, Elizabeth T.

    2005-01-01

    The Supplemental Security Income (SSI) program in the United States creates incentives for potential aged recipients to reduce labor supply prior to becoming eligible, and our past research finds that older men likely to be eligible for SSI at age 65 reduce their labor supply in the years immediately before the age of eligibility. However, given the dramatic supplementation of SSI benefits in some states, a migration response to these benefits cannot be dismissed, and migration that is associ...

  3. Gender and Migration in Sudan

    OpenAIRE

    BABIKER, Mohamed Abdelsalam

    2011-01-01

    Abstract This paper focuses on legal issues related to gender and migration in Sudan and highlights rules which specifically focus on women, and also rules and practices whose implementation mainly concerns women. In this context, the paper examines migration rules in Sudan as a host, origin and transit country of female migrants by looking at key issues such as family reunification, personal laws or personal status, asylum rights and refugee protection, protection of vulnerable persons o...

  4. Calcium Flickers Steer Cell Migration

    OpenAIRE

    Wei, Chaoliang; Wang, Xianhua; Chen, Min; Ouyang, Kunfu; Song, Long-sheng; Cheng, Heping

    2008-01-01

    Directional movement is a property common to all cell types during development and is critical to tissue remodelling and regeneration after damage1–3. In migrating cells, calcium plays a multifunctional role in directional sensing, cytoskeleton redistribution, traction force generation, and relocation of focal adhesions1, 4–7. Here we visualise, for the first time, high-calcium microdomains (“calcium flickers”), and their patterned activation in migrating fibroblasts. Calcium flicker ...

  5. Return Migration and Working Choices

    OpenAIRE

    Tani, Massimiliano; Mahuteau, Ste?phane

    2008-01-01

    This paper uses the recent survey carried out in the framework of the MIREM project on returnees to Algeria, Morocco and Tunisia and studies the duration of emigration and the labour force status upon returning. The results suggest that age and the year of emigration play a central role in the migration decision, but they do not support the hypothesis that the duration of migration is determined by the desired labour market status upon returning home.

  6. The financial losses from the migration of nurses from Malawi

    Directory of Open Access Journals (Sweden)

    Muula Adamson S

    2006-11-01

    Full Text Available Abstract Background The migration of health professionals trained in Africa to developed nations has compromised health systems in the African region. The financial losses from the investment in training due to the migration from the developing nations are hardly known. Methods The cost of training a health professional was estimated by including fees for primary, secondary and tertiary education. Accepted derivation of formula as used in economic analysis was used to estimate the lost investment. Results The total cost of training an enrolled nurse-midwife from primary school through nurse-midwifery training in Malawi was estimated as US$ 9,329.53. For a degree nurse-midwife, the total cost was US$ 31,726.26. For each enrolled nurse-midwife that migrates out of Malawi, the country loses between US$ 71,081.76 and US$ 7.5 million at bank interest rates of 7% and 25% per annum for 30 years respectively. For a degree nurse-midwife, the lost investment ranges from US$ 241,508 to US$ 25.6 million at 7% and 25% interest rate per annum for 30 years respectively. Conclusion Developing countries are losing significant amounts of money through lost investment of health care professionals who emigrate. There is need to quantify the amount of remittances that developing nations get in return from those who migrate.

  7. Expression of Wnts in the developing murine secondary palate

    OpenAIRE

    Warner, Dennis R; SMITH, HENRY S.; Webb, Cynthia L; Greene, Robert M.; Pisano, M. Michele

    2009-01-01

    Morphogenesis of the mammalian secondary palate requires coordination of cell migration, proliferation, differentiation, apoptosis and synthesis of extracellular matrix molecules by numerous signal transduction pathways. Recent evidence suggests a role for members of the Wnt family of secreted cytokines in orofacial development. However, no study has systematically or comprehensively examined the expression of Wnts in embryonic orofacial tissue. We thus conducted a survey of the expression of...

  8. Migration and Security of States

    Directory of Open Access Journals (Sweden)

    Cristian Jura

    2012-05-01

    Full Text Available The main topic of this article is represented by an attempt to encounter an answer to the questionwhether there is any connection between migration/minorities and security and how do they mutuallyinfluence. Pursuant to the analyses performed during the last years, we may definitely state that there is abiunivoque connection between migration/minorities and security. The migration/minorities may influencesecurity positively or negatively. Both states are influenced, the state they are leaving, and the state where theyare to settle. I have chosen to select in parallel two concepts: migration and minorities. The scientific groundthat determined me to decide to use such an approach is that migrants, sooner or later, turn into groups thatshare the same values, the same culture, the same traditions, the same language etc. Therefore, the migrantsturn into a minority living on the territory of the state where they have migrated. Practically, migration may bedefined by the movement of an important number of individuals, but, as these groups of individuals settle,they turn into minorities.

  9. Investigation on nuclide migration behaviors

    International Nuclear Information System (INIS)

    In this study, we investigated the properties of geochemical reactions and sorption of high-level radionuclides and highly-mobile radionuclides in deep geological disposal environments. We also analyzed the dissolution properties of pyro wastes and constructed databases for the geochemical reactions and sorption for the safety assessment of HLW disposal. Technologies for measuring diffusion depths of radionuclides through fracture surfaces and rock matrix were developed in KURT conditions and their diffusion properties were analyzed and evaluated. The combined reactions of radionuclide/mineral/microbe in deep disposal environments were investigated and the effects of microbe on the radionuclide migration and disposal system behaviors were evaluated. In-situ solute migration system and on-line monitoring system were installed in KURT and the migration and retardation behaviors of various solutes and their interaction with fracture-filling materials were investigated. Basic properties of KURT groundwater colloids were analyzed using various methods. In addition, in-situ colloid migration experiments through a rock fracture were carried out and the developed migration model was verified. We have participated in Colloid Formation and Migration (CFM) international joint project in GTS and obtained reliability for our research results by comparing research results each other

  10. Using supercritical fluids to refine hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Yarbro, Stephen Lee

    2015-06-09

    A system and method for reactively refining hydrocarbons, such as heavy oils with API gravities of less than 20 degrees and bitumen-like hydrocarbons with viscosities greater than 1000 cp at standard temperature and pressure, using a selected fluid at supercritical conditions. A reaction portion of the system and method delivers lightweight, volatile hydrocarbons to an associated contacting unit which operates in mixed subcritical/supercritical or supercritical modes. Using thermal diffusion, multiphase contact, or a momentum generating pressure gradient, the contacting unit separates the reaction products into portions that are viable for use or sale without further conventional refining and hydro-processing techniques.

  11. Improved hydrocarbon potentials for sputtering studies

    Energy Technology Data Exchange (ETDEWEB)

    Kent, P. [Oak Ridge National Laboratory (ORNL); Dadras, Mostafa Jonny [ORNL; Krstic, Predrag S [ORNL

    2011-01-01

    We refit the REBO hydrocarbon potentials by reparameterizing the bond lengths and energies of hydrocarbons with recent data, using systematic addition of the parameters of all hydrocarbons C{sub x}D{sub y} with x equal or less than four. In addition we also refit the short-distance potentials to reproduce a repulsive ZBL term. To test the improved potential, we performed large scale molecular dynamics calculations of amorphous deuterated carbon bombarded by deuterium, and compare our results with data obtained using the REBO potential as well as with recent experiments.

  12. Biodegradation of hydrocarbons from a refinery spill

    International Nuclear Information System (INIS)

    The biodegradation of several crude oil wastes from an oil refinery spill, was studied. Crude oil was spilled onto soil; with time, only the higher boiling point hydrocarbons remained as residue. Samples of this highly weathered hydrocarbon mixture were suspended in water to which Finasol OSR 51 dispersant was added in order to enhance dispersion. Also, certain microorganisms and a degradation accelerator, were both added to accelerate degradation. Each compound was identified by CG/FID. Daily records were kept of the concentration of hydrocarbons, and the percent degradation. Tables showing the degradation percentages achieved by each compound of the crude left over after several days, are included. 4 refs., tabs., 1 fig

  13. Biodegradation of hydrocarbons from a refinery spill

    Energy Technology Data Exchange (ETDEWEB)

    Bergueiro-Lopez, J.R.; Serra-Socias, F.; Moreno-Garcia-Luengo, S.; Morales-Correas, N.; Dominguez-Laseca, F. [Universidad de las Islas Baleares (Spain)

    1996-09-01

    The biodegradation of several crude oil wastes from an oil refinery spill, was studied. Crude oil was spilled onto soil; with time, only the higher boiling point hydrocarbons remained as residue. Samples of this highly weathered hydrocarbon mixture were suspended in water to which Finasol OSR 51 dispersant was added in order to enhance dispersion. Also, certain microorganisms and a degradation accelerator, were both added to accelerate degradation. Each compound was identified by CG/FID. Daily records were kept of the concentration of hydrocarbons, and the percent degradation. Tables showing the degradation percentages achieved by each compound of the crude left over after several days, are included. 4 refs., tabs., 1 fig.

  14. Music and Migration: A Transnational Approach

    OpenAIRE

    Nadia Kiwan; Ulrike Hanna Meinhof

    2011-01-01

    This special issue on the theme of Music and Migration addresses the highly topical theme of migration and the vitality of “cultural diasporas” through the prism of migrating musicians and migrating musical forms. All nine original articles, including our own, engage with broader questions of how new modes of mobility and sociality are borne out of the social, cultural, historical and political interfaces between migration and music. Through a transnational, comparative and multi-level ap...

  15. Infrared Spectra of Polycyclic Aromatic Hydrocarbons (PAHs)

    Science.gov (United States)

    Bauschlicher, Charles W., Jr.; Bakes, E. L. O.

    2000-01-01

    We have computed the synthetic infrared spectra of some polycyclic aromatic hydrocarbons containing up to 54 carbon atoms. The species studied include ovalene, circumcoronene, dicoronylene, and hexabenzocoronene. We report spectra for anions, neutrals, cations, and multiply charged cations.

  16. Collision data involving hydro-carbon molecules

    International Nuclear Information System (INIS)

    Hydro-carbon molecules are abundantly produced when graphites are used as internal wall materials of hydrogen plasmas and strongly influence properties of low temperature plasmas near the edges as well as those of high temperature plasmas at the center. In this report, following simple description of the production mechanisms of hydro-carbon molecules under the interactions between graphite and hydrogen plasma, the present status of collision data for hydro-carbon molecules by electron impact is discussed and the relevant data are summarized in a series of figures and tables. It should also be noted that, in addition to fusion plasmas, these hydrocarbon data compiled here are quite useful in other applications such as plasma chemistry and material processing. (author)

  17. [Biodegradation of oil hydrocarbons by Candida yeast].

    Science.gov (United States)

    Rusyn, I B; Moroz, O M; Karabyn, V V; Kulachkovs'ki?, O R; Hudz', S P

    2003-01-01

    Capability of 14 yeast species to utilize oil hydrocarbons has been analyzed. All strains utilized oil hydrocarbons as a single carbon source. Four strains-destructors that are characterized by higher growth in the presence oil in cultivation medium have been chosen among them. Peroxisomes participation in utilization of oil hydrocarbons by strains-destructors has been shown. Availability of peroxisome key enzymes are characteristic of these strains grown in cultivation medium with oil. Numerous peroxisomes available in the cells of some strains grown in oil cultivation medium have been demonstrated. Utilization of a wide spectrum of oil hydrocarbons has been revealed in all four strains. Two strains are promising to be used for environment purification from oil pollution. PMID:15077547

  18. Using microorganisms to aid in hydrocarbon degradation

    International Nuclear Information System (INIS)

    Aliphatic hydrocarbons are threatening the potable water supply and the aquatic ecosystem. Given the right microbial inhabitant(s), a large portion of these aliphatic hydrocarbons could be biodegraded before reaching the water supply. The authors' purpose is to isolate possible oil-degrading organisms. Soil samples were taken from hydrocarbon-laden soils at petroleum terminals, a petroleum refinery waste-treatment facility, a sewage-treatment plant grease collector, a site of previous bioremediation, and various other places. Some isolates known to be good degraders were obtained from culture collection services. These samples were plated on a 10w-30 multigrade motor oil solid medium to screen for aliphatic hydrocarbon degraders. The degrading organisms were isolated, identified, and tested (CO2 evolution, BOD, and COD) to determine the most efficient degrader(s). Thirty-seven organisms were tested, and the most efficient degraders were Serratia marcescens, Escherichia coli, and Enterobacter agglomerans

  19. NIST Hydrocarbon Spectral Database - SRD 115

    National Institute of Standards and Technology, Department of Commerce — This database contains the rotational spectral lines observed and reported in the open literature for 91 hydrocarbon molecules through September 1987. The isotopic...

  20. Liquid hydrocarbons probable under Ross Sea

    Science.gov (United States)

    Cooper, A. K.; Davey, F.J.; Hinz, K.

    1988-01-01

    Thick glacial strata, which have no source-rock potential, cover the Ross Sea. If these strata persist to great depths, then hydrocarbon-generation prospects will be poor. Deeply buried strata within Ross Sea rift-grabens, if like other Gondwana rift-deposits, could have good potential for hydrocarbon generation. Current hydrocarbon assessments of the Ross Sea and adjacent areas must be considered highly speculative because the deeply buried rift(?) strata have not been sampled in situ. The assessment of the Ross Sea relies on geophysical/geologic data, two-stage rift models, and data from formerly nearby Gondwana rift-basins. We conclude that conditions favorable for hydrocarbon generation and entrapment are likely throughout the Ross Sea, and especially in the Victoria Land basin, if adequate source beds exist. -Authors

  1. International parental migration and the psychological well-being of children in Ghana, Nigeria, and Angola.

    Science.gov (United States)

    Mazzucato, Valentina; Cebotari, Victor; Veale, Angela; White, Allen; Grassi, Marzia; Vivet, Jeanne

    2015-05-01

    When parents migrate, leaving their children in the origin country, transnational families are formed. Transnational family studies on children who are "left behind" indicate that children suffer psychologically from parental migration. Many of the factors identified as affecting children's responses to parental migration however are not considered in child psychology and family sociology studies. This study aims to bridge these areas of knowledge by quantitatively investigating the association between transnational families and children's psychological well-being. It analyzes a survey conducted in three African countries in 2010-11 (Ghana N = 2760; Angola N = 2243; Nigeria N = 2168) amongst pupils of secondary schools. The study compares children in transnational families to those living with their parents in their country of origin. Children's psychological well-being is measured through the Strengths and Difficulties Questionnaire. Multiple regression analyses reveal that children in transnational families fare worse than their counterparts living with both parents but not in Ghana where living conditions mediate this relationship. This paper also looks at four characteristics of transnational families and finds that specific characteristics of transnational families and country contexts matter: (1) changing caregivers is associated with poorer well-being in all countries; (2) which parent migrates does not make a difference in Ghana, when mothers migrate and fathers are caregivers results in poorer well-being in Nigeria, and both mother's and father's migration result in worse outcomes in Angola; (3) the kin relationship of the caregiver is not associated with poorer well-being in Ghana and Nigeria but is in Angola; (4) children with parents who migrate internationally do not show different results than children whose parents migrate nationally in Ghana and Nigeria but in Angola international parental migration is associated with poorer psychological well-being. The study shows that broader characteristics in the population rather than parental migration per se are associated with decreased levels of well-being. PMID:25464874

  2. Biodegradation of Petroleum Hydrocarbons in Soil

    OpenAIRE

    MR Mehrasbi; Haghighi, B.; Shariat, M.; Naseri, S.; Naddafi, K.

    2003-01-01

    Biodegradation of petroleum hydrocarbons (20 g/kg dw soil) was investigated in 3 media, differing in the kind of petroleum fractions. In the laboratory experiments, during 5 months, the activities of petroleum hydrocarbon-degrading microorganisms and dehydrogenase activity of soil was determined. Gas chromatographic analysis showed the biological decontaminations for gas oil, kerosene and synthetic mixture (gas oil, kerosene and furnace oil) are 60 %, 36 % and 55 %, respectively. Dehydrogenas...

  3. Biodegradation of petroleum hydrocarbons in hypersaline environments

    OpenAIRE

    Luiz Fernando Martins; Raquel Silva Peixoto

    2012-01-01

    Literature on hydrocarbon degradation in extreme hypersaline media presents studies that point to a negative effect of salinity increase on hydrocarbonoclastic activity, while several others report an opposite tendency. Based on information available in the literature, we present a discussion on the reasons that justify these contrary results. Despite the fact that microbial ability to metabolize hydrocarbons is found in extreme hypersaline media, indeed some factors are critical for the occu...

  4. Serum laminin, hydrocarbon exposure, and glomerular damage

    OpenAIRE

    Hotz, Philipp; Thielemans, N; Bernard, A; Gutzwiller, Felix; Lauwerys, R

    1993-01-01

    It has been postulated that occupational exposure to hydrocarbons may damage the kidney and lead to glomerulonephritis and chronic renal failure. As laminin is a ubiquitous basement membrane component that seems to play a central part in the structure and function of basement membranes and as the normal renal filtration process is highly dependent on an intact glomerular basement membrane, the serum laminin concentration was examined in a population of workers exposed to hydrocarbons. The hyd...

  5. Macroporous polymer foams by hydrocarbon templating

    OpenAIRE

    Shastri, Venkatram Prasad; Martin, Ivan; Langer, Robert

    2000-01-01

    Porous polymeric media (polymer foams) are utilized in a wide range of applications, such as thermal and mechanical insulators, solid supports for catalysis, and medical devices. A process for the production of polymer foams has been developed. This process, which is applicable to a wide range of polymers, uses a hydrocarbon particulate phase as a template for the precipitation of the polymer phase and subsequent pore formation. The use of a hydrocarbon template allows for enhanced control ov...

  6. Formation of hydrocarbons by bacteria and algae

    Energy Technology Data Exchange (ETDEWEB)

    Tornabene, T.G.

    1980-12-01

    A literature review has been performed summarizing studies on hydrocarbon synthesis by microorganisms. Certain algal and bacterial species produce hydrocarbons in large quantities, 70 to 80% of dry cell mass, when in a controlled environment. The nutritional requirements of these organisms are simple: CO/sub 2/ and mineral salts. The studies were initiated to determine whether or not microorganisms played a role in petroleum formation. 90 references. (DMC)

  7. FLUID MIGRATION HISTORY FROM ANALYSIS OF FILLING FRACTURES IN A CARBONATE FORMATION: (LOWER CRETACEOUS, MIDDLE MAGDALENA VALLEY BASIN, COLOMBIA)

    OpenAIRE

    Jairo Conde-Gómez; Luis-Carlos Mantilla-Figueroa; Juliá;n-Francisco Naranjo-Vesga; Nelson Sá;nchez-Rueda

    2011-01-01

    ABSTRACT The integration of Conventional Petrography, SEM, Rare Earth Element geochemistry (REE) and Fluid Inclusions analysis (FI), in the fracture fillings at the Rosablanca Formation (Middle Magdalena Valley basin), make it possible to relate opening and filling events in the veins with hydrocarbon migration processes. Petrographic and SEM data indicate that the veins are fracture filling structures, with three types of textures:1) Granular aggregates of calcite (GA); 2) Elongated granular...

  8. On the radiolysis of ethylene ices by energetic electrons and implications to the extraterrestrial hydrocarbon chemistry

    International Nuclear Information System (INIS)

    The chemical processing of ethylene ices (C2H4) by energetic electrons was investigated at 11 K to simulate the energy transfer processes and synthesis of new molecules induced by secondary electrons generated in the track of galactic cosmic ray particles. A combination of Fourier transform infrared spectrometry (solid state) and quadrupole mass spectrometry (gas phase) resulted in the identification of six hydrocarbon molecules: methane (CH4), the C2 species acetylene (C2H2), ethane (C2H6), the ethyl radical (C2H5), and—for the very first time in ethylene irradiation experiments—the C4 hydrocarbons 1-butene (C4H8) and n-butane (C4H10). By tracing the temporal evolution of the newly formed molecules spectroscopically online and in situ, we were also able to fit the kinetic profiles with a system of coupled differential equations, eventually providing mechanistic information, reaction pathways, and rate constants on the radiolysis of ethylene ices and the inherent formation of smaller (C1) and more complex (C2, C4) hydrocarbons involving carbon-hydrogen bond ruptures, atomic hydrogen addition processes, and radical-radical recombination pathways. We also discuss the implications of these results on the hydrocarbon chemistry on Titan's surface and on ice-coated, methane-bearing interstellar grains as present in cold molecular clouds such as TMC-1.

  9. Secondary metabolites from Ganoderma.

    Science.gov (United States)

    Baby, Sabulal; Johnson, Anil John; Govindan, Balaji

    2015-06-01

    Ganoderma is a genus of medicinal mushrooms. This review deals with secondary metabolites isolated from Ganoderma and their biological significance. Phytochemical studies over the last 40years led to the isolation of 431 secondary metabolites from various Ganoderma species. The major secondary compounds isolated are (a) C30 lanostanes (ganoderic acids), (b) C30 lanostanes (aldehydes, alcohols, esters, glycosides, lactones, ketones), (c) C27 lanostanes (lucidenic acids), (d) C27 lanostanes (alcohols, lactones, esters), (e) C24, C25 lanostanes (f) C30 pentacyclic triterpenes, (g) meroterpenoids, (h) farnesyl hydroquinones (meroterpenoids), (i) C15 sesquiterpenoids, (j) steroids, (k) alkaloids, (l) prenyl hydroquinone (m) benzofurans, (n) benzopyran-4-one derivatives and (o) benzenoid derivatives. Ganoderma lucidum is the species extensively studied for its secondary metabolites and biological activities. Ganoderma applanatum, Ganoderma colossum, Ganoderma sinense, Ganoderma cochlear, Ganoderma tsugae, Ganoderma amboinense, Ganoderma orbiforme, Ganoderma resinaceum, Ganoderma hainanense, Ganoderma concinna, Ganoderma pfeifferi, Ganoderma neo-japonicum, Ganoderma tropicum, Ganoderma australe, Ganoderma carnosum, Ganoderma fornicatum, Ganoderma lipsiense (synonym G. applanatum), Ganoderma mastoporum, Ganoderma theaecolum, Ganoderma boninense, Ganoderma capense and Ganoderma annulare are the other Ganoderma species subjected to phytochemical studies. Further phytochemical studies on Ganoderma could lead to the discovery of hitherto unknown biologically active secondary metabolites. PMID:25975187

  10. Birds and polycyclic aromatic hydrocarbons

    Science.gov (United States)

    Albers, P.H.

    2006-01-01

    Polycyclic aromatic hydrocarbons (PAH) are present throughout the global environment and are produced naturally and by activities of humans. Effects of PAH on birds have been determined by studies employing egg injection, egg immersion, egg shell application, single and multiple oral doses, subcutaneous injection, and chemical analysis of field-collected eggs and tissue. The four-to six-ring aromatic compounds are the most toxic to embryos, young birds, and adult birds. For embryos, effects include death, developmental abnormalities, and a variety of cellular and biochemical responses. For adult and young birds, effects include reduced egg production and hatching, increased clutch or brood abandonment, reduced growth, increased organweights, and a variety of biochemical responses. Trophic level accumulation is unlikely. Environmental exposure to PAH in areas of high human population or habitats affected by recent petroleum spills might be sufficient to adversely affect reproduction. Evidence of long-term effects of elevated concentrations of environmental PAH on bird populations is very limited and the mechanisms of effect are unclear.

  11. Petroleum Migration, Filling and Biological Degradation in Mesozoic Reservoirs in the Northern North Sea

    Energy Technology Data Exchange (ETDEWEB)

    Horstad, I.

    1995-12-31

    This thesis comprises five papers the first of which discusses the distribution of petroleum within the Gullfaks Field and applies conventional geochemical techniques to characterize the petroleum distribution within a single field. The paper also shows how understanding geochemical heterogeneities in the petroleum fluids helped to build a better geological model of the development of the Gullfaks Field. Based on this work an improved filling model was proposed for the Gullfaks Field. The second paper discusses the biological degradation of the hydrocarbons within the Gullfaks Field, and shows how several samples from neighbouring fields were analyzed to confirm the filling model of the field. It also demonstrates how the quantification of biological degradation of hydrocarbons in the reservoir places constraints on acceptable models of the geological development of the Tampen Spur Area. The third paper discusses the source vs. sink problems of petroleum migration in the North Sea. The fourth paper is a regional study of the petroleum migration within the Tampen Spur area and proposes a regional migration model. The fifth paper is a detailed reservoir geochemical study of the giant Troll Field on the Horda Platform and proposes a revised filling model for the field. 224 refs., 86 figs., 5 tabs.

  12. Geochemical Variations in Hydrocarbon Components Distribution in a Prograding Deltaic Sequence: A Case Study of the Baram Delta, Offshore Sarawak Basin, Malaysia

    Directory of Open Access Journals (Sweden)

    J. Ben-Awuah

    2014-03-01

    Full Text Available Studies on hydrocarbon distribution have evolved from basic reservoir characterization to complex studies today involving the interactions between oil components and clay minerals and sequential extraction studies on hydrocarbon extracts in reservoir rocks. Findings from such studies include the discovery of variations in oil fractions in reservoirs such as adsorbed oil and free oil. The theory that first oil charge preferentially interacts with clay minerals occurring in pores and as coatings in reservoirs was also proposed by some researchers. Despite, all these studies some aspects of variations in the composition of hydrocarbons in reservoir rocks still need to be investigated further. This study has been carried out particularly because the qualitative and quantitative composition of aromatic and aliphatic components of hydrocarbons in terms of the presence and quantities of hydrocarbon functional groups and how they relate to hydrocarbon migration have not been exhaustively discussed. This study uses Ultra-Violet visible light (UV-vis and Fourier Transform Infra Red (FTIR to characterize variations in hydrocarbon distribution in reservoir quality sandstones from three fields namely BD01, BD02 and BD03 in the Baram Delta, offshore Sarawak and to deduce how these variations relate to differential migration patterns in hydrocarbons. Hydrocarbon extraction was done in the ultra vilolet visible (UV-vis experiment using 0.1M sodium pyrophosphate as solvent whereas in the Fourier Transform Infra Red (FTIR, the experiment was done on very fine powdered samples of the sandstones. Results from both the UV-vis and FTIR experiments indicate a dominance of aromatic functional groups in the samples. Most of the samples have E4/E6 ratio of more than 1 which indicates a high degree of aromacity. The BD01 field sandstones with a maximum porosity of 32% has the highest average E4/E6 ratio of 1.21, followed by the BD02 field sandstones with a maximum porosity of 29% and average E4/E6 ratio of 1.19 and the BD03 field with a maximum porosity of 20% and an average E4/E6 ratio of 1.09. The dominance of aromatics in the samples is interpreted as a possible indication of episodes of migration of aliphatics in the past leaving the aromatics behind with the variations in E4/E6 ratio reflecting the micro heterogeneities in the samples.

