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1

Flow regime associated with vertical secondary migration  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Secondary migration is defined as the movement of hydrocarbons through relatively permeable rocks from source to trap: a two-phase flow within a porous medium. Depending on the geometry and capillary pressure distributions of carrier beds, secondary migration has both vertical and lateral components. The present paper focuses on that part of the migration where the movement is mainly vertical. Its objective is to propose a description of the dynamics governing the vertical part of secondary m...

Vasseur, Guy; Xiaorong, Luo; Yan, Jianzhao; Loggia, Didier; Toussaint, Renaud; Schmittbuhl, Jean

2013-01-01

2

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

3

Role of diffusion in primary migration of hydrocarbons  

Energy Technology Data Exchange (ETDEWEB)

The following effective diffusion coefficients D(cm/sup 2//sec) were determined for the diffusion of light hydrocarbons through the water-saturated pore space of shales: methane (2.12 x 10/sup -6/), ethane (1.11 x 10/sup -6/), propane (5.55 x 10/sup -7/), iso-butane (3.75 x 10/sup -7/), n-butane (3.01 x 10/sup -7/), n-pentane (1.57 x 10/sup -7/), n-hexane (8.20 x 10/sup -8/), n-heptane (4.31 x 10/sup -8/), and n-decane (6.08 x 10/sup -9/). On the basis of these new data, a deterministic, dynamic model was set up to simulate the diffusive transport of light hydrocarbons (C/sub 1/ to C/sub 10/) from source rocks. For eight documented source-rock units, representing a wide range of geologic conditions (maturities of 0.40 to 1.35% mean vitrinite reflectance; oil- to gas-prone kerogens), the cumulative amounts of hydrocarbons escaping with time were calculated. The origin of hydrocarbon accumulations with high gas-to-oil ratios in low-mature sediments in geologically young basins (early gases and condensates) can be explained by a early phase of primary migration predominantly based on diffusion. Compositional trends among reservoir gases of several multiple-pay gas fields in Louisiana represent evidence for diffusive transport of hydrocarbons. Diffusion of light hydrocarbons in the subsurface can also have economically adverse effects. Large gas accumulations can persist through extended periods of geological time only as dynamic systems reaching some kind of steady-state equilibrium between diffusive loss through the cap rock and continuous replenishment from the source rock. 15 figures, 2 tables.

Leythaeuser, D.; Schaefer, R.G.; Yukler, A.

1982-04-01

4

Migration of mineral hydrocarbons into foods. 5. Miscellaneous applications of mineral hydrocarbons in food contact materials.  

Science.gov (United States)

Polystyrene and acrylonitrile/butadiene/styrenes (ABS) containers for individual serving portions (80 samples of milk, cream, butter, margarine and spreads) used in the catering industry were found to contain 1-4% mineral oil. Levels of mineral oil migrating into the foods were generally low (corks (105 samples from 11 different countries) indicated that 50% had been treated with mineral wax or mineral oil, although in all cases mineral hydrocarbon contamination of the wine was < 0.2 mg/l. Waxed paper discs sold for home-use for covering the surface of jams and preserves were found to be coated with 100 mg/dm2 of mineral hydrocarbons. However, in experiments with a variety of jams and preserves levels of migration were not significant, ranging from 0.15 to 1.2 mg/kg. PMID:7926167

Jickells, S M; Nichol, J; Castle, L

1994-01-01

5

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...

6

From places to flows. International secondary migration and birth outcomes.  

Science.gov (United States)

Research on the health status of international migrants to industrialised countries in general, and on perinatal outcomes in particular, has assumed an interpretative model based on primary migration, characterised by one permanent cross-border movement from the migrant's country of birth. However, many migrants experience more complex migration patterns that may also be associated with human health. Secondary migration, defined as a migration from a country of residence other than the country where the immigrant was born, has been growing during the last two decades, favoured by globalisation. The purpose of this study was to examine the association between secondary migration and preterm birth (PTB) and infant birthweight at term (BW) using a Canadian official immigration database to build a cohort of immigrants to Ontario, Canada, who obtained their permanent residence in the years 1985-2000. The study population comprised 320,398 singleton live infants born to immigrant women during 1988-2007. Primary and secondary migrants were categorised according to whether they were born in an industrialised country or not. Secondary migrants were further subdivided according to whether the country from which they migrated to Canada was industrialised or not. We found that compared to primary migrants, secondary migrants to Canada born in non-industrialised countries had lower odds of PTB and higher mean BW at term. However, such a protective effect was not observed among secondary migrants born in industrialised countries. In a cross-classified multilevel model restricted to secondary migrants, 5.2% of the variation in birthweight was explained by migrants' countries of birth and 0.8% by migrants' countries of last permanent residence. These findings are consistent with the so-called healthy migrant effect, implying that selective migration from non-industrialised countries is associated with protective individual characteristics. PMID:20850920

Urquia, Marcelo L; Frank, John W; Glazier, Richard H

2010-11-01

7

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

8

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)

2000-01-01

9

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

10

Calibrating fault seal using a hydrocarbon migration model of the Oseberg Syd area, Viking Graben  

Digital Repository Infrastructure Vision for European Research (DRIVER)

It is widely acknowledged that fault rock capillary properties are important in controlling the distribution of hydrocarbons in sedimentary basins, and methods exist for predicting the capillary seal capacity of prospect bounding faults. However, fault seal capacity is rarely incorporated into models of hydrocarbon migration. This paper presents the results of migration modelling of the Oseberg Syd area of the Viking Graben incorporating fault rock capillary properties. Seal capacity is calcu...

Childs, Conrad; Sylta, Oyvind; Moriya, S.; Morewood, Nigel; Manzocchi, Tom; Walsh, John J.; Hermanssen, D.

2009-01-01

11

Primary migration by diffusion through kerogen: II. Hydrocarbon diffusivities in kerogen  

Energy Technology Data Exchange (ETDEWEB)

Laboratory experiments were performed to assess diffusion through kerogen as a mechanism of liquid hydrocarbon transport through fine-grained rocks. Such transport can be important in primary migration within source rocks and in leakage through seals. Previous work with organic-coated model cores has shown that hydrocarbon diffusion through organic matter networks can be substantially greater than hydrocarbon diffusion through aqueous pore space. In the present work, natural kerogen networks were evaluated. Experiments with five natural source rocks showed that kerogen increased the experimental hydrocarbon flux over the calculated hydrocarbon flux through pore water in only one of these source rocks, the richest (2.2% TOC) carbonate sample. Effective diffusivities through kerogen were calculated for the two experimental hydrocarbons through this sample. The results were extended with the Wilke-Chang correlation to yield diffusivities of several other hydrocarbons through similar source rocks.

Thomas, M.M.; Clouse, J.A. (Exxon Production Research Co., Houston, TX (USA))

1990-10-01

12

Modeling free product migration and recovery at hydrocarbon spill sites  

Energy Technology Data Exchange (ETDEWEB)

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.

Parker, J.C.; Zhu, J.L.; Johnson, T.G. (Environmental Systems and Technologies, Inc., Blacksburg, VA (United States)); Kremesec, V.J.; Hockman, E.L

13

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

1994-01-01

14

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

15

Regional migration of hydrocarbons as a factor in the formation of large petroleum and gas accumulation zones  

Energy Technology Data Exchange (ETDEWEB)

An examination is made of the possible variably controlled migration of hydrocarbons in such well known petroleum-gas bearing regions as the Sirt in Libya, the Mexican trough, and the Kamsk-Kinel system of depressions. Cross-sectional and diagramatic maps of the regions under study are presented. Correlations between hydrocarbon accumulation zones and trough development and organically enriched pelitomorphic sediments are demonstrated, and the role played by abnormally high stratal pressure in fluid migration is discussed. 7 references, 3 diagrams.

Shardanov, A.N.; Shumilova, M.B.

1982-01-01

16

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

17

An evaluation of hydrocarbon migration in the Birdbear Formation of southeastern Saskatchewan  

Energy Technology Data Exchange (ETDEWEB)

Hydrocarbon migration within the Upper Devonian Birdbear Formation of southeastern Saskatchewan has been evaluated using fluorescence microspectrometry of hydrocarbon fluid inclusions and of isolated, entrapped oil globules in inter-and intracrystalline pores. Much of the strata of the Birdbear Formation is variably dolomitized and holds good potential to be a carrier bed and/or reservoir. In this study, the formation is subdivided into five lithofacies units which correspond to a typical Birdbear depositional cycle. Regional stratigraphic cross-sections of the formation incorporating these five units are presented. More than 90 core and cutting samples were chosen from potential carrier bed, reservoir and seal facies of the Birdbear Formation at 36 locations. Three types of oil inclusions were defined from the suite of samples. The oils occur mainly within dolomite and calcite overgrowths, intercrystalline cements and fracture-filled anhydrites. 20 refs., 1 tab., 8 figs.

Stasiuk, L.D.; Addison, G. [Geological Survey of Canada, Calgary, AB (Canada); Steedman, R.

1998-12-01

18

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

19

Migration kinetics of mineral oil hydrocarbons from recycled paperboard to dry food: monitoring of two real cases.  

Science.gov (United States)

Mineral oil hydrocarbons present in printing inks and recycled paper migrate from paper-based food packaging to foods primarily through the gas phase. Migration from two commercial products packed in recycled paperboard, i.e. muesli and egg pasta, was monitored up to the end of their shelf life (1 year) to study the influence of time, storage conditions, food packaging structure and temperature. Mineral oil saturated and aromatic hydrocarbons (MOSH and MOAH, respectively), and diisopropyl naphthalenes (DIPN) were monitored using online HPLC-GC/FID. Storage conditions were: free standing, shelved, and packed in transport boxes of corrugated board, to represent domestic, supermarket and warehouse storage, respectively. Migration to food whose packs were kept in transport boxes was the highest, especially after prolonged storage, followed by shelved and free-standing packs. Tested temperatures were representative of refrigeration, room temperature, storage in summer months and accelerated migration testing. Migration was strongly influenced by temperature: for egg pasta directly packed in paperboard, around 30 mg kg?¹ of MOSH migrated in 8 months at 20°C, but in only 1 week at 40°C. Muesli was contained into an internal polyethylene bag, which firstly adsorbed hydrocarbons and later released them partly towards the food. Differently, the external polypropylene bag, containing pasta and recycled paper tray, strongly limited the migration towards the atmosphere and gave rise to the highest level of food contamination. Tests at increased temperatures not only accelerated migration, but also widened the migration of hydrocarbons to higher molecular masses, highlighting thus a difficult interpretation of data from accelerated simulation. PMID:23406500

Lorenzini, R; Biedermann, M; Grob, K; Garbini, D; Barbanera, M; Braschi, I

2013-01-01

20

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

Directory of Open Access Journals (Sweden)

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

Jovi? Branislav

2012-01-01

 
 
 
 
21

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

22

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.)

1986-10-05

23

Thermal evolution of organic matter and secondary hydrocarbon generation from Upper Paleozoic coal deposits in Northern China  

Energy Technology Data Exchange (ETDEWEB)

The metamorphism and hydrocarbon generation from the Upper Paleozoic coal-bearing strata in Northern China have been widely studied by Chinese geologists since the 1990s. Based on a large amount of data of Ro values, combined with geological background, we have systematically analyzed the thermal evolutionary characteristics of organic matter and the stages of hydrocarbon generation from the Permo-Carboniferous coal deposits and discussed the condition of secondary hydrocarbon generation. The distribution range of secondary hydrocarbon generation in Northern China is thus determined. It is shown that the coal ranks of the Upper Paleozoic coal deposits are higher in the southern and western belts than those in the northern and eastern belts. Really significant secondary hydrocarbon generation is mainly related to the thermal evolution of organic matter during the Himalayan Period. Profitable areas for secondary hydrocarbon generation should be buried at 3000-4000 m up to the present. Maturity of the Permo-Carboniferous source rocks is not very high. It is suggested that the Bohai Bay depression is favourable for secondary hydrocarbon generation and has good oil and gas prospects. 34 refs., 5 figs., 3 tabs.

Li-quan Zheng; Xian-qing Li; Xia Lu; Ning-ning Zhong; Xiao-yan Huang; Qiang Zhou [China University of Mining & Technology, Beijing (China). State Key Laboratory of Coal Resources and Safe Mining

2007-09-15

24

Geopressure evolution, hydrocarbon generation and migration in the Beaufort-Mackenzie Basin, Canada: results from two-dimensional quantitative modelling  

Energy Technology Data Exchange (ETDEWEB)

Three cross-sections of onshore and offshore areas of the Beaufort-MacKenzie Basin were used to simulate geopressure evolution, hydrocarbon generation and migration processes of the Tertiary section using a two-dimensional model. The model results indicate that the present day distributions of geopressure and maturity levels at different locations have been modified by late Miocene uplift and erosion, followed by rapid deposition of the late Miocene-Pleistocene lperk sediments. Although the occurrence of oil and gas has no obvious relationship to geopressure at the present day, the evolution of geopressure in strata older than the Mackenzie sequence plays an important part in the maturation of Tertiary source rocks. Geopressure in these older formations caused an increase in thermal gradient and porosity in the deep formations. The analysis indicates that the timing of hydrocarbon generation and the evolution of geopressure are critical factors in the development of horizontal migration (Reindeer reservoirs) versus vertical migration (Kugmallit reservoirs). (Author)

Jie Tang; Lerche, I. (South Carolina Univ., Columbia, SC (United States). Dept. of Geological Sciences)

1993-08-01

25

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 kinetics of hydroca...

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

2013-01-01

26

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

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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

27

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

Directory of Open Access Journals (Sweden)

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

Tissot B. P.

2006-11-01

28

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

29

Enhancement of Secondary Hydrocarbon Ion Emission Yield from Graphite Irradiated with Energetic Carbon Cluster Ion Beams  

Science.gov (United States)

When radiations, such as UV lights, X-rays, gamma-rays, and energetic electrons and ions, irradiate interstellar grains, excitation and ionization of the atoms and molecules around the surface of the grains occur, and chemical reactions are induced. Thus many kinds of organic and inorganic molecules are produced on the interstellar grains. We have observed the yield enhancement of secondary hydrocarbon cluster ion emission from graphite irradiated by energetic cluster ions. As energetic cluster ions can bombard a very small (atomic size) area of a solid surface with many atoms simultaneously and release large kinetic energy in a very short time (from femto-to pico-second region), nonlinear effects or synergetic effects are caused. This effect enhances the secondary ion emission yields. Energetic cluster ion beams used for the study of secondary ion emission processes were pro-duced by the TIARA tandem accelerator at Takasaki Advanced Radiation Research Institute, JAEA. A time of flight (TOF) mass spectrometer combined with a pulsed cluster ion beam was used for a secondary ion measurement. In this report we present some results of positive and negative secondary ion emission from a highly oriented pyrolytic graphite (HOPG) target bombarded with 0.5 MeV/atom (˜ 42 keV/amu) C1+ ˜ C8+ ions. The total secondary ion yields except for yields of hydrogen ions (H+, H2+, H3+ or H-) from a HOPG target bombarded with carbon cluster ions are presented. The yields of negative secondary ions for all incident cluster ions Cn+ are about twice of positive ion yields and the super-linear relation can be seen. We will discuss about this enhancement of the yield of secondary emission.

Shibata, Hiromi; Saitoh, Yuichi; Chiba, Atsuya; Narumi, Kazumasa

30

The use of migration barriers to prevent the spread of petroleum hydrocarbons  

International Nuclear Information System (INIS)

Contaminant containment at a remediation site can be achieved in several ways, depending upon the geochemical characteristics of the site, the nature and intensity of the contamination, and the phase distribution of the contaminants. In sites involving a contamination solute plume in groundwater, the containment issue has classically been achieved with some form of hydraulic extraction system, where elevation gradients have been achieved by pumps in vertical (or horizontal) wells. Plumes of solute contaminants in the aquifer have been captured by closure of the flow lines at the extraction well(s) location and the extracted water transported to a treatment system for removal of the dissolved contaminant species. While frequently referred to as ''pump and treat,'' such systems are not true treatment concepts and usually fail to address the ''source'' which exists upgradient in the form of oily-phase ''free'' adsorbed or entrained phases in the aquifer material itself. The use of air sparging techniques to effect both physical removal and biological degradation and the use of a row of wells containing a slow release oxygen compound are discussed as methods of mitigating migration of monoaromatic hydrocarbons (BTEX) and other volatile and/or aerobically biodegradable contaminants

1995-06-14

31

Large-Scale Multiphase Flow Modeling of Hydrocarbon Migration and Fluid Sequestration in Faulted Cenozoic Sedimentary Basins, Southern California  

Science.gov (United States)

Major fault systems play a first-order role in controlling fluid migration in the Earth's crust, and also in the genesis/preservation of hydrocarbon reservoirs in young sedimentary basins undergoing deformation, and therefore understanding the geohydrology of faults is essential for the successful exploration of energy resources. For actively deforming systems like the Santa Barbara Basin and Los Angeles Basin, we have found it useful to develop computational geohydrologic models to study the various coupled and nonlinear processes affecting multiphase fluid migration, including relative permeability, anisotropy, heterogeneity, capillarity, pore pressure, and phase saturation that affect hydrocarbon mobility within fault systems and to search the possible hydrogeologic conditions that enable the natural sequestration of prolific hydrocarbon reservoirs in these young basins. Subsurface geology, reservoir data (fluid pressure-temperature-chemistry), structural reconstructions, and seismic profiles provide important constraints for model geometry and parameter testing, and provide critical insight on how large-scale faults and aquifer networks influence the distribution and the hydrodynamics of liquid and gas-phase hydrocarbon migration. For example, pore pressure changes at a methane seepage site on the seafloor have been carefully analyzed to estimate large-scale fault permeability, which helps to constrain basin-scale natural gas migration models for the Santa Barbara Basin. We have developed our own 2-D multiphase finite element/finite IMPES numerical model, and successfully modeled hydrocarbon gas/liquid movement for intensely faulted and heterogeneous basin profiles of the Los Angeles Basin. Our simulations suggest that hydrocarbon reservoirs that are today aligned with the Newport-Inglewood Fault Zone were formed by massive hydrocarbon flows from deeply buried source beds in the central synclinal region during post-Miocene time. Fault permeability, capillarity forces between the fault and juxtaposition of aquifers/aquitards, source oil saturation, and rate of generation control the efficiency of a petroleum trap and carbon sequestration. This research is focused on natural processes in real geologic systems, but our results will also contribute to an understanding of the subsurface behavior of injected anthropogenic greenhouse gases, especially when targeted storage sites may be influenced by regional faults, which are ubiquitous in the Earth's crust.

Jung, B.; Garven, G.; Boles, J. R.

2011-12-01

32

Hydrocarbons  

Energy Technology Data Exchange (ETDEWEB)

This volume represents the most comprehensive, unified volume to data on the gas chromatography of hydrocarbons. It covers the world's literature between 1970 to 1980 and addresses the wide diversity of hydrocarbon structures, the basic operating components of the gas chromatographic system and their control for optimizing separations. Numerous chromatograms depicting separations of various hydrocarbon classes are included. It features three major sections on hydrocarbon analysis with respect to: general applications, specific studies, special techniques. This volume describes the properties and characteristics of and studies employing the broad spectrum of available liquid phases and adsorbents as separating media, and studies reporting retention data for the different hydrocarbon classes. It includes 45 comprehensive retention tables containing several thousand indices in a standardized retention index format.

Zielinski, W.L. Jr.

1987-01-01

33

Secondary migration - visualizing the invisible - what can geochemistry potentially d{sup 0}  

Energy Technology Data Exchange (ETDEWEB)

Lateral petroleum secondary migration takes place rapidly on geological time scales (km Ma{sup -1} or greater) over ranges of up to several hundreds of kilometres in permeable (> 1mD) carrier beds. The distribution of petroleum within carrier beds is controlled by petroleum buoyancy, hydrodynamics and capillary forces, and both theoretical and field studies of oil migration suggest that, in general, oil is transmitted through relatively small portions of carrier systems. The dimensions and residual oil saturations of actual carrier systems are difficult (if not impossible) to examine directly, but geochemical tracers within reservoired oil may provide us with important clues. We present in this paper a schematic illustration of how such technology may develop and suggest that large oil fields may fill through very small net carrier volumes. (author)

Larter, S.; Taylor, P.; Mei Chen; Bowler, B. [University of Newcastle (United Kingdom). Fossil Fuels and Environmental Geochemistry; Ringrose, P. [Heriot-Watt University, Edinburgh (United Kingdom). Dept. of Petroleum Engineering; Horstad, I. [Saga Petroleum a.s., Sandvika (Norway)

1996-12-31

34

A study of the migration and accumulation efficiency and the genesis of hydrocarbon natural gas in the Xujiaweizi fault depression  

Energy Technology Data Exchange (ETDEWEB)

In order to investigate the migration and accumulation efficiency of hydrocarbon natural gas in the Xujiaweizi fault depression, and to provide new evidence for the classification of its genesis, a source rock pyrolysis experiment in a closed system was designed and carried out. Based on this, kinetic models for describing gas generation from organic matter and carbon isotope fractionation during this process were established, calibrated and then extrapolated to geologic conditions by combining the thermal history data of the Xushen-1 Well. The results indicate that the coal measures in the Xujiaweizi fault depression are typical 'high-efficiency gas sources', the natural gas generated from them has a high migration and accumulation efficiency, and consequently a large-scale natural gas accumulation occurred in the area. The highly/over matured coal measures in the Xujiaweizi fault depression generate coaliferous gas with a high {delta}{sup 13}C{sub 1} value ( > -20 parts per thousand) at the late stage, making the carbon isotope composition of organic alkane gases abnormally heavy. In addition, the mixing and dissipation through the caprock of natural gas can result in the negative carbon isotope sequence {delta} {sup 13}C{sub 1} > {delta}{sup 13}C{sub 2} > {delta}{sup 13}C{sub 4} of organic alkane gases, and the dissipation can also lead to the abnormally heavy carbon isotope composition of organic alkane gases. As for the discovery of inorganic nonhydrocarbon gas reservoirs, it can only serve as an accessorial evidence rather than a direct evidence that the hydrocarbon gas is inorganic. As a result, it needs stronger evidence to classify the hydrocarbon natural gas in the Xujiaweizi fault depression as inorganic gas.

