WorldWideScience
 
 
1

A Model of Secondary Hydrocarbon Migration As a Buoyancy-Driven Separate Phase Flow Un modèle de migration secondaire des hydrocarbures considéré comme un écoulement en phases séparées régi par la poussée d'Archimède  

Directory of Open Access Journals (Sweden)

Full Text Available A mathematical model of secondary migration is described which permits the prediction of hydrocarbon migration and accumulation patterns in a sedimentary basin, if source rock expulsion rates and geometrical and hydraulic properties of major carrier systems are known through geological time. In this model, secondary migration is treated as buoyancy-driven, segregated flow of hydrocarbons in hydrostatic aquifers. Lateral, updip migration is conceived as a Boussinesq-type, free-surface flow, with source and sink terms representing supply from source rocks and leakage through cap rocks and faults. This permits a two-dimensional, map-view mathematical description of a three-dimensional, time-dependent secondary migration system. A nine-point finite difference approximation has been developed to minimize numerical dispersion, and upstream-weighting is used to obtain stable solutions. Example computations for simple, single carrier bed structures are presented. L'article décrit un modèle mathématique de migration secondaire prédisant la migration des hydrocarbures et leur accumulation dans un bassin sédimentaire, lorsque les taux d'expulsion des roches mères et les propriétés géométriques et hydrauliques des principaux systèmes de drainage sont connus à l'échelle du temps géologique. Dans ce modèle, la migration secondaire est traitée comme un écoulement des hydrocarbures en phase séparée, contrôlé par la poussée d'Archimède, dans des aquifères hydrostatiques. La migration latérale est considérée comme un écoulement de type Boussinesq, à surface libre, avec des termes sources et puits représentant les apports venant des roches mères et les fuites à travers les couvertures et les failles. Ceci permet une description mathématique bidimensionnelle cartographiable d'un système de migration secondaire tridimensionnel et dépendant du temps. On utilise une approximation type différences finies à neuf points pour minimiser la dispersion numérique et une pondération amont pour obtenir des solutions stables. Des exemples de calcul pour des structures simples avec une seule couche perméable sont présentés.

Lehner F. K.

2006-11-01

2

Finite Volume Method for Solving a Modified 3-D 3-Phase Black-Oil Hydrocarbon Secondary Migration Model, and Its Application to the Kuqa Depression of the Tarim Basin in Western China  

Digital Repository Infrastructure Vision for European Research (DRIVER)

By using a finite volume method as a solver, a modified 3-D 3-phase (water, oil, gas) black-oil model for modeling hydrocarbon (HC) secondary migration in the context of basin modeling is presented in this paper. The model predicts the quantity and distribution of HC accumulation in space and time. The black-oil model used in basin modeling is more complex and more difficult to model than that in reservoir simulations, as the model includes variable simulation ranges, very long simul...

Shi, Guangren; Ma, Jinshan; Yang, Xinshe; Chang, Junhua; Wan, Jun

2011-01-01

3

Unconformities: key to hydrocarbon migration and entrapment  

Energy Technology Data Exchange (ETDEWEB)

Unconformities caused by periodic changes in sea level are readily observed from seismic and log sections and facies models. Unconformities below the Simpson, Woodford, Morrowan, and the Wolfcampian granite wash are the controls for the accumulation of hydrocarbons. Patterns of truncation, onlap, topography, and structural history of these surfaces is the key to discovering new hydrocarbon accumulations in the Mid-Continent. Location of subtle traps associated with these unconformities has not been widely used in the Mid-Continent. Detecting hydrocarbon accumulations requires isopach mapping of intervals between event markers, both below and above the unconformity surface. These isopach maps provide information on timing and pattern of the structural history, topographic control for onlapping reservoir units, points for fluid migration into overlying onlapping sequences, and truncation of underlying reservoir units. Study of these maps indicates areas for hydrocarbon accumulations in various stratigraphic units, including the Simpson, Hunton, Misener, Mississippian carbonates, Morrowan, and a succession of onlapping Atokan and Desmoinesian rocks and in Wolfcampian granite wash.

Visher, G.S.

1987-08-01

4

Subsurface migration of petroleum hydrocarbons: A case study of immiscible migration and chromatographic separation  

International Nuclear Information System (INIS)

The subsurface distribution of a leaked crude oil illustrates the combined influence of both the chemical and physical properties of soil and free product on the migration of petroleum hydrocarbons. Immiscible phase behavior was observed, as well as chromatographic-like separation of the lighter constituents of the crude oil from the heavier constituents. After downward migration through approximately 50 ft of unsaturated, heterogeneous alluvial sediments, the crude oil formed a horizontal plume on top of a perched, saturated zone. Immiscible phase trapping is evident from the occurrence of very high concentration of hydrocarbons in both the vertical and horizontal plumes. Samples taken from the vertical zone of contamination indicate a transition from heavier hydrocarbons near the surface to lighter hydrocarbons at depth. This phenomenon is attributed to chromatographic-like separation of the heavier hydrocarbons by the soil, possibly due to preferential solubility of the lighter hydrocarbons in percolating ran water

5

Migration of polyolefin oligomeric saturated hydrocarbons (POSH) into food.  

Science.gov (United States)

POSH are polyolefin oligomeric saturated hydrocarbons, such as oligomers from polyethylene or polypropylene. POSH that have migrated into foods are easily mistaken for mineral oil-saturated hydrocarbons (MOSH). In fact, both POSH and MOSH largely consist of highly isomerised branched and possibly cyclic hydrocarbons, both forming humps of unresolved components in gas chromatography. Chromatograms are reported to show typical elution patterns of POSH and help analysts distinguishing POSH from MOSH as far as possible. Since the structures of the POSH are not fundamentally different from those of the MOSH, it would be prudent to apply the evaluation of the MOSH. However, the migration is frequently beyond that for which safety has been demonstrated. This is shown for a few examples, particularly for powdered formula for babies. PMID:22243490

Biedermann-Brem, S; Kasprick, N; Simat, T; Grob, K

2012-01-01

6

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)

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.

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

2014-08-01

7

Hydrocarbon generation and brine migration in the central Appalachian basin  

Energy Technology Data Exchange (ETDEWEB)

Fluid inclusions in mineralized natural fractures from six Devonian shale cores were used to document hydrocarbon generation and brine migration in the central Appalachian basin. The sequence of formation of four regional fracture sets containing the inclusions was used to constrain the relative timing of fluid evolution. The earliest formed fluid inclusions are single-phase liquid inclusions containing a complex mixture of methane, ethane, higher hydrocarbons, and nitrogen. These inclusions formed during burial of the Devonian shales and early hydrocarbon generation in the oil window. As burial proceeded to a maximum and hydrocarbon generation entered the gas phase, later formed fluid inclusions record the presence of a more methane-rich fluid with minor ethane and nitrogen. Either during maximum burial or early uplift of the Devonian shale section, regional stress relaxation was accompanied by regional brine migration. Fluid inclusions record the influx of a methane-saturated, sodium chloride-rich brine and subsequent mixing with a presumably in situ-calcium-rich brine and subsequent mixing with a presumably in-situ calcium-rich brine. The migration pathway is presumed to be the Devonian shale detachment zone and underlying Devonian Oriskany Sandstone. This migration may be related to the fluids forming Mississippi Valley-type ore deposits. Present-day brine compositions reflect this ancient mixing. Brines from deep Cambrian through Silurian rocks are more calcium-chloride rich than brines from shallower Devonian and younger rocks. The sodium chloride-rich brines from Upper Devonian through Pennsylvanian rocks become more dilute as a result of mixing with meteoric water.

Evans, M.A. (Georgia Southern Univ., Statesboro (United States))

1991-08-01

8

Migration of selected hydrocarbon contaminants into dry pasta packaged in direct contact with recycled paperboard.  

Science.gov (United States)

This paper deals with the migration of selected hydrocarbon contaminants, namely mineral oil hydrocarbons (MOH), diisopropyl naphthalenes (DIPN) and polyalphaolefins (PAO) from adhesives into dry semolina and egg pasta packaged in direct contact with recycled paperboard. Migration was monitored during its shelf life (for up to two years) simulating storage in a supermarket (packs on shelves) and conditions preventing exchange with the surrounding environment (packs wrapped in aluminium foil). Migration from the secondary packaging (transport boxes of corrugated board) was also studied for semolina pasta. After 24 months of exposure, semolina pasta stored on shelves reached 3.2 and 0.6 mg kg(-1) of MOSH and MOAH, respectively, Migration from the adhesives used to close the boxes and from the transport boxes contributed about 30% and 25% of the total contamination, respectively. The highest contamination levels (14.5 and 2.0 mg kg(-1) of MOSH and MOAH, respectively, after 24 months) were found in egg pasta stored on shelves (no adhesives), and seemed due to the highest contribution from the external environment. PMID:25571955

Barp, Laura; Suman, Michele; Lambertini, Francesca; Moret, Sabrina

2015-02-01

9

SECONDARY ORGANIC AEROSOL FORMATION FROM MIXTURES OF BIOGENIC HYDROCARBONS  

Science.gov (United States)

In this work the influence of hydrocarbon mixtures on the overall Secondary Organic Aerosol yield is investigated. Photochemical reaction experiments were conducted using mixtures of a-pinene, isoprene and propene in the presence of NOx. Results of the experiments show...

10

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)

11

Arsenic cycling in hydrocarbon plumes: secondary effects of natural attenuation  

Science.gov (United States)

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.

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

2015-01-01

12

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

Directory of Open Access Journals (Sweden)

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.

Chiarelle A.

2006-11-01

13

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

1985-12-01

14

Migration of hydrocarbons in the subsoil of an industrial installation  

International Nuclear Information System (INIS)

The fate of old industrial sites is a major problem at the beginning of the new millennium for government organization, agencies owning polluted sites... These brown-field sites often generate considerable pollution of soils and groundwater, the main source of drinking water. The National Center for Research on Polluted Soils and Sites (CNRSSP), in which the CEA is an active partner, is developing a strategy to study and, using several scientific tools, characterize industrial sites polluted by various contaminants: metals, metalloids, hydrocarbons, nitrates. The present study offers an example of the investigation of an old industrial site (coke plant), built in 1919 (in operation for 50 years), located in northern France. The storage of tars and wastewaters on these sites causes soil and groundwater contamination with organic compounds such as Polycyclic Aromatic Hydrocarbons (PAHs), mono-aromatic hydrocarbons (benzene, toluene, ethyl-benzene and xylene BTEX), volatile organic compounds (VOCs), phenolic and other hydrocarbons, and inorganic compounds including metalloids (free and complexed cyanides) and metals (As, Pb, Ni, Cd and Hg). The more soluble constituents tend to migrate to adjacent areas with the groundwater flow and thereby reach receptors such as drinking water resources. Among the above pollutants, the 16 PAHs from the priority list of the Environmental Protection Agency (EPA) are of great environmental concern due to their toxic, mutagenic and carcinogenic properties. The remediation of PAH-polluted sites poses a crucial challenge given the large number of sites contaminated by these pollutants and the difficulty in eliminating the pollution. A better evaluation of the PAH transfer and transport in soils and aquifers will also help draw up remediation strategies. In this study, a numerical model, called SIMUSCOPP and developed by the French Petroleum Institute (IFP), BURGEAP and ENI group for organic pollutants, was used to simulate 3D transfer and transport of PAHs under an old coke plant, taking biodegradation and soil sorption into account. The simulation results discussed in this paper were obtained by assuming tar pollution 7 m deep underground to be the only source. This aquifer pollution in a chalky formation mainly consists of PAHs (naphthalene, fluoranthene, etc). A broad field investigation was conducted on the site by monitoring the water (16 piezometers, piezometric measurements, pollutant concentration analysis) to characterize the location and extent of the PAH plume. The numerical modeling was aimed to characterize PAH migration in the unsaturated and saturated zones and to assess the vulnerability of a drinking water well located downstream. The model helped estimate the time for dissolved naphthalene to reach steady state (20 years) and the plume dimensions (1200 m long, 300 m wide and 15 m thick). Simulation were performed of water samplings in piezometers inside and outside the polluted area and the naphthalene concentration in water samples was reproduced, in good agreement with real observations on boreholes of the site. However, for two piezometers located between the two lagoons of coal tars, a large contribution of a second source of PAH, enriched in PAHs with 2 or 3 rings and located at the base of aquifer, was identified in water samples, in the pumped water. This significant share of the pollution is not transported with groundwater flow, but only with water pumping. Thus SIMUSCOPP served to identify the dissolved phase of PAH and to quantify the rest of the pollution, possibly a colloidal phase. As a consequence, a new water sampling strategy could be developed in order to adjust the pump discharge, use specific filters, etc. The major conclusion of the transport simulation is that the PAH plume does not reach the drinking water well located 4 km downstream of the site. However, some remediation measures are necessary and the polluted soils are currently being excavated. (author)

15

Modeling free product migration and recovery at hydrocarbon spill sites  

International Nuclear Information System (INIS)

The numerical model ARMOS, which simulates areal flow of water and light hydrocarbon in an unconfined aquifer, is described. Based on the assumption of local vertical equilibrium, areal flow equations for water and hydrocarbon are derived which exhibit reduced dimensionality and nonlinearity. A finite-element method is used to solve the water and oil equations using an efficient semidecoupled approach. Input required by the model includes areal boundaries, elevations of the aquifer lower boundary, and initial water and hydrocarbon levels in monitoring wells. Soil and fluid properties include hydrocarbon density, viscosity and surface tension, saturated hydraulic conductivity, van Genuchten air-water capillary pressure curve parameters, and the maximum residual hydrocarbon saturations in the saturated and unsaturated zones. Fluid heads or fluxes may be specified on the domain perimeter and pumping rates are prescribed at recovery wells. The water pumping rate is automatically limited when drawdown reaches a pump-off set point (or the screen bottom), and hydrocarbon recovery is limited when well hydrocarbon thickness becomes zero. Model output includes water and hydrocarbon levels in monitoring wells, cumulative product recovery, and free and residual hydrocarbon volumes in the soil. A hypothetical problem involving optimization of free product recovery and a field application of the model to a large pipeline leak are described

16

Migration of mineral hydrocarbons into foods. 1. Polystyrene containers for hot and cold beverages.  

Science.gov (United States)

Mineral hydrocarbons are used as processing aids at levels between 0.3 and 3% by weight in crystal polystyrene articles, the food contact uses of which include the dispensing of hot and cold beverages from automatic machines as well as in 'fast-food' and catering establishments. The levels of migration of mineral hydrocarbons from polystyrene cups and glasses have been measured into aqueous food simulants as well as lager, beer, cola, sparkling apple juice, lemon barley water, coffee, hot chocolate, tea, lemon tea and chicken soup. For the cold beverages and simulants, no migration above 0.1 mg/kg was observed, and for the hot beverages and simulants no result greater than 0.5 mg/kg. Analysis was by capillary gas chromatography, using hydrocarbon internal standards calibrated against mineral hydrocarbon reference standards. PMID:1812015

Castle, L; Kelly, M; Gilbert, J

1991-01-01

17

Migration of mineral hydrocarbons into foods. 3. Cheese coatings and temporary casings for skinless sausages.  

Science.gov (United States)

Levels of mineral hydrocarbons which have migrated from wax coatings into cheese have been determined for 20 retail samples using a gas chromatographic procedure. Contamination was limited to the outermost 2 mm of cheese in direct contact with the wax where levels of hydrocarbons were found to range from 10 to 150 mg/kg. On a whole cheese weight basis these amounted to beef, pâté, sausage meat and sausages with skins. Levels of mineral oil in these products were insignificant by comparison, typically below the limit of detection of ca 4 mg/kg, indicating insignificant adventitious contamination from routes other than migration. PMID:8314395

Castle, L; Kelly, M; Gilbert, J

1993-01-01

18

Modeling the Role of Alkanes, Polycyclic Aromatic Hydrocarbons, and Their Oligomers in Secondary Organic Aerosol Formation  

Science.gov (United States)

A computationally efficient method to treat secondary organic aerosol (SOA) from various length and structure alkanes as well as SOA from polycyclic aromatic hydrocarbons (PAHs) is implemented in the Community Multiscale Air Quality (CMAQ) model to predict aerosol concentrations ...

19

Numerical modeling of compositional variation in petroleum secondary migration; Modelagem numerica da variacao composicional na migracao secundaria de petroleo  

Energy Technology Data Exchange (ETDEWEB)

The secondary migration of petroleum is analyzed in this study from a compositional perspective, with phase separation, using a numerical simulator. The modeling is focused on two different geologic scenarios, where migration occurs along the formation rocks or through a fault. Each scenario is initialized with a single-phase hydrocarbon bank, with mixtures defined in the oil and gas zones and in the proximity of the critical point in their respective phase envelopes. These fluids are obtained using a PVT simulator based on four samples (Black-oil, volatile oil and two retrograde gases) which generate various hydrocarbon mixtures from which some are selected to meet the pressure and temperature conditions established for the models. The results obtained indicate that the phase separation process, the migration and the oil and gas differences are adequately represented, and that this type of modeling may be used to explain complex fluid distribution in a single accumulation or petroleum province. However, the analysis of post-filling processes indicate the need for the inclusion of a diffusive term in the flow equations used in the simulator and for a higher precision in the fluid properties outputs. (author)

Magalhaes, Marcia Santos de Almeida

1999-07-01

20

2D modelling of hydrocarbon migration along and across growth faults: an example from Nigeria  

Energy Technology Data Exchange (ETDEWEB)

Temis 2D was used to study hydrocarbon migration and fluid distribution in an area of the Niger Delta. In this setting, high pressures are related to a high sedimentation rate, and pressure compartments are delineated by growth faults. A growth fault is regarded as a hydro-mechanically active zone contributing both to a release of high pressures and to hydrocarbon migration from the deep mature source rocks to shallower reservoirs. Overpressures are generated in confined systems where water flow is extremely low. The most significant parameters causing the generation of overpressures are very low shale permeability and rapid burial. In 2D modelling, pressure calibration is obtained by adjusting cap-rock permeability and by properly simulating reservoir connectivity. The accuracy of fluid flow simulation is highly dependent on lateral transmissibility across reservoirs and/or faults. When pore pressure reaches fracture pressure, the vertical permeability in the model must be increased to simulate release of the excess pore pressure by fracturing. Simulating hydrocarbon migration, which is dependent on both permeability and capillary pressure, from a high-pressure domain to a lower pressure domain without losing the pressure distribution, requires a detailed geological model and a thorough calibration. In a deltaic system, such as the Niger Delta, a growth fault behaves as a complex zone for fluid flow, due to a relatively low horizontal permeability and a significant transient vertical permeability. In detail, permeability and capillary pressures in the fault zone are dependent on clay content (clay smearing) along the fault, possible cataclasis reducing sandstone permeability, and lithology juxtaposition, forming a complex structure along which fluids have to move. In this approach the fault is considered as a permanent active zone with transient fluid and pressure transfers, implying hydro-mechanical coupling. The aim of 20 basin modelling is to simulate the geological history of a petroleum system in order to understand and quantify the hydrocarbon generation, migration and trapping. As a control of a correct simulation, the main hydrocarbon-bearing reservoirs must be restored with correct temperature, pore pressure, saturation and gas:oil ratio (GOR). The results of the present simulation show that all these parameters, and particularly pore pressures and GOR, are in accordance with well data. Fluid flow modelling allows vertical migration of the hydrocarbons from the deep overpressured domain to the hydrostatic domain, and a partial lateral transfer between adjacent reservoirs, without full pressure equalization. The model correctly predicts hydrocarbons in the main reservoirs and the appropriate GOR, even though local variations are not well simulated. Abnormally high pressures are maintained within the system even though fluid flow and hydrocarbon migration are simulated in a dynamic mode. The thorough geological description of the fault zone, which allows a detailed input of petrophysical parameters, is the key to such a result. (Author)

Caillet, G. [TotalFinaElf, Exploration and Production, Pau, 64 (France); Batiot, S. [IGAL, Paris (France)

2003-01-01

 
 
 
 
21

A novel molecular index for secondary oil migration distance  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Determining oil migration distances from source rocks to reservoirs can greatly help in the search for new petroleum accumulations. Concentrations and ratios of polar organic compounds are known to change due to preferential sorption of these compounds in migrating oils onto immobile mineral surfaces. However, these compounds cannot be directly used as proxies for oil migration distances because of the influence of source variability. Here we show that for each source facies, the ratio of the...

Liuping Zhang; Maowen Li; Yang Wang; Qing-Zhu Yin; Wenzheng Zhang

2013-01-01

22

Origin of gasoline-range hydrocarbons and their migration by solution in carbon dioxide in Norton basin, Alaska.  

Science.gov (United States)

Carbon dioxide from a submarine seep in Norton Sound carries a minor component of gas- and gasoline-range hydrocarbons. The molecular and isotopic compositions of the hydrocarbon gases and the presence of gasoline-range hydrocarbons indicate that these molecules are derived from thermal alteration of marine and/or nonmarine organic matter buried within Norton basin. The gasoline-range hydrocarbon distribution suggests that the hydrocarbon mixture is an immature petroleum-like condensate of lower temperature origin than normal crude oil. The submarine seep provides a natural example in support of a carbon dioxide solution transport mechanism thought to be operative in the migration of hydrocarbons in certain reservoirs.-Authors

Kvenvolden, K.A.; Claypool, G.E.

1980-01-01

23

Origin and migration of hydrocarbon gases and carbon dioxide, Be??ke??s Basin, southeastern Hungary  

Science.gov (United States)

The Be??ke??s Basin is a sub-basin within the Pannonian Basin, containing about 7000 m of post-Cretaceous sedimentary rocks. Natural gases are produced from reservoirs (Precambrian to Tertiary in age) located on structural highs around the margins of the basin. Gas composition and stable carbon isotopic data indicate that most of the flammable gases were derived from humic kerogen contained in source rocks located in the deep basin. The depth of gas generation and vertical migration distances were estimated using quantitative source rock maturity-carbon isotope relationships for methane compared to known Neogene source rock maturity-depth relationships in the basin. These calculations indicate that as much as 3500 m of vertical migration has occured in some cases. Isotopically heavy (> - 7 > 0) CO2 is the predominant species present in some shallow reservoirs located on basin-margin structural highs and has probably been derived via long-distance vertical and lateral migration from thermal decompositon of carbonate minerals in Mesozoic and older rocks in the deepest parts of the basin. A few shallow reservoirs (< 2000m) contain isotopically light (-50 to -60%0) methane with only minor amounts of C2+ homologs (< 3% v/v). This methane is probably mostly microbial in origin. Above-normal pressures, occuring at depths greater than 1800 m, are believed to be the principal driving force for lateral and vertical gas migration. These pressures are caused in part by active hydrocarbon generation, undercompaction, and thermal decomposition of carbonates. ?? 1990.

Clayton, J.L.; Spencer, C.W.; Koncz, I.; Szalay, A.

1990-01-01

24

A novel molecular index for secondary oil migration distance  

Science.gov (United States)

Determining oil migration distances from source rocks to reservoirs can greatly help in the search for new petroleum accumulations. Concentrations and ratios of polar organic compounds are known to change due to preferential sorption of these compounds in migrating oils onto immobile mineral surfaces. However, these compounds cannot be directly used as proxies for oil migration distances because of the influence of source variability. Here we show that for each source facies, the ratio of the concentration of a select polar organic compound to its initial concentration at a reference point is independent of source variability and correlates solely with migration distance from source rock to reservoir. Case studies serve to demonstrate that this new index provides a valid solution for determining source-reservoir distance and could lead to many applications in fundamental and applied petroleum geoscience studies.

Zhang, Liuping; Li, Maowen; Wang, Yang; Yin, Qing-Zhu; Zhang, Wenzheng

2013-08-01

25

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

CERN Document Server

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...

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

2011-01-01

26

Late Palaeozoic hydrocarbon migration through the Clair field, West of Shetland, UK Atlantic margin  

Science.gov (United States)

Geochemical analysis of bitumen- and hydrocarbon-bearing fluid inclusions from the Devonian-Carboniferous Clair field indicates that the reservoirs contain a mixture of oils from different marine and lacustrine sources. Reconstruction of the Clair field oil-charge history using fluid inclusion petrography show that oil-charging occurred at times of K-feldspar, quartz and calcite cementation. Temperature-composition-time data yielded from the integration of fluid inclusion microthermometry with high-resolution Ar-Ar dating, date hydrocarbon-bearing K-feldspar overgrowths at 247 ± 3.3 Ma. These data show that in order for oil to be trapped within primary fluid inclusions in K-feldspar overgrowths, hydrocarbon migration throughout the UK Atlantic margin must have been taking place during the Late Palaeozoic and as such, current industry oil-play models based solely on oil charging from Jurassic-Cretaceous marine sources are clearly incomplete and need revision. Apatite fission track analysis and vitrinite reflectance data were used to reconstruct thermal burial histories and assess potential oil generation from Middle Devonian lacustrine source rocks. Thermal history data from wells along The Rona Ridge adjacent to the Clair field show that the Palaeozoic section was heated to greater than 100 °C at some time between 270 and 230 Ma, confirming that Devonian source rocks were mature and expelling oil during the Late Palaeozoic at the time that authigenic K-feldspar overgrowths were growing in the Clair field.

Mark, Darren F.; Green, Paul F.; Parnell, John; Kelley, Simon P.; Lee, Martin R.; Sherlock, Sarah C.

2008-05-01

27

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

Energy Technology Data Exchange (ETDEWEB)

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.

Wagner, G.

1997-12-31

28

Hydrocarbon generation and migration in the Nanpu Sag, Bohai Bay Basin, eastern China: Insight from basin and petroleum system modeling  

Science.gov (United States)

The hydrocarbon generation and migration history occurred in the Nanpu Sag, Bohai Bay Basin was investigated using basin and petroleum system modeling. The Eocene Es34 and Es1 members/submembers of the Shahejie Formation and the Oligocene Ed3 member of the Dongying Formation are the most important source rocks responsible for the major hydrocarbon accumulations in Nanpu Sag. One and two-dimensional basin modeling was performed to unravel the hydrocarbon generation and migration history of the three sets of source rocks based on the reconstruction of the burial, thermal, maturity and fluid potential history. The model was calibrated with thermal maturity and borehole temperature data and simulated results indicate that Es34, Es1, and Ed3 source rocks in Laoyemiao and Caofeidian sub-sags reached peaks of hydrocarbon generation at about 20 Ma, 10 Ma, and 0 Ma respectively. The fluid potential and flow line modeling revealed that nearly all the structural high were directions of hydrocarbon migration and formed favorable traps for whichever of the source rock strata. Multiple sub-sags oil-offering and compound faults caused oil mixture.

Guo, Yingchun; Pang, Xiongqi; Dong, Yuexia; Jiang, Zhenxue; Chen, Dongxia; Jiang, Fujie

2013-11-01

29

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.)

30

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

Energy Technology Data Exchange (ETDEWEB)

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.

Bharati, Sunil

1997-12-31

31

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

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

2014-01-01

32

Migration of mineral hydrocarbons into foods. 2. Polystyrene, ABS, and waxed paperboard containers for dairy products.  

Science.gov (United States)

Migration of mineral hydrocarbons into dairy products and sunflower oil (fatty food simulant) has been studied using a gas chromatographic procedure. The food contact materials examined were polystyrene and ABS pots and tubs, and waxed paperboard. Levels of mineral oil in the polystyrene and ABS articles ranged from 0.3 to 5.5% w/w (13 to 366 mg/dm2) and as a coating on the paperboard ranged from 1.0 to 7.7% (55 to 565 mg/dm2). Exposure conditions were 7 days at 4 degrees C for the dairy products and 10 days at 40 degrees C for the oil. However, individual serving milk and creams (UHT) were retail samples which were stored at ambient temperature before analysis. Migration into the milk products was less than 3 mg/kg. Transfer to sunflower oil simulant and into individual serving milk products was much higher at levels up to 150 mg/kg (2 mg/dm2) and 90 mg/kg (4 mg/dm2) for the oil and milk respectively. PMID:8314394

Castle, L; Kelly, M; Gilbert, J

1993-01-01

33

Hydrocarbon-water interactions during brine migration: Evidence from hydrocarbon inclusions in calcite cements from Danish North Sea oil fields  

Science.gov (United States)

Crude oils in primary and secondary fluid inclusions in calcite from fractures in seven offshore oil fields associated with diapiric salt structures in the Danish sector of the North Sea were analyzed by capillary column gas chromatography and compared with crude oils produced from the same reservoirs. Oils from fluid inclusions in all fields show evidence of biodegradation (decreased n-C17/pristane and n-C18/phytane ratios and loss of n-C7, 2-methyl hexane, and 3-methyl hexane relative to methyl cyclohexane) and water washing (absence of benzene and depletion of toluene). Some oils in inclusions are extremely enriched in C6 and C7 cyclic alkanes suggesting that these samples contain hydrocarbons exsolved from ascending, hotter formation waters. Compared to inclusion oils the produced oils are less biodegraded, but are water washed, indicating that both types of oil interacted with large volumes of formation water. The carbon isotopic composition of the calcite host of the fluid inclusions in the Dagmar and Skjold fields is as light as -16.5%. PDB and the sulfur isotopic composition of pyrite in and adjacent to the calcite veins in the Skjold field is as light as -39.6%. CDT, indicating that biodegradation of the oils was a source of some of the carbon in the calcite and sulfate reduction was the source of sulfur for the pyrite. The evidence for microbial degradation of petroleum is consistent with present-day reservoir temperatures (65??-96??C) but is not consistent with previous estimates of the temperatures of calcite vein filling (95??-130??C) which are much higher than the temperatures of known occurrences of biodegraded oil. ?? 1990.

Jensenius, J.; Burruss, R.C.

1990-01-01

34

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Venezuela | Language: Spanish Abstract in spanish 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.

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

2007-11-01

35

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

Energy Technology Data Exchange (ETDEWEB)

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.

Wagner, G.

1997-09-01

36

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

CERN Document Server

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 ...

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

2014-01-01

37

Secondary Aerosol Formation from Oxidation of Aromatics Hydrocarbons by Cl atoms  

Science.gov (United States)

Aerosol Formation From the Oxidation of Aromatic Hydrocarbons by Chlorine Atmospheric secondary organic aerosol (SOA) affects regional and global air quality. The formation mechanisms of SOA via the oxidation of volatile organic compounds by hydroxyl radicals, ozone, and nitrate radicals have been studied intensively during the last decade. Chlorine atoms (Cl) also have been hypothesized to be effective oxidants in marine and industrially influenced areas. Recent work by the authors has indicated that significant amounts of SOA are formed from the oxidation of monoterpenes by Cl. Aromatic hydrocarbons are important for generation of both SOA and ozone in urban areas because of their large emission rates and high reactivity. The goal of this work was to quantify the SOA formation potentials of two representative aromatic hydrocarbons through laboratory chamber experiments in which oxidation was initiated by Cl. The system constructed for this study includes an experimental chamber, a gas chromatograph for quantification of aromatic mixing ratios, a Scanning Mobility Particle Spectrometer to measure SOA size distributions, a zero air generator, and an illuminating system. The model aromatic hydrocarbons chosen for this study are toluene and m-xylene. Aerosol yields are estimated based on measured aerosol volume concentration, the concentration of consumed hydrocarbon, and estimation of wall loss of the newly formed aerosol. Toluene and m-xylene exhibit similar SOA yields from the oxidation initiated by Cl. The toluene SOA yield from Cl-initiated oxidation, however, depends on the ratio between the mixing ratios of the initial chlorine source and toluene in the chamber. For toluene experiments with higher such ratios, SOA yields vary from 0.05 to 0.079 for generated aerosol ranging from 4.2 to12.0 micrograms per cubic meter. In the lower ratio experiments, SOA yields are from 0.033 to 0.064, corresponding to generated aerosol from 3.0 to 11.0 micrograms per cubic meter. The m-xylene SOA yield ranges from 0.04 to 0.08 for aerosol in the range of 4.0 to 12.0 micrograms per cubic meter. These yields are generally comparable to those from photooxidation. In marine and industrial areas, SOA formation from the Cl- initiated oxidation of the studied common aromatics is likely to be most important in the early morning.

Cai, X.; Griffin, R.

2006-12-01

38

Influence of secondary formation on atmospheric occurrences of oxygenated polycyclic aromatic hydrocarbons in airborne particles  

Science.gov (United States)

Temporal and spatial variations in concentrations of particle-associated polycyclic aromatic hydrocarbons (PAHs) and their nitrated and oxygenated derivatives (nitro-PAHs and oxy-PAHs) were investigated to assess the influence of secondary formation on atmospheric occurrences of oxy-PAHs associated with particulate matter in downtown Tokyo, Japan. The daily variation in concentration of 1,8-naphthalic anhydride (1,8-NA) in summer 2007 was similar to that for 2-nitrofluoranthene (2-NF), a representative secondary formed nitro-PAH, while the variation for benzanthrone (BA) was similar to PAHs. In addition, the concentrations of polycyclic aromatic compounds (PACs) associated with airborne particulate matter decreased in the order of PAHs > BA > 9-fluorenone (9-FO) or 9,10-anthraquinone (9,10-AQ) > 1,8-NA with an increase in distance from the roadside, whereas 2-NF was constant. These results suggest that a considerable fraction of some oxy-PAHs such as 1,8-NA associated with airborne particulate matter in downtown Tokyo originates from atmospheric secondary formation.

Kojima, Yuki; Inazu, Koji; Hisamatsu, Yoshiharu; Okochi, Hiroshi; Baba, Toshihide; Nagoya, Toshio

2010-08-01

39

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...

40

Saline fluid flow and hydrocarbon migration and maturation as related to geopressure, Frio Formation, Brazoria County, Texas  

Energy Technology Data Exchange (ETDEWEB)

The Pleasant Bayou geopressured-geothermal test wells in Brazoria County, Texas, display a prominent thermal-maturity anomaly in the Oligocene Anahuac and Frio Formations. Highly geopressured, more-mature shales are interbedded with hydropressured to moderately geopressured sandstones in the upper Frio and Anahuac. In contrast, shales and sandstones in the lower Frio, including the Andrau geopressured-geothermal production zone, are highly geopressured but exhibit lower thermal maturities. Vitrinite-reflectance data, supported by hydrocarbon-maturation data and anomalous concentrations of C/sub 5/ to C/sub 7/ hydrocarbons at Pleasant Bayou, indicate that the upper Frio was subjected to an extended period of hot, extremely saline, basinal fluid flow which caused the above thermal anomaly. Regional salinity studies (Morton and others, 1983) suggest that regional growth faults were the conduits for vertical basinal brine movement at depth. At shallower levels the upwelling waters migrated laterally through permeable sandstone-rich sections such as the upper Frio. Anomalously mature gasoline-range (C/sub 5/-C/sub 7/) hydrocarbons were introduced into the upper Frio by this process. Fluid influx in the lower Frio was probably limited by high geopressure, consequently maturity in the deep Frio section (greater than 14,000 ft) remained consistent with the regional geothermal gradient.

Tyler, N.; Light, M.P.R.; Ewing, T.E.

1985-01-01

 
 
 
 
41

Effectiveness of phytoremediation as a secondary treatment for polycyclic aromatic hydrocarbons (PAHs) in composted soil.  

Science.gov (United States)

A greenhouse study was conducted over a 12-month period to investigate the fate of polycyclic aromatic hydrocarbons (PAHs) in soil using phytoremediation as a secondary treatment. The soil was pretreated by composting for 12 weeks, then planted with tall fescue (Festuca arundinacea), annual ryegrass (Lolium multiflorum), and yellow sweet clover (Melilotus officinalis). Two sets of unvegetated controls also were evaluated, one fertilized and one unfertilized. Total PAH concentrations decreased in the tall fescue, annual ryegrass, and yellow sweet clover treatments by 23.9%, 15.3%, and 9.1%, respectively, whereas the control was reduced by less than 5%. The smaller two- and most of the three-ringed compounds--naphthalene, acenaphthylene, acenaphthene, fluorene, and anthracene--were not found in detectable concentrations in any of the treatments. The most probable number analysis for microbial PAH degraders did not show any statistically significant differences among treatments. There were significant differences among treatments (p < 0.05) for the residual concentrations of five of the target PAHs. Root surface area measurements indicated that tall fescue and annual ryegrass both had significantly higher root surface area than yellow sweet clover, although the two species were not significantly different from each other. The tall fescue treatment resulted in the highest root and shoot biomass, followed by annual ryegrass and yellow sweet clover, and also had the highest percent of contaminant removal after 12 months. These results imply a positive relationship between plant biomass development and PAH biodegradation. PMID:15328979

Parrish, Zakia D; Banks, M Katherine; Schwab, A Paul

2004-01-01

42

Synergy between shear-induced migration and secondary flows on red blood cells transport in arteries: considerations on oxygen transport.  