  13. The International-Migration Network

    CERN Document Server

    Fagiolo, Giorgio

    2012-01-01

    This paper studies international migration from a complex-network perspective. We define the international-migration network (IMN) as the weighted-directed graph where nodes are world countries and links account for the stock of migrants originated in a given country and living in another country at a given point in time. We characterize the binary and weighted architecture of the network and its evolution over time in the period 1960-2000. We find that the IMN is organized around a modular structure characterized by a small-world pattern displaying disassortativity and high clustering, with power-law distributed weighted-network statistics. We also show that a parsimonious gravity model of migration can account for most of observed IMN topological structure. Overall, our results suggest that socio-economic, geographical and political factors are more important than local-network properties in shaping the structure of the IMN.

  14. Migrating lumbar facet joint cysts

    International Nuclear Information System (INIS)

    The majority of lumbar facet joint cysts (LFJCs) are located in the spinal canal, on the medial aspect of the facet joint with characteristic diagnostic features. When they migrate away from the joint of origin, they cause diagnostic problems. In a 7-year period we examined by computed tomography (CT) and magnetic resonance (MR) imaging five unusual cases of facet joint cysts which migrated from the facet joint of origin. Three LFJCs were identified in the right S1 foramen, one in the right L5-S1 neural foramen and one in the left erector spinae and multifidus muscles between the levels of L2-L4 spinous process. Awareness that spinal lesions identified at MRI and CT could be due to migrating facet joint cyst requires a high level of suspicion. The identification of the appositional contact of the cyst and the facet joint needs to be actively sought in the presence of degenerative facet joints. (orig.)

  15. Laser spectroscopy of hydrocarbon radicals

    Energy Technology Data Exchange (ETDEWEB)

    Chen, P. [Harvard Univ., Cambridge, MA (United States)

    1993-12-01

    The author reports the application of supersonic jet flash pyrolysis to the specific preparation of a range of organic radicals, biradicals, and carbenes in a skimmed molecular beam. Each species was produced cleanly and specifically, with little or no secondary reactions by the thermal dissociation of appropriately designed and synthesized organic precursors. Photoelectron spectra of the three isomeric C{sub 3}H{sub 2} carbenes, ortho-benzyne, and the {alpha},3-dehydrotoluene biradical, were used to establish adiabatic ionization potentials for use in thermochemical determinations.

  16. Does migration arbitrage regional labor market differentials?

    Science.gov (United States)

    Gabriel, S A; Shack-marquez, J; Wascher, W L

    1993-04-01

    "This paper examines the determinants of regional migration [in the United States] in the 1980s using a place-to-place migration model in which migration flows depend upon the relative economic opportunities in the origin and destination regions. Using the results of the model, we then examine the potential role for migration in diffusing the economic pressures associated with disparate regional economic growth. Although the results reinforce the notion that divergent regional growth was an impetus to migration in the 1980s, estimates of the employment status of movers suggest that the true effects of migration on unemployment differentials may be quite small." PMID:12345129

  17. Asian migration and international relations: future perspectives

    Directory of Open Access Journals (Sweden)

    Graziano Battistella

    2005-01-01

    Full Text Available Migration has been largely neglected in the study of international relations. However, complex changes involving the formation of transnational communities and the relativization of borders, and the challenges posed by ensuring security, furthering development, and establishing good governance require a fresh look into the issue. Thispaper only indicates some directions, considering the Asian region as the context. First, migration is considered an issue affecting international relations because of security concerns. Second, the impact of migration on international relations is approached fromthe role of migration in economic relations. Finally, the link between governance and migration as well as international aspects in the management of migration are examined.

  18. Depth migration and de-migration for 3-D migration velocity analysis; Migration profondeur et demigration pour l'analyse de vitesse de migration 3D

    Energy Technology Data Exchange (ETDEWEB)

    Assouline, F.

    2001-07-01

    3-D seismic imaging of complex geologic structures requires the use of pre-stack imaging techniques, the post-stack ones being unsuitable in that case. Indeed, pre-stack depth migration is a technique which allows to image accurately complex structures provided that we have at our disposal a subsurface velocity model accurate enough. The determination of this velocity model is thus a key element for seismic imaging, and to this end, migration velocity analysis methods have met considerable interest. The SMART method is a specific migration velocity analysis method: the singularity of this method is that it does not rely on any restrictive assumptions on the complexity of the velocity model to determine. The SMART method uses a detour through the pre-stack depth migrated domain for extracting multi-offset kinematic information hardly accessible in the time domain. Once achieved the interpretation of the pre-stack depth migrated seismic data, a kinematic de-migration technique of the interpreted events enables to obtain a consistent kinematic database (i.e. reflection travel-times). Then, the inversion of these travel-times, by means of reflection tomography, allows the determination of an accurate velocity model. To be able to really image geologic structures for which the 3-D feature is predominant, we have studied the implementation of migration velocity analysis in 3-D in the context of the SMART method, and more generally, we have developed techniques allowing to overcome the intrinsic difficulties in the 3-D aspects of seismic imaging. Indeed, although formally the SMART method can be directly applied to the case of 3-D complex structures, the feasibility of its implementation requires to choose well the imaging domain. Once this choice done, it is also necessary to conceive a method allowing, via the associated de-migration, to obtain the reflection travel-times. We first consider the offset domain which constitutes, still today, the strategy most usually used for the application of migration velocity analysis. We are interested in particular in an important problem: the influence of irregularities in seismic acquisition on the quality of the depth migrated images. Indeed, 3-D seismic acquisitions show irregularities which are characterized by offset variations as well as a non uniform spatial sampling of the data. To overcome the first kind of irregularities, we propose to introduce the concept of migration by offset class in which are migrated all seismic traces that belong to a given offset class, and we show that such a migration relies on a sound theoretical basis whenever the offset varies smoothly with the midpoint coordinate. These theoretical considerations are validated experimentally: offset classes constructed so that the offset varies slowly with the midpoint coordinate allow to obtain the required imaging quality for migration velocity analysis. The influence, on the quality of the migrated images, of a non uniform spatial sampling of the data is, as for it, much more important than the one linked to offset variations: the computation of the superposition of migrated images associated with each midpoint requires the use of a genuine numerical integration formula. We study quadrature formulas based on polynomial interpolation procedures of the function to be integrated. We recommend to use the Hermite interpolation based numerical integration formula if we are primarily interested in amplitude variations in the case of gently dipping layers, and the Lagrange interpolation based numerical integration formula for the imaging of structures involving some complexity. Moreover, the implementation of these schemes of interpolation consists of a preprocessing of the data and does not really increase the CPU time required for running the migration itself. Of course, these approaches require that the distribution of midpoints is dense enough so as to take correctly into account the variations of the function to be integrated. However, the imaging in the offset domain turns out to be with difficulty viable, becau

  19. Rural migration in southern Nevada

    International Nuclear Information System (INIS)

    This study reviews the history of migration in two rural counties in Southern Nevada. It is part of a larger study about the impact of a proposed high-level nuclear waste repository on, in and out-migration patterns in the state. The historical record suggests a boom and bust economic cycle has predominated in the region for the past century creating conditions that should be taken into account, by decision makers, when ascertaining the long-term impacts of the proposed repository

  20. International Migration, Remittances and Development

    Directory of Open Access Journals (Sweden)

    Hasan Mahmud

    2009-02-01

    Full Text Available The increasing remittance flows to the labor sending developing countries in recent years have generated huge optimism in the contemporary development discourse about the possibility of development at the grassroots levels which has been an overwhelming challenge for the development actors for decades. However, the realization of such potential proves difficult due to a lack of common understanding of the phenomenon of labor migration and its causes and consequences. This study focuses on the existing literature on international labor migration, its causes and consequences with a view to identify a common line of theorizing about the issue in question. 

  1. The application of geomembranes for controlling diffusive migration of hydrocarbons in cold region environments

    Energy Technology Data Exchange (ETDEWEB)

    McWatters, R. [Queen' s Univ., Kingston, ON (Canada). Dept. of Civil Engineering; Rutter, A. [Queen' s Univ., Kingston, ON (Canada). School of Environmental Studies; Rowe, R.K. [Queen' s Univ., Kingston, ON (Canada). Dept. of Civil Engineering, Geoengineering Centre

    2010-07-01

    Geomembranes are often used in the design of landfills, barriers, or biopiles in cold regions. This study was conducted to assess the performance of a geomembrane in cold weather. The partitioning, diffusion, and permeation coefficients 5 geomembranes were investigated in a series of diffusion and sorption tests. Benzene, toluene, ethylbenzenes, and xylenes were used as source contaminants over a temperature range of 2 to 24 degrees C on a 0.53 mm linear low density polyethylene (LLDPE) geomembrane; a 1.5 mm high density polyethylene HDPE geomembrane; and a 0.53 mm co-extruded LLDPE geomembrane with an ethylene vinyl alcohol EVOH inner core. The effect of exposure to cold climates and freeze-thaw cycles on the ability of the membranes to act as diffusive barriers to contaminants was investigated. Results of the study showed that the EVOH co-extruded geomembrane had the lowest permeation coefficients. An HDPE samples recovered from a test plot at an Arctic landfill showed that the aged geomembrane had similar partitioning, diffusion and permeation values as the unexposed geomembrane.

  2. Hydrocarbon potential of the Lower Amaranth M Pool, Waskada Field, southwest Manitoba

    Energy Technology Data Exchange (ETDEWEB)

    Karasinski, D.R.; Last, W.M. [Manitoba Univ., Winnipeg, MB (Canada). Dept. of Geological Science; Martiniuk, C.D. [Manitoba Industry, Economic Development and Mines, Winnipeg, MB (Canada). Petroleum Branch

    2005-07-01

    The major hydrocarbon producer of Manitoba's Waskada Field is the Lower Amaranth Member of the Jurassic Amaranth, the oldest Mesozoic unit in the northeastern portion of the Williston Basin. Reservoir facies occur as sandy intervals on logs, and are complexly interbedded intertidal sandstones and siltstones. Thickness of the Lower Member is controlled by the paleotopography of the underlying Paleozoic erosional surface. Hydrocarbon production in the Waskada Amaranth began in 1980 with the recompletion of a former Mississippian producer. In the mid-1990s, the Waskada Field expanded eastward into the Goodlands area, with the development of the Lower Amaranth M pool. Developed original oil in place (OOIP) is calculated to be 9.8 million bbl, with 6.7 per cent primary recovery. However, net pay data from the M pool shows that the current pool boundaries do not accurately represent the absolute pool limits. Extent of the pool is defined by a diagenetically controlled permeability pinchout, where reduced permeability allows water migration, while simultaneously retarding oil migration. Total potential of the M pool has yet to be reached. Two development targets have been identified adjacent to the current M pool boundaries based on reservoir facies thickness, net pay, and production data. Development of these areas would expand the pool boundaries by 632 ha, increasing M pool total OOIP to 28.5 million bbl, leaving an undeveloped 18.7 million bbl.

  3. High-resolution gas chromatographic analysis of polycyclic aromatic hydrocarbons and aliphatic hydrocarbons

    International Nuclear Information System (INIS)

    A study of the analysis by gas chromatography of aromatic polycyclic hydrocarbons and aliphatic hydrocarbons is presented. The separation has been carried out by glass and fused silica capillary column in two different polar stationary phases OV-1 and SE-54. The limitation and the advantages of the procedure are discussed in terms of separation, sensitivity and precision. (Author) 20 refs

  4. Dynamic growth of carbon nanopillars and microrings in electron beam induced dissociation of residual hydrocarbons

    International Nuclear Information System (INIS)

    Electron beam induced dissociation (EBID) of residual hydrocarbons is a common contamination problem in electron microscopy. Formation of amorphous carbon thin films, dots, rings, and complex three-dimensional (3D) structures has been documented. In recent years there has been a renewed interest in utilization EBID of residual hydrocarbons for nanomanufacturing and metrology. With the increase and the diversification of EBID applications, ability for an a priori prediction of the appropriate deposition settings (such as electron beam current, diameter, and energy) that would result in a desired deposit size and geometry is becoming increasingly important. Toward this end, we report how simulations can be used to quantitatively predict the complex shape and non-linear dynamics of secondary ring-type microstructures formed around nanopillar deposits. The deposition experiments were performed on a Si(1 0 0) substrate for different electron beam energies and currents. Deposit shape and transient evolution were characterized using atomic force microscopy and critically compared against simulations results

  5. Hydrocarbon level detection with nanosecond laser ablation

    International Nuclear Information System (INIS)

    Nanosecond laser induced breakdown in liquid is used as a technique to detect hydrocarbon levels in water. A Q-switched Nd:YAG laser was focused to generate optical breakdown associated with shock wave generation. The shock wave was propagated at the speed of sound in the medium after travelling 1 ?s outward from the center of optical breakdown. Different amplitudes of sound were traced with the aid of an ultrasonic probe. The optical properties of the hydrocarbon solution were quantified via fundamental refractive index measurement (the Snell law). A continuous mode diode pumped solid state laser with second harmonic generation was used as the illumination light source. A CCD video camera with Matrox version 4.2 software was utilized to analyze the recording image. Option line analysis was performed to analyze the intensity of optical breakdown at different input energies. Gray level analysis was also conducted on the scattering light after passing through the hydrocarbon solution at different concentrations. The hydrocarbon solution comprised impurities or particles that varied according to the concentration. The average of the gray level is assumed to present the size of the particle. Inherently, as the acoustic wave propagates outward, it transports the mass (particles or impurities) and impacts on the ultrasonic probe. As a result a higher concentration of hydrocarbons reveals a larger amplitude of sound waves. This phenomenon is identified as a finger hydrocarbon levels between 100 and 1000 ppm. The transient detection, without complicated sampling preparation and no hazardous chemical involvement, makes laser ablation a promising technique to detect in situ hydrocarbon levels in water. (paper)

  6. Volatile hydrocarbons inhibit methanogenic crude oil degradation

    Directory of Open Access Journals (Sweden)

    AngelaSherry

    2014-04-01

    Full Text Available Methanogenic degradation of crude oil in subsurface sediments occurs slowly, but without the need for exogenous electron acceptors, is sustained for long periods and has enormous economic and environmental consequences. Here we show that volatile hydrocarbons are inhibitory to methanogenic oil biodegradation by comparing degradation of an artificially weathered crude oil with volatile hydrocarbons removed, with the same oil that was not weathered. Volatile hydrocarbons (nC5-nC10, methylcyclohexane, benzene, toluene and xylenes were quantified in the headspace of microcosms. Aliphatic (n-alkanes nC12-nC34 and aromatic hydrocarbons (4-methylbiphenyl, 3-methylbiphenyl, 2-methylnaphthalene, 1-methylnaphthalene were quantified in the total hydrocarbon fraction extracted from the microcosms. 16S rRNA genes from key microorganisms known to play an important role in methanogenic alkane degradation (Smithella and Methanomicrobiales were quantified by quantitative PCR. Methane production from degradation of weathered oil in microcosms was rapid (1.1 ± 0.1 µmol CH4/g sediment/day with stoichiometric yields consistent with degradation of heavier n-alkanes (nC12-nC34. For non-weathered oil, degradation rates in microcosms were significantly lower (0.4 ± 0.3 µmol CH4/g sediment/day. This indicated that volatile hydrocarbons present in the non-weathered oil inhibit, but do not completely halt, methanogenic alkane biodegradation. These findings are significant with respect to rates of biodegradation of crude oils with abundant volatile hydrocarbons in anoxic, sulphate-depleted subsurface environments, such as contaminated marine sediments which have been entrained below the sulfate-reduction zone, as well as crude oil biodegradation in petroleum reservoirs and contaminated aquifers.

  7. Volatile hydrocarbons inhibit methanogenic crude oil degradation.

    Science.gov (United States)

    Sherry, Angela; Grant, Russell J; Aitken, Carolyn M; Jones, D Martin; Head, Ian M; Gray, Neil D

    2014-01-01

    Methanogenic degradation of crude oil in subsurface sediments occurs slowly, but without the need for exogenous electron acceptors, is sustained for long periods and has enormous economic and environmental consequences. Here we show that volatile hydrocarbons are inhibitory to methanogenic oil biodegradation by comparing degradation of an artificially weathered crude oil with volatile hydrocarbons removed, with the same oil that was not weathered. Volatile hydrocarbons (nC5-nC10, methylcyclohexane, benzene, toluene, and xylenes) were quantified in the headspace of microcosms. Aliphatic (n-alkanes nC12-nC34) and aromatic hydrocarbons (4-methylbiphenyl, 3-methylbiphenyl, 2-methylnaphthalene, 1-methylnaphthalene) were quantified in the total hydrocarbon fraction extracted from the microcosms. 16S rRNA genes from key microorganisms known to play an important role in methanogenic alkane degradation (Smithella and Methanomicrobiales) were quantified by quantitative PCR. Methane production from degradation of weathered oil in microcosms was rapid (1.1 ± 0.1 ?mol CH4/g sediment/day) with stoichiometric yields consistent with degradation of heavier n-alkanes (nC12-nC34). For non-weathered oil, degradation rates in microcosms were significantly lower (0.4 ± 0.3 ?mol CH4/g sediment/day). This indicated that volatile hydrocarbons present in the non-weathered oil inhibit, but do not completely halt, methanogenic alkane biodegradation. These findings are significant with respect to rates of biodegradation of crude oils with abundant volatile hydrocarbons in anoxic, sulphate-depleted subsurface environments, such as contaminated marine sediments which have been entrained below the sulfate-reduction zone, as well as crude oil biodegradation in petroleum reservoirs and contaminated aquifers. PMID:24765087

  8. [Migration and health--from deficiency analysis to diversity vision?].

    Science.gov (United States)

    Weber, A; Hörmann, G

    2011-05-01

    In times of globalization the subjects migration and health are gaining more and more in importance. At the same time, one can observe a discrepancy between published opinions, politically intended messages and scientifically proved evidence. With approximately 15.4 million people with a migration background (this is equivalent to approximately 19% of the German population), migrants perform as an important "customer group" for health care and social security. In 2005, the category migrant background was introduced for the first time by the Federal Statistical Office. This category suggests homogeneity, which in fact is not given. Persons with migration background (including active immigrants, their children and grandchildren, repatriates, foreigners), have to be examined in a differentiated way concerning the consequences that the migration process has on health. Apart from potentially pathogenic influences associated with migration (e. g., ethnicity, national origin, cultural/religious characteristics, migration-related stressors), for example, education, social status, life-style and participation in work and society have to be taken into consideration as important "confounders". In this, a recent sociological approach (sinus migrant milieu) could be useful for socio-medical research and practice. Health-relevant information on migrants results on the one hand from scientific studies primarily designed for this purpose and, on the other hand, from routine data from official health reports. In the interpretation of secondary data, the problem arises that the definition of the target group (migrants) is different in the diverse data sources (for example, Germans, non-Germans, foreigners, migration background) and that important confounders (for example, from socio-cultural milieu) are not included. This may result in, among other things, an under- or overestimation of health risks or even incorrect conclusions. In consideration of these limitations, by means of data sets from official statistics (among others, Federal Statistical Office, social insurance agencies) and recent scientific research the present article analyses chosen aspects of migrant health (for example, health behaviour, morbidity, sickness absence, early retirement, health-care system, rehabilitation and mortality). Finally, possible implications for a more intensive discussion and further development of health care practice are pointed out. PMID:20383824

  9. Petroleum hydrocarbons and polycyclic aromatic hydrocarbons (PAHs) in Hong Kong marine sediments

    International Nuclear Information System (INIS)

    A total of 20 surficial sediment samples, obtained from Hong Kong coastal waters, were analysed for petroleum hydrocarbons (PHCs) and a suite of 15 polycyclic aromatic hydrocarbons (PAHs). The results indicate that Hong Kong coastal sediments are often seriously polluted with petroleum related hydrocarbons. This is especially so in heavily urbanised or industrialized localities, such as Kowloon Bay (Victoria Harbour), Tsing Yi North and Tolo Harbour. Petroleum hydrocarbon pollutants in marine sediments are believed to be mainly derived from the transportation of oil, shipping activities, spillages, and industrial, stormwater and waste wastewater discharge. The ratio of unresolved complex mixture (UCM) to n-alkanes, carbon preference index (CPI), and n-C16 values indicate that the main contribution to petroleum hydrocarbon contamination is via oil and its products. Pollutant sources appear to be stable and continuing when compared with previous data. (author)

  10. Oil characterisation: assessment of composition, risks, degradation and remediation potential of total petroleum hydrocarbons in soil

    International Nuclear Information System (INIS)

    Several methods are available for the characterization of petroleum hydrocarbons. The TPHCWG (Total Petroleum Hydrocarbon Criteria Working Group) developed a method based on a silica column separation of aromatics and aliphatics and a GC-FID subdivision into equivalent-carbon fractions (EC) ('TPH-method'). This method was mainly developed for assessing human risks of oil compounds. Within NOBIS (Dutch Research program Biological In-situ Remediation), another method was developed based upon an equilibrium-experiment of the oil-polluted soil with water (column recirculation), which was further developed by TTE ('TTE-method'). This method uses measured water solubilities of individual oil components and GC-retention times yielding a subdivision of the hydrocarbons into compound classes that are relevant for assessing the remediation potential of the specific oil pollution. In this paper we present results of a research project in which we developed a new method, the 'OK-method' that combines these two procedures and allows a complete characterisation of the oil in terms of composition, (human) risks, volatility, solubility, plume behaviour (migration velocities of the soluble components) and aerobic degradation potential. (authors)

  11. Post-harvest sources of polycyclic aromatic hydrocarbon contamination of Cocoa beans: A simulation

    Directory of Open Access Journals (Sweden)

    Lowor et al.

    2012-11-01

    Full Text Available Polycyclic Aromatic Hydrocarbons (PAH’s are a group of fused C6-aromatic compounds present in tar, asphalt, some pesticides and exhaust fumes. They are widespread in the environment (air, water, soil, foods and are very soluble in fats and oils (like cocoa butter. Current cocoa post-harvest practices in some countries supposedly lead to high levels of PAH contamination in cocoa beans. The EU is currently considering a 2 ppb Benzo(apyrene limit on cocoa butter. To improve post-harvest practices in order to reduce PAH contamination, this study was carried out to identify the main sources of PAH contamination of cocoa beans through intentional contamination experiments, involving artificial drying using fire, drying by roadside and storage in diesel contaminated jute sacks. Results indicated that the main cause of PAH in cocoa was through smoke contamination of the beans during drying or storage when the beans came into direct contact with hydrocarbons. This led to heavy contamination, but most of the contamination resided on the shell. Some contamination of the cocoa nibs/cocoa butter however occurred through limited migration of the PAH to the nibs. Broad range recommendations to the cocoa industry are discussed. Briefly, farmer education is needed to warn farmers against the use of fires to dry cocoa beans and storage of cocoa beans together with common hydrocarbon sources such as kerosene, diesel or petrol.

  12. Secondary emission gas chamber

    CERN Document Server

    In'shakov, V; Skvortsov, V

    2014-01-01

    For a hadron calorimeter active element there is considered a gaseous secondary emis-sion detector (150 micron gap, 50 kV/cm). Such one-stage parallel plate chamber must be a radiation hard, fast and simple. A model of such detector has been produced, tested and some characteristics are presented.

  13. Modernising Portugal's Secondary Schools

    Science.gov (United States)

    Heitor, Teresa V.