Li, J.J.; Lu, S.F.; Xue, H.T.; Huo, Q.L.; Xu, Q.X. [Daqing Petrology Institute, Daqing (China)

2008-06-15

35

Analysis of cell migration, transdifferentiation and apoptosis during mouse secondary palate fusion.  

Science.gov (United States)

Malformations in secondary palate fusion will lead to cleft palate, a common human birth defect. Palate fusion involves the formation and subsequent degeneration of the medial edge epithelial seam. The cellular mechanisms underlying seam degeneration have been a major focus in the study of palatogenesis. Three mechanisms have been proposed for seam degeneration: lateral migration of medial edge epithelial cells; epithelial-mesenchymal trans-differentiation; and apoptosis of medial edge epithelial cells. However, there is still a great deal of controversy over these proposed mechanisms. In this study, we established a [Rosa26C57BL/6] chimeric culture system, in which a Rosa26-originated ;blue' palatal shelf was paired with a C57BL/6-derived ;white' palatal shelf. Using this organ culture system, we observed the migration of medial edge epithelial cells to the nasal side, but not to the oral side. We also observed an anteroposterior migration of medial edge epithelial cells, which may play an important role in posterior palate fusion. To examine epithelial-mesenchymal transdifferentiation during palate fusion, we bred a cytokeratin 14-Cre transgenic line into the R26R background. In situ hybridization showed that the Cre transgene is expressed exclusively in the epithelium. However, beta-galactosidase staining gave extensive signals in the palatal mesenchymal region during and after palate fusion, demonstrating the occurrence of an epithelial-mesenchymal transdifferentiation mechanism during palate fusion. Finally, we showed that Apaf1 mutant mouse embryos are able to complete palate fusion without DNA fragmentation-mediated programmed cell death, indicating that this is not essential for palate fusion in vivo. PMID:16887819

Jin, Jiu-Zhen; Ding, Jixiang

2006-09-01

36

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

37

Importance of Aqueous-phase Secondary Organic Aerosol Formation from Aromatics in an Atmospheric Hydrocarbon Mixture  

Science.gov (United States)

Two new secondary organic aerosol (SOA) modeling frameworks are developed, one based on an aromatic gas and particle-phase kinetic mechanism and another based on a parameterized SOA model used in conjunction with an underlying gas-phase mechanism, both of which simulate SOA formation through partitioning to two stable liquid phases: one hydrophilic containing particle aqueous-phase and the other hydrophobic comprising mainly organic components. The models were evaluated against outdoor smog chamber experiments with different combinations of initial toluene, o-xylene, p-xylene, toluene and xylene mixtures, NOx, non-SOA-forming hydrocarbon mixture, initial seed type, and humidity. Aerosol data for experiments with either ammonium sulfate or initial background seed particles, in the presence of an atmospheric hydrocarbon mixture, NOx and in sunlight under a dry atmosphere (RH = 6 to 10%) show reduced SOA formation when compared to experiments with similar initial gas and particle concentrations at higher relative humidities (RH = 40 to 90%). Both frameworks simulated reasonable fits to the total observed SOA concentrations under all conditions. For both dry and wet experiments with low initial seed, semi-volatile product partitioning in particle organic-phase is mass-transfer limited and is modeled using a dynamic gas-particle partitioning algorithm with accommodation coefficient as the primary pseudo-transport parameter. Further, the modeled SOA product distributions for both frameworks clearly show the importance of the contribution of aqueous-phase SOA particularly under conditions of low initial seed concentrations and high-humidity. For both models, under these conditions, aqueous-phase SOA from uptake of glyoxal, methylglyoxal and related polar products to particle water phase dominates as compared to the partitioning of semi-volatiles to particle organic phase. Interestingly, both the kinetic and parameterized SOA frameworks simulate similar amounts of aqueous-phase SOA for each experiment. For wet experiments with initial ammonium sulfate seed, the modeled fraction of aqueous-phase SOA is up to 82% of the total ammonium sulfate mass and for wet experiment with initial background seed this fraction is as high as 60% of the total particle mass formed for the duration of the experiments. This suggests that aqueous-phase SOA from oxidation of toluene and xylene, under atmospherically relevant conditions, is significant and should be part of kinetic or parameterized SOA modeling frameworks in current air quality models.

Parikh, H. M.; Carlton, A. G.; Vizuete, W.; Zhang, H.; Zhou, Y.; Chen, E.; Kamens, R. M.

2010-12-01

38

Migration.  

Science.gov (United States)

The note explains the different definitions of immigration, emigration, and net migration, and how they all differ from each other. It shows patterns of population change since 1970, the reasons for this change, and how they arrived at the figures they go...

C. A. Young

1977-01-01

39

Estimates of the contributions of biogenic and anthropogenic hydrocarbons to secondary organic aerosol at a southeastern US location  

Science.gov (United States)

An organic tracer-based method containing laboratory and field study components was used to estimate the secondary organic aerosol (SOA) contributions of biogenic and anthropogenic hydrocarbons to ambient organic carbon (OC) concentrations in PM 2.5 during 2003 in Research Triangle Park, NC. In the laboratory, smog chamber experiments were conducted where isoprene, ?-pinene, ?-caryophyllene, and toluene were individually irradiated in the presence of NO X. In each experiment, SOA was collected and analyzed for potential tracer compounds, whose concentrations were used to calculate a mass fraction of tracer compounds for each hydrocarbon. In the field, 33 PM 2.5 samples were collected and analyzed for (1) tracer compounds observed in the laboratory irradiations, (2) levoglucosan, a biomass burning tracer, and (3) total OC. For each of the four hydrocarbons, the SOA contributions to ambient OC concentrations were estimated using the tracer concentrations and the laboratory-derived mass fractions. The estimates show SOA formation from isoprene, ?-pinene, ?-caryophyllene, and toluene contributed significantly to the ambient OC concentrations. The relative contributions were highly seasonal with biomass burning in the winter accounting for more than 50% of the OC concentrations, while SOA contributions remained low. However, during the 6-month period between May and October, SOA from the precursor hydrocarbons contributed more than 40% of the measured OC concentration. Although the tracer-based method is subject to considerable uncertainty due to the simplification of replacing the complex set of chemical reactions responsible for SOA with a laboratory-derived single-valued mass fraction, the results suggest this approach can be used to identify major sources of SOA which can assist in the development of air quality models.

Kleindienst, Tadeusz E.; Jaoui, Mohammed; Lewandowski, Michael; Offenberg, John H.; Lewis, Charles W.; Bhave, Prakash V.; Edney, Edward O.

40

Migrated hydrocarbons in exposure of Maastrichtian nonmarine strata near Saddle Mountain, lower Cook Inlet, Alaska  

Science.gov (United States)

Magoon and others (1980) described an 83-meter- (272-foot-) thick succession of Maastrichtian (Upper Cretaceous) conglomerate, sandstone, mudstone, and coal exposed on the south side of an unnamed drainage, approximately 3 kilometers (1.8 miles) east of Saddle Mountain in lower Cook Inlet (?gs. 1 and 2). The initial signi?cance of this exposure was that it was the ?rst reported occurrence of nonmarine rocks of this age in outcrop in lower Cook Inlet, which helped constrain the Late Cretaceous paleogeography of the area and provided important information on the composition of latest Mesozoic sandstones in the basin. The Saddle Mountain section is thought to be an outcrop analog for Upper Cretaceous nonmarine strata penetrated in the OCS Y-0097 #1 (Raven) well, located approximately 40 kilometers (25 miles) to the south–southeast in Federal waters (?g. 1). Atlantic Rich?eld Company (ARCO) drilled the Raven well in 1980 and encountered oil-stained rocks and moveable liquid hydrocarbons between the depths of 1,760 and 3,700 feet. Completion reports on ?le with the Bureau of Ocean Energy Management (BOEM; formerly Bureau of Ocean Energy Management, Regulation and Enforcement, and prior to 2010, U.S. Minerals Management Service) either show ?ow rates of zero or do not mention ?ow rates. A ?uid analysis report on ?le with BOEM suggests that a wireline tool sampled some oil beneath a 2,010-foot diesel cushion during the ? ow test of the 3,145–3,175 foot interval, but the recorded ? ow rate was still zero (Kirk Sherwood, written commun., January 9, 2012). Further delineation and evaluation of the apparent accumulation was never performed and the well was plugged and abandoned. As part of a 5-year comprehensive evaluation of the geology and petroleum systems of the Cook Inlet forearc basin, the Alaska Division of Geological & Geophysical Surveys obtained a research permit from the National Park Service to access the relatively poorly understood ‘Saddle Mountain exposure’ that is located in the Lake Clark National Park and Preserve. This work was done in cooperation with the Alaska Division of Oil & Gas and U.S. Geological Survey (USGS) research geologists. This report expands on Magoon and others’ (1980) description of the exposure, presents new data on sandstone composition and reservoir quality, presents new geochemical data on petroleum extracted from the outcropping sandstone, and describes oil-bearing correlative strata penetrated by the Raven well. Although the exposure is more than a kilometer (0.6 mile) east of Saddle Mountain (?g. 2), in this report we variously refer to it as the Saddle Mountain succession, Saddle Mountain section, or the rocks at Saddle Mountain underlain by Upper Jurassic strata of the Naknek Formation.

LePain, D. L.; Lillis P. G.; Helmold, K. P.; Stanley, R. G.

2012-01-01

 
 
 
 
41

A case of lower lid ulcer secondary to reverse migration of silicone punctal plug.  

Science.gov (United States)

Silicone punctal plugs are effective and relatively safe method of managing keratoconjunctivitis sicca. We present a case where a silicone punctal plug migrated to cause aseptic necrosis of the surrounding tissue leading to a lid ulcer. PMID:18836936

Mukherji, S; Aralikatti, A; Sandramouli, S; Ilango, B

2008-01-01

42

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

43

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

44

Migration of polycyclic aromatic hydrocarbons (PAHs) in urban treatment sludge to the air during PAH removal applications.  

Science.gov (United States)

In the present study, the amounts of polycylic aromatic hydrocarbons (PAHs) penetrating into air during PAH removal applications from the urban treatment sludge were investigated. The effects of the temperature, photocatalyst type, and dose on the PAH removal efficiencies and PAH evaporation were explained. The sludge samples were taken from an urban wastewater treatment plant located in the city of Bursa, with 585,000 equivalent population. The ultraviolet C (UV-C) light of 254 nm wavelength was used within the UV applications performed on a specially designed setup. Internal air of the setup was vacuumed through polyurethane foam (PUF) columns in order to collect the evaporated PAHs from the sludge during the PAH removal applications. All experiments were performed with three repetitions. The PAH concentrations were measured by gas chromatography-mass spectrometry (GC-MS). It was observed that the amounts of PAHs penetrating into the air were increased with increase of temperature, and more than 80% of PAHs migrated to the air consisted of 3-ring compounds during the UV and UV-diethylamine (DEA) experiments at 38 and 53 degrees C. It was determined that 40% decrease was ensured in sigma12 (total of 12) PAH amounts with UV application and 13% of PAHs in sludge penetrated into the air. In the UV-TiO2 applications, a maximum 80% of sigma12 PAH removal was obtained by adding 0.5% TiO2 of dry weight of sludge. The quantity of PAH penetrating into air did not exceed 15%. UV-TiO2 applications ensured high levels of PAH removal in the sludge and also reduced the quantity of PAH penetrating into the air. Within the scope of the samples added with DEA, there was no increase in PAH removal efficiencies and the penetration of PAHs into air was not decreased. In light of these data, it was concluded that UV-TiO2 application is the most suitable PAH removal alternative that restricts the convection of PAH pollution. PMID:24941705

Karaca, Gizem; Cindoruk, S Siddik; Tasdemir, Yücel

2014-05-01

45

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.

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

2014-05-01

46

Fluorescence micro-spectrometry of synthetic and natural hydrocarbon fluid inclusions: crude oil chemistry, density and application to petroleum migration  

Energy Technology Data Exchange (ETDEWEB)

The fluorescence spectra of crude oils, synthesized as hydrocarbon fluid inclusions (hcfi) in NaCl crystals, have been recorded and correlated with crude oil chemical analysis. The crude oils represent a wide range in total hydrocarbons, saturate and aromatic fractions, and resin-asphaltene concentration. The fluorescence properties (Lambda max and Q) of the hydrocarbon fluid inclusions display a systematic red shift to longer wavelengths from 440 nm to 595 nm with increasing aromatic content and increasing concentration of NSO-bearing compounds. A positive correlation also exists between Lmax-Q and the thermal maturity parameters nC{sub 17}/pristane and nC{sub 18}/phytane. First order linear regression equations provide a method for constraining the chemical composition of natural hydrocarbon fluid inclusions. Lmax and Q correlate positively with oil density ({sup o}API), providing for an indirect method of estimating the API of a natural hydrocarbon fluid inclusion assemblage. Fluorescence spectra of non-biodegraded crude oils from the Upper Devonian Birdbear Formation, Saskatchewan, Canada, have been correlated with regionally widespread hcfi within carbonate carrier beds and reservoir rocks of the same formation. Spectra from hcfi within quartz overgrowths and cements, fractures and carbonate cements from sandstone reservoirs in the Jeanne d`Arc Basin offshore Newfoundland, compared with fluorescence spectra of crude oils suggests that some of the reservoirs may have been filled by a relatively low maturity oil and then a higher maturity oil. (author)

Stasiuk, L.D.; Snowdon, L.R. [Geological Survey of Canada, Calgary, AB (Canada)

1997-05-01

47

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

48

Post-hydrocarbon migration deep burial diagenesis of Smackover Formation, Black Creek field, Wiggins arch, Mississippi salt basin  

Energy Technology Data Exchange (ETDEWEB)

The Smackover Formation is buried to over 6 km in Black Creek field and exhibits diagenetic phases unique to deep burial. These include replacement of sulfates by calcite, pore-fill calcite cement, silicification, and elemental sulfur as cement. The above diagenetic products are the result of thermal reduction of sulfates and thermal degradation of hydrocarbons and have formed at temperatures greater than 140/degrees/C. Calcite replaces anhydrite in two textural forms, one of which is pseudomorphic. Pore-fill calcite cement contains inclusions of pyrobitumen and heals cracks formed in the pyrobitumen due to high thermal maturity. This indicates that calcite cement postdates bitumen formation. Silicification is a major deep burial event. Micron to millimetersize crystals of quartz replace the host carbonate rock as well as other deep burial diagenetic phases. Elemental sulfur occurs as inclusions in incompletely destroyed sulfates and as pore-fill cement. In both cases it exhibits extensive bubble-shaped cavities similar to pumiceous texture found in volcanic rocks. This indicates that elemental sulfur was possibly crystallized rapidly from a liquid sulfur while the cores were being taken. Similar diagenetic products are formed by low-temperature (< 80/degrees/C) bacterial reduction of sulfates and bacterial degradation of hydrocarbons. However, carbon isotopic composition of calcite, sulfur isotopic composition of elemental sulfur, and textural characteristics of elemental sulfur produced by the two diagenetic processes are significantly different.

Heydari, E.; Moore, C.H.

1989-03-01

49

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

50

The evolution of fluid pressures in the Alberta Basin: implications for secondary migration of petroleum through the Viking Formation  

Energy Technology Data Exchange (ETDEWEB)

A study was conducted in which the significance of different factors that controlled the distribution of petroleum in the Viking Formation of the Alberta Basin were assessed. A cross-sectional numerical model was used to reconstruct the petroleum generation, primary sourcing directions and the fluid pressures for an East-West transect across the Basin during active deposition and subsequent uplift. Heterogeneities within the Viking sandstone played a major role in the development of simulated oil migration pathways. High permeability sands in the Viking Formation permitted long-range migration, while low permeability zones trapped oil close to the mature source region.

Bekele, E.B.; Person, M. [Minnesota Univ., Duluth, MN (United States). Dept. of Geology; Rostron, B.J. [Saskatchewan Univ., Saskatoon, SK (Canada)

1997-09-01

51

Composition of secondary organic particulate matter from the photo-oxidation of hydrocarbons using APCI/MS-MS  

Science.gov (United States)

The particle phase products from the oxidation of aromatic hydrocarbons by hydroxyl radicals in the presence of NO have been analysed using an atmospheric pressure chemical ionisation triple quadrupole mass spectrometer (APCI/MS-MS). Reactions are performed in a two-litre flow cell with a residence time of around four minutes. In this cell the hydrocarbon, NO and the radical source (isopropyl nitrite), are irradiated by a 1000 W xenon arc lamp. The reaction products are in both the gas and particle phases. The gases are removed using a denuder system and some of the particulate matter is introduced in the MS ion source via an inline heater. The power to the heater can be varied to allow variable-temperature evaporation of the particulate matter into the ion source. The focus so far has been on the HO oxidation of toluene and meta-xylene. A number of possible product molecules were identified; their MS-MS fingerprint established and compared with the observed reaction products. Some twenty individual compounds ranging from aromatic aldehydes to quinones and furanones have been identified in this way. A number of additional compounds have yet to be unambiguously identified.

Zarna, A.; Graham, J.; Collin, F.; Hastie, D.

2003-04-01

52

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 ...

53

[Biological monitoring of exposure to carcinogenic metallic elements and polycyclic aromatic hydrocarbons in four secondary metallurgical sectors].  

Science.gov (United States)

This cross-sectional study was aimed at evaluating in a large sample of male foundry workers the current exposure levels to carcinogenic compounds, including metallic elements [arsenic (As), beryllium (Be), cadmium (Cd), chromium (Cr), nickel (Ni)] and aromatic polycyclic hydrocarbons (PAH) by a biological monitoring approach, using validated biomarkers of exposure. Workers were recruited from 15 aluminium, copper alloy, electric steel and cast iron foundries and provided an end-of-shift urine sample to determine urinary concentrations of As, Be, Cd, Cr, Ni and 1-hydroxypyrene (1-OHP). Metallic elements were determined either by inductively coupled plasma mass spectrometry (Be, Cd and Cr) or by atomic absorption spectrometry (As, Ni), whereas 1-OHP was determined by high pressure liquid chromatography with fluorimetric detection. Most of the determinations fell within the laboratory's reference values. Age and lifestyle habits (smoking, alcohol, diet) played a significant interfering role. PMID:23405579

De Palma, G; Corsini, A; Gilberti, E; Gabusi, V; Tagliani, G; Tomasi, C; Gandellini, A; Apostoli, P

2012-01-01

54

Investigation of the utility of laser-secondary neutral mass spectrometry for the detection of polyaromatic hydrocarbons in individual atmospheric aerosol particles.  

Science.gov (United States)

The distribution of polyaromatic hydrocarbons (PAHs) in ambient aerosol particles is of importance to both human health and climate forcing. Although time-of-flight secondary ion mass spectrometry (ToF-SIMS) has proven useful for studying the distribution of organic compounds in individual aerosol particles, it is difficult to detect PAHs at relevant concentrations in individual aerosol particles because of their low ion yield. In this study, we explore the potential of using laser secondary neutral mass spectrometry (Laser-SNMS) to study three PAHs: pyrene, anthracene, and naphthalene. Because of the high volatility of PAHs, a cryostage was required for the analysis to prevent sublimation of the molecules into the vacuum chamber. We studied two laser systems, a 157 nm excimer laser, which is capable of single-photon ionization of the PAHs, and a 193 nm laser, which requires multiphoton ionization. Under optimized conditions for laser power density and primary ion pulse length, 193 nm postionization resulted in a 2-50-fold increase in ion yield over ToF-SIMS. Using the 157 nm laser, the yield was increased by more than 3 orders of magnitude for all 3 PAHs studied. The single-photon postionization process proved superior in terms of both yield enhancement and reduced fragmentation. By using the optimized 157 nm laser system and a cryostage, we were able to detect PAHs on the surface of 2 ?m diameter ambient aerosol particles. PMID:21823569

Tyler, Bonnie J; Dambach, Steffen; Galla, Sebastian; Peterson, Richard E; Arlinghaus, Heinrich F

2012-01-01

55

CCR7 Guides Migration of Mesenchymal Stem Cell to Secondary Lymphoid Organs: A Novel Approach to Separate GvHD from GvL Effect.  