Science.gov (United States)

Shear-induced migration of red blood cells (RBCs) is a well-known phenomenon characterizing blood flow in the small vessels (micrometre to millimetre size) of the cardiovascular system. In large vessels, like the abdominal aorta and the carotid artery (millimetre to centimetre size), the extent of this migration and its interaction with secondary flows has not been fully elucidated. RBC migration exerts its influence primarily on platelet concentration, oxygen transport and oxygen availability at the luminal surface, which could influence vessel wall disease processes in and adjacent to the intima. Phillips' shear-induced particle migration model, coupled to the Quemada viscosity model, was employed to simulate the macroscopic behaviour of RBCs in four patient-specific geometries: a normal abdominal aorta, an abdominal aortic aneurysm (AAA), a normal carotid bifurcation and a stenotic carotid bifurcation. Simulations show a migration of RBCs from the near-wall region with a lowering of wall haematocrit (volume fraction of RBCs) on the posterior side of the normal aorta and on the lateral-external side of the iliac arteries. A marked migration is observed on the outer wall of the carotid sinus, along the common carotid artery and in the carotid stenosis. No significant migration is observed in the AAA. The spatial and temporal patterns of wall haematocrit are correlated with the near-wall shear layer and with the secondary flows induced by the vessel curvature. In particular, secondary flows accentuate the initial lowering in RBC near-wall concentration by convecting RBCs from the inner curvature side to the outer curvature side. The results reinforce data in literature showing a decrease in oxygen partial pressure on the inner curvature wall of the carotid sinus induced by the presence of secondary flows. The lowering of wall haematocrit is postulated to induce a decrease in oxygen availability at the luminal surface through a diminished concentration of oxyhaemoglobin, hence contributing, with the reported lowered oxygen partial pressure, to local hypoxia. PMID:24850907

Biasetti, Jacopo; Spazzini, Pier Giorgio; Hedin, Ulf; Gasser, T Christian

2014-08-01

43

Effect of cetyltrimethylammonium bromide on the migration of polyaromatic hydrocarbons in capillary electrokinetic chromatography  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The separation of different ring numbered polyaromatic hydrocarbons (PAHs) was accomplished by using cetyltrimethylammonium bromide (CTAB) in capillary electrokinetic chromatography. In order to increase the solubilities and selectivities of PAHs, acetonitrile (ACN) was used as an organic modifier. Under the optimised conditions, 11 aromatic compounds were separated within 14.5 min in a running electrolyte containing 10 mM phosphate, 30 mM CTAB, and 40% ACN at pH 6.0. The effects of CTAB and ...

Kavran Belin, Gamze; Erim, F. B.; Gulacar, Fazil

2006-01-01

44

Fungal pericarditis and endocarditis secondary to porcupine quill migration in a dog.  

Science.gov (United States)

A dog evaluated for acute onset of neurologic clinical signs was discovered to have a porcupine quill traversing the left atrium with fungal endocarditis. The dog had been quilled by a porcupine one month prior to presentation and had had several quills removed from the thoracic inlet and left dorsal shoulder areas. A new murmur was identified during the initial examination. Echocardiographic changes consistent with mitral valve endocarditis were identified, in addition to a linear, hyperechoic structure in the left atrium. A thoracic CT identified a possible mediastinal migrating foreign body tract. The foreign body was surgically removed and confirmed as a porcupine quill. Routine aerobic cultures of blood and pericardial samples resulted in growth of presumptive candidal organisms. PCR amplification and sequencing of samples from pericardial cultures identified the presence of a fungal organism, Lodderomyces elongisporus. The neurologic signs were attributed to a left-sided central vestibular lesion presumed secondary to an embolic event from infective endocarditis. After 3 months of antimicrobial and antifungal therapy the valvular changes had markedly improved and the clinical signs resolved. To the authors' knowledge, this is the first description of fungal endocarditis secondary to an intracardiac foreign body in a dog. PMID:25465340

Costa, Ana; Lahmers, Sunshine; Barry, Sabrina L; Stanton, James; Stern, Joshua A

2014-12-01

45

Information content of geochemical indicators of the migration direction of hydrocarbons and its quantitative evaluation  

Energy Technology Data Exchange (ETDEWEB)

The effect of factors which accompany the process of retrograde evaportion of petroleum and compressed gases on the value of different geochemical indicators which are used as criteria of the direction of carbonaceous material migration is indicated. A method of quantitative evaluation of lateral and vertical movement of liquid and gas-like carbonaceous material in gas-condensate deposits is proposed.

Kushnirov, V.V.

1981-01-01

46

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

Energy Technology Data Exchange (ETDEWEB)

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.

Catherine L. Hanks

2008-12-31

47

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

Directory of Open Access Journals (Sweden)

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.

Larter Steve

2000-10-01

48

Stable carbon isotopic fractionation of individual n-alkanes accompanying primary migration: Evidence from hydrocarbon generation-expulsion simulations of selected terrestrial source rocks  

Energy Technology Data Exchange (ETDEWEB)

The effect of isotopic fractionation during primary migration of hydrocarbons from coals is rarely noticed because it overlaps with the isotopic effects of maturation. In this research, geological chromatography-like effects and possible physical isotopic fractionation effects on n-alkanes during primary migration from four coals and one mudstone were studied through two types of generation-expulsion simulations (generation-expulsion simulations I and II). In order to monitor the kinetic isotopic fractionation effect during primary migration and to differentiate the isotopic effects of primary migration from the isotopic effects of maturation, generation-expulsion simulation was upgraded in two aspects, source rock was separated into at least five layers, and deuterated n-C{sub 15}D{sub 32} was added to the initial layer of the source rock (simulation II). The experimental results suggested that all terrestrial source rocks exhibit significant geological chromatography-like effects in generation-expulsion simulation. Expulsion efficiencies shown by vitrinite-rich coals are much lower than algal cannel, fusinite-rich coal and mudstone. There also exist significant physical isotopic fractionation effects in hydrocarbon primary migration processes from vitrinite-rich coals, but there is no significant isotopic fractionation effect from fusinite-rich brown coal and mudstone. Pore structure and specific surface area of source rock samples were measured by gas adsorption of both N{sub 2} and CO{sub 2}. This indicated that vitrinite-rich coals have a higher proportion of microporosity. The differences in pore structure and adsorptive capacity of source rocks may be responsible for differences in expulsion efficiencies and isotopic fractionation effects in generation-expulsion simulations. The isotopic fractionation effect due to primary migration should be considered in making oil-source correlation when vitrinite-rich coals are concerned.

Liao Yuhong [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Wushan, Guangzhou 510640 (China); Geng Ansong, E-mail: asgeng@gzb.ac.cn [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Wushan, Guangzhou 510640 (China)

2009-11-15

49

Stable carbon isotopic fractionation of individual n-alkanes accompanying primary migration: Evidence from hydrocarbon generation-expulsion simulations of selected terrestrial source rocks  

International Nuclear Information System (INIS)

The effect of isotopic fractionation during primary migration of hydrocarbons from coals is rarely noticed because it overlaps with the isotopic effects of maturation. In this research, geological chromatography-like effects and possible physical isotopic fractionation effects on n-alkanes during primary migration from four coals and one mudstone were studied through two types of generation-expulsion simulations (generation-expulsion simulations I and II). In order to monitor the kinetic isotopic fractionation effect during primary migration and to differentiate the isotopic effects of primary migration from the isotopic effects of maturation, generation-expulsion simulation was upgraded in two aspects, source rock was separated into at least five layers, and deuterated n-C15D32 was added to the initial layer of the source rock (simulation II). The experimental results suggested that all terrestrial source rocks exhibit significant geological chromatography-like effects in generation-expulsion simulation. Expulsion efficiencies shown by vitrinite-rich coals are much lower than algal cannel, fusinite-rich coal and mudstone. There also exist significant physical isotopic fractionation effects in hydrocarbon primary migration processes from vitrinite-rich coals, but there is no significant isotopic fractionation effect from fusinite-rich brown coal and mudstone. Pore structure and specific surface area of source rock samples were measured by gas adsurce rock samples were measured by gas adsorption of both N2 and CO2. This indicated that vitrinite-rich coals have a higher proportion of microporosity. The differences in pore structure and adsorptive capacity of source rocks may be responsible for differences in expulsion efficiencies and isotopic fractionation effects in generation-expulsion simulations. The isotopic fractionation effect due to primary migration should be considered in making oil-source correlation when vitrinite-rich coals are concerned.

50

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)

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.

Chenet P. Y.

2006-11-01

51

Influence of Aerosol Acidity on the Formation of Secondary Organic Aerosol from Biogenic Precursor Hydrocarbons  

Science.gov (United States)

Secondary organic aerosol (SOA) formation and dynamics may be important factors for the role of aerosols in adverse health effects, visibility and climate change. Formation of SOA occurs when a parent volatile organic compound is oxidized to create products that form in a conden...

52

Optical properties of secondary organic aerosols generated by photooxidation of aromatic hydrocarbons  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The refractive index (RI) is the fundamental characteristic that affects the optical properties of aerosols, which could be some of the most important factors influencing direct radiative forcing. The secondary organic aerosols (SOAs) generated by the photooxidation of benzene, toluene, ethylbenzene and m-xylene (BTEX) under low-NOx and high-NOx conditions are explored in this study. The particles generated in our experiments are considered to be spherical, based on atomic force microscopy (A...

Kun Li; Weigang Wang; Maofa Ge; Jiangjun Li; Dong Wang

2014-01-01

53

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

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

2007-01-01

54

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

2013-04-01

55

Atlantoaxial epidural abscess secondary to grass awn migration in a dog.  

Science.gov (United States)

A two-year-old female Lucerne Hound was presented with a one-week history of signs of progressive neck pain, inappetence, apathy, and an elevated rectal temperature. Findings of magnetic resonance imaging (MRI) were consistent with a foreign body abscess in the epidural space at the level of the first and second cervical vertebrae. A left-sided dorso-lateral atlantoaxial approach was performed, revealing an epidural abscess containing a grass awn. The clinical signs resolved within three days of surgery and the dog made a full recovery. This case report shows that grass awns can migrate to the atlantoaxial region in dogs and MRI findings lead to a suspicion of caudo-cranial migration within the spinal canal. PMID:24493255

Linon, E; Geissbühler, U; Karli, P; Forterre, F

2014-01-01

56

Secondary organic aerosol formation and organic nitrate yield from NO3 oxidation of biogenic hydrocarbons.  

Science.gov (United States)

The secondary organic aerosol (SOA) mass yields from NO3 oxidation of a series of biogenic volatile organic compounds (BVOCs), consisting of five monoterpenes and one sesquiterpene (?-pinene, ?-pinene, ?-3-carene, limonene, sabinene, and ?-caryophyllene), were investigated in a series of continuous flow experiments in a 10 m(3) indoor Teflon chamber. By making in situ measurements of the nitrate radical and employing a kinetics box model, we generate time-dependent yield curves as a function of reacted BVOC. SOA yields varied dramatically among the different BVOCs, from zero for ?-pinene to 38-65% for ?-3-carene and 86% for ?-caryophyllene at mass loading of 10 ?g m(-3), suggesting that model mechanisms that treat all NO3 + monoterpene reactions equally will lead to errors in predicted SOA depending on each location's mix of BVOC emissions. In most cases, organonitrate is a dominant component of the aerosol produced, but in the case of ?-pinene, little organonitrate and no aerosol is formed. PMID:25229208

Fry, Juliane L; Draper, Danielle C; Barsanti, Kelley C; Smith, James N; Ortega, John; Winkler, Paul M; Lawler, Michael J; Brown, Steven S; Edwards, Peter M; Cohen, Ronald C; Lee, Lance

2014-10-21

57

Optical properties of secondary organic aerosols generated by photooxidation of aromatic hydrocarbons  

Science.gov (United States)

The refractive index (RI) is the fundamental characteristic that affects the optical properties of aerosols, which could be some of the most important factors influencing direct radiative forcing. The secondary organic aerosols (SOAs) generated by the photooxidation of benzene, toluene, ethylbenzene and m-xylene (BTEX) under low-NOx and high-NOx conditions are explored in this study. The particles generated in our experiments are considered to be spherical, based on atomic force microscopy (AFM) images, and nonabsorbent at a wavelength of 532?nm, as determined by ultraviolet-visible light (UV-Vis) spectroscopy. The retrieved RIs at 532?nm for the SOAs range from 1.38–1.59, depending on several factors, such as different precursors and NOx levels. The RIs of the SOAs are altered differently as the NOx concentration increases as follows: the RIs of the SOAs derived from benzene and toluene increase, whereas those of the SOAs derived from ethylbenzene and m-xylene decrease. Finally, by comparing the experimental data with the model values, we demonstrate that the models likely overestimate the RI values of the SOA particles to a certain extent, which in turn overestimates the global direct radiative forcing of the organic particles. PMID:24815734

Li, Kun; Wang, Weigang; Ge, Maofa; Li, Jiangjun; Wang, Dong

2014-01-01

58

Impact of the hydrocarbon to NOx ratio on secondary organic aerosol formation.  

Science.gov (United States)

A series of m-xylene/NOx experiments were conducted in the new Bourns College of Engineering-Center for Environmental Research and Technology dual 90 m3 indoor smog chamber to elucidate the role of NOx on the secondary organic aerosol (SOA) formation potential of m-xylene. The results presented herein demonstrate a clear dependence of m-xylene SOA formation potential on NOx, particularly at atmospherically relevant organic aerosol concentration. Experiments with lower NOx levels generated considerably more organic aerosol mass than did experiments with higher NOx levels when reacted m-xylene was held constant. For example, SOA formation from approximately 150 microg m(-3) reacted m-xylene produced 0.6-9.3 microg m(-3) aerosol mass for NOx concentrations ranging from 286 to 10 ppb. The increase in SOA formation was not attributable to changes in ozone and nitrate concentration. A general discussion about possible influences of NOx on SOA formation for this system is included. PMID:15926564

Song, Chen; Na, Kwangsam; Cocker, David R

2005-05-01

59

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

Directory of Open Access Journals (Sweden)

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.

D. K. Henze

2007-10-01

60

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

Directory of Open Access Journals (Sweden)

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.

D. K. Henze

2008-05-01

 
 
 
 
61

Phylogeographic history of the land snail Candidula unifasciata (Helicellinae, Stylommatophora): fragmentation, corridor migration, and secondary contact.  

Science.gov (United States)

We studied sequence variation in 16S rDNA in 204 individuals from 37 populations of the land snail Candidula unifasciata (Poiret 1801) across the core species range in France, Switzerland, and Germany. Phylogeographic, nested clade, and coalescence analyses were used to elucidate the species evolutionary history. The study revealed the presence of two major evolutionary lineages that evolved in separate refuges in southeast France as result of previous fragmentation during the Pleistocene. Applying a recent extension of the nested clade analysis (Templeton 2001), we inferred that range expansions along river valleys in independent corridors to the north led eventually to a secondary contact zone of the major clades around the Geneva Basin. There is evidence supporting the idea that the formation of the secondary contact zone and the colonization of Germany might be postglacial events. The phylogeographic history inferred for C. unifasciata differs from general biogeographic patterns of postglacial colonization previously identified for other taxa, and it might represent a common model for species with restricted dispersal. PMID:12389722

Pfenninger, Markus; Posada, David

2002-09-01

62

Geochemistry of oils and hydrocarbon source rocks, greater Anadarko Basin: evidence for multiple sources of oils and long-distance oil migration  

Science.gov (United States)

Organic geochemical analyses of 104 crude oils and 190 core samples of dark-colored shales from the greater Anadarko basin show three major oil types which generally correlate with reservoir age and source-rock age. Analyses include C3-C30 whole-oil gas chromatography, C10+ saturated-hydrocarbon-fraction gas chromatography, and carbon stable isotopes (ppt relative to PDB) of saturated (sat) and aromatic (arom) hydrocarbon fractions. Three samples from Middle Ordovician Simpson Group reservoirs are "typical" Ordovician oils (type 1), having strong odd-carbon predominance in the C13 to C19 n-alkanes, containing little or no acyclic isoprenoids, an ?13C values of -33.9 ppt (sat) and -33.7 ppt (arom). Oils from Silurian to Devonian and Mississippian reservoirs (type 2) show little or no odd-carbon predominance in the n-alkanes, a regular decrease in abundance of n-alkanes with increasing carbon number, pristane/phytane ratios (pr/ph) of 1.1 to 1.5, and ?13C values of -30.6 ppt (sat) and -30.1 ppt (arom). Oils in Pennsylvanian reservoirs (type 3) have the greatest amounts of C15+ hydrocarbons, are isotopically heavy (-27.5 ppt [sat] and -26.4 ppt [arom]), have methyl-cyclohexane as the most abundant hydrocarbon, and have pr/ph values from 2.0 to 0.9. Oils from the Kansas shelf area of the Anadarko basin are similar to the Anadarko oil types except that they have only traces of toluene and no detectable benzene. The relative abundance of toluene in the C7 hydrocarbons systematically decreases with distance from the depocenter of the basin. The aromatic compounds are removed by water-washing, and hence could have been lost by contact with progressively greater amounts of formation water during long-distance migration. The lack of thermally mature source rocks in southern and central Kansas supports this hypothesis.

Burruss, R.C.; Hatch, J.R.

1989-01-01

63

Malfunción valvular intermitente por migración del catéter peritoneal a escroto / Shunt dysfunction secondary to peritoneal catheter migration to the scrotum  

Scientific Electronic Library Online (English)

Full Text Available SciELO Argentina | Language: Spanish Abstract in spanish Introducción. La malfunción valvular por obstrucción del catéter proximal es un hecho relativamente frecuente en el servicio de urgencias de los grandes hospitales, pero la obstrucción distal de causa no infecciosa es excepcional. Caso clínico. Presentamos un varón de 6 años con malfunción valvular [...] aguda, por migración del catéter distal al hemiescroto derecho. Para resolver el cuadro completamente se realizó un cierre del conducto peritoneo-vaginal de urgencia. Discusión. La permeabilidad del conducto peritoneo-vaginal (existente en hasta el 60% de los varones menores de 1 año) es la causante de los hidroceles en los pacientes portadores de una derivación ventrículo-peritoneal. Pero la migración del catéter es muy infrecuente, sobre todo en mayores de un año. Si este hecho conlleva el aumento de la presión intracraneal con disfunción valvular, el cierre de urgencia de dicho conducto debe ser prioritario. Abstract in english Introduction. Valvular dysfunction secondary to obstruction of proximal catheter is relatively frequent at emergency room. However non-infectius obstruction of distal catheter is exceptional. Case report. A 6-year-old boy with dysfunction shunt due to migration of the abdominal catheter into the rig [...] ht scrotum. The patient was operated urgently for peritoneum-vaginal processus closure. Discussion. Permeability of the peritoneum-vaginal processus (until 60% of boys younger than one year) causes hydrocele in patients with ventricle-peritoneal shunt. However migration of the peritoneal cateter is very infrequent specially in patients older than one year. In the case of this event with increased intracraneal pressure levels and shunt malfunction, emergency closure of the duct should be a priority.

Mónica, Rivero-Garvía; José Luis, Barbeito Gaído; Juan, Morcillo; Javier, Márquez Rivas.

2013-02-01

64

Secondary uranium mineralization in Southern Fennoscandia - Migration and retention in granitic rock  

International Nuclear Information System (INIS)

The geochemical cycling of natural radioactive elements in the Fennoscandian Shield is of great relevance to the Finnish nuclear waste disposal programme. It indicates the likely fate of nuclides released from a repository and provides essential information on the palaeohydrogeological evolution of the region in response to climate change. For these and other reasons, comparison of predicted releases with natural radioactive fluxes is enshrined in the legislation. Glacial advance and retreat are thought to constitute the greatest natural threats to the integrity of a repository situated in the Finnish bedrock. Several major glaciations have affected northern Europe in the last million years; post-glacial uplift following the most recent ice retreat is still significant. Studies of fracture mineralogy furnish important data regarding the timing of climatic events and, among these, secondary uranium minerals play a key role. New results obtained from the natural uranium deposits at Palmottu and Hyrkkoelae are described in this report and used to supplement existing data on the geochemical and hydrogeological evolution of the region. In parallel with the above, the Finnish regulator, STUK, is assessing the feasibility of applying a coupled chemical transport model in simulations of radionuclide transport from the proposed repository. Sufficient evidence has now been gained to allow a credible test of such a model at either Olkiluoto or a surrogate study site. (orig.)oto or a surrogate study site. (orig.)

65

Aryl hydrocarbon receptor antagonism attenuates growth factor expression, proliferation, and migration in fibroblast-like synoviocytes from patients with rheumatoid arthritis.  

Science.gov (United States)

Rheumatoid arthritis (RA) is a chronic autoimmune disease with high morbidity and mortality. Within the inflammatory milieu, resident fibroblast-like synoviocytes (FLS) in the synovial tissue undergo hyperplasia, which leads to joint destruction. Epidemiologic studies and our previous research suggest that activation of the aryl hydrocarbon receptor (AHR) pathway plays an instrumental role in the inflammatory and destructive RA phenotype. In addition, our recent studies implicate the AHR in the regulation of the expression of several growth factors in established tumor cell lines. Thus, under inflammatory conditions, we hypothesized that the AHR is involved in the constitutive and inducible expression of several growth factors, FLS proliferation and migration, along with protease-dependent invasion in FLS from patients with RA (RA-FLS). Treatment with the AHR antagonist GNF351 inhibits cytokine-induced expression of vascular endothelial growth factor-A (VEGF-A), epiregulin, amphiregulin, and basic fibroblast growth factor mRNA through an AHR-dependent mechanism in both RA-FLS and FLS. Secretion of VEGF-A and epiregulin from RA-FLS was also inhibited upon GNF351 treatment. RA-FLS cell migration, along with cytokine-induced RA-FLS cell proliferation, was significantly attenuated by GNF351 exposure. Treatment of RA-FLS with GNF351 mitigated cytokine-mediated expression of matrix metalloproteinase-2 and -9 mRNA and diminished the RA-FLS invasive phenotype. These findings indicate that inhibition of AHR activity may be a viable therapeutic target in amelioration of disease progression in RA by attenuating growth factor release; FLS proliferation, migration, and invasion; and inflammatory activity. PMID:24309559

Lahoti, Tejas S; Hughes, Jarod M; Kusnadi, Ann; John, Kaarthik; Zhu, Bokai; Murray, Iain A; Gowda, Krishne; Peters, Jeffrey M; Amin, Shantu G; Perdew, Gary H

2014-02-01

66

The Feminisation of Migration and the Migrants VET Policy Neglects: The Case of Skilled Women Secondary Migrants in Australia  

Science.gov (United States)

There is increasingly scholarship on gender and migration, yet the international migration of highly skilled women is still somewhat under-researched. This article focuses on this neglected area in the context of Australia's discretionary inward migration policies to solve skills shortages. The article draws on empirical research using a…

Webb, Sue

2015-01-01

67

Microbial Oxidation of Gaseous Hydrocarbons: Production of Secondary Alcohols from Corresponding n-Alkanes by Methane-Utilizing Bacteria  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Over 20 new strains of methane-utilizing bacteria were isolated from lake water and soil samples. Cell suspensions of these and of other known strains of methane-utilizing bacteria oxidized n-alkanes (propane, butane, pentane, hexane) to their corresponding secondary alcohols (2-propanol, 2-butanol, 2-pentanol, 2-hexanol). The product secondary alcohols accumulated extracellularly. The rate of production of secondary alcohols varied with the organism used for oxidation. The average rate of 2-...

Patel, Ramesh N.; Hou, C. T.; Laskin, A. I.; Felix, A.; Derelanko, P.

1980-01-01

68

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

Science.gov (United States)

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.

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

2007-12-01

69

SECONDARY ORGANIC AEROSOL FORMATION FROM THE OXIDATION OF AROMATIC HYDROCARBONS IN THE PRESENCE OF DRY SUBMICRON AMMONIUM SULFATE AEROSOL  

Science.gov (United States)

A laboratory study was conducted to examine formation of secondary organic aerosols. A smog chamber system was developed for studying gas-aerosol interactions in a dynamic flow reactor. These experiments were conducted to investigate the fate of gas and aerosol phase compounds ...

70

Migration of residual contaminants from secondary recycled poly(ethylene terephthalate) into food-simulating solvents, aqueous ethanol and heptane.  

Science.gov (United States)

This study measured the migration of benzene, butyric acid, dodecane, octadecane, tetracosane, diazinon, lindane, and copper (II) ethyl hexonate from poly(ethylene terephthalate)(PETE) sheets into the food simulants, 8% ethanol/water and n-heptane. The contaminated PETE sheets were extruded from PETE chips that had been previously contaminated but were washed, dried, and remelted. The level of these contaminants remaining in the extruded sheets ranged from benzene at 0.6 mg/kg to copper salt at 24 mg/kg. The extraction data demonstrate that migration of the residual contaminants from the extruded PETE sheets resulted in concentrations lower than 10 micrograms/kg in the food simulants. At very high residual concentrations of butryic acid (147 mg/kg) and benzene (218 mg/kg) in sheets made from unwashed PETE, higher amounts of the contaminant migrated into the food simulants. This migration resulted in contaminant concentrations exceeding 10 micrograms/kg and suggests that unwashed recycled PETE may not comply with FDA requirements. The crystallinity of extruded PETE sheets in this study ranged from 5 to 15%, which is lower than that of most commercial PETE (30%). Therefore, the migration data obtained from these test samples represent the most severe conditions for conservative exposure evaluations. PMID:9328534

Komolprasert, V; Lawson, A R; Begley, T H

1997-07-01

71

Laboratory demonstration of hydrocarbon migration in the vadose zone: Effectiveness of the U-tube design for underground storage tank leak detection monitoring  

International Nuclear Information System (INIS)

The experimental results derived from a laboratory model of gasoline migration from a simulated leaking underground storage tank (UST) demonstrate that the direction of migration through the simulated fill material is essentially straight down. Consequently,, the U-tube design for leak detection monitoring of USTs has limited utility because that design relies on the assumption that the path of migration of the leaked fluids will follow the surface of the tank to the bottom and be intercepted by the U-tube below

72

Hydrothermal dolomitization in the Lower Ordovician Romaine Formation of the Anticosti Basin : significance for hydrocarbon exploration  

Energy Technology Data Exchange (ETDEWEB)

Hydrothermal dolomitization refers to dolomitization by fluids characterized by higher fluid temperatures than those of the ambient burial environment. Hydrothermal dolomite hydrocarbon reservoirs are among the most important exploration targets in the world. This paper presented the results of a study in which the diagenetic evolution of dolostones from the Romaine Formation were examined. Cores and outcrops on Anticosti and Mingan Islands have shown evidence for hydrocarbon migration in secondary porosity generated by hydrothermal alteration. The Ordovician succession on Anticosti Island has shown late hydrocarbon migration and multiple events of dolomitization of the Lower Ordovician Romaine Formation. A late hydrothermal event was responsible for high porosities. Portions of fractures in zones with low permeabilities were filled with a later hydrocarbon inclusion-rich calcite. The dolomitization events for the open marine limestones of the Middle-Upper Ordovician Mingan Formation were documented. Three dolomitization events have been recorded for the open marine limestones of the Middle-Upper Ordovician Mingan Formation. Four types of calcite and 6 types of dolomite have been distinguished. Brecciation of a precursor dolomite host has been recognized in the hydrothermal dolomite hydrocarbon fields. This type of alteration in the Ordovician carbonates along with rich hydrocarbon source rocks are key drivers for continued exploration activities in the basin. 74 refs., 2 tabs., 8 figs.

Lavoie, D.; Chi, G. [Natural Resources Canada, Quebec, PQ (Canada). Geological Survey of Canada, Quebec Division; Brennan-Alpert, P.; Desrochers, A. [Ottawa Univ., ON (Canada). Dept. of Earth Sciences; Bertrand, R. [Quebec Univ., Quebec, PQ (Canada). Institut National de la Recherche Scientifique-Eau, Terre et Environnement

2005-12-15

73

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)

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.

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

74

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

75

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

Science.gov (United States)

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.

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

2012-03-01

76

Litiasis vesical secundaria a migración de dispositivo intrauterino: Reporte de un caso / Bladder lithiasis secondary to intrauterine device migration: Case report  

Scientific Electronic Library Online (English)

Full Text Available SciELO Spain | Language: Spanish Abstract in spanish Objetivo: Presentar un caso clínico de litiasis vesical secundaria a la migración de un dispositivo intrauterino, su sintomatología, los medios empleados para su diagnóstico y el tratamiento aplicado. Método/Resultado. Paciente de 30 años de edad, que al cabo del año de colocársele un dispositivo in [...] trauterino (T de cobre), luego de interrupción de embarazo mediante legrado endometrial, comenzó a presentar síntomas urinarios irritativos bajos. Se le trató durante dos años como si tuviese cistitis infecciosa con varios ciclos de diferentes antibióticos. Por la persistencia de las molestias asiste a la consulta de Urología, y se le detecta, mediante ultrasonido y radiografía ántero-posterior de la pelvis, una litiasis intravesical de cinco por tres centímetros de tamaño, con una T de cobre en su interior. Se le realizó la cistolitotomía suprapúbica, presentando una buena evolución y regresión total de los síntomas. Conclusión. La migración de un dispositivo intrauterino a la vejiga, es una causa infrecuente de litiasis vesical secundaria a cuerpo extraño. No obstante, debemos pensar en esta posibilidad ante la cronicidad de síntomas urinarios irritativos bajos, en toda mujer que emplee este método anticonceptivo. Abstract in english Objective: To report one clinical case of bladder lithiasis secondary to the migration of an intrauterine device, its symptoms, diagnostic tests employed and treatment. Methods/Results: 30 year old female patient who presented lower urinary tract irritative symptoms. One year before she underwent in [...] sertion of an intrauterine device (copper T) after endometrial curettage for pregnancy interruption. She received treatment for infection cystitis over two years, with various antibiotic cycles. The persistence of symptoms led her to the urology clinics, and a 5x 3 cm intravesical lithiasis with a copper T inside was detected by ultrasound and pelvic anterior-posterior x-ray. Suprapubic cystolithotomy was performed with a good outcome and disappearance of the symptoms. Conclusions: The migration of an intrauterine device to the bladder is an unfrequent cause of bladder lithiasis secondary to foreign body. Nevertheless, we must consider this possibility in front of chronic lower urinary tract irritative symptoms in every female using this birth control method.

Tomás Lázaro, Rodríguez Collar; Yamel, Gil del Valle; Basily, Valdés Estévez; Víctor Osvaldo, Barquín Carmona; José Antonio, García Monzón.

2008-06-01

77

The presence of hydrocarbons in southeast Norway  

DEFF Research Database (Denmark)

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.

Hanken, Niels Martin; Hansen, Malene Dolberg

78

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)

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)

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

79

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

Science.gov (United States)

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

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

2015-01-01

80

An open-water electrical geophysical tool for mapping sub-seafloor heavy placer minerals in 3D and migrating hydrocarbon plumes in 4D  

Science.gov (United States)

A towed-streamer technology has been developed for mapping placer heavy minerals and dispersed hydrocarbon plumes in the open ocean. The approach uses induced polarization (IP), an electrical measurement that encompasses several different surface-reactive capacitive and electrochemical phenomena, and thus is ideally suited for mapping dispersed or disseminated targets. The application is operated at sea by towing active electrical geophysical streamers behind a ship; a wide area can be covered in three dimensions by folding tow-paths over each other in lawn-mower fashion. This technology has already been proven in laboratory and ocean settings to detect IP-reactive titanium-and rare-earth (REE) minerals such as ilmenite and monazite. By extension, minerals that weather and accumulate/concentrate by a similar mechanism, including gold, platinum, and diamonds, may be rapidly detected and mapped indirectly even when dispersed and covered with thick, inert sediment. IP is also highly reactive to metal structures such as pipelines and cables. ?? 2011 MTS.

Wynn, J.; Williamson, M.; Urquhart, S.; Fleming, J.

2011-01-01

 
 
 
 
81

Control and assessment of the hydrocarbon contamination of Ukrainian soils  

Science.gov (United States)

Regularities governing the self-purification of soils from oil hydrocarbons, as well as migration of hydrocarbons, and the effect on the water-physical properties and fertility of soils were revealed in a series of experiments. A system of ecological, economic, and reclamation standards was proposed for regulating economic activities in the case of soil contamination with hydrocarbons.

Miroshnichenko, N. N.

2008-05-01

82

Petroleum hydrocarbons  

International Nuclear Information System (INIS)

Methods for analysis of petroleum hydrocarbons in marine samples are presented. Types of hydrocarbons present and their origins are discussed. Principles and methods of analysis are outlined. Infrared spectrometry, uv spectrometry, gas chromatography, mass spectroscopy, and carbon 14 measurements are described

83

Hydrocarbon Transport  

Science.gov (United States)

... conducted using a "constant-head groundwater flow chamber" and natural soil. Freezing fronts were ... pads' placed on the surface of the soil. Slug inputs of various contaminants, including hydrocarbons ...

84

Development of a supercritical fluid extraction-gas chromatography-mass spectrometry method for the identification of highly polar compounds in secondary organic aerosols formed from biogenic hydrocarbons in smog chamber experiments  

Energy Technology Data Exchange (ETDEWEB)

A new one-step method for the analysis of highly polar components of secondary organic aerosols (SOA) has been developed. This method should lead to a better understanding of SOA formation and evolution since it enables the compounds responsible for SOA formation to be identified. Since it is based on supercritical fluid extraction coupled to gas chromatography-mass spectrometry, it minimizes the analysis time and significantly enhances sensitivity, which makes it suitable for trace-level compounds, which are constituents of SOA. One of the key features of this method is the in situ derivatisation step: an online silylation allowing the measurement of highly polar, polyfunctional compounds, which is a prerequisite for the elucidation of chemical mechanisms. This paper presents the development of this analytical method and highlights its ability to address this major atmospheric issue through the analysis of SOA formed from the ozonolysis of a biogenic hydrocarbon (sabinene). Ozonolysis of sabinene was performed in a 6 m{sup 3} Teflon chamber. The aerosol components were derivatised in situ. More than thirty products, such as sabinaketone, sabinic acid and other multifunctional compounds including dicarboxylic acids and oxoacids, were measured. Nine of them were identified and quantified. The sensitivity and the linearity (0.91 < R < 0.98) of the method were both good and detection limits ranged from 1.2 to 6.4 ng for the investigated compounds. (orig.)

Chiappini, L.; Perraudin, E.; Durand-Jolibois, R.; Doussin, J.F. [Universites Paris, Laboratoire Interuniversitaire des Systemes Atmospheriques, UMR CNRS 7583, Creteil (France)

2006-11-15

85

Development of a supercritical fluid extraction-gas chromatography-mass spectrometry method for the identification of highly polar compounds in secondary organic aerosols formed from biogenic hydrocarbons in smog chamber experiments.  