    2008-01-01

    Portugal has a total of 477 public secondary schools. Some date from the end of the 19th century but the majority were built after 1970, reflecting the period of expansion in the school network and the extension of compulsory schooling. The schools are heterogeneous in terms of building types, architectural features and quality. An assessment of…

  14. 2D numerical modelling of hydrocarbon generation in subducted sediments at the active continental margin of Costa Rica

    Energy Technology Data Exchange (ETDEWEB)

    Lutz, R. [Federal Inst. for Geosciences and Natural Resources (BGR), Hannover (Germany); RWTH Aachen Univ. (Germany). Inst. of Geology and Geochemistry of Petroleum and Coal; Littke, R. [RWTH Aachen Univ. (Germany). Inst. of Geology and Geochemistry of Petroleum and Coal; Gerling, P.; Boennemann, C. [Federal Inst. for Geosciences and Natural Resources (BGR), Hannover (Germany)

    2004-06-01

    The Middle America Trench is the topographic expression of the subduction of the Cocos Plate beneath the Caribbean Plate. In this study, the subduction process was simulated in a numerical basin model to determine the fate of the organic matter. During subduction, temperature rises and the organic matter embedded in sediments generates hydrocarbons. However, equilibrium temperatures are not reached due to the fast subduction process, shifting the petroleum generation zone to depths exceeding 10,000 m. The average organic carbon content of the subducted sediments is low but the fast subduction leads to a high rate of hydrocarbon generation. For example, along a 1 km wide section along the subduction zone a methane generation rate of about 9 x 10{sup 5} m{sup 3}/a is calculated. The hydrocarbon generation process occurs at much greater depth than in conventional sedimentary basins. Due to the low migration velocity, oil is transported from the kitchen area to a greater depth and finally transformed to methane. Interestingly, calculated migration velocities of methane are mostly lower than the current subduction velocity. Thus, even methane is further subducted. This modelling result is confirmed by published data on gas composition at the trench, where (almost) no thermogenic gas has been detected. The subduction of large amounts of methane to very great depths could have an effect on volcanism in the back arc region or on metamorphic processes. (author)

  15. Secondary impact hazard assessment

    Science.gov (United States)

    1986-01-01

    A series of light gas gun shots (4 to 7 km/sec) were performed with 5 mg nylon and aluminum projectiles to determine the size, mass, velocity, and spatial distribution of spall and ejecta from a number of graphite/epoxy targets. Similar determinations were also performed on a few aluminum targets. Target thickness and material were chosen to be representative of proposed Space Station structure. The data from these shots and other information were used to predict the hazard to Space Station elements from secondary particles resulting from impacts of micrometeoroids and orbital debris on the Space Station. This hazard was quantified as an additional flux over and above the primary micrometeoroid and orbital debris flux that must be considered in the design process. In order to simplify the calculations, eject and spall mass were assumed to scale directly with the energy of the projectile. Other scaling systems may be closer to reality. The secondary particles considered are only those particles that may impact other structure immediately after the primary impact. The addition to the orbital debris problem from these primary impacts was not addressed. Data from this study should be fed into the orbital debris model to see if Space Station secondaries make a significant contribution to orbital debris. The hazard to a Space Station element from secondary particles above and beyond the micrometeoroid and orbital debris hazard is categorized in terms of two factors: (1) the 'view factor' of the element to other Space Station structure or the geometry of placement of the element, and (2) the sensitivity to damage, stated in terms of energy. Several example cases were chosen, the Space Station module windows, windows of a Shuttle docked to the Space Station, the habitat module walls, and the photovoltaic solar cell arrays. For the examples chosen the secondary flux contributed no more than 10 percent to the total flux (primary and secondary) above a given calculated critical energy. A key assumption in these calculations is that above a certain critical energy, significant damage will be done. This is not true for all structures. Double-walled, bumpered structures are an example for which damage may be reduced as energy goes up. The critical energy assumption is probably conservative, however, in terms of secondary damage. To understand why the secondary impacts seem to, in general, contribute less than 10 percent of the flux above a given critical energy, consider the case of a meteoroid impact of a given energy on a fixed, large surface. This impact results in a variety of secondary particles, all of which have much less energy than the original impact. Conservation of energy prohibits any other situation. Thus if damage is linked to a critical energy of a particle, the primary flux will always deliver particles of much greater energy. Even if all the secondary particles impacted other Space Station structures, none would have a kinetic energy more than a fraction of the primary impact energy.

  16. [Migration of dentists within Hungary].

    Science.gov (United States)

    Balázs, Péter

    2010-09-01

    Concerning the human resource management in the health care, Hungarian analysts focus mainly on cross-national migration, which was instigated considerably by joining the European Union in 2004. Contrasted to other health care professionals, dentists emphasized also the importance of in-country migration (mobility) indicating serious dangers of developing inequalities in the dental service. From the point of view of health system planning, the main problem is to balance the needs and the number of professionals in regions and areas with extremely different socio-economic conditions. Under dictatorial governments, this "balancing" (which was experienced also in Hungary) is a forced allocation of young professionals to the target regions. In political freedom and free market economy, these measures are unthinkable. The present domestic area distribution, concerning also the supply through vacancies by old age inactivity and cross-national migration, is ruled by personal decisions of actually graduated and immigrant professionals respectively. Therefore, it is unavoidable to investigate the interrelation of factors (dentists' births place, study migration and decisions for practice allocation) ruling the in-country geographic patterns of dental practices. This evidence-based knowledge can only explain the present situation and provide guidelines for health policy decision makers. PMID:21058494

  17. Clocks, cryptochromes and Monarch migrations

    Science.gov (United States)

    Kyriacou, Charalambos P

    2009-01-01

    The annual migration of the Monarch butterfly (Danaus plexippus) from eastern North America to central Mexico is one of nature's most inspiring spectacles. Recent studies including one in BMC Biology, have begun to dissect the molecular and neurogenetic basis for this most complex behavior. PMID:19591650

  18. INTERNATIONAL MIGRATION FLOWS: GENDER DIVERSITY

    Directory of Open Access Journals (Sweden)

    Tamara Vladimirovna Kuprina

    2015-02-01

    Full Text Available At the present stage of the development of the society many researchers state the increasing role of gender in international migration flows and problems associated with it. However, this perspective is not sufficiently studied, respectively it is very difficult to give specific advice to ensure the socio-cultural security of female migration which is considered a high-risk area. The paper presents an analysis of the still few data obtained in Europe and Russian cities. The empirical base of the study was obtained through questionnaires and interviews, mainly of migrant women. The analysis revealed the acceptability of migration for women of different ethnic groups, their motivation for going abroad, their desire for financial independence, the relationship of professional and family responsibilities, their social circles in the host country and their plans for the future. Particular attention is paid to migration flows from Middle Asia. At the end of the article there are some recommendations on possible trends providing socio-cultural security of migrants and the host society.

  19. Material migration in divertor tokamaks

    International Nuclear Information System (INIS)

    Erosion of plasma facing material, its transport through the plasma and its deposition define the topic of material migration. It is a subject which is a pivotal issue both for ITER and for the longer term economic and technological viability of fusion power. This review summarises the current status and future direction of this field

  20. Long migration flights of birds

    International Nuclear Information System (INIS)

    The extremely long migration flights of some birds are carried out in one hop, necessitating a substantial prior build-up of fat fuel. We summarize the basic elements of bird flight physics with a simple model, and show how the fat reserves influence flight distance, flight speed and the power expended by the bird during flight. (paper)

  1. A Discrete Cell Migration Model

    Energy Technology Data Exchange (ETDEWEB)

    Nutaro, James J [ORNL; Kruse, Kara L [ORNL; Ward, Richard C [ORNL; O' Quinn, Elizabeth [Wofford College; Woerner, Matthew M [ORNL; Beckerman, Barbara G [ORNL

    2007-01-01

    Migration of vascular smooth muscle cells is a fundamental process in the development of intimal hyperplasia, a precursor to development of cardiovascular disease and a potential response to injury of an arterial wall. Boyden chamber experiments are used to quantify the motion of cell populations in response to a chemoattractant gradient (i.e., cell chemotaxis). We are developing a mathematical model of cell migration within the Boyden chamber, while simultaneously conducting experiments to obtain parameter values for the migration process. In the future, the model and parameters will be used as building blocks for a detailed model of the process that causes intimal hyperplasia. The cell migration model presented in this paper is based on the notion of a cell as a moving sensor that responds to an evolving chemoattractant gradient. We compare the results of our three-dimensional hybrid model with results from a one-dimensional continuum model. Some preliminary experimental data that is being used to refine the model is also presented.

  2. Lymphocyte migration studies in man

    International Nuclear Information System (INIS)

    In this paper the author outlines what is known of the migration and recirculation of the lymphocyte in man and animals. He then attempts to demonstrate how a better grasp of these phenomena may contribute to an understanding of the pathophysiology of human diseases such as chronic lymphocytic leukemia, non-Hodgkin's lymphomas, Hodgkin's, and other diseases

  3. Conversion of Ethanol to Hydrocarbons on Hierarchical HZSM-5 Zeolites

    Energy Technology Data Exchange (ETDEWEB)

    Ramasamy, Karthikeyan K.; Zhang, He; Sun, Junming; Wang, Yong

    2014-12-15

    This study reports synthesis, characterization, and catalytic activity of the nano-size hierarchical HZSM-5 zeolite with high mesoporosity produced via a solvent evaporation procedure. Further, this study compares hierarchical zeolites with conventional HZSM-5 zeolite with similar Si/Al ratios for the ethanol-to-hydrocarbon conversion process. The catalytic performance of the hierarchical and conventional zeolites was evaluated using a fixed-bed reactor at 360 °C, 300 psig, and a weight hourly space velocity of 7.9 h-1. For the low Si/Al ratio zeolite (~40), the catalytic life-time for the hierarchical HZSM-5 was approximately 2 times greater than the conventional HZSM-5 despite its coking amount deposited 1.6 times higher than conventional HZSM-5. For the high Si/Al ratio zeolite (~140), the catalytic life-time for the hierarchical zeolite was approximately 5 times greater than the conventional zeolite and the amount of coking deposited was 2.1 times higher. Correlation was observed between catalyst life time, porosity, and the crystal size of the zeolite. The nano-size hierarchical HZSM-5 zeolites containing mesoporosity demonstrated improved catalyst life-time compared to the conventional catalyst due to faster removal of products, shorter diffusion path length, and the migration of the coke deposits to the external surface from the pore structure.

  4. Syngas Upgrading to Hydrocarbon Fuels Technology Pathway

    Energy Technology Data Exchange (ETDEWEB)

    Talmadge, M.; Biddy, Mary J.; Dutta, Abhijit; Jones, Susanne B.; Meyer, Pimphan A.

    2013-03-31

    In support of the Bioenergy Technologies Office, the National Renewable Energy Laboratory (NREL) and the Pacific Northwest National Laboratory (PNNL) are undertaking studies of biomass conversion technologies to hydrocarbon fuels to identify barriers and target research toward reducing conversion costs. Process designs and preliminary economic estimates for each of these pathway cases were developed using rigorous modeling tools (Aspen Plus and Chemcad). These analyses incorporated the best information available at the time of development, including data from recent pilot and bench-scale demonstrations, collaborative industrial and academic partners, and published literature and patents. This pathway case investigates the upgrading of biomass derived synthesis gas (‘syngas’) to hydrocarbon biofuels. While this specific discussion focuses on the conversion of syngas via a methanol intermediate to hydrocarbon blendstocks, there are a number of alternative conversion routes for production of hydrocarbons through a wide array of intermediates from syngas. Future work will also consider the variations to this pathway to determine the most economically viable and risk adverse conversion route. Technical barriers and key research needs have been identified that should be pursued for the syngas to hydrocarbon pathway to be competitive with petroleum-derived gasoline, diesel and jet range blendstocks.

  5. Worldwide overview of hydrocarbons and perspectives

    International Nuclear Information System (INIS)

    This publication presents and comments data regarding the share of hydrocarbons in the world energy consumption, hydrocarbon trade flows, the new situation created by the emergence of shale hydrocarbons and the consequences for the world economy, and possible risks. The authors first comment the evolution of energy consumption and outline that the objectives of CO2 and greenhouse gas emission will not be reached (these emissions increased in 2012 and in 2013). They indicate the emission situation in the USA and Japan, and notice that the objectives defined by the IEA are quite different from those defined by the EU. They analyse the evolutions by distinguishing different periods: 2005-2008 as a reference period, 2008-2012 as a period of change, and the current period as a period of flow inversion. Then, the authors propose two different scenarios of evolution of economic and energy policies. The evolution of hydrocarbon demand is commented, and the levels of reserves (oil, conventional gas, coal, nuclear fuels) are discussed. The market evolution is also discussed, not only from an economic point of view, but also in relationship with geopolitics. The authors notably outline that the energy price is different from one country to the other, discuss the issue of hydrocarbon refining, the role of CO2 tax

  6. Emissions of hydrocarbons from combustion of biofuels

    International Nuclear Information System (INIS)

    Evaluations and measurements of emissions of hydrocarbons from power plants with a capacity exceeding 1 MW using biofuels (wood fuels and peat) have been studied in order to identify and quantify the emissions of incompletely combusted hydrocarbons. The influence of the type of fuel and the combustion technology applied were also studied, using literature references. The report summarizes monitoring results from a number of plants using biofuels. The reported emissions from the different plants can not be compared as they are relatively few and the test results have been obtained under various conditions using different methods of testing and analysis. The methods used are often poorly documented in the studied reports. Few investigations of emissions of hydrocarbons from plants in the range of 1 to 10 MW have been carried out. The plant and the technology used are important factors determining the amount and type of emissions of hydrocarbons. Larger temporary emissions can occur during start up, operational disturbances or when using fuel of inhomogeneous quality. In order to minimize the emissions the combustion process must be efficiently controlled, and a fuel of a hohogeneous quality must be used. The report also summarizes sampling and analysis methods used for monitoring emissions of hydrocarbons. (29 refs., 17 figs.)

  7. Sequential Migration, and the German Reunification

    OpenAIRE

    Birk, Angela

    2004-01-01

    The paper develops a sequential migration model and derives a worker's optimal policies for migration and employment. With the worker's simulated reservation wage functions for employment and migration, a stationary equilibrium is defined. In that equilibrium, stationary distributions of employed and unemployed stayers and movers over different states are derived. The analysis of Markov equilibria shows that mainly unemployed skilled and unskilled migrants will migrate. I have referred to thi...

  8. MIGRATION IN INDIA: BOON OR CURSE

    Directory of Open Access Journals (Sweden)

    Anil R. Patil

    2015-04-01

    Full Text Available Migration is inevitable part of the development. In Indian situation even though more than 50% of the population is dependent on agriculture for their livelihood it is very essential to find out new avenues of employment generation. The refore , industri a l g rowth or industrialisation is one of the source for urban development. Various causes of migration, implications of migration, problems of migration all these aspects are discussed the in this present paper.

  9. Migration and development: a theoretical perspective

    OpenAIRE

    Haas, Hein; 3

    2008-01-01

    This paper aims to put the debate on migration and development in a broader historical perspective of migration theory in particular and social theory in general. The scholarly debate on migration and development has tended to swing back and forth like a pendulum, from developmentalist optimism in the 1950s and 1960s, to structuralist and neo-Marxist pessimism and scepticism over the 1970s and 1980s, to more nuanced views influenced by the new economics of labour migration, “liv...

  10. Theoretical aspects of studying the migration processes

    Directory of Open Access Journals (Sweden)

    Dilfuza Rasulova

    2010-02-01

    Full Text Available In conditions of continuous growth of population in Uzbekistan the issue of managing the labor migration processes is becoming more important. Effective coordination of migration processes requires comprehensive study of theory and methodology of labour migration, particularly considering cases of transition countries. The paper considers some theoretic concepts that seem important for understanding the mechanism of migration princesses, suggests practical recommendations for the associated decision-making.

  11. Theoretical aspects of studying the migration processes

    OpenAIRE

    Dilfuza Rasulova

    2010-01-01

    In conditions of continuous growth of population in Uzbekistan the issue of managing the labor migration processes is becoming more important. Effective coordination of migration processes requires comprehensive study of theory and methodology of labour migration, particularly considering cases of transition countries. The paper considers some theoretic concepts that seem important for understanding the mechanism of migration princesses, suggests practical recommendations for the associated d...

  12. Surgical clip migration following laparoscopic cholecystectomy as a cause of cholangitis.

    Science.gov (United States)

    Photi, Evangelos S; Partridge, Gemma; Rhodes, Michael; Lewis, Michael P N

    2014-01-01

    Gallstone disease is a common surgical presentation, and laparoscopic cholecystectomy is the favoured method of surgical management. Ligation of the cystic duct is usually performed with surgical clips, which have the potential to migrate into the common bile duct with time. This paper describes a case of cholangitis secondary to clip migration in a 42-year-old male patient 9 years after the initial laparoscopic cholecystectomy. Magnetic resonance cholangiopancreaography imaging revealed a surgical clip lodged in dilated common bile duct. The patient was managed successfully by endoscopic retrograde cholangiopancreatography. PMID:24876460

  13. Migration of radionuclides in the soil-crop-food product system and assessment of agricultural countermeasures

    International Nuclear Information System (INIS)

    Studies on dynamics of redistribution of radionuclides through of profile of the different soils on uncultivated agricultural lands of Belarus during the 1986-1995 period show that vertical migration occurs with low rate. In arable soils the radionuclides are distributed in comparatively uniform way through the whole depth of the 25-30 cm cultivated layer. Investigations on migration of radionuclides with wind erosion on the drained series of wet sandy and peat soils and water erosion on sloping lands show that one should take into consideration the secondary contamination of soils while forecasting a possible accumulation of radionuclides in farm products

  14. Multiple atmospheric noble gas components in hydrocarbon reservoirs: a study of the Northwest Shelf, Delaware Basin, SE New Mexico

    Science.gov (United States)

    Kennedy, B. M.; Torgersen, T.; van Soest, M. C.

    2002-09-01

    The Northwest Shelf of the Delaware Basin, SE New Mexico is the site of several large and productive oil and gas fields. The most productive reservoirs are located in the late Pennsylvanian Morrow and early Permian Abo formations. Production from the latter more important play is predominately from fluvial Abo red beds of the Pecos Slope Field. The oxidizing conditions implied by the reddish color of the formation require an external hydrocarbon source. To test the existing migration model for the region and constrain the location of potential hydrocarbon sources, we measured the elemental and isotopic composition of noble gases produced along with the hydrocarbons. We found the hydrocarbons to be highly enriched in radiogenic 4He, 40*Ar and nucleogenic 21*Ne [F( 4He) = 44,000-250,000; 40Ar/ 36Ar = 400-3145; 21Ne/ 22Ne = 0.044-0.071]. The greatest enrichments occur in the Pecos Slope gas fields. The hydrocarbons also contain three independent nonradiogenic noble gas components each with an atmospheric isotopic composition. One component is most likely air-saturated water (ASW). The second component is enriched in the heavy noble gases [F( 130Xe) > 8.5] and is derived from the hydrocarbon sources. The third component is enriched in Ne [F( 20Ne) > 0.8] that we believe is degassed from sources within the reservoirs. This component is correlated with but decoupled from the dominant source of radiogenic 4He and 40*Ar. Very high concentrations of 4He (up to ˜1% by volume) in the Pecos slope reservoirs require a source external to the reservoirs, such as the underlying Precambrian basement granites and sedimentary equivalents. Structural buckles cutting through the Pecos field may act as high flux vertical pathways for the radiogenic 4He. If the hydrocarbons in the Pecos slope fields have migrated northward from the deeper Delaware Basin, as suggested by compositional trends, then perhaps the buckles also play an important role in the distribution and filling of the Pecos slope reservoirs.

  15. Transpiration cooled throat for hydrocarbon rocket engines

    Science.gov (United States)

    May, Lee R.; Burkhardt, Wendel M.

    1991-01-01

    The objective for the Transpiration Cooled Throat for Hydrocarbon Rocket Engines Program was to characterize the use of hydrocarbon fuels as transpiration coolants for rocket nozzle throats. The hydrocarbon fuels investigated in this program were RP-1 and methane. To adequately characterize the above transpiration coolants, a program was planned which would (1) predict engine system performance and life enhancements due to transpiration cooling of the throat region using analytical models, anchored with available data; (2) a versatile transpiration cooled subscale rocket thrust chamber was designed and fabricated; (3) the subscale thrust chamber was tested over a limited range of conditions, e.g., coolant type, chamber pressure, transpiration cooled length, and coolant flow rate; and (4) detailed data analyses were conducted to determine the relationship between the key performance and life enhancement variables.

  16. Using supercritical fluids to refine hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Yarbro, Stephen Lee

    2014-11-25

    This is a method to reactively refine hydrocarbons, such as heavy oils with API gravities of less than 20.degree. and bitumen-like hydrocarbons with viscosities greater than 1000 cp at standard temperature and pressure using a selected fluid at supercritical conditions. The reaction portion of the method delivers lighter weight, more volatile hydrocarbons to an attached contacting device that operates in mixed subcritical or supercritical modes. This separates the reaction products into portions that are viable for use or sale without further conventional refining and hydro-processing techniques. This method produces valuable products with fewer processing steps, lower costs, increased worker safety due to less processing and handling, allow greater opportunity for new oil field development and subsequent positive economic impact, reduce related carbon dioxide, and wastes typical with conventional refineries.

  17. Bioremediation of Petroleum Hydrocarbon Contaminated Sites

    Energy Technology Data Exchange (ETDEWEB)

    Fallgren, Paul

    2009-03-30

    Bioremediation has been widely applied in the restoration of petroleum hydrocarbon-contaminated. Parameters that may affect the rate and efficiency of biodegradation include temperature, moisture, salinity, nutrient availability, microbial species, and type and concentration of contaminants. Other factors can also affect the success of the bioremediation treatment of contaminants, such as climatic conditions, soil type, soil permeability, contaminant distribution and concentration, and drainage. Western Research Institute in conjunction with TechLink Environmental, Inc. and the U.S. Department of Energy conducted laboratory studies to evaluate major parameters that contribute to the bioremediation of petroleum-contaminated drill cuttings using land farming and to develop a biotreatment cell to expedite biodegradation of hydrocarbons. Physical characteristics such as soil texture, hydraulic conductivity, and water retention were determined for the petroleum hydrocarbon contaminated soil. Soil texture was determined to be loamy sand to sand, and high hydraulic conductivity and low water retention was observed. Temperature appeared to have the greatest influence on biodegradation rates where high temperatures (>50 C) favored biodegradation. High nitrogen content in the form of ammonium enhanced biodegradation as well did the presence of water near field water holding capacity. Urea was not a good source of nitrogen and has detrimental effects for bioremediation for this site soil. Artificial sea water had little effect on biodegradation rates, but biodegradation rates decreased after increasing the concentrations of salts. Biotreatment cell (biocell) tests demonstrated hydrocarbon biodegradation can be enhanced substantially when utilizing a leachate recirculation design where a 72% reduction of hydrocarbon concentration was observed with a 72-h period at a treatment temperature of 50 C. Overall, this study demonstrates the investigation of the effects of environmental parameters on bioremediation is important in designing a bioremediation system to reduce petroleum hydrocarbon concentrations in impacted soils.

  18. Pathogenesis of secondary hyperparathyroidism

    OpenAIRE

    Gallieni, Maurizio Alberto; Brancaccio, Diego; Cozzolino, Mario Gennaro

    2009-01-01

    Chronic renal failure is the primary cause of secondary hyperparathyroidism (SHPT). Patients with mineral metabolism disorders commonly present with low serum calcium levels, hyperphosphatemia, and calcitriol deficiency. In normal renal function subjects, parathyroid cells have a low turnover and rarely undergo mitoses. In uremic conditions, however, parathyroid glands become hyperplasic and leave quiescence. During the last ten years, new molecular mechanisms have been investigated to better...

  19. Behaviour in secondary schools

    OpenAIRE

    Challen, Amy

    2013-01-01

    My poster presents descriptive information about pupils’ (mis)behaviour in secondary schools in England, from data I obtained from four comprehensive schools’ behaviour incident databases. The poster is a response to the often sensationalist claims about teenagers’ behaviour made by the press, but is also motivated by my interest in the social, psychological and behavioural aspects of educational attainment. Misbehaving pupils not only affect their own progress, but also disrupt their p...

  20. Dynamics of secondary forests

    OpenAIRE

    Breugel, M.

    2007-01-01

    The succession of tropical secondary forests on abandoned agricultural fields has been studied since long, most often by comparing stands of different age since abandonment. These so-called chronosequence studies have yielded much insight in general patterns of succession and the constraints and conditions that affect the course of succession (shortly reviewed in chapter 1). Successional dynamics, however, are inferred rather than directly monitored in such studies; i.e. direction and rates o...

  1. Influences of environmental cues, migration history and habitat familiarity on partial migration

    OpenAIRE

    Skov, Christian; Aarestrup, Kim; Baktoft, Henrik; Brodersen, Jakob; Brönmark, Christer; Hansson, Lars-Anders; Eg Nielsen, Einar; Nielsen, Tine; Nilsson, Anders

    2010-01-01

    The factors that drive partial migration in organisms are not fully understood. Roach (Rutilus rutilus), a freshwater fish, engage in partial migration where parts of populations switch between summer habitats in lakes and winter habitats in connected streams. To test if the partial migration trait is phenotypically plastic or has genetic components, we translocated roach from 2 populations with different opportunities for migration to a lake with migration opportunity, containing a local roa...

  2. High Molecular Weight Petrogenic and Pyrogenic Hydrocarbons in Aquatic Environments

    Science.gov (United States)

    Abrajano, T. A., Jr.; Yan, B.; O'Malley, V.

    2003-12-01

    Geochemistry is ultimately the study of sources, movement, and fate of chemicals in the geosphere at various spatial and temporal scales. Environmental organic geochemistry focuses such studies on organic compounds of toxicological and ecological concern (e.g., Schwarzenbach et al., 1993, 1998; Eganhouse, 1997). This field emphasizes not only those compounds with potential toxicological properties, but also the geological systems accessible to the biological receptors of those hazards. Hence, the examples presented in this chapter focus on hydrocarbons with known health and ecological concern in accessible shallow, primarily aquatic, environments.Modern society depends on oil for energy and a variety of other daily needs, with present mineral oil consumption throughout the 1990s exceeding 3×109 t yr-1 (NRC, 2002). In the USA, e.g., ˜40% of energy consumed and 97% of transportation fuels are derived from oil. In the process of extraction, refinement, transport, use, and waste production, a small but environmentally significant fraction of raw oil materials, processed products, and waste are released inadvertently or purposefully into the environment. Because their presence and concentration in the shallow environments are often the result of human activities, these organic materials are generally referred to as "environmental contaminants." Although such reference connotes some form of toxicological or ecological hazard, specific health or ecological effects of many organic "environmental contaminants" remain to be demonstrated. Some are, in fact, likely innocuous at the levels that they are found in many systems, and simply adds to the milieu of biogenic organic compounds that naturally cycle through the shallow environment. Indeed, virtually all compounds in crude oil and processed petroleum products have been introduced naturally to the shallow environments as oil and gas seepage for millions of years ( NRC, 2002). Even high molecular weight (HMW) polyaromatic compounds were introduced to shallow environments through forest fires and natural coking of crude oil ( Ballentine et al., 1996; O'Malley et al., 1997). The full development of natural microbial enzymatic systems that can utilize HMW hydrocarbons as carbon or energy source attests to the antiquity of hydrocarbon dispersal processes in the environment. The environmental concern is, therefore, primarily due to the rate and spatial scale by which petroleum products are released in modern times, particularly with respect to the environmental sensitivity of some ecosystems to these releases ( Schwarzenbach et al., 1993; Eganhouse, 1997; NRC, 2002).Crude oil is produced by diagenetic and thermal maturation of terrestrial and marine plant and animal materials in source rocks and petroleum reservoirs. Most of the petroleum in use today is produced by thermal and bacterial decomposition of phytoplankton material that once lived near the surface of the world's ocean, lake, and river waters (Tissot and Welte, 1984). Terrestrially derived organic matter can be regionally significant, and is the second major contributor to the worldwide oil inventory ( Tissot and Welte, 1984; Peters and Moldowan, 1993; Engel and Macko, 1993). The existing theories hold that the organic matter present in crude oil consists of unconverted original biopolymers and new compounds polymerized by reactions promoted by time and increasing temperature in deep geologic formations. The resulting oil can migrate from source to reservoir rocks where the new geochemical conditions may again lead to further transformation of the petrogenic compounds. Any subsequent changes in reservoir conditions brought about by uplift, interaction with aqueous fluids, or even direct human intervention (e.g., drilling, water washing) likewise could alter the geochemical makeup of the petrogenic compounds. Much of our understanding of environmental sources and fate of hydrocarbon compounds in shallow environments indeed borrowed from the extensive geochemical and analytical framework that was meticulo

  3. Bioremediation of petroleum hydrocarbon-contaminated ground water: The perspectives of history and hydrology

    Science.gov (United States)

    Chapelle, F.H.