Science.gov (United States)

Inefficient homing of systemically infused mesenchymal stem cells (MSCs) limits the efficacy of existing MSC-based clinical graft-versus-host disease (GvHD) therapies. Secondary lymphoid organs (SLOs) are the major niches for generating immune responses or tolerance. MSCs home to a wide range of organs, but rarely to SLOs after intravenous infusion. Thus, we hypothesized that targeted migration of MSCs into SLOs may significantly improve their immunomodulatory effect. Here, chemokine receptor 7 (CCR7) gene, encoding a receptor that specifically guides migration of immune cells into SLOs, was engineered into a murine MSC line C3H10T1/2 by retrovirus transfection system (MSCs/CCR7). We found that infusion of MSCs/CCR7 potently prolonged the survival of GvHD mouse model. The infused MSCs/CCR7 migrate to SLOs, relocate in proximity with T lymphocytes, therefore, potently inhibited their proliferation, activation, and cytotoxicity. Natural killer (NK) cells contribute to the early control of leukemia relapse. Although MSCs/CCR7 inhibited NK cell activity in vitro coculture, they did not impact on the proportion and cytotoxic capacities of NK cells in the peripheral blood of GvHD mice. In an EL4 leukemia cell loaded GvHD model, MSCs/CCR7 infusion preserved the graft-versus-leukemia (GvL) effect. In conclusion, this study demonstrates that CCR7 guides migration of MSCs to SLOs and thus highly intensify their in vivo immunomodulatory effect while preserving the GvL activity. This exciting therapeutic strategy may improve the clinical efficacy of MSC based therapy for immune diseases. Stem Cells 2014;32:1890-1903. PMID:24496849

Li, Hong; Jiang, YanMing; Jiang, XiaoXia; Guo, XiMin; Ning, HongMei; Li, YuHang; Liao, Li; Yao, HuiYu; Wang, XiaoYan; Liu, YuanLin; Zhang, Yi; Chen, Hu; Mao, Ning

2014-07-01

56

Fault-fracture mesh petroleum plays in the Zhanhua Depression, Bohai Bay Basin: Part 2: Oil-source correlation and secondary migration mechanisms  

Energy Technology Data Exchange (ETDEWEB)

The chemical compositions of crude oils from over 20 oilfields in the Zhanhua Depression, Bohai Bay Basin, were studied in order to understand their genetic relationships, thermal maturity and biodegradation ranking. Molecular geochemical parameters indicate the presence of three possible oil families in reservoirs ranging from Paleozoic (basement) to Neogene. A number of biomarker features support deposition of the source rocks for these oils under a wide range of depositional environments. The majority of the oils discovered in the depression belong to the FL family, and display characteristics consistent with a dominantly freshwater (to slightly brackish water) lacustrine source rock in the Es{sub 3} member of the Shahejie Formation. The somewhat geographically restricted SL family oils are apparently linked to saline lacustrine, carbonate-evaporite source rocks distributed mostly in the upper Es{sub 4} member of the Shahejie Formation from the Bonan-Gubei sag areas. The thermally less mature BL family oils occur mostly within the Es{sub 1}, Es{sub 2} or Dongying Formation reservoirs near the central sag areas, and show close affinities to the interbedded or intercalating Es{sub 1} calcareous mudstones and oil shales deposited in a slightly saline to dominantly brackish water lacustrine setting. The SL and FL family oils are generally mature, whereas most of the BL family oils usually show low maturity. Oil-source correlation demonstrates strong genetic relationships between the mature Es{sub 4} and Es{sub 3} source rocks of the Eocene-Oligocene Shahejie formation in the sag areas and the oils accumulated in the shallow Neogene petroleum plays. The geochemical data provide strong support for two sharply contrasting hydrocarbon migration scenarios: (1) short distance lateral migration is dominant in the central sag areas; and (2) the fault-fracture mesh facilitated vertical migration, and coupled with the regional porous Guantao Formation sand sheets, makes the structural, stratigraphic and lithological features over basement high blocks the focal points for petroleum accumulation. Therefore, further exploration in this highly mature petroleum province should focus on heavy oils in the shallow Neogene strata and light oils in the tight sandstones of the deep sag areas. (Author)

Dishi Shi; Yongshi Wang [SINOPEC Shengli Oilfield Co., Shandong (China). Geoscience Research Inst.; Maowen Li; Dong Xia [Petroleum Univ., Beijing (China); Geological Survey of Canada, NW Calgary (Canada); Xiongqi Pang [Petroleum Univ., Beijing (China); Shanwen Zhang [SINOPEC Shengli Oilfield Co., Shandong (China)

2005-02-01

57

Hydrocarbon pneumonia  

Science.gov (United States)

Pneumonia - hydrocarbon ... Coughing Fever Shortness of breath Smell of a hydrocarbon product on the breath Stupor Vomiting ... Most children who drink or inhale hydrocarbon products and develop ... hydrocarbons may lead to rapid respiratory failure and death.

58

Polynuclear aromatic hydrocarbon and particulate emissions from two-stage combustion of polystyrene: the effects of the secondary furnace (afterburner) temperature and soot filtration.  

Science.gov (United States)

Laboratory experiments were conducted in a two-stage horizontal muffle furnace in order to monitor emissions from batch combustion of polystyrene (PS) and identify conditions that minimize them. PS is a dominant component of municipal and hospital waste streams. Bench-scale combustion of small samples (0.5 g) of shredded styrofoam cups was conducted in air, using an electrically heated horizontal muffle furnace, kept at Tgas = 1000 degrees C. Upon devolatilization, combustion of the polymer took place in a diffusion flame over the sample. The gaseous combustion products were mixed with additional air in a venturi and were channeled to a secondary muffle furnace (afterburner) kept at Tgas = 900-1100 degrees C; residence time therein varied between 0.6 and 0.8 s. At the exits of the primary and the secondary furnace the emissions of CO, CO2, O2, NOx, particulates as well as volatile and semivolatile hydrocarbons, such as polycyclic aromatic hydrocarbons (PAH), were monitored. Online analyzers, gravimetric techniques, and gas chromatography coupled to mass spectrometry (GC-MS) were used. Experiments were also conducted with a high-temperature barrier filter, placed just before the exit of the primary furnace to prevent the particulates from entering into the secondary furnace. Results demonstrated the beneficial effect of the afterburner in reducing PAH concentrations, including those of mutagenic species such as benzo[a]pyrene. Concentrations of individual PAH exhibited a pronounced after burner temperature dependence, typically ranging from a small decrease at 900 degrees C to a larger degree of consumption at 1100 degrees C. Consumption of PAH was observed to be the dominant feature at 900 degrees C, while significant quantities of benzene and some of its derivatives, captured by means of carbosieve/Carbotrap adsorbents, were formed in the afterburner at a temperature of 1000 degrees C. In the primary furnace, about 30% of the mass of the initial polystyrene was converted into soot, while the total mass of PAH represented about 3% of the initial mass of combustible. The afterburner reduced the particulate (soot) emissions by only 20-30%, which indicates that once soot is formed its destruction is rather difficult because its oxidation kinetics are slow undertypical furnace conditions. Moreover, increasing the afterburnertemperature resulted in an increasing trend of soot emissions therefrom, which might indicate competition between soot oxidation and formation, with some additional formation occurring at the higher temperatures. Contrary to the limited effect of the afterburner, high-temperature filtration of the combustion effluent prior to the exit of the primary furnace allowed for effective soot oxidation inside of the ceramic filter. Filtration drastically reduced soot emissions, by more than 90%. Limited soot formation in the afterburner was again observed with increasing temperatures. The yields of both CO and CO2 were largely unaffected by the temperature of the afterburner but increased at the presence of the filter indicating oxidation therein. A previously developed kinetic model was used to identify major chemical reaction pathways involving PAH in the afterburner. The experimental data at the exit of the primary furnace was used as input to these model computations. A first evaluation of the predictive capability of the model was conducted for the case with ceramic filter and a temperature of 900 degrees C. The afterburner was approximated as a plug-flow reactor, and model predictions at a residence time of 0.8 s were compared to experimental data collected at its exit. In agreement with the experimental PAH concentration, only a minor impact of the afterburner treatment was observed for most species at 900 degrees C. OH was deduced to be the major reactant with a mole fraction about 4 orders of magnitudes higher than that of hydrogen radicals. Evidence for the need of further work on the quantitative assessment of oxidation of PAH and their radicals is given. PMID:11878400

Wang, Jun; Richter, Henning; Howard, Jack B; Levendis, Yiannis A; Carlson, Joel

2002-02-15

59

AD1995: NW Europe's hydrocarbon industry  

International Nuclear Information System (INIS)

This volume concerns itself with wide-ranging aspects of the upstream hydro-carbon industry over the whole of NW Europe. As such, the book contrasts with many thematic volumes by presenting a broad range of topics side-by-side. One section of the book looks back at the history of geological exploration and production, and provides an overview of hydrocarbon exploration across NW Europe. Another section covers the state of the art in hydrocarbon exploration and production. This includes an update on computer-based basin modelling overpressure systems, innovations in reservoir engineering and reserve estimation, 3D seismic and the geochemical aspects of secondary migration. The final section of the book takes a look into the future. This covers the remaining hydrocarbon resources of the North Sea, managing risk in oil field development, oil field economics, and pollution and the environment. It is the editors' hope that several key areas of NW Europe's upstream oil industry have been usefully summarized in the volume. (Author)

1996-01-01

60

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.

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

 
 
 
 
61

Hydrocarbon extractor  

Energy Technology Data Exchange (ETDEWEB)

This patent describes a method for removing hydrocarbons from soil. It comprises placing the soil in an open container, heating the soil and the entrained hydrocarbons by directing heat against the soil; creating a sub-atmospheric pressure within the soil by establishing a vacuum beneath the soil; vaporizing the hydrocarbons within the soil; removing the vaporized hydrocarbon downwardly from the soil; withdrawing the vaporized hydrocarbon from beneath the soil; and discharging the vaporized hydrocarbons.

O' Ham, J.K.

1992-07-07

62

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

63

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

64

AD1995: NW Europe`s hydrocarbon industry  

Energy Technology Data Exchange (ETDEWEB)

This volume concerns itself with wide-ranging aspects of the upstream hydro-carbon industry over the whole of NW Europe. As such, the book contrasts with many thematic volumes by presenting a broad range of topics side-by-side. One section of the book looks back at the history of geological exploration and production, and provides an overview of hydrocarbon exploration across NW Europe. Another section covers the state of the art in hydrocarbon exploration and production. This includes an update on computer-based basin modelling overpressure systems, innovations in reservoir engineering and reserve estimation, 3D seismic and the geochemical aspects of secondary migration. The final section of the book takes a look into the future. This covers the remaining hydrocarbon resources of the North Sea, managing risk in oil field development, oil field economics, and pollution and the environment. It is the editors` hope that several key areas of NW Europe`s upstream oil industry have been usefully summarized in the volume. (Author)

Glennie, K.; Hurst, A. [eds.] [Aberdeen Univ. (United Kingdom)

1996-12-31

65

Resins and asphaltenes in the generation and migration of petroleum  

Energy Technology Data Exchange (ETDEWEB)

Petroleum is a stable colloidal sol, with a continuous transition from the smallest hydrocarbon molecules to the bulkiest micelles. Asphaltenes are the micellar fraction precipitated by n-heptane; in the remainder, resins - the non-hydrocarbon fraction - are separated by liquid chromatography. Resins control the sol stability. Hydrocarbons can be produced directly from kerogen; the relative importance of resins and asphaltenes can be different in different situations. Resins and asphaltenes are however valuable indicators of the origin of sedimentary organic matter in a rock and of its thermal evolution. Oil asphaltenes can be considered as reservoired kerogen moieties, and enable correlations with source-rock asphaltenes and parent kerogen. Asphaltene pyrolysis products are compositionally similar to the oil itself, when it has not suffered secondary alteration. Thus, pyrolysis of asphaltenes from degraded oils generates saturated hydrocarbon distributions similar to those of the original oil. Comparison of asphaltene pyrolysis products with the rock extract itself gives an indication of effects and degree of migration processes.

Pelet, R.; Behar, F.; Monin, J.C.

1986-01-01

66

Return migration.  

Science.gov (United States)

The author reviews the findings of the growing literature on return migration. Topics covered include typologies of return migrants, reasons for return, adaptation and readjustment of returnees, and the impact of return migration on the migrants' home societies. The focus of the study is on international return migration, migration to Northern Europe and northeastern North America, and return migration to the southern and eastern fringes of Europe and the Caribbean PMID:12264425

Gmelch, G

1980-01-01

67

Planet Migration  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Planet migration is the process by which a planet's orbital radius changes in time. The main agent for causing gas giant planet migration is the gravitational interaction of the young planet with the gaseous disk from which it forms. We describe the migration rates resulting from these interactions based on a simple model for disk properties. These migration rates are higher than is reasonable for planet survival. We discuss some proposed models for which the migration rates...

Lubow, Stephen H.; Ida, Shigeru

2010-01-01

68

rC5a directs the in vitro migration of human memory and naive tonsillar B lymphocytes: implications for B cell trafficking in secondary lymphoid tissues.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Human C5a is a potent chemoattractant for granulocytes, monocytes, and dendritic cells. In mice C5a has been shown to be chemotactic for germinal center (GC) B cells. To date, no information is available on the effects of C5a on human B cell locomotion. Here we demonstrate that rC5a increases polarization and migration of human tonsillar B cells. The locomotory response was due to both chemokinetic and chemotactic activities of rC5a. Moreover, memory and, at a lesser extent, naive B cell frac...

Malavasi, Fabio

1999-01-01

69

Hydrocarbon potential of Kuwait  

Energy Technology Data Exchange (ETDEWEB)

Potential reservoir and seal rocks were evaluated in onshore Kuwait based on lithological descriptions, and probable Permian, Triassic, Jurassic, and Lower Cretaceous source rocks have been identified in eastern Kuwait and along a depositional axis in central Kuwait west of the Burgan high. Time-temperature index (TTI) modeling and structural maps of selected stratigraphic horizons revealed that oil generated in these areas then migrated up-dip into the known production structural highs. Although deeper reservoirs in the known producing horizons appear to be prone to light oil-wet gas accumulations, based on thermal maturation studies, identification of these deep traps may show the greatest potential for additional hydrocarbon discoveries in Kuwait, as in the recent Kraa Al Maru discovery. The possible existence of stratigraphic traps not seen on seismic sections, but present on the oil migration pathways, is proposed. (Author)

Bou-Rabee, F.

2000-10-01

70

Ictericia obstructiva secundaria a migración de fragmentos de hepatocarcinoma a la vía biliar Obstructive jaundice secondary to hepatocellular carcinoma fragments migrated to common bile duct  

Directory of Open Access Journals (Sweden)

Full Text Available La ictericia obstructiva es una presentación poco común en un hepatocarcinoma (HC. Cuando en estos casos existe ictericia, habitualmente se debe a daño progresivo por cirrosis, o a infiltración tumoral extensa. El crecimiento o vaciamiento tumoral hacia la vía biliar se ha descrito ocasionalmente como causa de ictericia obstructiva. En raras ocasiones, puede tratarse de fragmentos de hepatocarcinoma que migran hacia la vía biliar, obstruyéndola. Presentamos un caso de ictericia obstructiva por migración de fragmentos de hepatocarcinoma a la vía biliar, en un paciente tratado 7 años antes por un HC, con resección curativa.Obstructive j aundice is a rare presentation of hepatocellular carcinoma (HC, and when it occurs, usually is due to progressive damage from cirrhosis, or extensive tumor infiltration. Tumor growth through the bile duct is being described with increasing frequency as a cause of obstructive j aundice. Rarely, it may be hepatocarcinoma fragments that migrate to the bile duct, obstructing it. We present a case of obstructive jaundice due to migration of fragments of hepatocellular carcinoma to the bile duct in a patient treated 7 years before, for an HC with a curative resection.

JUAN HEPP K

2010-08-01

71

Ictericia obstructiva secundaria a migración de fragmentos de hepatocarcinoma a la vía biliar / Obstructive jaundice secondary to hepatocellular carcinoma fragments migrated to common bile duct  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: Spanish Abstract in spanish La ictericia obstructiva es una presentación poco común en un hepatocarcinoma (HC). Cuando en estos casos existe ictericia, habitualmente se debe a daño progresivo por cirrosis, o a infiltración tumoral extensa. El crecimiento o vaciamiento tumoral hacia la vía biliar se ha descrito ocasionalmente c [...] omo causa de ictericia obstructiva. En raras ocasiones, puede tratarse de fragmentos de hepatocarcinoma que migran hacia la vía biliar, obstruyéndola. Presentamos un caso de ictericia obstructiva por migración de fragmentos de hepatocarcinoma a la vía biliar, en un paciente tratado 7 años antes por un HC, con resección curativa. Abstract in english Obstructive j aundice is a rare presentation of hepatocellular carcinoma (HC), and when it occurs, usually is due to progressive damage from cirrhosis, or extensive tumor infiltration. Tumor growth through the bile duct is being described with increasing frequency as a cause of obstructive j aundice [...] . Rarely, it may be hepatocarcinoma fragments that migrate to the bile duct, obstructing it. We present a case of obstructive jaundice due to migration of fragments of hepatocellular carcinoma to the bile duct in a patient treated 7 years before, for an HC with a curative resection.

HEPP K, JUAN; BALBONTÍN M, PAULINA; ARMAS M, RODOLFO; NAVARRETE G, CLAUDIO; RÍOS R, HORACIO; HUMERES A, ROBERTO; RODRÍGUEZ M, GABRIELA; ROA E, IVÁN.

72

Hydrocarbons Act  

Energy Technology Data Exchange (ETDEWEB)

Exploration research and mining of hydrocarbons, regulation of the petroleum by-products market, regulation of the supply of fuel gases through pipeline, entitlement to occupy the public domain, compulsory purchase orders, land requirements and limitations on ownership.

NONE

2002-07-01

73

Hydrocarbon Exploration  

Science.gov (United States)

To detect the hydrocarbon reservoir, structure traps should be detected. Seismic reflection profiles can be used to illustrate the structure image for the subsurface layers and hence, find out structure traps for oil. key words: Seismic reflection profiles, structural traps, oil potentialities,...

Tarabees, Elhamy

74

Apparatus for hydrocarbon extraction  

Science.gov (United States)

Systems and methods for hydrocarbon extraction from hydrocarbon-containing material. Such systems and methods relate to extracting hydrocarbon from hydrocarbon-containing material employing a non-aqueous extractant. Additionally, such systems and methods relate to recovering and reusing non-aqueous extractant employed for extracting hydrocarbon from hydrocarbon-containing material.

Bohnert, George W.; Verhulst, Galen G.

2013-03-19

75

Formation of secondary uranium minerals in the Koongarra deposit, Australia  

International Nuclear Information System (INIS)

Secondary uranium minerals from the Koongarra deposit, Northern Territory of Australia, were examined in order to understand the formation and alteration processes of the uranium minerals and their relevance to the migration behavior of uranium, lead, calcium and rare earth elements in the weathered zone. In most of the secondary ore zone, the only stable uranium mineral was saleeite (Mg(UO_2)_2(PO_4)_2·10H_2O), occurring as euhedral platy crystals up to 1 mm in length in veins and at surfaces. Apatite (Ca_5(PO_4)_3F), an accessory mineral of the host rock, has saleeite reaction rims, suggesting formation at the expense of apatite. Ca-uranyl phosphates, such as autunite (Ca(UO_2)_2(PO_4)_2·lOH_20), were not identified, and Ca-rich uranyl silicates are also absent in the primary ore zone. Pb-bearing uranyl phosphates were found only in the graphite layer cross-cutting the secondary ore zone. In the graphite layer, the local low oxidation condition and high hydrocarbonate content of ground water have affected the formation of uranium minerals and the migration behavior of uranium

1993-12-03

76

Formation of secondary uranium minerals in the Koongarra deposit, Australia  

Energy Technology Data Exchange (ETDEWEB)

Secondary uranium minerals from the Koongarra deposit, Northern Territory of Australia, were examined in order to understand the formation and alteration processes of the uranium minerals and their relevance to the migration behavior of uranium, lead, calcium and rare earth elements in the weathered zone. In most of the secondary ore zone, the only stable uranium mineral was saleeite (Mg(UO{sub 2}){sub 2}(PO{sub 4}){sub 2}{center_dot}10H{sub 2}O), occurring as euhedral platy crystals up to 1 mm in length in veins and at surfaces. Apatite (Ca{sub 5}(PO{sub 4}){sub 3}F), an accessory mineral of the host rock, has saleeite reaction rims, suggesting formation at the expense of apatite. Ca-uranyl phosphates, such as autunite (Ca(UO{sub 2}){sub 2}(PO{sub 4}){sub 2}{center_dot}lOH{sub 2}0), were not identified, and Ca-rich uranyl silicates are also absent in the primary ore zone. Pb-bearing uranyl phosphates were found only in the graphite layer cross-cutting the secondary ore zone. In the graphite layer, the local low oxidation condition and high hydrocarbonate content of ground water have affected the formation of uranium minerals and the migration behavior of uranium.