Science.gov (United States)

A new one-step method for the analysis of highly polar components of secondary organic aerosols (SOA) has been developed. This method should lead to a better understanding of SOA formation and evolution since it enables the compounds responsible for SOA formation to be identified. Since it is based on supercritical fluid extraction coupled to gas chromatography-mass spectrometry, it minimizes the analysis time and significantly enhances sensitivity, which makes it suitable for trace-level compounds, which are constituents of SOA. One of the key features of this method is the in situ derivatisation step: an online silylation allowing the measurement of highly polar, polyfunctional compounds, which is a prerequisite for the elucidation of chemical mechanisms. This paper presents the development of this analytical method and highlights its ability to address this major atmospheric issue through the analysis of SOA formed from the ozonolysis of a biogenic hydrocarbon (sabinene). Ozonolysis of sabinene was performed in a 6 m3 Teflon chamber. The aerosol components were derivatised in situ. More than thirty products, such as sabinaketone, sabinic acid and other multifunctional compounds including dicarboxylic acids and oxoacids, were measured. Nine of them were identified and quantified. The sensitivity and the linearity (0.91

Chiappini, L; Perraudin, E; Durand-Jolibois, R; Doussin, J F

2006-11-01

86

Transport of petroleum hydrocarbons in permafrost soils  

International Nuclear Information System (INIS)

A sampling program was conducted to determine the presence and extent of petroleum hydrocarbon contamination in permafrost soils at an abandoned arctic weather station. Core samples were taken of frozen silty clay at two known contaminated sites and analyzed for total petroleum hydrocarbon content. Contamination was observed at depths of 0.5 m into the permafrost. The most influential transport mechanism is likely to be migration of hydrocarbons through cracks, fissures and filled voids in the permafrost soil due to gravity drainage and capillary action. Another possible transport mechanism is by diffusion in unfrozen water within the permafrost. 19 refs., 4 figs

87

High-temperature dolomites in the Ordovician section of Anticosti Island, Eastern Canada : implications for hydrocarbon reservoirs development  

Energy Technology Data Exchange (ETDEWEB)

The hydrocarbon reservoirs in the Ordovician carbonates along the continental margin of Laurentia were formed by dolomitization caused by circulating hydrothermal fluids. A study of the Ordovician succession on Anticosti Island has shown late hydrocarbon migration and multiple events of dolomitization at the peritidal facies of the Lower Ordovician Romaine Formation. A late hydrothermal event was responsible for high porosities resulting from highly saline fluids (24 wt per cent NaCl). Portions of fractures in zones with low permeabilities were filled with a later hydrocarbon inclusion-rich calcite. Three dolomitization events are recorded for the open marine limestones of the Middle-Upper Ordovician Mingan Formation. Dolomite replacement was observed only in pore-filling calcite. The latest dolomite replacement occurred under high temperature conditions with highly saline fluid inclusions. The hydrothermal fluids were circulated in the Romaine aquifer and breached into the Mingan at the edge of the Lower Ordovician platform in northern Anticosti. The Middle-Upper Ordovician Mingan Formation was altered by the fluids circulating along major extensional faults. Gas shows from the Mingan interval in southern Anticosti wells suggest that the fluids grew colder as the migrated upwards, generating secondary porosity.

Lavoie, D. [Geological Survey of Canada - Quebec Division, Ste-Foy, PQ (Canada); Chi, G. [Regina Univ., SK (Canada)

2003-07-01

88

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)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese 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.

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

2014-09-01

89

The hydrocarbon sphere  

Energy Technology Data Exchange (ETDEWEB)

The hydrocarbon sphere is understood to be the area in which hydrocarbon compounds are available. It is believed that the lower boundary on the hydrocarbon sphere is most probably located at a depth where the predominant temperatures aid in the destruction of hydrocarbons (300 to 400 degrees centigrade). The upper limit on the hydrocarbon sphere obviously occurs at the earth's surface, where hydrocarbons oxidize to H20 and CO2. Within these ranges, the occurrence of the hydrocarbon sphere may vary from the first few hundred meters to 15 kilometers or more. The hydrocarbon sphere is divided into the external (mantle) sphere in which the primary gas, oil and solid hydrocarbon fields are located, and the internal (metamorphic) sphere containing primarily noncommercial accumulations of hydrocarbon gases and solid carbon containing compounds (anthraxilite, shungite, graphite, etc.) based on the nature and scale of hydrocarbon compound concentrations (natural gas, oil, maltha, asphalt, asphaltite, etc.).

Mandev, P.

1984-01-01

90

Petroleum hydrocarbons in detention-basin sediments  

International Nuclear Information System (INIS)

The present study was conducted to examine petroleum hydrocarbons in the sediments of a storm-water retention basin in central New Jersey. A dry storm-water detention basin, which services a 0.405-km2 condominium development, was used for the investigation. Soil samples were collected following the general pattern of water progression through the basin and analyzed for total petroleum hydrocarbons. The study found petroleum hydrocarbons, being hydrophobic in nature, sorb to particulates that settle and reside in the sediment. Results comparing two successive summer samplings show that levels of petroleum hydrocarbons are maintained in the basin sediments. General trends showed that the hydrocarbon concentrations are a function of depth and proximity to the influent culverts. One soil core was extended to a depth of 15.2 cm. The results show hydrocarbon concentrations decreasing to back ground levels at 15.2 cm. At present, however, it is not possible to determine whether or not the hydrocarbons are degraded or pose a migration threat

91

Cross-Border Migration and East Asian Regional Integration  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Against the background of profound economic and political changesin East Asia, this paper examines key trends in migration within theregion. It highlights the increasingly multidirectional nature ofmigration flows, the importance of undocumented migration, and thegrowing significance of secondary diasporas and return migration.While future large-scale flows of migration are likely, the changingnature of regional migration makes it more difficult for existinginternational frameworks to respond...

Tessa Morris Suzuki

2007-01-01

92

Tomographic imaging of residual hydrocarbon in water saturated unconsolidated sediments  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Determining the amount and distribution of residual hydrocarbon in granular media is important for monitoring secondary and tertiary recovery processes during hydrocarbon production. The distribution of residual hydrocarbon is affected by the structure of the granular media (layering, grain, pore size, etc.), and the method used to produce oil (single well, multi-well, etc.). Seismic technique are often used to monitor the recovery process, thus, it is required that the effect of structure an...

Li, Xun

2002-01-01

93

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.)

94

Remote Sensing And Surface Hydrocarbon Leakage  

Science.gov (United States)

The Geosat oil and gas test site program stimulated interest in the interaction between surface hydrocarbon concentrations and interpretation of remote sensing data. The test case results suggested that lineaments correspond to avenues of preferential hydrocarbon seepage and that this seepage affects vegetation health and populations at Patrick Draw field in Wyoming and potentially at Lost River field, West Virginia. These two areas were selected for additional surface hydrocarbon surveys in order to test these hypotheses. The Patrick Draw study shows that a zone of stressed vegetation, visible on thematic mapper data, definitely coincides with an area of marked leakage of hydrocarbons and that the composition of these gases would predict an intermediate type oil and gas reservoir such as exists in the area. The study further indicates that the leakage is in large part controlled by the presence of fractures/faults recognized as lineaments on the remote sensing images. The Lost River study specifically investigated the possible existence of hydrocarbon leakage causing anomalous populations of maple trees in a climax oak forest. These maples were first recognized by study of thematic mapper simulator data. The soil gas hydrocarbon concentrations are above average in several of the maple anomalies over the field. This supports the inference that the maples are present because they are more tolerant of soil conditions where hydrocarbon seepage is active. The crest of the field has low soil gas magnitudes, but high values occur to the updip eastern edge of the field along a fault/fracture that was detected in the seismic data. The conclusion that preferential pathways of hydrocarbon leakage are recognized in spectral and textural analysis of remote sensing data is supported by other studies and integrated into a suggested exploration/hydrocarbon migration model.

Matthews, M. D.; Jones, V. T.; Richers, D. M.

1984-08-01

95

The Culture of Mexican Migration: A Theoretical and Empirical Analysis.  

Science.gov (United States)

Examines a Mexican "culture of migration," in which U.S. migration becomes an expectation for young people. Among approximately 7,000 secondary students surveyed in Zacatecas (Mexico), adolescents from families involved in U.S. migration were more likely to aspire to live and work in the United States, increasing the likelihood they would drop out…

Kandel, William; Massey, Douglas S.

2002-01-01

96

Hydrocarbon Problems & Nature Principles  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The understanding of Energy problems, Peak Oil Production Hydrocarbon Remaining Reserves, etc., is based on Nature Principles, which allow the interpretation of Hydrocarbon Data, and so, advance several petroleum conjectures.

Cramez, Carlos; Laherre?re, J.

2006-01-01

97

The Subduction Factory of Hydrocarbon Formation  

Science.gov (United States)

THE SUBDUCTION FACTORY OF HYDROCARBON FORMATION K. A. Kleschev VNIGNI, Moscow, Russia balanyuk@sio.rssi.ru In the zones of collision of continental lithospheric plates, the subducting plates drive down great amounts of sediments formed at the former passive margins. This sedimentary layer, enclosed between two plates, contains significant quantities of hydrocarbons and occurs under the effect of strong shear deformations and special thermodynamic conditions. As the mass of the sediments passing through this zone is rather great, there are favorable conditions for occurrence of numerous hydrocarbon fields of industrial importance, including fields giants. Combined consideration of geodynamic and fluidodynamic aspects in a model of lithospheric plates collision enables to understand the influence of P T conditions and shear deformations on the mechanism of hydrocarbon generation and to look after their migration in the lithosphere up to the formation of deposits. Such model would allow one not only to describe and to explain these processes, but also to predict some features essential for the search and exploration of hydrocarbon fields in these regions and their classification. Enormous volumes of sediments accumulated over continental slopes and shelves are involved into the subduction zones in the course of overthrusting of island arcs onto continental margins. The weight of the overthrusting island arc substantially accelerates the subsiding of the continental margin. Crustal ground waters and hydrocarbons, capable to migration, begin to be squeezed out from the sedimentary material delivered to the waveguide zone under the island arc. The waters from the waveguide zone and the thermal water, released through dehydration of sediments and rocks of the former ocean crust and supplied from the deeper parts of the subduction zone, favor this process. Although the major portion of hydrocarbons is discharged and lost still in the body of the island arc itself, appreciable amounts of them can migrate from beneath the arc toward the marginal parts of the continental platform, on which the island arch is moved upon, or even toward its rear zones beyond the volcanic front of the arc, permeating through rather wide passages between rather narrow volcanic channels (a characteristic example is provided by the Rocky Mountains).

Kleschev, K. A.

2003-04-01

98

Hydrocarbon Formation in Immature Sediments  

Directory of Open Access Journals (Sweden)

Full Text Available

Immature sediments (Ro=<0.6 and hydrates commonly contain low concentrations of C2-8+ alkanes/alkenes, higher alkanes, cycloalkanes and aromatics (temperature=<373 K; Pressure=<100 MPa. Their origin is enigmatic. Traditionally they are interpreted as migrated thermogenic oil. Water treatment experiments have established that they could be formed through the interaction of water and organic carbon by Fe catalysis at 298 K. This study investigates the Eh and pH associated with low temperature (263-298 K hydrocarbon formation in saline pore-waters containing Ca-montmorillonite and Fe0 (ZVI over a 300 day period in order to identify the principal reaction mechanisms. The interaction of flowing gaseous carbon dioxide-hydrocarbon mixtures with halite promoted with FexOy, Fex[OH]y at 288 – 308 K is examined experimentally. The study established that halite and mixtures of halite with organic material, Fe-montmorillonite, CaCO3, Ca(OH2, MgSO4, (NH42SO4, K2SO4, pyroclastics, ash, phosphate enriched organic material, and coal can facilitate the removal of CO2, the formation of H2O on the catalyst surface, and the formation of hydrocarbons incorporating the CO2.

Key Word: ZVI; Oil formation; CO2; Eh; pH; NaCl; Halite; Montmorillonite

D.D.J. ANTIA

2011-07-01

99

Direct radiometric dating of hydrocarbon deposits using Rhenium-Osmium isotopes.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Rhenium-osmium (Re-Os) data from migrated hydrocarbons establish the timing of petroleum emplacement for the giant oil sand deposits of Alberta, Canada, at 112 ± 5.3 million years ago. This date does not support models that invoke oil generation and migration for these deposits in the Late Cretaceous. Most Re-Os data from a variety of deposits within the giant hydrocarbon system show similar characteristics, supporting the notion of a single source for these hydrocarbons. The Re-Os data disq...

Selby, D.; Creaser, R. A.

2005-01-01

100

The tectonic evolution of western India and its impact on hydrocarbon occurrences: an overview  

Science.gov (United States)

The largest hydrocarbon accumulations of India were localized in western India by a unique convergence of tectonic events. Mesozoic rifting along the structural trends of Proterozoic mobile belts formed the passive margin basins of the Indian coast. During the Campanian rifting of Madagascar from India, north-south-striking normal faults propagated into the area of the Cambay Graben. Late Maastrichtian doming over the incipient Deccan/Réunion hotspot imparted extensional stresses to the northwestern Indian coast and formed the fault block that became the Bombay High. After eruption of the Deccan flood basalts in Early Paleocene, extension continued in the weakened crust. This resulted in enhanced subsidence of the Cambay Graben and Surat (Danahu) Depression, rifting of the Seychelles microcontinent from India, and reactivation of normal faults on the emergent Bombay High. The Cambay Graben and the Surat (Danahu) Depression filled with organic-rich source shales as they underwent thermal subsidence. Shallow-water Eocene to Miocene carbonates developed on the slowly subsiding Bombay Platform, and sea-level oscillations fostered secondary porosity development. Late Tertiary maturation of the Surat (Danahu) Depression shales generated hydrocarbons that migrated into the carbonate reservoirs on the Bombay High. Konkan-Kerala, and the older basins of the east coast of India, were unaffected by the post-Campanian tectonic events, and lack the favorable play elements that characterize the giant fields.

Gombos, Andrew M.; Powell, William G.; Norton, Ian O.

1995-04-01

 
 
 
 
101

SECONDARY ORGANIC AEROSOL FORMATION FROM THE IRRADIATION OF SIMULATED AUTOMOBILE EXHAUST  

Science.gov (United States)

A laboratory study was conducted to evaluate the potential for secondary organic aerosol formation from emissions from automotive exhaust. The goal was to determine to what extent photochemical oxidation products of these hydrocarbons contribute to secondary organic aerosol (SO...

102

Ambient aromatic hydrocarbon measurements at Welgegund, South Africa  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 representati...

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

2014-01-01

103

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)

104

Hydrocarbon Reserves: Abundance or Scarcity  

Energy Technology Data Exchange (ETDEWEB)

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)

NONE

2005-07-01

105

Secondary parkinsonism  

Science.gov (United States)

Parkinsonism - secondary; Atypical Parkinson disease ... to be less responsive to medical therapy than Parkinson disease. ... Unlike Parkinson disease, secondary parkinsonism may stabilize or even improve if the underlying cause is treated. Brain problems, such ...

106

Cuticular hydrocarbons of triatomines.  

Science.gov (United States)

Triatomine insects (Hemiptera) are the vectors of Chagas disease. Their cuticular surface is covered by a thin layer of lipids, mainly hydrocarbons, wax esters, fatty alcohols, and free or esterified fatty acids. These lipids play a major role in preventing a lethal desiccation, altering the absorption of chemicals and microorganism penetration, they also participate in chemical communication events. Lipid components are biosynthetically related, the synthesis of long chain and very long chain fatty acids was first shown in the integument of Triatoma infestans through the concerted action of fatty acid synthases (FAS's) and fatty acyl-CoA elongases. A final decarboxylation step produces the corresponding hydrocarbon. Capillary gas chromatography coupled to mass spectrometry analyses showed that cuticular hydrocarbons of Triatominae comprise saturated straight and methyl-branched chains, from 18 to more than 43 carbon atoms. Odd-chain hydrocarbons, mostly from 27 to 33 carbons, are the major straight chains. Different isomers of mono, di, tri, and tetramethylcomponents, mostly from 29 to 39 atoms in the carbon skeleton, account for the major methyl-branched hydrocarbons. The presence, absence, and relative quantities of these hydrocarbons represent characters for their chemical phenotype, and are useful for differentiating genera, species and populations. In this review, we will discuss the metabolic pathways involved in hydrocarbon formation, and their structure, together with their role in insect survival. We will also review the utility of cuticular hydrocarbon fingerprints in chemotaxonomy. PMID:17046303

Juárez, M P; Fernández, G C

2007-07-01

107

Subsea hydrocarbon sensor system  

Energy Technology Data Exchange (ETDEWEB)

A hydrocarbon detection system is provided for use in a subsea hydrocarbon production installation which includes production tree assemblies, an electro-hydraulic control module located on the sea floor and remote from the production trees, cable assemblies interconnecting the control module with the production trees through magnetic coupling devices. A pair of inductive elements are electrically coupled by the surrounding sea water. Displacement of the conductive sea water by escaping hydrocarbons affects the coupling between the inductive elements to produce a hydrocarbon-presence-responsive output signal. The inductive elements are resonated within a selected frequency range by capacitors coupled with a primary inductor coil by auxiliary windings on a common core element. An excitation signal sweeps over the selected frequency range at a rate effective to produce a peak detected signal at the resonant frequency. The peak output signal is then monitored to form a control signal functionally related to the presence or absence of hydrocarbons in the sea water.

Marosko, R.J.; Warren, W.B.

1981-08-04

108

Catalytic reforming of hydrocarbons  

International Nuclear Information System (INIS)

A process is described comprising the step of contacting a hydrocarbon feed stream comprising at least one hydrocarbon selected from the group consisting of alkanes containing from 2 to 20 carbon atoms per molecule and cycloalkanes containing from 5 to 20 carbon atoms per molecule with a catalyst composition comprising (a) at least one oxide of vanadium and (b) aluminum phosphate, in the substantial absence of free oxygen, steam and sulfur compounds and under such reaction conditions as to convert at least a portion of the hydrocarbon feed stream to a product comprising hydrogen gas and at least one hydrocarbon selected from the group consisting of alkenes. The alkenes contain from 2 to 20 carbon atoms, alkadiene, containing from 4 to 20 carbon atoms, cycloalkenes containing from 5 to 20 carbon atoms, cycloalkadienes containing from 5 to 20 carbon atoms and aromatic hydrocarbons containing from 6 to 20 carbon atoms per molecule

109

Hydrocarbon provinces and productive trends in Libya and adjacent areas  

Energy Technology Data Exchange (ETDEWEB)

According to the age of major reservoirs, hydrocarbon occurrences in Libya and adjacent areas can be grouped into six major systems which, according to their geographic locations, can be classified into two major hydrocarbon provinces: (1) Sirte-Pelagian basins province, with major reservoirs ranging from middle-late Mesozoic to early Tertiary, and (2) Murzog-Ghadames basins province, with major reservoirs ranging from early Paleozoic to early Mesozoic. In the Sirte-Pelagian basins province, hydrocarbons have been trapped in structural highs or in stratigraphic wedge-out against structural highs and in carbonate buildups. Here, hydrocarbon generation is characterized by the combined effect of abundant structural relief and reservoir development in the same hydrocarbon systems of the same age, providing an excellent example of hydrocarbon traps in sedimentary basins that have undergone extensive tensional fracturing in a shallow marine environment. In the Murzog-Ghadames basins province, hydrocarbons have been trapped mainly in structural highs controlled by paleostructural trends as basement arches which acted as focal points for oil migration and accumulation.

Missallati, A.A. (Agip (N.A.M.E.)Ltd., Tripoli (Libya))

1988-08-01

110

Minneapolis Multi-Ethnic Curriculum Project--Migration Unit.  

Science.gov (United States)

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…

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

111

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

112

Radiation chemistry of hydrocarbons  

International Nuclear Information System (INIS)

This book gives a comprehensive account on the radiation chemistry of hydrocarbons based mainly on the literature published between 1965 and 1977. The treatment of the topics is based on relations between molecular structure and radiation chemical reactivity. Polymerization of hydrocarbons and decomposition of hydrocarbon polymers are excluded. Most of the conclusions have been drawn on the basis of room temperature data obtained from product yields extrapolated to zero dose. The chapters of the book deal with the following topics: absorption of radiation energy, radiation chemistry of aliphatic alkanes, cycloalkanes, aliphatic alkenes and alkynes, cycloalkenes and aromatic hydrocarbons. The last chapter offers a comparison of past results with expected future developments. A subject index is also provided. (Sz.J.)

113

Hydrocarbons (aliphatic and aromatic) in the snow-ice cover in the Arctic  

International Nuclear Information System (INIS)

This paper presented the concentration and composition of aliphatic hydrocarbons and polycyclic aromatic hydrocarbons (PAHs) in snow and ice-infested waters in the France-Victoria trough in the northern Barents Sea and in the Mendeleev ridge in the Amerasian basin of the Arctic Ocean. Extreme conditions such as low temperatures, ice sheets and the polar nights render the arctic environment susceptible to oil spills. Hydrocarbons found in these northern seas experience significant transformations. In order to determine the sources, pathways and transformations of the pollutants, it is necessary to know their origin. Hydrocarbon distributions is determined mostly by natural hydrobiological and geochemical conditions. The regularity of migration is determined by natural factors such as formation and circulation of air and ice drift. There is evidence suggesting that the hydrocarbons come from pyrogenic sources. It was noted that hydrocarbons could be degraded even at low temperatures. 17 refs., 1 tab

114

Hydro geochemistry Study of Yamama formation water in southern Iraqi oil Fields, Migration,Diagensis  

Science.gov (United States)

Yamama Formation (Lower Cretaceous) form one of the main oil reservoir in southern Iraq, the present study deals with the general physical and chemical characteristics of Yamama formation water in selected oil fields - southern Iraq. Via the collecting the available water analysis data in in selected 10 wells in southern Iraqi oil fields, Well Logs, as well as, the technical final well reports. The task of this study is to illustrate the chemical and physical variation among the study oil wells, and their relation with the depositional environment, the grading of temperature and pressure, the reason behind of over pressure phenomenon, besides the delineation of oil migration and water reservoir movement direction. The study confirms the occurrences of two types of formation water; the first one is the connate water, which is brine, hypersaline, and marine in nature reflects the possibility of hydrocarbon accumulations. And the second is mixing water reflects the mixing of original marine water with percolating meteoric water for various degree. Regarding the hydrochemical ratios, the direction of water movement and oil migration is from northeast toward west and south west starting from Messan oil Fields, moreover, the secondary migration of oil is in the same direction. The western migration of oil and water attributed to the enhancement of porosity and permeability in this direction, which in turn means the possibility of finding new stratigraphic traps in this direction mainly western of Nasiriya and Garraf areas. The relationship between depositional environment and diagenetic processes in one hand, and the sediment logical units; tidal lime granular unit revealed the occurrences of khidar al-may which extends up to Al-Managish in Kuwait and Nahar Umar - Majnoon, Nasiriya - Abu Amood, as well as the clayey units represented by isolated and semi isolated lagoonal deposits. Based on the ionic ratios in AlZubair, Nahar Umer and Al-Kifil oil fields, outer shelf clay units was identified as zones extends from Kumait - Halfaia - Noor. This study also showed the major role of diagenetic processes such as dissolution and low dolomitization in granular units in changing the chemical composition of Yamama Formation water under study. The ionic ratios and concentration pointed out the occurrences of many sub-basins within the Yamama main basin. The present study showed the movement of formation water is from the centre of the basin toward the periphery, furthermore, the sulphate index clarify the increases in hydrocarbone preservation toward east and northeast direction. .

Ali, A. A.; SOC Team

2013-05-01

115

MIGRATION IN SIKKIM: FACTS OR FRICTIONS  

Directory of Open Access Journals (Sweden)

Full Text Available Today's migrations become one of the important issues in the globe. The increasing influx of migration and the illegal migration has become a great challenge to the policy maker for both the sending and destination economy. The impact of migration on both the economy has genuine issue to be discusses, analysis and closely study. Therefore, this study reveal to quantify the migration population in Sikkim, to assess the impact on the socio-economy fabrics and to suggest the remedies had to cope up the situation amicably. This study is purely based on secondary data which is collected from Census 1991, Census 2001, Census 2011, A Statistical Profile of Sikkim 2002, State Socio-Economy Census 2006 etc. Migration has positive as well as negative impact on both the economy. Sikkim is a small state touches international boundary with least population and peace loving state. But after merge with the Indian Union the influx of migration is recorded high. Therefore, an attempt has been made to highlight the demographic pattern of Sikkim, economic activities of the migrants and their impact on Sikkim economy

Gyaltsen Tsh. Bhutia

2014-04-01

116

Migration Modes in Cancer Cell Motility  

Science.gov (United States)

Cancer cell metastasis is a result of secondary tumor proliferation after single or collective cancer cell migration from a primary tumor. The biophysical mechanisms of cancer cell migration and transmigration through the body vasculature, while investigated, is not extensively quantified. In general, directed cell motility is traditionally viewed as the result of lamellipodia generation through which the cell moves by extending an actin protrusion and adhesion beneath its plasma membrane. However, cancer cells also exhibit motility through blebbing, which involves momentary membrane detachment from the actin cortex, membrane expansion and retraction. While blebbing, cancer cells do not form cell-substrate attachments as with lamellipodia. In vitro studies of single cancer cell migration through microfluidic microchannels of constant or linearly changing widths model in vitro conditions of single cell migration through capillary pores. We study both modes of motility and observe that cancer cell migration using lamellipodia or blebbing depends on channel width. Drug treatments to manipulate the cytoskeleton demonstrate that cancer cell migration changes speed but not the mode of migration.

Wu, Di; Aranda-Espinoza, Helim

2013-03-01

117

Small angle neutron scattering signature of oil generation in artificially and naturally matured hydrocarbon source rocks  

Energy Technology Data Exchange (ETDEWEB)

We have demonstrated for the first time the application of a small angle neutron scattering (SANS) technique for the precise determination of the onset of hydrocarbon transport (primary migration) in shaly source rocks. We used a sequence of rocks pyrolysed in the laboratory under nitrogen at temperatures in the range 310-370{sup o}C. These rocks contained several percent of dispersed marine Type II organic matter. Geochemical analysis indicated a peak of the hydrocarbon generation in the middle of the temperature range (at 340{sup o}C). We observed a sharp decrease of SANS intensity in a narrow maturity range within the geochemically determined region of the onset of hydrocarbon generation. This decrease was a direct consequence of the SANS contrast variation caused by the invasion of the pore space by bitumen during the primary migration of hydrocarbons. A similar phenomenon was observed for a natural maturity sequence of source rocks originating from the same location. (Author)

Radlinski, A.P.; Boreham, C.J.; Hinde, A.; Hope, J.M. [Australian Geological Survey Organisation, Canberra City (Australia); Lindner, P.; Randl, O. [Institut Max von Laue-Paul Langevin, Grenoble (France); Wignall, G.D. [Oak Ridge National Lab., TN (United States). Center for Small-Angle Scattering Research

2000-07-01

118

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)

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

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

2009-04-01

119

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

Science.gov (United States)

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.

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

2013-02-01

120

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

 
 
 
 
121

Migration and revolution  

Directory of Open Access Journals (Sweden)

Full Text Available The Arab Spring has not radically transformed migration patterns in the Mediterranean, and the label ‘migration crisis’ does not do justice to the composite and stratified reality.

Nando Sigona

2012-06-01

122

Formation of hydrocarbon deposits in a three-layer natural reservoir  

Energy Technology Data Exchange (ETDEWEB)

The theoretical aspect is examined of processes of fluid migration in inhomogeneous media, and in particular, the process of stream migration of hydrocarbons in a fissured-porous medium of three-layer sandy-clay and halide-carbonate natural reservoirs. The analysis enables the conclusion that stream lateral hydrocarbon migration occurs on the boundary of the true cap and the intermediate mass primarily along fissured channels of the intermediate mass, and not along the pore channels of the collector. The traps are filled from above by penetration of the hydrocarbons from the intermediate masses into the collector. Since the oil and gas migration speed in the fissured channels is substantially higher than the speed of diffusion scattering of the hydrocarbons, and the scales of their generation in the oil and gas bearing basins are rather high, the conclusion can be drawn that the fields form quickly, and all traps in the migration's path will be filled to the limit determined by the hypsometry of the true cap in the critical trough. The first traps in the migration's path are initially filled with gas, and rarely oil. The gas can later be eliminated from the trap by the oil, and oil, oil and gas or gas condensate deposits can form in place of the gas deposits. The final result depends on the ratio of the volumes of gaseous hydrocarbons enclosed in the collector and liquid hydrocarbons arriving from above, as well as the pressure in the gas saturated collector. The presence of suspended oil in the gas deposit indicates the possible presence in the formation of an oil fringe. Expulsion of the oil from the trap by the gas is a more difficult process, which is explained by the primary oil content of the ancient platforms.

Il' in, V.D.; Smirnov, L.N.; Spevak, Yu.A.

1982-01-01

123

Lymphocyte migration studies  

Digital Repository Infrastructure Vision for European Research (DRIVER)

For maintenance of immunity and tolerance, the organs and tissues of the organism are connected by migrating lymphoid cells. Understanding lymphocyte migration is essential for many disorders and diseases - especially in the mucosa-lined organs. Detailed analyses of migrating lymphocytes have been performed in many species, especially in laboratory animals. However, important experiments in lymphocyte migration have been carried out in large animals, for example sheep, cattle and pigs. These ...

Bimczok, Diane; Rothko?tter, Hermann

2006-01-01

124

Organic geochemistry of the Vindhyan sediments: Implications for hydrocarbons  

Science.gov (United States)

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.

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

2014-09-01

125

ENVIROMENTAL HYDROCARBON CONTAMINATION IN RICOTTA AND MOZZARELLA DI BUFALA CHEESE  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Polycyclic aromatic hydrocarbons (PAHs), mainly formed by anthropogenic activities, are ubiquitous environmental contaminants. Due to environmental contamination and their chemical properties they migrate through the human food chain. Aim of this study was the evaluation of PAHs in ricotta and mozzarella di bufala cheese, produced by milk of buffalo collected in three farms, located in a high contaminated area in Campania because of a waste treatment plant and illegal waste incineration. 11 P...

Panzardi, M.; Vollano, L.; Cortesi, M. L.; Chirollo, C.; Marrone, R.; Felice, A.; Mercogliano, R.

2013-01-01

126

Polycyclic Aromatic Hydrocarbons  

Science.gov (United States)

The featured molecules for the month of February are a number of polycyclic aromatic hydrocarbons (PAHs) discussed in the article "Fluorescence, Absorption, and Excitation Spectra of Polycyclic Aromatic Hydrocarbons as a Tool for Quantitative Analysis". PAHs are ubiquitous in air, soils, and water as a result of both direct and indirect emissions. PAHs are discharged into environments as byproducts of the combusion of fossil fuels used for transportation and generation of electricity. Other sources of PAH emissions include industrial processes, biomass burning, waste incineration, oil spills, and cigarette smoke.

127

Olefinic hydrocarbon isomerization process  

International Nuclear Information System (INIS)

A process for the isomerization of normal olefinic hydrocarbons is disclosed. The feed stream is passed through a first reaction zone and is then cooled sufficiently to cause the condensation of from about 1 to 25 mole percent of the hydrocarbons in the isomerization zone effluent stream. The uncondensed portion of the effluent of the first reaction zone is heated and passed through a second reaction zone which is maintained at a lower temperature than the first reaction zone. The product isomer is recovered from the effluent of the second reaction zone

128

HYDROCARBONS DIAGNOSTIC OF POLLUTED SOILS  

Directory of Open Access Journals (Sweden)

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.

Mohamed Arad

2010-12-01

129

Chemical isomers of coronoid hydrocarbons  

Science.gov (United States)

A coronoid is a polyhex with one or more holes. Chemical isomers, C nH s, of coronoid hydrocarbons are discussed as an extension of the benzenoid hydrocarbons. A periodic table for single coronoids is proposed, following the style of the Dias periodic table. Some of the lowest isomers of the single coronoid hydrocarbons are enumerated.

Cyvin, S. J.; Brunvoll, J.

1989-12-01

130

Hydrocarbons via photosynthesis  

Energy Technology Data Exchange (ETDEWEB)

Photosynthesis, both natural and as a model process, is examined as a possible annually renewable resource for both material and energy. The conversion of carbohydrate from cane and other sources through fermentation alcohol to hydrocarbon may again become economic in the light of improved fermentation technology and the rising price of hydrocarbon. Even the direct photosynthetic production of hydrocarbon from known sources (Hevea, etc.) or newly bred ones seems possible in view of the large number of species and new techniques of plant cell cloning which have already been successful on sugar cane. Analysis has already begun of other species of Euphorbia which can grow in the United States, especially in California. The molecular weight range of their polyisoprenes is much lower than that for Hevea, being about 10,000 to 30,000 instead of 500,000 to 2,000,000. Since only a few species of Euphorbia have been analyzed and no breeding experiments have been done, both the molecular weight and yield of hydrocarbon may be expected to be very markedly influenced by the new procedures. Finally, more distantly, synthetic systems constructed on the basis of our growing knowledge of the natural photosynthetic processes may produce fuel, fertilizer, and power. From our current knowledge of the natural quantum conversion process in green plants we can envisage several photoelectron transfer processes. Some steps in this sequence of transfer have already been demonstrated in synthetic systems. However, the actual physical construction of such a complete system is a more complex task.

Calvin, M.

1976-09-15

131

Biodegradation of hydrocarbons  

Energy Technology Data Exchange (ETDEWEB)

Hydrocarbons can be degradated by bacteria found in all oceans but in case of oil spills they are too scarce to be efficient rapidly. Development of bacteria requires nutrients forming microemulsions to avoid dispersion in seawater. Behavior of INIPOL EAP 22 developed by Elf Aquitaine is examined. Laboratory and field tests gave good results and the product is not toxic for marine environment.

Sirvins, A.; Tramier, B.

1985-11-01

132

Catalyst for hydrocarbon conversion  

International Nuclear Information System (INIS)

A description is given for a catalyst and process for hydrocarbon conversions, e.g., reforming. The catalyst contains an alumina carrier, platinum, iridium, at least one metal selected from uranium, vanadium, and gallium, and optionally halogen in the form of metal halide of one of the aforesaid components. (U.S.)

133

Migration of mineral oil, photoinitiators and plasticisers from recycled paperboard into dry foods: a study under controlled conditions.  

Science.gov (United States)

Migration from recycled paperboard was monitored after 2, 4 and 9 months of storage for six test foods industrially packed in five configurations, four with internal plastic films. After 9 months, the migration of mineral oil saturated hydrocarbons into foods directly packed in the paperboard amounted to 30-52 mg/kg, which corresponded to 65%-80% of those of a volatility up to that of the n-alkane C?? in the paperboard. The concentration of the migrated aromatic hydrocarbons in the foods ranged from 5.5 to 9.4 mg/kg. More than half of this migration occurred in the first 2 months. Differences between the foods amounted to mostly less than a factor of 2 and seemed to be related to porosity or permeability more than fat content. Nine photoinitiators were detected in the paperboard, of which eight migrated into the packed food at up to 24%. Several plasticisers were present in the recycled paperboard, but only butyl phthalates showed significant migration. After 9 months, up to 40% of diisobutyl phthalate and 20% of dibutyl phthalate migrated into the food with direct contact. The internal polyethylene film hardly slowed migration, but the film and the tray absorbed approximately three times more mineral oil than the food, despite constituting merely 4% of the mass of the pack. Oriented polypropylene strongly slowed migration: The highest migration of saturated hydrocarbons measured after 9 months (2.3 mg/kg) corresponded to only 3% of the content in the paperboard and included migrated polyolefin oligomeric saturated hydrocarbons. Coating of polypropylene with an acrylate further slowed the migration, but the migration from the paperboard was still detectable in four of the six samples. Polyethylene terephthalate was a tight barrier. PMID:23656414

Biedermann, Maurus; Ingenhoff, Jan-Erik; Zurfluh, Michael; Richter, Lydia; Simat, Thomas; Harling, Antje; Altkofer, Werner; Helling, Rüdiger; Grob, Koni

2013-01-01

134

Oil migration pattern in the Sirte Basin  

Energy Technology Data Exchange (ETDEWEB)

Sirte Basin is an asymmetrical cratonic basin, situated in the north-central part of Libya. It covers an area of over 350,000km{sup 2} and is one of the most prolific oil-producing basins in the world. Sirte Basin is divided into large NW-SE trending sub-parallel platforms and troughs bounded by deep seated syndepositional normal faults. A very unique combination of thick sediments with rich source rocks in the troughs vs. thinner sediments with prolific reservoir rocks on the platforms accounts for the productivity of the basin. Analysis of oil migration pattern in the Sirte Basin will certainly help to discover the remaining reserves, and this can only be achieved if the important parameter of structural configuration of the basin at the time of oil migration is known. The present paper is an attempt to analyse the time of oil migration, to define the structural picture of the 4 Basin during the time of migration and to delineate the most probable connecting routes between the hydrocarbon kitchens and the oil fields.