    1999-01-01

    Bioremediation, the use of microbial degradation processes to detoxify environmental contamination, was first applied to petroleum hydrocarbon-contaminated ground water systems in the early 1970s. Since that time, these technologies have evolved in some ways that were clearly anticipated early investigators, and in other ways that were not foreseen. The expectation that adding oxidants and nutrients to contaminated aquifers would enhance biodegradation, for example, has been born out subsequent experience. Many of the technologies now in common use such as air sparging, hydrogen peroxide addition, nitrate addition, and bioslurping, are conceptually similar to the first bioremediation systems put into operation. More unexpected, however, were the considerable technical problems associated with delivering oxidants and nutrients to heterogeneous ground water systems. Experience has shown that the success of engineered bioremediation systems depends largely on how effectively directions and rates of ground water flow can be controlled, and thus how efficiently oxidants and nutrients can be delivered to contaminated aquifer sediments. The early expectation that injecting laboratory-selected or genetically engineered cultures of hydrocarbon-degrading bacteria into aquifers would be a useful bioremediation technology has not been born out subsequent experience. Rather, it appears that petroleum hydrocarbon-degrading bacteria are ubiquitous in ground water systems and that bacterial addition is usually unnecessary. Perhaps the technology that was least anticipated early investigators was the development of intrinsic bioremediation. Experience has shown that natural attenuation mechanisms - biodegradation, dilution, and sorption - limit the migration of contaminants to some degree in all ground water systems. Intrinsic bioremediation is the deliberate use of natural attenuation processes to treat contaminated ground water to specified concentration levels at predetermined points in the aquifer. In current practice, intrinsic bioremediation of petroleum hydrocarbons requires a systematic assessment to show that ambient natural attenuation mechanisms are efficient enough to meet regulatory requirements and a monitoring program to verify that performance requirements are met in the future.

  4. Perfluorinated hydrocarbons used as Ps inhibitors in non-polar solvents

    International Nuclear Information System (INIS)

    Perfluorinated cyclic and linear hydrocarbons appear to be weak Ps inhibitors when used as additives in non-polar solvents. Both types of compounds give rise to a minimum in the o-Ps yield at low solute concentrations. However, the linear solutes, as distinguished from the cyclic ones, also give rise to a second minimum in the o-Ps yield at high concentrations of the solute. The first minimum is due to the formation of molecular anions, upon attachment of spur electrons, which can undergo secondary reactions with fast moving positrons. The second minimum cannot be explained with the present state of knowledge of the interaction between electrons and perfluorocarbons. (Auth.)

  5. Transferable Tight-Binding Potential for Hydrocarbons

    CERN Document Server

    Wang, Y; Wang, Yang

    1994-01-01

    A transferable tight-binding potential has been constructed for heteroatomic systems containing carbon and hydrogen. The electronic degree of freedom is treated explicitly in this potential using a small set of transferable parameters which has been fitted to small hydrocarbons and radicals. Transferability to other higher hydrocarbons were tested by comparison with ab initio calculations and experimental data. The potential can correctly reproduce changes in the electronic configuration as a function of the local bonding geometry around each carbon atom. This type of potential is well suited for computer simulations of covalently bonded systems in both gas-phase and condensed-phase systems.

  6. Activation of hydrocarbons and the octane number

    Science.gov (United States)

    Peschard, Marcel

    1939-01-01

    This report presents an examination of the history of research on engine knocking and the various types of fuels used in the investigations of this phenomenon. According to this report, the spontaneous ignition of hydrocarbons doped with oxygen follows the logarithmic law within a certain temperature range, but not above 920 degrees K. Having extended the scope of investigations to prove hydrocarbons, the curves of the mixtures burned by air should then be established by progressive replacement of pure iso-octane with heptane. Pentane was also examined in this report.

  7. Nitrocarburising in ammonia-hydrocarbon gas mixtures

    DEFF Research Database (Denmark)

    Pedersen, Hanne; Christiansen, Thomas

    2010-01-01

    The present work investigates the possibility of nitrocarburising in ammonia-acetylene-hydrogen and ammoniapropene- hydrogen gas mixtures, where unsaturated hydrocarbon gas is the carbon source during nitrocarburising. Consequently, nitrocarburising is carried out in a reducing atmosphere and straightforward control of the carburizing and nitriding potentials is in principle possible. The nitrocarburising response of unalloyed (ARMCO) Fe was investigated in a thermobalance during controlled nitrocarburising at 580°C. The “cases” obtained on nitrocarburised iron were characterized by reflected light microscopy and X-ray diffraction analysis. It is shown that the use of unsaturated hydrocarbon gas in nitrocarburising processes is a viable alternative to traditional nitrocarburising methods.

  8. Nitrocarburizing in ammonia-hydrocarbon gas mixtures

    DEFF Research Database (Denmark)

    Pedersen, Hanne; Christiansen, Thomas

    2011-01-01

    The present work investigates the possibility of nitrocarburising in ammonia-acetylene-hydrogen and ammonia-propene-hydrogen gas mixtures, where unsaturated hydrocarbon gas is the carbon source during nitrocarburising. Consequently, nitrocarburising is carried out in a reducing atmosphere and straightforward control of the carburising and nitriding potentials is in principle possible. The nitrocarburising response of unalloyed (ARMCO) Fe was investigated in a thermobalance during controlled nitrocarburising at 580°C. The “cases” obtained on nitrocarburised iron were characterized by reflected light microscopy and X-ray diffraction analysis. It is shown that the use of unsaturated hydrocarbon gas in nitrocarburising processes is a viable alternative to traditional nitrocarburising methods.

  9. Chemistry of secondary organic aerosol formation

    Science.gov (United States)

    Yee, Lindsay Diana

    The photooxidation of volatile organic compounds (VOCs) in the atmosphere can lead to the formation of secondary organic aerosol (SOA), a major component of fine particulate matter. Improvements to air quality require insight into the many reactive intermediates that lead to SOA formation, of which only a small fraction have been measured at the molecular level. This thesis describes the chemistry of secondary organic aerosol (SOA) formation from several atmospherically relevant hydrocarbon precursors. Photooxidation experiments of methoxyphenol and phenolic compounds and C12 alkanes were conducted in the Caltech Environmental Chamber. These experiments include the first photooxidation studies of these precursors run under sufficiently low NOx levels, such that RO2 + HO2 chemistry dominates, an important chemical regime in the atmosphere. Using online Chemical Ionization Mass Spectrometery (CIMS), key gas-phase intermediates that lead to SOA formation in these systems were identified. With complementary particle-phase analyses, chemical mechanisms elucidating the SOA formation from these compounds are proposed. Three methoxyphenol species (phenol, guaiacol, and syringol) were studied to model potential photooxidation schemes of biomass burning intermediates. SOA yields (ratio of mass of SOA formed to mass of primary organic reacted) exceeding 25% are observed. Aerosol growth is rapid and linear with the organic conversion, consistent with the formation of essentially non-volatile products. Gas and aerosol-phase oxidation products from the guaiacol system show that the chemical mechanism consists of highly oxidized aromatic species in the particle phase. Syringol SOA yields are lower than that of phenol and guaiacol, likely due to unique chemistry dependent on methoxy group position. The photooxidation of several C12 alkanes of varying structure n-dodecane, 2-methylundecane, cyclododecane, and hexylcyclohexane) were run under extended OH exposure to investigate the effect of molecular structure on SOA yields and photochemical aging. Peroxyhemiacetal formation from the reactions of several multifunctional hydroperoxides and aldehyde intermediates was found to be central to organic growth in all systems, and SOA yields increased with cyclic character of the starting hydrocarbon. All of these studies provide direction for future experiments and modeling in order to lessen outstanding discrepancies between predicted and measured SOA.

  10. BIOGENIC HYDROCARBONS IN THE ATMOSPHERIC BOUNDARY LAYER: A REVIEW

    Science.gov (United States)

    Nonmethane hydrocarbons are ubiquitous trace atmospheric constituents yet they control the oxidation capacity of the atmosphere. Both anthropogenic and biogenic processes contribute to the release of hydrocarbons to the atmosphere. In this manuscript, the state of the science ...

  11. RADIO FREQUENCY ENHANCED DECONTAMINATION OF SOILS CONTAMINATED WITH HALOGENATED HYDROCARBONS

    Science.gov (United States)

    There has been considerable effort in the development of innovative treatment technologies for the clean up of sites containing hazardous wastes such as hydrocarbons and chlorinated hydrocarbons. Typical examples of such waste material are: chlorinated solvents, polychlorinated b...

  12. THE UPTAKE OF AROMATIC AND BRANCHED CHAIN HYDROCARBONS BY YEAST

    Science.gov (United States)

    Studies of the hydrocarbon utilizing yeasts, Candida maltosa and C. lipolytica, have shown that both were capable of reducing recoverable amounts of branched chain and aromatic hydrocarbons in a mixture of naphthalene, tetradecane, hexadecane, pristane (tetra-methylpentadecane). ...

  13. 33 CFR 157.132 - Cargo tanks: Hydrocarbon vapor emissions.

    Science.gov (United States)

    2010-07-01

    ...2010-07-01 false Cargo tanks: Hydrocarbon vapor emissions...ENVIRONMENT RELATING TO TANK VESSELS CARRYING OIL IN...Washing (COW) System on Tank Vessels Design, Equipment...Installation § 157.132 Cargo tanks: Hydrocarbon vapor...

  14. Water and contaminant movement: migration barriers

    International Nuclear Information System (INIS)

    Migration barriers are used in shallow land burial facilities to slow or stop the movement of water and contaminants and are discussed here as a single component embedded in a complex environmental system. Analytical solutions to solute transport equations are used to approximate the behavior of migration barriers and to derive design criteria for control of subsurface water and contaminant migration. Various types of migration barriers are compared and design recommendations are made for shallow land burial trench caps and liners. Needed improvements and suggested field experiments for future designs of migration barriers are then discussed relative to the management of low-level radioactive wastes

  15. Syn-Rift Systems of East Godavari Sub Basin: Its Evolution and Hydrocarbon Prospectivity

    Science.gov (United States)

    Dash, J., Jr.; Zaman, B.

    2014-12-01

    Krishna Godavari (K.G.) basin is a passive margin basin developed along the Eastern coast of India. This basin has a polyhistoric evolution with multiple rift systems. Rift basin exploration has provided the oil and gas industry with almost one third of discovered global hydrocarbon resources. Understanding synrift sequences, their evolution, depositional styles and hydrocarbon prospectivity has become important with recent discovery of the wells, G-4-6,YS-AF and KG-8 in the K.G. offshore basin. The East Godavari subbasin is a hydrocarbon producing basin from synrift and pre-rift sediments, and hence this was selected as the study area for this research. The study has been carried out by utilizing data of around 58 wells (w1-w58) drilled in the study area 25 of which are hydrocarbon bearing with organic thickness varying from 200 m to 600 m. Age data generated by palaentology and palynology studies have been utilized for calibration of key well logs to differentiate between formations within prerift and synrift sediments. The electrologs of wells like resistivity, gamma ray, neutron, density and sonic logs have been utilized for correlation of different formations in all the drilled wells. The individual thicknesses of sand, shale and coal in the formations have been calculated and tabulated. For Golapalli formation, the isopach and isolith maps were generated which revealed that there were four depocentres with input from the north direction. Schematic geological cross sections were prepared using the well data and seismic data to understand the facies variation across the basin. The sedimentological and petrophysical analysis reports and electro log suites were referred to decipher the environment of deposition, the reservoir characteristics, and play types. The geochemical reports [w4 (Tmax)= 455-468 °C; w1 (Tmax) = 467-514 °C; w4(VRO)= 0.65-0.85; w1(VRO)= 0.83-1.13] revealed the source facies, its maturation and migration timings i.e. the petroleum systems. It was concluded these fluvial channel systems constitute the main hydrocarbon play for the Mandapeta and Gollapalli formations and these channel systems if found at a structurally advantageous positions should prove to be good hydrocarbon targets.

  16. H2-rich and Hydrocarbon Gas Recovered in a Deep Precambrian Well in Northeastern Kansas

    International Nuclear Information System (INIS)

    In late 2005 and early 2006, the WTW Operating, LLC (W.T.W. Oil Co., Inc.) no. 1 Wilson well (T.D. = 5772 ft; 1759.3 m) was drilled for 1826 ft (556.6 m) into Precambrian basement underlying the Forest City Basin in northeastern Kansas. Approximately 4500 of the 380,000 wells drilled in Kansas penetrate Precambrian basement. Except for two previous wells drilled into the arkoses and basalts of the 1.1-Ga Midcontinent Rift and another well drilled in 1929 in basement on the Nemaha Uplift east of the Midcontinent Rift, this well represents the deepest penetration into basement rocks in the state to date. Granite is the typical lithology observed in wells that penetrate the Precambrian in the northern Midcontinent. Although no cores were taken to definitively identify lithologies, well cuttings and petrophysical logs indicate that this well encountered basement metamorphic rocks consisting of schist, gneiss, and amphibolitic gneiss, all cut by aplite dikes.The well was cased and perforated in the Precambrian, and then acidized. After several days of swabbing operations, the well produced shows of low-Btu gas, dominated by the non-flammable component gases of nitrogen (20%), carbon dioxide (43%), and helium (1%). Combustible components include methane (26%), hydrogen (10%), and higher molecular-weight hydrocarbons (1%). Although Coveney and others [Am. Assoc. Petroleum Geologists Bull., v. 71, no, 1, p. 39-48, 1987] identified H2-rich gas in two wells located cub>2-rich gas in two wells located close to the Midcontinent Rift in eastern Kansas, this study indicates that high levels of H2 may be a more widespread phenomenon than previously thought. Unlike previous results, the gases in this study have a significant component of hydrocarbon gas, as well as H2, N2, and CO2. Although redox reactions between iron-bearing minerals and groundwater are a possible source of H2 in the Precambrian basement rocks, the hydrocarbon gas does not exhibit the characteristics typically associated with proposed abiogenic hydrocarbon gases from Precambrian Shield sites in Canada, Finland, and South Africa. Compositional and isotopic signatures for gas from the no. 1 Wilson well are consistent with a predominantly thermogenic origin, with possible mixing with a component of microbial gas. Given the geologic history of uplift and rifting this region, and the major fracture systems present in the basement, this hydrocarbon gas likely migrated from source rocks and reservoirs in the overlying Paleozoic sediments and is not evidence for abiogenic hydrocarbons generated in situ in the Precambrian basement

  17. Phase II Interim Report -- Assessment of Hydrocarbon Seepage Detection Methods on the Fort Peck Reservation, Northeast Montana

    Energy Technology Data Exchange (ETDEWEB)

    Monson, Lawrence M.

    2002-04-24

    The following work was performed: (1) collected reconnaissance micro-magnetic data and background field data for Area 1, (2) identified and collected soil sample data in three anomalous regions of Area 1, (3) sampled soils in Northwest Poplar Oil Field, (4) graphed, mapped, and interpreted all data areas listed above, (5) registered for the AAPG Penrose Conference on Hydrocarbon Seepage Mechanisms and Migration (postponed from 9/16/01 until 4/7/02 in Vancouver, B.C.). Results include the identification and confirmation of an oil and gas prospect in the northwest part of Area 1 and the verification of a potential shallow gas prospect in the West Poplar Area. Correlation of hydrocarbon micro-seepage to TM tonal anomalies needs further data analysis.

  18. MIGRATION OF ORACLE HR DATABASE

    CERN Multimedia

    ais.support@cern.ch

    2001-01-01

    Restricted services from 3 to 7 November 2001 Due to the migration of the Oracle HR application to the Web, some services which rely on the application's availability may be disturbed from Friday 2 November at 17:30 until Thursday 8 November at 08:30. Amongst those services: HR Division: records office, recruitment, claims and benefits. FI Division: personnel accounting, advances and claims. ST Division: registration office (access cards). SPL Division: external firm staff records. EP Division: users' office. Experiments' secretariats: PIE, Greybook. Divisional secretariats: externals, internal addresses. All information concerning this migration is available at: http://ais.cern.ch We apologize for any inconvenience and thank you in advance for your understanding.

  19. Nuclide-migration field experiments

    International Nuclear Information System (INIS)

    When considering groundwater flow and radionuclide retention in the complex flow systems that can occur in geologic formations, one has a serious problem in determining if laboratory studies are being performed under conditions appropriate to natural systems. This document is the project plan for a program designed to begin to address these problems. The project is being carried out jointly by the Los Alamos National Laboratory, Sandia National Laboratories, and Argonne National Laboratory. The work has three principal objectives: (1) to develop the experimental, instrumental, and safety techniques necessary to conduct controlled, small-scale radionuclide migration field experiments, including those involving actinides; (2) to use these techniques to define radionuclide migration through rock by performing generic, at-depth experiments under closely monitored conditions; and (3) to determine whether available lithologic, geochemical, and hydrologic properties together with existing or developing transport models are sufficient and appropriate to describe real field conditions

  20. Physicists' Forced Migrations under Hitler

    Science.gov (United States)

    Beyerchen, Alan

    2011-03-01

    When the Nazis came to power in early 1933 they initiated formal and informal measures that forced Jews and political opponents from public institutions such as universities. Some physicists retired and others went into industry, but most emigrated. International communication and contact made emigration a viable option despite the desperate economic times in the Great Depression. Another wave of emigrations followed the annexation of Austria in 1938. Individual cases as well as general patterns of migration and adaptation to new environments will be examined in this presentation. One important result of the forced migrations was that many of the physicists expelled under Hitler played important roles in strengthening physics elsewhere, often on the Allied side in World War II.

  1. Secondary-Progressive MS (SPMS)

    Science.gov (United States)

    ... Secondary-progressive MS (SPMS) Learn More Learn More Research in Secondary-progressive MS (SPMS) Learn More Learn More Frequently ... Learn More Share Smaller Text Larger Text Print Secondary-progressive MS ... SPMS Research in SPMS FAQs about SPMS Discover More Here ...

  2. Improved Live Migration Using Compressed Log Files

    Directory of Open Access Journals (Sweden)

    Rakhi k Raj #1, Getzi Jeba Leelipushpam

    2013-03-01

    Full Text Available Live virtual machine migration is the process of moving virtual machine from one host to other without disturbance of users. Live migration is used in the case of proactive maintenance, power management, load balancing, energy saving. This paper present and design the novel approach to reduce the total migration time and down time during live virtual machine migration by compressed log files transfer. For providing the effective and fast migration of the virtual machine log compression method uses Huffman encoding and to make the migration effective we use the parallel multithreading technique. This method also consumes the less bandwidth during the time of migration and provide more security to the data.

  3. Tracing The Largest Seasonal Migration on Earth

    CERN Document Server

    Wang, Xianwen; Mao, Wenli; Hu, Zhigang; Gu, Li

    2014-01-01

    It is estimated that over 3.6 billion passengers are travelling during the Chinese Spring Festival travel season. They leave their working cities and return their hometowns to enjoy annual family time, and back to cities after the holiday. In this study, with the massive location-based data collected from millions of smartphone users, we propose a novel method to trace the migration flow and explore the migration patterns of Chinese people. From the temporal perspective, we explore the migration trend over time during a 34-days period, about half a month before and after the Spring Festival. From the spatial perspective, the migration directions and routes are estimated and quantified, and the migration flow is visualized. The spatial range of influence of developed regions could be reflected with the destinations of migration, the migration destinations and originations have obvious characteristic of geographical proximity.

  4. Music and Migration: A Transnational Approach

    Directory of Open Access Journals (Sweden)

    Nadia Kiwan

    2011-12-01

    Full Text Available This special issue on the theme of Music and Migration addresses the highly topical theme of migration and the vitality of “cultural diasporas” through the prism of migrating musicians and migrating musical forms. All nine original articles, including our own, engage with broader questions of how new modes of mobility and sociality are borne out of the social, cultural, historical and political interfaces between migration and music. Through a transnational, comparative and multi-level approach to the relationship between migration, movement and music, this special issue focuses on the aesthetic intersections between the local and the global, and between agency and identity. By taking music as its specific focus, the issue seeks to contribute to ongoing theoretical and methodological debates within migration and diaspora studies, including those related to transnational networks, globalization and cultural flows.

  5. Hydrocarbon potential, sequence stratigraphy, and petrographic analysis of the Ferry Lake Anhydrite, Eastern Gulf of Mexico, Southern Mississippi province

    Science.gov (United States)

    Amadi, Faith O.

    The Lower Cretaceous Ferry Lake Anhydrite (FLA) in southern Mississippi is composed of approximately 76 meters (250 feet) of alternating carbonate and evaporite beds. Correlations of well logs indicate rhythmic depositional stacking of carbonate and anhydrite facies. Identification of these small-scale transgressive-regressive cycles, which formed during high-frequency eustatic sea-level fluctuations, is based on stratal geometry, nature of cycle boundaries, and facies stacking patterns. The FLA sequence is divided into eleven high-frequency (FLP-1 to FLP-11), fourth-order parasequences at the southern edge of the Mississippi Interior Salt Basin, and eight high-frequency, fourth-order cycle sets (FLP-1 to FLP-8) approximately 120 kilometers south of the southern rim. Fewer parasequences in the seaward direction result from pinchouts of evaporite beds and interfingering of evaporites with carbonate beds. Classifying FLA into high frequency, fourth-order parasequences provides understanding of reservoir, source, and seal distributions. Pervasive shallow to deep burial diagenetic processes generated pores and fracture-filling calcite and anhydrite cements, resulting from the flow of connate water. The carbonate beds exhibit variable porosity and permeability that range from 0.1 to 14 % and 0.5 to 100.5 and respectively. Fractured porosity constitutes the dominant porosity that resulted from extensive tectonic activities and differential compaction that predates late-stage cementation. Late-stage dissolution of calcite and evaporites along fractures, fossil fragments, and bedding discontinuities are principal to the development of secondary porosity and permeability. Rock-Eval/TOC analysis generates Total organic richness (0.53 -- 1.0%), vitrinite reflectance (0.88 -- 1.16wt %), and Tmax (437 -- 438°C). The rocks have an average thermal alteration index (TAI) value of 3.3. The maturity levels reported for these moderately organic-rich rocks suggest that they are fair to good source rocks. Vitrinite reflectance data and normalized oil content suggest that the rocks are themselves a source, although, some hydrocarbons may have migrated into the system. X-ray diffraction and petrography results suggest the presence of gypsum at the depth of 13,320 ft (4,060 m). Estimating porosity values using neutron log in deep carbonate reservoirs that contain evaporite nodules could have significant porosity and water saturation measurement errors, due to possible occurrence of gypsum and as such should be evaluated mineralogically whenever possible.

  6. Volatile Fuel Hydrocarbons and MTBE in the Environment

    Science.gov (United States)

    Cozzarelli, I. M.; Baehr, A. L.