Isobe, Hiroshi [Japan Atomic Energy Research Institute, Ibaraki (Japan); Ewing, R.C. [Univ. of New Mexico, Albuquerque, NM (United States); Murakami, Takashi [Ehime Univ., Matsuyama (Japan)

1994-12-31

77

The Niger Delta Complex Basin: stratigraphy, structure and hydrocarbon potential  

Energy Technology Data Exchange (ETDEWEB)

The Agbada Formation is the major oil-producing formation in the Niger Delta Complex Basin, and overlies the Eocene Akata Formation, which is the principal hydrocarbon source rock. The Basin is deformed by large synsedimentary faults, roll-over anticlines and diapirs: hydrocarbon accumulations are largely controlled by growth faults. A review of the influence of the stratigraphic and structural features on the migration and accumulation of hydrocarbons is given in this paper. (author)

Chukwu, G.A. (Port Harcourt Univ. (Nigeria). Dept. of Petroleum Engineering)

1991-04-01

78

Hydrocarbon gases in canned cuttings from the Gravberg-1 well  

Energy Technology Data Exchange (ETDEWEB)

Hydrocarbons observed in the Gravberg-1 well were found only in trace amounts. Hydrocarbon gases with an abiogenic signature were only associated with the dolerite sills. This however, does not prove that migration of mantle gas took place, since the gases may have been emplaced with the magma. Inorganic reactions in crust may also explain the small amounts of hydrocarbon gas in the mafic rocks. 12 refs., 2 figs.

Laier, T. (Geological Survey of Denmark, Koebenhavn (Denmark))

1992-03-01

79

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...

2007-01-01

80

Spatial moment analysis for mass balance calculations and tracking movement of a subsurface hydrocarbon mound  

International Nuclear Information System (INIS)

Leaking underground storage tanks are a proven source of subsurface hydrocarbon contamination. An improbable leak scenario supported by anomalous field data formed the basis of a major lawsuit filed against a tank installer. A simplified hydrocarbon mound migration model, coupled with basic mass balance calculations, showed the field data to be inconsistent with the purported leak scenario, and showed monitoring well tampering to be the source of hydrocarbon contamination. The method described is a simple yet efficient means of developing hydrocarbon mass estimates and mound migration projections. These values can also be valuable in siting injection/extraction locations and developing integrated in situ remediation technologies

1993-01-01

 
 
 
 
81

International Migration and Remittances  

Directory of Open Access Journals (Sweden)

Full Text Available Human migration is a physical movement by human beings from one geographical areato another geographical area. Migration is internal as well as external. At theinternational level, no universally accepted definition for “Migrant” exists. The UniteNations defines “migration as an individual who has resided in a foreign country formore than one year irrespective of the causes, voluntary or involuntary, and the means,regular or irregular, used migrate”. Key terms of migrations is documented migration,economic migration, irregular migration, skilled migration, temporary workersmigration, internally displaced persons (IDP migration, refugee, stateless person, etc. .

Dattatray Sitaram Bagade

2012-08-01

82

Origin and mobility of hydrocarbon gases in alkaline plutons : the example of the Khibina complex, NW Russia  

Energy Technology Data Exchange (ETDEWEB)

The origin and distribution of abiogenic hydrocarbon gases (HCGs) was discussed with particular reference to HCGs in the Khibina pluton which are dominated by methane (CH{sub 4}) with minor amounts of higher hydrocarbons and hydrogen (H{sub 2}). Although isotopic data and hydrocarbon species ratios point to an abiogenic source, they do not distinguish between primary magmatic hydrocarbons and those generated by late magmatic re-speciation or post-magmatic Fischer-Tropsch (FT) synthesis. Some rock textures suggest limited CH{sub 4} production by FT synthesis, but the presence of primary, syn-magmatic CH{sub 4}-rich fluid inclusions, and the absence of primary and secondary carbon dioxide (CO{sub 2}) rich inclusions, suggest a dominantly early magmatic origin for the HCGs. The permeability and porosity in the Khibina pluton can be constrained by the distribution and geometry of fluid inclusion planes (FIPs) and open cracks (OCs), as well as by the magnitude and pathways of fluid flow. Orientation data for FIPs and OCs, obtained from oriented thin sections, revealed a range of orientations in sub-parallel arrays, suggesting continual re-activation of old fracture systems. The extensive occurrence of OCs and sealed FIPs points to long lived porosities and permeabilities with large fluid fluxes integrated over time. FIP and OC density values were found to be consistent with gas release patterns characterized by spontaneous release during mining of large volumes of HCG stored in a network of interconnected, sealed microfractures and fluid inclusion planes that unzip during stress. It was determined that the HCGs have a primary magmatic origin although there is local evidence for limited post-magmatic FT synthesis. Long term continuous gas migration has occurred within the complex through an interconnected set of fractures. FIPs represent aliquots of gas sealed during open system migration. It was concluded that the complex contains a potentially economically viable methane reservoir.

Treloar, P.J.; Beeskow, B.; Rankin, A.H. [Kingston Univ., Kingston upon Thames (United Kingdom). School of Earth Sciences; Potter, J. [Western Ontario Univ., London, ON (Canada). Dept. of Earth Science; Nivin, V. [Geological Inst., Apatity (Russian Federation). Kola Science Centre

2006-07-01

83

Polycyclic hydrocarbons and carcinogenesis  

Energy Technology Data Exchange (ETDEWEB)

This book contains 15 papers. Some of the titles are: Stereoselective metabolism and activation of polycyclic aromatic hydrocarbons; X-ray analyses of polycyclic hydrocarbon-DNA adducts: formation, detection, and characterization; The mutational consequences of DNA damage induced by benzo (a) pyrene; and the Bay region theory of polycyclic aromatic hydrocarbon carcinogenesis.

Harvey, R.G.

1985-01-01

84

Secondary parkinsonism  

Science.gov (United States)

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

85

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

Science.gov (United States)

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

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

2013-09-01

86

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...

87

Origin and migration of oil and gas. Proiskhozhdeniye i migratsiya nefti i gaza  

Energy Technology Data Exchange (ETDEWEB)

This paper provides reports presented at the republic conference (city of Lvov, April 81) which examined theoretical issues of petroleum geology from the position of biogenic and abiogenic synthesis of petroleum hydrocarbons. The processes that generate petroleum hydrocarbons, and that cause their migration and accumulation, as well as the various factors that promote oil- and gas-forming processes are analyzed.

1984-01-01

88

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)

2005-02-28

89

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

90

Flash pyrolysis of silicon-bound hydrocarbons  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Curie-point flash pyrolysis-gas chromatography/mass spectrometry of n-octadecane, n-propylbenzene and n-propylcyclohexane chemically linked to silica has been performed in order to gain a better understanding of the mechanism of flash pyrolysis by which hydrocarbons are generated from kerogens. The major products result via a 6-membered ring rearrangement involving the Si---O---C linkage and from cleavage of C---C bonds allylic to primary or secondary alkyl radicals

Sinninghe Damste?, J. S.; Hartgers, W. A.; Leeuw, J. W.

1991-01-01

91

Cloud migration research: a systematic review  

Digital Repository Infrastructure Vision for European Research (DRIVER)

BACKGROUND--By leveraging cloud services, organizations can deploy their software systems over a pool of resources. However, organizations heavily depend on their business-critical systems, which have been developed over long periods. These legacy applications are usually deployed on-premise. In recent years, research in cloud migration has been carried out. However, there is no secondary study to consolidate this research.

2013-01-01

92

Secondary trauma.  

Science.gov (United States)

A review of secondary trauma is presented. Secondary trauma involves the transfer and acquisition of negative affective and dysfunctional cognitive states due to prolonged and extended contact with others, such as family members, who have been traumatized. As such, secondary trauma refers to a spread of trauma from the victim to those who have close contact with the traumatized individual. It is claimed by some that exposure to intense video presentations of traumatic events can also lead to secondary traumatization. Assessment devices are reviewed and most of these appear to be designed to assess secondary or vicarious traumatization in therapists rather than in the general population. Most scales lack cutoff scores and this is a significant weakness. The modified Stroop procedure is presented as a non-paper and pencil method of assessing secondary trauma reactions. The evaluation of the efficacy of therapeutic interventions for secondary traumatization is virtually non-existent. Systematic studies of secondary trauma are in their infancy and a good deal of further research is needed. PMID:19278145

Motta, Robert W

2008-01-01

93

Geology of Hydrocarbons Visualizations  

Science.gov (United States)

This site has over two dozen animations about hydrocarbons as energy sources, including where resources are found, the amount of each energy source/type used in the US and in the world, how hydrocarbons are formed, and how they are found by exploration geologists.

US Geological Survey Western Earth Surface Processes Team; National Park Service.

94

Hydrocarbon Spectral Database  

Science.gov (United States)

SRD 115 Hydrocarbon Spectral Database (Web, free access)   All of the rotational spectral lines observed and reported in the open literature for 91 hydrocarbon molecules have been tabulated. The isotopic molecular species, assigned quantum numbers, observed frequency, estimated measurement uncertainty and reference are given for each transition reported.

95

Hydrocarbon fuels from biomass  

Energy Technology Data Exchange (ETDEWEB)

With a view to developing petro-crops as a source of hydrocarbon fuels, indigeneous laticiferous species belonging to the families Euphorbiaceae, Asclepiadaceae and Convolvulaceae have been evaluated for their biocrude potential. Hydrocracking of biocrude, from E. royleana, E. neriifolia, Cryptostegia grandiflora and Calotropis gigantea to hydrocarbon fuels, preferably middle distillates, has been demonstrated. 26 refs., 6 tabs.

Bhatia, V.K.; Mittal, K.G.; Mehrotra, R.P.; Mehrotra, M.

1989-04-01

96

Recovering hydrocarbons from hydrocarbon-containing vapors  

Energy Technology Data Exchange (ETDEWEB)

Values are recovered from a hydrocarbon-containing vapor by contacting the vapor with quench liquid consisting essentially of hydrocarbons to form a condensate and a vapor residue, the condensate and quench fluid forming a combined liquid stream. The combined liquid stream is mixed with a viscosity-lowering liquid to form a mixed liquid having a viscosity lower than the viscosity of the combined liquid stream to permit easy handling of the combined liquid stream. The quench liquid is a cooled portion of the mixed liquid. Viscosity-lowering liquid is separated from a portion of the mixed liquid and cycled to form additional mixed liquid.

Mirza, Zia I. (La Verne, CA); Knell, Everett W. (Los Alamitos, CA); Winter, Bruce L. (Danville, CA)

1980-09-30

97

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

1987-01-01

98

Simulated oil migration in biothermic Late Devonian-Early Carboniferous formations of Bashkiria  

Energy Technology Data Exchange (ETDEWEB)

This paper discusses a new approach for studying the migration processes of hydrocarbons, which consists of a detailed geologic-geochemical analysis of the core sample material along the entire migration path from the source to the pool. It examines the migration process in biothermic Late Devonian-Early Carboniferous formations in Bashkiria. As a result of the research, the source of the oil, migration direction, oil migration paths along the collector, and changes in its composition from source to pools have been determined.

Zhuze, N.G.; Shapiro, A.I.; Tarasova, T.G.; Voronkova, Ya.N.

1984-01-01

99

Model migration schedules incorporating student migration peaks  

Directory of Open Access Journals (Sweden)

Full Text Available This paper proposes an extension of the standard parameterised model migration schedule to account for highly age-concentrated student migration. Many age profiles of regional migration are characterised by sudden 'spiked' increases in migration intensities in the late teenage years, which are related to leaving school, and, in particular, to entry into higher education. The standard model schedule does not appear to be effective in describing the pattern at these ages. This paper therefore proposes an extension of the standard model through the addition of a student curve. The paper also describes a relatively simple Microsoft Excel-based fitting procedure. By way of illustration, both student peak and standard model schedules are fitted to the age patterns of internal migration for two Australian regions that experience substantial student migration. The student peak schedule is shown to provide an improved model of these migration age profiles. Illustrative population projections are presented to demonstrate the differences that result when model migration schedules with and without student peaks are used.

Tom Wilson

2010-07-01

100

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

 
 
 
 
101

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

102

Dehydrogenation of dehydrogenatable hydrocarbons  

International Nuclear Information System (INIS)

This patent describes a process for the dehydrogenation of a dehydrogenatable hydrocarbon with separate and intermediate selective oxidation of hydrogen which comprises the steps of: (a) contacting the hydrocarbon with a dehydrogenation catalyst comprising an alkaline metal-promoted iron compound in a first-reaction dehydrogenation zone in the presence of steam at dehydrogenation conditions to produce a first-reaction dehydrogenation zone effluent stream comprising a mixture of unconverted hydrocarbons, dehydrogenated hydrocarbons, hydrogen and steam; (b) removing the first-reaction dehydrogenation zone effluent from the first-reaction dehydrogenation zone; (c) passing the effluent of step (b) to a second-reaction oxidation zone, which is separate and discrete from the first-reaction dehydrogenation zone; (d) contacting the first-reaction dehydrogenation zone effluent in the second-reaction oxidation zone with an oxygen-containing gas to selectively oxidize the hydrogen; (e) withdrawing the unconverted and dehydrogenated hydrocarbons from the second-reaction oxidation zone having an increased temperature with respect to the temperature of the first-reaction dehydrogenation zone effluent; (f) passing the removed second-reaction oxidation zone product stream of step (e) to a third-reaction dehydrogenation zone containing a dehydrogenation catalyst comprising an alkaline metal promoted iron compound at dehydrogenation conditions to produce dehydrogenated hydrocarbons; and, (g) withdrawing and recovering the dehydrogenated hydrocarbons, the improvement which comprises utilizing as the support a cerium-containing alumina

1987-01-01

103

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1995-10-01

104

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

2004-03-01

105

Population and International Migration.  

Science.gov (United States)

International migration is a conspicous form of population interaction between richer and poorer countries. The paper makes an assessment of the dimensions of past and present day migration, its determinants, the effects on sending countries, costs and be...

G. Swamy

1985-01-01

106

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

107

Hydrocarbon toxicity: A review.  

Science.gov (United States)

Abstract Context. Clinical effects of hydrocarbon exposure have been reported since 1897. These substances are ubiquitous, and their exposures are common. The specific hydrocarbon and route of exposure will determine the clinical effect, and an understanding of this is helpful in the care of the hydrocarbon-exposed patient. Objective. To complete a comprehensive review of the literature on hydrocarbon toxicity and summarize the findings. Methods. Relevant literature was identified through searches of Medline (PubMed/OVID) and Cochrane Library databases (inclusive of years 1975-2013), as well as from multiple toxicology textbooks. Bibliographies of the identified articles were also reviewed. Search terms included combinations of the following: hydrocarbons, inhalants, encephalopathy, coma, cognitive deficits, inhalant abuse, huffing, sudden sniffing death, toluene, renal tubular acidosis, metabolic acidosis, arrhythmia, dermatitis, and aspiration pneumonitis. All pertinent clinical trials, observational studies, and case reports relevant to hydrocarbon exposure and published in English were reviewed. Chronic, occupational hydrocarbon toxicity was not included. Results. Exposure to hydrocarbons occurs through one of the following routes: inhalation, ingestion with or without aspiration, or dermal exposure. Inhalational abuse is associated with central nervous system depression, metabolic acidosis, and arrhythmia. The exact mechanism of the CNS depression is unknown, but experimental evidence suggests effects on NMDA, dopamine, and GABA receptors. Chronic toluene inhalation causes a non-anion gap metabolic acidosis associated with hypokalemia. Halogenated hydrocarbon abuse can cause a fatal malignant arrhythmia, termed "sudden sniffing death". Individuals who regularly abuse hydrocarbons are more likely to be polysubstance users, exhibit criminal or violent behavior, and develop memory and other cognitive deficits. Heavy, long-term use results in cerebellar dysfunction, encephalopathy, weakness, and dementia. Neuroimaging may demonstrate leukoencephalopathy in these cases. Acute exposures improve with cessation of exposure. Electrolyte and fluid replacement will improve metabolic acidosis. Arrhythmias are precipitated via catecholamine surge, and beta blockers are presumed protective. Aspiration of hydrocarbons causes a potentially fatal pneumonitis. Symptoms may include cough, wheezing respiratory distress, and hypoxia. Bilateral interstitial infiltrates may be delayed for several hours after the development of pneumonitis. Treatment consists of supportive care, supplemental oxygen, and may require intubation and admission to an intensive care unit in severe cases. Unfortunately, aspiration pneumonitis remains a leading cause of poisoning mortality in children. Dermal exposure can cause dermatitis, chemical burns, and defatting injury. Oral exposure can cause local irritation as well as vomiting, diarrhea, and abdominal pain. Conclusion. Acute hydrocarbon exposure can result in a wide array of pathology, such as encephalopathy, pneumonitis, arrhythmia, acidosis, and dermatitis. Intentional inhalational and accidental ingestion exposures with aspiration lead to the greatest morbidity and mortality. PMID:24911841

Tormoehlen, L M; Tekulve, K J; Nañagas, K A

2014-06-01

108

Marriage, money and migration  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

2009-01-01

109

Essays on temporary migration  

Digital Repository Infrastructure Vision for European Research (DRIVER)

My thesis dissertation focuses on the temporariness of migration, its diverse effects as well as on migration selection. The first paper, A Dynamic Model of Return Migration analyzes the decision process underlying return migration using a dynamic model. We explain how migrants decide whether to stay or to go back to their home country together with their savings and consumption decisions. We simulate our model with return intentions and perform policy simulations. The se...

Mestres Domenech, J.

2012-01-01

110

Oil migration and microfossils  

Energy Technology Data Exchange (ETDEWEB)

This paper presents a critical analysis of a method utilizing microfossils to determine the paths of migration and the intervals of possible oil reflux. It is concluded that the study of the composition of the ''migrating'' portion of microfossils does not make it possible to determine the direction of oil migration; nor do the intervals between such activity.

Yeremenko, N.A.

1984-01-01

111

Hydrocarbons of Marine Phytoplankton.  

Science.gov (United States)

The hydrocarbon contents of 23 species of algae (22 marine planktonic), belonging to 9 algal classes, were analyzed. The highly unsaturated 3,6,9,12,15,18-heneicosahexaene predominates in the Bacillariophyceae, Dinophyceae, Cryptophyceae, Haptophyceae and...

M. Blumer R. R. L. Guillard T. Chase

1970-01-01

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.)

1981-01-01

113

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

1993-12-02

114

Process for treating 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 solid acidic material which may consist of activated charcoal, silica gel, alumino-silicate molecular sieve material, Fuller's earth, activated titanium dioxide, anhydrous CuSO_4, or a mixture of two or more of these materials of surface area at least 5 m"2/g. Activated charcoal of surface area 500 to 2000 m"2/g is preferred and may be in the form of column packing, the hydrocarbons being passed through the column at a rate of 5 to 10 column volumes per hour. (U.K.)

1978-01-01

115

Petroleum generation and migration from Talang Akar coals and shales offshore N. W. Java, Indonesia  

Energy Technology Data Exchange (ETDEWEB)

The Oligocene Talang Akar formation is the major source for petroleum (oil and gas) in the Ardjuna sub-basin. Source rock quality varies within the deltaic to marginal marine complex, with coals deposited on the lower delta plain being distinctly oil-prone, whereas the surrounding delta plain shales are largely gas-prone. Shales and 'drifted' coals laid down in marine-influenced interdistributary bay environments show increasingly oil-prone characteristics, possibly due to preferential transport of hydrogen-rich plant components to more distal setting. Molecular characteristics of the coals and shales are similar, with higher plant (angiosperm) biomarkers and their aromatic derivatives occurring widely. Kinetic studies of hydrocarbon generation, and simulated maturation experiments using hydrous pyrolysis, indicate that the delta plain coals are the major source for crude oils in the basin, with a secondary, but minor contribution from marine-influenced interdistributary bay shales. Delta plain shales are interpreted to expel gaseous products only. The stratigraphic and spatial location of oil and gas fields were examined with respect to their position relative to oil and gas generating source rocks. The field distribution could not be explained in terms of source rock geochemistry alone, and phase behaviour of petroleum during secondary migration was shown to exert an important influence on the distribution of oil and gas deposits in the basin. 38 refs., 10 figs., 3 tabs.