Roohi, M.; Aburawi, R.M. [Waha Oil Co., Tripoli (Libyan Arab Jamahiriya)

1995-08-01

135

Secondary Headaches  

Science.gov (United States)

... doctor often looks for warning signs that would point to a secondary headache over a primary headache. These include: First or ... 36 Million Migraine Campaign today! Copyright © 2011 American Headache Society®. All rights reserved. Disclaimer & Privacy Statement | Site Map | Contact Us

136

Feminization of migrations?  

Directory of Open Access Journals (Sweden)

Full Text Available Women have always taken part in migrations, but their presence varied depending on their origins, on the labour market situation both in the areas of origin and in the target areas, as well as the migration policies in the immigration areas. Their presence was not always visible and did not attract as much scholarly and political attention as today. What happened, how can one explain such an interest lately, whereas only few years ago the subject was marginal, in the shadow of the "mainstream - malestream", i.e. migration as a phenomenon which focuses on geographic mobility of men, while women are not considered as equal protagonists, they either follow or remain at home. Could the so called "feminization" of migration explain the great and sudden interest for women and gender in migrations? This text critically examines the notion of "feminization" considered today as one of the main dimensions of global migration flows. Drawing on trends both globally and in specific countries, it shows that "feminization" is neither a new nor a sudden trend and entails variations depending on the origins, level of development and maturity of migration flows. In some groups men were primo-migrants and with a gradual feminization the flows reach a balanced sex ratio. There where women migrated first, or became numerically predominant, one observs the opposite trend: a "masculinization". Some authors rightly refer to "gender transition", the term which covers both trends. It is argued in the conclusion that the visibility and growing interest for women in migration and, more recently, for a gender perspective in migration, is not only due to the changing migration patterns and profile of migrants but also to the renewal of theoretical perspectives in migration and gender studies in a context that largely facilitated that renewal. The focus of our attention today on specific aspects of migration is triggered not only by genuine changes in migration trends, but it is also a result of a long process of visibilisation in the academic production on migration, women and gender. These trends may have existed earlier in the migration history but had remained in the shadow of categories defining, recording and analyzing migration.

Morokvaši? Mirjana

2010-01-01

137

Migration in Burkina Faso  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Migration plays an important role in development and as a strategy for poverty reduction. A recent World Bank investigation finds a significant positive relationship between international migration and poverty reduction at the country level (Adams and Page 2003). Burkina Faso, whose conditions for agriculture are far from favorable, has a long history of migratory movement, and migration within West Africa has long taken place in response to drought and low agricultural productivity. In recen...

Wouterse, F. S.

2007-01-01

138

Migration and degradation of fuel vapours in the vadose zone. Field experiment at airbase Værløse  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Fuel has been spilled in the vadose zone at many sites. An artificial jet fuel source has been installed in a vadose zone (3.5 m sand) at Airbase Værløse. The field experiment is conducted to investigate the natural attenuation potential in order to obtain better evaluations of the risk for ground water contamination. The migration of the hydrocarbon vapours has been monitored intensively together with the hydrocarbon concentrations in the pore water and the groundwater. The results so far ...

Christophersen, Mette; Broholm, Mette Martina; Kjeldsen, Peter

2006-01-01

139

Aquaporins and cell migration.  

Science.gov (United States)

Aquaporin (AQP) water channels are expressed primarily in cell plasma membranes. In this paper, we review recent evidence that AQPs facilitate cell migration. AQP-dependent cell migration has been found in a variety of cell types in vitro and in mice in vivo. AQP1 deletion reduces endothelial cell migration, limiting tumor angiogenesis and growth. AQP4 deletion slows the migration of reactive astrocytes, impairing glial scarring after brain stab injury. AQP1-expressing tumor cells have enhanced metastatic potential and local infiltration. Impaired cell migration has also been seen in AQP1-deficient proximal tubule epithelial cells, and AQP3-deficient corneal epithelial cells, enterocytes, and skin keratinocytes. The mechanisms by which AQPs enhance cell migration are under investigation. We propose that, as a consequence of actin polymerization/depolymerization and transmembrane ionic fluxes, the cytoplasm adjacent to the leading edge of migrating cells undergoes rapid changes in osmolality. AQPs could thus facilitate osmotic water flow across the plasma membrane in cell protrusions that form during migration. AQP-dependent cell migration has potentially broad implications in angiogenesis, tumor metastasis, wound healing, glial scarring, and other events requiring rapid, directed cell movement. AQP inhibitors may thus have therapeutic potential in modulating these events, such as slowing tumor growth and spread, and reducing glial scarring after injury to allow neuronal regeneration. PMID:17968585

Papadopoulos, M C; Saadoun, S; Verkman, A S

2008-07-01

140

Prävention irregulärer Migration  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Technische Zusammenarbeit mit den Grenzorganen der Auswanderungsländer, massenmediale Vermittlung realitätsgetreuer Informationen über die Einwanderungsländer und Entwicklungsprojekte mit Rückkehrern sind die Hauptschienen der Prävention irregulärer Migration.

Niederberger, Josef Martin; Wichmann, Nicole

2007-01-01

 
 
 
 
141

Holes in hydrocarbons  

International Nuclear Information System (INIS)

Experimental evidence shows that rapid transfer of charge between parent positive ions and neutral molecules in liquid cis- and trans-decalin and cyclohexane (electron-hole migration) takes place. The existence of two conformations of the parent positive ion of cyclohexane, of which one does not transfer charge is suggested. (author)

142

The financial losses from the migration of nurses from Malawi  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 u...

Muula Adamson S; Panulo Ben; Maseko Fresier C

2006-01-01

143

Biomaterial Guides for Lymphatic Endothelial Cell Alignment and Migration  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Axillary dissection during breast cancer surgery produces extensive lymphatic vessel damage that often leads to life-long secondary lymphedema of the arm. We have developed a biodegradable material conduit for lymphatic vessel reconstruction where fibers electrospun along the conduit lumen promote endothelial cell alignment and migration, in vitro. The diameter and density of the electrospun fibers were optimized for cell migration and direction on 2-dimensional substrates by seeding human ly...

Bouta, Echoe M.; Mccarthy, Connor W.; Keim, Alexander; Wang, Han Bing; Gilbert, Ryan J.; Goldman, Jeremy

2011-01-01

144

Planetary migration, accretion, and atmospheres  

Science.gov (United States)

This dissertation explores three distinct projects in the field of planetary formation and evolution: type I migration, cessation of mass accretion, and the atmospheric dynamics of hot Jupiters. All three of these projects touch on outstanding or unresolved issues in the field. Each attempts to unify analytic and numerical approaches in order to physically motivate solutions while simultaneously probing areas currently inaccessible to purely analytic approaches. The first section, type I migration, explores the outstanding problem of the rapid inward migration of low mass planets embedded in protoplanetary disks. Analytic estimates of migration predict characteristic timescales that are much shorter then either observed disk lifetimes or theoretical core-accretion formation timescales. If migration is actually as efficient as these analytic estimates predict, planet formation across the observed range of masses and semimajor axis' is difficult. Here I introduce several new formalisms to both allow the disk to adiabatically adjust to the presence of a planet and include the effect of axisymmetric disk self-gravity. I find that these modifications increase migration timescales by approximately 4 times. In addition to these numerical improvements, I present simulations of migration in lower sound-speed regions of the disk on the grounds that self shadowing within the disk could yield substantially cooler gas temperatures then those derived by most irradiated disk models. In such regions the planetary perturbation excites a secondary instability, leading to the formation of vortices. These vortices cause a substantial reduction in the net torque, increasing migration timescales by up to approximately 200 times the analytically predicted rate. The second section addresses the mechanism for shutting off accretion onto giant planets. According to the conventional sequential accretion scenario, giant planets acquire a majority of their gas in a runaway phase. Conventional mechanisms for stopping this accretion involve either disk dispersal or gap formation. Although mass accretion may eventually be quenched by a global depletion of gas, as in the ease of Uranus and Neptune, such a mechanism is unlikely to have stalled the growth of some known planetary systems which contain relatively low-mass and close-in planets along with more massive and longer period companions. Similarly, the formation of a gap cannot fully explain the decrease in mass accretion. Several groups have shown that, even in the presence of a gap, diffusion allows rapid gas accretion to continue. Here I explore the effect of the growing tidal barrier on the flow within the protoplanetary disk. Using both analytic and numerical approaches I show that accretion rates increases rapidly with the ratio of the protoplanet's Roche to Bondi radii or equivalently to the disk thickness. Mass accretion timescales become comparable to observed disk lifetimes. In regions with loco geometric aspect ratios gas accretion is efficiently quenched with relatively low protoplanetary masses. This mechanism is important for determining the gas- giant planets' mass function, the distribution of their masses within multiple planet systems around solar type stars, and for suppressing the emergence of gas-giants around low mass stars. The final section explores the atmospheric dynamics of short-period gas-giant planets. Ubiquitous among currently observed extrasolar planetary systems these planets receive intense irradiation from their host stars that dominates the energy input into their atmospheres. Characterization of several of these planets through transit observations have revealed information on temperature, structure, and composition. Here we present three-dimensional radiative hydrodynamical simulations of atmospheric circulation on close-in gas giant planets. In contrast to previous Global Climate Models and shallow water algorithms, this method does not assume quasi hydrostatic equilibrium and it approximates radiation transfer from optically thin to thick regions with flux- l

Dobbs-Dixon, Ian M.

145

Radiation-induced cationic polymerization of ?-methylstyrene in hydrocarbon solutions  

International Nuclear Information System (INIS)

The radiation-induced cationic polymerization of ?-methylstyrene has been carried out in several aliphatic and aromatic hydrocarbon solutions in order to study the chain transfer reaction to the solvents. The rate of the chain transfer reaction to C6 aliphatic hydrocarbons is in the order: 2,2-dimethylbutane < 2,3-dimethylbutane < n-hexane approximately = 3-methylpentane. The result has been explained by the fact that the reactivity in hydride transfer increases in the order: primary < secondary < tertiary hydrogens. The activation energy of the chain transfer to n-hexane is 9 kcal/mol higher than that to monomer. The rate of the chain transfer to aromatic hydrocarbons increases in the order: benzene < toluene < m-xylene. It has been suggested that the hydride transfer from the methyl groups of the substituted benzenes occurs as well as the electrophilic substitution of benzene rings. (author)

146

Generation and migration of oil from perhydrous Longyear coal  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Hydrous pyrolysis of immature Longyear coal samples was done to assess the source of bitumen found in the coal, the petroleum generation potential and the possibility of liquid hydrocarbon migration within the coal. Hydrous pyrolysis results obtained showed an impressive average bitumen yield of 320 mg/g TOC which increases towards the upper portion of the seam. This increase coincides with an increase in original hydrogen content and hydrogen index of the samples indicating an improvement ...

Mokogwu, Ikechukwu

2011-01-01

147

SAMPLING DURATION DEPENDENCE OF SEMI-CONTINUOUS ORGANIC CARBON MEASUREMENTS ON STEADY STATE SECONDARY ORGANIC AEROSOLS  

Science.gov (United States)

Semi-continuous organic carbon concentrations were measured through several experiments of statically generated secondary organic aerosol formed by hydrocarbon + NOx irradiations. Repeated, randomized measurements of these steady state aerosols reveal decreases in the observed c...

148

HYDROCARBON CONSTITUENTS OF ICELAND LEAF FOSSIL  

Energy Technology Data Exchange (ETDEWEB)

The hydrocarbon content of leaf fossils from Iceland has been investigated by gas chromatography-mass spectrometry. The distribution patterns of normal hydrocarbons, branched hydrocarbons, and cyclic hydrocarbons are compared to those of present-day living organisms. The diagenetic pathways of these hydrocarbons are discussed.

Han, Jerry; Calvin, Melvin.

1970-10-01

149

Measuring Trace Hydrocarbons in Silanes  

Science.gov (United States)

Technique rapid and uses standard analytical equipment. Silane gas containing traces of hydrocarbons injected into carrier gas of moist nitrogen having about 0.2 percent water vapor. Carrier, water and silane pass through short column packed with powdered sodium hydroxide which combines moisture and silane to form nonvolatile sodium silicate. Carrier gas free of silane but containing nonreactive hydrocarbons, pass to silica-gel column where chromatographic separation takes place. Hydrocarbons measured by FID.

Lesser, L. A.

1984-01-01

150

Migration Information Source  

Science.gov (United States)

Recently introduced by the Migration Policy Institute, the Migration Information Source Web site offers visitors a fantastic opportunity to stay on top of trends and changes in global migration. Looking at migration from many levels and on many planes, the site considers migrations on both national and international fronts. With a dropdown menu of the countries for which data is available (currently western European countries, Australia, and the US), the database is fully searchable, with more options on the way. Perhaps most interesting to those directly working in statistical, sociological, or ethnographic analyses of migration, the resource is broadly accessible and offers compelling glimpses of migrant populations, their reasons for moving, and their rates of assimilation into host countries. For those unfamiliar with field-specific terms employed in the site's reports, there is a detailed glossary of common terms and phrases. Closer to home, the Migration Information site presents an elaborate array of reports and studies on US-Mexico relations, with an emphasis on the ever-broadening trend toward northward migration in the Americas.

151

[Migration to metropolitan Mexico City].  

Science.gov (United States)

Accelerated urbanization, especially after 1940, has been among the great transformations in Mexico associated with rapid and sustained economic growth during 1950-80. The urbanization process was highly selective, favoring in particular Mexico City, Guadalajara, and Monterey, which together contain about 25% of Mexico¿s total population. Metropolitan Mexico City alone contained around 18.2% of the total 1990 population on 0.2% of Mexico¿s land area. Mexico City¿s population grew at an average annual rate of 4.2%, from 1.6 million in 1940 to 14.8 million in 1990, largely due to in-migration. Migrants and their reproduction are estimated to have accounted for 51.2% of Mexico City¿s growth since 1940, and physical expansion of the metropolitan zone for another 5.7%. Slightly over 80% of migrants come from 10 states that are mostly rural, relatively densely populated, not distant, and below average in living levels. Women predominate slightly. Nearly half of migrants are aged 15-29 years on arrival. The proportion with no more than primary education is higher than that of Mexico City natives, but the proportion with post-secondary education is similar. Pollution, lack of public safety, and other urban problems will probably combine to discourage migration to Mexico City in the future and encourage departures to less difficult cities. PMID:12158091

Cantu Gutierrez, J J; Luque Gonzalez, R

1990-01-01

152

Migration of health workers.  

Science.gov (United States)

The discussion and debate stimulated by these papers focused across a range of issues but there were four main areas of questioning: "measuring" and monitoring migration (issues related to comparability, completeness and accuracy of data sets on human resources); the impact of migration of health workers on health systems; the motivations of individual health workers to migrate (the "push" and "pull" factors) and the effect of policies designed either to reduce migration (e.g "self ufficiency") or to stimulate it (e.g active international recruitment). It was recognised that there was a critical need to examine migratory flows within the broader context of all health care labour market dynamics within a country, that increasing migration of health workers was an inevitable consequence of globalisation, and that there was a critical need to improve monitoring so as to better inform policy formulation and policy testing in this area. PMID:18561695

Buchan, James

2008-01-01

153

Electron trapping in alcohol clusters in ?-irradiated n-propanol-hydrocarbon glasses at 77 K  

International Nuclear Information System (INIS)

A study has been made of trapped electrons in n-propanol-hydrocarbon mixture glasses at 77 K by the optical absorption method. The yields of electrons trapped in alcohol clusters (e sub(alc)sup(-)) were measured for several ?-irradiated n-propanol-hydrocarbon glasses, where the yields of trapped electrons in these neat hydrocarbon glasses at 77 K are known to range from 0.015 to 1.1 G units. The results show that the yields of e sub(alc) sup(-) in the mixture glasses does not depend on the trapped electron yields in neat hydrocarbon glasses. Thus, it is concluded that electron migration from relaxed hydrocarbon matrix traps into alcohol clusters is not the major process for e sub(alc) sup(-) formation in the systems studied here. The major process for e sub(alc) sup(-) formation may be attributed to quasi-free electron scavenging by alcohol clusters and electron migration from unrelaxed hydrocarbon traps into alcohol clusters. Both ir-induced and isothermal changes in the e sub(alc) sup(-) yield have also been investigated. These investigations indicate that there is a correlation between the observed change in the e sub(alc) sup(-) yield and the matrix viscosity

154

HEURISTICAL STRATEGIES ON THE STUDY THEME “THE UNSATURATED HYDROCARBONS – ALKENES”  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 experiment, brain storming, modeling, problematization. The results obtained in the research demonstrate the efficiency of interactive methods in teaching...

Adrienne Kozan Naumescu; Roxana-Diana Pa?ca

2011-01-01

155

Secondary organic aerosol formation and transport  

Science.gov (United States)

A Lagrangian trajectory model simulating the formation, transport and deposition of secondary organic aerosol is developed and applied to the Los Angeles area, for the air pollution episode of 27-28 August 1987. The predicted secondary organic aerosol on 28 August 1987 represents 15-22% of the measured particulate organic carbon at inland locations in the base case simulations, and 5-8% of that at coastal locations. A maximum secondary organic aerosol concentration of 6.8 ?g m -3 is predicted for Claremont, CA, during this episode. On a daily average basis at Claremont about 46% of this secondary organic aerosol is predicted to be a result of the oxidation of non-toluene aromatics (xylenes, alkylbenzenes, etc.), 19% from toluene, 16% from biogenic hydrocarbons (?-pinene, ß-pinene, etc.), 15% from alkanes and 4% from alkenes. The major uncertainties in predicting secondary organic aerosol concentrations are the reactive organic gas emissions, the aerosol yields and the partitioning of the condensable gases between the two phases. Doubling the reactive organic gas (ROG) emissions results in an increase of the secondary organic aerosol predicted at Claremont by a factor of 2.3. Predicted secondary organic aerosol levels are less sensitive to changes in secondary organic aerosol deposition and NO x emissions than to ROG emissions.

Pandis, Spyros N.; Harley, Robert A.; Cass, Glen R.; Seinfeld, John H.

156

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

157

Fractionation of Hydrocarbons Between Oil and Gas Phases Fractionnement des hydrocarbures entre les phases huile et gaz  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The investigation of hydrocarbon fractionation between oil and gas phases is of interest for several purposes in reservoir exploitation. In reservoir geochemistry, the evolution of light hydrocarbon fractions of oils may explain some migration phenomena. In gas injection projects, the preferred dissolution of some components in gas may alter the composition as well as the properties of the oil. Underground gas storage in depleted oil reservoirs may also be concerned by these problems. Results...

Ruffier-Meray V.; Ungerer P.; Carpentier B.; Courcy J. P.

2006-01-01

158

Migration without migraines  

Energy Technology Data Exchange (ETDEWEB)

Accurate velocity models are a necessity for reliable migration results. Velocity analysis generally involves the use of methods such as normal moveout analysis (NMO), seismic traveltime tomography, or iterative prestack migration. These techniques can be effective, and each has its own advantage or disadvantage. Conventional NMO methods are relatively inexpensive but basically require simplifying assumptions about geology. Tomography is a more general method but requires traveltime interpretation of prestack data. Iterative prestack depth migration is very general but is computationally expensive. In some cases, there is the opportunity to estimate vertical velocities by use of well information. The well information can be used to optimize poststack migrations, thereby eliminating some of the time and expense of iterative prestack migration. The optimized poststack migration procedure defined here computes the velocity model which minimizes the depth differences between seismic images and formation depths at the well by using a least squares inversion method. The optimization methods described in this paper will hopefully produce ``migrations without migraines.``

Lines, L.; Burton, A.; Lu, H.X. [Memorial Univ. of Newfoundland, St. John`s (Canada)

1994-12-31

159

Secondary sources  

International Nuclear Information System (INIS)

An experimental neutron beam reactor essentially is an intense source of thermal neutrons for carrying out experiments in the fields of: - Solid state physics (including chemical and biological applications); - Nuclear physics and possibly neutron physics. The majority of these experiments are carried out at thermal neutron beam tubes with a minimized background of fast and epithermal neutrons and of gamma radiation. Moreover, facilities integrated in the reactor exist, which are designed to produce (and then to permit the extraction of) neutrons in well defined energy ranges by means of specific moderators. Essentially, such facilities are: - Cold neutron sources (CNSs) realized by the insertion of a low temperature moderator operated below 25 K; - Hot neutron sources (HNSs) realized by the insertion of a high temperature moderator operated at about 2000 K. This paper illustrates some of the features of those facilities and will use the French secondary sources as relevant examples

160

Glossary: migration and health.  

Science.gov (United States)

The literature on migration and health is quite heterogeneous in how migrants are labelled and how the relation between migration and health is conceptualised. A narrative review has been carried out. This glossary presents the most commonly used terms in the field of migration and health, along with synonyms and related concepts, and discusses the suitability of their use in epidemiological studies. The terminology used in migrant health is ambiguous in many cases. Studies on migrant health should avoid layman terms and strive to use internationally defined concepts. PMID:21282138

Urquia, Marcelo L; Gagnon, Anita J

2011-05-01

 
 
 
 
161

Synthesis of hydrocarbons under upper mantle conditions: Evidence for the theory of abiotic deep petroleum origin  

International Nuclear Information System (INIS)

A theory of abiotic deep petroleum origin explains that hydrocarbon compounds are generated in the upper mantle and migrate through the deep faults into the Earth's crust. There they form oil and gas deposits in any kind of rock in any kind of the structural position. Until recently one of the main obstacles for further development of this theory has been the lack of reliable and reproducible experimental results confirming the possibility of the spontaneous synthesis of complex hydrocarbon systems at high pressure and temperature. Our experimental results demonstrate that abiotic synthesis of hydrocarbons under mantle conditions is a real chemical process. Different paths of hydrocarbon synthesis under mantle conditions are discussed. Obtained experimental results place the theory of the abiotic deep petroleum origin in the mainstream of modern experimental physics and physical chemistry.

162

Synthesis of hydrocarbons under upper mantle conditions: Evidence for the theory of abiotic deep petroleum origin  

Science.gov (United States)

A theory of abiotic deep petroleum origin explains that hydrocarbon compounds are generated in the upper mantle and migrate through the deep faults into the Earth's crust. There they form oil and gas deposits in any kind of rock in any kind of the structural position. Until recently one of the main obstacles for further development of this theory has been the lack of reliable and reproducible experimental results confirming the possibility of the spontaneous synthesis of complex hydrocarbon systems at high pressure and temperature. Our experimental results demonstrate that abiotic synthesis of hydrocarbons under mantle conditions is a real chemical process. Different paths of hydrocarbon synthesis under mantle conditions are discussed. Obtained experimental results place the theory of the abiotic deep petroleum origin in the mainstream of modern experimental physics and physical chemistry.

Kutcherov, V.; Kolesnikov, A.; Dyuzheva, T.; Brazhkin, V.

2010-03-01

163

ENVIROMENTAL HYDROCARBON CONTAMINATION IN RICOTTA AND MOZZARELLA DI BUFALA CHEESE  

Directory of Open Access Journals (Sweden)

Full Text Available Polycyclic aromatic hydrocarbons (PAHs, mainly formed by anthropogenic activities, are ubiquitous environmental contaminants. Due to environmental contamination and their chemical properties they migrate through the human food chain. Aim of this study was the evaluation of PAHs in ricotta and mozzarella di bufala cheese, produced by milk of buffalo collected in three farms, located in a high contaminated area in Campania because of a waste treatment plant and illegal waste incineration. 11 PAHs were identified both in milk and dairy products. Carcinogenic hydrocarbon benzo(apyrene were found in a range including 0.42- 12.96 ?g/kg and dibenzo(ahanthracene 0.21-10.08 ?g/kg. Anthracene showed higher concentrations than the other PAHs (45.23-436.85 ?g/kg.

M.L. Cortesi

2010-06-01

164

Migration og etnicitet  

DEFF Research Database (Denmark)

Migration og etnicitet er aktuelle og forbundne fænomener, idet migration øger berøringsfladerne mellem befolkningsgrupper. Etniciteter formes i takt med at grænser drages imellem disse grupper. Imod moderniserings-teoriernes forventning forsvandt etnicitet ikke som en traditionel eller oprindelig måde at skabe tilhørsforhold på; globalt set fremstår vor tid istedet som en "migrationens tidsalder", der tilsyneladende også er en tidsalder, hvor kulturelle særtræk, i form af etnicitet, udgør vigtige linjer, hvorefter grupper skilller sig ud fra hinanden. Både migration og etnicitet bringer fokus på nationalstaten, dens suverænitet og kapaciteten hos dens institutioner til henholdsvis at regulere bevægelser over statsgrænser og til at definere de former for fællesskab, som præger de enkelte samfund. I sociologien har man tidligere primært koncentreret sig om studier af migrationsprocessen som den finder sted i modtagerlandet, men nyere perspektiver på migration, som begreber om medborgerskab, transnationalisme og diaspora er eksponenter for, søger udover den nationalstatslige ramme og inddrager konsekvenserne af migrationen for afsenderlande.

Christiansen, Connie CarØe

2004-01-01

165

Migration and Narration  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The following article aims to work out the main narrative techniques of “telling migration”. The conclusions drawn on the subject of migration and narration are based on a one-year field work study, combining participant observation with interviewing. This study took place in New Zealand concentrating on German immigrants between 1936 and 1996. The main source for my analysis given in this paper is provided by 102 people I interviewed. The texts of these biographically-focussed int...

Brigitte Boenisch-Brednich

2002-01-01

166

Migration and Narration  

Directory of Open Access Journals (Sweden)

Full Text Available The following article aims to work out the main narrative techniques of “telling migration”. The conclusions drawn on the subject of migration and narration are based on a one-year field work study, combining participant observation with interviewing. This study took place in New Zealand concentrating on German immigrants between 1936 and 1996. The main source for my analysis given in this paper is provided by 102 people I interviewed. The texts of these biographically-focussed interviews allowed me to work not only on an ethnographical history of migration but also to gain insights into peoples’ experiences, and over and above that, to learn what kind of stories and techniques of storytelling emigration creates. The book focuses on a comparatively wide time frame of sixty years (Boenisch- Brednich 2001. This makes it possible to analyse very different periods of migration and groups of migrants, contrasting social categories as well as exploring differences in education, milieu, age and gender. Furthermore, it becomes obvious that although all migrants were leaving Germany and arriving in New Zealand, they experienced what were in effect very different countries through time – different Germanys, different New Zealands. To work out the changing reasons for migrating (work migration, refuge, global lifestyle, etc. inside western societies is a major theme the book is aiming for. A second approach is to investigate migration from the perspective of focussing on everyday life, an investigation on the basis of personal experiences, such as “work, housing, food, celebrations, social life”. A special focus is set on the analysing of “mental narratives” as key stories, examples, comparatives etc. The central questions of this project were: What kind of strategies do people use to cope with a major changes in their biography, as constituted by emigration? What does integration really mean and how does it work for different groups? What kind of collective and individual stories does migration create? In which ways does retroperspection work as a technique for creating autobiographies in oral transmission?

Brigitte Boenisch-Brednich

2002-05-01

167

Defining lifestyle migration  

Directory of Open Access Journals (Sweden)

Full Text Available This paper seeks to provide a conceptual framework for studying migration to the Algarve by Northern Europeans. ‘Lifestyle migration’ is suggested as a generic term for this trend, which is part of a recent but flourishing global social phenomenon. I also point to the glaring gap in the literature as far as empirical studies based in the Algarve are concerned, and make suggestions for a research agenda.

Kate Torkington

2010-04-01

168

Indonesia's migration transition.  

Science.gov (United States)

This article describes population movements in Indonesia in the context of rapid and marked social and economic change. Foreign investment in Indonesia is increasing, and global mass media is available to many households. Agriculture is being commercialized, and structural shifts are occurring in the economy. Educational levels are increasing, and women's role and status are shifting. Population migration has increased over the decades, both short and long distance, permanent and temporary, legal and illegal, and migration to and between urban areas. This article focuses specifically on rural-to-urban migration and international migration. Population settlements are dense in the agriculturally rich inner areas of Java, Bali, and Madura. Although the rate of growth of the gross domestic product was 6.8% annually during 1969-94, the World Bank ranked Indonesia as a low-income economy in 1992 because of the large population size. Income per capita is US $670. Indonesia is becoming a large exporter of labor to the Middle East, particularly women. The predominance of women as overseas contract workers is changing women's role and status in the family and is controversial due to the cases of mistreatment. Malaysia's high economic growth rate of over 8% per year means an additional 1.3 million foreign workers and technicians are needed. During the 1980s urban growth increased at a very rapid rate. Urban growth tended to occur along corridors and major transportation routes around urban areas. It is posited that most of the urban growth is due to rural-to-urban migration. Data limitations prevent an exact determination of the extent of rural-to-urban migration. More women are estimated to be involved in movements to cities during the 1980s compared to the 1970s. Recruiters and middlemen have played an important role in rural-to-urban migration and international migration. PMID:12347370

Hugo, G

1995-01-01

169

Membranous nephropathy following exposure to volatile hydrocarbons  

Energy Technology Data Exchange (ETDEWEB)

Excessive exposure to solvents has long been known to cause renal tubular disease in man. Recently, the occurrence of glomerular disease such as Goodpasture's syndrome with proliferative and extracapillary glomerulonephritis has been related to hydrocarbon exposure. This report concerns four patients with membranous nephropathy who had a history of prolonged exposure to a number of volatile hydrocarbons. Membranous nephropathy is a chronic renal disease involving glomeruli and occurring principally in adults. Its clinical onset is insidious and is manifested by proteinuria or edema. Proteinuria is the hallmark of the disease and may be present for many years without symptoms. It is often a slowly progressive disease. About one-fourth of the patients improve clinically and lose their proteinuria, while up to one-fourth develop renal failure. The glomerular capillary wall lesions are distinctive, contain deposits of immunoglobulin and complement considered to represent immune-complexes, and show a morphological progression from early Stage I to late Stage IV. While in most cases there is no known etiology, in some patients the disease has been deemed to be secondary to specific diseases or agents such as infections, neoplasms, or chemicals. The four cases described fall into this last category.

Ehrenreich, T.; Yunis, S.L.; Churg, J.

1977-01-01

170

Process for recovering hydrocarbons from a hydrocarbon-bearing formation  

Energy Technology Data Exchange (ETDEWEB)

A method is described for transporting heavy crude oil through a pipeline which involves introducing into a pipeline or well-bore with the viscous hydrocarbons an aqueous solution containing (1) a sulfonate surfactant, (2) a rosin soap or a naphthenic acid soap and, optionally (3) coupling agent whereby there is spontaneously formed a low viscosity, salt tolerant, oil-in-water emulsion. Also disclosed is a method of recovery of hydrocarbons from a hydrocarbon bearing formation employing an aqueous solution containing (1) a sulfonate surfactant, (2) a rosin soap or a naphthenic acid soap and, optionally (3) a coupling agent.

Alston, R.B.; Braden, W.B.; Flournoy, K.H.

1980-03-11

171

Migration and malaria.  

Science.gov (United States)

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

Jitthai, Nigoon

2013-01-01

172

Internal migration in Tunisia.  

Science.gov (United States)

Migration estimation from surveys is a very recent development. Most countries have depended upon questions of place of birth in the censuses. The present study is concerned with internal migration of Tunisia during 1968-1969 as revealed by Tunisian National demographic survey utilizing the residence in 1968 (1st round) and 1969 (3rd round). An attempt is made to derive volume and rates of migration between regions and other characteristics. The basic purpose of the survey was to fill in gaps that existed in Tunisian demography and to permit the calculation of life tables for Tunisia. For this survey 25 thousand households were selected randomly from specified areas in 2 stages using 1966 census listing of households. The follow up of individual sample members between the 1st round the 3rd round gives an indication of the extent of migration. A migrant is defined as a person who moved from his cheikhat (or commune) for a period exceeding the period of observation. The highlights of study are summarized as follows: Tunis accounted for the greatest number of migrants (17.9%). The migration abroad is appreciable (11.7%). The Sahel and the Haut-Tell are the most important zones of out-migration, principally to Naubel and Tunis. The movements between neighboring governorates in the Haut-Tell, is by stages. Beja receives from Jendouba and Le Kef to send to Tunis and Bizerte. PMID:12264776

Abdellatif, B H

1976-02-01

173

Return Migration, Wage Differentials, and the Optimal Migration Duration  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In simple static models, migration increases with the wage differential between host and home country. In a dynamic framework, and if migrations are temporary, the size of the migrant population in the host country depends also on the migration duration. This paper analyses optimal migration durations in a model which rationalises the decision of the migrant to return to his home country, despite persistently higher wages in the host country. The analysis shows that, if migrations are tempora...

Dustmann, Christian

2001-01-01

174

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

175

Halogenated aliphatic hydrocarbon nephrotoxicity  

International Nuclear Information System (INIS)

Dietary ingestion of polybrominated biphenyls (PBB) and polychlorinated biphenyls (PCB) increased renal and hepatic aryl hydrocarbon hydroxylase (AHH) activities in a dietary concentration-dependent manner. Mixed-function oxidase (MFO) activities were also induced in liver and kidney by i.p. administration of 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD) and 3-methylcholanthrene (3MC), but sodium phenobarbital (NaPb) increased hepatic MFO activities only. Renal and hepatic AHH activities and cytochrome P-450 (P-450) concentrations is male, Fischer 344 rats were increased by treatments with PBB, PCB and 3MC. NaPb increased hepatic AHH activity and P-450 content only. The rates of increase (and decline to normal values) of AHH activities following single oral doses of PBB, PCB, and 3MC were much greater in the kidneys than in the liver

176

Permeable bio-reactive barriers for hydrocarbon remediation in Antarctica  

Energy Technology Data Exchange (ETDEWEB)

This study assessed the performance of a permeable bio-reactive barrier designed to treat contaminated water. The bio-reactive barrier was installed at a fuel spill site located in the Windmill Islands, Antarctica. A funnel and gate design was used to prevent contaminant migration beyond the barrier location as well as to ensure controlled nutrient delivery. The study also investigated the performance of the bio-reactive barrier in regions with freeze-thaw conditions. The 4-year project was also conducted to assess optimal conditions for enhancing the barrier's ability to degrade hydrocarbons.

Mumford, K.A.; Stevens, G.W.; Gore, D.B. [Melbourne Univ., Victoria (Australia). Dept. of Chemical and Biomoleculuar Engineering, Particulate Fluids Processing Centre; Snape, I.; Rayner, J.L. [Australian Antarctic Div., Kingston, Tasmania (Australia); Gore, D.B. [Macquarie Univ., Sydney, NSW (Australia). Dept. of Environmental Science

2010-07-01

177

Hydrocarbons in Washington coastal sediments  

Science.gov (United States)

The sources and distributions of polycyclic aromatic hydrocarbons (PAH) and aliphatic hydrocarbons are characterized in seventeen sediments from a highly river-influenced sedimentary environment off the southwestern coast of Washington. The major hydrocarbons are land-derived, introduced as preformed compounds and display long-term stability in sediment cores. A series of PAH of anthropogenic origin and two naturally derived compounds, retene and perylene, dominate the PAH composition in these sediments. Plantwax n-alkanes are the major aliphatic hydrocarbon constituents. Aliphatic hydrocarbons of marine origin, pristane and a series of four acyclic, multibranched C 25 polyolefins, are also observed in many sediments. The concentrations of these marine-derived hydrocarbons decrease to negligible levels rapidly with sediment depth from the sea-sediment interface, suggesting degradation. In general, the major land-derived hydrocarbons are concentrated in the midshelf silt deposit which extends northwestward along the continental shelf from the Columbia River mouth. A quantitatively more minor, natural series of phenanthrene homologs, also of terrestrial origin, is preferentially advected further offshore and deposited in continental slope sediments. These distributions are consistent with recognized particle associations for these compounds and sediment dispersal processes in this coastal environment. Sediment core records suggest the present pattern of dispersal has persisted for at least the past century and possibly since the Late Pleistocene.

Prahl, Fredrick G.; Carpenter, Roy

1984-06-01

178

Subduction zone earthquake probably triggered submarine hydrocarbon seepage offshore Pakistan  

Science.gov (United States)

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.