    2003-12-01

    Petroleum hydrocarbons (hydrocarbons that result from petroleum products such as oil, gasoline, or diesel fuel) are among the most commonly occurring and widely distributed contaminants in the environment. Volatile hydrocarbons are the lighter fraction of the petroleum hydrocarbons and, together with fuel oxygenates, are most often released from crude oil and liquid petroleum products produced from crude oil. The demand for crude oil stems from the world's ever-growing energy need. From 1970 to 1999, primary energy production of the world grew by 76% (Energy Information Administration, 2001), with fossil fuels (crude oil, natural gas, and coal) accounting for ˜85% of all energy produced worldwide (Figure 1). World crude oil production reached a record 68 million barrels (bbl) per day (1.08×1010 L d-1) in 2000. The world's dependence on oil as an energy source clearly is identified as contributing to global warming and worsening air and water quality. (7K)Figure 1. World primary energy production by source from 1970 to 1999 (Energy Information Administration, 2001). Petroleum products are present in Earth's subsurface as solids, liquids, or gases. This chapter presents a summary of the environmental problems and issues related to the use of liquid petroleum, or oil. The focus is on the sources of volatile hydrocarbons and fuel oxygenates and the geochemical behavior of these compounds when they are released into the environment. Although oxygenates currently in commercial use include compounds other than methyl t-butyl ether (MTBE), such as ethanol (ETOH), most of the information presented here focuses on MTBE because of its widespread occurrence. The environmental impact of higher molecular weight hydrocarbons that also originate from petroleum products is described in (Chapter 9.13, Abrajano et al.).Crude oil occurs within the Earth and is a complex mixture of natural compounds composed largely of hydrocarbons containing only hydrogen and carbon atoms. The minor elements of sulfur, nitrogen, and oxygen constitute less than 3% of most petroleum (Hunt, 1996). Releases to the environment occur during the production, transport, processing, storage, use and disposal of these hydrocarbons. The petroleum industry classifies oil naturally occurring in a liquid phase as either conventional oil or nonconventional oil. Conventional oils can be explored and produced by conventional primary and secondary recovery techniques, whereas nonconventional oils, such as heavy oils, tar sands, and synthetic oils, are more difficult to extract from the host rock ( Tissot and Welte, 1984). The history of liquid petroleum usage dates back centuries. Marco Polo described its use as a fuel for lamps in 1291 ( Testa and Winegardner, 2000). In the mid-nineteenth century, Native Americans used crude oil skimmed from creeks and rivers as a medicinal ointment ( Energy Information Administration, 1999). Commercial production in the United States began in 1859, with kerosene production for use in lamps. At the turn of the century, emphasis shifted to gasoline with the invention of the automobile, and in the 1930s and 1940s a substantial market for heating oil developed.In 2000, over 85% of the world's energy came from fossil fuels (Table 1), with oil production alone supplying 40% of that energy (Edwards, 2001). Oil, with its high British Thermal Unit (BTU) density and ease of transport, is the most valuable fuel in the world today, and the demand for world crude oil is ever increasing. Annual world crude-oil demand increased from 22 billion to 28 billion bbl of oil (BBO) ((3.5-4.5)×1012 L) from 1990 to 2000. Increasing population growth and industrialization in developing countries is expected to drive this annual oil demand up 1.5% annually to ˜38 BBO (6.0×1012 L) by 2030. As demand increases and known oil reserves are depleted, more emphasis will be placed on new discoveries and improved recovery technologies. Sources such as tar sands and oil shales are likely to become more important, bringing environmental problems inherent to the production,

  7. Globalization and International Migration Governance

    OpenAIRE

    Wihtol Wenden, Catherine

    2012-01-01

    With an estimated 214 million international migrants and 740 million internal migrants in a world of more than 6 billion inhabitants, migration now affects the whole planet and has become a major international issue. Nearly all countries are concerned by human mobility, as sending, receiving or transit states. Categories of economic, political or family migrants are no longer strictly defined, as the same people may change legal or social status several times in the course of their life. Over...

  8. Incentives and disincentives: international migration.

    Science.gov (United States)

    Bhagwati, J N

    1984-01-01

    International migration is largely controlled by disincentives, or quotas, on immigration rather than checks on emigrations. Societies generally feel they have a right to exclude others from their boundaries, but they also usually feel that they do not have a right to control emigration. The single-planetary approach holds that people have the right to live wherever they like on the planet, and the cosmopolitan-utilitarian approach believes the same for reasons of world efficiency. The current feeling that societies have the right to exclude others may be explained best by territoriality in human animals. People also believe that their culture will be diluted if too many outsiders enter. In many cases, immigration systems cannot really control immigration, as in the cases of long landlocked borders between the US and Mexico and between Bangladesh and Assam. Immigration systems also contain legal loopholes. For example, in the US it is easier to get a student visa and convert to immigrant status than to gain immigrant status directly. Loopholes lead to plugs, which lead in turn to more loopholes. An upsurge in requests for political asylum followed increased restrictions on immigration in Western Europe. The US has investigated foreign aid and foreign investments to Mexico and Haiti to curb the flow of illegal migrants. The author suggests that foreign investments may lead to more migration because of the creation of a new proletariat used to the ways of developed countries. An estimate of what would happen if all immigration control were removed worldwide concludes that efficiency and income distribution would improve worldwide. Most migration from developing to developed countries currently consists of the migration of skilled professionals, the brain drain. The author proposes a tax on these professionals to be paid to the country of origin to compensate them for the loss in education and training. The author summarizes the differences between the West German gastarbeiter system of recruiting workers abroad and the US system of quotas, which favors families and refugees. PMID:12313736

  9. Migration and Transnationalism : Pacific Perspectives

    OpenAIRE

    Tupai Francis, Steve; Lee, Helen

    2009-01-01

    Pacific Islanders have engaged in transnational practices since their first settlement of the many islands in the region. As they moved beyond the Pacific and settled in nations such as New Zealand, the U.S. and Australia these practices intensified and over time have profoundly shaped both home and diasporic communities. This edited volume begins with a detailed account of this history and the key issues in Pacific migration and transnationalism today. The papers that follow present a range ...

  10. Stem cells origin and migration

    OpenAIRE

    Montiel-Eulefi, E; Montiel, JF

    2012-01-01

    Generation, migration and distribution of stem cells throughout the body are a major process in the generation of morphological divergence and evolution in different species of vertebrates. Progenitor cells pass through different compartments during embryonic development and the exposition to different tissue environments stimulates the activation of specific differentiation programs. In this chapter we discuss the origin of different migratory cell populations, such as embryonic stem cells, ...

  11. International Migration, Remittances and Development

    OpenAIRE

    Hasan Mahmud; Md. Abdus Sabur; Sharmin Tamanna

    2009-01-01

    The increasing remittance flows to the labor sending developing countries in recent years have generated huge optimism in the contemporary development discourse about the possibility of development at the grassroots levels which has been an overwhelming challenge for the development actors for decades. However, the realization of such potential proves difficult due to a lack of common understanding of the phenomenon of labor migration and its causes and consequences. This study focuses on the...

  12. Migration and innovation: A survey

    OpenAIRE

    Rashidi, Sheida; Pyka, Andreas

    2013-01-01

    In a world characterized by competition on a global scale, persistent structural change driven by innovation and aging societies in industrialized economies, also the competition for the best talents on the labour markets becomes global and more intensive. Therefore it is not surprising that old-fashioned brain drain explanations for migration are no longer convincing. In the knowledge-based economies of the 21st centuries the ideas of brain circulation and international (diaspora) innovation...

  13. Migration and innovation : a survey

    OpenAIRE

    Rashidi, Sheida; Pyka, Andreas

    2013-01-01

    In a world characterized by competition on a global scale, persistent structural change driven by innovation and aging societies in industrialized economies, also the competition for the best talents on the labour markets becomes global and more intensive. Therefore it is not surprising that old-fashioned brain drain explanations for migration are no longer convincing. In the knowledge-based economies of the 21st centuries the ideas of brain circulation and international (diaspora) innovation...

  14. ILLEGAL MIGRATION-CONCEPTUAL DELIMITATIONS

    Directory of Open Access Journals (Sweden)

    CRISTINA FLORINA POPESCU (PANAIT

    2013-05-01

    Full Text Available Illegal migration is a mobile phenomenon, which ignores national borders, a threat that originates outside the community and extends to Western societies. This phenomenon is becoming larger and irregular migrants are often in a precarious situation and exposed to the criminals involved in various manifestations of organized crime. The future risk factors of the illegal migration are the demographic bomb, because the population is decreasing in European countries and increasing rapidly in poorer countries, droughts, floods, deforestation, that cause conflicts between climate refugees , extreme poverty, totalitarian regimes, epidemics, can trigger millions of people, the elderly and the working population imbalance which leads to the permanent import of immigrants To combat this phenomenon, states must engage and cooperate with each other. Measures taken by states must balance their integration policy for immigrants, legally residents and asylum policy to comply with international conventions. Also, states must adopt anti-immigrant policies, consisting of subordination visa policy to the interests of international security and exchange of information and, not least, to continue the Schengen process, as a value of humanitarian law applied in the field. The aim of the research is to characterize this dangerous phenomenon for the society and the goal is to identify strategies to combat illegal migration.

  15. Field investigation with regard to the impermeability of clay formations. Helium-4 soil gas surveys in sedimentary basins as a tentative study of secondary permeability in clayey sequences

    International Nuclear Information System (INIS)

    This report deals with a tentative study for the detection of the secondary permeability in clayey formations conducted in several sedimentary basins in Central Italy, by means of geochemical methods. The main purposes are: to try a geochemical method, based on the distribution of deep origin gases in soil gas (4He and 222Rn), to detect buried fault systems and to study the permeability of clay as a potential migration pathway for nuclides of radioactive waste deposits; to verify the effectiveness of this method for the selection of suitable sites for radwaste disposal. This research programme consists in a collaboration between ENEA and the University of Rome within the communitarian programme for the disposal of high level and long-live radwaste. Investigations concerned sedimentary basins filled by sand-clay formations 1000-2000 meters thick and characterized by different tectonic: Era and Chiani-Paglia Valleys (Tuscany and North Latium), structural trenches due to extensive tectonics along the tyrrhenian edge, and Vasto region, a basin in the 'Adriatic foretrench', characterized by compressive tectonics. The investigated areas are near or directly correspond to geothermal fields or to hydrocarbon reservoirs supplying gases which may migrate upward along fractures. Almost 4000 soil gas samples were collected in the three surveyed areas; the sampling density was of about 1.5 points / km2, normally used in the regional scale surveys. The obtained results show that the observed helium anomalies are distributed or elongated according to the main tectonic features of the substratum (fault systems, fractures, deep structures); the magnitude of anomalies seems to correlate with the nature of the deep gas reservoir (i.e. oil in Vasto), geothermal reservoir in the Paglia valley. These observations seem to confirm that the presence of deep origin gases in soils is controlled by tectonics. Clay thickness does not significantly control the uprising of deep gases: in fact a few meters of unfractured clay can constitute an efficient barrier even with regard to the migration of the most mobile element (He). 38 refs., 36 figs., 6 tabs

  16. 40 CFR 721.4380 - Modified hydrocarbon resin.

    Science.gov (United States)

    2010-07-01

    ...2010-07-01 false Modified hydrocarbon resin. 721.4380 Section 721.4380 ...Substances § 721.4380 Modified hydrocarbon resin. (a) Chemical substance and significant...identified generically as a modified hydrocarbon resin (P-91-1418) is subject to...

  17. POTENTIAL HYDROCARBON PRODUCING SPECIES OF WESTERN GHATS, TAMIL, NADU, INDIA

    Science.gov (United States)

    The decline in the world supplies of hydrocarbons has lead to the search for alternate sources of fuel and chemicals. Plant species are potential sources of hydrocarbons. Large-scale screening of plants growing in the Western Ghats, Tamil Nadu, India was conducted to assess the hydrocarbon productio...

  18. Parameterising secondary organic aerosol from ?-pinene using a detailed oxidation and aerosol formation model

    OpenAIRE

    J.-F. Müller; S. Compernolle; K. Ceulemans

    2011-01-01

    A new 10-product parameter model for ?-pinene secondary organic aerosol (SOA) is presented, based on simulations with the detailed model BOREAM (Biogenic hydrocarbon Oxidation and Related Aerosol formation Model). The parameterisation takes into account the influence of temperature, type of oxidant, NOx-regime, photochemical ageing and water uptake, and is suitable for use in global chemistry transport models. BOREAM is validated against recent photooxidation smog chamber experiments, for wh...

  19. Wireless sensing on surface hydrocarbon production systems

    International Nuclear Information System (INIS)

    The use of wireless sensor networks for monitoring and optimising the performance of surface hydrocarbon production systems is reported. Wireless sensor networks are shown to be able to produce comprehensively instrumented XTs and other equipment that generate the data required by Intelligent Oilfield systems. The information produced by such systems information can be used for real-time operational control, production optimization and troubleshooting.

  20. Modeling Subsurface Transport of Petroleum Hydrocarbons

    Science.gov (United States)

    This U.S. EPA website contains information on the modeling of subsurface transport of petroleum hydrocarbons and other contaminants. There are a few course modules on the fate and transport of contaminants. There are also OnSite on-line calculators for site-specific assessment calculations.

  1. Transformations of aromatic hydrocarbons over zeolites.

    Czech Academy of Sciences Publication Activity Database

    Voláková, Martina; Žilková, Nad?žda; ?ejka, Ji?í

    2008-01-01

    Ro?. 34, 5-7 (2008), s. 439-454. ISSN 0922-6168 R&D Projects: GA ?R GA203/05/0197; GA AV ?R 1QS400400560; GA AV ?R KJB4040402 Institutional research plan: CEZ:AV0Z40400503 Keywords : aromatic hydrocarbons * zeolites * alkylation Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 0.514, year: 2008

  2. Source identification of hydrocarbons following environmental releases

    International Nuclear Information System (INIS)

    Methods of identifying the sources of hydrocarbon contaminations were discussed in this PowerPoint presentation. Laboratories analyze for total petroleum hydrocarbons (TPH) by obtaining chromatograms of observed products. However, many petroleum products provide similar chromatograms. Several independent lines of evidence are needed for the purposes of accurate determination in legal applications. A case study of a lube oil plant spill was used to demonstrate the inconclusiveness of chromatograms and the need to determine petroleum biomarkers. Terpane, sterane, triaromatic sterane, isoprenoid, and alkylcyclohexane analyses were conducted to differentiate between the hydrocarbon samples. The analysis methods are being used with various soil, water, and crab species samples from the BP oil spill. Oil found at the different sites must be directly related to the spill. However, there are 3858 oil and gas platforms currently operating in the Gulf of Mexico. Ratios of biomarkers and polycyclic aromatic hydrocarbons (PAHs) are being developed to generate weight of evidence. A critical difference analysis was also presented. tabs., figs.

  3. Task 8: Evaluation of hydrocarbon potential

    Energy Technology Data Exchange (ETDEWEB)

    Cashman, P.H.; Trexler, J.H. Jr.

    1994-12-31

    Our studies focus on the stratigraphy of Late Devonian to early Pennsylvanian rocks at the NTS, because these are the best potential hydrocarbon source rocks in the vicinity of Yucca Mountain. In the last year, our stratigraphic studies have broadened to include the regional context for both the Chainman and the Eleana formations. New age data based on biostratigraphy constrain the age ranges of both Chainman and Eleana; accurate and reliable ages are essential for regional correlation and for regional paleogeographic reconstructions. Source rock analyses throughout the Chainman establish whether these rocks contained adequate organic material to generate hydrocarbons. Maturation analyses of samples from the Chainman determine whether the temperature history has been suitable for the generation of liquid hydrocarbons. Structural studies are aimed at defining the deformation histories and present position of the different packages of Devonian - Pennsylvanian rocks. This report summarizes new results of our structural, stratigraphic and hydrocarbon source rock potential studies at the Nevada Test Site and vicinity. Stratigraphy is considered first, with the Chainman Shale and Eleana Formation discussed separately. New biostratigraphic results are included in this section. New results from our structural studies are summarized next, followed by source rock and maturation analyses of the Chainman Shale. Directions for future work are included where appropriate.

  4. Site characterization and petroleum hydrocarbon plume mapping

    Energy Technology Data Exchange (ETDEWEB)

    Ravishankar, K. [Harding Lawson Associates, Houston, TX (United States)

    1996-12-31

    This paper presents a case study of site characterization and hydrocarbon contamination plume mapping/delineation in a gas processing plant in southern Mexico. The paper describes innovative and cost-effective use of passive (non-intrusive) and active (intrusive) techniques, including the use of compound-specific analytical methods for site characterization. The techniques used, on a demonstrative basis, include geophysical, geochemical, and borehole drilling. Geochemical techniques used to delineate the horizontal extent of hydrocarbon contamination at the site include soil gas surveys. The borehole drilling technique used to assess the vertical extent of contamination and confirm geophysical and geochemical data combines conventional hollow-stem auguring with direct push-probe using Geoprobe. Compound-specific analytical methods, such as hydrocarbon fingerprinting and a modified method for gasoline range organics, demonstrate the inherent merit and need for such analyses to properly characterize a site, while revealing the limitations of noncompound-specific total petroleum hydrocarbon analysis. The results indicate that the techniques used in tandem can properly delineate the nature and extent of contamination at a site; often supplement or complement data, while reducing the risk of errors and omissions during the assessment phase; and provide data constructively to focus site-specific remediation efforts. 7 figs.

  5. Microbial degradation of petroleum hydrocarbons in soil

    Directory of Open Access Journals (Sweden)

    Kupka Daniel

    1997-09-01

    Full Text Available The abilities of microorganisms to mineralize a wide range of pollutants are well known. Biological processes for the removal of crude oil hydrocarbons from environment are attractive because they consume less energy than conventional physico-chemical processes and offer possibilities for recycling chemicals in the framework of integrated system.

  6. Microbial degradation of petroleum hydrocarbons in soil

    OpenAIRE

    Kupka Daniel

    1997-01-01

    The abilities of microorganisms to mineralize a wide range of pollutants are well known. Biological processes for the removal of crude oil hydrocarbons from environment are attractive because they consume less energy than conventional physico-chemical processes and offer possibilities for recycling chemicals in the framework of integrated system.

  7. Taxation on mining and hydrocarbon investments

    Directory of Open Access Journals (Sweden)

    Beatriz De La Vega Rengifo

    2014-07-01

    Full Text Available This article comments the most important aspects of the tax treatment applicable to investments of mining and oil and gas industry. The document highlights the relevant tax topics of the general tax legislation(Income Tax Law and the special legislation of both industries (General Mining Law and Hydrocarbons Organic Law.

  8. Forensic analysis of hydrocarbons in freshwater sediment

    International Nuclear Information System (INIS)

    A Pembina Pipeline Corporation crude oil pipeline ruptured in July 2000 in northeastern British Columbia, releasing 950 cubic metres of product into the Pine River which later exhibited the presence of polycyclic aromatic hydrocarbons (PAH). Since baseline data on the sediment quality of the river was absent, a study was conducted to determine if the river system had returned to pre-spill conditions. PAH samples were analyzed and the ratios between PAHs known as weathering covariants were computed. It was found that in most cases, the ratios did not match the ratios from the spilled oil, but they matched those of coal samples collected in the Pine River Valley. The study demonstrates that high-energy streams such as the Pine River have a capacity to self-clean. Spilled hydrocarbons can be removed quickly by the continuous re-suspension, aeration and transport of sediments. Dispersion and biodegradation of the hydrocarbons occur readily through these mechanisms. In the Pine River, an increasingly complex PAH mixture was found in the sediment at increasing distance from the spill site. Fingerprinting methods were used to identify hydrocarbon contaminant sources in marine sediments after the spill. 9 refs., 2 tabs., 9 figs

  9. Micropatterned Protective Membranes Inhibit Lens Epithelial Cell Migration in Posterior Capsule Opacification Model

    Science.gov (United States)

    Magin, Chelsea M.; May, Rhea M.; Drinker, Michael C.; Cuevas, Kevin H.; Brennan, Anthony B.; Reddy, Shravanthi T.

    2015-01-01

    Purpose To evaluate the ability of Sharklet (SK) micropatterns to inhibit lens epithelial cell (LEC) migration. Sharklet Technologies, Inc. (STI) and InSight Innovations, LLC have proposed to develop a Sharklet-patterned protective membrane (PM) to be implanted in combination with a posterior chamber intraocular lens (IOL) to inhibit cellular migration across the posterior capsule, and thereby reduce rates of posterior capsular opacification (PCO). Methods A variety of STI micropatterns were evaluated versus smooth (SM) controls in a modified scratch wound assay for the ability to reduce or inhibit LEC migration. The best performing topography was selected, translated to a radial design, and applied to PM prototypes. The PM prototypes were tested in an in vitro PCO model for reduction of cell migration behind an IOL versus unpatterned prototypes and IOLs with no PM. In both assays, cell migration was analyzed with fluorescent microscopy. Results All SK micropatterns significantly reduced LEC migration compared with SM controls. Micropatterns that protruded from the surface reduced migration more than recessed features. The best performing micropattern reduced LEC coverage by 80%, P = 0.0001 (ANOVA, Tukey Test). Micropatterned PMs reduced LEC migration in a PCO model by 50%, P = 0.0005 (ANOVA, Tukey Test) compared with both IOLs with no PM and IOLs with SM PMs. Conclusions Collectively, in vitro results indicate the implantation of micropatterned PMs in combination with posterior chamber IOLs could significantly reduce rates of clinically relevant PCO. This innovative technology is a globally accessible solution to high PCO rates. Translational Relevance A novel IOL incorporating the SK micropattern in a membrane design surrounding the optic may help increase the success of cataract surgery by reducing secondary cataract, or PCO. PMID:25883876

  10. An integrative review of the role of remittances in international nurse migration

    Directory of Open Access Journals (Sweden)

    Squires A

    2014-12-01

    Full Text Available Allison Squires,1 Angela Amico2 1College of Nursing, 2Global Institute of Public Health, New York University, New York, NY, USA Abstract: This review seeks to understand the role of remittances in international nurse migration within the context of three theories of international migration: equilibrium approaches, social networks, and globalization. To analyze the phenomenon, an integrative review of the literature was conducted. Search terms sought articles discussing, either directly or indirectly, remittances and international nurse migration. The initial search returned 369 articles, and further screening decreased the total to 65. Full text screening reduced the final number for the analysis to 48. A directed content analysis structured the analytic approach by examining how authors discussed remittances in the content and context of the paper. The final analysis showed the majority of papers were policy analyses (five; opinion papers, reviews, or editorials that indirectly discussed remittances (27; or were qualitative and quantitative studies (16, either with primary data collection (14 or secondary data analyses (two. Overall, a nurse’s individual motivation for sending remittances home stemmed from familial factors but was never a primary driver of migration. Domestic labor market factors were more likely to drive nurses to migrate. The nurse’s country of origin also was a factor in the remittance dynamic. The identity of the author of the paper played a role in how they discussed remittances in the context of international nurse migration. The three theories of migration helped explain various aspects of the role of remittances in international nursing migration. While the phenomenon has changed since the 2008 global economic crisis and the passing of the World Health Organization’s Global Code of Practice on the International Recruitment of Health Personnel in 2010, future research around the role of remittances needs to consider the confluence of gender, social, political, labor market, and economic dynamics, and not just view the phenomenon from an individual lens. Keywords: nursing, health care worker, remittance

  11. Impact, regulation and health policy implications of physician migration in OECD countries

    Directory of Open Access Journals (Sweden)

    Simoens Steven

    2004-07-01

    Full Text Available Abstract Background In the face of rising demand for medical services due to ageing populations, physician migration flows are increasingly affecting the supply of physicians in Organisation for Economic Co-operation and development (OECD countries. This paper offers an integrated perspective on the impact of physician migration on home and host countries and discusses international regulation and policy approaches governing physician migration. Methods Information about migration flows, international regulation and policies governing physician migration were derived from two questionnaires sent to OECD countries, a secondary analysis of EUROSTAT Labour Force Surveys, a literature review and official policy documents of OECD countries. Results OECD countries increasingly perceive immigration of foreign physicians as a way of sustaining their physician workforce. As a result, countries have entered into international agreements regulating physician migration, although their success has been limited due to the imposition of licensing requirements and the protection of vested interests by domestic physicians. OECD countries have therefore adopted specific policies designed to stimulate the immigration of foreign physicians, whilst minimising its negative impact on the home country. Measures promoting immigration have included international recruitment campaigns, less strict immigration requirements and arrangements that foster shared learning between health care systems. Policies restricting the societal costs of physician emigration from developing countries such as good practice guidelines and taxes on host countries have not yet produced their expected effect or in some cases have not been established at all. Conclusions Although OECD countries generally favour long-term policies of national self-sufficiency to sustain their physician workforce, such policies usually co-exist with short-term or medium-term policies to attract foreign physicians. As this is likely to continue, there is a need to create a global framework that enforces physician migration policies that confer benefits on home and host countries. In the long term, OECD countries need to put in place appropriate education and training policies rather than rely on physician migration to address their future needs.

  12. Electron irradiation-enhanced water and hydrocarbon adsorption in EUV lithography devices

    Energy Technology Data Exchange (ETDEWEB)

    Al-Ajlony, A., E-mail: aalajlon@purdue.edu; Kanjilal, A.; Catalfano, M.; Harilal, S.S.; Hassanein, A.

    2014-01-15

    The accumulation of water and hydrocarbons molecules on pure Au smooth surfaces were monitored during 100 eV electron bombardment at various beam current levels. Our studies showed that these low energy electrons could accelerate the physical adsorption processes of the gaseous contaminant molecules on the mirror surface. The 100 eV electron beam was used to provide a rough simulation of the secondary electrons generated during the interaction between the EUV beam at 13.5 nm wavelength and the mirror surface in an EUVL device. The adsorption enhancement phenomenon was explained in accordance with Langmuir's Adsorption model by the increase of the sticking coefficient of adsorbed molecules onto the mirror surface. We have also shown that a positive biasing of the top of mirror surface can be used for preventing the secondary electron emission from the mirror surface.

  13. Microbe-dependent lymphatic migration of neutrophils modulates lymphocyte proliferation in lymph nodes.

    Science.gov (United States)

    Hampton, Henry R; Bailey, Jacqueline; Tomura, Michio; Brink, Robert; Chtanova, Tatyana

    2015-01-01

    Neutrophil recruitment to the site of injury is an essential first step of an anti-bacterial response. However, little is known about the basis for and relevance of neutrophil migration from inflamed tissue into lymphoid organs. We established a photoconversion-based system to monitor the fate of neutrophils recruited to inflamed skin. While neutrophils are efficiently recruited to sites of both microbial and sterile lesions, subsequent re-localization to draining lymph nodes happens only when bacteria are present in the primary lesion. Skin egress of neutrophils occurs via lymphatic vessels and is dependent on CD11b and CXCR4 but not CCR7. Neutrophils are the predominant immune cell to migrate from inflamed skin into lymph nodes where they augment lymphocyte proliferation. Furthermore, inhibition of neutrophil migration from skin reduces T-cell proliferation in draining lymph nodes. Thus neutrophils mediate rapid cellular communication between the initial injury site and secondary lymphoid organs and modulate immune responsiveness. PMID:25972253

  14. Wetting and superhydrophobic properties of PECVD grown hydrocarbon and fluorinated-hydrocarbon coatings

    International Nuclear Information System (INIS)

    Wetting characteristics of micro-nanorough substrates of aluminum and smooth silicon substrates have been studied and compared by depositing hydrocarbon and fluorinated-hydrocarbon coatings via plasma enhanced chemical vapor deposition (PECVD) technique using a mixture of Ar, CH4 and C2F6 gases. The water contact angles on the hydrocarbon and fluorinated-hydrocarbon coatings deposited on silicon substrates were found to be 72 deg. and 105 deg., respectively. However, the micro-nanorough aluminum substrates demonstrated superhydrophobic properties upon coatings with fluorinated-hydrocarbon providing a water contact angle of ?165 deg. and contact angle hysteresis below 2 deg. with water drops rolling off from those surfaces while the same substrates showed contact angle of 135 deg. with water drops sticking on those surfaces. The superhydrophobic properties is due to the high fluorine content in the fluorinated-hydrocarbon coatings of ?36 at.%, as investigated by X-ray photoelectron spectroscopy (XPS), by lowering the surface energy of the micro-nanorough aluminum substrates.