Noble, R.A.; Wu, C.H.; Atkinson, C.D. (ARCO Oil and Gas Co., Plano, TX (USA))

1991-01-01

116

Sulfidization and magnetization above hydrocarbon reservoirs  

Energy Technology Data Exchange (ETDEWEB)

Geochemical and rock magnetic studies of strata over Cement oil field (Anadarko basin, Oklahoma), Simpson oil field (North Slope basin, Alaska), and the Edwards deep gas trend, south Texas coastal plain, document changes in original magnetizations caused by postdepositional iron sulfide minerals that are, or may be, related to hydrocarbon seepage. At Cement, ferrimagnetic pyrrhotite (Fe{sub 7}S{sub 8}) formed with pyrite and marcasite in Permian red beds. The Fe-S minerals contain isotopically heavy, abiogenic sulfur derived from thermal degradation of petroleum and (or) isotopically light sulfur derived from sulfate-reducing bacteria fed by leaking hydrocarbons. At Simpson, ferrimagnetic greigite (Fe{sub 3}S{sub 4}) dominates magnetizations in Upper Cretaceous nonmarine beds that contain biodegraded oil. Sulfur isotopic data are consistent with, but do not prove, a genetic link between the greigite ({delta}{sup 34}S {gt} +20 per mil) and seepage. In middle Tertiary sandstones of southeast Texas, pyrite and marcasite formed when abiogenic H{sub 2}S migrated upward from deep reservoirs, or when H{sub 2}S was produced at shallow depths by bacteria that utilized organic material dissolved in migrating water from depth. The sulfide minerals replaced detrital magnetite to result in a systematic decrease in magnetic susceptibility toward faults that connect deep petroleum reservoirs to shallow sandstone. The authors results show that abiologic and biologic mechanisms can generate magnetic sulfide minerals in some sulfidic zones of hydrocarbon seepage. The magnetizations in such zones are diminished most commonly by replacement of detrital magnetic minerals with nonmagnetic sulfide minerals or are unchanged if such detrital minerals were originally absent.

Reynolds, R.L.; Goldhaber, M.B.; Tuttle, M.L. (U.S. Geological Survey, Denver, CO (United States))

1991-03-01

117

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

118

Hydrocarbon fuel systems  

Energy Technology Data Exchange (ETDEWEB)

This patent describes a low Reid Vapor Pressure liquid gasoline for use in a standard carbureted internal combustion engine. It comprises: a priming agent and a hydrocarbon mixture having an intermediate carbon range relative to C{sub 4}-C{sub 12} fuel; the intermediate carbon range consisting essentially of C{sub 6}-C{sub 10} hydrocarbons with C{sub 9} and C{sub 10} paraffinic hydrocarbons being present in the mixture; the gasoline having a boiling point range of 121{degrees} F.-345{degrees} F. at 1 atmosphere pressure; and the priming agent consisting of a hydrocarbon selected from the priming agent consisting of C{sub 4} and C{sub 5} hydrocarbons and mixtures thereof and the priming agent being present in a minimum effective amount for raising the front end volatility of the gasoline to a minimum level for cold engine starting with the minimum effective amount being less than that required for C{sub 4}-C{sub 12} gasoline.

Talbert, W.L.

1991-05-14

119

Renewable resources (hydrocarbons)  

Energy Technology Data Exchange (ETDEWEB)

Rising energy prices and an oil-based economy are cited as motivation to seek hydrocarbons similar to petroleum from renewable sources. Previous work (rubber tree, ethanol from carbohydrate crops, methanol from forest or plantation trees) is reviewed as well as past and current efforts to find species of plants with high hydrocarbon content, in which the molecular weight is similar to that of petroleum. Yields of hydrocarbons obtainable (4 tons/acre/yr in the case of rubber trees) are cited as well as biochemical pathways leading to various hydrocarbons. Guayule rubber plants are discussed as well as the economics and technology involved in processing. Specific ''Oil Plants'' are discussed in some detail. These include Euphorbia species and croton. Algae (Botryococcus braunii) is cited as containing 75% hydrocarbons (dry weight), which after processing yields glycerol, pigment, and protein. Plants such as sunflower, soya bean, palm, etc. yield vegetable oils which may be used as a diesel substitute. It is concluded that decisions concerning the use of oil containing plants for fuel will be based on economic and political considerations. 23 references. (MJJ)

Hall, D.O.

1981-06-01

120

Migration and Environmental Hazards  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Losses due to natural hazards (e.g., earthquakes, hurricanes) and technological hazards (e.g., nuclear waste facilities, chemical spills) are both on the rise. One response to hazard-related losses is migration, with this paper offering a review of research examining the association between migration and environmental hazards. Using examples from both developed and developing regional contexts, the overview demonstrates that the association between migration and environmental hazards varies b...

Hunter, Lori M.

2005-01-01

 
 
 
 
121

Determinants of international migration  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Migrations have occurred throughout human history. Today, people inhabit virtually every corner of the world. In fact, given the upsurge in the last few decades, more people are on the move today than at any other point in time. In order to get an understanding of the driving forces shaping migration patterns across countries and within destinations, this dissertation investigates the determinants of bilateral international migration and the location choice of immigrants with particular atten...

Ruyssen, Ilse

2013-01-01

122

International migration - OECD  

... Closing remarks: - Freddy Montero, Deputy Minister, Ministry of the Interior and the Police, Costa Rica- Hélène Bourgade, Head of Unit, Employment, Social Inclusion, Migration, European Commission- Mario Pezzini, Director of the OECD Development Centre The pictures of this event are available here To follow the futur developments of this project, on twitter use #MigrationDev   Related Documents   Workshop on Strengthening the Migration-Development Nexus through Improved Policy and Institutional Coherence Seminar on migration and development with Professor Paul Collier   Countries list A-C ...

123

Electrochemical masstransfer of oil hydrocarbons in dispersed soils  

Energy Technology Data Exchange (ETDEWEB)

A large-scale pollution of the geological environment is a result of imperfect processes of mining, refining, haul of oil and irrational use of petroleum. The processes of masstransfer of hydrocarbons in dispersed soils and the problems of forming of a dual electric layer (DEL) on the demarcations 'water-oil' and 'mineral-water' are still insufficiently studied. Therefore, one of the most important problems in the field of the ecological geology is the analysis of ways of cleaning of soils from hydrocarbons. The kaolinitic clay from the Tirlianskoye deposit (K{sub 2}, st. Jabik, Bashkiria) and average polymineral loam (prlllkl, Moscow region, the south-east of town Zvenigorod) was chosen as the objects of the experimental study. The mixture of West Siberian oils was used for model pollution. The experimental laboratory researches of electrochemical migration of hydrocarbons were carried out on dispersiblis clayey soils. (orig.)

Nekrasova, M.A.; Zvolinsky, V.P.; Kanev, M.V. [Russian Friendship Peoples Univ., Dept. of Eecological Monitoring and Forecasting, Moscow (Russian Federation)

2001-07-01

124

Miscellaneous hydrocarbon solvents.  

Science.gov (United States)

The solvents discussed in this article are common solvents not categorized as halogenated, aromatic, or botanical. The solvents discussed are categorized into two groups: hydrocarbon mixtures and single agents. The hydrocarbon mixtures discussed are Stoddard solvent, naphtha, and kerosene. The remaining solvents described are n-hexane, methyl n-butyl ketone, dimethylformamide, dimethyl sulfoxide, and butyl mercaptans. Effects common to this group of agents and their unique effects are characterized. Treatment of exposures and toxic effects of these solvents is described, and physiochemical properties and occupational exposure levels are listed. PMID:15325316

Bebarta, Vikhyat; DeWitt, Christopher

2004-08-01

125

Air Quality Criteria for Hydrocarbons.  

Science.gov (United States)

This document focuses on gas-phase hydrocarbons and certain of their oxidation products, particularly aldehydes, that are associated with the manifestations of photo-chemical air pollution. Particulate hydrocarbons, and more specifically polynuclear hydro...

1970-01-01

126

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

127

Evaluation of hyperspectral imagery for detecting hydrocarbon microseepage  

Energy Technology Data Exchange (ETDEWEB)

Loark Producing Company (Loark) of Jackson, Mississippi, is a small consulting organization providing services for hydrocarbon exploration. Current methods used for {open_quotes}finding oil{close_quotes} include geophysics, geochemistry, geobotany, and surface mapping, but these techniques are not definitive. The oil and gas industries primary goal is to minimize the initial economic risk associated with hydrocarbon exploration. Loark is participating in a Visiting Investigator Program (VIP) project at Stennis Space Center in cooperation with the Mississippi Office of Geology to explore the use of hyperspectral imaging to detect hydrocarbon microseepage. Extensive evidence in favor of vertical migration of hydrocarbon from subsurface petroleum reservoirs has been presented during the past 30 years. Migrating volatiles from reservoirs can alter surface rocks, thus changing their weathering characteristics or producing soil environments containing higher concentrations of iron and manganese that can in turn contaminate surface vegetation or alter growth patterns. The ability to detect indicator species, vegetation stress, and/or forest structure dynamics provides a potential methodology for hydrocarbon detection and exploration. The effects of vegetation stress from microseepage are subtle in nature and are not readily apparent using broad-band sensors, such as TM or SPOT. It is hypothesized that hyperspectral airborne sensors, having narrower spectral bandwidths and higher spatial resolutions, may provide improved discriminatory ability for detecting vegetation stress due to microseepage. In this study, geochemical data are being utilized for preliminary determination of microseepage sites. High spectral resolution GER Mark V data of both control and microseepage sites have been acquired and analyzed to examine hydrocarbon microseepage evidence. High spectral and high spatial resolution airborne TRWIS-B sensor data of these sites have also been acquired.

Zhikang Chen; Ahl, D.; Albasini, J. [Stennis Space Center, MS (United States)] [and others

1996-07-01

128

Selecting hydrocarbon rocket propulsion technology  

Science.gov (United States)

Past studies have shown that the dry weight of future earth-to-orbit vehicles can be reduced by the combined use of hydrogen and hydrocarbon propulsion compared to all-hydrogen propulsion. This paper shows that the use of certain hydrocarbon engines with hydrogen engines produces the lowest vehicle dry mass. These hydrocarbon engines use propane or RP-1 fuel, hydrogen cooling, and hydrogen-rich gas generators. Integration of the hydrogen and hydrocarbon nozzles is also beneficial.

Martin, J. A.

1986-01-01

129

The Migration Game  

Science.gov (United States)

This site features an interactive Migration Game created by the Migratory Bird Center at the Smithsonian National Zoological Park. In it, you can help Wanda the Wood Thrush travel from her winter home in Costa Rica to her summer home in Maryland by answering questions regarding migration in general and specific migratory habits of the wood thrush.

2008-01-01

130

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

131

Photon absorptiometry of hydrocarbons  

International Nuclear Information System (INIS)

Measured and parametrised values of the attenuation coefficients of several hydrocarbons having a hydrogen-to-carbon weight ratio in the range from 0.05 to 0.16 and for photon energies 33, 75, 145, 279 and 662 keV are presented. The values are compared and possible trends and applications discussed. (author)

1986-01-01

132

Frontières et migrations - Introduction  

Directory of Open Access Journals (Sweden)

Full Text Available Ce dossier met en relation deux champs de recherche étroitement liés car les frontières servent à maîtriser les migrations et les migrations se mesurent parce qu’il y a des frontières, intérieures et extérieures. Aujourd’hui, sommes-nous entrés dans une « Obsession des frontières », comme l’a écrit Michel Foucher, ou au contraire, comme nous y invite Régis Debray (Eloge des frontières faut-il voir dans les frontières le creuset de la définition des appartenances communes ? -- The Borders and Migrations « dossier » connects two fields of research closely interrelated: borders are generally used to control migration and migrations are measured because there are frontiers, be they domestic, international or symbolic. Have we entered an era of « obsession with borders » like Michel Foucher would write it, or, on the contrary, should we see borders as the place for the definition of collective belongings, just as in Regis Debray’s In Praise of Borders ?

Catherine de Wenden

2013-10-01

133

Suicidal Ideation and Migration Aspirations among Youth in Central Mexico  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Steven Hoffman

2013-01-01

134

The brown dwarf desert as a consequence of orbital migration  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We show that the dearth of brown dwarfs in short-period orbits around Solar-mass stars - the brown dwarf desert - can be understood as a consequence of inward migration within an evolving protoplanetary disc. Brown dwarf secondaries forming at the same time as the primary star have masses which are comparable to the initial mass of the protoplanetary disc. Subsequent disc evolution leads to inward migration, and destruction of the brown dwarf, via merger with the star. This ...

Armitage, Philip J.; Bonnell, Ian A.

2001-01-01

135

Mantle hydrocarbons: abiotic or biotic?  

Science.gov (United States)

Analyses of 227 rocks from fifty localities throughout the world showed that mantle derived rocks such as tectonized peridotites in ophiolite sequences (tectonites) arid peridotite xenoliths in alkali basalts contain heavier hydrocarbons (n-alkanes), whereas igneous rocks produced by magmas such as gabbro arid granite lack them. The occurrence of hydrocarbons indicates that they were not derived either from laboratory contamination or from held contamination; these compounds found in the mantle-derived rocks are called here "mantle hydrocarbons." The existence of hydrocarbons correlates with petrogenesis. For example, peridotite cumulates produced by magmatic differentiation lack hydrocarbons whereas peridotite xenoliths derived from the mantle contain them. Gas chromatographic-mass spectrometric records of the mantle hydrocarbons resemble those of aliphatics in meteorites and in petroleum. Features of the hydrocarbons are that (a) the mantle hydrocarbons reside mainly along grain boundaries and in fluid inclusions of minerals; (b) heavier isoprenoids such as pristane and phytane are present; and (c) delta 13C of the mantle hydrocarbons is uniform (about -27%). Possible origins for the mantle hydrocarbons are as follows. (1) They were in organically synthesized by Fischer-Tropsch type reaction in the mantle. (2) They were delivered by meteorites and comets to the early Earth. (3) They were recycled by subduction. The mantle hydrocarbons in the cases of (1) and (2) are abiogenic and those in (3) are mainly biogenic. It appears that hydrocarbons may survive high pressures and temperatures in the mantle, but they are decomposed into lighter hydrocarbon gases such as CH4 at lower pressures when magmas intrude into the crust; consequently, peridotite cumulates do not contain heavier hydrocarbons but possess hydrocarbon gases up to C4H10. PMID:11541663

Sugisaki, R; Mimura, K

1994-06-01

136

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

137

Women in migration.  

Science.gov (United States)

This special issue reflects the belated but growing scholarly appreciation of the specificity and importance of women in migration. Aside from the sheer numerical significance of female migration documented in this issue, women migrants encounter problems and make special contributions which render comprehension of their specificity critical to an understanding of international migration in general. In an introductory essay, Morokvasic surveys the state of knowledge concerning women in migration. The focus then shifts, in Part II, to regional and national case studies which collectively elucidate the multifaceted dimensions of the women in migration research issue through time and space. In Part III, an international comparison of female immigrants and their labor market characteristics reveals striking similarities but also important differences. The US Canada and Australia can be discretely compared through 5 census-based quantitative analyses. The role of migrant women in the labor market is also the theme of Part IV. But the 5 studies comprising this section are based on survey research or on discernible global trends in migration and employment. Part V is devoted to the theme of female rural to urban migration in the Third World. PMID:12280253

Morokvasic, M

1984-01-01

138

Geology and hydrocarbon accumulations, Columbus basin, offshore Trinidad  

Energy Technology Data Exchange (ETDEWEB)

The Columbus basin, on the eastern shelf of Trinidad, lies at the eastern extremity of a belt of severe deformation along the northern boundary of South America that has been affected by compressional and wrench tectonics in the Pliocene-Pleistocene. Two major structural trends are present in the Columbus basin: a series of ENE-trending anticlines and NNW-oriented normal faults. The basin was filled during the late Miocene to Holocene with sediments deposited by an ancestral Orinoco River draining a hinterland to the southwest. The Pliocene-Pleistocene section, which contains the hydrocarbon accumulations in the Columbus basin, was laid down in three coarsening-upward sedimentary sequences followed by a late Pleistocene transgressive sequence. Traps for hydrocarbon accumulation were formed by an easterly trending Pliocene-Pleistocene wrench system with associated ENE-oriented anticlines combined with NNW-oriented normal faults. Oil was sourced in the late Miocene lower Cruse Formation, whereas gas was derived both from Pliocene-Pleistocene pro-delta shales and as a late high temperature phase of lower Cruse hydrocarbon generation. The NNW faults formed migration conduits from the oil source rock to Pliocene-Pleistocene reservoirs. The temporal relationship of faulting to oil generation is a major factor affecting the distribution of oil and gas. The size of hydrocarbon accumulations is limited to some extent by a lack of an effective hydrocarbon seal, particularly in the western half of the basin.

Leonard, R.

1983-03-01

139

Geology and hydrocarbon accumulations, Columbus Basin, Offshore Trinidad  

Energy Technology Data Exchange (ETDEWEB)

The Columbus basin, situated on the eastern shelf of Trinidad, lies at the eastern extremity of a belt of severe deformation along the northern boundary of South America that has been affected by compressional and wrench tectonics in Pliocene-Pleistocene time. Two major structural trends are present in the Columbus basin: a series of east-northeast trending anticlines and northnorthwest oriented normal faults. The basin was filled during late Miocene to Holocene time with sediments deposited by an ancestral Orinoco River draining a hinterland to the southwest. The Pliocene-Pleistocene section, which contains the hydrocarbon accumulations in the Columbus basin, was deposited in three coarseningupward sedimentary sequences followed by a late Pleistocene transgressive sequence. Traps for hydrocarbon accumulation were formed by an easterly trending Pliocene-Pleistocene wrench system with associated east-northeast-oriented anticlines combined with north-northwest-oriented normal faults. Oil was sourced in the late Miocene lower Cruse Formation, whereas gas was derived both from Pliocene-Pleistocene pro-delta shales and as a late high-temperature phase of lower Cruse hydrocarbon generation. The northnorthwest faults formed migration conduits from the oil source rock to Pliocene-Pleistocene reservoirs. The temporal relationship of faulting to oil generation is a major factor affecting the distribution of oil and gas. The size of hydrocarbon accumulations is limited to some extent by a lack of an effective hydrocarbon seal, particularly in the western half of the basin.

Leonard, R.

1983-07-01

140

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

 
 
 
 
141

Tectonic control in source rock maturation and oil migration in Trinidad  

Energy Technology Data Exchange (ETDEWEB)

Oil accumulation in Trinidad were sourced by the Upper Cretaceous calcareous shales deposited along the Cretaceous passive margin of northern South America. Maturation of these source rocks, oil generation, migration and re-migration occurred in a foreland basin setting that resulted from interaction between Caribbean and South American plates during Late Oligocene to recent times. During Middle Miocene-Recent times, the foreland basin experienced strong compressional events, which controlled generation, migration, and accumulation of oil in Trinidad. A series of mature source rock kitchens formed in Late Miocene-Recent times in the Southern and Colombus Basins to the east-southeast of the Central Range Thrust. This thrust and associated fratured developed around 12 m.y.b.p. and served as vertical migration paths for the oil generated in Late Miocene time. This oil migrated into submarine fans deposited in the foreland basin axis and older reservoirs deformed into structural traps. Further generation and migration of oil, and re-migration of earlier oil took place during Pliocene-Holocene times, when later thrusting and wrench faulting served as vertical migration paths. Extremely high sedimentation rates in Pliocene-Pleistocene time, concurrent with active faulting, was responsible for very rapid generation of oil and gas. Vertically migrating gas often mixed with earlier migrated oil in overlying reservoirs. This caused depletion of oil in light hydrocarbons with accompanied fractionation among hydrocarbon types resulting in heavier oil in lower reservoirs, enrichment of light hydrocarbons and accumulation of gas-condensates in upper reservoirs. This process led to an oil-gravity stratification within about 10,000 ft of section.

Persad, K.M.; Talukdar, S.C.; Dow, W.G. (DGSI, The Woodlands, TX (United States))

1993-02-01

142

Membrane separation of hydrocarbons  

Science.gov (United States)

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

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

1986-01-01

143

Hydrocarbon accumulations on the Dead Sea graben: a simulation approach  

Energy Technology Data Exchange (ETDEWEB)

A modelling study aimed at providing a better understanding of the hydrocarbon accumulations on the South West flank of the Dead Sea graben in Israel has been performed. It considers the recent geochemical finding that the source rock of the hydrocarbon occurrences in the area is the Senonian bituminous chalk and marl, buried in the central Dead Sea graben. The study investigates the effect of the regional geological and hydrogeological conditions, associated with the physical properties of the rock and fluids, on the migration and types of hydrocarbon accumulations. The investigation was performed by means of a three-phase, two-dimensional, numerical reservoir simulator. Typical cross-sections, through potential anticlinal hydrocarbon traps, were considered. The study analyses possible hydrodynamic flushing in the water-flow direction, as well as counter-current migration in a direction opposite to the potentiometric water gradients, from the Dead Sea graben upwards. In addition to conventional hydrodynamic traps, the study includes the case of downdip entrapment due to low permeability regions. It is concluded that from the hydrodynamic point of view, the easiest oil migration path is through Paleozoic - Triassic formations. The high water salinity of these beds facilities the up-structure oil flow, in a direction opposite to the water current movement. The Jurassic beds are probably impregnated by oil and gas coming from Triassic strata through faults. Undiscovered structural traps are likely to contain mostly gas and down-faulted blocks adjacent to sealing faults, or to low-permeable regions (including permeable faults), are potential oil traps. (author)

Braester, C. (Technion-Israel Inst. of Tech., Haifa (Israel)); Fligelman, H.; Kashai, E. (Oil Exploration (Investment) Ltd., Tel-Aviv (Israel))

1991-04-01

144

Hydrocarbon conversion catalysts  

Energy Technology Data Exchange (ETDEWEB)

A catalyst, having a specified amount of rare earth metal content and a specified amount of alkali metal content, suitable for conversion of hydrocarbon oils to lower boiling products comprises a crystalline aluminosilicate zeolite, such as zeolite y, an inorganic oxide matrix and, optionally discrete particles of alumina dispersed in the matrix. The zeolite prior to being composited with the matrix has a unit cell size above about 24.5 angstroms. A cracking process utilizing the catalyst is also provided.