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

2014-05-01

179

Globalization, Migration and Development  

Directory of Open Access Journals (Sweden)

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.

George, Susan

2002-01-01

180

Atlantic Salmon Migration Past Barriers  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The Atlantic salmon depend on successful migration between essential habitats in freshwater and the ocean. However, during both downstream and upstream migration the fish encounter natural or manmade obstacles which can block or delay their migration and migration through hydropower turbine can cause severe mortality. This PhD-study has focused the salmon migration challenges, upstream and downstream, based on studies in Norwegian rivers, and the results are presented in four scientific paper...

Fjeldstad, Hans-petter

2012-01-01

 
 
 
 
181

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

182

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

183

Planet Formation with Migration  

CERN Document Server

In the core-accretion model, gas-giant planets form solid cores which then accrete gaseous envelopes. Tidal interactions with disk gas cause a core to undergo inward type-I migration in 10^4 to 10^5 years. Cores must form faster than this to survive. Giant planets clear a gap in the disk and undergo inward type-II migration in <10^6 years if observed disk accretion rates apply to the disk as a whole. Type-II migration times exceed typical disk lifetimes if viscous accretion occurs mainly in the surface layers of disks. Low turbulent viscosities near the midplane may allow planetesimals to form by coagulation of dust grains. The radius r of such planetesimals is unknown. If r<0.5 km, the core formation time is shorter than the type-I migration timescale and cores will survive. Migration is substantial in most cases, leading to a wide range of planetary orbits, consistent with the observed variety of extrasolar systems. When r is of order 100m and midplane alpha is of order 3 times 10^-5, giant planets si...

Chambers, J E

2006-01-01

184

Formation of hydrocarbons under upper mantle conditions: experimental view  

Science.gov (United States)

Main postulates of the theory of abiogenic abyssal origin of petroleum have been developed in the last 50 years in Russia and Ukraine. According to this theory, hydrocarbon compounds were generated in the mantle and migrated through the deep faults into the Earth's crust. There they formed oil and gas deposits in any kinds of rocks and in any kind of their structural positions. Until recently the main obstacle to accept the theory was the lack of reliable and reproducible experimental data confirming the possibility of the synthesis of complex hydrocarbon systems under the mantle conditions. The results received in the last decade by different groups of researchers from Russia, U.S.A. and China have confirmed the possibility of generation of hydrocarbons from inorganic materials, highly distributed in the Earth's mantle, under thermobaric conditions of 70-250 km: 2 - 5 GPa and 1000-1500 K. Experiments made in the CONAC chamber at pressures of 3-5 GPa and temperatures of 1000-1500 K by Kutcherov et al. [1, 2] have demonstrated that the mixtures of hydrocarbons with composition similar to natural hydrocarbon systems have been received as a result of chemical reactions between CaCO3, FeO and H2O. Methane formation from the same compounds was registered after heating up to 600-1500 K at pressures of 4-11 GPa in diamond anvil cells [4, 5, 6]. Influence of oxidation state of carbon donor and cooling rate of the fluid synthesized at high pressure were studied using different types of high pressure equipments. It was shown that composition of the final hydrocarbon mixture depends on these parameters. Experimental investigations of transformation of methane and ethane at 2-5 GPa and 1000-1500 K [3] confirmed thermodynamic stability of heavy hydrocarbons in the upper mantle and showed the possibility of hydrocarbon chain growth even at oxidative environment. For development of the theory of abiogenic abyssal origin of petroleum it is necessary to arrange a set of new experiments to understand the pathways of hydrocarbons formation, influence of pressure, temperature, oxygen fugacity and chemical composition of the environment on the content of the mantle fluid. [1] Kutcherov, V. G., Bendeliani, N. A. Alekseev, V. A. & Kenney, J. F. Synthesis of Hydrocarbons from Minerals at Pressures up to 5 GPa. Doklady Physical Chemistry, 387, 4-6, 328-330 (2002). [2] Kenney, J. F., Kutcherov, V. G., Bendeliani, N. A. & Alekseev, V. A. The Evolution of Multicomponent Systems at High Pressures: VI. The Thermodynamic Stability of the Hydrogen-Carbon System: The Genesis of Hydrocarbons and the Origin of Petroleum. Proc. Natl. Acad. Sci. U.S.A., 99, 10976-10981 (2002). [3] Kolesnikov A., Kutcherov V. G. and Goncharov A. F. Methane-derived hydrocarbons produced under upper-mantle conditions. Nature Geoscience, 2, 566 - 570 (2009). [4] Scott H.P., Hemley R.J, Mao H. et al. Generation of methane in the Earth's mantle: In situ high pressure-temperature measurements of carbonate reduction, Proc. Natl. Acad. Sci. U.S.A., 101 14023-14026 (2004). [5] Chen J.Y., et al. Methane formation from CaCO3 reduction catalyzed by high pressure. Chin. Chem. Lett., 19, 4, 475-478 (2008). [6] Sharma A., Cody G. D., and Hemley R. J. In situ Diamond-anvil cell observations of methanogenesis at high pressures and temperatures. Energy Fuels, 23, 11, 5571-5579 (2009).

Kolesnikov, Anton; Kutcherov, Vladimir G.

2010-05-01

185

Migration mechanisms of radionuclides from a clay repository toward adjacent aquifers and the surface  

International Nuclear Information System (INIS)

This article is a critical review of the current understanding of migration processes of solutes in clay. The major migration mechanisms are examined: advection through compaction, thermal convection, migration by hydrocarbon expulsion, gravitational flow, osmosis, molecular diffusion, hydrodynamic dispersion. Examples are taken from the Callovo-Oxfordian clays of the Paris basin in the Meuse/Haute Marne area, near Bure, where France is studying the feasibility of a potential nuclear waste disposal facility. Recent work on the helium distribution in the aquifers of the Paris Basin confirms the importance of molecular diffusion for solute transport in clays. Migration in aquifers is also described, and the major causes of uncertainties for solute migration are discussed. (authors)

186

Odorization of combustible hydrocarbon gases  

Energy Technology Data Exchange (ETDEWEB)

Described is a warning agent for the odorization of gaseous hydrocarbon fuels based on mixtures of at least one of the compounds, 2-methooxy-3-isobutyl pyrazine and 4-methyl-4-mercapto-2-pentanone with a monomercaptan or a sulfide.

Yoshida, T.; Katz, I.; Warren, C. B.; Wiener, C.

1984-12-11

187

Analysis of Near Surface Hydrocarbon Distribution Pattern Around the Eileen Fault zone, Alaska North Slope  

Science.gov (United States)

Methane hydrate (a crystalline solid in which water molecules form an ice-like framework that trap gas molecules) is an attractive energy resource because of its high energy density as compared to other naturally occurring forms of methane, and its relatively close proximity to the Earth's surface and seafloor. Methane hydrate distribution on the Alaska North Slope (ANS) Prudhoe Bay region is thought to be controlled by the availability of migrated thermogenic methane gas from depth. The Eileen Fault Zone coincides with a known region of shallow (less than 1000m) gas hydrates, indicating possible control of the gas hydrates by the Eileen faults. Should the faults be controlling the migration of hydrocarbons from depth, one would expect higher concentrations of hydrocarbons in the proximity of the Eileen Fault zone. Geochemical concentrations of hydrocarbons, taken from shallow surface (3m depth) soil samples around the Eileen Fault zone, is evidence for such migration and indicate target for further gas hydrate research and development in the area. Initial results by the USGS revealed correlations between high concentrations of helium, methane, pentane and hexane. This study uses an Inverse Distance Weighted (IDW) technique to display interpolated surfaces between transect sample points of the same hexane, pentane, methane and helium concentrations. Buffers are also placed around the fault zone in order to show possible migration zones around the Eileen should the fault dip at 10 degrees or 30 degrees. Initial results show hexane and pentane display zones of high concentrations within the buffered zones. Helium and methane display several zones of high concentration outside the buffered areas. The significance of these results further supports the hypothesis that the Eileen Fault is a migration path way with several zones of seepage for hydrocarbons at depth. The anomalous concentration zones falling within the buffered zones are an indication of this seepage.

Papp, K. A.; Prakash, A.; Hanks, C.; Collett, T. S.

2006-12-01

188

Bioassay of polycyclic aromatic hydrocarbons  

Energy Technology Data Exchange (ETDEWEB)

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.

Van Kirk, E.A.

1980-08-01

189

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

Kolesnikov, Anton

2010-01-01

190

Quandary of migrated IUCD  

Directory of Open Access Journals (Sweden)

Full Text Available Intra Uterine Contraception Device (IUCD is the most widely used method of reversible contraception. However complications are known to occur with IUCD. Although uterine perforation is not very rare, but asymptomatic migration into urinary bladder and mesoappendix, is a very rare occurrence. We hereby report two such cases. Two cases of migrated IUCD into urinary bladder and mesoappendix is described here. Both case remained asymptomatic over years and diagnosed incidentally. But IUCD was retrieved in both by surgical means. Owing to possibility of potential complications and medico-legal concerns due to migrated IUCD, it needs to be removed even in asymptomatic cases. [Int J Reprod Contracept Obstet Gynecol 2014; 3(4.000: 1110-1112

Divya Pandey

2014-08-01

191

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...

192

MOLECULAR SPECIATION OF SECONDARY ORGANIC AEROSOL FROM PHOTOOXIDATION OF THE HIGHER ALKENES: 1-OCTENE AND 1-DECENE. (R824970)  

Science.gov (United States)

Outdoor smog chamber photooxidations to determine the molecular composition of secondary organic aerosol (SOA) from 1-octene and 1-decene in sunlight-irradiated hydrocarbon-NO x mixtures are reported. The observed products are consistent with the current under...

193

HYDROCARBONS RESERVES IN VENEZUELA  

Energy Technology Data Exchange (ETDEWEB)

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)

Gonzalez Cruz, D.J.

2007-07-01

194

Evaluation of hydrocarbon potential  

Energy Technology Data Exchange (ETDEWEB)

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.

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

1992-09-30

195

Volatile hydrocarbon detector apparatus  

International Nuclear Information System (INIS)

This invention is a volatile hydrocarbon detector apparatus to continuously sample methane gas in an oil well drilling mud. The detector apparatus includes 1) a gas sampler assembly to gather the methane gas from the drilling mud; 2) a control module assembly to receive and amplify electrical signals from the gas sampler assembly; and 3) a recorder assembly to receive output electrical signals from the control module assembly. The recorder assembly is of a conventional nature and operates to record on a paper roll the date, time of day and the amount of methane gas present in the drilling mud. The main novelty lies in the gas sampler assembly which includes 1) a hood housing assembly to straddle a flowing channel of drilling mud; 2) a sensing head assembly mounted in the hood housing assembly to measure amount of methane gas therein; and 3) a pump assembly operable to draw inlet air through the sensing head assembly and discharge air into the channel of drilling mud. The discharge air acts to agitate the drilling mud to increase release of methane gas therein to transmit a more accurate measurement of the methane gas to the recorder assembly

196

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

197

Hydrocarbon potential of Morocco  

Energy Technology Data Exchange (ETDEWEB)

Morocco lies at the junction of the African and Eurasian plates and carries a record of their movements since the end of the Precambrian. Four structural regions with basins and troughs can be identified: Saharan (Tarfaya-Ayoun and Tindouf basins); Anti-Atlas (Souss and Ouarzazate troughs and Boudnib basin); the Essaouria, Doukkala, Tadla, Missour, High Plateau, and Guercif basins; and Meseta and Rif (Rharb and Pre-Rif basins). The targets in the Tindouf basin are Paleozoic, Cambrian, Ordovician (clastics), Devonian (limestones), and Carboniferous reservoirs sourced primarily by Silurian shales. In the remaining basins, excluding the Rharb, the reservoirs are Triassic detritals, limestones at the base of the Lias and Dogger, Malm detritals, and sandy horizons in the Cretaceous. In addition to the Silurian, potential source rocks include the Carboniferous and Permo-Carboniferous shales and clays; Jurassic shales, marls, and carbonates; and Cretaceous clays. In the Rharb basin, the objectives are sand lenses within the Miocene marls. The maturation level of the organic matter generally corresponds to oil and gas. The traps are stratigraphic (lenses and reefs) and structural (horsts and folds). The seals in the pre-Jurassic rocks are shales and evaporites; in the younger rocks, shales and marl. Hydrocarbon accumulations have been found in Paleozoic, Triassic, Liassic, Malm, and Miocene rocks.

Achnin, H.; Nairn, A.E.M.

1988-08-01

198

Evaluation of hydrocarbon potential  

International Nuclear Information System (INIS)

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 Formationclose 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

199

Feminization of migrations?  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Women have always taken part in migrations, but their presence varied depending on their origins, on the labour market situation both in the areas of origin and in the target areas, as well as the migration policies in the immigration areas. Their presence was not always visible and did not attract as much scholarly and political attention as today. What happened, how can one explain such an interest lately, whereas only few years ago the subject was marginal, in the shadow of the "main...

Morokvaši? Mirjana

2010-01-01

200

The Analysis of International Migration towards Economic Growth  

Directory of Open Access Journals (Sweden)

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.

Ferdous Alam

2011-01-01

 
 
 
 
201

Migration scenarii in extrasolar systems  

Directory of Open Access Journals (Sweden)

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.

Crida A.

2011-02-01

202

Secondary electron emission from diamond surfaces  

International Nuclear Information System (INIS)

Diamond exhibits very high, but widely varying, secondary-electron yields. In this study, we identified some of the factors that govern the secondary-electron yield from diamond by performing comparative studies on polycrystalline films with different dopants (boron or nitrogen), doping concentrations, and surface terminations. The total electron yield as a function of incident-electron energy and the energy distribution of the emitted secondary electrons showed that both bulk properties and surface chemistry are important in the secondary-electron-emission process. The dopant type and doping concentration affect the transport of secondary electrons through the sample bulk, as well as the electrical conductivity needed to replenish the emitted electrons. Surface adsorbates affect the electron transmission at the surface-vacuum interface because they change the vacuum barrier height. The presence of hydrogen termination at the diamond surface, the extent of the hydrogen coverage, and the coadsorption of hydrocarbon-containing species all correlated with significant yield changes. Extraordinarily high secondary-electron yields (as high as 84) were observed on B-doped diamond samples saturated with surface hydrogen. The secondary electrons were predominantly low-energy quasithermalized electrons residing in the bottom of the diamond conduction band. Two key reasons for the unusually high yields are (1) the wide band gap which allows the low-energy secondary electrons to ows the low-energy secondary electrons to have long mean-free paths, and (2) the very low or even negative electron affinity at the surface which permits the low-energy quasithermalized electrons that reach the surface to escape into vacuum

203

Separation and determination of polyaromatic hydrocarbons by capillary electrokinetic chromatography  

International Nuclear Information System (INIS)

Due to the abundance of polyromatic hydrocarbons (PAHs) in environment and the adverse health effects to which they have been linked, these compounds have been the focus of considerable attention in a number of areas including chemical separations. Especially, nowadays due to many advantages of the capillary electrophoresis technique (CE), detection and analyses of these kinds of compounds by using CE have become more important. In order to separate nonionic compounds in CE, an interaction with a charged carrier in the buffer should be provided. Both PAHs can be separated in CE by using additives which cause selectivity change and resolution of PAHs having the same electrophoretic mobility, not only due to electrostatic interaction but also due to a combination of other effects like hydrophobicity, hydrogen bonding, dipole-dipole interaction, etc. Sodium dodecylbenzenesulfonate (SDBS) was evaluated as potential preudo-stationary phase for the separation of highly hydrophobic polycyclic aromatic hydrocarbons (PAHs) with electrokinetic chromatography in aqueous-organic media. PAH molecules undergo a solvophobic interaction with the SDBS ion, forming negatively charged species that can migrate in an elctric field. Thus electrophoretic seperations of 8 PAHs and 3 aromatic compounds having different ring numbers (1-5) were achieved with efficiencies between 130.000-230.000 theoretical plates. Reproducibilities of migration times range between 1.15 and 1.55 % RSD and peak ange between 1.15 and 1.55 % RSD and peak areas between 2 and 9 % RSD

204

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)

205

Migration, a Moving Experience.  

Science.gov (United States)

Discusses the processes involved in migrating a library's automation system. Highlights include getting information from vendor demonstrations, setting up an evaluation database to analyze RFPs (requests for proposals), making a spreadsheet that compares costs of packages, making recommendations once the data are analyzed, and implementation…

Simpson, Carol

1999-01-01

206

Practical Data Migration  

CERN Document Server

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.

Morris, Johny

2012-01-01

207

THE ROMANIAN MIGRATIONAL EVOLUTION PHENOMENON  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In our contemporary democratic society the migration phenomenon meets unknown valences in any previous societies. Free will and right to self-determination, much exploited by the XX century society., raised the possibility of interpretation of migration

Cristian Raluca; Sorlescu Mariana

2009-01-01

208

Radionuclide migration studies in soil  

International Nuclear Information System (INIS)

In this work a brief description about retention and migration parameters of radionuclides in soil, including main methods to determine the distribution coefficient (K) are given. Some of several factors that can act on the migration are also mentioned. (author)

209

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

210

Conceptual design of air sparge/soil vent systems for in situ remediation of petroleum hydrocarbons  

International Nuclear Information System (INIS)

A conceptual design for a sparge and vent system is presented. A sparge and vent system consists of air sparging or in situ aeration in combination with soil vapor extraction. With air sparging, a compressed air source provides sparging of the ground water through aeration points, volatizes dissolved hydrocarbons, and elevates dissolved oxygen (DO) levels in the ground water. Volatile hydrocarbon vapors migrate more readily than liquid in soil, and are extracted to atmosphere with the vapor extraction system. Increased oxygen levels in the ground water and unsaturated soil promotes natural, aerobic biodegradation of the hydrocarbons without nutrient addition. Design considerations for sparge systems include spacing and depth of installation of the sparging points, air injection rates and pressures and the air source. The design techniques for the soil vapor extraction system have been discussed extensively in the literature but generally involve spacing of the extraction wells to capture all the hydrocarbons stripped from the ground water. The soil vapor extraction system can also be modified to enhance oxygen (air) delivery to the unsaturated zone and thus promote natural biodegradation of the petroleum hydrocarbons in the soil. Techniques for monitoring the progress of remediation include measurement of oxygen and carbon dioxide levels in the soil, DO levels in the ground water, subsurface air pressures and petroleum hydrocarbon levels in the discharged air, soil anrbon levels in the discharged air, soil and ground water

211

Experimental approaches in migration studies  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The decision of whether or not to migrate has far-reaching consequences for the lives of individuals and their families. But the very nature of this choice makes identifying the impacts of migration difficult, since it is hard to measure a credible counterfactual of what the person and their household would have been doing had migration not occurred. Migration experiments provide a clear and credible way for identifying this counterfactual, and thereby allowing causal estimation of the impact...

Mckenzie, David; Yang, Dean

2010-01-01

212

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

213

FACTORS AFFECTING INTERNATIONAL LABOR MIGRATION  

Directory of Open Access Journals (Sweden)

Full Text Available  The article reviews the evolution of the main theories that explain the labor migration system impacts on international labor migration are shown. Particular attention is paid to the analysis of external labor migration factors in Ukraine based on the use of the basic tenets of the "push and pull factors" theory.

?.?. ???????

2012-03-01

214

Migration and Citizenship: Normative Debates  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This handbook article distinguishes migration as a boundary crossing phenomenon from mobility as movement in time and space and discusses the normative dilemmas of migration policy from the perspectives of free movement, global distributive justice and democratic citizenship. It concludes by suggesting the political theories need to open up to empirical migration research.

Baubo?ck, Rainer

2012-01-01

215

Organic geochemistry and coal petrology of Tertiary brown coal in the Zhoujing mine, Baise Basin, South China; 3. Characteristics of polycyclic aromatic hydrocarbons  

Energy Technology Data Exchange (ETDEWEB)

The polycyclic aromatic hydrocarbons of the Tertiary brown coal from Zhoujing mine have been characterized in detail. They are composed mainly of aromatic sesqui-, di-, sester- and triterpenoid hydrocarbons, with retene and simonellite as the predominant species. Secondary in abundance are mono- to pentaaromatic triterpenoid hydrocarbons, derived from oleanane, ursane and lupane precursors, indicators of terrestrial sources. Minor species present are a tetraaromatic norhopane, undecyltoluene and perylene and most of the regular polynuclear aromatic hydrocarbons are found at trace levels only. 33 refs., 9 figs., 3 tabs.

Wang, T.-G.; Simoneit, B.R.T. (Jianghan Petroleum Institute, Shashi City (China). Petroleum Geochemistry Unit)

1991-07-01

216

Seminar on the geology and hydrocarbon potential of the Northwest Territories: proceedings  

Energy Technology Data Exchange (ETDEWEB)

Resource potential in the Northwest Territories (NWT) was discussed. Twenty-four significant gas and oil discoveries have been identified in the Western Canada Sedimentary Basin in the mainland portion of the NWT. The four physiographic regions where oil and gas have been discovered were the Liard Plateau, the Great Slave Plain, the Mackenzie Plain, and the Colville Hills. This seminar included eight presentations dealing with the exploration history and drilling density in the NWT. Discovered resources were listed by type. The geology and petroleum potential of the Devonian and Cretaceous strata in the Mackenzie Valley and Northern Interior Plains was discussed, including the geology of the Norman Wells oilfield. A paper was devoted to a discussion of research related to hydrocarbons in the NWT. The research included geochemical investigation to trace the thermal evolution and fluid migration history of sedimentary basins, hydrocarbon maturation studies, fluid migration studies, and modelling of thermochemical sulphate reduction related to reservoir evaluation. 2 tabs., 8 figs.

NONE

1995-10-01

217

The features of the spatial disposition of deposits of hydrocarbons of varying phase state  

Energy Technology Data Exchange (ETDEWEB)

It is shown that the regularities in the distribution of oil, oil and gas condensate and gas condensate deposits in the Jurassic and Cretaceous deposits of the Prikumsko-Tyulenevsk arch in the eastern cis-Caucasus, as well as the regular changes in the physical and chemical properties of the oils, the accompanying gases and condensates are related to the characteristics of the differential trapping of hydrocarbons on their migration paths. The regularities of differential trapping of hydrocarbons in various geological conditions are examined: in identical, regionally dispersed strata with lateral migration along a series of parallel and intersection or joining anticlinal zones, along various regionally dispersed strata of an anticlinal zone; with vertical overflows and the like. The regularities in spatial disposition of the oil and gas deposits are established.

Aleksin, A.G.; Genkin, B.M.

1980-01-01

218

Secondary electron emission from diamond surfaces  

Energy Technology Data Exchange (ETDEWEB)

Diamond exhibits very high, but widely varying, secondary-electron yields. In this study, we identified some of the factors that govern the secondary-electron yield from diamond by performing comparative studies on polycrystalline films with different dopants (boron or nitrogen), doping concentrations, and surface terminations. The total electron yield as a function of incident-electron energy and the energy distribution of the emitted secondary electrons showed that both bulk properties and surface chemistry are important in the secondary-electron-emission process. The dopant type and doping concentration affect the transport of secondary electrons through the sample bulk, as well as the electrical conductivity needed to replenish the emitted electrons. Surface adsorbates affect the electron transmission at the surface-vacuum interface because they change the vacuum barrier height. The presence of hydrogen termination at the diamond surface, the extent of the hydrogen coverage, and the coadsorption of hydrocarbon-containing species all correlated with significant yield changes. Extraordinarily high secondary-electron yields (as high as 84) were observed on B-doped diamond samples saturated with surface hydrogen. The secondary electrons were predominantly low-energy quasithermalized electrons residing in the bottom of the diamond conduction band. Two key reasons for the unusually high yields are (1) the wide band gap which allows the low-energy secondary electrons to have long mean-free paths, and (2) the very low or even negative electron affinity at the surface which permits the low-energy quasithermalized electrons that reach the surface to escape into vacuum.

Shih, A.; Yater, J.; Pehrsson, P.; Butler, J.; Hor, C.; Abrams, R. [Naval Research Laboratory, Washington, DC 20375 (United States)

1997-08-01

219

Geochemical ways of artificial radionuclide migration in biosphere  

International Nuclear Information System (INIS)

This collection presents abstracts of papers on the following subjects: organization and methodology of research and developments on creation of combined medium- and largescale landscape-geochemical and radioecological maps for territories contaminated by radionuclides; typological and space features of distribution of artificial radionuclides and regularities of their migration, the radionuclides being entered the biosphere during accidents at NPPs; forms of artificial radionuclides in biosphere after the NPP accidents; simulation of primary entering and secondary migration of radionuclides in biosphere; methodology of organization and conducting radiogeochemical monitoring of biosphere; new methods and means for radiation monitoring of the environment

220

Enrichment of light hydrocarbon mixture  

Science.gov (United States)

Light hydrocarbon enrichment is accomplished using a vertically oriented distillation column having a plurality of vertically oriented, nonselective micro/mesoporous hollow fibers. Vapor having, for example, both propylene and propane is sent upward through the distillation column in between the hollow fibers. Vapor exits neat the top of the column and is condensed to form a liquid phase that is directed back downward through the lumen of the hollow fibers. As vapor continues to ascend and liquid continues to countercurrently descend, the liquid at the bottom of the column becomes enriched in a higher boiling point, light hydrocarbon (propane, for example) and the vapor at the top becomes enriched in a lower boiling point light hydrocarbon (propylene, for example). The hollow fiber becomes wetted with liquid during the process.

Yang, Dali (Los Alamos, NM); Devlin, David (Santa Fe, NM); Barbero, Robert S. (Santa Cruz, NM); Carrera, Martin E. (Naperville, IL); Colling, Craig W. (Warrenville, IL)

2011-11-29

 
 
 
 
221

Hydrocarbon components in carbonaceous meteorites  

Science.gov (United States)

Currently, the presence of free n-alkanes and isoprenoid alkanes in carbonaceous meteorites is usually explained either by microbial contamination during the period between the meteorite fall and collection or by contamination from the environment of analytical laboratories and museums. The goal of this research was to repeat analysis of hydrocarbon components in meteorites and to investigate possible meteorite contamination routes discussed in the literature. Experimental analysis of free organic constituents in five carbonaceous meteorites by infrared spectroscopy (IR) and gas chromatographic (GC) methods confirmed the presence of extractable aliphatic components, n-alkanes in the C 15H 32-C 27H 56 range and isoprenoid alkanes (phytane, pristane, and norpristane), in some of these meteorites. The contents of these compounds vary depending on the source. Insoluble organic components of two meteorites (meteorite kerogens) were isolated, and their composition was analyzed by IR and cracking/GC methods. Comparison with the data on several terrestrial contamination sources proposed in the literature shows that the presence of free saturated hydrocarbons in meteorites and the composition of the meteorite kerogen could not be explained either by microbial contamination or by contamination from the laboratory environment. The types of the hydrocarbons in meteorites resemble those typical of ancient terrestrial deposits of organic-rich sediments, except for the absence of lighter hydrocarbons, which apparently slowly evaporated in space, and multi-ring naphthenic compounds of the biologic origin, steranes, terpanes, etc. The prevailing current explanation for the presence of free linear saturated hydrocarbons in carbonaceous meteorites, apart from contamination, is the abiotic route from hydrogen and carbon monoxide. However, the data on the structure of meteorite kerogens require a search for different routes that initially produce complex polymeric structures containing n-alkyl and isoprenoid chains which are attached, via polar links (esters, salts, etc.), to a cross-linked polymer matrix. Later, the polymer slowly decomposes with the liberation of free aliphatic hydrocarbons.

Kissin, Y. V.

2003-05-01

222

Durability of fluorinated high density polyethylene (F-HDPE) geomembrane exposed to hydrocarbons in the Arctic  

Energy Technology Data Exchange (ETDEWEB)

A hydrocarbon spill in the Canadian Arctic has been controlled with a geosynthetic clay liner (GCL) composed of a fluorinated high-density polyethylene (f-HDPE) geomembrane. The liner controlled the advective and diffusive migration of the hydrocarbons. This study examined the antioxidant depletion and the compatibility of both untreated and fluorinated high density polyethylene (HDPE) geomembranes with hydrocarbons. The objective was to determine the durability and long term performance of the HDPE geomembrane. Geomembrane swatches retrieved from the field site were examined for changes in oxidative induction time, crystallinity, tensile properties and dimensions. Laboratory results revealed that the properties of the buried 1.5 mm thick f-HDPE geomembranes have not been significantly altered since installation. The durability of the f-HDPE geomembrane was maintained for more than the designed service life of the liner. 26 refs., 1 tab., 8 figs.

Rimal, S.; Rowe, R.K.; Bathurst, R.J. [Queen' s Univ., Kingston, ON (Canada). Dept. of Civil Engineering, Geoengineering Centre

2007-07-01

223

Biological enhancement of hydrocarbon extraction  

Science.gov (United States)

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.

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

2009-01-06

224

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

Science.gov (United States)

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.

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

2012-12-01

225

Prediction of cold start hydrocarbon emissions of air cooled two wheeler spark ignition engines by simple fuzzy logic simulation  

Directory of Open Access Journals (Sweden)

Full Text Available The cold start hydrocarbon emission from the increasing population of two wheelers in countries like India is one of the research issues to be addressed. This work describes the prediction of cold start hydrocarbon emissions from air cooled spark ignition engines through fuzzy logic technique. Hydrocarbon emissions were experimentally measured from test engines of different cubic capacity, at different lubricating oil temperature and at different idling speeds with and without secondary air supply in exhaust. The experimental data were used as input for modeling average hydrocarbon emissions for 180 seconds counted from cold start and warm start of gasoline bike engines. In fuzzy logic simulation, member functions were assigned for input variables (cubic capacity and idling rpm and output variables (average hydrocarbon emission for first 180 seconds at cold start and warm start. The knowledge based rules were adopted from the analyzed experimental data and separate simulations were carried out for predicting hydrocarbon emissions from engines equipped with and without secondary air supply. The simulation yielded the average hydrocarbon emissions of air cooled gasoline engine for a set of given input data with accuracy over 90%.

Samuel Raja Ayyanan

2014-01-01

226

Governance in Nurse Migration  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The thrust of this study is anchored on the questions: "What are the underlying factors supportive of good governance and how are they pursued as growth strategy during 1999 to 2008?" To what extent has good governance benefited the country in nurse migration during this ten-year period? In addressing this question, textual data and information were gathered from various documents and communications (memoranda, circulars, bulletins, transcripts, publications and others) of five (5) participat...

Cirujales, S. Ma Remegia M.; Kuan, Letty G.

2012-01-01

227

Pathologic tooth migration.  

Science.gov (United States)

Pathologic tooth migration (PTM) is a common complication of moderate to severe periodontitis and is often the motivation for patients to seek periodontal therapy. In this review of the literature, available information concerning prevalence, etiology, treatment, and prevention of pathologic tooth migration is summarized. Prevalence of PTM among periodontal patients has been reported to range from 30.03% to 55.8%. A survey of the literature regarding chief complaints of periodontal patients support these high prevalence findings. The etiology of PTM appears to be multifactorial. Periodontal bone loss appears to be a major factor in the etiology of PTM. Many aspects of occlusion can contribute to abnormal migration of teeth, and more than one of those factors may be present in an individual patient. Soft tissue forces of the tongue, cheeks, and lips are known to cause tooth movement and in some situations can cause PTM. Also considered important in the etiology of PTM is pressure produced from inflammatory tissues within periodontal pockets. Because extrusion is a common form of PTM, clinical observations support the theory that eruption forces sometimes play a role in the etiology of PTM. Many oral habits have been associated with PTM which are often difficult for the therapist to detect. Most cases of severe PTM require a team approach to achieve success. Periodontal, orthodontic, and prosthodontic treatment are often required. Many patient variables enter into the selection of treatment for PTM. In early stages of PTM, spontaneous correction of migrated teeth sometimes occurs after periodontal therapy. Light intrusive forces are used successfully to treat extrusion and flaring forms of PTM. Based on the literature reviewed, it appears that many cases of PTM could be prevented through the early diagnosis and treatment of periodontal disease, occlusal contributing factors, gingival enlargement, and oral habits. PMID:15948679

Brunsvold, Michael A

2005-06-01

228

FUNGI AND HYDROCARBONS IN THE MARINE ENVIRONMENT  

Science.gov (United States)

Hydrocarbons from various sources--anthropogenic pollution, marine seeps, marine algae, atmospheric fallout and terrestrial runoff--enter the ocean daily. These complex hydrocarbon mixtures are dispersed and degraded by abiotic and biogenic processes. Most commonly, bacteria are ...

229

Mechanism of methanol conversion to hydrocarbons over HZSM-5  

International Nuclear Information System (INIS)

Studies of methanol conversion over HZSM-5 using 13C-labeled methanol in the presence of various olefins and aromatics revealed the importance of desorption limitation of reaction intermediates, as evidenced by extensive multiple labeling of polymethylbenzenes produced from unlabeled toluene. These studies also indicated that most of the ethylene produced from methanol is not a primary C1 coupling product, but rather a secondary product derived from methyl attack on C3+ olefins, as evidenced by the predominant formation of singly labeled ethylene. A classical carbenium ion mechanism incorporating these findings is presented for the conversion of methanol to hydrocarbons over HZSM-5

230

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.

231

Ambient aromatic hydrocarbon measurements at Welgegund, South Africa  

Science.gov (United States)

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.

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

232

Migration and degradation of fuel vapours in the vadose zone. Field experiment at airbase Værløse  

DEFF Research Database (Denmark)

Fuel has been spilled in the vadose zone at many sites. An artificial jet fuel source has been installed in a vadose zone (3.5 m sand) at Airbase Værløse. The field experiment is conducted to investigate the natural attenuation potential in order to obtain better evaluations of the risk for ground water contamination. The migration of the hydrocarbon vapours has been monitored intensively together with the hydrocarbon concentrations in the pore water and the groundwater. The results so far indicate that for most of the compounds degradation is significantly decreasing the concentrations. Therefore, natural attentuation as a remediation technology appears promising.

Christophersen, Mette; Broholm, Mette Martina

2002-01-01

233

Steam Hydrocarbon Cracking and Reforming  

Science.gov (United States)

The interactive methods of steam hydrocarbon reforming and cracking of the oil and chemical industries are scrutinized, with special focus on their resemblance and variations. The two methods are illustrations of equilibrium-controlled and kinetically-controlled processes, the analysis of which involves theories, which overlap and balance each…

Golombok, Michael

2004-01-01

234

Study of migration behavior of technogenic radionuclides in the Yenisey River-Kara Sea aquatic system  

International Nuclear Information System (INIS)

For 35 years Krasnoyarsk Mining-Chemical Combine (MCC) manufactures weapon plutonium in single-pass production reactors cooled with water of the Yenisey River. Water discharge from these reactors is the major source of radioactive contamination of the Yenisey River. We have demonstrated that after putting the reactors out of operation (in late 1992) the contamination level of the Yenisey River with short-lived radionuclides considerably decreased, and now the radioactive contamination is caused essentially by Cs-137, Eu-152, Pu-239,240, Sr-90, and Am-241, whose concentration in the aqueous phase is lower than in bottom sediments and, particularly, flood-land deposits by several orders of magnitude (except for Sr-90). The flood-land deposits are classified with the most contaminated environmental objects in the territories under the impact of MCC: their radioactivity is comparable with that of low-level waste. Taking into account the considerable depth and area of the flood-land deposits, this allows their classification as a great technogenic radiation anomaly. Comparison of the maximal Cs-137 and Pu-239,240 levels in flood-land soils and bottom sediments of the Yenisey River with those in bottom sediments of the Pripyat' River and the Kiev reservoir shows that these values are close each to other. A direct correlation is found between the spatial distribution of Cs-137 on the one hand and Pu-239,240, Eu-152, and Am-241 on the other hand in the aqueous phase and bottom sediments, which is not the case for Sr-90. Data on the distribution coefficients of the indicated radionuclides between the deposits and aqueous phase (obtained with actual and model systems) and also on the radionuclide distribution throughout geochemical mobility forms suggest that the essential part of Cs, Pu, Eu, and Am migrates with fine-disperse suspended material, the transport and distribution of which is controlled by the hydrological regime of the Yenisey River. By contrast, strontium migrates as soluble species weakly sorbed by the solid phase, causing the observed low content of Sr-90 in flood-land deposits and bottom sediments of the Yenisey River. The indicated migration behavior of radionuclides is characteristic of the Yenisey Gulf and the adjacent part of the Kara Sea also. We made similar conclusions when studying the migration behavior of Cs-137, Pu-239,240, and Sr-90 in the Kiev reservoir (1987). The formation of radioactive flood-land deposits is provided by rapid deposition of suspended material in stagnant zones during periodical flood. Humus compounds contribute significantly to accumulation of radionuclides in the flood-land deposits and bottom sediments, which is supported by the observed correlation between the radionuclide (Pu, Am, Eu) and total organic carbon distributions in them. Radiochemical analysis of separate fractions showed that about 20% of Pu and Am are associated with the organic fraction: Pu is nearly equally distributed between humic and fulvic acid fractions, whereas Am is preferentially associated with the fulvic acid fraction (the most mobile fraction of humus matter). It was demonstrated in model experiments that the calcium-hydrocarbonate type of water of the Yenisey River causes suppression of formation of mobile fulvate complexes of hydrolyzable radionuclides and, therefore, their transfer into the aqueous phase. In combination with the observed very high distribution coefficients of the radionuclides and low content of their mobile geochemical forms in flood-land deposits of the Yenisey River this suggest that they cannot contribute somewhat significantly to the secondary radioactive contamination of the river water by all mechanisms except migration by mechanical transfer. (author)

235

Optimizing Total Migration Time in Virtual Machine Live Migration  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 ...