  15. Green Methodologies to Test Hydrocarbon Reservoirs

    Directory of Open Access Journals (Sweden)

    Francesca Verga

    2010-01-01

    Full Text Available Problem statement: The definition and the economic viability of the best development strategy of a hydrocarbon reservoir mainly depend on the quantity and type of fluids and on the well productivity. Well testing, consisting in producing hydrocarbon to the surface while measuring the pressure variations induced in the reservoir, has been used for decades to determine the fluid nature and well potential. In exploration and appraisal scenarios the hydrocarbons produced during a test are flared, contributing to the emissions of greenhouse gases. Approach: Due to more stringent environmental regulations and a general need for reduced operating expenses, the current industry drivers in today?s formation evaluation methodologies demand short, safe, cost-effective and environmentally friendly test procedures, especially when conventional tests are prohibitively expensive, logistically not feasible or no surface emissions are allowed. Different methods have been proposed or resuscitated in the last years, such as wireline formation tests, closed chamber tests, production/reinjection tests and injection tests, as viable alternatives to conventional well testing. Results: While various short-term tests, test procedures and interpretation methods are apparently available for conducting successful tests without hydrocarbon production at the surface, clarity is lacking for specific applications of these techniques. An attempt to clarify advantages and limitations of each methodology, particularly with respect to the main testing target is pursued in this study. Specific insight is provided on injection testing, which is one of the most promising methodology to replace traditional well testing in reservoir characterization, except for the possibility to sample the formation fluids. Conclusion/Recommendations: Not a single one method but a combination of more methodologies, in particular injection testing and wireline formation testing, is the most promising strategy to achieve all the targets of a conventional well testing with no surface hydrocarbon production, increased safety during operations and reduction of the testing costs

  16. Migration into the Welfare State: Tax and Migration Competition

    OpenAIRE

    Razin, Assaf

    2013-01-01

    In this paper I provide some support to the Tiebout hypothesis. It suggests that when a group of host countries faces an upward supply of immigrants, tax competition does not indeed lead to a race to the bottom; competition may lead to higher taxes than coordination. We identify a fiscal externality (fiscal leakage) that causes tax rates (on both labor and capital), and the volume of migration (of both skill types), to be higher in the competitive regime than in the coordinated regime. If the...

  17. Tracking migrating birds : patterns and processes of migration

    DEFF Research Database (Denmark)

    Willemoes, Mikkel

    2013-01-01

    Migratory movements of birds has always fascinated man and led to many questions concerning the ecological drivers behind, the necessary adaptations and the navigational abilities required. However, especially for the long-distance migrants, basic descriptions of their movements are still lacking and many experiments are only becoming possible with the current development of tracking technologies. During this thesis work I have been tracking the poorly known movements of several species of long-distance migrants and document highly complex migration patterns. In three manuscripts these movements were related to the yearly progression of an environmental surrogate for food availability along the course of migration. In one species, with multiple, different non-breeding staging sites, environmental conditions explain movements well and also how yearly differences explain differences in timing. In another species, environmental conditions are not a good predictor of movements, and possibly effects of timingconstraints or food type play a role. Two manuscripts focus on the effects of human-induced habitat alterations on migratory behaviour. One compares the movements of partial migrants in urban habitats with those in rural habitats. Some species have decreased the frequency of migrants and migration distance in urban environments, and others have not. The other manuscript describes the small scale movements of three different Palaearctic migrants during winter in Africa in a farmland habitat and a forest reserve. In the degraded habitat all species used more space, although the consequence on bird density is less clear. Two manuscripts relate the migratory movements of a long-distance migrant with models of navigation. One compares model predictions obtained by simulation with actual movements, and conclude that the currently believed theoretical framework is insufficient to explain the observed performance. The other study investigates the ability of a displaced experienced migrant to navigate back to the normal migration route. It documents the capability, but also finds interesting patterns in when and where the bird compensated for the displacement. The last paper investigates effects of habitat shading on the performance of light-level based geolocation and compares experimental data with data from real tracking studies. This illustrates some of the potential problems and limitations of geolocation by light.

  18. Application of pre-stack reverse time migration based on FWI velocity estimation to ground penetrating radar data

    Science.gov (United States)

    Liu, Sixin; Lei, Linlin; Fu, Lei; Wu, Junjun

    2014-08-01

    Reverse-time migration (RTM) is used for subsurface imaging to handle complex velocity models including steeply dipping interfaces and dramatic lateral variations and promises better imaging results compared to traditional migration method such as Kirchhoff migration algorithm. RTM has been increasingly used in seismic surveys for hydrocarbon resource explorations. Based on the similarity of kinematics and dynamics between electromagnetic wave and elastic wave, we develop pre-stack RTM method and apply it to process ground penetrating radar (GPR) data. Finite-difference time domain (FDTD) numerical method is used to simulate the electromagnetic wave propagation including forward and backward extrapolations, the cross-correlation imaging condition is used to obtain the final image. In order to provide a velocity model with relatively higher accuracy as the initial velocity model for RTM, we apply a full waveform inversion (FWI) in time domain to estimate the subsurface velocity structure based on reflection radar data. For testing the effectiveness of the algorithm, we have constructed a complex geological model, common-offset radar data and common-shot profile (CSP) radar reflection data are synthesized. All data are migrated with traditional Kirchhoff migration method and pre-stack RTM method separately, the migration results from pre-stack RTM show better coincidence with the true model. Furthermore, we have performed a physical experiment in a sandbox where a polyvinyl chloride (PVC) box is buried in the sand, the obtained common-offset radar data and common-shot radar data are migrated by using Kirchhoff migration method and pre-stack RTM algorithm separately, the pre-stack RTM result shows that RTM algorithm could get better imaging results.

  19. Framboidal magnetic minerals and their possible association to hydrocarbons: La Victoria oil field, southwestern Venezuela

    Directory of Open Access Journals (Sweden)

    L. Colmenares

    1999-02-01

    Full Text Available Magnetic contrasts observed in aeromagnetic studies and in surface samples above oil fields have been attributed to the presence of secondary magnetic minerals produced by a reducing environment that has been induced by the underlying reservoir. However, an unequivocal relationship between these anomalies and the presence of hydrocarbons has not yet been established. We report rock magnetic and magnetic mineralogy results of a preliminary study carried out in drilling fines at different depth levels from three oil wells at La Victoria oil field. Profiles of magnetic susceptibility (MS and bulk magnetization (|M|, corresponding to the first 1500 meters are complemented by studies of X-rays diffraction, Electronic Microscopy (Scanning and Transmission, thermoremanence and Isothermal Remanent Magnetization acquisition curves, and thermal demagnetization of composite IRMs. There is a higher concentration of spherical aggregates (framboids of submicronic magnetic minerals in levels with conspicuous peaks of MS and |M| values. If such aggregates represent the authigenic outcome of near-surface reduction caused by hydrocarbon seepage, these results could establish a link between the contrast of magnetic properties and the presence of hydrocarbons.

  20. Late ventriculo-atrial shunt migration leading to pericardial cerebrospinal fluid effusion and cardiac tamponade

    OpenAIRE

    Mastroianni, Ciro; Chauvet, Dorion; Ressencourt, Olivier; Kirsch, Matthias

    2012-01-01

    We present the case of a patient with cardiac tamponade secondary to late intrapericardial migration of a disrupted ventriculo-atrial shunt (VAS). A 48-year old woman was referred for cardiac tamponade. She had a history of congenital hydrocephalus with implantation of a VAS (Codman®) in 1994. The initial neurological examination was normal. Tomodensitometry showed a discontinuity of the VAS at the cervical level with its distal part floating in the pericardium. Immediate surgery through ste...

  1. Migration and segregation phenomena of a silicone additive in a multilayer organic coating

    OpenAIRE

    Hinder, SJ; Lowe, C; Maxted, JT; Watts, JE

    2005-01-01

    The migration and segregation of a minor silicone containing additive in a multilayer, organic coating system has been investigated by X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). The silicone containing additive employed was the most compatible thermally stable, polyester modified poly(dimethyl siloxane) (PDMS) flow agent. A polyester/polyurethane (PU) based primer and a poly(vinylidene difluoride) (PVdF) based topcoat on an aluminium ...

  2. Upward Migration of Distal Ventriculoperitoneal Shunt Catheter into the Heart: Case Report

    OpenAIRE

    Chong, Jong Yun; Kim, Jae Min; Cho, Dong Charn; KIM, CHOONG HYUN

    2008-01-01

    Ventriculoperitoneal (VP) shunt is commonly and effectively used to treat hydrocephalus. Intracardiac migration of the shunt catheter is a rare complication. A 68-year-old woman underwent ventriculoperitoneal shunting for hydrocephalus secondary to subarachnoid hemorrhage due to anterior communicating artery aneurysm rupture. Two weeks after the shunt surgery, she had suffered from the abdominal pain. Plain chest x-rays, computed tomography, and echocardiography revealed the distal catheter w...

  3. SMOG CHAMBER STUDIES OF SECONDARY ORGANIC AEROSOLS FROM IRRADIATED HYDROCARBONS UNDER AMBIENT CONDITIONS

    Science.gov (United States)

    Understanding the physics and chemistry of aerosols is fundamental to evaluating health risks and developing and evaluating atmospheric models. However, as noted in a recent NRC report only about 10% of the organics in PM2.5 have been identified. A significant portion of the un...

  4. Secondary victims of rape

    DEFF Research Database (Denmark)

    Christiansen, Dorte MØlgaard; Bak, Rikke

    2012-01-01

    Rape is often a very traumatic experience, which affects not only the primary victim (PV) but also his/her significant others. Studies on secondary victims of rape are few and have almost exclusively studied male partners of female rape victims. This study examined the impact of rape on 107 secondary victims, including family members, partners, and friends of male and female rape victims. We found that many respondents found it difficult to support the PV and that their relationship with the PV was often affected by the assault. Furthermore, the sample showed significant levels of traumatization, and it was estimated that approximately one quarter of the respondents suffered from posttraumatic stress syndrome (PTSD). Degree of traumatization was associated with a more recent assault, higher efforts to support the PV, recurrent thoughts about having been able to prevent the assault, a lack of social support for the respondent, and feeling let down by others. The respondents were generally interested in friend-, family-, and partner-focused interventions, particularly in receiving education about how best to support a rape victim

  5. Migration policy, illegal migrants, self-selection and brain drain

    OpenAIRE

    Pires, Armando Jose? Garcia

    2008-01-01

    We compare two migration policies: an open migration policy, where all migrants can migrate legally; and a selective migration policy, where migrants are selected according to skills. We show that since the selective migration policy can create illegal migration, it has the following effects relatively to the open migration policy: (1) it weakens the chances of a positive self-selection of skilled migrants; (2) it reduces the possibility of a beneficial brain gain; and (3) it dampens the effe...

  6. Globalisation and international migration in Asia.

    Science.gov (United States)

    Hugo, G

    1998-03-01

    "The present paper attempts to summarise the major contemporary trends in international migration in Asia and how this is related to the rapid demographic transition occurring across most of the region. The diversity of types of mobility is one of the striking features of Asian international migration and developments in each major type [are] discussed in the paper. It is then argued that there are elements within the Asian migration system that give it a momentum which to some extent operates outside of the influence of economic and political trends. Finally some emerging issues in Asian international migration are briefly addressed. These include the scale and effects of remittances, the feminisation of migration, undocumented migration, increasing government involvement and brain drain issues." (EXCERPT) PMID:12293967

  7. Hydrous pyrolysis/oxidation process for in situ destruction of chlorinated hydrocarbon and fuel hydrocarbon contaminants in water and soil

    Science.gov (United States)

    Knauss, Kevin G. (Livermore, CA); Copenhaver, Sally C. (Livermore, CA); Aines, Roger D. (Livermore, CA)

    2000-01-01

    In situ hydrous pyrolysis/oxidation process is useful for in situ degradation of hydrocarbon water and soil contaminants. Fuel hydrocarbons, chlorinated hydrocarbons, polycyclic aromatic hydrocarbons, petroleum distillates and other organic contaminants present in the soil and water are degraded by the process involving hydrous pyrolysis/oxidation into non-toxic products of the degradation. The process uses heat which is distributed through soils and water, optionally combined with oxygen and/or hydrocarbon degradation catalysts, and is particularly useful for remediation of solvent, fuel or other industrially contaminated sites.

  8. Migrating Applications to IPv6

    CERN Document Server

    York, Dan

    2011-01-01

    If IPv6 is to be adopted on a large scale, the applications running on desktop systems, laptops, and even mobile devices need to work just as well with this protocol as they do with IPv4. This concise book takes you beyond the network layer and helps you explore the issues you need to address if you are to successfully migrate your apps to IPv6. It's ideal for application developers, system/network architects, product managers, and others involved in moving your network to IPv6. Explore changes you need to make in your application's user interfaceMake sure your application is retrieving corre

  9. Hydrocarbon systems of Northeastern Venezuela: plate through molecular scale-analysis of the genesis and evolution of the Eastern Venezuela Basin

    Energy Technology Data Exchange (ETDEWEB)

    Summa, L.L.; Richardson, M. [ExxonMobil Upstream Research Co., Houston, TX (United States); Goodman, E.D.; Norton, I.O.; Green, A.R. [ExxonMobil Exploration Co., Houston, TX (United States)

    2003-04-01

    The prolific, oil-bearing basins of eastern Venezuela developed through an unusual confluence of Atlantic, Caribbean and Pacific plate tectonic events. Mesozoic rifling and passive margin development created ideal conditions for the deposition of world-class hydrocarbon source rocks. In the Cenozoic, transpressive, west-to-cast movement of the Caribbean plate along the northern margin of Venezuela led to the maturation of those source rocks in several extended pulses, directly attributable to regional tectonic events. The combination of these elements with well-developed structural and stratigraphic fairways resulted in remarkably efficient migration of large volumes of oil and gas, which accumulated along the flanks of thick sedimentary depocenters. At least four proven and potential hydrocarbon source rocks contribute to oil and gas accumulations. Cretaceous oil-prone, marine source rocks, and Miocene oil- and gas-prone, paralic source rocks are well documented. We used reservoired oils, seeps, organic-rich rocks, and fluid inclusions to identify probable Jurassic hypersaline-lacustrine, and Albian carbonate source rocks. Hydrocarbon maturation began during the Early Miocene in the present-day Serrania del Interior, as the Caribbean plate moved eastward relative to South America. Large volumes of hydrocarbons expelled during this period were lost due to lack of effective traps and seals. By the Middle Miocene, however, when source rocks from the more recent foredeeps began to mature, reservoir, migration pathways, and topseal were in place. Rapid, tectonically driven burial created the opportunity for unusually efficient migration and trapping of these later-expelled hydrocarbons. The generally eastward migration of broad depocenters across Venezuela was supplemented by local, tectonically induced subsidence. These subsidence patterns and later migration resulted in the mixing of hydrocarbons from different source rocks, and in a complex map pattern of variable oil quality that was further modified by biodegradation, late gas migration, water washing, and subsequent burial. The integration of plate tectonic reconstructions with the history of source rock deposition and maturation provides significant insights into the genesis, evolution, alteration, and demise of Eastern Venezuela hydrocarbon systems. We used this analysis to identify additional play potential associated with probable Jurassic and Albian hydrocarbon source rocks, often overlooked in discussions of Venezuela. The results suggest that oils associated with likely Jurassic source rocks originated in restricted, rift-controlled depressions lying at high angles to the eventual margins of the South Atlantic, and that Albian oils are likely related to carbonate deposition along these margins, post-continental break up. In terms of tectonic history, the inferred Mesozoic rift system is the eastern continuation of the Espino Graben, whose remnant structures underlie both the Serrania del Interior and the Gulf of Paria, where thick evaporate sections have been penetrated. The pattern of basin structure and associated Mesozoic deposition as depicted in the model has important implications for the Mesozoic palaeography of northern South America and Africa, Cuba and the Yucatan and associated new play potential. (author)

  10. Assessment of the Moroccan Mediterranean Coasts Contamination by Hydrocarbons (Non Aromatic Hydrocarbons, Aromatic Hydrocarbons and Linear Alkylbenzenes

    Directory of Open Access Journals (Sweden)

    Saida Bouzid

    2011-11-01

    Full Text Available In order to evaluate the contamination of the Moroccan Mediterranean coasts by persistent organic pollutants we studied hydrocarbons and linear alkylbenzenes in bivalve tissues (cockles collected seasonally from several points along the western Moroccan coasts in the Mediterranean Sea. Two fractions corresponding to non aromatic and aromatic hydrocarbons were analyzed by GC/FID and GC/MS. Non aromatic hydrocarbon concentrations vary in the range of 24.1 - 2731 ?g/g dry weight (dw while total n-alkanes vary from 2.2 to 68.2 ?g/g. Few exceptions were noted with values up to 243 ?g/g (dw, which is high compared to other Mediterranean sites. The presence of an important unresolved complex mixture (UCM indicated a significant petroleum contamination, confirmed by the identification of 17?(H, 21?(H hopanes. Biogenic contributions were also detected within the n-alkane distribution (n-C17, n-C18, n-C27, n-C29, n-C17, /Pr, n-C18, /Ph and by the presence of alkenes. C13, and C14, linear alkylbenzenes were found at concentrations of 478 - 1954 ng/g. and point to pollutant inputs from wastewaters. Polycyclic aromatic hydrocarbons were present in low concentrations below the GC detection limit. The observed seasonal and spatial variations were linked to the magnitude of inputs from marine and land-based pollutant discharges.

  11. International Trade and MIgration: A Quantitative Framework

    OpenAIRE

    Sirries, Steffen; Larch , Mario

    2014-01-01

    Goods trade and international mobility of labor are typically analyzed separately. While there is excellent research in both fields, far less is known about the interrelationships between international migration and international trade. This paper provides a first structurally estimable model of international trade with endogenous international migration choices of workers which can be used for model-based counterfactual predictions. Using bilateral trade and migration data for 33 OECD countr...

  12. Noble gas migration in auxiliary buildings

    International Nuclear Information System (INIS)

    This paper discusses the steps taken by the Engineering Department of the Arizona Nuclear Power Project (ANPP) to identify and resolve the migration of noble gases within the auxiliary buildings of Palo Verde nuclear generating station (PVNGS). As a result of HVAC design evaluation, tracer gas testing, and computer model analysis, areas of the buildings with potential for noble gas migration were identified. On the basis of these identifications, retrofit work is proceeding to reduce or eliminate noble gas migration

  13. Green Light for Nocturnally Migrating Birds

    OpenAIRE

    Wernand, Marcel R.; Donners, Maurice A. H.; Han de Vries; Ens, Bruno J.; Hanneke Poot; Marquenie, Joop M.

    2008-01-01

    The nighttime sky is increasingly illuminated by artificial light sources. Although this ecological light pollution is damaging ecosystems throughout the world, the topic has received relatively little attention. Many nocturnally migrating birds die or lose a large amount of their energy reserves during migration as a result of encountering artificial light sources. This happens, for instance, in the North Sea, where large numbers of nocturnally migrating birds are attracted to the many offsh...

  14. An Econophysics Model for the Migration Phenomena

    CERN Document Server

    Gheorghiu, Anca

    2012-01-01

    Knowing and modelling the migration phenomena and especially the social and economic consequences have a theoretical and practical importance, being related to their consequences for development, economic progress (or as appropriate, regression), environmental influences etc. One of the causes of migration, especially of the interregional and why not intercontinental, is that resources are unevenly distributed, and from the human perspective there are differences in culture, education, mentality, collective aspirations etc. This study proposes a new econophysics model for the migration phenomena.

  15. Volatile organic migration from hazardous waste sites

    International Nuclear Information System (INIS)

    Volatile organics in hazardous waste piles and organic liquid spills generate gaseous vapors that can have a significant negative environmental impact. Present methods for calculating organic vapor migration through soils neglect many important phenomena that influence the magnitude of the migration rate. This paper presents a methodology for predicting organic vapor migration that involves two-phase flow, absorption in soil moisture, and transport by diffusive and advective mechanisms

  16. New directions for migration policy in Europe.

    OpenAIRE

    Laczko, Frank

    2002-01-01

    There is a growing debate about the future direction of migration policy in Europe. After nearly 30 years of pursuing restrictive immigration and asylum policies, many European Union (EU) governments are beginning to re-assess their migration policies and to call for a new approach. For the first time in many years, several EU governments have begun to talk again about the benefits of labour migration and, even more significantly, have even begun to take action to recruit more migrants, espec...

  17. Egypt: Socio-political dimensions of migration

    OpenAIRE

    SIKA, Nadine

    2011-01-01

    This study argues that the Egyptian government both prior to and after the January 25th revolution encourages the migration of Egyptians abroad, in order to lower unemployment, and to increase remittances. Bilateral agreements on temporary and irregular migration have been signed with different governments, of which the Egyptian-Italian agreement on migration remains the most important. Moreover, the Egyptian government applies stricter rules concerning foreign workers in Egypt. Finally, the ...

  18. Service Migration Protocol for NFC Links

    OpenAIRE

    Nickelsen A.; Martin M; Schwefel H.-P.

    2010-01-01

    In future ubiquitous communication environments, users expect to move freely while continuously interacting with the available applications through a variety of devices. Interactive applications will therefore need to support migration, which means to follow users and adapt to the changing context of use while preserving state. This paper focuses on the scenario of migration between two devices in which the actual migration procedure is executed over near-field communication (NFC) ad-hoc link...

  19. Migration and remittances in Macedonia: A review

    OpenAIRE

    Dietz, Barabara

    2010-01-01

    This paper explores migration movements and remittances patterns in Macedonia since independence and studies the migration policy challenges Macedonia will be likely to face after its entry into the EU. Concerning recent migration movements, considerable outflows from Macedonia are found as well as indications for a serious brain drain. Remittances to Macedonia - which are quite big - seem to constitute a relevant support for a number of households and can be expected to diminish the incidenc...

  20. Guidance of Cell Migration by Substrate Dimension

    OpenAIRE

    Chang, Stephanie s; Guo, Wei-hui; Kim, Youngeun; Wang, Yu-li

    2013-01-01

    There is increasing evidence to suggest that physical parameters, including substrate rigidity, topography, and cell geometry, play an important role in cell migration. As there are significant differences in cell behavior when cultured in 1D, 2D, or 3D environments, we hypothesize that migrating cells are also able to sense the dimension of the environment as a guidance cue. NIH 3T3 fibroblasts were cultured on micropatterned substrates where the path of migration alternates between 1D lines...

  1. Protoplanetary migration in turbulent isothermal disks

    OpenAIRE

    Baruteau, C.; Lin, D.N.C.

    2009-01-01

    In order to reproduce the statistical properties of the observed exoplanets, population synthesis models have shown that the migration of protoplanets should be significantly slowed down, and that processes stalling migration should be at work. Much current theoretical efforts have thus been dedicated to find physical effects that slow down, halt or even reverse migration. Many of these studies rely on the horseshoe drag, whose long term-evolution (saturated or not) is intim...

  2. Object migration in federated database systems

    OpenAIRE

    Radeke, Elke; Scholl, Marc H.

    1994-01-01

    Existing federated database systems (FDBS) provide uniform access to multiple heterogeneous DBS, but do not enable objects to move across the DBS while retaining global identity. To fulfill this requirement of industrial users, we incorporate into FDBS a flexible object migration mechanism to move or duplicate objects from one component database system to another. We present different capabilities for "what" and "how" to migrate and consider the migration of both single objects and whole o...

  3. International scientific migrations today : new perspectives

    OpenAIRE

    Narvaez-Berthelemot, N.; Rosas, A. M.

    1996-01-01

    La migration des scientifiques des pays en développement vers les pays développés a été l'objet de diverses études. La migration, mais dans la direction opposée, apparaît comme une alternative pour la consolidation du potentiel scientifique d'un pays. Dans la présente étude nous nous proposons d'analyser cet aspect de la migration, en prenant comme base les données du Système national de chercheurs (Sistema Nacional de Investigatores, SIN), du Mexique. Nous analyserons la participation des sc...

  4. Deep gas in the Barbados accretionary prism: Sources, migration, detection: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Speed, R.C.

    1987-06-01

    The project objectives are: (1) to detect the existence on Barbados of gas derived from underthrust or underplated sediments at the prism base (now at 20 to 25 km in depth); (2) to understand the conditions and processes of organic maturation within and below the accretionary prism and the evolution of migration plants and reservoirs for gas within this progressively deforming mass; (3) to consider further strategies and methodologies by which gases generated at deep and shallow depths may be discriminated; (4) to study processes of accretion and structure generated in an active intra-oceanic subduction zone (Lesser Antilles) with large influx of terrigenous sediments; and (5) to provide a modern analog for the structural and hydrocarbon evolution of ancient Cordilleran accretionary complexes that incorporate an abundance of terrigenous sediment. Contents of this report include: forearcs and hydrocarbons; forearcs in global context, Lesser Antilles forearc; geologic evolution of Barbados; organic and hydrocarbon contents; thermal; deformation and structures; fluid emission; applications to ancient US prisms; and conclusions.