Gladrow, E.M.; Schuette, W.L.; Winter, W.E.

1982-07-13

145

Modified liquid hydrocarbons  

Energy Technology Data Exchange (ETDEWEB)

Modified liquid hydrocarbon fuel, in particular aviation kerosene, having a reduced tendency to undergo mist formation when subjected to shock, contains from 0.05% to 2% of its weight of polymer microgel particles of defined characteristics, the microgel polymer preferably being an addition copolymer of one or more main monomers with a minor proportion, e.g. 0.0005% to 0.1% of the total monomers, of one or more monomers which are multifunctional with respect to the polymerization reaction.

Waite, F. A.

1984-06-05

146

International Organization for Migration  

Science.gov (United States)

The International Organization for Migration (IOM) is an intergovernmental body "committed to the principle that humane and orderly migration benefits migrants and society." IOM currently has 69 member states and 48 observer states worldwide. In addition, numerous international governmental organizations and non-governmental organizations hold observer status with IOM, assisting in the study, development, and enactment of migration policies. The IOM Website offers a wealth of information on the organization and its initiatives. The site posts official IOM news releases and statements and provides access to IOM publications including books, surveys, studies, journals, newsletters, and informational updates. IOM also hosts MIGRATION WEB, a searchable and browseable gateway to a bevy of information resources on the Internet.

147

Migration = cloning; aliasiing  

DEFF Research Database (Denmark)

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

Hüttel, Hans; Kleist, Josva

1999-01-01

148

Synthesis of hydrocarbons from dimethyl ether: selectivities towards light hydrocarbons  

Energy Technology Data Exchange (ETDEWEB)

An efficient hydrocarbon synthesis process has been developed at the University of Akron using dimethyl ether as the starting feedstock. This UA/EPRI`s DTH (Dimethyl Ether to Hydrocarbons) process has significant advantages over its counterpart methanol conversion process in the areas of heat duties, hydrocarbon selectivities, product yield, and reactor size. Lower olefins are the intermediate products in the conversion of dimethyl ether to aromatic hydrocarbons. C{sub 2}-C{sub 4} olefins and paraffins can be selectively produced by varying the operating parameters of the process, viz., temperature, pressure, DME concentration in the feed, space time, catalyst-to-inert packing ratio, etc. The present work focuses on the effect of key process variables on the dimethyl ether conversion to low molecular weight hydrocarbons in a fixed bed microreactor system over ZSM-5 type zeolite catalyst. Experimental results with respect to gaseous hydrocarbon product yields and selectivities have been examined in this study. 5 refs., 5 figs.

Sardesai, A.; Tartamella, T.; Lee, S. [University of Akron, Akron, OH (United States). Dept. of Chemical Engineering

1996-06-01

149

Migration Networks in Senegal  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper investigates the importance and role of migration networks in Senegal using a new nationally representative survey conducted in 2006-2007. Using a sample of 1707 Senegalese households I explore potentially differential effects of networks on international migration depending on their characteristics in terms of composition and destination. Results from logit and multinomial logit regressions show that household networks seem to be destination-specific and have a greater positive in...

2012-01-01

150

Migration and Place Attractiveness  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Niedomysl, Thomas

2006-01-01

151

Essays on international migration  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

2011-01-01

152

Mining Library Migration Graphs  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Software systems intensively depend on external libraries, chosen at conception time. However, relevance of any library irremediably changes during projects and/or library life cycle. As a consequence, projects developers must periodically reconsider the libraries they depend on, and must think about library migration. When they want to migrate their libraries, they then have to identify candidate libraries that offer similar facilities and thus can substitute to each other. They also have to...

Teyton, Ce?dric; Falleri, Jean-re?my; Blanc, Xavier

2012-01-01

153

Migration and Culture  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Epstein, Gil S.; Gang, Ira N.

2010-01-01

154

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

155

Defining lifestyle migration  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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.

Torkington, Kate

2010-01-01

156

Radical scavengers from heavy hydrocarbons  

Energy Technology Data Exchange (ETDEWEB)

The hydrogen-donating properties of some hydrocarbons form the basis for processes such as coal liquefaction and heavy oil upgrading. However, these hydrocarbons have seldom been used for other purposes, because their potential applications have not been well recognized. Research has indicated that these hydrogen-donating hydrocarbons can be used in important reactions as radical scavengers and have properties particular to those of pure hydrocarbons without functional groups containing heteroatoms. Over years of study researchers have found that pure hydrocarbons with radical-scavenging effects nearly as high as those in conventional hindered phenolic antioxidants can be produced from petroleum, and these hydrogen-donating hydrocarbons exhibit such effects even in oxidative atmospheres (i.e., they function as antioxidants). He has also shown that these mixtures have some properties particular to pure hydrocarbons without functional groups containing heteroatoms, and they`ve seen that a mechanism based on the steric effects appears when these hydrocarbons are used in heavy oil hydroprocessing. Hydrogen-donating hydrocarbons should be a viable resource in many applications. In this article, he presents radical-scavenging abilities, characteristics as pure hydrocarbons, and applications on the basis of the studies.

Kubo, Junichi [Nippon Oil Co. Ltd. (Japan)

1996-10-01

157

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

158

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

159

Method of converting heavy hydrocarbon oils into light hydrocarbon oils  

Energy Technology Data Exchange (ETDEWEB)

Heavy hydrocarbon oils are converted into light hydrocarbon oils by two-stage process wherein, in the first stage, a heavy hydrocarbon oil is subjected to thermal cracking conditions and, in the second stage, the product of the thermal cracking is subjected to a hydrotreatment in the presence of a specific catalyst including, as a carrier, a clay mineral consisting mainly of magnesium silicate having a double-chain structure such as sepiolite.

Shiroto, Y.; Hashimoto, H.; Nakata, Sh.

1985-07-23

160

Hydrocarbons exploration in east Siberia southern basins  

Energy Technology Data Exchange (ETDEWEB)

The vast Lena-Tunguska province in the heart of Siberia is among the world's largest and least explored frontier basins. Some encouraging exploration has nevertheless been carried out in the four southern subbasins: PrePatom (PreBaykal) trough, Nepa-Botuobin anticlise, PreSayan-Yenisey basin, and Angara-Lena terrace. Source rocks are essentially Proterozoic, but younger sediments may contribute about 10% of the region's oil potential. Riphean-Cambrian subsalt reservoirs contribute more than 90% of the hydrocarbons discovered, whereas Cambrian salt provides the most common regional seals. The main hydrocarbon later migration occurred in Vendian-Cambrian. Traps include clastic wedging out along favorable structures and carbonate reef-like buildups. Many traps were transformed or destroyed by the late Paleozoic-early Mesozoic volcanic activity, whereas Hercynian overthrust tectonics developed new traps in the PrePatom trough. About 30 discoveries, mainly gas and condensates, have been made in the area, but operations are hampered by poor logistics and limited infrastructure.

Resnick, V.S. (Petroconsultants Inc., Houston, TX (United States))

1991-08-01

 
 
 
 
161

The dynamics of neuronal migration.  

Science.gov (United States)

Proper lamination of the cerebral cortex is precisely orchestrated, especially when neurons migrate from their place of birth to their final destination. The consequences of failure or delay in neuronal migration cause a wide range of disorders, such as lissencephaly, schizophrenia, autism and mental retardation. Neuronal migration is a dynamic process, which requires dynamic remodeling of the cytoskeleton. In this context microtubules and microtubule-related proteins have been suggested to play important roles in the regulation of neuronal migration. Here, we will review the dynamic aspects of neuronal migration and brain development, describe the molecular and cellular mechanisms of neuronal migration and elaborate on neuronal migration diseases. PMID:24243098

Wu, Qian; Liu, Jing; Fang, Ai; Li, Rui; Bai, Ye; Kriegstein, Arnold R; Wang, Xiaoqun

2014-01-01

162

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

163

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

164

Stolt's f-k migration for plane wave ultrasound imaging.  

Science.gov (United States)

Ultrafast ultrasound is an emerging modality that offers new perspectives and opportunities in medical imaging. Plane wave imaging (PWI) allows one to attain very high frame rates by transmission of planar ultrasound wave-fronts. As a plane wave reaches a given scatterer, the latter becomes a secondary source emitting upward spherical waves and creating a diffraction hyperbola in the received RF signals. To produce an image of the scatterers, all the hyperbolas must be migrated back to their apexes. To perform beamforming of plane wave echo RFs and return high-quality images at high frame rates, we propose a new migration method carried out in the frequency-wavenumber (f-k) domain. The f-k migration for PWI has been adapted from the Stolt migration for seismic imaging. This migration technique is based on the exploding reflector model (ERM), which consists in assuming that all the scatterers explode in concert and become acoustic sources. The classical ERM model, however, is not appropriate for PWI. We showed that the ERM can be made suitable for PWI by a spatial transformation of the hyperbolic traces present in the RF data. In vitro experiments were performed to outline the advantages of PWI with Stolt's f-k migration over the conventional delay-and-sum (DAS) approach. The Stolt's f-k migration was also compared with the Fourier-based method developed by J.-Y. Lu. Our findings show that multi-angle compounded f-k migrated images are of quality similar to those obtained with a stateof- the-art dynamic focusing mode. This remained true even with a very small number of steering angles, thus ensuring a highly competitive frame rate. In addition, the new FFT-based f-k migration provides comparable or better contrast-to-noise ratio and lateral resolution than the Lu's and DAS migration schemes. Matlab codes for the Stolt's f-k migration for PWI are provided. PMID:24626107

Garcia, Damien; Le Tarnec, Louis; Muth, Stéphan; Montagnon, Emmanuel; Porée, Jonathan; Cloutier, Guy

2013-09-01

165

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

166

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

1981-09-15

167

Type II Migration is not Locked to Viscous Disk Evolution  

CERN Multimedia

Most standard descriptions of Type II migration state that massive, gap-opening planets must migrate at the viscous drift rate. This assumption is based on the idea that the disk is separated into an inner and outer region and gas is presumed unable to cross the gap. In this work it is numerically demonstrated for a gap-opening Jupiter-mass planet that gas easily crosses the gap on horseshoe orbits, nullifying this necessary premise which would set the migration rate. It is then demonstrated using highly accurate numerical calculations that the actual migration rate is dependent on disk and planet parameters, and can be significantly larger or smaller than the viscous drift rate. In the limiting case of a disk much more massive than the secondary, the migration rate saturates to a constant which is not equal to the viscous rate. In the opposite limit of a low-mass disk, the migration rate decreases linearly with disk mass. Steady-state solutions in this limit show no pile-up outside the secondary's orbit, and...

Duffell, Paul C; MacFadyen, Andrew I; D'Orazio, Daniel J; Farris, Brian D

2014-01-01

168

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

Directory of Open Access Journals (Sweden)

Full Text Available 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-learning process.

Adrienne Kozan Naumescu

2011-03-01

169

Exploration and hydrocarbon potential of interior basins, Alaska  

Energy Technology Data Exchange (ETDEWEB)

During the early 1980s, ARCO Alaska, Inc., conducted an extensive hydrocarbon exploration program in the Alaskan Interior. The study focused on several basinal areas: Middle Tanana, Minchumina, Holitna, Yukon Flats, and Kandik. Other basinal areas (Upper Tanana, Lowre Tanana, and Yukon-Koyukuk) have been reported in the literature to have lower hydrocarbon potential and were not as extensively studied. Several geological and geophysical techniques, including gravity, aeromagnetic, and CDP seismic surveys, were used to establish sediment thickness, basin volume, morphology, and structural style. Analytical data were collected for hydrocarbon source, reservoir potential, and thermal history. Specialized structural and biostratigraphic studies were conducted in some areas. The Middle Tanana and Kandik basins have the highest hydrocarbon potential. A 6-mi wide by 26-mi long half-graben within the Middle Tanana basin contains 20,000 ft of section. The 1984 ARCO Totek Hills 1 well penetrated 3,015 ft of Tertiary (Pliocene to Eocene) section unconformably overlying metamorphic basement. Because it was drilled on the basin flank, the well tested only the uppermost section within the half-graben. Sandstones averaged 17% porosity and 11 md permeability. Claystones containing type II kerogen showed good oil-generating potential (pyrolysis S1 + S2 values average 17 mg/g). The Kandik basin contains excellent source rocks in the Triassic Glen Shale (S2 averaging 16 mg/g). Hydrocarbon thermal maturation changes from immature to postmature in a stepwise fashion across thrust faults from southeast to northwest. Solid residue of migrated hydrocarbons occurs in formations of Devonian, Pennsylvanian, Permian, and Triasic age.

Grether, W.J.; Morgan, K.A.

1988-01-01

170

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

171

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...

2006-01-01

172

Hydrocarbon conversion catalysts  

Energy Technology Data Exchange (ETDEWEB)

This patent describes a process for hydrocracking hydrocarbon oils into products of lower average molecular weight and lower average boiling point. It comprises contacting a hydrocarbon oil at a temperature between 250{sup 0}C and 500{sup 0}C and a pressure up to 300 bar in the presence of hydrogen with a catalyst consisting essentially of a Y zeolite modified to have a unit cell size below 24.35A, a water absorption capacity (at 25{sup 0}C and a rho/rho/sub o/ value of 0.2) of at least 8% by weight of the zeolite and a pore volume of at least 0.25 ml/g wherein between 10% and 60% of the total pore volume is made up of pores having a diameter of at least 8 nm; an alumina binder and at least one hydrogenation component selected from the group consisting of a Group VI metal, a Group VIII metal and mixtures thereof.

Hoek, A.; Huizinga, T.; Maxwell, I.E.

1989-08-15

173

Unix Application Migration Guide  

CERN Multimedia

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

Microsoft. Redmond

2003-01-01

174

[Migration and health].  

Science.gov (United States)

In the last decades of this century we are witnesses of frequent crises in different parts of the world produced by internal disturbance and wars. These crises, together with natural disasters, poverty and hunger, follow the history of mankind often forcing huge population groups to leave their homes. The harmful health consequences are among negative effects of migrations. While stable populations have well-tried routines for maintaining health, migrations mean abandoning such support systems. The increased exposure to harmful factors contributes more to the bad health condition of the migrant population. Setting of newcomers and local people together in the same homes, reduction in food and heating resources, drug shortage as well as importation of new infectious agents, may also endanger health of the native population. These observations have also been confirmed by Yugoslav experience. Depending on the fact whether a migration is elemental or organized i.e. dependent on its place in the large scale between these two extreme endpoints, the size of risk is also dependent on the consequences and degree of their difficulty. Mass health disturbances occur during migrations of the population from war regions, migrations from areas of natural disasters, mass pilgrimage, migrations of seasonal workers and migrations of armies during wars. However, even in these difficult times and conditions, a good organization can contribute to the mitigation of harmful consequences caused by these migrations. For instance, in 1942 there was an epidemic of typhus fever in Bosnia when many refugees crossed the Drina river on the way to Serbia escaping from Ustasha terrorism. At the Serbian side there were checkpoints where the refugees could taka a bath and where their laundry and clothing were depediculated with dry air, and after a two-week quarantine they could continue to Serbian provinces without making new foci of typhus fever. The most vulnerable and numerous group of refugees is usually composed of women, children and old persons. One of the largest migrations took place over the period from 1991 to 1995, when about 1,500,000 people left the war areas of the former Yugoslavia, Bosnia-Herzegovina and Croatia. Of that number, about 700.000 refugees came to Yugoslavia. In August 1995 during an unprecedented exile from the Kninska krajina region (Croatia) over 200,000 people left their homes. During the arrival of refugees and expelled persons health teams offered first aid to these unlucky persons at reception points: drinking water, food, emergency care and indispensable clothing. The next step in their task was to move refugees into families i.e. into collective camps and centres. As in similar situations, this migration had also its negative effects on health of the refugees. At this time, however, the situation was aggravated by international economic sanctions imposed to Yugoslavia although Yugoslavia has accepted and received more refugees than all European countries together. In 1992 a special refugees Law was promulgated in Yugoslavia. In this Law, among other things, it was stated that "the organized reception, temporary lodging, nutrition, appropriate health care, material and other sort of help" will be secured to refugees. The increased infant mortality rate in Yugoslavia may be ascribed to migrations. After several years of decrease it was in constant rise over the period from 1991 to 1995 (Table 1). Disturbed mental balance, loosing of ethic norms, feeling of hopelessness and despair, and underestimation of the risk of infections among refugees, contributed to the rise of promiscuity and increase in sexually transmitted diseases. Thus, the number of registered cases of symphills in the period 1991-1995 was six times greater than in previous years. The number of gonorrhea cases was twice greater in this period than before that time. At the same time, it should be emphasized that the number of recorded cases was smaller than it w PMID:9304230

Litvinjenko, S

1997-01-01

175

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

176

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.

2010-03-01

177

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

Energy Technology Data Exchange (ETDEWEB)

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 [Department of Energy, Royal Institute of Technology, Stockholm, 10044 (Sweden); Kolesnikov, A [Physical Chemistry Department, Moscow State Academy of Fine Chemical Technology, Vernadsky ave.86, Moscow, 119571 (Russian Federation); Dyuzheva, T; Brazhkin, V, E-mail: vladimir@flotten.s [Institute of High Pressure Physics, Troitsk, 142190 (Russian Federation)

2010-03-01

178

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

179

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)

1986-01-01

180

International Migration of Couples  

DEFF Research Database (Denmark)

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

Munk, Martin D.; Junge, Martin

 
 
 
 
181

Radionuclide migration in groundwater  

International Nuclear Information System (INIS)

The migration rates and mechanisms of a large suite of radionuclides in groundwater created by the disposal of low-level aqueous effluents from the Hanford N-Reactor are being characterized. These studies are developing information which can be applied to understanding and predicting the movement of radionuclides in shallow-land burial sites which may become saturated with groundwater. The movement of the various radionuclides in groundwater at the N-Reactor disposal site is being investigated as a function of their physicochemical forms. Those radionuclides most readily migrating include tritium and anionic species of "1"3"1 "1"3"3I, "6"0Co, "1"0"3 "1"0"6Ru, "1"2"2 "1"2"4 "1"2"5Sb, /sup 99m,99/Tc, and "9"9Mo. Also migrating are traces of "2"3"8 "2"3"9 "2"4"0Pu in an oxidized (V or VI) anionic form(s). Various parameters affecting the physicochemical speciation of the radionuclides, including the major and trace ions, organic constitutents, colloidal materials, and soil chemistry are being characterized to determine their relative roles in the migration processes. the data generated in this study will be extremely valuable in formulating guidelines for the operation of existing low-level waste disposal sites, in determining what long-term surveillance and maintenance needs will be required, and in determining essential requirements for remedial action. 4 tables

1982-10-01

182

Practical Data Migration  

CERN Multimedia

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

183

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

184

Development of isotope techniques for hydrocarbon exploration  

International Nuclear Information System (INIS)

A gas preparation line has been constructed to measure D/H- in addition to 13C/12C-ratios on minute quantities of methane (down to 50 ?l CH4) from well samples. The gas oxidation line was tested with samples from 3 wells from the S. German Molasse and the Rhine Valley. Hydrogen isotopes distinguish between gases of thermogenic origin and those from the different methanogenic pathways. The combination of carbon and hydrogen isotopes is useful to classify gases affected by secondary processes such as oxidation or mixing. The maturity of the source rocks generating the gases can also be estimated using carbon and hydrogen isotopes. A previously unknown biogenic methane group has been identified which is depleted strongly in both deuterium and carbon-13. Additionally, a new genetic gas type was observed with dD -40 per mille, and with higher hydrocarbons present. (orig.)

1986-01-01

185

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

1979-01-01

186

Nitrated polycyclic aromatic hydrocarbons  

Energy Technology Data Exchange (ETDEWEB)

As stated in the preface, this multi-author book was written in order to cover the more important aspects of the analytical, organic, and environmental chemistries of nitro-PAH (nitrated polycyclic aromatic hydrocarbons). Thus although this book is part of a series on chromatographic methods, the scope of this particular volume is considerably more broad. This book contains seven chapters and one appendix. Four chapters of this book are devoted to the analytical aspects of nitro-PAH, with chapters on gas chromatography, chromatographic detectors, mass spectrometry, and liquid chromatography. The three remaining chapters cover the synthesis of nitro-PAH, their mutagenic and carcinogenic properties, and the sampling and atmospheric chemistry of particles containing nitro-PAH. The thirty-page appendix consists of two tables with structural, chemical, and physical properties for these compounds, with references to the original literature where appropriate.

White, C.M. (ed.)