Gustafsson, Erik

2013-01-01

236

Biodegradation of petroleum hydrocarbons in hypersaline environments  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english 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.

Luiz Fernando, Martins; Raquel Silva, Peixoto.

2012-09-01

237

Syngas Upgrading to Hydrocarbon Fuels Technology Pathway  

Energy Technology Data Exchange (ETDEWEB)

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.

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

2013-03-01

238

Population, desertification, and migration.  

Science.gov (United States)

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

Westing, A H

1994-01-01

239

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)

240

Analysis of siloxanes in hydrocarbon mixtures using comprehensive two-dimensional gas chromatography.  

Science.gov (United States)

A comprehensive two-dimensional gas chromatography (GC×GC) method for separating siloxanes from hydrocarbons has been developed using a systematic process. First, the retention indices of a set of siloxanes and a set of hydrocarbons were determined on 6 different stationary phases. The retention indices were then used to model GC×GC separation on 15 different stationary phase pairs. The SPB-Octyl×DB-1 pair was predicted to provide the best separation of the siloxanes from the hydrocarbons. The efficacy of this stationary phase pair was experimentally tested by performing a GC×GC analysis of gasoline spiked with siloxanes and by analyzing biogas obtained from a local wastewater treatment facility. The model predictions agreed well with the experimental results. The SPB-Octyl×DB-1 stationary phase pair constrained the hydrocarbons to a narrow range of secondary retention times and fully isolated the siloxanes from the hydrocarbon band. The resulting GC×GC method allows siloxanes to be resolved from complex mixtures of hydrocarbons without requiring the use of a selective detector. PMID:25087744

Ghosh, Abhijit; Seeley, Stacy K; Nartker, Steven R; Seeley, John V

2014-09-19

 
 
 
 
241

Migration and loving  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

Gevrek, Deniz

2010-01-01

242

Climate and Human Migrations  

Science.gov (United States)

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.

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

2002-10-25

243

Diagenesis of hydrocarbon-bearing rocks in the Middle Ordovician Simpson Group, southeastern Anadarko Basin, Oklahoma  

Science.gov (United States)

Quartzarenites and subarkoses in the Middle Ordovician Simpson Group in the Gulf Costello No. 1 and Sunray-DX Parker No. 1 Mazur wells, southeastern Anadarko basin, have undergone a complex diagenetic and petroleum-migration history. During early burial, petroleum migrated locally through sandstones; patches of bitumen in calcite and bitumen-lined quartz overgrowths containing oil-bearing inclusions reflect the introduction of petroleum-bearing fluids at shallow depths. Stable-isotope data reveal that early calcite precipitated at near-surface temperatures from fluids dominated by marine carbon. At moderate to deep burial, calcite dissolution, followed by ferroan-dolomite and clay-mineral precipitation, occurred at about the same time as the rocks reached levels of thermal maturity sufficient for the generation of hydrocarbons. Maximum paleotemperatures during deep burial are estimated from maturation models to have reached 250°F in the Costello well and 300°F in the Mazur well. Maturation-derived temperatures in the Costello well are consistent with preliminary homogenization temperatures (210-250°F) for oil inclusions along microscopic healed fractures that formed during deep burial, thus supporting an Early to Middle Pennsylvanian timing for the generation and migration of late-stage hydrocarbons. The early petroleum phase, emplaced while the rocks were at shallow burial depths, migrated from mature source rocks deeper in the basin.

Pitman, Janet K.; Burruss, Robert C.

1989-01-01

244

Tolerance of Antarctic soil fungi to hydrocarbons  

Energy Technology Data Exchange (ETDEWEB)

Little is known about the effects of hydrocarbons and fuel oil on Antarctic filamentous fungi in the terrestrial Antarctic environment. Growth of fungi and bacteria from soils around Rothera Research Station (Adelaide Island, Antarctic Peninsula) was assessed in the presence of ten separate aromatic and aliphatic hydrocarbons [marine gas oil (MGO), dodecane, hexadecane, benzoic acid, p-hydroxybenzoic acid, toluene, phenol, biphenyl, naphthalene and m- and p-xylenes with ethylbenzene]. Aromatic hydrocarbons inhibited soil microbial growth more than aliphatic hydrocarbons. Soil microorganisms from a moss patch, where little previous impact or hydrocarbon contamination had occurred, were less tolerant of hydrocarbons than those from high impact sites. Fungal growth rates of Mollisia sp., Penicillium commune, Mortierella sp., Trichoderma koningii, Trichoderma sp. and Phoma herbarum were assessed in the presence of hydrocarbons. Generally, aromatic hydrocarbons inhibited or stopped hyphal extension, though growth rates increased with some aliphatic hydrocarbons. Hyphal dry weight measurements suggested that Mortierella sp. may be able to use dodecane as sole carbon and energy source. Hydrocarbon-degrading Antarctic fungi may have use in future hydrocarbon spill bioremediation. (author)

Hughes, Kevin A.; Bridge, Paul; Clark, Melody S. [British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge CB3 0ET (United Kingdom)

2007-01-01

245

Tolerance of Antarctic soil fungi to hydrocarbons.  

Science.gov (United States)

Little is known about the effects of hydrocarbons and fuel oil on Antarctic filamentous fungi in the terrestrial Antarctic environment. Growth of fungi and bacteria from soils around Rothera Research Station (Adelaide Island, Antarctic Peninsula) was assessed in the presence of ten separate aromatic and aliphatic hydrocarbons [marine gas oil (MGO), dodecane, hexadecane, benzoic acid, p-hydroxybenzoic acid, toluene, phenol, biphenyl, naphthalene and m- and p-xylenes with ethylbenzene]. Aromatic hydrocarbons inhibited soil microbial growth more than aliphatic hydrocarbons. Soil microorganisms from a moss patch, where little previous impact or hydrocarbon contamination had occurred, were less tolerant of hydrocarbons than those from high impact sites. Fungal growth rates of Mollisia sp., Penicillium commune, Mortierella sp., Trichoderma koningii, Trichoderma sp. and Phoma herbarum were assessed in the presence of hydrocarbons. Generally, aromatic hydrocarbons inhibited or stopped hyphal extension, though growth rates increased with some aliphatic hydrocarbons. Hyphal dry weight measurements suggested that Mortierella sp. may be able to use dodecane as sole carbon and energy source. Hydrocarbon-degrading Antarctic fungi may have use in future hydrocarbon spill bioremediation. PMID:17157897

Hughes, Kevin A; Bridge, Paul; Clark, Melody S

2007-01-01

246

Testing oil saturation distribution in migration paths using MRI  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Magnetic Resonance Imaging (MRI) method allows to observe the distribution of different fluids in situ in porous media, and to measure oil and water saturation. Although this technique has great advantages compared to others, there remains large space for assessing the method and improving the accuracy of measurement. Using MRI, the oil secondary migration paths are scanned to measure the saturation distribution during the laboratory experiments. The resulting map can be calibrated using a de...

Yan, Jianzhao; Xiaorong, Luo; Wang, Weimin; Chen, Fang; Toussaint, Renaud; Schmittbuhl, Jean; Vasseur, Guy; Zhang, Likuan

2012-01-01

247

[Secondary glomerular nephropathies].  

Science.gov (United States)

Secondary glomerular lesions are associated with various diseases; diabetes, systemic lupus erythematosus, primary cryoglobulinaemia, cryoglobulinemia and membranoproliferative glomerulonephritis secondary to hepatitis C virus (HCV), ANCA associated vasculitis and their forms limited to kidney (necrotic and crescentic GN), Goodpasture syndrome, HIV associated nephropathies, AL amyloidosis, AA amyloidosis (secondary amyloidosis), GN with non-amyloid organised deposits. PMID:15008219

Lesavre, Philippe

2003-11-30

248

The challenges of managing migration  

Energy Technology Data Exchange (ETDEWEB)

Migration and urbanisation are driven by economic growth and social change, but also by deepening inequalities. Managing migration should not be equated with curbing it, as this inevitably reduces migrants' rights. But managing population movement whilst respecting the rights of migrants and nonmigrants, supporting the contribution of migration to poverty reduction and economic growth in sending and receiving areas and reducing the human and material costs of movement means that fundamental challenges need to be addressed.

Tacoli, Cecilia

2005-10-15

249

Nuclear Migration During Retinal Development  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this review we focus on the mechanisms, regulation, and cellular consequences of nuclear migration in the developing retina. In the nervous system, nuclear migration is prominent during both proliferative and post-mitotic phases of development. Interkinetic nuclear migration is the process where the nucleus oscillates from the apical to basal surfaces in proliferative neuroepithelia. Proliferative nuclear movement occurs in step with the cell cycle, with M-phase being confined to the apica...

Baye, Lisa M.; Link, Brian A.

2007-01-01

250

Potential East-West Migration  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Examines the migration potential in the Czech Republic, Hungary, Poland, & Slovakia, using 1996 survey data from 4,392 persons. Results indicate that all scenarios that predict an imminent exodus of people from East & Central Europe are exaggerating the real dimension of East-West migration. The migration potential in the four countries investigated here is between 700,000 & (potentially) 4 million persons, higher than the numbers foreseen by the law for annual immigration to Austria & the Fe...

Hintermann, Christiane; Fassmann, Heinz

1998-01-01

251

Verfahren zur Migration einer Softwarekomponente  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The method involves determining (110) running time request of software component (102). The resources required for migration of software component are determined (112) based on running time requests. The point of time to which determined resources for migration of software component of hardware platform (104-1) are obtained on objective hardware platform is determined (114). The software component of hardware platform is migrated (116) on objective hardware platform at predetermined point of ...

Zeller, M.; Prehofer, C.

2011-01-01

252

Low permeability Neogene lithofacies in Northern Croatia as potential unconventional hydrocarbon reservoirs  

Science.gov (United States)

We present two examples of describing low permeability Neogene clastic lithofacies to outline unconventional hydrocarbon lithofacies. Both examples were selected from the Drava Depression, the largest macrostructure of the Pannonian Basin System located in Croatia. The first example is the Beni?anci Field, the largest Croatian hydrocarbon reservoir discovered in Badenian coarse-grained clastics that consists mostly of breccia. The definition of low permeability lithofacies is related to the margins of the existing reservoir, where the reservoir lithology changed into a transitional one, which is mainly depicted by the marlitic sandstones. However, calculation of the POS (probability of success of new hydrocarbons) shows critical geological categories where probabilities are lower than those in the viable reservoir with proven reserves. Potential new hydrocarbon volumes are located in the structural margins, along the oil-water contact, with a POS of 9.375%. These potential reserves in those areas can be classified as probable. A second example was the Cremušina Structure, where a hydrocarbon reservoir was not proven, but where the entire structure has been transferred onto regional migration pathways. The Lower Pontian lithology is described from well logs as fine-grained sandstones with large sections of silty or marly clastics. As a result, the average porosity is low for conventional reservoir classification (10.57%). However, it is still an interesting case for consideration as a potentially unconventional reservoir, such as the "tight" sandstones.

Malvi?, Tomislav; Su?i?, Antonija; Cvetkovi?, Marko; Resanovi?, Filip; Veli?, Josipa

2014-06-01

253

Effect of biochar on the fate of volatile petroleum hydrocarbons in an aerobic sandy soil  

Science.gov (United States)

Biochar addition to soil is currently being investigated as a novel technology to remediate polluted sites. A critical consideration is the impact of biochar on the intrinsic microbial pollutant degradation, in particular at sites polluted with a mixture of readily biodegradable and more persistent organic pollutants. We therefore studied the impact of biochar (2% on dry weight basis) on the fate of volatile petroleum hydrocarbons in an aerobic sandy soil with batch and column studies. The soil-water partitioning coefficient, K d, was enhanced in the biochar-amended soil up to a factor 36, and petroleum hydrocarbon vapor migration was retarded accordingly. Despite increased sorption, in particular of monoaromatic hydrocarbons, the overall microbial respiration was comparable in the biochar-amended and unamended soil. This was due to more rapid biodegradation of linear, cyclic and branched alkanes in the biochar amended soil. We concluded that the total petroleum hydrocarbon degradation rate was controlled by a factor other than substrate availability and the reduced availability of monoaromatic hydrocarbons in the biochar amended soil led to greater biodegradation of the other petroleum compounds.

Bushnaf, Khaled M.; Puricelli, Sara; Saponaro, Sabrina; Werner, David

2011-11-01

254

Process for recovering hydrocarbons from hydrocarbon-containing biomass  

Energy Technology Data Exchange (ETDEWEB)

A process is disclosed for enzymatically converting whole plant biomass containing hydrocarbon-containing laticifers to soluble sugars and recovering hydrocarbons in increased yields. The process comprises hydrolyzing whole plant cellulosic material in the presence of enzymes, particularly cellulase, hemicellulase, and pectinase, to produce a hydrocarbon product and recovering from the hydrolysis products a major proportion of the cellulase, hemicellulase and pectinase enzymes for reuse. At least some portion of the required make-up of cellulase, hemicellulase and pectinase enzymes is produced in a two-stage operation wherein, in the first stage, a portion of the output sugar solution is used to grow enzyme secreting microorganisms selected from the group consisting of cellulase-secreting microorganisms, hemicellulase-secreting microorganisms, pectinase-secreting microorganisms, and mixtures thereof, and in the second stage, cellulase, hemicellulase and pectinase enzyme formation is induced in the microorganism-containing culture medium by the addition of an appropriate inducer such as biomass. The cellulase, hemicellulase and pectinase enzymes are then recycled for use in the hydrolysis reaction.

Dzadzic, P.M.; Price, M.C.; Shih, C.J.; Weil, T.A.

1982-07-06

255

Mécanismes de migration des radionucléides d'un stockage de déchets radioactifs dans l'argile vers la surface  

Science.gov (United States)

This article is a critical review of the current understanding of migration processes of solutes in clay. The major migration mechanisms are examined: advection through compaction, thermal convection, migration by hydrocarbon expulsion, gravitational flow, osmosis, molecular diffusion, hydrodynamic dispersion. Examples are taken from the Callovo-Oxfordian clays of the Paris basin in the Meuse/Haute Marne area, near Bure, where France is studying the feasibility of a potential nuclear waste disposal facility. Recent work on the helium distribution in the aquifers of the Paris Basin confirms the importance of molecular diffusion for solute transport in clays. Migration in aquifers is also described, and the major causes of uncertainties for solute migration are discussed. To cite this article: G. de Marsily et al., C. R. Physique 3 (2002) 945-959.

de Marsily, Ghislain; Gonçalvès, Julio; Violette, Sophie; Castro, Maria-Clara

2002-10-01

256

Macrostabilization of the Migration Phenomenon  

Directory of Open Access Journals (Sweden)

Full Text Available 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, employment in Romania and Romanian migration towards the countries of Western Europe. It also presents statistics on labor migration in the EU and its impact on the labor market

Cristina Burghelea

2014-03-01

257

Europe: Migration and Development  

Scientific Electronic Library Online (English)

Full Text Available SciELO Mexico | Language: English Abstract in spanish La actitud de los gobiernos hacia la migración -interna y externa- ha cambiado en forma radical en años recientes. Considerada anteriormente como evidencia de una descomposición crónica social y económica así como una seria amenaza para el poder gubernamental (bajo una urbanización acelerada), la mi [...] gración interna es vista actualmente como un mecanismo muy importante para la redistribución de recursos de las localidades más ricas hacia las más pobres y un medio vital para elevar el ingreso de la población de estas áreas. El mismo cambio de percepción se está presentando sobre la migración internacional. En este caso, los flujos de remesas de trabajadores que laboran en el exterior hacia sus familias en sus lugares de origen se han convertido en un componente relevante en el ingreso de divisas de un gran número de países. Al cabo de ciertas reticencias, los gobiernos ahora han venido aceptando la migración por trabajo, con el fin de facilitar y reforzar sus efectos sobre la paliación de la pobreza. Sin embargo, se presentan algunos problemas con la pérdida de los trabajadores más emprendedores y con mayor calificación en los países en desarrollo. ¿Pueden reconciliarse los intereses en juego -países en desarrollo, migrantes, países desarrollados-?. La migración temporal circulatoria con propósitos de capacitación parecería ser el mejor resultado, de tal manera que la migración se convirtiera en un medio para potenciar el capital humano de los países en desarrollo en la tarea de reducir la pobreza mundial. Existen, no obstante, muchas opciones sin inmigración para los países desarrollados, desde reformas a sus mercados laborales internos hasta la subcontratación en el exterior. La alternativa real tiene que ver con la clase de mundo que deseamos. Abstract in english Government attitudes to migration -internal and external- have changed radically in recent years. Formerly seen as evidence of chronic social and economic breakdown and major threats to government power (in accelerated urbanisation), internal migration is now seen as major mechanism for the redistri [...] bution of resources from richer to poorer localities and a vital means of raising the incomes of the poor. The same revision of view is affecting international migration. Here remittance flows from workers working abroad to their families at home have become major components in the foreign exchange earnings of a number of countries. After some reluctance, governments have come to embrace emigration for work, to facilitate and reinforce its effects on the alleviation of poverty. However, there are problems in the loss of the most enterprising and best-trained workers of developing countries. Can the interests at stake -developing countries, migrants, developed countries- be reconciled? Temporary circulatory migration for the purposes of training would seem to be the best outcome, so that migration becomes a means to enhance the human capital of developing countries for the task of reducing world poverty. There are, however, many options for developed countries without immigration - from the reform of their domestic labour markets to off-shoring. The real choice is about what sort of world we want.

Harris, Nigel.

2006-06-01

258

Numerical Simulation of Petroleum Generation and Migration in the Song Hong Basin, Vietnam  

Science.gov (United States)

The numerical modeling of petroleum systems is an effective tool to understand generation, migration and accumulation of hydrocarbons in a sedimentary basin and hence to determine future targets for the hydrocarbon exploration. The numerical modeling identifies two petroleum systems in the Song Hong Basin, which is a petroliferous Cenozoic basin, offshore eastern Vietnam. These petroleum systems were named DinhCao-PhuCu(.) Petroleum System and SongHuong-BienDong(.) Petroleum System. DinhCao-PhuCu(.) Petroleum System covers northern and central parts of the Song Hong basin with Oligocene shale and coaly shale source rocks of Dinh Cao formation, which are dominated by type II-III kerogens. The hydrocarbon generation starts at 13 Ma within deeply buried Oligocene strata located in the centre of the basin. The hydrocarbon expels from the Oligocene source rock and migrates laterally and then up dip toward marginal areas where Middle Miocene sandstones of Phu Cu formation are present as major reservoirs. The numerical model shows that the critical moment occurs at about 3.5 Ma. The DinhCao-PhuCu(.) petroleum system is confirmed by sparse occurrence of oil and gas along the coast of eastern Vietnam. SongHuong-BienDong(.) Petroleum System is identified in limited areas of the central and southern Song Hong basin. The major source rock of this petroleum system is Lower Miocene dark claystones of Song Huong formation which contain gas prone, type III kerogen. The migration model shows that hydrocarbons are generated from the Miocene source rocks in the center of the basin at about 12 Ma, and migrates updip through sand bodies of Quang Ngai formation to the major boundaries faults, and further moves into highly permeable up-dipping units, the Bien Dong formation. The best depiction of the generation-migration-accumulation of hydrocarbons occurs at about 2 Ma. The presence of the SongHuong-BienDong(.) Petroleum System is indicated by the large gas fields in the central and southern Song Hong Basin.

Son, Byeong-Kook; Thi Nguyen, Hong; Park, Mee-Sook

2014-05-01

259

Ambient aromatic hydrocarbon measurements at Welgegund, South Africa  

Directory of Open Access Journals (Sweden)

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.

K. Jaars

2014-02-01

260

Dry reforming of hydrocarbon feedstocks  

Energy Technology Data Exchange (ETDEWEB)

Developments in catalyst technology for the dry reforming of hydrocarbon feedstocks are reviewed for methane, higher hydrocarbons and alcohols. Thermodynamics, mechanisms and the kinetics of dry reforming are also reviewed. The literature on Ni catalysts, bi-metallic Ni catalysts and the role of promoters on Ni catalysts is critically evaluated. The use of noble and transitional metal catalysts for dry reforming is discussed. The application of solid oxide and metal carbide catalysts to dry reforming is also evaluated. Finally, various mechanisms for catalyst deactivation are assessed. This review also examines the various process related issues associated with dry reforming such as its application and heat optimization. Novel approaches such as supercritical dry reforming and microwave assisted dry reforming are briefly expanded upon.

Shah, Yatish T. [Norfolk State University; Gardner, Todd H. [U.S. DOE

2014-01-01

 
 
 
 
261

Proceedings of hydrocarbon contaminated soils  

International Nuclear Information System (INIS)

While the 1980s witnessed a concentrated effort toward identifying the scientific concerns associated with hydrocarbon contaminated soils, the 1990s offer the hope that even more reliable solutions, both scientific and regulatory, will emerge. The hope for this transition from problem identification to problems solution is evident in these papers from the 5th Annual Conference on Hydrocarbon Contaminated Soils (formerly called Petroleum Contaminated Soils), as the presentations more clearly reflect the maturation of a rapidly evolving field in the areas of chemical analysis, fate, remediation, public health, and regulatory evaluation. This book attempts to address the multidimensional facets of soil contamination by providing various current general perspectives as well as those from the regulatory and the international communities. Technical information is also provided in specific contamination areas such as diesel fuel, as well as analysis and site assessment, remediation, risk assessment, and management

262

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

Science.gov (United States)

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

Ghavidel, Ali

2015-01-01

263

Chronic kidney disease after vesico-vaginal stone formation around a migrated intrauterine device.  

Science.gov (United States)

Although the intrauterine device (IUD) seems a reliable and relatively safe method of contraception, it may cause serious complications. A rare complication is uterus perforation. Intravesical migration and secondary calculus formation is exceptionally uncommon. The authors report on a 75-year-old woman in whom a 'forgotten' migrated IUD resulted in vesico-vaginal fistula formation and chronic kidney disease, 39 years after insertion. PMID:22767627

Karsmakers, R; Weis-Potters, A E; Buijs, Guido; Joustra, E B

2010-01-01

264

Chronic kidney disease after vesico-vaginal stone formation around a migrated intrauterine device  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Although the intrauterine device (IUD) seems a reliable and relatively safe method of contraception, it may cause serious complications. A rare complication is uterus perforation. Intravesical migration and secondary calculus formation is exceptionally uncommon. The authors report on a 75-year-old woman in whom a ‘forgotten’ migrated IUD resulted in vesico-vaginal fistula formation and chronic kidney disease, 39 years after insertion.

Karsmakers, R.; Weis-potters, A. E.; Buijs, Guido; Joustra, E. B.

2010-01-01

265

Role of natural attenuation, phytoremediation and hybrid technologies in the remediation of a refinery soil with old/recent petroleum hydrocarbons contamination.  

Science.gov (United States)

Within a search for a biological remediation technology to remove petroleum hydrocarbons (PHC) from a contaminated soil from a refinery, the potential of monitored natural attenuation (MNA) was compared with the use of transplants of Cortaderia selloana both in the absence and in the presence of soil amendments. After 31 months of experiments, MNA was effective in removing most of the recent PHC contamination (50% of the initial total contamination) at 5-20 cm depth. The presence of weathered contamination explains the existence of an established community of PHC degraders, as can be inferred by the most probable number technique. C. selloana, in its turn, showed capacity to mobilize the most recalcitrant fraction of PHC to its roots, nevertheless masking its remediation capacity. The use of a hybrid technology (C. selloana together with treatments with a surfactant and a bioaugmentation product) improved the removal of PHC at 15-20 cm depth, the presence of C. selloana facilitating the migration of additives into the deeper layers of soil, which can be considered a secondary but positive role of the plant. In the surface soil layer, which was exposed to both microorganisms and the atmosphere, a further 20% of weathered PHC contamination disappeared (70% total removal) as a result of photo- and chemical degradation. Periodic revolving of the soil, like tillage, to expose all the contaminated soil to the atmosphere will therefore be a reliable option for reducing the contamination of the refinery soil if conditions (space and equipment) permit this operation. PMID:23240204

Couto, Maria Nazaré P F S; Pinto, Dorabela; Basto, M Clara P; Vasconcelos, Teresa S D

2012-09-01

266

Catalytic method for synthesizing hydrocarbons  

Science.gov (United States)

A method for synthesizing hydrocarbons from carbon monoxide and hydrogen by contacting said gases with a slurry of a catalyst composed of palladium or platinum and cobalt supported on a solid phase is disclosed. The catalyst is prepared by heating a heterogeneous component of the palladium or platinum deposited on the solid support in a solution of cobalt carbonyl or precursors thereof. The catalyst exhibits excellent activity, stability in air, and produces highly desirable product fractions even with dilute gaseous reactants.

Sapienza, Richard S. (Shoreham, NY); Sansone, Michael J. (Summit, NJ); Slegeir, William A. R. (Hampton Bays, NY)

1984-01-01

267

Deep desulfurization of hydrocarbon fuels  

Science.gov (United States)

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.

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

2012-04-17

268

Biomaterial Guides for Lymphatic Endothelial Cell Alignment and Migration  

Science.gov (United States)

Axillary dissection during breast cancer surgery produces extensive lymphatic vessel damage that often leads to life-long secondary lymphedema of the arm. We have developed a biodegradable material conduit for lymphatic vessel reconstruction where fibers electrospun along the conduit lumen promote endothelial cell alignment and migration, in vitro. The diameter and density of the electrospun fibers were optimized for cell migration and direction on 2-dimensional substrates by seeding human lymphatic endothelial cells (LECs) onto aligned fibers of varying diameters and densities, randomly oriented fibers, and film substrates with no fibers. We found that LECs became aligned in the fiber direction, with cells seeded on the randomly oriented fibers becoming oriented in random directions, whereas cells seeded on the highly aligned fibers became highly aligned. Cell migration was dependent upon fiber alignment and density, with optimal migration found on 1300 nm diameter aligned fibers of low density. Blood endothelial cells seeded on the fibers exhibited similar behavior as the LECs. Fiber alignment was preserved upon rolling the 2-dimensional substrate into the tubular geometry of a lymphatic vessel. The data suggest that aligned electrospun fibers may promote endothelial migration across the conduit in a manner that is independent of lymphatic growth factors. PMID:20974299

Bouta, Echoe M.; McCarthy, Connor W.; Keim, Alexander; Wang, Han Bing; Gilbert, Ryan J.; Goldman, Jeremy

2010-01-01

269

Quantitative evaluation of the geologic evolution and hydrocarbon potential of the Gulf of Gabes, Tunisia  

Energy Technology Data Exchange (ETDEWEB)

A quantitative basin modelling study is carried out, using YUKLERPC{sup R} software and all the available data in ETAP, Tunis, to provide the necessary data for the ranking of prospects the permits in and around the Gulf of Gabes, Tunisia, and to aid in the selection of target(s). Fifty-eight wells with pressure, porosity, temperature and maturity data are modeled to construct the conceptual model in terms of paleoenvironments, lithofacies, type of geologic events and their durations, and heat flow. The oil/condensate and gas shows are used as checks on the generation of hydrocarbons. The conceptual model is then used in the modelling of fifty-one pseudo-wells, together with the real wells, to quantify the geologic evolution and hydrocarbon potential of the gulf within a continuous three-dimensional geological framework. The computed subsidence and the optimized heat flow histories show that the subsidence of the subbasins within and around the Gulf of Gabes from the Callovian to the Berriasian, from the heat flow values first increased and then decreased during these times. Major uplift and erosion took place during the Tortonian and the mid-late Pliocene which altered the subsurface topography and affected the timing of trap formation and trap size. The last heat flow increase and the late Tertiary sedimentation were the controlling factors for the generation and migration of hydrocarbons. The effective hydrocarbon generation and migration took place only during the last 4 my within and around the Gulf of Gabes. The occurrence of economic hydrocarbon accumulations, however, are directly related to the pressure histories during the last 5 my. In the areas where high abnormal pressure took place, the carbonate reservoirs are fractured and have good reservoir properties. In the areas where major uplift and erosion took place during the 3 to 1 mybp, subnormal pressures occurred leading to seal failures and, thus, resulted in non-economical accumulations.

Yukler, M.A.; Moumen, A.; Daadouch, I. [and others

1995-08-01

270

Hydrocarbon source potential determined by Rock Eval/TOC data from the Canadian Arctic Islands  

Energy Technology Data Exchange (ETDEWEB)

Rock Eval analysis has been used to define new hydrocarbon plays in areas of complex salt deformation on Axel Heiberg Island in the Arctic. A study was conducted in which 6320 Rock Eval and 19,700 total organic carbon (TOC) analyses from 109 oil and gas wells and 1650 outcrops were used to characterize the hydrocarbon source potential of the 18 major tectonostratigraphic successions from the Phanerozoic sedimentary basins of the Arctic Islands. The objective was to determine the quantity, quality, and thermal maturity of indigenous sedimentary organic matter and migrated hydrocarbons. This paper listed the stratigraphic successions that contain many samples with TOC greater than 1.0 per cent. Oil-prone, Type 1 and 2 kerogen is the dominant organic matter in the Silurian basinal succession, Carboniferous Emma Fiord Formation, Triassic Schei Point Group, and Cretaceous Kanguk Formation. It occurs in thin, discontinuous intervals within algal-rich beds in the Cambro-Ordovician carbonate succession; flysch shed from the Devonian Boothia uplift; shallow-water carbonates of the Devonian carbonate succession; coal in the Devonian clastic wedge; and as rare, possibly coaly intervals in the Triassic Bjorne, Barrow and Grovesnor Island formations. The thickness and extent of these oil-prone source beds are poorly constrained. These source beds are likely minor contributors to the total petroleum resource in the Arctic Islands. The S1 parameter from Rock Eval indicates the amount of migrated hydrocarbon, or those pyrolyzed at low temperatures. Histograms of S1 for each of the main hydrocarbon source rock intervals help determine if an active petroleum system was present. Histograms of the total gas derived from cuttings also reveal which source intervals may have generated gas. The Schei Point Group has very high S1 values but very low cuttings gas. The younger and less thermally mature McConnell Island-Deer Bay succession has much higher cuttings gas.

Dewing, K.; Obermajer, M.; Harrison, C. [Natural Resources Canada, Calgary, AB (Canada). Geological Survey of Canada

2007-07-01

271

HANDICRAFTS, INVASIONS AND MIGRATIONS  

Directory of Open Access Journals (Sweden)

Full Text Available This research is focused on the migratory movements that have characterized Simojovel de Allende, Chiapas. Both indigenous Tsotsil communities as well as mestizos from different municipalities live in Simojovel, which is a town that has had multiple migratory movements due to different reasons. For example, economical struggle that has led to poverty, the lack of opportunities; the political situation, religious and ethnic persecutions, insecurity and the communitarian division between zapatistas and non-zapatistas. There are also cultural factors that have caused migration in Simojovel such as tradition, generational gaps, young people’s interests for new types of work and ways of living. Simojovel has been characterized by its coffee, tobacco and amber, but also by its migratory activity.

Perla Shiomara del Carpio Ovando

2014-01-01

272

Nightly Test system migration  

CERN Document Server

The summer student program allows students to participate to the Cern adventure. They can follow several interesting lectures about particle science and participate to the experiment work. As a summer student, I had worked for LHCb experiment. LHCb uses a lot of software to analyze its data. All this software is organized in packages and projects. They are built and tested during the night using an automated system and the results are displayed on a web interface. Actually, LHCb is changing this system. It is looking for a replacement candidate. So I was charged to unify some internal interfaces to permit a swift migration. In this document, I will describe shortly the system used by LHCb, then I will explain what I have done in detail.

Win-Lime, Kevin

2013-01-01

273

Brine migration: a summary report  

International Nuclear Information System (INIS)

As defined in this report, brine migration is the movement toward a heat source of the water trapped in rock salt. This phenomenon is of interest because the disposal of heat-producing radioactive wastes can trigger brine migration. Contact between the brine and the waste packages could lead to such undesirable interactions as corrosion of the canister or even migration of the radionuclides. This report summarizes a Sandia National Laboratories program to characterize brine migration. Based on this program and on the work of others, we conclude that brine migration is not a significant problem. The quantities of water (less than 20 L/waste canister in 1000 yr) are too small for concern

274

Adherens junctions during cell migration.  

Science.gov (United States)

Migration is a key cellular process, involved during morphogenetic movements as well as in the adult where it participates in immune cell trafficking, wound healing or tumour invasion. As they migrate, cells interact with a microenvironment composed of extracellular matrix and neighbouring cells. Cell-cell adhesions ensure tissue integrity while they allow migration of single or grouped cells within this tissue. Cadherin and nectin-based adherens junctions are key players in intercellular interactions. They are used as adhesive complexes whose mechanical properties improve cell coordination during collective migration and promote cell motility on cadherin substrates. In addition, adherens junctions transduce signals that actively participate in the control of directed cell migration, by providing polarity cues and also participating in contact inhibition of motility. PMID:22674074

Etienne-Manneville, Sandrine

2012-01-01

275

DNAPL migration in a coastal plain aquifer  

International Nuclear Information System (INIS)

Soil and ground water at the Dover Gas Light Superfund Site, a former manufactured gas plant (1859 to 1948), are contaminated with polynuclear aromatic hydrocarbons and volatile organic compounds. Contaminants of concern include light aromatics, such as benzene, toluene, ethylbenzene, and xylenes (BTEX), and heavy aromatics, including naphthalene, acenaphthylene, phenanthrene, and benzo(a)pyrene. Although ground-water contaminant levels are elevated near the site, only naphthalene and acenaphthylene are present within an order of magnitude of their solubility limits, indicating the possibility of dense non-aqueous phase liquids (DNAPL) in the subsurface. The unconfined Columbia Aquifer, which is characterized by interfingering and discontinuous sand, silt, and clay Coastal Plain deposits, overlies a clay aquitard at a depth of 60 feet. The ground water beneath the intermediate clay horizon exhibited little or no contamination, even immediately downgradient from the site. The relationship between the more permeable granular sand horizons and the less permeable interfingering clay zones controls the migration of both the aqueous-phase contamination and the DNAPL. A detailed horizontal and vertical characterization of the subsurface stratigraphy was critical to the accurate interpretation of the extent and magnitude of contamination and the identification and delineation of DNAPL zones

276

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

277

Green Methodologies to Test Hydrocarbon Reservoirs  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 ...

Francesca Verga; Vera Rocca

2010-01-01

278

DIAMOND SECONDARY EMITTER  

Energy Technology Data Exchange (ETDEWEB)

We present the design and experimental progress on the diamond secondary emitter as an electron source for high average power injectors. The design criteria for average currents up to 1 A and charge up to 20 nC are established. Secondary Electron Yield (SEY) exceeding 200 in transmission mode and 50 in emission mode have been measured. Preliminary results on the design and fabrication of the self contained capsule with primary electron source and secondary electron emitter will also be presented.