  5. Problems in Catalytic Oxidation of Hydrocarbons and Detailed Simulation of Combustion Processes

    Science.gov (United States)

    Xin, Yuxuan

    This dissertation research consists of two parts, with Part I on the kinetics of catalytic oxidation of hydrocarbons and Part II on aspects on the detailed simulation of combustion processes. In Part I, the catalytic oxidation of C1--C3 hydrocarbons, namely methane, ethane, propane and ethylene, was investigated for lean hydrocarbon-air mixtures over an unsupported Pd-based catalyst, from 600 to 800 K and under atmospheric pressure. In Chapter 2, the experimental facility of wire microcalorimetry and simulation configuration were described in details. In Chapter 3 and 4, the oxidation rate of C1--C 3 hydrocarbons is demonstrated to be determined by the dissociative adsorption of hydrocarbons. A detailed surface kinetics model is proposed with deriving the rate coefficient of hydrocarbon dissociative adsorption from the wire microcalorimetry data. In Part II, four fundamental studies were conducted through detailed combustion simulations. In Chapter 5, self-accelerating hydrogen-air flames are studied via two-dimensional detailed numerical simulation (DNS). The increase in the global flame velocity is shown to be caused by the increase of flame surface area, and the fractal structure of the flame front is demonstrated by the box-counting method. In Chapter 6, skeletal reaction models for butane combustion are derived by using directed relation graph (DRG) and DRG-aided sensitivity analysis (DRGASA), and uncertainty minimization by polynomial chaos expansion (MUM-PCE) mothodes. The dependence of model uncertainty is subjected to the completeness of the model. In Chapter 7, a systematic strategy is proposed to reduce the cost of the multicomponent diffusion model by accurately accounting for the species whose diffusivity is important to the global responses of the combustion systems, and approximating those of less importance by the mixture-averaged model. The reduced model is validated in an n-heptane mechanism with 88 species. In Chapter 8, the influence of Soret diffusion on the n-heptane/air flames is investigated numerically. In the unstretched flames, Soret diffusion primarily affects the chemical kinetics embedded in the flame structure and the net effect is small; while in the stretched flames, its impact is mainly through those of n-heptane and the secondary fuel, H2, in modifying the flame temperature, with substantial effects.

  6. Migration and Development Research Scoping Study

    OpenAIRE

    Lacroix, Thomas

    2008-01-01

    This consultancy assess es current migration research to determine the key factors which need to be considered in order to better understand the drivers of migration for poor people, as well as the social and economic costs and benefits of migration. The purpose of the consultancy is to carry out a scoping ex ercise that will inform the design of a new research programme on migration to be funded under the DFID Research Strategy. E mpirical work has highlighted the development potential of mi...

  7. The migration of uranium through sandstone

    International Nuclear Information System (INIS)

    Three column experiments are described in which the migration of uranium through Clashach Sandstone was studied. A priori predictions of uranium migration in the experiments were made using an equilibrium chemical transport model. The experimental results showed that, even under oxidising conditions, the migration of uranium is strongly retarded owing to the affinity of uranium for mineral surfaces. For the relatively simple chemical system investigated, the chemical transport model was successful in predicting the migration of uranium and its distribution along the column. (author)

  8. Neuronal migration disorders. Radiological and clinical aspects

    International Nuclear Information System (INIS)

    Neuronal migration disorders can cause congenital cerebral malformations during the third and fourth months of gestation. They are usually classified as agyria, pachygyria, schizencephaly, polymicrogyria and heterotopic gray matter. The best diagnostic tool for detecting neuronal migration disorders is magnetic resonance imaging (MRI). Frequently, the migration disorders are associated with epilepsy, and patients with these symptoms should always be investigated by cerebral MRI. In this article the authors discuss radiologic and clinical aspects in the case of six persons with different categories of migration disorder. 19 refs., 12 figs., 2 tabs

  9. Secondary Aortoduodenal Fistula

    Directory of Open Access Journals (Sweden)

    Meng-Wei Chang

    2002-09-01

    Full Text Available Secondary aortoenteric fistula (SAF is now recognized as an uncommon but exceedinglyimportant complication of abdominal aortic reconstruction. The complication oftenoccurs months to years after the original surgery. The main clinical manifestation of the diseaseis always upper gastrointestinal bleeding. Treatment of the disease is early surgicalintervention. The mortality is high if no prompt operation. We present a case of secondaryaortoduodenal fistula (SADF found 20 days after aortic reconstructive surgery, with theclinical presentation of upper gastrointestinal bleeding. Even immediate exploratory laparotomywas performed, the patient died 48 hrs after the surgical management. Because of theincreasing number of elective aortic aneurysm repairs in the aging population, it is likelythat more patients with SAF will present to the clinical physicians in the future. So, a highindex of suspicion is necessary for prompt diagnosis and treatment of this actually lifethreateningevent.

  10. Secondary standards dosimetry laboratories

    International Nuclear Information System (INIS)

    The Secondary Standards Dosimetry Laboratory (SSDL) is part of an international network of dosimetry laboratories established by the IAEA and WHO. The network services maintain the consistency and accuracy of the therapeutic dose by exercising a national and international intercomparison program as well as providing calibration services to the end users, mainly radiotherapy departments in hospitals. The SSDL's are designated by national laboratories (such as Primary Standards Dosimetry Laboratories, PSDL's) to provide national and international absorbed dose traceability for users in that country. The advantage of the SSDL is that the absorbed dose measurements are consistent among the stakeholder countries.The Physics and Safety divisions have recently re-established an SSDL at ANSTO. The SSDL utilises a collimated cobalt-60 source of activity 170 TBq and dose rate of SmGy/sec at 1 metre (within ±2%), and provides a service to calibrate therapy level thimble ionisation chambers and electrometers

  11. New secondary energy systems

    International Nuclear Information System (INIS)

    As an introduction, the FRG's energy industry situation is described, secondary energy systems to be taken into consideration are classified, and appropriate market requirements are analyzed. Dealt with is district heating, i.e. the direct transport of heat by means of circulating media, and long-distance energy, i.e. the long-distance energy transport by means of chemical conversion in closed- or open-cycle systems. In closed-cycle systems heat is transported in the form of chemical latent energy. In contrast to this, chemical energy is transported in open-cycle systems in the form of fuel gases produced by coal gasification or by thermochemical water splitting. (GG)

  12. Co-processing of standard gas oil and biocrude oil to hydrocarbon fuels

    International Nuclear Information System (INIS)

    The major obstacle in thermochemical biomass conversion to hydrocarbon fuels using pyrolysis has been the high oxygen content and the poor stability of the product oils, which cause them to solidify during secondary processing. We have developed a fractional catalytic pyrolysis process to convert biomass feedstocks into a product termed “biocrude oils” (stable biomass pyrolysis oils) which are distinct from unstable conventional pyrolysis oils. The biocrude oils are stable, low viscosity liquids that are storable at ambient conditions without any significant increases in viscosity; distillable at both atmospheric pressure and under vacuum without char or solid formation. About 15 wt% biocrude oils containing 20–25% oxygen were blended with 85 wt% standard gas oil and co-cracked in an Advanced Catalyst Evaluation (ACE™) unit using fluid catalytic cracking (FCC) catalysts to produce hydrocarbon fuels that contain negligible amount of oxygen. For the same conversion of 70% for both the standard gas oil and the biocrude oil/gas oil blends, the product gasoline yield was 44 wt%, light cycle oil (LCO) 17 wt%, heavy cycle oil (HCO) 13 wt%, and liquefied petroleum gas (LPG) 16 wt%. However, the coke yield for the standard gas oil was 7.06 wt% compared to 6.64–6.81 wt% for the blends. There appeared to be hydrogen transfer from the cracking of the standard gas oil to the biocrude oil which subsequently eliminated the oxygen in the fuel without external hydrogen addition. We have demonstrated for the first time that biomass pyrolysis oils can be successfully converted into hydrocarbons without hydrogenation pretreatment. -- Highlights: ? The co-processed product had less than 1% oxygen content and contained biocarbons determined by 14C analysis. ? The co-processing did not affect the yields of gasoline, LCO, and HCO. ? First demonstration of direct conversion of pyrolysis oils into drop-in hydrocarbon fuels.

  13. GMT adaptive secondary design

    Science.gov (United States)

    Biasi, R.; Veronese, D.; Andrighettoni, M.; Angerer, G.; Gallieni, D.; Mantegazza, M.; Tintori, M.; Lazzarini, P.; Manetti, M.; Johns, M. W.; Hinz, P. M.; Kern, J.

    2010-07-01

    The GMT adaptive secondary mirror (ASM) is based on a "segmented" concept following the primary segment layout: seven 1.05m diameter circular, independent adaptive mirrors are fed by the primaries and focus to the main telescope focal stations. The adaptive unit's design is based on the consolidated thin mirror, contactless technology already employed in several units (MMT, LBT, Magellan, VLT and one of the proposed E-ELT M4 designs), but nevertheless the mirror's topology reveals several design challenges. In particular, the off-axis units are strongly aspheric and therefore they require aspheric shaping of both thin mirror surfaces and of the thick reference body. The strong tilt of the off-axis units forced us to consider a peculiar fine positioning hexapod design, maximizing its stiffness and also implementing a special design of the last three rings of actuators to remain within the prescribed obstruction. From the control point of view, the actuator density of the adaptive mirrors is remarkably lower than in all previous units: 672 actuators with 36mm spacing compared to 30mm typical separation adopted so far. This choice is validated by static and dynamic performance computation though a sophisticated numerical simulator based on a full state space model incorporating mechanics, control and fluid dynamics. The control system fulfills the dimensional constraints of the unit. The design has completed the feasibility phase, including the cost estimate. The choice of making the GMT adaptive secondary mirrors similar to the already existing ones strongly reduces the implementation risks and allows shortening the remaining design path.

  14. Reflection tomography from pre-stack migrated images; Tomographie de reflexion a partir des images migrees avant addition

    Energy Technology Data Exchange (ETDEWEB)

    Adler, F.

    1996-10-29

    The application of reflection tomography to data from complex geological structures is very interesting in the hydrocarbons exploration. Indeed, it contributes to localize the hydrocarbons potential traps. The used reflection tomography method is faced with two major difficulties. Travel time picking is difficult or impossible in seismic time sections. The processing of multiple arrival travel times needs an adequate formulation of reflection tomography. In order to solve the first problem, we adopt the approach of the SMART (Sequential Migration Aided Reflection Tomography) method which is an original method for the implementation of migration velocity analysis. The velocity model is automatically calculated by reflection tomography. The kinematic data set for reflection tomography is constructed from pre-stack depth-migrated images that are interpreted in the chosen migration configuration. For the implementation of the SMART method in the common-offset domain, we propose an original formulation of reflection tomography that takes multiple arrival travel times, which are calculated from common-offset migrated images, into account. In this new formulation, we look for a model such that a modelling, which consists in shooting in this model from the source locations with some ray parameters at the source, matches some emergence conditions: for each offset, the rays emerge at the receiver locations (given by the offset) with the same travel times and the same travel time slopes as observed in the associated common-offset section. These conditions constitute the kinematic data set for tomographic inversion. The common-offset travel time slope is the difference between the ray parameter at the receiver and the ray parameter at the source. Therefore, the ray parameter at the source is an unknown and has to be determined together with the model parameters during inversion. (author)

  15. Chapter V: Secondary landscape structure

    International Nuclear Information System (INIS)

    This chapter deals with the secondary landscape structure of the Slovak Republic. It consists of next subchapters: (1) Land use pattern; (2) Special landscape structures; (3) Real vegetation. The secondary landscape structure consists of the elements influenced by man, created or recreated. They represent material elements with a particular spatial delimitation in the landscape. Vegetation, above all forest vegetation, is the indispensable part of the secondary landscape structure. Special space was given to the historical landscape structure

  16. Syndication and Secondary Loan Sales

    OpenAIRE

    Paolo Colla; Filippo Ippolito

    2011-01-01

    Secondary loan sales give originating banks the opportunity to diversify part of their credit risk by selling loans to other market participants. However, as originating banks are less exposed to risk after secondary loan sales, their incentives to monitor borrowers diminish. Secondary loan sales therefore involve a trade-off between diversification benefits and sub-optimal monitoring. We explore this trade-off within a theoretical model. The results show that in equilibrium loans trade at a ...

  17. Secondary maxima in ozone profiles

    OpenAIRE

    Lemoine, R.

    2004-01-01

    Ozone profiles from balloon soundings as well as SAGE II ozone profiles were used to detect anomalous large ozone concentrations of ozone in the lower stratosphere. These secondary ozone maxima are found to be the result of differential advection of ozone-poor and ozone-rich air associated with Rossby wave breaking events. The frequency and intensity of secondary ozone maxima and their geographical distribution is presented. The occurrence and amplitude of ozone secondary maxima is related to...

  18. Managing migration in the IOM’s World migration report 2008

    OpenAIRE

    Campillo Carrete, B.; Gasper, D.R.

    2010-01-01

    The 2008 World Migration Report from the International Organization for Migration is an enormous document that reflects efforts led by business sectors and some sections of governments in rich countries to move away from policy agendas overwhelmingly focused on restriction of international migration, towards a somewhat more open global economic order, and to build acceptance of substantial in-migration to match market demand. This paper illustrates use of methods of discours...

  19. Remedial technology selection for hydrocarbon contaminated soils

    International Nuclear Information System (INIS)

    Environmental project managers for major industrial companies must make decisions in a dynamic world. Faced with regulatory changes, legal influences, tight expense controls, and evolving technology, project managers work to solve environmental problems at their company's owned or operated properties. One large subset of environmental problems involves subsurface hydrocarbon contamination in the unsaturated zone. The objective of this paper is to provide a decision analysis framework for making remedial technology selections for hydrocarbon contaminated soils. The paper outlines the decision-making problems, details the critical components of the decision, and formats the processing of information for the decision-making. The paper will serve as a standard to allow the application of decision analysis to the complex unsaturated zone remediation issues facing industry today

  20. Monitoring of vapor phase polycyclic aromatic hydrocarbons

    Science.gov (United States)

    Vo-Dinh, Tuan; Hajaligol, Mohammad R.

    2004-06-01

    An apparatus for monitoring vapor phase polycyclic aromatic hydrocarbons in a high-temperature environment has an excitation source producing electromagnetic radiation, an optical path having an optical probe optically communicating the electromagnetic radiation received at a proximal end to a distal end, a spectrometer or polychromator, a detector, and a positioner coupled to the first optical path. The positioner can slidably move the distal end of the optical probe to maintain the distal end position with respect to an area of a material undergoing combustion. The emitted wavelength can be directed to a detector in a single optical probe 180.degree. backscattered configuration, in a dual optical probe 180.degree. backscattered configuration or in a dual optical probe 90.degree. side scattered configuration. The apparatus can be used to monitor an emitted wavelength of energy from a polycyclic aromatic hydrocarbon as it fluoresces in a high temperature environment.

  1. Geological computer file applications in hydrocarbon exploration

    Energy Technology Data Exchange (ETDEWEB)

    Badawi, A.F.Z.

    1976-01-01

    The existence of computer-compatible magnetic storage media with capacities of millions and even billions of bits provides the capability of automatically organizing voluminous exploration data into well-ordered computer files. An actual case is presented of the application of a geological information system to hydrocarbon exploration. The purpose of the study was to highlight prospective areas in a region with known production from basal Cretaceous hydrocarbon accumulations. It was felt that great potential for further discoveries existed. A data-processing solution to the problem suggested itself. If the gross effect of post-depositional influences could be determined from a trend analysis, it could be removed from the data. Mapping of the resulting residual data component should enhance the more subtle sub-Cretaceous erosional surface that influenced subsequent Early Cretaceous clastic deposition.

  2. Macroporous polymer foams by hydrocarbon templating

    Science.gov (United States)

    Shastri, Venkatram Prasad; Martin, Ivan; Langer, Robert

    2000-01-01

    Porous polymeric media (polymer foams) are utilized in a wide range of applications, such as thermal and mechanical insulators, solid supports for catalysis, and medical devices. A process for the production of polymer foams has been developed. This process, which is applicable to a wide range of polymers, uses a hydrocarbon particulate phase as a template for the precipitation of the polymer phase and subsequent pore formation. The use of a hydrocarbon template allows for enhanced control over pore structure, porosity, and other structural and bulk characteristics of the polymer foam. Polymer foams with densities as low as 120 mg/cc, porosity as high as 87%, and high surface areas (20 m2/g) have been produced. Foams of poly(l-lactic acid), a biodegradable polymer, produced by this process have been used to engineer a variety of different structures, including tissues with complex geometries such as in the likeness of a human nose. PMID:10696111

  3. HYDROCARBONS FROM PLANTS: ANALYTICAL METHODS AND OBSERVATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Calvin, Melvin

    1980-05-01

    We have suggested that certain plants rich in hydrocarbon-like materials might be cultivated for renewable photosynthetic products. Two species were selected for experimental plantations: Euphorbia lathyris, an annual from seed and Euphorbia tirucalli, a perennial from cuttings, The yield from each species is over 10 barrels of oil/acre/year without genetic or agronomic improvement. In addition to plants, there are trees, such as species of Copaifera in Brazil and other tropical areas, which produce a diesel-like oil upon tapping. Each tree produces approximately 40 liters of hydrocarbon per year, and this material can be used directly by a diesel-powered car. Further efforts to develop plants as alternate energy sources are underway, as well as a continuing search for additional plant species throughout the world which have a similar capability.

  4. CHARACTERISTICS OF HYDROCARBON EXPLOITATION IN ARCTIC CIRCLE

    Directory of Open Access Journals (Sweden)

    VANJA LEŽ

    2013-12-01

    Full Text Available The existence of large quantities of hydrocarbons is supposed within the Arctic Circle. Assumed quantities are 25% of the total undiscovered hydrocarbon reserves on Earth, mostly natural gas. Over 500 major and minor gas accumulations within the Arctic Circle were discovered so far, but apart from Snohvit gas field, there is no commercial exploitation of natural gas from these fields. Arctic gas projects are complicated, technically hard to accomplish, and pose a great threat to the return of investment, safety of people and equipment and for the ecosystem. Russia is a country that is closest to the realization of the Arctic gas projects that are based on the giant gas fields. The most extreme weather conditions in the seas around Greenland are the reason why this Arctic region is the least explored and furthest from the realization of any gas project.

  5. HYDROCARBON-DEGRADING BACTERIA AND SURFACTANT ACTIVITY

    Energy Technology Data Exchange (ETDEWEB)

    Brigmon, R; Topher Berry, T; Grazyna A. Plaza, G; jacek Wypych, j

    2006-08-15

    Fate of benzene ethylbenzene toluene xylenes (BTEX) compounds through biodegradation was investigated using two different bacteria, Ralstonia picketti (BP-20) and Alcaligenes piechaudii (CZOR L-1B). These bacteria were isolated from extremely polluted petroleum hydrocarbon contaminated soils. PCR and Fatty Acid Methyl Ester (FAME) were used to identify the isolates. Biodegradation was measured using each organism individually and in combination. Both bacteria were shown to degrade each of the BTEX compounds. Alcaligenes piechaudii biodegraded BTEXs more efficiently while mixed with BP-20 and individually. Biosurfactant production was observed by culture techniques. In addition 3-hydroxy fatty acids, important in biosurfactant production, was observed by FAME analysis. In the all experiments toluene and m+p- xylenes were better growth substrates for both bacteria than the other BTEX compounds. In addition, the test results indicate that the bacteria could contribute to bioremediation of aromatic hydrocarbons (BTEX) pollution increase biodegradation through the action by biosurfactants.

  6. Electrochemical Routes towards Sustainable Hydrocarbon Fuels

    DEFF Research Database (Denmark)

    Mogensen, Mogens Bjerg Technical University of Denmark,

    2012-01-01

    The potential of renewable energy and possible solution to the intermittency problem of renewable energy sources like sun and wind are explained. The densest storage of energy is in the form of hydrocarbons. The most suitable method of conversion and storage within a foreseeable future is electrolysis followed by conversion into synthetic hydrocarbons, alcohols or ethers. Several types of electrolysers exist. The various types are listed together with a short description of principle and status. It is argued that electrolysis will at least become part of large sustainable energy systems in the future. In spite of this, it is important to research and develop as many viable sustainable energy technologies as economical possible. © 2012 ECS - The Electrochemical Society  

  7. GDR Hycar work on the origin, fate and consequences of hydrocarbons in marine sediments

    International Nuclear Information System (INIS)

    This article reviews the experimental results achieved by GDR Hycar concerning the degradation of petroleum hydrocarbons in marine deposits. The authors describe the experimental strategy that has been set up, in situ, in the Fos Gulf. 96 sediment pancakes, one cm thick and contaminated with a known quantity of petroleum have been installed on the sea bed, 5 meters below the water line. The aim was to follow the decay and migration of oil in deeper sediment layers underneath the pancakes. The experiment shows: -) a good decontamination of the pancake after 3 years, -) the presence of oil decay products in the 2-4 cm deep sediment layer, -) the presence of low-degraded oil (coming from the experiment and from previous contaminations of the site) in the 6 cm deep layer. The last result shows that the alteration process of oil slows down as it takes place deeper in the sediment layers. (A.C.)

  8. Migration for Labor, Migration for Love: Marriage and Family Formation across Borders.

    Science.gov (United States)

    Sinke, Suzanne

    1999-01-01

    Addresses how marriage and migration interacted using migration to the United States as an example; the key variables determining this relationship were demographics, legal policies, cultural perceptions, and information and technology. Maintains that the influence of an international marriage market affected the migration decisions of women who…

  9. Gravity observations for hydrocarbon reservoir monitoring:

    OpenAIRE

    Glegola, M. A.

    2013-01-01

    In this thesis the added value of gravity observations for hydrocarbon reservoir monitoring and characterization is investigated. Reservoir processes and reservoir types most suitable for gravimetric monitoring are identified. Major noise sources affecting time-lapse gravimetry are analyzed. The added value of gravity data for reservoir monitoring and characterization is analyzed within closed-loop reservoir management concept. Synthetic 2D and 3D numerical experiments are performed where va...

  10. National Gas Survey. Synthesized gaseous hydrocarbon fuels

    Energy Technology Data Exchange (ETDEWEB)

    None

    1978-06-01

    The supply-Technical Advisory Task Force-Synthesized Gaseous Hydrocarbon Fuels considered coal, hydrocarbon liquids, oil shales, tar sands, and bioconvertible materials as potential feedstocks for gaseous fuels. Current status of process technology for each feedstock was reviewed, economic evaluations including sensitivity analysis were made, and constraints for establishment of a synthesized gaseous hydrocarbon fuels industry considered. Process technology is presently available to manufacture gaseous hydrocarbon fuels from each of the feedstocks. In 1975 there were eleven liquid feedstock SNG plants in the United States having a capacity of 1.1 billion SCFD. There can be no contribution of SNG before 1982 from plants using feedstocks other than liquids because there are no plants in operation or under construction as of 1977. Costs for SNG are higher than current regulated prices for U.S. natural gas. Because of large reserves, coal is a prime feedstock candidate although there are major constraints in the area of coal leases, mining and water permits, and others. Commercial technology is available and several new gasification processes are under development. Oil shale is also a feedstock in large supply and commercial process technology is available. There are siting and permit constraints, and water availability may limit the ultimate size of an oil shale processing industry. Under projected conditions, bioconvertible materials are not expected to support the production of large quantities of pipeline quality gas during the next decade. Production of low or medium Btu gas from municipal solid wastes can be expected to be developed in urban areas in conjunction with savings in disposal costs. In the economic evaluations presented, the most significant factor for liquid feedstock plants is the anticipated cost of feedstock and fuel. The economic viability of plants using other feedstocks is primarily dependent upon capital requirements.

  11. Methane conversion to hydrocarbons by double discharge

    Directory of Open Access Journals (Sweden)

    A. M. Ghorbanzadeh

    2004-12-01

    Full Text Available   Methane conversion to higher hydrocarbons by pulsed glow discharge at the atmospheric pressure was investigated. The energy efficiency up to 10 % was obtained which is higher than any value ever published for nonequilibrium plasma conversion of pure methame. This method has a potential for development and it is expected that the energy efficiency will be improved further if the plasma parameters are optimized.

  12. SULFUR COMPOUNDS IN PETROLEUM HYDROCARBON STREAMS

    OpenAIRE

    Antoaneta Pavlova; Pavlina Ivanova; Teodora Dimova

    2012-01-01

    Determination of concentrations of sulfur compounds in different petroleum samples is a true analytical challenge. Only analytical procedures based on gas chromatography can meet the sensitivity and accuracy requirements dictated by up-to-date petroleum industry.The objective of this work is to develop the method for the quantifying of sulfur compounds in petroleum hydrocarbon streams. The optimum parameters for the GC-SCD method are found in order to determine of sulfur compounds in petroleu...

  13. HYDROCARBON FORMATION ON POLYMER-SUPPORTED COBALT

    Energy Technology Data Exchange (ETDEWEB)

    Benner, Linda S.; Perkins, Patrick; Vollhardt, K.Peter C.

    1980-10-01

    In this report we detail the synthesis catalytic chemistry of polystyrene supported {eta}{sup 5} ~cyclopentadienyl- dicarbonyl cobalt, CpCo(CO){sub 2}. This material is active in the hydrogenation of CO to saturated linear hydrocarbons and appears to retain its "homogeneous", mononuclear character during the course of its catalysis, During ·the course of our work 18% and 20% crosslinked analogs of polystyrene supported CpCo(CO){sub 2} were shown to exhibit limited catalytic activity and no CO activation.