1985-01-01

187

TOWARD MIGRATION TRANSITION IN ROMANIA  

Directory of Open Access Journals (Sweden)

Full Text Available Most studies regarding the contribution of migration to development are limited to an isolated analysis of the economic effects of migration. But the migration process is in turn influenced by other processes. So a wider framework including migration and other processes of development would be more appropriate. The experience of South European and East Asian countries have shown us that, during development, countries can change their migration profile from emigration to immigration. The present paper shows the stages of the migration transition experienced by these countries trying to match them with Romania’s experience. So, focusing on the case of Romania, this paper examines the evolution of international migration starting with 1990, in the context of the broader transition process, offering prospects regarding a possible migration transition in this case as well.

Cristian Incaltarau

2012-12-01

188

The mechanism of methanol to hydrocarbon catalysis.  

Science.gov (United States)

The process of converting methanol to hydrocarbons on the aluminosilicate zeolite HZSM-5 was originally developed as a route from natural gas to synthetic gasoline. Using other microporous catalysts that are selective for light olefins, methanol-to-olefin (MTO) catalysis may soon become central to the conversion of natural gas to polyolefins. The mechanism of methanol conversion proved to be an intellectually challenging problem; 25 years of fundamental study produced at least 20 distinct mechanisms, but most did not account for either the primary products or a kinetic induction period. Recent experimental and theoretical work has firmly established that methanol and dimethyl ether react on cyclic organic species contained in the cages or channels of the inorganic host. These organic reaction centers act as scaffolds for the assembly of light olefins so as to avoid the high high-energy intermediates required by all "direct" mechanisms. The rate of formation of the initial reaction centers, and hence the duration of the kinetic induction period, can be governed by impurity species. Secondary reactions of primary olefin products strongly reflect the topology and acid strength of the microporous catalyst. Reaction centers form continuously through some secondary pathways, and they age into polycyclic aromatic hydrocarbons, eventually deactivating the catalyst. It proves useful to consider each cage (or channel) with its included organic and inorganic species as a supramolecule that can react to form various species. This view allows us to identify structure-activity and structure selectivity relationships and to modify the catalyst with degrees of freedom that are more reminiscent of homogeneous catalysis than heterogeneous catalysis. PMID:12755641

Haw, James F; Song, Weiguo; Marcus, David M; Nicholas, John B

2003-05-01

189

Gender and Migration from Albania  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This article examines the dynamics and causes of the shift in the gender composition of migration, and more particularly, in women’s access to migration opportunities and decision-making. Our analysis focuses on Albania, a natural laboratory for studying international migration where out-migration was essentially nonexistent from the end of World War II to the end of the 1980s. Interest in the Albanian case is heightened because of the complex layers of inequality existing at the time when ...

2010-01-01

190

Complexities of migration : picaresque drawing  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This article commences with a consideration of migration as an experience, an idea, a theme and a practice. It considers the antipodes as a focus of migration and the central role of migration in the antipodean imaginary. The writing then presents some contemporary drawings in the antipodes which make manifest the complexities of being unsettled and thus marginalised in one way or another. It argues that drawing is par excellence the material practice of migration as it is itself unsettled, u...

Schmidt, Leoni

2007-01-01

191

European Integration and Labour Migration  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 m...

Julda Kielyte

2010-01-01

192

The effect of overpressure on hydrocarbon trapping in the chalk of the greater Ekofisk area (Norway)  

Energy Technology Data Exchange (ETDEWEB)

The Chalk of the Greater Ekofisk Area is a relatively closed system for fluid movements and it is interpreted that large pressure cells have developed, all characterised by their own pressure regime, fluid type and trapping potential. In such a system where overpressures. mainly generated by compaction, reach very high values, we try to understand what are the implications on the trapping mechanisms and hydrocarbon distribution. We conclude that, today, the aquifer is near static and that there is no significant regional hydrodynamic flow. During the Tertiary period the Chalk system has evolved from hydrostatic conditions to high overpressure conditions. This transformation had a primary control on chalk permeability and fluid movements. A significant lateral fluid transmissibility within the Chalk existed during the main phase of oil migration (Miocene) because at that time, the Chalk was more permeable and more homogeneous than today. The pressure distribution observed today corresponds to a closed system where the lateral fluid flow is restricted, whilst the pressure is controlled by the seal capacity. The hydrocarbon distribution in the Greater Ekofisk Area is the result of a dynamic process dependent on burial, hydrocarbon generation and migration, diagenesis and seal integrity. This process controlled both chalk porosity and hydrocarbon trapping. Oil accumulations in the area are complex and are dependent more on the complexity of the reservoirs in terms of geometry, porosity and capillary pressure, all inherited since Miocene time, rather than on the present-day migration system. (author)

Caillet, G. [Elf Exploration Production, Centre Scientifique et Technique Jean Feger, 64 - Pau (France); Bramwell, N. [Phillips Petroleum Norway, Tananger (Norway); Meciani, L. [Agip, Milano (Italy)

1999-04-01

193

Red Sea hydrocarbon system focus on the source rock and hydrocarbon generation  

Energy Technology Data Exchange (ETDEWEB)

Potential source rocks were identified in the Egyptian Red Sea wells. These are Middle-Late Miocene and/or Early Miocene. The former contains up to 7.0% total organic carbon (TOC) and kerogen type is I and II. TOC values in the later up to 1.0% and kerogen type is II-III. Source rocks maturity, determined mainly by vitrinite reflectance and Tmax, reveals that the studied sequences have a maturity range from marginally mature to mature and over mature only were they are affected by abrupt change associated with thermal anomaly. Vitrinite reflectance pilots, revealed two thermal events affecting the maturity. The first event is Pre-intra-Rudeis unconformity, with a gradient of 0.26 to 0.66 % R[sub o] per 1,000 feet of burial. The later event occurred at the Post intra-Rudeis unconformity with a gradient of 0.02 to 0.06 % Ro increase per 1,000 feet. As a result of tectonism and the variation in the temperature gradients, the present top oil window varies in depth from 1540 to 3505 m and the hydrocarbon generation modeling suggests that, the generation may have occured during Late Miocene time and is still going on. Rock-Eval analysis indicates that there is ample evidence of hydrocarbon migration in the region.

Tammam, M.T. (Egyptian General Petroleum Corp., Cairo (Egypt))

1996-01-01

194

Red Sea hydrocarbon system focus on the source rock and hydrocarbon generation  

Energy Technology Data Exchange (ETDEWEB)

Potential source rocks were identified in the Egyptian Red Sea wells. These are Middle-Late Miocene and/or Early Miocene. The former contains up to 7.0% total organic carbon (TOC) and kerogen type is I and II. TOC values in the later up to 1.0% and kerogen type is II-III. Source rocks maturity, determined mainly by vitrinite reflectance and Tmax, reveals that the studied sequences have a maturity range from marginally mature to mature and over mature only were they are affected by abrupt change associated with thermal anomaly. Vitrinite reflectance pilots, revealed two thermal events affecting the maturity. The first event is Pre-intra-Rudeis unconformity, with a gradient of 0.26 to 0.66 % R{sub o} per 1,000 feet of burial. The later event occurred at the Post intra-Rudeis unconformity with a gradient of 0.02 to 0.06 % Ro increase per 1,000 feet. As a result of tectonism and the variation in the temperature gradients, the present top oil window varies in depth from 1540 to 3505 m and the hydrocarbon generation modeling suggests that, the generation may have occured during Late Miocene time and is still going on. Rock-Eval analysis indicates that there is ample evidence of hydrocarbon migration in the region.

Tammam, M.T. [Egyptian General Petroleum Corp., Cairo (Egypt)

1996-12-31

195

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...

196

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 sulfate replenishment process to identify the relationship between sulfate reduction and hydrocarbon degradation, and to test the supplementation of sulfate. 18 refs., 10 figs

2007-10-21

197

Gender and migration from Albania.  

Science.gov (United States)

This article examines the dynamics and causes of the shift in the gender composition of migration, and more particularly, in women's access to migration opportunities and decision-making. Our analysis focuses on Albania, a natural laboratory for studying international migration where out-migration was essentially nonexistent from the end of World War II to the end of the 1980s. Interest in the Albanian case is heightened because of the complex layers of inequality existing at the time when migration began: relatively low levels of inequality within the labor market and educational system-a product of the Communist era-while household relations remained heavily steeped in tradition and patriarchy. We use micro-level data from the Albania 2005 Living Standards Measurement Study, including migration histories for family members since migration began. Based on discrete-time hazard models, the analysis shows a dramatic increase in male migration and a gradual and uneven expansion of the female proportion of this international migration. Female migration, which is shown to be strongly associated with education, wealth, and social capital, appears responsive to economic incentives and constraints. Using information on the dependency of female migration to the household demographic structure as well as the sensitivity of female migration to household-level shocks, we show how household-level constraints and incentives affect male and female migration differently. Throughout this period, however, women's migration behavior appears more directly aligned with household-level factors, and there is little evidence to suggest that increased female migration signals rising behavioral independence among Albanian women. PMID:21308565

Stecklov, Guy; Carletto, Calogero; Azzarri, Carlo; Davis, Benjamin

2010-11-01

198

Dispersal and migration  

Directory of Open Access Journals (Sweden)

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

Bairlein, F.

2004-01-01

199

Conflict and forced migration  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Dans cette thèse, je cherche à améliorer notre compréhension de deux phénomènes, à savoir l’émergence de conflits armés et la migration forcée. Le premier chapitre décrit la logique de recherche économique suivie tout au long de la thèse. Dans le second chapitre, j’étudie le rôle des inégalités de revenus dans les conflits armés ayant eu lieu au sud du Mexique. Les inégalités de revenus au niveau municipal expliquent de manière significative la motivation des individu...

2010-01-01

200

Functorial Data Migration  

CERN Document Server

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

Spivak, David I

2010-01-01

 
 
 
 
201

Wetlands and Bird Migration  

Science.gov (United States)

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

202

Essays on migration  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

2009-01-01

203

Customer channel migration  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Customer Channel Migration deals with the active management of a customer's channel usage behavior with the aim to increase her profitability and lifetime. Hence, the dissertation answers two distict questions: on one hand, it investigates the impact of channel use on a customer's profitability and lifetime. On the other hand, it is researched how a customer's channel usage behavior can be influenced and managed. The cumulative dissertation consists of five articles: the first article describ...

Bo?hm, Martin

2006-01-01

204

Grain boundary migration  

International Nuclear Information System (INIS)

Well-established aspects of grain-boundary migration are first briefly reviewed (influences of driving force, temperature, orientation and foreign atoms). Recent developments of the experimental methods and results are then examined, by considering the various driving of resistive forces acting on grain boundaries. Finally, the evolution in the theoretical models of grain-boundary motion is described, on the one hand for ideally pure metals and, on the other hand, in the presence of solute impurity atoms

1975-06-16

205

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

206

Primary and Secondary Sources  

Science.gov (United States)

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

Bates, Albion M.

2010-01-23

207

Secondary Predication in Russian  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The paper makes two contributions to semantic typology of secondary predicates. It provides an explanation of the fact that Russian has no resultative secondary predicates, relating this explanation to the interpretation of secondary predicates in English. And it relates depictive secondary predicates in Russian, which usually occur in the instrumental case, to other uses of the instrumental case in Russian, establishing here, too, a difference to English concerning the scope of the secondary...

Strigin, Anatoli; Demjjanow, Assinja

2001-01-01

208

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.

209

Hydrocarbon deasphalting via solvent extraction  

Energy Technology Data Exchange (ETDEWEB)

Maximum removal of asphaltic material, including high molecular weight metallic contaminants, from a hydrocarbonaceous charge stock is achieved through the utilization of a solvent extraction zone provided with direct heating facilities in an upper portion thereof. A portion of the solvent-rich hydrocarbon phase is withdrawn from the extraction zone, increased in temperature and introduced into an asphalt settling zone. The separated solvent/hydrocarbon stream, substantially asphalt-free, is reintroduced into the extraction zone at the higher temperature.

Uitti, K.D.; Bunas, B.I.

1976-08-03

210

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

211

Electrostatically atomised hydrocarbon sprays  

Energy Technology Data Exchange (ETDEWEB)

A burner using an electrostatic method to produce and control a fuel spray is investigated for non-burning sprays. The burner has a charge injection nozzle and the liquid flow rate and charge injection rate are varied using hydrocarbon liquids of differing viscosities, surface tensions and electrical conductivities (kerosene, white spirit and diesel oil). Droplet size distributions are measured and it is shown how the dropsize, spray pattern, breakup mechanism and breakup length depend on the above variables, and in particular on the specific charge achieved in the spray. The data are valuable for validating two computer models under development. One predicts the electric field and flow field inside the nozzle as a function of emitter potential, geometry and flow rate. The other predicts the effect of charge on spray dispersion, with a view to optimizing spray combustion. It is shown that electrostatic disruptive forces can be used to atomize oils at flow rates commensurate with practical combustion systems and that the charge injection technique is particularly suitable for highly resistive liquids. Possible limitations requiring further research include the need to control the wide spray angle, which may provide fuel-air mixtures too lean near the nozzle, and the need to design for maximum charge injection rate, which is thought to be limited by corona breakdown in the gas near the nozzle orifice. 30 refs., 15 figs., 1 tab.

Yule, A.J.; Shrimpton, J.S.; Watkins, A.P.; Balachandran, W.; Hu, D. [UMIST, Manchester (United Kingdom). Thermofluids Division, Dept. of Mechanical Engineering

1995-07-01

212

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

213

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

1981-01-01

214

International Migration Diversification: A New Perspective to Migration Management  

Directory of Open Access Journals (Sweden)

Full Text Available Diversifying migration for development is an option that much has been discussed and yet little has been done in sending countries. The potential of international migration being harnessed for economic and social development have gained significant importance. Some initiatives have been discussed and launched to manage international migration. Some of these efforts are aimed at addressing the issue of containing the outflow and encouraging return of migrants to help with nation building. But these programmes are not adequate, and therefore more needs to be done. This study aims to review the international migration literature to examine the trend of migration and advocate for its diversification for development in sending countries. Some countries have courted the idea of diversifying migration but none have taken on the challenge. This study provides a precursor for policy makers to better understand international migration trends, options and strategies that can lead to diversification. The way forward for diversifying is a call for empirical studies to comparatively weight the options and develop short, medium and long term strategies. The question is whether policy makers in sub-Saharan Africa will take on the challenge to manage and transform international migration especially of the highly skilled. The paper calls for a different perspective in managing migration and contributes to the literature on international migration diversification for sending countries.

Cynthia A. Bulley

2014-04-01

215

Study of liquid hydrocarbons subjected to ionizing radiations  

International Nuclear Information System (INIS)

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

1977-01-01

216

Japanese migration in contemporary Japan: economic segmentation and interprefectural migration.  

Science.gov (United States)

This paper examines the economic segmentation model in explaining 1985-86 Japanese interregional migration. The analysis takes advantage of statistical graphic techniques to illustrate the following substantive issues of interregional migration: (1) to examine whether economic segmentation significantly influences Japanese regional migration and (2) to explain socioeconomic characteristics of prefectures for both in- and out-migration. Analytic techniques include a latent structural equation (LISREL) methodology and statistical residual mapping. The residual dispersion patterns, for instance, suggest the extent to which socioeconomic and geopolitical variables explain migration differences by showing unique clusters of unexplained residuals. The analysis further points out that extraneous factors such as high residential land values, significant commuting populations, and regional-specific cultures and traditions need to be incorporated in the economic segmentation model in order to assess the extent of the model's reliability in explaining the pattern of interprefectural migration. PMID:1749966

Fukurai, H

1991-01-01

217

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

218

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 m"3/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 m"3/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)

1983-01-01

219

ILO - International Migration Programme.  

Science.gov (United States)

In a wide International Context characterised not only by the economical development but also by the social, cultural, political and individual development, we witness more and more to a exchange between the developed and the developing countries, which can be translated especially in the migration of the work force. In theory, all countries are either countries of origin either countries of transit or destination, and they are all responsible for the rights of migrant workers by promoting the rights, by monitoring and by preventing the abusive conditions. The process of migration of the workforce can be divided into three stages: the first coincides with the period prior to departure, the second is represented by the aftermath of the departure and the period of stay in the country of destination, the third stage corresponds to the return in the country of origin. The workers must be protected throughout this process by the international organizations that perform the catalytic role of communication and exchange between countries, for the only purpose of protecting the rights of immigrant and/or immigrants workers. The responsibility for the protection of workers is divided among the various players in the International Labour Organisation. Every country has to apply measures according to the international standards regarding workers' rights, standards that guide the various countries in the formulation and implementation of their policies and legislation. These standards are suggested by International Conventions, the ILO Conventions and other international instruments such as the human rights instrument. There has been a big step forward once the ILO Fundamental Conventions and Conventions on Migrant Workers where implemented and this implementation represented the use of the Guidelines "ILO Multilateral Framework on Labour Migration". PMID:22073693

Boudraa, Miriam

2011-01-01

220

Experimental glomerulonephritis induced by hydrocarbon exposure: A systematic review  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Much epidemiological evidence suggests that hydrocarbon exposure may induce glomerulonephritis and worsen its course in many patients. The mechanisms are unknown, however, no specific microscopic pattern has been identified, and it has also been argued that hydrocarbon exposure causes tubular damage mainly. Studying experimental animals may best answer these questions, and as no systematic review of glomerulonephritis produced experimentally by hydrocarbon exposure has been performed previously, I found it relevant to search for and analyse such studies. Methods Animal experiments having mimicked human glomerulonephritis by hydrocarbon exposure were sought on Medline and Toxnet Results Twenty-six experiments using thirteen different hydrocarbons were identified. Several human subtypes were observed including IgA nephritis, mesangial, proliferative and extracapillary glomerulonephritis, focal and focal-segmental sclerosis, minimal change nephropathy, anti-GBM and anti-TBM nephritis, and glomerulonephritis associated with peiarteritis nodosa. Glomerular proteinuria was seen in 10/12 experiments that included urine analyses, and renal failure in 5/8 experiments that included measurements of glomerular function. All experiments resulted in various degrees of tubular damage as well. In most studies, where the animals were examined at different times during or after the exposure, the renal microscopic and functional changes were seen immediately, whereas deposits of complement and immunoglobulins appeared late in the course, if at all. Conclusion These experiments are in accord with epidemiological evidence that hydrocarbon exposure may cause glomerulonephritis and worsen renal function. Probable mechanisms include an induction of autologous antibodies and a disturbance of normal immunological functions. Also, tubular damage may increase postglomerular resistance, resulting in a glomerular deposition of macromolecules. In most models a causal role of glomerular immune complex formation was unlikely, but may rather have been a secondary phenomenon. As most glomerulonephritis subgroups were seen and as some of the hydrocarbons produced more than one subgroup, the microscopic findings in a patient cannot be used as a clue to the causation of his disease. By the same reason, the lack of a specific histological pattern in patients with glomerulonephritis assumed to have been caused by hydrocarbon exposure is not contradictive.

Ravnskov Uffe

2005-12-01

 
 
 
 
221

Polycyclic Aromatic Hydrocarbons  

Science.gov (United States)

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

Salama, Farid

2010-01-01

222

Issues of Labor Migration  

Directory of Open Access Journals (Sweden)

Full Text Available Factors of production are resources available, attracted and utilized in economic activity, namely in the production of material goods and services. Productive resources such as land, minerals, construction, machinery and equipment manufacturing, energy, water, knowledge and experience, information, resources are crucial for a country’s economy. In this context, taking account of current policy and socio - political - ecomonic, both globally and nationally, the country’s European Union integration perspective, this paper aims to bring to the fore the issue of labor migration.

Liliana Gheorghe

2010-12-01

223

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...

2010-01-01

224

Residential Mobility and Migration  

Science.gov (United States)

This activity is used in an Introduction to Populations Issues class for undergraduate students. This activity looks at education, marital status, age and race to explore migration trends in the United States. This activity uses eight customized data sets made from the 1990 census. It guides students through data manipulation using WebCHIP software found at DataCounts!. To open WebCHIP with the dataset for the activity, please see instructions and links in the exercise documents under teaching materials. For more information on how to use WebCHIP, see the How To section on DataCounts!

Crowder, Kyle

225

[Obesity, migration and adolescence].  

Science.gov (United States)

Weight management interventions during adolescence are challenging. Migration adds complexity to this problem, making migrant families more vulnerable. Teenagers confront families to new values transmitted by the host society: opulence, junk food, video games. Obesity should not be seen as a single issue of calories-excess, but must be considered as being part of a larger problem, which takes into account the context of the familial and societal life of the migrants. The caregivers must have an overall view of the situation to provide appropriate approaches to weight management. PMID:22787729

Chamay-Weber, Catherine; Shehu-Brovina, Shqipe; Narring, Françoise

2012-06-13

226

Metal-hydrogen bridge bonding of hydrocarbons on metal surfaces  

Energy Technology Data Exchange (ETDEWEB)

Molecular orbital studies implicate multicenter metal-hydrogen-carbon interactions as contributors to the bonding of chemisorbed hydrocarbons on clean metal surfaces. The most stable geometries appear to be those that achieve the maximum multicenter bonding to the coordinately unsaturated metal atoms in the vicinity of the anchoring metal-carbon interaction. Energy differences between possible surface sites are of the same magnitude as stabilization energies for three-center bonding of hydrogen atoms to the metal surface. Accordingly, secondary interactions of hydrogen with neighboring metal atoms may be significant determining factors in surface structures. The model predictions are compared with known structures and are used to propose a mechanism for hydrocarbon reactions on metal surfaces. These metal-hydrogen-carbon interactions are presumed to be intermediate points or states in C-H bond-breaking processes.