BEN-ZVI, I.; RAO, T.; BURRILL, A.; CHANG, X.; GRIMES, J.; RANK, J.; SEGALOV, Z.; SMEDLEY, J.

2005-10-09

279

Vaporization and gasification of hydrocarbon feedstocks  

Energy Technology Data Exchange (ETDEWEB)

Heavy hydrocarbon feedstocks, e.g. gas oils, are vaporized and subsequently gasified at high temperatures without pyrolytic degradation by first admixing the hydrocarbon with a hot gaseous reactant, e.g. product gas or steam, to bring the temperature of the mixture above that of the dew point of the hydrocarbon and thereafter raising the temperature of the mixture to above that at which pyrolysis of the hydrocarbon begins to be significant by admixture with further quantities of the reactant which are superheated thereby to bring the temperature of the resultant mixture to that required for effecting a catalytic gasification reaction.

Davies, H.S.; Garstang, J.H.; Timmins, C.

1983-08-23

280

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)

 
 
 
 
281

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.)

282

Hydrothermal dolomitization in the Lower Silurian La Vieille Formation in northern New Brunswick : geological context and significance for hydrocarbon exploration  

Energy Technology Data Exchange (ETDEWEB)

Since hydrothermal dolomites are known to host hydrocarbon reservoirs, they constitute a significant play for exploration companies seeking large hydrocarbon reservoirs. The process of hydrothermal alteration and dolomitization has been documented in the Gaspe Peninsula and in northern New Brunswick. This study described the hydrocarbon potential of the Late Ordovician to Middle Devonian Gaspe Belt in northern New Brunswick with particular reference to evidence of hydrothermal alteration of the limestone facies. Six stratigraphic sections of the Lower Silurian La Vieille Formation were examined during the summer of 2004 for facies architecture. The observations that substantiate hydrothermal alteration of the La Vieille Formation include early fractures; brecciation associated with early fractures; dissolution features associated with early fractures; large scale collapse of sections; fracture-filling cements; pervasive dolomitization; and, synsedimentary tectonic instability. Early hydrothermal alternation also resulted in leaching and the development of porous intervals into which hydrocarbons migrated. Forty-five samples were collected for petrographic and carbon and oxygen stable isotope ratios analysis. It was concluded that thermal maturation in areas of northern New Brunswick is conducive for preservation of hydrocarbons and that Upper Ordovician hydrocarbon source rocks may be present. 56 refs., 2 tabs., 10 figs.

Lavoie, D. [Natural Resources Canada, Quebec, PQ (Canada). Geological Survey of Canada, Quebec Division; Chi, G. [Regina Univ., SK (Canada). Dept. of Geology

2006-12-15

283

Estimate of global atmospheric organic aerosol from oxidation of biogenic hydrocarbons  

Science.gov (United States)

The results from a series of outdoor chamber experiments establishing the atmospheric aerosol-forming potential of fourteen terpenoid hydrocarbons have been used to estimate the annual amount of secondary organic aerosol formed globally from compounds emitted by vegetation. Hydroxyl radical, ozone, and nitrate radical oxidation each contribute to aerosol formation in full-photooxidation experiments; because oxidation by nitrate radical under ambient, remote conditions is likely to be negligible, parameters describing aerosol formation from hydroxyl radical and ozone reaction only are developed. Chamber results, temporally and spatially resolved, compound-specific estimates of biogenic hydrocarbon emissions, and hydroxyl radical and ozone fields are combined to lead to an estimate for atmospheric secondary organic aerosol formed annually from biogenic precursors of 18.5 Tg, a number smaller than the previously published estimate of 30-270 Tg [Andreae and Crutzen, 1997].

Griffin, Robert J.; Cocker, David R., III; Seinfeld, John H.; Dabdub, Donald

284

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)

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

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

2014-05-01

285

Constraints on the origins of hydrocarbon gas from compositions of gases at their site of origin  

Science.gov (United States)

It is widely accepted that natural gas is formed from thermal decomposition of both oil in reservoirs and, to a lesser extent, the organic matter in shales from which the oil was derived. But laboratory pyrolysis experiments on shales do not reproduce the methane-rich composition typical of most gas reservoirs, leading to suggestions that other mechanisms, such as transition-metal catalysis, may be important. The discrepancy might, however, instead arise because gas (and oil) deposits have migrated from their source rocks, so that the reservoir composition might not be representative of the composition in the source rocks where the hydrocarbons were generated. To address this question, we have analysed gas samples coproduced with oils directly from a source rock (the Bakken shales, North Dakota, USA) where the local geology has prevented significant hydrocarbon migration. The methane contents of these Bakken-shale gases are much lower than that of conventional gas reservoirs, but are consistent with that from pyrolysis experiments on these shales. Thus, because these Bakken gases form with (rather than from) oils, we argue that compositional differences between gases from source rocks and conventional gas deposits result from fractionation processes occurring after hydrocarbon expulsion from the source rock. PMID:11536709

Price, L C; Schoell, M

1995-11-23

286

Case study of a novel geocomposite barrier system for hydrocarbon containment on Brevoort Island  

Energy Technology Data Exchange (ETDEWEB)

North Warning System Office has undertaken a program focused on the cleanup of Canadian District Early Warning Line and Pole Vault sites located on the Canadian sub-Arctic and Arctic coastline. The implementation plan emphasizes cost-effective methods of preventing the movement of chemical contaminants into the ecosystem. This paper describes remediation steps that were taken to restrict the migration of a hydrocarbon plume before the excavation of contaminated ground at a Pole Vault site on Brevoort Island. This is the first published field application of a fluorinated geomembrane. A composite liner consisting of fluorine surface-treated polyethylene geomembrane and a geosynthetic clay liner was chosen as a barrier against hydrocarbon migration until full remediation measures could be applied. Design details, selection criteria and various challenges in the installation procedure were presented. Due to the remoteness of the location and the extremes of temperature, a site monitoring program was also initiated. Details of the programs were also presented, along with details of a parallel program of laboratory testing, initiated to investigate the long-term effects of contact with jet fuel on specimens of the barrier components as well as freeze-thaw and general lower temperatures. Results indicated that the barrier system was performing as planned. Laboratory tests indicated that the geosynthetic materials selected for the Brevoort site were expected to maintain low rates of hydrocarbon diffusion and advection beyond the original design life of the barrier system. 14 refs., 10 figs.

Bathurst, R.J.; Zeeb, B.; Reimer, K. [Royal Military Coll. of Canada, Kingston, ON (Canada); Rowe, R.K. [Queen' s Univ., Kingston, ON (Canada)

2005-07-01

287

Nitrogen Analogues of Thiele's Hydrocarbon.  

Science.gov (United States)

A series of bis[N,N-di-(4-methoxylphenyl)amino]arene dications 1(2+) -3(2+) have been synthesized and characterized. Their electronic structures were investigated by various experiments assisted by theoretical calculations. It was found that they are singlets in the ground state and that their diradical character is dependent on the bridging moiety. 3(2+) has a smaller singlet-triplet energy gap and its excited triplet state is thermally readily accessible. The work provides a nitrogen analogue of Thiele's hydrocarbon with considerable diradical character. PMID:25504531

Su, Yuanting; Wang, Xingyong; Li, Yuantao; Song, You; Sui, Yunxia; Wang, Xinping

2015-01-26

288

Effective viscosity of confined hydrocarbons  

DEFF Research Database (Denmark)

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

Sivebæk, Ion Marius; Samoilov, V.N.

2012-01-01

289

Migration of Pu and Am  

International Nuclear Information System (INIS)

Results are reported from studies on the mechanisms involved in the migration of long-lived isotopes of Pu and Am released from radioactive waste depositories through fissures or pores in rocks and soils. The surface absorption coefficients of Pu and Am were measured in a static system by equilibrating solid samples of stone (solid cores of Los Alamos tuff and Idaho basalt) of known surface area with solutions of Pu or Am in the appropriate chemical milieu. It was shown that the static coefficients and physical constants of the system were sufficient to predict the distance migrated. A computer model of Pu and Am migration was developed

290

"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.

291

Psychosocial Aspects of Migration  

Directory of Open Access Journals (Sweden)

Full Text Available The incident of migration that occurs as a result of the mobility of individuals between various regions and is considered a social change process brings along various factors. Among these factors, the most important one is the culture of the new society where the immigrant begins to live and the process of adaptation with this culture. Individuals from different cultures are required to live together, cope with differences and overcome the difficulties. The process of adaptation to the new lifestyle might cause the individual to have some feelings such as loneliness, socially isolation, being alienated, being regretful and self-depreciation, and consequently experience a greater stress. Being unable to cope with stress efficiently creates risks in individuals in terms of health problems such as anxiety and depression. Healthcare professionals are required to evaluate life styles, difficulties and coping levels of immigrants in order to protect and develop their mental health. [Psikiyatride Guncel Yaklasimlar - Current Approaches in Psychiatry 2014; 6(1.000: 56-66

Ayla Tuzcu

2014-02-01

292

Melatonin and nocturnal migration.  

Science.gov (United States)

Many species of diurnal birds migrate nocturnally. Here, a series of studies of the blackcap (Sylvia atricapilla) on the relationship between nocturnal restlessness and melatonin, a hormone that in birds modulates day-night rhythms, are reviewed. Migratory populations from Sweden and Kenya were compared with resident populations from Cape Verde. In blackcaps of migratory populations, night levels of melatonin were lower during the migratory period, when birds showed nocturnal activity, than before and after this period, when birds did not show nocturnal activity. On the contrary, the occurrence of periodic or irregular phases of nocturnal activity in some nonmigratory birds from Cape Verde was not accompanied by a reduction in melatonin levels. In a second series of experiments, it was studied whether melatonin levels change when nocturnally active blackcaps are experimentally transferred from a migratory to a nonmigratory state. A long migratory flight and a refueling stopover were simulated by depriving birds of food for 2 days, subsequently readministering food. The experiments were done in autumn with birds collected in Sweden, and repeated in spring with birds collected in Kenya. In autumn, there was a suppression of nocturnal activity and an increase in melatonin in the night following food reintroduction. In spring, the effects were qualitatively similar, but their extent depended on the amount of body fat reserves. Taken together, the studies demonstrate the existence of a functional relationship between melatonin and nocturnal restlessness and of seasonal differences in the response of the migratory program to food availability. PMID:16055859

Fusani, Leonida; Gwinner, Eberhard

2005-06-01

293

Radionuclide migration in soils  

International Nuclear Information System (INIS)

Unplanned releases from a nuclear installation - e.g., leakage from a storage tank or other incident - can result in the escape of contaminants such as U, Pu, Cs, Sr, T etc. Nuclide transport through the ground is governed by characteristics of the subsurface hydrology and the specific nuclides under consideration. Unsaturated soil layers result in a transport rate so low as to negligible. Radionuclides reaching the ground water are assumed to endanger human life because of potential uncontrolled ingestion. The most dangerous nuclides are long-lived and not absorbed, or very poorly absorbed, in the soil. During migration of nuclides through saturated soil layers, the concentration can be reduced by dilution. Preliminary results indicate that tritium is spread with ground water velocity. Its concentration can be reduced only by diffusion, dispersion and radioactive decay. Alpha-emitters are strongly retained velocities of alpha-emitters are approximately one thousandth (10-3) that of T. Transport velocities of Cs and Sr are approximately one hundreth (10-2) and one tenth (10-1) that of T respectively. (orig./HP)

294

27 CFR 21.125 - Rubber hydrocarbon solvent.  

Science.gov (United States)

...2010-04-01 2010-04-01 false Rubber hydrocarbon solvent. 21.125...Specifications for Denaturants § 21.125 Rubber hydrocarbon solvent. (a) Rubber hydrocarbon solvent is a petroleum derivative. (b) Distillation...

2010-04-01

295

40 CFR 86.1221-90 - Hydrocarbon analyzer calibration.  

Science.gov (United States)

...2010-07-01 false Hydrocarbon analyzer calibration. 86.1221-90 Section 86.1221-90...86.1221-90 Hydrocarbon analyzer calibration. The FID hydrocarbon analyzer shall...receive the following initial and periodic calibrations. (a) Initial and periodic...

2010-07-01

296

40 CFR 92.119 - Hydrocarbon analyzer calibration.  

Science.gov (United States)

...2010-07-01 false Hydrocarbon analyzer calibration. 92.119 Section 92.119 Protection... § 92.119 Hydrocarbon analyzer calibration. The HFID hydrocarbon analyzer shall...receive the following initial and periodic calibration: (a) Initial and periodic...

2010-07-01

297

40 CFR 86.1321-94 - Hydrocarbon analyzer calibration.  

Science.gov (United States)

...2010-07-01 false Hydrocarbon analyzer calibration. 86.1321-94 Section 86.1321-94...86.1321-94 Hydrocarbon analyzer calibration. The FID hydrocarbon analyzer shall...receive the following initial and periodic calibration. The HFID used with...

2010-07-01

298

40 CFR 89.319 - Hydrocarbon analyzer calibration.  

Science.gov (United States)

... false Hydrocarbon analyzer calibration. 89.319 Section 89.319...319 Hydrocarbon analyzer calibration. (a) The FID hydrocarbon...receive the initial and periodic calibration as described in this...

2010-07-01

299

Secondary acute pneumonias  

International Nuclear Information System (INIS)

Pathological changes, promoting the development of secondary pneumonias, are investigated. To this group belong: blood circulation disturbance in small circle, bronchial passability disturbance, aspiration of liquids, gases and vapors, infections and purulent processes, intoxications, injuries, operative interference. Roetgenologic symptomatics of each secondary acute pneumonia form is presented in detail

300

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)

 
 
 
 
301

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

Directory of Open Access Journals (Sweden)

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

Hélène Thiollet

2010-12-01

302

Facets of Secondary Polytopes  

CERN Document Server

The secondary polytope of a point configuration $\\cA$ is a polytope whose face poset is isomorphic to the poset of all regular subdivisions of $\\cA$. While the vertices of the secondary polytope -- corresponding to the triangulations of $\\cA$ -- are very well studied, there is not much known about the facets of the secondary polytope. The splits of a polytope, subdivisions with exactly two maximal faces, are the most simple example of such facets and the first that were systematically investigated. The present paper can be seen as a continuation of this and as a starting point of an examination of the subdivisions corresponding to the facets of the secondary polytope in general. As a special case, the notion of $k$-split will be introduced as a possibility to classify polytopes in accordance to the complexity of the facets of their secondary polytopes. An application to matroid subdivisions of hypersimplices and tropical geometry is given.

Herrmann, Sven

2009-01-01

303

Simulation of the migration of mineral oil from recycled paperboard into dry foods by Tenax®?  

Science.gov (United States)

Conventional migration testing for long-term storage at ambient temperature with Tenax® was applied to a recycled paperboard as well as to the same paperboard with a polyethylene or polypropylene film in between. Test conditions were from the European Union plastic Regulation 10/2011, that is, 10 days at 60°C, but previous standard conditions of 10 days at 40°C were also applied. The results were compared with the migration into real packs made of the same packaging material containing six test foods and stored over 9 months. For the direct contact, simulation at 60°C overestimated the maximum migration of the saturated hydrocarbons in the real packs by 73%. Simulation reflected hardly any effect by the plastic films and resulted in an overestimation of the maximum migration into the real packs by a factor of 5.1 and 27 for the polyethylene and the polypropylene film, respectively. Analogous simulation was performed with polenta (corn semolina) instead of Tenax®. Three main causes for this deviation were identified: (i) at 60°C, migration reached beyond n-C??, whereas it ends at about n-C?? in reality. (ii) Tenax® is a far stronger adsorbent than foods, resulting in almost complete extraction. (iii) The significant barrier effect of polypropylene films at ambient temperature is lost at increased temperature. The suitability of such simulation for the prediction of long-term migration is questioned. PMID:23710606

Zurfluh, Michael; Biedermann, Maurus; Grob, Koni

2013-01-01

304

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)

305

Considerations and applications of the illite/smectite geothermometer in hydrocarbon-bearing rocks of Miocene to Mississippian age  

Science.gov (United States)

Empirical relationships between clay mineral transformations and temperature provide a basis for the use of clay minerals as geothermometers. Clay-mineral geothermometry has been applied mainly to diagenetic, hydrothermal, and contact- and burial-metamorphic settings to better understand the thermal histories of migrating fluids, hydrocarbon source beds, and ore and mineral formation. Quantitatively, the most important diagenetic clay mineral reaction in sedimentary rocks is the progressive transformation of smectite to illite via mixed-layer illite/smectite (I/S). Changes in the ordering of I/S are particularly useful in the exploration for hydrocarbons because of the common coincidence between the temperatures for the conversion from random-to-ordered I/S and those for the onset of peak, or main phase, oil generation. Using three common applications, the I/S geothermometer is compared to other mineral geothermometers, organic maturation indices, and grades of indigenous hydrocarbons. -from Author

Pollastro, R.M.

1993-01-01

306

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

307

Data Migration Across The Clouds  

Directory of Open Access Journals (Sweden)

Full Text Available Having an effective and efficient strategy for optimizing long distance data migration is essential for every data center. With the ever increasing demands for the IT needs of businesses it is also important for data centers to deliver data migration cost effectively especially when faced with the demands from remote office back up, outsourcing, data center movers and cloud computing. Data management and migration are important research challenges of novel Cloud environments. While moving data among different geographical domains, it is important to lower the transmission cost for performance purposes. Efficient scheduling methods allow us to manage data transmissions with lower number of steps and shorter transmission time. In previous research efforts, several methods have been proposed in literature in order to manage data and minimize transmission cost for the case of Single Cluster environments. This paper Explores the issues and method of Data Migration across the Clouds

Prashant Pant,

2013-05-01

308

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

309

Palaearctic-African Bird Migration  

DEFF Research Database (Denmark)

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.

Iwajomo, Soladoye Babatola

2013-01-01

310

Hydrocarbon Collision Database: Revisions, Upgrades and Extensions  

International Nuclear Information System (INIS)

Kinetic analysis of the behaviour of hydrocarbons in fusion plasmas requires knowledge of cross-sections for their most relevant collision processes. Upgrades and extensions of the HYDKIN (HYDride KINetics) on-line cross-section database and analysis toolbox for collisions of hydrocarbons with electrons and protons in relevant fusion plasma conditions are presented. (author)

311

Does Higher Education Enhance Migration?  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper examines the causal impact of education on within-country migration. A major higher education reform took place in Finland in the 1990s. It gradually transformed former vocational colleges into polytechnics and expanded higher education to all regions. The reform created exogenous variation in the regional supply of higher education. Using the reform as an instrument, our estimation results show that polytechnic graduates have a 7.5 (13.7) percentage points higher migration probabi...

Haapanen, Mika; Bo?ckerman, Petri

2013-01-01

312

Migration of radionuclides in soil  

International Nuclear Information System (INIS)

Due to the growing amounts of low-level radioactive waste being produced from the nuclear industry and research establishments, there is considerable interest in the study of migration of radionuclides from the shallow-land burial sites. A brief description is presented about some aspect of effectiveness of soil in retarding the migration of radionuclides with special emphasis given to those environmentally critical fission and activation products, elements. (author)

313

Une histoire longue des migrations  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Pour l’Antiquité, l’historiographie s’est longtemps représenté les migrations de façon très globale, comme des migrations de peuplement, en les reliant souvent aux conflits militaires, faute de pouvoir en cerner finement les contours. En revanche, à partir du Moyen-Âge, l’historien est capable d’individualiser les flux migratoires avec une relative précision – qui bien sûr va croissante à mesure que l’on se rapproche de la période actuelle (...).

Rosental, Paul-andre

2010-01-01

314

The international-migration network  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 ...

Fagiolo, Giorgio; Mastrorillo, Marina

2012-01-01

315

Gender and Migration in Jordan  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract This study explores Jordan’s policies in regards to international migration in general and to migrant women in particular. It has four sections: women’s participation in the workforce in Jordan; the national and international framework for migration to Jordan; the question of transferability of Jordanian citizenship from a Jordanian woman, married to a non–citizen, to her children; and women immigrating to Jordan. Résumé Cette étude explore les politiques jordanien...

Olwan, Mohamed Y.

2010-01-01

316

Migration to the public cloud  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Along with the development of cloud computing technology, website owners begin to consider migrating their website from private in-house server to public cloud servers. In this paper, we use a principal-agent model to analyze the underlying economic trade-offs of such migration and then extend it into a dynamic environment. Our results indicate that the trade-off between market information precision and rent extraction affects the decision choice between private server and public cloud in the...

Wang, Tong

2013-01-01

317

Isolation and FIMS analysis of saturated hydrocarbons from tar sand bitumens  

Energy Technology Data Exchange (ETDEWEB)

Saturated hydrocarbons in two Utah tar sand bitumens were determined via compound-type isolation and mass spectral analyses. Four analytical methods for isolating saturated hydrocarbons were evaluated: 1) dewaxing, 2) modified deasphaltening, 3) adsorption and complexation chromatography, 4) desorptive Soxhlet extraction followed by complexation chromatography. The latter method was preferred for concentrating the greatest amount of saturated hydrocarbons without overlap from aromatic or heteroatom-containing species. Field ionization mass spectrometry (FIMS) adequately profiled these hydrocarbons by molar mass (m/z) and by Z-series type. The sample of Northwest Asphalt Ridge bitumen was comprised of a wax of mostly acyclic and monocycloalkanes; whereas, the saturates from the sample of Asphalt Ridge bitumen were mostly tetracyclo- and pentacycloalkanes. Based upon a comparison of the saturate distributions in the samples of bitumen, the sample from the Northwest Asphalt Ridge deposit was found to have undergone less biodegradation. This wax-like sample of bitumen may have migrated to the deposit at a later time than the major bitumen generation and/or resulted from physicochemical segregation of waxy organic matter in the reservoir. 22 refs., 5 figs., 2 tabs.

Holmes, S.A.; Raska, K.A.

1986-11-01

318

Geodynamics of ophiolites and formation of hydrocarbon fields on the shelf of eastern Sakhalin  

Science.gov (United States)

A model is proposed showing the formation of hydrocarbon fields on the shelf of eastern Sakhalin as being caused by sustained (from the Late Cretaceous to the present) extension in the adjacent deepwater Deryugin Basin with exposure of the upper mantle rocks at the bottom of the sedimentary basin. The thrust faults and detachments formed through this process facilitated the penetration of seawater into ultramafic rocks, thus providing large-scale serpentinization accompanied by generation of hydrocarbons. Extension in the Deryugin Basin was compensated by horizontal shortening at its margins, and as a result, by the formation of ophiolitic allochthons as constituents of the accretionary prism of eastern Sakhalin. Hydrocarbons were injected and pumped in the root zones of the allochthons, giving rise to their westward migration and the formation of petroleum pools in fault-line and underthrust traps on the shelf of Sakhalin Island. The Deryugin Basin is a petroleum-collecting area for oil and gas fields localized in the upper part of its western margin. More broadly, the work considers interrelations between hydrocarbon generation and the geodynamics of tectonic couples of ophiolitic allochthons and adjacent deepwater basins of marginal seas, in particular, in the western Pacific.

Raznitsin, Yu. N.

2012-01-01

319

New hydrologic model of fluid migration in deep porous media  

Science.gov (United States)

The authors present a new hydrological model of mantle processes that effect on formation of oil-and-gas bearing basins, fault tectonics and thermal convection. Any fluid migration is initially induced by lateral stresses in the crust and lithosphere which result from global geodynamic processes related to the mantle convection. The global processes are further transformed into regional movements in weakness zones. Model of porous media in deep fractured zones and idea of self-oscillation processes in mantle layers and fractured zones of the crust at different depths was used as the basis for developed concept. The content of these notions resides in the fact that there are conditions of dynamic balance in mantle layers originating as a result of combination and alternate actions of compaction and dilatance mechanisms. These mechanisms can be manifested in different combinations and under different conditions as well as can be complemented by other processes influencing on regime of fluid migration. They can act under condition of passive margin, ocean rift and ocean subduction zones as well as in consolidated platform and sheet. Self-oscillation regime, sub vertical direction of fluid flows, anomalously high layer pressure, and high level of anomalies of various geophysical fields are common for them. A certain class of fluid dynamic models describing consolidation of sedimentary basins, free oscillation processes slow and quick (at the final stage) fluid dynamic processes of the evolution of a sedimentary basin in subduction zones is considered for the first time. The last model of quick fluid dynamic processes reflects the process of formation of hydrocarbon deposits in the zones of collision of lithosphere plates. The results of numerical simulation and diagrams reflecting consecutive stages of the gas-fluid dynamic front propagation are assessed of the Pri-Caspian depression as the example. Calculations with this model will simultaneously be carried out for the sedimentary basins of Timan-Pechora region, Barents Sea, Volga-Ural area, etc. Hydrologic model of deep porous media and the idea of self-oscillation processes in fractured layers of the crust at different depths were used as the basis for developed concept. The content of these notions resides in the fact that there are conditions of dynamic balance in fractured layers originating as a result of combination and alternate actions of compaction and dilatance mechanisms. These mechanisms can be manifested in different combinations and under different conditions as well as can be complemented by other processes influencing on regime of fluid migration. They can act under condition of passive margin, rift and subduction zones as well as in consolidated platform and sheet. Self-oscillation regime, sub vertical direction of fluid flows, anomalously high layer pressure, and high level of anomalies of various geophysical fields are common for them. Specific manifestations of these mechanisms can vary in dependence on geological settings and geodynamic situations. In particular, periods of self-oscillations and depths of fractured layers can be various. Orientation of layers can be not only horizontal, but vertical as well, that is, self-oscillations can occur not only in deep porous media, but in faults and impaired fractured zones as well. Predominating vertical fluid migration can be accompanied by horizontal migration along crust waveguide. A set of fluid dynamic models is considered. Mathematical modeling of geodynamic and fluid dynamic processes in these zones seems very promising. Combined consideration of geodynamic and fluid dynamic aspects in a model of lithosphere plates collision enables to understand the influence of P-T conditions and shear deformations on the mechanism of hydrocarbon generation and to look after their migration and to explain these processes, but also to predict some features essential for the search and exploration of hydrocarbon fields in these regions and their classification. In terms of compaction models, multiphase filtration in a

Dmitrievsky, A.; Balanyuk, I.

2009-04-01

320

European Integration and Labour Migration  

Directory of Open Access Journals (Sweden)

Full Text Available The present paper studies how European integration might affect the migration of workers in the enlarged EU. Unlike the reduced-form migration models, we base our empirical analysis on the theory of economic geography à la Krugman (1991, which provides an alternative modelling of migration pull and push factors. Parameters of the theoretical model are estimated econometrically using historical migration data. Our empirical findings suggest that European integration would trigger selective migration between the countries in the enlarged EU. In the Baltics, Lithuania would gain about 7.25% of the total work force. In the Visegrád Four, the share of the mobile labour force would increase the most in Hungary, 8.35%, compared to the pre-integration state. Our predictions for the East-West migration are moderate and lower than those of reduced-form models: between 5.44% (from the Baltics and 3.61% (from the Visegrád Four would emigrate to the EU North. Because migrants not only follow market potential, but also shape the region’s market potential, the long-run agglomeration forces are sufficiently weak to make a swift emergence of a core-periphery pattern in the enlarged EU very unlikely.

Julda Kielyte

2010-11-01

 
 
 
 
321

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

322

Private sector perspectives on hydrocarbon contamination  

International Nuclear Information System (INIS)

In order to effectively resolve a problem, one should attempt to gain a comprehensive understanding of all facets of the problem. With regard to hydrocarbon contamination, it is essential for regulators, consultants, attorneys, bankers, business owners, and others involved with this issue to develop a comprehensive understanding of the major perspectives associated with hydrocarbon contamination in order to address and effectively resolve the specific hydrocarbon contamination issues these groups are, or will be, facing. The purpose of this paper is to identify the hydrocarbon contamination issues from private and public sector perspectives. In doing so, the author hopes to present another important perspective that will provide those involved with hydrocarbon contamination a more complete picture of the scope of the problem

323

Distribution of hydrocarbon concentrations as basis for predicting most promising gas deposits  

Energy Technology Data Exchange (ETDEWEB)

Study of petroleum and gas deposit distribution mechanism within the Western Siberian platform, the Dneprovsko-Donestkaya and TimanoPeechorskii basins is presented. Using these regions with varying geologic structure and development history, basic causes of zonal distribution of hydrocarbon deposits (with varying phases and spatial separation of primarily gas-and petroleum-bearing zones) are discussed. In some cases, the leading role of primary genetic factors (West Siberian platform) is noted; in others, the important role of migration and hydrocarbon concentration (TimanoPechorskii). Gas-production potential of the examined regions has been established, and goals of geologic/exploratory operations directed at open gas-condensate deposits have been outlined.

Zhabryev, I.P.; Bereto, Y.A.; Leongardt, N.I.; Pashkevich, Y.I.; Skorobogatov, V.A.; Yermakov, V.I.

1981-01-01

324

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)

325

The financial losses from the migration of nurses from Malawi  

Directory of Open Access Journals (Sweden)

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.

Muula Adamson S

2006-11-01

326

The Relationship between Ethnic Diversity and Classroom Disruption in the Context of Migration Policies  

Science.gov (United States)

This paper studies the relationship between ethnic school composition and classroom disruption in secondary education in the context of migration policies. We measured classroom disruption using students' reports from 3533 schools in 20 countries provided by cross-national PISA (Programme for International Student Assessment) 2009 data. We…

Veerman, Gert-Jan M.

2015-01-01

327

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 ten...

Hélène Thiollet

2010-01-01

328

Hydrocarbon Seeps Formations: a Study Using 3-D Seismic Attributes in Combination with Satellite Data  

Science.gov (United States)

Analyzing the magnitude of oil discharges from natural hydrocarbon seeps is important in improving our understanding of carbon contribution as oil migrates from deeper sediments to the water column, and then eventually to the atmosphere. Liquid hydrocarbon seepage in the deep water of the Gulf of Mexico (GOM) is associated with deep cutting faults, associated with vertical salt movement, that provide conduits for the upward migration of oil and gas. Seeps transform surface geology and generate prominent geophysical targets that can be identified on 3-D seismic data as seafloor amplitude anomalies maps that correlate with the underlying deep fault systems. Using 3D seismic data, detailed mapping of the northern GOM has identified more than 21,000 geophysical anomalies across the basin. In addition to seismic data, Synthetic Aperture Radar (SAR) images have proven to be a reliable tool for localizing natural seepage of oil. We used a Texture Classifier Neural Network Algorithm (TCNNA) to process more than 1200 SAR images collected over the GOM. We quantified more than 900 individual seep formations distributed along the continental shelf and in deep water. Comparison of the geophysical anomalies with the SAR oil slick targets shows good general agreement between the distributions of the two indicators. However, there are far fewer active oil slicks than geophysical anomalies, most of which are probably associated with gas seepage. By examining several sites where the location of active venting can be determined by submersibles observations, we found that the active oily vents are often spatially offset from the most intense geophysical targets (i.e. GC600, GC767, GC204, etc). In addition to the displacement of the oil by deep sea currents, we propose that during the 100K years of activity, the location of the vents on the seafloor probably migrate as carbonate cementation reduces the permeability of the upper sediment. Many of the geophysical targets may represent inactive relict sites rather than present day natural seeps of liquid or gaseous hydrocarbon.

Garcia-Pineda, O. G.; MacDonald, I. R.; Shedd, W.

2011-12-01

329

Partitioned-formula periodic tables for diamond hydrocarbons (diamondoids).  

Science.gov (United States)

Isomeric diamond hydrocarbons (diamondoids or polymantanes) with the same number n of adamantane units share the same molecular formula C(Q)(CH)(T)(CH(2))(S) and can be divided into valence isomers (denoted as Q-T-S) by partitioning the number C = Q + T + S of their carbon atoms according to whether they are quaternary, tertiary, or secondary. Vertices of dualists are the centers of adamantane units, and dualist edges connect vertices of adjacent adamantane units (sharing a chair-shaped hexagon). Dualists of diamondoids are hydrogen-depleted skeletons of staggered alkane or cycloalkane rotamers. Diamondoids with acyclic dualists can be classified as catamantanes, those having dualists with chair-shaped six-membered rings as perimantanes, and those having dualists with higher-membered rings that are not perimeters of hexagon-aggregates as coronamantanes. Diamondoids with n adamantane units may be classified into regular catamantanes when the molecular formula is C(4n+6)H(4n+12), and irregular polymantanes (catamantanes or perimantanes) when the number of carbon atoms is lower than 4n + 6. The derivation is presented of formula-periodic tables of regular and irregular diamondoids that allow a better understanding of the shapes and properties of these hydrocarbons for which many applications are predicted. PMID:23046064

Balaban, Alexandru T

2012-11-26

330

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

331

Long-distance migration: evolution and determinants  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Long distance migration has evolved in many organisms moving through different media and using various modes of locomotion and transport. Migration continues to evolve or become suppressed as shown by ongoing dynamic and rapid changes of migration patterns. This great evolutionary flexibility may seem surprising for such a complex attribute as migration. Even if migration in most cases has evolved basically as a strategy to maximise fitness in a seasonal environment, its occurrence and extent...

Alerstam, Thomas; Hedenstro?m, Anders; A?kesson, Susanne

2003-01-01

332

Metal-catalysed hydrocarbon oxidations  

Energy Technology Data Exchange (ETDEWEB)

This brief review describes recent findings by the author and his co-workers in the field of catalytic systems for the oxidation of saturated and aromatic hydrocarbons with molecular oxygen (from air), hydrogen peroxide and some other compounds. These systems are based on metal complexes as catalysts and often include obligatory co-catalysts, such as amino acids, nitrogen-containing bases or weak carboxylic acids. Some of these reactions can be considered as bio-mimetic models of corresponding oxidation processes occurring in living cells. In some cases, aerobic oxidations considered here occur in some cases under the action of light. Some features of these reactions and their mechanisms are presented and discussed. (author)

Shul' pin, G. [Russian Academy of Sciences, Semenov Institute of Chemical Physics, Moscow (Russian Federation)

2003-02-01

333

Fate of hydrocarbons in solids  

International Nuclear Information System (INIS)

This paper describes concepts, uses, and limitations of state-of-the-art mathematical environment pollutant fate modeling for use in hydrocarbon fate studies and analyses of environmental quality. Terrestrial chemicals fate modeling has traditionally been performed for three distinct sub-compartments: the land surface (of watershed); the unsaturated soil (or soil) zone; and the saturated (or groundwater) zone of the region. An evaluation of the fate of inorganic compounds in soil and groundwater requires a detailed consideration of the physical, chemical, and biological processes and reactions involved, such as complexation, absorption, precipitation, oxidation-reduction, chemical speciation, and biological reactions to determine the free metal concentration in soil solutions. These processes can affect such characteristics as species solubility, availability for biological uptake, physical transport, and corrosion potential

334

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.)

335

Photodynamic activity of polycyclic hydrocarbon  

Energy Technology Data Exchange (ETDEWEB)

Exposure of Paramecium caudatum to suspensions of 3,4-benzopyrene, followed by long wave ultraviolet irradiation, results in cell death at times related, inter alia, to carcinogen concentration. Prior to death, the cells exhibit progressive immobilization and blebbing. This photodynamic response is a sensitized photo-oxidation, as it is oxygen-dependent and inhibited by anti-oxidants, such as butylated hydroxy anisole and ..cap alpha..-tocopherol. Protection is also afforded by other agents, including Tweens, tryptophan and certain fractions of plasma proteins. No evidence was found for the involvement of peroxides or sulfhydryl groups. The correlations between photodynamic toxicity and carcinogenicity in a large series of polycyclic hydrocarbons is under investigation. Assays of air extracts for photodynamic toxicity are in progress. Significant toxicity has been found in oxygenated besides aromatic fractions.

Epstein, S.S.

1963-01-01

336

The Fate of Hydrocarbon Pollution in Kebnekaise, Arctic Sweden  

Science.gov (United States)

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.

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

2013-12-01

337

[Secondary myelodysplastic syndrome].  