  14. Hydrochloric acid recycling from chlorinated hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Sowieja, D. [Sulzer Escher Wyss GmbH, Ravensburg (Germany); Schaub, M. [Sulzer Chemtech Ltd., Winterthur (Switzerland)

    1993-12-31

    Chlorinated hydrocarbons present a major ecological hazard since most of them are only poorly biodegradable. Incineration is an economical process for their destruction, however the usually recovered sodium or calcium chlorides do not present a value and their disposal may even be very costly. Recovery of hydrochloric acid may therefore present an economical solution, mainly were large quantities of highly chlorinated compounds can be processed (author) 6 refs., 4 figs., 1 tab.

  15. Biodegradation of polycyclic hydrocarbons by Phanerochaete chrysosporium.

    OpenAIRE

    Bumpus, J A

    1989-01-01

    The ability of the white rot fungus Phanerochaete chrysosporium to degrade polycyclic aromatic hydrocarbons (PAHs) that are present in anthracene oil (a distillation product obtained from coal tar) was demonstrated. Analysis by capillary gas chromatography and high-performance liquid chromatography showed that at least 22 PAHs, including all of the most abundant PAH components present in anthracene oil, underwent 70 to 100% disappearance during 27 days of incubation with nutrient nitrogen-lim...

  16. Growth of fungi on volatile aromatic hydrocarbons

    OpenAIRE

    Prenafeta Boldú, F.X.

    2002-01-01

    The present study aimed the better understanding of the catabolism of monoaromatic hydrocarbons by fungi. This knowledge can be used to enhance the biodegradation of BTEX pollutants. Fungi with the capacity of using toluene as the sole source of carbon and energy were isolated by enriching environmental polluted soil and groundwater samples in solid state-like batches, air biofilters, and liquid cultures. Incubation conditions in the latter combined acidic pH and low water activity. The isola...

  17. Polycyclic Aromatic Hydrocarbons Degradation Techniques: A Review

    OpenAIRE

    Luke N. Ukiwe; Ubaezue U. Egereonu; Pascal C. Njoku; Christopher I. A. Nwoko; Jude I. Allinor

    2013-01-01

    The demand for processed petroleum products and agricultural produce has exposed our environment to polycyclic aromatic hydrocarbons (PAHs) contamination. PAHs stick to solid sediments and are ubiquitous including soil, water and air. Their presence in these media creates problems because consuming products obtained from these sources could be deleterious to human health since several of these compounds (benz(a)anthracene, benzo(a)pyrene, chrysene etc) have been implicated in causing tumors i...

  18. From pyrene to large polycyclic aromatic hydrocarbons

    OpenAIRE

    Fogel, Yulia

    2007-01-01

    Studies of polycyclic aromatic hydrocarbons have shown that the overall size, periphery, and functionalization of PAHs are crucial parameters which significantly alter their electronic structure and chemical reactivity. Therefore, the major direction of this thesis is the synthesis and characterization of extended PAHs: (i) with different functional groups improving their processability, (ii) with different periphery changing their chemical reactivity, (iii) with inclusions of different meta...

  19. Kinetic model for methanol conversion to hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Mihail, R.; Straja, S.; Maria, G.; Musca, G.; Pop, G.

    1983-01-01

    A detailed kinetic model has been developed for methanol conversion to hydrocarbons over zeolites. The dimethylether at equilibrium with methanol, generates carbene; it attacks the oxygenates giving light olefins, and the latter forming higher olefins. The olefins, through carbenium ions, form aromatics and paraffins. The kinetic parameters, identified by nonlinear optimization techniques, and the model predictions, agree quite well with the experimental and literature available data. 5 figures, 5 tables.

  20. Hydrocarbon content of geopressured brines. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Osif, T.L.

    1985-08-01

    Design Well data (bottomhole pressure minus wellhead pressure, GWR, and hydrocarbon composition) is presented as a function of producing conditions. These are examined in conjunction with the following models to attempt to deduce the reservoir brine saturation level: (1) reservoir contains gas dispersed in the pores and the gas saturation is greater than critical; (2) reservoir brine is gas-saturated; (3) bubble point below hydrostatic pressure; and (4) bubble point between hydrostatic pressure and reservoir pressure. 24 figs., 10 tabs. (ACR)

  1. Aliphatic hydrocarbon and polycyclic aromatic hydrocarbon geochemistry of twelve major rivers in the Northwest Territories

    International Nuclear Information System (INIS)

    Suspended sediment and water samples collected from twelve major rivers in the Northwest Territories were analyzed for aliphatic hydrocarbons and polycyclic aromatic hydrocarbons (PAHs) to assess the sources and transport of hydrocarbons entering the Arctic Ocean. Three stations on the Mackenzie River and one station near the mouth of eleven other northern rivers were selected for sampling. Samples were collected on the Mackenzie River on four occasions to characterize spring, summer and fall flow conditions and once on the remaining eleven rivers during high flow conditions. The Mackenzie River is distinctively different then the other eleven rivers. Naturally occurring hydrocarbons predominate in the river. These hydrocarbons include biogenic alkanes, diagenic PAHs, petrogenic alkanes, and PAHs from oil seeps and/or bitumens. Anthropogenic inputs of PAHs are low as indicated by low concentrations of combustion PAHs. Alkyl PAH distributions indicate that a significant component of the lower molecular weight PAH fraction is petrogenic. The majority of the high molecular weight PAHs, together with the petrogenic PAHs have a principal source in the Mackenzie River

  2. Are Aromatic Hydrocarbons Generated from the Atmospheric Oxidation of Biogenic Hydrocarbons?

    Science.gov (United States)

    Gratien, A.; Johnson, S. N.; Ezell, M. J.; Wingen, L. M.; Perraud, V. M.; Dawson, M.; Bennett, R.; Finlayson-Pitts, B. J.

    2010-12-01

    Biogenic volatile organic compounds (BVOCs) are estimated to account for approximately 90% of total hydrocarbon emissions. When released into the troposphere, these BVOC undergo chemical oxidation, e.g. by hydroxyl radicals (OH) and ozone (O3) during daytime, and by nitrate radicals (NO3) and ozone at night. Anthropogenic sources release into the troposphere a wide range of volatile organic compounds (VOC), also including aromatic hydrocarbons. Their major source is believed to be the combustion and the evaporation of the fuels. One question is while there are others sources of aromatics in air. For example, an aromatic hydrocarbon, p-cymene, was recently reported in air above a forest canopy that had significant emissions of terpenes (isoprene, ?-pinene, ?-pinene, limonene…), and its concentration increased as a function of altitude, suggesting its possible formation in the atmosphere. The goal of the present study was to determine whether p-cymene can be generated from reactions of biogenic hydrocarbons in air. The oxidations of isoprene, ?-pinene, ?-pinene and limonene by O3, NO3 and OH have been studied at 1 atm air under dry conditions, at high relative humidity (70% RH), or with deliquesced sodium bisulfate (acid source) on the walls of a Teflon reaction chamber. A search for the generation of aromatic hydrocarbons products was made using GC-MS and PTR-MS. p-cymene has been observed from the reactions of ?-pinene and limonene. Possible mechanisms will be presented and the atmospheric implications discussed.

  3. Electrobioremediation of Patagonian Soils Contaminated with Hydrocarbons

    Scientific Electronic Library Online (English)

    G.N., Pucci; A.J., Acuña; L.Y., Wick; O.H., Pucci.

    2012-09-01

    Full Text Available The electrokinetic technique is used to remediate hydrocarbon-contaminated soil. The aim of this paper is to evaluate the feasibility of using this technology to remediate oil- contaminated soils in the Gulf of San Jorge. The soils used in this experiment were unsaturated soils contaminated by oil f [...] ield operations being carried out in the area and previously remediated by landfarming. A potential difference of 0.5V cm-1 was applied to the electroremediation cells for 120 days; bridges of phosphate salt were used for the cells. Total hydrocarbons decreased from 4.22% to 3%, modifying the percentages of aliphatic, aromatic and polar hydrocarbons. The pH changed from 7.96 to 8.6 and 7.1 in the cathode and anode, respectively. The final pH values were compatible with the degrading bacterial community, whose colony-forming numbers did not present any alteration. On the cathode, there was an increase in the percentage of Gram-positive bacteria. Most of the species isolated were identified as Microbacterium luteus.

  4. Dihydrodiol dehydrogenase and polycyclic aromatic hydrocarbon metabolism

    International Nuclear Information System (INIS)

    Carcinogenic activation of polycyclic aromatic hydrocarbons by microsomal monoxygenases proceeds through trans-dihydrodiol metabolites to diol-epoxide ultimate carcinogens. This thesis directly investigated the role of dihydrodiol dehydrogenase, a cytosolic NAD(P)-linked oxidoreductase, in the detoxification of polycyclic aromatic trans-dihydrodiols. A wide variety of non-K-region trans-dihydrodiols were synthesized and shown to be substrates for the homogeneous rat liver dehydrogenase, including several potent proximate carcinogens derived from 7,12-dimethylbenz[a]anthracene, 5-methylchrysene, and benzo[a]pyrene. Since microsomal activation of polycyclic aromatic hydrocarbons is highly stereospecific, the stereochemical course of enzymatic trans-dihydrodiol oxidation was monitored using circular dichroism spectropolarimetry. The major product formed from the dehydrogenase-catalyzed oxidation of the trans-1,2-dihydrodiol of naphthalene was characterized using UV, IR, NMR, and mass spectroscopy, and appears to be 4-hydroxy-1,2-naphthoquinone. Mass spectral analysis suggests that an analogous hydroxylated o-quinone is formed as the major product of benzo[a]pyrene-7,8-dihydrodiol oxidation. Enzymatic oxidation of trans-dihydrodiols was shown to be potently inhibited by all of the major classes of the nonsteroidal antiinflammatory drugs. Enhancement of trans-dihydrodiol proximate carcinogen oxidation may protect against possible adverse effects of the aspirin-like drugs, dverse effects of the aspirin-like drugs, and help maintain the balance between activation and detoxification of polycyclic aromatic hydrocarbons

  5. Recovering hydrocarbons with surfactants from lignin

    Energy Technology Data Exchange (ETDEWEB)

    Naae, D.G.; Whittington, L.E.; Ledoux, W.A.; Debons, F.E.

    1988-11-29

    This patent describes a method of recovering hydrocarbons from an underground hydrocarbon formation penetrated by at least one injection well and at least one production well, which comprises: injecting into the formation through an injection well a surfactant slug comprising about 0.1% to about 10% by weight of surfactants produced from lignin, the surfactants produced by placing lignin in contact with water, converting the lignin into low molecular weight lignin phenols by reducing the lignin in the presence of a reducing agent of carbon monoxide or hydrogen creating a reduction reaction mixture comprising oil soluble lignin phenols, the reduction occurring at a temperature greater than about 200/sup 0/C and a pressure greater than about 100 psi, recovering the oil soluble lignin phenols from the reduction mixture, and converting the lignin phenols into lignin surfactants by a reaction selected from the group consisting of alkoxylation, sulfonation, sulfation, aklylation, sulfomethylation, and alkoxysulfation; injecting into the formation through the injection well a drive fluid to push the surfactant slug towards a production well; and recovering hydrocarbons at the production well.

  6. Adsorption of hydrocarbons in chalk reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Madsen, L.

    1996-12-31

    The present work is a study on the wettability of hydrocarbon bearing chalk reservoirs. Wettability is a major factor that influences flow, location and distribution of oil and water in the reservoir. The wettability of the hydrocarbon reservoirs depends on how and to what extent the organic compounds are adsorbed onto the surfaces of calcite, quartz and clay. Organic compounds such as carboxylic acids are found in formation waters from various hydrocarbon reservoirs and in crude oils. In the present investigation the wetting behaviour of chalk is studied by the adsorption of the carboxylic acids onto synthetic calcite, kaolinite, quartz, {alpha}-alumina, and chalk dispersed in an aqueous phase and an organic phase. In the aqueous phase the results clearly demonstrate the differences between the adsorption behaviour of benzoic acid and hexanoic acid onto the surfaces of oxide minerals and carbonates. With NaCl concentration of 0.1 M and with pH {approx_equal} 6 the maximum adsorption of benzoic acid decreases in the order: quartz, {alpha}-alumina, kaolinite. For synthetic calcite and chalk no detectable adsorption was obtaind. In the organic phase the order is reversed. The maximum adsorption of benzoic acid onto the different surfaces decreases in the order: synthetic calcite, chalk, kaolinite and quartz. Also a marked difference in adsorption behaviour between probes with different functional groups onto synthetic calcite from organic phase is observed. The maximum adsorption decreases in the order: benzoic acid, benzyl alcohol and benzylamine. (au) 54 refs.

  7. Biotransformation of monoaromatic hydrocarbons under anoxic conditions

    International Nuclear Information System (INIS)

    Aromatic hydrocarbons contained in gasoline are environmental pollutants of particular concern since they are relatively soluble in water, many are toxic, and some are confirmed carcinogens, (e.g., benzene). Although most gasoline constituents are readily degraded in aerobic surface water systems, the groundwater environment associated with hydrocarbon spills is typically anaerobic, thus precluding aerobic degradation pathways. In the absence of oxygen, degradation of gasoline components can take place only with the utilization of alternate electron acceptors such as nitrate, sulfate, carbon dioxide, and possibly ferric iron or other metal oxides. Benzene, toluene, and xylene isomers were completely degraded by aquifer- or sewage sludge-derived microorganisms under dentrifying and methanogenic conditions. Recently, a pure culture was found to degrade toluene and m-xylene nitrate or nitrous oxide as an electron acceptor. This paper presents initial results of ongoing study to develop and characterize microbial consortia capable of transforming aromatic hydrocarbons under nitrate-reducing conditions, and understand the effect of environmental factors on the biotransformation processes

  8. Radiolytic degradation of chlorinated hydrocarbons in water

    International Nuclear Information System (INIS)

    Radiolytic degradation of chlorinated hydrocarbons (chloroform, trichloroethylene, and tetrachloroethylene) in water was carried out. Water solutions of the chlorinated hydrocarbons with different concentrations were irradiated with ? rays. Concentrations of methane, ethane, CO, CO2, H2, and O2 after the irradiation were determined by gas chromatography. Concentration of chloride ion in the irradiated sample was determined by ion chromatography. Experimental results show that radiolytic degradation of the chlorinated hydrocarbon increased with the radiation dose. Methane, ethane, CO2, H2, and Cl- concentrations increased with the radiation dose and the sample concentration. On the other hand, O2 concentration decreased with the radiation dose and the sample concentration. When sample concentration was high, dissolved oxygen might be not enough for converting most of the C atoms in the sample into CO2. This resulted in a low decomposition ratio. Addition of H2O2 as an oxygen resource could increase the decomposition ratio greatly. Furthermore, gas chromatography-mass spectroscopy was applied to identify some intermediates of the radiolytic dehalogenation. Radiolytic degradation mechanisms are also discussed. (author)

  9. Verification and improvement of predictive algorithms for radionuclide migration

    International Nuclear Information System (INIS)

    This research addresses issues relevant to numerical simulation and prediction of migration of radionuclides in the environment of nuclear waste repositories. Specific issues investigated are the adequacy of current numerical codes in simulating geochemical interactions affecting radionuclide migration, the level of complexity required in chemical algorithms of transport models, and the validity of the constant-k/sub D/ concept in chemical transport modeling. An initial survey of the literature led to the conclusion that existing numerical codes did not encompass the full range of chemical and physical phenomena influential in radionuclide migration. Studies of chemical algorithms have been conducted within the framework of a one-dimensional numerical code that simulates the transport of chemically reacting solutes in a saturated porous medium. The code treats transport by dispersion/diffusion and advection, and equilibrium-controlled proceses of interphase mass transfer, complexation in the aqueous phase, pH variation, and precipitation/dissolution of secondary solids. Irreversible, time-dependent dissolution of solid phases during transport can be treated. Mass action, transport, and sorptive site constraint equations are expressed in differential/algebraic form and are solved simultaneously. Simulations using the code show that use of the constant-k/sub D/ concept can produce unreliable results in geochemical transport modeling. Applications to a field test and laboratory analogs of a nuclear waste repository indicate that a thermodynamically based simulator of chemical transport can successfully mimic real processes provided that operative chemical mechanisms and associated data have been correctly identified and measured, and have been incorporated in the simulator. 17 references, 10 figures

  10. Gas migration through crystalline rocks

    International Nuclear Information System (INIS)

    Fractured rocks have been considered as potential host rocks for the deep disposal of radioactive waste in a number of countries. The representative repository concepts involved: a) Low- and intermediate-level waste in water-saturated fractured rock. b) Spent fuel (or HLW) in water-saturated fractured rock. c) Spent fuel in unsaturated fractured tuff (Yucca Mountain). The key gas-related issues are likely to be different for these three repository concepts. Concept (a) typically involves the emplacement of packaged wastes in caverns or tunnels, probably backfilled with a cement grout, and perhaps involving structural concrete lining. The quantities of gas produced for a given volume of waste are expected to be larger than for spent fuel or high-level waste and may include radioactive gases whose release at the surface requires assessment for its potential radiological consequences. For this concept, understanding the mechanisms and effects of gas migration through the geosphere is important in repository performance assessment. For concept (b), the waste is typically contained in long-lasting canisters emplaced in holes lined with compacted bentonite. The bentonite barriers are intended to provide the main barrier to groundwater access to the waste, and the quantities of gas expected to be produced are predicted to be sufficiently small that the host rock is not expected to provide a serious obstacle to gas escape from the region of the canister. In this concept, the ion of the canister. In this concept, the main barrier to gas migration is considered to be the bentonite buffer; gas migration through this is discussed in a companion paper. Concept (c) is unique in involving emplacement of wastes in unsaturated rock, well above the water table, in a semi-arid region at Yucca Mountain in Nevada. Here the two-phase flow issues relate primarily to the infiltration of water through the fractured rock from the surface, which may involve flow channelling and intermittent flow, and the generation of strongly heat-driven flows, with extensive vaporization and condensation phenomena, caused by the emplacement of heat-generating wastes

  11. A simple method for calculating growth rates of petroleum hydrocarbon plumes

    Science.gov (United States)

    Bekins, B.A.; Cozzarelli, I.M.; Curtis, G.P.

    2005-01-01

    Consumption of aquifer Fe(III) during biodegradation of ground water contaminants may result in expansion of a contaminant plume, changing the outlook for monitored natural attenuation. Data from two research sites contaminated with petroleum hydrocarbons show that toluene and xylenes degrade under methanogenic conditions, but the benzene and ethylbenzene plumes grow as aquifer Fe(III) supplies are depleted. By considering a one-dimensional reaction front in a constant unidirectional flow field, it is possible to derive a simple expression for the growth rate of a benzene plume. The method balances the mass flux of benzene with the Fe(III) content of the aquifer, assuming that the biodegradation reaction is instantaneous. The resulting expression shows that the benzene front migration is retarded relative to the ground water velocity by a factor that depends on the concentrations of hydrocarbon and bioavailable Fe(III). The method provides good agreement with benzene plumes at a crude oil study site in Minnesota and a gasoline site in South Carolina. Compared to the South Carolina site, the Minnesota site has 25% higher benzene flux but eight times the Fe(III), leading to about one-sixth the expansion rate. Although it was developed for benzene, toluene, ethylbenzene, and xylenes, the growth-rate estimation method may have applications to contaminant plumes from other persistent contaminant sources. Copyright ?? 2005 National Ground Water Association.

  12. Automatic reduction of the hydrocarbon reaction mechanisms in fusion edge plasmas

    International Nuclear Information System (INIS)

    For predictions of the tritium inventory in future fusion devices like ITER, the amount of eroded carbon and the hydrogen concentrations in co-deposited hydrocarbon layers have to be predicted quantitatively. Predictions about the locations of co-deposited layers are also necessary in order to design deposition diagnostics and layer removal methods. This requires a detailed physical understanding of the erosion and carbon migration processes, and computer simulations. For accurate simulation the multi-species code EIRENE would require to include over 50 participating species. Because such a calculation is computationally prohibitive current codes are being reduced, typically in an ad hoc fashion. In this work the potential of the mathematically sound method of intrinsic low dimensional manifolds (ILDM) for computational speed-up of the hydrocarbon transport problem simulation is thoroughly investigated. It is basically the Monte Carlo implementation of EIRENE that makes this task so challenging. As the method can substantially ameliorate the results in comparison to the conventional reduction mechanisms a step towards ILDM-reduced kinetics is conceived and tested. (orig.)

  13. Contamination of soils and groundwater by petroleum hydrocarbons and volatile organic compounds - Case study: ELSLAV BRNO

    Directory of Open Access Journals (Sweden)

    Kone?ný F

    2003-09-01

    Full Text Available The complex system of interactions between basic environmental components is very often complicated by anthropogenic pollution. Petroleum hydrocarbons and volatile organic compounds represent the most frequent pollutants in the area of the Czech Republic. Our attention was therefore focused especially on these substances. Model reference locality of ELSTAV, Ltd. on Jílkova Street in Brno (former MEZ was chosen for the monitoring of capture, release, degradation, persistent fixation and migration of dangerous pollutants (VOC - volatile organic compounds and TPH - total petroleum hydrocarbons under surficial conditions of incoherent sediments. Activities performed within the scope of research works include drilling works, hydrodynamic test, soil and ground-water sample collection and laboratory analyses. A brief overview containing physical and chemical properties of chosen pollutants, their behaviour in soils and ground water and their impact on human health and the environment was also completed.
    The findings obtained during the research works at the chosen contamination site and from laboratory analyses are in agreement with information gained from the literature. It appears that TPH contamination of loamy sediments is relatively stable and the contaminant mobility is negligible.

  14. UNSW Embryology: movies of germ cell migration

    Science.gov (United States)

    Dr. Mark Hill (University of New South Wales Anatomy)

    2007-12-31

    Timelapse movies showing GFP labeled primordial germ cells during migration in the mouse from Mark Hill''s site courtesy of Molyneaux KA (Molyneaux KA, Stallock J, Schaible K, Wylie C. [See Related Articles] Time-lapse analysis of living mouse germ cell migration. Dev Biol. 2001 Dec 15;240(2):488-98).

  15. Parental Migration and Children's Outcomes in Romania

    Science.gov (United States)

    Robila, Mihaela

    2011-01-01

    Although Eastern European migration has increased greatly, the research on its impact on children and families has been limited. In this study I examined the impact of parental economic migration on children psychosocial and academic outcomes in Romania, one of largest Eastern European migrant sending country. Surveys were conducted with 382…

  16. Rethinking international migration: a review and critique.

    Science.gov (United States)

    Papademetriou, D G

    1983-01-01

    A new style of international migration, temporary and often illegal immigration in order to work, began to emerge after World War II. Many countries initiated immigration policies that gave the appearance of control, while their back doors remained open and, possibly, unclosable. In the US, it is slowly becoming obvious that foreign workers cannot be used as a temporary labor force at will. 2 usual theories of migration are the classical and the conflicts schools. The classical school presents migration as a rational, economic act that leads to economic adjustment between sending and receiving countries. The conflict school, often Marxist, views migration as an unequal process that leads to the inclusion of developing countries into the world capitalist system and to a widenin gap between rich and poor countries. The convergence of these 2 theories leads to the idea that although migration may be a survival strategy of individuals and households, it is also determined by a country's integration in the world economic system. The author reviews several books on immigration theory, which appreciate the complexity and worldwide character of migration; indicate that migration patterns are persistent; and support the view that migration is an economic, social, and political problem; and recommend that policies must be integrated and address the entire issue. PMID:12280186

  17. Labor and Migration; An Annotated Bibliography.

    Science.gov (United States)

    Brooks, Thomas R.

    This annotated bibliography is intended to contribute toward an understanding of labor and migration, both of which have helped to shape our nation. A total of 131 works, including a few periodicals and newspapers, focus on immigration and internal migration as it affects organized and unorganized labor. (BH)

  18. Ehrlichia-infected ticks on migrating birds.

    OpenAIRE

    Bjöersdorff, A.; Bergström, S.; Massung, R F; Haemig, P. D.; Olsen, B.

    2001-01-01

    During the spring of 1996, an estimated 581,395 Ehrlichia-infected ticks were imported into Sweden by migrating birds. Ehrlichia gene sequences found in ticks collected from these migrating birds were identical to those of granulocytic ehrlichiosis found in domestic animals and humans in Sweden. These findings support the idea that birds may play a role in dispersing Ehrlichia.

  19. International migration and human capital formation

    OpenAIRE

    Jellal, Mohamed; Wolff, François Charles

    2003-01-01

    We consider a model of international migration with heterogeneity in the skill level of workers which accounts for country?specific educational investment, unemployment expectations and return to the origin country. We prove that migrants invest less than natives in human capital formation because of return migration, so that migrants are more likely to be unemployed and to have flatter earnings profiles.

  20. SHARPIN Regulates Uropod Detachment in Migrating Lymphocytes

    Directory of Open Access Journals (Sweden)

    Jeroen Pouwels

    2013-11-01

    Full Text Available SHARPIN-deficient mice display a multiorgan chronic inflammatory phenotype suggestive of altered leukocyte migration. We therefore studied the role of SHARPIN in lymphocyte adhesion, polarization, and migration. We found that SHARPIN localizes to the trailing edges (uropods of both mouse and human chemokine-activated lymphocytes migrating on intercellular adhesion molecule-1 (ICAM-1, which is one of the major endothelial ligands for migrating leukocytes. SHARPIN-deficient cells adhere better to ICAM-1 and show highly elongated tails when migrating. The increased tail lifetime in SHARPIN-deficient lymphocytes decreases the migration velocity. The adhesion, migration, and uropod defects in SHARPIN-deficient lymphocytes were rescued by reintroducing SHARPIN into the cells. Mechanistically, we show that SHARPIN interacts directly with lymphocyte-function-associated antigen-1 (LFA-1, a leukocyte counterreceptor for ICAM-1, and inhibits the expression of intermediate and high-affinity forms of LFA-1. Thus, SHARPIN controls lymphocyte migration by endogenously maintaining LFA-1 inactive to allow adjustable detachment of the uropods in polarized cells.