Science.gov (United States)

Secondary or therapy related myelodysplastic syndrome may develop following treatment with alkylating agents and radiotherapy. The condition may also follow high dose therapy for malignant lymphomas. We describe two patients who developed secondary myelodysplasia. The first is a 76-year old female with a low grade lymphoma who developed pancytopenia with monosomy 7. Secondary myelodysplasia was diagnosed 24 months after treatment with chlorambucil (total dose of 900 mg) and 12 months after treatment with trophosphamide (total dose of 24 g). The second patient was a 48-year old male who underwent autologous bone marrow transplantation for a relapsed low grade lymphoma. Following autografting he had persistent anemia and trombocytopenia. Secondary myelodysplastic syndrome with complex karyotype was diagnosed 54 months after high dose therapy. He died nine months later of bone marrow failure. PMID:9441464

Shammas, F V; Heikkilä, R

1997-11-30

338

Polycyclic aromatic hydrocarbons in background podzolic and gleyic peat-podzolic soils  

Science.gov (United States)

The qualitative and quantitative composition of polycyclic aromatic hydrocarbons (PAHs) has been determined in the background podzolic and gleyic peat-podzolic soils of the middle and northern taiga zones of northeastern Europe using the methods of highly efficient liquid chromatography and chromato-mass spectrometry. The distribution of polyarenes in the soil profiles follows the eluvial-illuvial pattern. Organic and illuvial horizons are the biogeochemical barriers for PAHs migrating in the soils. The revealed regularities of the accumulation and redistribution of PAHs in the soil profiles are in agreement with the character of the soil-forming processes in the northern and middle taiga zones.

Gabov, D. N.; Beznosikov, V. A.; Kondratenok, B. M.

2007-03-01

339

Effects of freeze/thaw cycles on hydrocarbon contaminants in the active layer  

International Nuclear Information System (INIS)

A study of the movement of hydrocarbon contaminants in ice and frozen soil was undertaken to determine the effects of freeze/thaw cycles on the behaviours of diesel fuel in the active layer. Other physical processes governing movement in non-frozen porous media were held constant in a carefully controlled environment in order to isolate and examine the effects of freezing and thawing on contaminant migration. Field studies in the Arctic and Antarctic were to be used to corroborate laboratory studies. A review of relevant literature and experiments was presented, including Arctic and Antarctic studies. 20 refs., 1 fig

340

ESCAP migration study gathers momentum.  

Science.gov (United States)

A comparative study is being conducted in the ESCAP (Economic and Social Commission for Asia and the Pacific) region on the relationships of migration and urbanization to development. The 1st stage of the study will entail the preparation of country reports on the census analysis of migration, urbanization and development. The 2nd stage will involve preparation of a series of national migration surveys. The 3rd phase will involve assisting member governments to formulate a comprehensive population redistribution policy as part of their national development planning. 1st-phase country reports have been completed in Sri Lanka, South Korea, the Philippines, and Indonesia. Migration in Sri Lanka has largely been rural-to-rural with little urbanization so far. The picture in South Korea has been the opposite, with rapid urbanization in the 1960s and 1970s; the government is hoping to divert some population to smaller cities away from Seoul. The pattern in the Philippines is 1 of urban primacy with the metropolis of Manila accounting for over 1/3 of the country's total population. Indonesia is characterized by a dense heartland in the Java-Bali regions. However, the rate of urbanization here has been slower. Migrants in all the countries studied are preponderantly young. The sex differential varies from country to country. The influence of migration on subsequent fertility is unknown. PMID:12262021

1980-01-01

 
 
 
 
341

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

342

Detection of irradiated meats by hydrocarbon method  

International Nuclear Information System (INIS)

Meats, for example, lamb, razorback, wild duck and turkey were irradiated by gamma ray, and the amounts of hydrocarbons formed from fatty acids were measured. Since C20:0 was found from wild duck and turkey. C1-18:1 was recommended for internal standard. Good correlation was found between the amount of hydrocarbons and the doses of gamma irradiation. This study shows that such hydrocarbons induced after radiation procedure as C1,7-16:2, C8-17:1, C1-14:1, and C15:0 may make it possible to detect irradiated lamb, razorback, wild duck and turkey. (author)

343

Waste Plastic Converting into Hydrocarbon Fuel Materials  

Energy Technology Data Exchange (ETDEWEB)

The increased demand and high prices for energy sources are driving efforts to convert organic compounds into useful hydrocarbon fuels. Although much of this work has focused on biomass, there are strong benefits to deriving fuels from waste plastic material. Natural State Research Inc. (NSR) has invented a simple and economically viable process to decompose the hydrocarbon polymers of waste plastic into the shorter chain hydrocarbon of liquid fuel (patent pending). The method and principle of the production / process will be discussed. Initial tests with several widely used polymers indicate a high potential for commercialization.

Sarker, Moinuddin; Mamunor Rashid, Mohammad; Molla, Mohammad

2010-09-15

344

Selective photooxidation of hydrocarbons in zeolites by oxygen  

Energy Technology Data Exchange (ETDEWEB)

A selective photooxidation process for the conversion of hydrocarbon molecules to partially oxygenated derivatives, which comprises the steps of adsorbing a hydrocarbon and oxygen onto a dehydrated zeolite support matrix to form a hydrocarbon-oxygen contact pair, and subsequently exposing the hydrocarbon-oxygen contact pair to visible light, thereby forming a partially oxygenated derivative.

Frei, Heinz (Berkeley, CA); Blatter, Fritz (Berkeley, CA); Sun, Hai (Berkeley, CA)

1998-01-01

345

A reassessment of models for hydrocarbon generation in the Khibiny nepheline syenite complex, Kola Peninsula, Russia  

Science.gov (United States)

Although hydrocarbon-bearing fluids have been known from the alkaline igneous rocks of the Khibiny intrusion for many years, their origin remains enigmatic. A recently proposed model of post-magmatic hydrocarbon (HC) generation through Fischer-Tropsch (FT) type reactions suggests the hydration of Fe-bearing phases and release of H 2 which reacts with magmatically derived CO 2 to form CH 4 and higher HCs. However, new petrographic, microthermometric, laser Raman, bulk gas and isotope data are presented and discussed in the context of previously published work in order to reassess models of HC generation. The gas phase is dominated by CH 4 with only minor proportions of higher hydrocarbons. No remnants of the proposed primary CO 2-rich fluid are found in the complex. The majority of the fluid inclusions are of secondary nature and trapped in healed microfractures. This indicates a high fluid flux after magma crystallisation. Entrapment conditions for fluid inclusions are 450-550 °C at 2.8-4.5 kbar. These temperatures are too high for hydrocarbon gas generation through the FT reaction. Chemical analyses of rims of Fe-rich phases suggest that they are not the result of alteration but instead represent changes in magma composition during crystallisation. Furthermore, there is no clear relationship between the presence of Fe-rich minerals and the abundance of fluid inclusion planes (FIPs) as reported elsewhere. ? 13C values for methane range from - 22.4‰ to - 5.4‰, confirming a largely abiogenic origin for the gas. The presence of primary CH 4-dominated fluid inclusions and melt inclusions, which contain a methane-rich gas phase, indicates a magmatic origin of the HCs. An increase in methane content, together with a decrease in ? 13C isotope values towards the intrusion margin suggests that magmatically derived abiogenic hydrocarbons may have mixed with biogenic hydrocarbons derived from the surrounding country rocks.

Beeskow, B.; Treloar, P. J.; Rankin, A. H.; Vennemann, T. W.; Spangenberg, J.

2006-10-01

346

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

Science.gov (United States)

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

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

2014-10-30

347

SEMS vs cSEMS in duodenal and small bowel obstruction: High risk of migration in the covered stent group  

Digital Repository Infrastructure Vision for European Research (DRIVER)

AIM: To compare clinical success and complications of uncovered self-expanding metal stents (SEMS) vs covered SEMS (cSEMS) in obstruction of the small bowel. METHODS: Technical success, complications and outcome of endoscopic SEMS or cSEMS placement in tumor related obstruction of the duodenum or jejunum were retrospectively assessed. The primary end points were rates of stent migration and overgrowth. Secondary end points were the effect of concomitant biliary drainage on migration rate a...

Waidmann, Oliver; Trojan, Jo?rg; Friedrich-rust, Mireen; Sarrazin, Christoph; Bechstein, Wolf Otto; Ulrich, Frank; Zeuzem, Stefan; Albert, Jo?rg Gerhard

2013-01-01

348

A Forgotten Migration and Citizenship Experience: First Generation Immigrant Women and The Netherlands Union of Women from Turkey  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Despite acknowledging the feminization of immigration there are a few studies giving immigrant and ethnic minority women greater visibility within receiving country context and using gender as an analytic concept in migration researches. Particularly, there is a tendency that women’s migration has still been acknowledged as “dependant” or “secondary” migratory movement in guest worker regimes’ traditional “family reunion” schemas and issues such as immigrant women’s particip...

Ece Öztan

2010-01-01

349

International Migration, Remittances and Development  

Directory of Open Access Journals (Sweden)

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. 

Hasan Mahmud

2009-02-01

350

Nonequilibrium migration in human history.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A nonequilibrium migration model is proposed and applied to genetic data from humans. The model assumes symmetric migration among all possible pairs of demes and that the number of demes is large. With these assumptions it is straightforward to allow for changes in demography, and here a single abrupt change is considered. Under the model this change is identical to a change in the ancestral effective population size and might be caused by changes in deme size, in the number of demes, or in t...

Wakeley, J.

1999-01-01

351

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

352

Retirement migration and military retirement  

International Nuclear Information System (INIS)

This report addresses questions relevant to a socioeconomic assessment system for southern Nevada. They point to an understanding of the magnitude of impacts which may occur if the Yucca Mountain Project were to affect the decision-making process which leads these groups to migrate to southern Nevada. This is an important but somewhat elusive topic lacking in standard data sources. However, the topic may be addressed and analyzed systematically. This report presents the results of efforts to develop a data base and begin development of a model to address the migration, income and expenditure dimensions of these groups. 1 fig., 62 tabs

353

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)

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

Assouline, F.

2001-07-01

354

Review on the origin of oil and hydrocarbon gases within our solar system: biogenic or abiogenic?  

Science.gov (United States)

The petroleum hydrocarbons (oil like components and gas) and kerogen macromolecule are abundant within the extraterrestrial atmospheric particles, as reservoir of lakes and oceans or in hydrate forms, and within various carbonaceous chondrites (from asteroid belts, comets, and planets/moons), and as solid residue within the planets or moons within and outside our Solar System. Some of the important occurrences of petroleum hydrocarbons are: (a) the cup-like craters and large lakes, in the atmosphere within two moons of Saturn (Hyperion and Titan), and possibly also in Saturn's rings; (b) solid organic complexes with aromatic and aliphatic units within Iapetus and many bodies in the outer Solar System; (c) abundance of water, methane, gas hydrates within Mars; (d) remnant of nannofossils, kerogen-like geopolymers, and oil-like components within most of the CM, C1, and C2 carbonaceous chondrites. These discoveries clearly rekindled the very old debate over the biogenic or abiogenic origin on the genesis of these hydrocarbons. Several theories are prevalent for the abiogenic origin of petroleum: formation of gas by mantle decompression and thermal tsunami; various deep polymerization processes in the upper mantle gases through inorganic processes; gases evolved from a hot deep biosphere in the mantle, migration through deep-seated faults, and eventual polymerization of gases to heavier hydrocarbons. Most prevalent ideas of the origin of petroleum pool within various stratigraphic intervals in the terrestrial environment are overwhelmingly connected to the thermal degradation of macromolecular kerogen of biological entities. The current publication illustrated both these views on the genesis of petroleum hydrocarbons within carbonaceous chondrites that could be derived from other planets or moons within our Solar System and the asteroid belts and beyond.

Mukhopadhyay, Prasanta K.; Mossman, David J.; Ehrman, James M.

2010-09-01

355

Hydrocarbon detection utilizing neutron borehole measurements  

International Nuclear Information System (INIS)

This invention relates in general to neutron logging of subsurface earth formations and, in particular, to apparatus and procedures for providing indications of the presence of hydrocarbons in the pores of these formations. (U.K.)

356

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)

357

Using microorganisms to aid in hydrocarbon degradation  

Energy Technology Data Exchange (ETDEWEB)

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 (CO[sub 2] 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.

Black, W.; Zamora, J. (Middle Tennessee State Univ., Murfreesboro (United States))

1993-04-01

358

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

359

Biodegradation of Petroleum Hydrocarbons in Soil  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

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

2003-01-01

360

The future of oil and hydrocarbon man  

CERN Document Server

Man appeared on the planet about four million years ago, and by 1850 numbered about one billion Ten came Hydrocarbon man. World population has since increased six-fold. After the oil price shocks of the 1970s, people asked "when will production peak?". It is not easy to answer this question because of the very poor database. Reserves and the many different hydrocarbon categories are poorly defined, reporting practices are ambiguous, revisions are not backdated...

Campbell, Colin

1999-01-01

 
 
 
 
361

Acquired and Innate Immunity to Polyaromatic Hydrocarbons  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Polyaromatic hydrocarbons are ubiquitous environmental pollutants that are potent mutagens and carcinogens. Researchers have taken advantage of these properties to investigate the mechanisms by which chemicals cause cancer of the skin and other organs. When applied to the skin of mice, several carcinogenic polyaromatic hydrocarbons have also been shown to interact with the immune system, stimulating immune responses and resulting in the development of antigen specific T-cell mediated immunity...

Yusuf, Nabiha; Timares, Laura; Seibert, Megan D.; Xu, Hui; Elmets, Craig A.

2007-01-01

362

Monitoring of microbial hydrocarbon remediation in the soil  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Bioremediation of hydrocarbon pollutants is advantageous owing to the cost-effectiveness of the technology and the ubiquity of hydrocarbon-degrading microorganisms in the soil. Soil microbial diversity is affected by hydrocarbon perturbation, thus selective enrichment of hydrocarbon utilizers occurs. Hydrocarbons interact with the soil matrix and soil microorganisms determining the fate of the contaminants relative to their chemical nature and microbial degradative capabilities, respectively....

Chikere, Chioma Blaise; Okpokwasili, Gideon Chijioke; Chikere, Blaise Ositadinma

2011-01-01

363

Coupled oxidation and enhanced bioremediation pilot test : petroleum hydrocarbon plume migrating in fractured rock  

Energy Technology Data Exchange (ETDEWEB)

This presentation described a coupled oxidation and enhanced bioremediation pilot test conducted to examine the hydraulic characteristics and geochemical effects of chemical injection. Coupled oxidation was used along with a plume stabilization strategy consisting of integrated physical removal, in situ chemical oxidation (ISCO) and the use of bio-attenuation zones. The pilot program demonstrated that an understanding of the fractured bedrock hydrogeology was needed in order to successfully use the method. Injection chemicals consisted of PermeOx Plus and Klozur OBC. The chemicals were selected for their stability and low soil oxidant demands. Monitoring points were installed, and core materials were measured for oxidant demand. Performance monitoring was then continued for 3 months after the injection phase. Hydrogeologic profiles were included, and percentages of Proteobacteria were documented. Results of the pilot test demonstrated that hydraulic effects were local and short-lived, while geochemical and biological effects were broad and long-lived. It was concluded that both chemicals effectively reduced contaminant concentrations. tabs., figs.

Yeske, B.; Ellard, B. [UFA Co-operative Ltd., Calgary, AB (Canada); Studer, J.E. [InfraSUR LLC, Albuquerque, NM (United States); Sterling, S. [Stantec Consulting Ltd., Surrey, BC (Canada); Nevokshonoff, B. [Sequoia Environmental Remediation Inc., Calgary, AB (Canada)

2007-07-01

364

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

365

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

Energy Technology Data Exchange (ETDEWEB)

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.

Horstad, I.

1995-12-31

366

Selective enrichments induced by thermo gravitational diffusion in porous medium on hydrocarbon species of crude oil; the specific case of paraffin isomers  

Energy Technology Data Exchange (ETDEWEB)

It has been experimentally shown that differential segregations can be developed, by thermogravitational diffusion in porous medium, on the various hydrocarbons in a crude oil. The different classes of hydrocarbons present specific global migrations which appear to be dependent on the molecular structure and mass. A special study of the molecular structure dependence has been performed on paraffinic isomers: the linear types of molecules are the most strongly differentiated, and molecules branched in position 3 are less differentiated (ante-isoalkanes). (authors). 27 refs., 5 figs., 5 tabs.

Costeseque, P.; Riviere, E. [Toulouse-3 Univ., 31 (France); El Maataoui, M. [Universite Moulay Ismail, Meknes (Morocco)

1994-12-31

367

Polycyclic hydrocarbons - occurrence and determination  

International Nuclear Information System (INIS)

Polycyclic aromatic hydrocarbons (PAHs) are a special group of atmospheric contaminants included in the persistent toxic substances (PTS) and also in the volatile organic compounds (VOC) groups. PAHs are present in the atmosphere and their origin can be due to anthropogenic activities. The main source of emission of PAH is the combustion of fossil fuels. Their specific characteristics, high volatility, mutagenic and carcinogenic power, easily transportable for long distances with the wind, make them important contaminants despite of the fact that they are present at very low concentrations. The report provides a review of main analytical methods applied in the determination of PAH in air. Special attention was devoted to heterocyclic PAH which contain one or more heteroatom (sulphur, oxygen, nitrogen) in the multiple-fused ring. The presence of heterocyclic PAH requires very complex, laborious and long lasting sample separation methods before analysis. In some cases, application of different temperature programs in gas chromatography allows to determine PAH and heterocyclic PAH in gaseous samples without sample pretreatment. Gas chromatography methods for the determination of PAH and heterocyclic PAH in the gas from combustion of light heating oil has been optimized. (author)

368

Fischer-Tropsch catalysts for the production of hydrocarbon fuels with high selectivity.  

Science.gov (United States)

Fischer-Tropsch synthesis is a key reaction in the utilization of non-petroleum carbon resources, such as methane (natural gas, shale gas, and biogas), coal, and biomass, for the sustainable production of clean liquid fuels from synthesis gas. Selectivity control is one of the biggest challenges in Fischer-Tropsch synthesis. This Minireview focuses on the development of new catalysts with controllable product selectivities. Recent attempts to increase the selectivity to C5+ hydrocarbons by preparing catalysts with well-defined active phases or with new supports or by optimizing the interaction between the promoter and the active phase are briefly highlighted. Advances in developing bifunctional catalysts capable of catalyzing both CO hydrogenation to heavier hydrocarbons and hydrocracking/isomerization of heavier hydrocarbons are critically reviewed. It is demonstrated that the control of the secondary hydrocracking reactions by using core-shell nanostructures or solid-acid materials, such as mesoporous zeolites and carbon nanotubes with acid functional groups, is an effective strategy to tune the product selectivity of Fischer-Tropsch synthesis. Very promising selectivities to gasoline- and diesel-range hydrocarbons have been attained over some bifunctional catalysts. PMID:24339240

Zhang, Qinghong; Cheng, Kang; Kang, Jincan; Deng, Weiping; Wang, Ye

2014-05-01

369

Laser spectroscopy of hydrocarbon radicals  

Energy Technology Data Exchange (ETDEWEB)

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.

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

1993-12-01

370

A Psychological Journey Through Migration  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Psychological dimension is emphasized in different approaches and languages over migration in a review of its reasons and circumstances, analyzing the person “decontextualization”, his rupture, the transcultural risk and the migratory trauma that may occur. The concept of disease and illness are mentioned as well as the concept of “alterity”, the cultural dimension in the therapeutic relation ...

Maria Inês Dias Silva

2014-01-01

371

Tritium migration in tritiated anisole  

International Nuclear Information System (INIS)

Experimental studies have been reported of reactions involving the phenyl cation as an intermediate where the results obtained are most easily explained in terms of 1,2 hydrogen shifts in the intermediate ion. Our purpose here is to present an alternative interpretation, supported by MINDO/3 calculations, that avoids the implied conclusion that the barrier to hydrogen migration is in fact small

372

VORTEX MIGRATION IN PROTOPLANETARY DISKS  

International Nuclear Information System (INIS)

We consider the radial migration of vortices in two-dimensional isothermal gaseous disks. We find that a vortex core, orbiting at the local gas velocity, induces velocity perturbations that propagate away from the vortex as density waves. The resulting spiral wave pattern is reminiscent of an embedded planet. There are two main causes for asymmetries in these wakes: geometrical effects tend to favor the outer wave, while a radial vortensity gradient leads to an asymmetric vortex core, which favors the wave at the side that has the lowest density. In the case of asymmetric waves, which we always find except for a disk of constant pressure, there is a net exchange of angular momentum between the vortex and the surrounding disk, which leads to orbital migration of the vortex. Numerical hydrodynamical simulations show that this migration can be very rapid, on a timescale of a few thousand orbits, for vortices with a size comparable to the scale height of the disk. We discuss the possible effects of vortex migration on planet formation scenarios.

373

Les questions de migrations internationales  

Science.gov (United States)

International migrations have growing implications for both countries of origin and countries of destination. In the latter, the presence of foreigners and of members of their families today creates problems of integration, causes argument and brings mounting xenophobia. Paralleling political, economic and social measures taken by public authorities to respond to these difficulties, education needs to assist in defusing the resulting social tensions by preparing the minds of learners and helping to develop new attitudes. In particular, when educational programmes address questions of international migration, these should be treated in the framework of historical evolution so that their real significance and their true temporal and spatial dimensions become apparent. It is also important that the growing interdependence between countries should be made plain, that national history should be placed in its international context, and that the true consequences of these developments should be made clear. In this context, learners need to be acquainted with Human Rights, thereby stressing universal moral values and the role of the individual. Lastly, questions relating to international migration are usually presented in the media in a selective and partial manner, and the young people who take in this information often accept the hasty judgments which are made of situations as proven facts. This is why all teaching about international migration needs to be considered or reconsidered in the light of the complementary or competing actions of the media.

Samman, Mouna Liliane

1993-03-01

374

Whale Migration: The Long Journey  

Science.gov (United States)

This data tip from Bridge, the Ocean Sciences Education Teacher Resource Center archive, discusses the migration of the California gray and the Northern right whales. The data exercise asks students to plot right whale sightings off Georgia and Florida. Students can also answer questions about whale behavior.

375

Long migration flights of birds  

Science.gov (United States)

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.

Denny, Mark

2014-05-01

376

Liquid chromatography in migration studies  

International Nuclear Information System (INIS)

Liquid chromatography ahs been suggested as a facile experimental technique to determine important physico-chemical properties, as permeability, porosity, dispersion-, diffusion-, and sorption charcteristics for geological material as chalk samples. The feasibility of the trechnique as a rapid method to evaluate the possible influence of changes in ground water composition on the migration behavior of radionuclides has been demonstrated

377

Medical migration within Europe: opportunities and challenges.  

Science.gov (United States)

The free movement of European citizens to live and work within the European Union (EU) is one of the fundamental pillars of the European single market. Recent EU legislation on the recognition of professional qualifications (to take effect January 2016) updates the framework within which doctors and others can migrate freely between EU member states to practise their profession. UK organisations lobbied extensively to change aspects of the original proposals, in particular those that threatened to 'water down' public protection in the interest of free movement. The legislation finally adopted significantly increases safeguards for patients and the public. The revised law covers the rules to be applied by regulators on (for example) assuring language competence, warning 'blacklists' of practitioners subject to sanctions, 'fast track' registration based on mutual recognition of professional qualifications, agreed minimum education and training requirements for mutual recognition, and encouragement of continuing professional development. Drafting of detailed secondary legislation is ongoing and poses opportunities and challenges for patient safety, quality of care and transparency. PMID:25468849

Ling, Kate; Belcher, Paul

2014-12-01

378

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

Science.gov (United States)

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

Weber, A; Hörmann, G

2011-05-01

379

Mediterranean Migrations: Regionalisms Versus Globalisation  

Directory of Open Access Journals (Sweden)

Full Text Available This paper challenges the claim of globalisation as a cause ofimmigration into Southern Europe and, on an empirical basis, identifies regionalisation as being the primary issue, along with networked migratory patterns. However, the changing patterns of immigration do present challenges to both state and society. It is argued here that recent policy responses in Portugal, Italy and Spain have been inconsistent and irrational – reflecting more the ‘securitisation’ of migration than European reality. Earlier policy innovations are identified, by country and date: most of these have now been abandoned. It is suggested that all of Southern Europe has converged onto a statist, restrictionist model of immigration control that was formerly held only by Greece. The principal characteristics of this model are outlined, along with a migration flowchart and indicative data for migrant flows and sub-flows in Italy and Spain. In the final section, I try to show that the needs of the economy cannot be predicted, immigration cannot becontrolled in the manner currently being enforced across Southern Europe, and attempts to do so will damage rather than improve economic productivity and growth. The concept of an accomodating immigration policy is advanced, whereby the state tries to manage the needs of both employers and potential migrants. Six guidelines for policy development are suggested – most of which have alreadybeen successfully carried out in the European Union. These are the following: migration in order to find a job; circular cross-border migration; EU level negotiation of readmission agreements; the need for a variety of migration-for-employment schemes; legal residence should not depend upon continuity of employment; and discreet legalisation will still be needed in Southern Europe.

Martin Baldwin-Eduards

2004-06-01

380

Migrating landfill gas proves challenging  

Energy Technology Data Exchange (ETDEWEB)

Located in the San Fernando Valley at the foothills of the San Gabriel mountains, the 41-acre Sheldon-Arleta Landfill originated as one of many gravel pits in the area and was operated by CalMat as a gravel quarry pit from the mid 1950s until 1962. In 1967, methane gas was detected in the residential dwellings located across from the landfill along Sharp Street. Three landfill gas wells were installed at the north corner of the landfill to control off-site migration of landfill gas. Landfill gas, through diffusion, saturates soil pores below and around the landfill. Groundwater serves as an effective barrier to landfill gas migration. Thus a rising water table mobilizes landfill gas from soil pores. Where that gas cannot be effectively collected, off-site migration will occur. The solution to ensuring public safety is to collect landfill gas on-site before it escapes the influence of gas collection wells. This may require complete reevaluation of an existing landfill gas collection system and potential renovation to collect greater quantities of land-fill gas. Cost-effective implementation of this strategy calls for two gas collection systems: one for collection of methane-rich landfill gas for electrical generation and resource recovery, and the other to control off-site migration of landfill gas through on-site combustion. Installation/upgrades of the foregoing solutions are long-term options. For the short-term immediate mitigation of high landfill gas migration, installation of a passive vent system was necessary with the option of active extraction. However, one must recognize that the public is ultimately better served by controlling landfill gas on-site before it approaches dangerous off-site levels.

Dobrowolski, J.G.; Dellinger, A.S. [City of Los Angeles Bureau of Sanitation, CA (United States)

1994-12-01

 
 
 
 
381

Remote sensing and monitoring the experiments of diesel and JP-5 fuel migrations in soils  

International Nuclear Information System (INIS)

This paper reports on a large-scale three-dimensional experimental study of JP-5 and diesel fuel migration in sand and soil carried out at a laboratory site in the Mojave desert, California. The CATLAS, a computerized hydrocarbon vapor monitoring system, scanned 56 MOS hydrocarbon vapor sensors installed in a 14 ft x 12 ft x 10 ft test chamber. The results were stored and transferred via two modems through telephone lines to the computer in the main office on a daily basis. Data processing and trend analysis were performed by the computer and trips to the site were made only when found necessary from an analysis of the data. Three tests featuring the movements of diesel fuel in sand, diesel fuel in soil and JP-5 fuel in sand were conducted. Each test lasted for approximately 30 days. Temporal vapor concentration contour maps at different elevations inside the chamber were generated

382

Theoretical aspects of studying the migration processes  

Directory of Open Access Journals (Sweden)

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.

Dilfuza Rasulova

2010-02-01

383

EU migration policy: needs and perspectives  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper examines EU's migration policy development. The paper presents a short review of literature and current discussions about the appropriate balance of powers between EU institutions and member states in migration issues. The paper argues that mechanical shift of the responsibility from national to supranational agencies, will not provide satisfactory solutions to the challenges related to migration issues both within the EU area and the world in general. Migration is changing our ...

Tomilinas, Tomas

2008-01-01

384

La migration irrégulière en droit syrien  

Digital Repository Infrastructure Vision for European Research (DRIVER)

La migration irrégulière constitue à l'heure actuelle un phénomène qui ne cesse de s'accroître à l’échelle internationale, et surtout en Europe. C'est la raison pour laquelle la majorité des Etats européens ont modifié leurs lois concernant la migration et l'immigration pour mieux affronter ce nouveau défi et que des propositions telles que « la migration circulaire » tentent de faire avancer le débat. En Syrie, la migration irrégulière ne constituait pas vraiment un ph?...

Saleh, Fawaz

2008-01-01

385

Secondary emission gas chamber  

CERN Document Server

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.

In'shakov, V; Skvortsov, V

2014-01-01

386

Secondary coolant purification system  

International Nuclear Information System (INIS)

The present invention combines the attributes of volatile chemical addition, continuous blowdown, and full flow condensate demineralization. During normal plant operation (defined as no primary to secondary leakage) condensate from the condenser is pumped through a full flow condensate demineralizer system by the condensate pumps. Volatile chemical additions are made. Dissolved and suspended solids are removed in the condensate polishers by ion exchange and/or filtration. At the same time a continuous blowdown of approximately 1 percent of the main steaming rate of the steam generators is maintained. Radiation detectors monitor the secondary coolant. If these monitors indicate no primary to secondary leakage, the blowdown is cooled and returned directly to the condensate pump discharge. If one of the radiation monitors should indicate a primary to secondary leak, when the temperature of the effluent exiting from the blowdown heat exchanger is compatible with the resin specifications of the ion exchangers, the bypass valve causes the blowdown flow to pass through the blowdown ion exchangers

387

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

388

Migration on Wings Aerodynamics and Energetics  

CERN Document Server

This book is an effort to explore the technical aspects associated with bird flight and migration on wings. After a short introduction on the birds migration, the book reviews the aerodynamics and Energetics of Flight and presents the calculation of the Migration Range. In addition, the authors explains aerodynamics of the formation flight and finally introduces great flight diagrams.

Kantha, Lakshmi

2012-01-01

389

Volatile hydrocarbons inhibit methanogenic crude oil degradation  

Directory of Open Access Journals (Sweden)

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.

AngelaSherry

2014-04-01

390

Measurements of ambient hydrocarbons and carbonyls in the Pearl River Delta (PRD), China  

Science.gov (United States)

Measurements of 47 hydrocarbons and 3 carbonyls were performed at six sites in July 2006 and in October-November 2008 in Pearl River Delta (PRD), China. The distribution of volatile organic compound (VOC) concentrations and compositions at different sites revealed photochemical losses of hydrocarbons and secondary formation of carbonyls. Carbonyls were shown to be an important contributor to OH loss rates and ozone formation potentials. Correlations between VOCs were used to identify the sources of VOC species. Liquefied petroleum gas (LPG) is an important contributor in Guangzhou. Vehicle emissions were the dominant sources of C4-C5 alkenes (except isoprene), whereas industrial and/or solvent use accounted for a significant fraction of aromatic concentrations. Ethylbenzene/m, p-xylene ratios accurately described ozone formation at all sites except a site located upwind of Guangzhou in 2008.

Yuan, Bin; Chen, Wentai; Shao, Min; Wang, Ming; Lu, Sihua; Wang, Bin; Liu, Ying; Chang, Chih-Chung; Wang, Boguang

2012-10-01

391

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)

392

Nanoparticles migration in fractured rocks and affects on contaminant migration  

Science.gov (United States)

In previous studies, the transport behavior of artificial (gold and latex) and natural (smectite clay) colloids, within a planar fracture in crystalline rock, was analyzed. In order to better understand the effects of colloid size, shape and surface charge on nanoparticle migration and especially on filtration processes on natural rock surfaces, different clay colloids and oxide nanoparticles were selected and their transport studied as a function of the residence time. In all the cases, (a fraction of) the nanoparticles travelled in the fracture as fast as or faster than water (with a retardation factor, Rf ? 1) and the observed Rf, was related to the Taylor dispersion coefficient, accounting for colloid size, water velocity and fracture width. However, under most of the cases, in contrast to the behavior of a conservative tracer, colloids recovery was much lower than 100 %. Differences in recovery between different nanoparticles, under similar residence times, were analyzed. In order to evaluate the possible consequences, on contaminant migration, of the presence of nanoparticles in the system, transport tests were carried out with both colloids and sorbing radionuclides. The overall capacity for colloids of enhancing radionuclide migration in crystalline rock fractures is discussed. Acknowledgments: The research leading to these results received funding from EU FP7/2007-2011 grant agreement Nº 295487 (BELBAR, Bentonite Erosion: effects on the Long term performance of the engineered Barrier and Radionuclide Transport) and by the Spanish Government under the project NANOBAG (CTM2011-2797).

Missana, Tiziana; Garcia-Gutierrez, Miguel; Alonso, Ursula

2014-05-01

393

A study of a spot migration in two contact binaries: KIC 2159783 and KIC 6118779  

Science.gov (United States)

Data of contact binaries, provided by the Kepler spacecraft, can be successfully applied to estimate the parameters of a binary system only if its light curve has a flat-bottom secondary minimum. The derived system parameters are accurate enough to search for a spot migration using the Wilson-Devinney code. For binaries with a regular activity (e.g. KIC 6118779) the numerical spot modeling is consistent with a model-independent light curve morphology analysis. Finally, we proved that spot migration cycles established by the Wilson-Devinney modeling correspond to the O'Connell effect and maxima separation methods.

Debski, B.; Baran, A.; Zola, S.

2014-03-01

394

Mississippi River and Sea Surface Height Effects on Oil Slick Migration  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Millions of barrels of oil escaped into the Gulf of Mexico (GoM) after the 20 April, 2010 explosion of Deepwater Horizon (DH). Ocean circulation models were used to forecast oil slick migration in the GoM, however such models do not explicitly treat the effects of secondary eddy-slopes or Mississippi River (MR) hydrodynamics. Here we report oil front migration that appears to be driven by sea surface level (SSL) slopes, and identify a previously unreported effect of the MR plume: under condit...

Falcini, Frederico; Jerolmack, Douglas J.; Buongiorno Nardelli, Bruno

2012-01-01

395

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

396

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

Energy Technology Data Exchange (ETDEWEB)

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)

Lookman, R.; Vanermen, G.; Van De Weghe, H.; Gemoets, J. [Vito, Mol (Belgium); Van der Sterren, G.; Alphenaar, A. [TTE, Deventer (Netherlands)

2005-07-01

397

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)

398

Tritium dynamics within secondary contaminant sources in fractured shale bedrock  

International Nuclear Information System (INIS)

The disposal of low-level radioactive waste at Oak Ridge National Laboratory (ORNL) has historically involved shallow land burial via pits and trenches. For the past several decades, contaminants have been migrating from the primary waste trenches into the underlying saturated zone, which is composed primarily of fractured shale bedrock. A portion of these contaminant plumes have been moving quickly along fast-flowing fractures, while other portions of the plumes have been slowly migrating into the surrounding bedrock matrix. Contaminant migration into the matrix is both beneficial and problematic. Matrix storage alleviates the potential of large contaminant discharges from the primary waste trenches into the groundwater, yet it creates a secondary contaminant source that is difficult to remediate. The contaminant tritium is of particular concern because of the large inventories present in existing waste sites and because of its high mobility from the primary waste source. Waste Area Grouping 5 (WAG 5) at ORNL is known to be a significant contributor of tritum contamination to the local watershed. The total yearly tritium discharge from this region is on the order of many thousands of curies. Remedial action at WAG 5 is hampered by inaccurate risk assessment that is associated with the poorly defined source terms of the contaminated bedrock. The authors objectives were to (a) quantify the rate of tritum storage and depletion within secondary sources at WAG 5 and (b) dithin secondary sources at WAG 5 and (b) define the importance of primary and secondary sources of tritium to contamination discharged to the streams along the perimeter of WAG 5

399

Conversion of Ethanol to Hydrocarbons on Hierarchical HZSM-5 Zeolites  

Energy Technology Data Exchange (ETDEWEB)

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.

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

2014-12-15

400

Syngas Upgrading to Hydrocarbon Fuels Technology Pathway  

Energy Technology Data Exchange (ETDEWEB)

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.

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

2013-03-31