Gavin, R.M. Jr. (Haverford College, PA); Reutt, J.; Muetterties, E.L.

1981-07-01

227

Hydrocarbon exploration risk evaluation through uncertainty and sensitivity analyses techniques  

International Nuclear Information System (INIS)

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

2004-03-08

228

Hydrocarbon exploration risk evaluation through uncertainty and sensitivity analyses techniques  

Energy Technology Data Exchange (ETDEWEB)

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

Ruffo, Paolo [ENI-E and P Division, Via Emilia 1, 20097 S. Donato Mil.se (MI) (Italy)]. E-mail: paolo.ruffo@agip.it; Bazzana, Livia [ENI-E and P Division, Via Emilia 1, 20097 S. Donato Mil.se (MI) (Italy)]. E-mail: livia.bazzana@agip.it; Consonni, Alberto [ENI-E and P Division, Via Emilia 1, 20097 S. Donato Mil.se (MI) (Italy)]. E-mail: alberto.consonni@agip.it; Corradi, Anna [ENI-E and P Division, Via Emilia 1, 20097 S. Donato Mil.se (MI) (Italy)]. E-mail: anna.corradi@agip.it; Saltelli, Andrea [JRC-IPSC , 21020 Ispra (VA) (Italy)]. E-mail: andrea.saltelli@jrc.it; Tarantola, Stefano [JRC-IPSC , 21020 Ispra (VA) (Italy)]. E-mail: stefano.tarantola@jrc.it

2006-10-15

229

Hydrocarbon entrapment in Trenton of southern Ontario  

Energy Technology Data Exchange (ETDEWEB)

Middle Ordovician Trenton strata in southern Ontario are represented by a generally transgressive sequence that reflects a wide spectrum of carbonate environments from tidal flat, through lagoon and shoal, into deeper shelf carbonates. Virtually all Ordovician production in Ontario is associated with structural deformation related to rejuvenation of a Precambrian fracture framework triggered by orogenic events in the nearby Appalachian orogene. The reservoirs are characterized by the replacement of original bioclastic limestone beds by more or less discontinuous lenses of fine to medium-grained, light to medium-brown crystalline dolostone. Pools generally are linear, following the trend of the associated fracture. Six of the 18 known Ordovician pools in Ontario are located in Essex County. A detailed study of the geology and reservoirs confirmed the close association of fracturing, dolomitization, and hydrocarbon entrapment. Representative samples of well cuttings from 20 wells were analyzed by XRD (x-ray defraction) to determine calcite-dolomite ratios. As expected, low ratios were present in the producing reservoirs. Partially dolomitized zones were revealed in wells in close proximity to fractures. Formation water originating in the underlying Cambrian sandstones was probably the main dolomitizing agent as it migrated up through the fracture. Dolomitization enhanced already existing porosity within the bioclastic zones.

Trevail, R.A.

1984-12-01

230

Hyperaldosteronism - primary and secondary  

Science.gov (United States)

Primary and secondary hyperaldosteronism are conditions in which the adrenal gland releases too much of the hormone ... People with primary hyperaldosteronism have a problem with the adrenal gland that causes it to release too much aldosterone. In secondary ...

231

Bacterial migration along solid surfaces.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

An in vitro system was developed to study the migration of uropathogenic Escherichia coli strains. In this system an aqueous agar gel is placed against a solid surface, allowing the bacteria to migrate along the gel/solid surface interface. Bacterial strains as well as solid surfaces were characterized by means of water contact angle and zeta potential measurements. When glass was used as the solid surface, significantly different migration times for the strains investigated were observed. Re...

1992-01-01

232

Changing patterns of Ghanean Migration  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Migration has been part of people’s experience in many parts of Africa throughout history (De Bruin et al. 2001) and Ghana is no exception. Migration flows were typically regional due to commerce, forced labor and circulatory nomadic routes. Over the last decades however, migration patterns extended geographically with larger shares of migrants moving to Europe and North America. Even within these regions, African migrant flows have been diversifying (Grillo & Mazzucato 2008). Yet little co...

2013-01-01

233

Disks, Extrasolar Planets and Migration  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We review results about protoplanetary disk models, protoplanet migration and formation of giant planets with migrating cores. We first model the protoplanetary nebula as an \\alpha-accretion disk and present steady state calculations for different values of \\alpha and gas accretion rate through the disk. We then review the current theories of protoplanet migration in the context of these models, focusing on the gaseous disk-protoplanet tidal interaction. According to these t...

Terquem, C.; Papaloizou, J.; Nelson, R.

1999-01-01

234

Public goods' attractiveness and migrations  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The aim of this paper is to develop a dynamic model of migrations, in which migration is driven by size asymmetries between countries and by the relative preferences of consumers between private consumption and consumption of public goods. The dynamic tra jectories heavily depend on the degree of attractiveness for public goods We show that monotone migrations require sufficiently strong preferences for public goods, and can only be sustained from the small to the large countries. We identify...

Gabszewicz, Jean; Gvetadze, Salome; Laussel, Didier; Pieretti, Patrice

2008-01-01

235

Families, children, migration and AIDS  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Haour-knipe, Mary

2009-01-01

236

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.

Nigel, Harris.

237

Evolved gas analysis of secondary organic aerosols  

Energy Technology Data Exchange (ETDEWEB)

Secondary organic aerosols have been characterized by evolved gas analysis (EGA). Hydrocarbons selected as aerosol precursors were representative of anthropogenic emissions (cyclohexene, cyclopentene, 1-decene and 1-dodecene, n-dodecane, o-xylene, and 1,3,5-trimethylbenzene) and of biogenic emissions (the terpenes [alpha]-pinene, [beta]-pinene and d-limonene and the sesquiterpene trans-caryophyllene). Also analyzed by EGA were samples of secondary, primary (highway tunnel), and ambient (urban) aerosols before and after exposure to ozone and other photochemical oxidants. The major features of the EGA thermograms (amount of CO[sub 2] evolved as a function of temperature) are described. The usefulness and limitations of EGA data for source apportionment of atmospheric particulate carbon are briefly discussed. 28 refs., 7 figs., 4 tabs.

Grosjean, D.; Williams, E.L. II; Grosjean, E. (DGA, Inc., Ventura, CA (United States)); Novakov, T. (Lawrence Berkeley Lab., CA (United States))

1994-11-01

238

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

239

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

240

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

 
 
 
 
241

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)

2001-03-01

242

Les questions de migrations internationales (Questions of International Migrations).  

Science.gov (United States)

Education about international migration should (1) utilize a framework of historical evolution; (2) stress the growing interdependence of nations; (3) emphasize universal moral values and the role of the individual in human rights; and (4) consider the complementary or competing portraits of international migration presented by the media. (DMM)

Samman, Mouna Liliane

1993-01-01

243

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

244

REDUCTION OF VITELLOGENIN SYNTHESIS BY AN ARYL HYDROCARBON RECEPTOR AGONIST IN THE WHITE STURGEON (ACIPENSER TRANSMONTAMUS)  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Migrating white sturgeon (Acipenser transmontamus) may be subject to agricultural, municipal, and industrial wastewater effluents that likely contain different classes of endocrine-disrupting contaminants. Concern is mounting about the negative effects of environmental estrogens on fish reproduction; however, in environmental mixtures, the affects from estrogenic compounds may be suppressed by aryl hydrocarbon receptor (AhR) ligands. Indeed, reductions in 17?-estradiol–induced (0.01 and 1 ...

Palumbo, Amanda J.; Denison, Michael S.; Doroshov, Serge I.; Tjeerdema, Ronald S.

2009-01-01

245

Geology, source rocks and hydrocarbon generation in the Clarence-Moreton Basin. [Australia  

Energy Technology Data Exchange (ETDEWEB)

The geology and exploration history of the Triassic-Cretaceous Clarence-Moreton Basin are reviewed. Consideration of new geochemical data ('Rock-Eval', vitrinite reflectance, gas chromatography of extracts, organic carbon and elemental analysis of coals and kerogens) gives further insights into the hydrocarbon potential of the basin. Although organic-rich rocks are relatively abundant, most source rocks that have achieved the levels of maturation necessary for hydrocarbon generation are gas-prone. The exinite-rich oil-prone Walloon Coal Measures are in most parts relatively immature. Some restraints on migration pathways are evident and igneous and tectonic events may have disturbed potentially well-sealed traps. Further exploration is warranted, even though the basin appears gasprone and the overall prospects for hydrocarbons are only fair. The most promising areas seem to be west of Toowoomba for oil and the Clarence Syncline for gas.

Martin, A.R.; Saxby, J.D.

1982-05-01

246

The Dnieper-Donets Paleorift, Ukraine: deep structures and hydrocarbon accumulations  

Energy Technology Data Exchange (ETDEWEB)

Numerous deep seismic and borehole studies have been made in the Dnieper-Donets Paleorift (Ukraine), and, when combined with studies of oil- and gasfield distribution, indicate that there exists an interesting relationship between deep lithospheric structure and evolution, and the hydrocarbon potential of the Paleorift. It has been found that hydrocarbon accumulations tend to be associated with slopes in the Moho dicontinuity, where most faults are located, and also where the basement and the lower layers of sedimentary cover have been fragmented by faults. These areas are the most promising for exploration. These facts could imply an abiogenic, mantle origin for oil and gas. Alternatively, the hot mantle ascending beneath the Dnieper-Donets Paleorift may have created thermodynamic or fluid-flow conditions within the sedimentary cover which were favourable for the transformation of biogenic material into oil and gas. In this case, mantle fluid-flow along faults assisted the migration of hydrocarbons and its accumulation in traps. (author)

Chekunov, A.V.; Kaluzhnaya, L.T. (AN Ukrainskoj SSR, Kiev (Ukraine). Inst. Geofiziki); Ryabchun, L.I. (AN Ukrainskoj SSR, Kiev (Ukraine). Inst. Geologicheskikh Nauk)

1993-04-01

247

IDChase: Mitigating Identifier Migration Trap in Biological Databases  

Science.gov (United States)

A convenient mechanism to refer to large biological objects such as sequences, structures and networks is the use of identifiers or handles, commonly called IDs. IDs function as a unique place holder in an application for objects too large to be of immediate use in a table which is retrieved from a secondary archive when needed. Usually, applications use IDs of objects managed by remote databases that the applications do not have any control over such as GenBank, EMBL and UCSC. Unfortunately, IDs are generally not unique and frequently change as the objects they refer to change. Consequently, applications built using such IDs need to adapt by monitoring possible ID migration occurring in databases they do not control, or risk producing inconsistent, or out of date results, or even face loss of functionality. In this paper, we develop a wrapper based approach to recognizing ID migration in secondary databases, mapping obsolete IDs to valid new IDs, and updating databases to restore their intended functionality. We present our technique in detail using an example involving NCBI RefSeq as primary, and OCPAT as secondary databases. Based on the proposed technique, we introduce a new wrapper like tool, called IDChase, to address the ID migration problem in biological databases and as a general platform.

Bhattacharjee, Anupam; Islam, Aminul; Jamil, Hasan; Wildman, Derek

248

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

249

Deep oxidation of chlorinated hydrocarbons  

Energy Technology Data Exchange (ETDEWEB)

Catalysts are described for the low temperature (<275{degrees}C), air oxidation of chlorinated hydrocarbons to CO{sub 2} and HCl. The catalysts are based on Ambersorb{reg_sign} adsorbents as carbonaceous supports. Nearly complete conversion results with the best of a series of catalyst to be discussed. When the hydrogen content of the chlorinated hydrocarbon is less than required for HCl formation, water can be added to satisfy this requirement. Experiments which suggest steps in a more complex total mechanism for deep oxidation are described.

Drago, R.S.; Petrosius, S.C.; Grunewald, G.C. [Univ. of Florida, Gainsville, FL (United States); Brendley, W.H. [Rohm & Haas Co., Spring House, PA (United States)

1993-12-31

250

Migration - utopia or myopia?  

Directory of Open Access Journals (Sweden)

Full Text Available Peter Osborne spent a sabbatical in northern America and was surprised that so many scientists and students stated that caribou migration was largely the result of mosquito pressure. He failed however to find any documented evidence of this claim although he was constantly confronted by the well known «facts» that mosquitoes had been observed to drive caribou crazy and even kill juveniles. The issue Osborne wishes to focus is that an experimentally unsubstantiated anthropomorphism appears to have become critical evidence in support of a theory. A recent article in Nature (393, 511-513, 1998 devoted to the uses of 'science in fiction' to stimulate thought and discussion about aspects of academia encouraged him to write the following comment in the form of a parody of ancient Greek dialogues.

Peter Osborne

1998-03-01

251

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

252

Endobronchial valve migration.  

Science.gov (United States)

Endobronchial valves are increasingly used as a treatment modality as a less invasive alternative to lung volume reduction surgery in patients with severe emphysema. Endobronchial valves have also been used to treat patients with persistent pulmonary air leaks and those with bronchopleural fistulae. We report a case of a 61-year-old male with severe bullous emphysema. Following video-assisted thoracoscopic surgery and giant bullectomy, he had a persistent air leak. We inserted two endobronchial valves (in the lingular lobe and the anterior segment of the upper lobe) and the air leak ceased immediately. However, over the subsequent 5 months following the insertion of the endobronchial valves, the patient suffered recurrent chest infections and the endobronchial valves were found to have migrated to the orifice of the basal segment of the left lower lobe and the orifice of the basal segments of the right lower lobe. PMID:21435897

Jenkins, Melanie; Vaughan, Paul; Place, David; Kornaszewska, Malgorzata

2011-11-01

253

Relationship between organic inclusions and hydrocarbon generation in Taibei depression in Donghai Basin  

Energy Technology Data Exchange (ETDEWEB)

Characteristics of organic inclusions and their homogenisation temperature were studied. The relationship between vitrinite reflectance (R{sub 0}) and the history of geological evolution was analysed. The result indicates that two times of oil and gas generation process has taken place in Taibei depression since Tertiary. The first time occurred in the end of E{sub 1} (end of Paleocene), in which the scale of hydrocarbon generation and migration was small because of the immaturity of organic matter, and only a few organic inclusions were formed in this time. The second time occurred in the end of E{sub 2} (end of Eocene), a period during which the main source rock generated hydrocarbon in its maximum amount. So, it was also the period of formation and migration of hydrocarbon, accompanied by the formation of a large number of organic inclusions. The sedimentary thickness of Neogene is similar to that of denudation at the end of E{sub 2}, which has only little influence on the formation and migration of oil and gas. 6 refs., 2 figs., 3 tabs.

Wang, Y.; Han, D.; Jiang, L.; Ge, H. [China University of Mining and Technology, Beijing (China). Dept of Resource Exploitation Engineering

2001-07-01

254

Mechanism of methanol conversion to hydrocarbons over HZSM-5  

International Nuclear Information System (INIS)

Studies of methanol conversion over HZSM-5 using _1_3C-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 C"1 coupling product, but rather a secondary product derived from methyl attack on C"3"+ 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

1982-01-01

255

Software Engineering Challenges of Migration Projects  

Directory of Open Access Journals (Sweden)

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

S.Geetha

2012-03-01

256

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

257

Contribution to Radiolysis Study of Liquid Hydrocarbons.  

Science.gov (United States)

This work deals with radiolysis of liquid hydrocarbons. First, the radiochemical yields of various products are correlated with the theoretical bond energies, for some hydrocarbons. Several values of scavenging parameter alpha sub(S) are calculated and th...

M. Rimbaud

1978-01-01

258

Water Solubility Behavior of Binary Hydrocarbon Mixtures.  

Science.gov (United States)

The aqueous solubility equilibrium behavior of seven medium molecular weight, liquid, binary hydrocarbon mixtures has been determined at 20 C. Binary hydrocarbon mixtures containing structurally similar compounds exhibited ideal solution behavior, but dev...

D. R. Burris W. G. MacIntyre

1985-01-01

259

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 ...

260

Cenozoic tectonic jumping and implications for hydrocarbon accumulation in basins in the East Asia Continental Margin  

Science.gov (United States)

Tectonic migration is a common geological process of basin formation and evolution. However, little is known about tectonic migration in the western Pacific margins. This paper focuses on the representative Cenozoic basins of East China and its surrounding seas in the western Pacific domain to discuss the phenomenon of tectonic jumping in Cenozoic basins, based on structural data from the Bohai Bay Basin, the South Yellow Sea Basin, the East China Sea Shelf Basin, and the South China Sea Continental Shelf Basin. The western Pacific active continental margin is the eastern margin of a global convergent system involving the Eurasian Plate, the Pacific Plate, and the Indian Plate. Under the combined effects of the India-Eurasia collision and retrogressive or roll-back subduction of the Pacific Plate, the western Pacific active continental margin had a wide basin-arc-trench system which migrated or ‘jumped’ eastward and further oceanward. This migration and jumping is characterized by progressive eastward younging of faulting, sedimentation, and subsidence within the basins. Owing to the tectonic migration, the geological conditions associated with hydrocarbon and gashydrate accumulation in the Cenozoic basins of East China and its adjacent seas also become progressively younger from west to east, showing eastward younging in the generation time of reservoirs, seals, traps, accumulations and preservation of hydrocarbon and gashydrate. Such a spatio-temporal distribution of Cenozoic hydrocarbon and gashydrate is significant for the oil, gas and gashydrate exploration in the East Asian Continental Margin. Finally, this study discusses the mechanism of Cenozoic intrabasinal and interbasinal tectonic migration in terms of interplate, intraplate and underplating processes. The migration or jumping regimes of three separate or interrelated events: (1) tectonism-magmatism, (2) basin formation, and (3) hydrocarbon-gashydrate accumulation are the combined effects of the Late Mesozoic extrusion tectonics, the Cenozoic NW-directed crustal extension, and the regional far-field eastward flow of the western asthenosphere due to the India-Eurasia plate collision, accompanied by eastward jumping and roll-back of subduction zones of the Pacific Plate.

Suo, Yanhui; Li, Sanzhong; Yu, Shan; Somerville, Ian D.; Liu, Xin; Zhao, Shujuan; Dai, Liming

2014-07-01

 
 
 
 
261

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

DEFF Research Database (Denmark)

The factors that drive partial migration in organisms are not fully understood. Roach (Rutilus rutilus), a freshwater fish, engage in partial migration where parts of populations switch between summer habitats in lakes and winter habitats in connected streams. To test if the partial migration trait is phenotypically plastic or has genetic components, we translocated roach from 2 populations with different opportunities for migration to a lake with migration opportunity, containing a local roach population. This enabled monitoring of partial migration of fish in 3 different situations: 1) previous opportunity for migration, migrating in a familiar environment (the local population); 2) previous opportunity for migration, migrating in an unfamiliar environment; and 3) no previous opportunity for seasonal migration, migrating in an unfamiliar environment. In addition, we evaluated the migration patterns of roach in the lake with migration opportunity where from group 2 fish were translocated. Directional migration in and out of the lakes was monitored using Passive Integrated Transponder technology. Translocated fish with previous migration opportunity showed migration patterns more similar to local fish than to their home lake population, and individuals translocated from the lake without migration opportunity migrated when given the opportunity, suggesting that partial migration is phenotypically plastic and triggered by lake-specific environmental cues. We found temperature to be a proximate cue for migration decisions. Individuals without previous migration opportunity migrated at a lower proportion and with different small-scale migration patterns, suggesting that also genetic components are involved in the expression of the partial migration trait.

Skov, Christian; Aarestrup, Kim

2010-01-01

262

Technique for separating hydrocarbon mixture containing aromatic and paraffin hydrocarbons  

Energy Technology Data Exchange (ETDEWEB)

Technique for separating mixture for hydrocarbons containing ArU and paraffin hydrocarbons with use of a liquid surfactant membrane, that contains Na. The membrane consists of a 0.5-2% aqueous solution of Na salts of fatty acids C/sub 10/-C/sub 20/. The mixture to be separated and aqueous solution are mixed; the emulsion is then carefully cleaned' with solvent, running it through the solvent for about 10-15 min. A selective penetration of components occurs (through the membrane) into the org. solvent. Thus three layers are formed. The lower layer is the aqueous surfactant solution, themiddle the solvent, containing the hydrocarbons that penetrated, and the upper is an emulsion of original hydrocarbons in a surfactant solution, enriched with the poorly penetrated component. From the middle and upper layers a binary mixture of hydrocarbons is removed and their composition is determined by refractometric means or with aid of ''GZhKh''. Example: Into 25 ml of hydrocarb. mixture, containing 50% benzole and 50% pure C/sub 6/H/sub 14/. The emulsion, enriched with more poorly penetrating component (pure C/sub 6/H/sub 14/), is destroyed; the derived product contains 39.5% benzole and 60.5% pure C/sub 6/H/sub 14/. This product is recirculated 1 time in same conditions. Enrichment with pure C/sub 6/H/sub 14/ product was increased: content of pure C/sub 6/H/sub 14/ 71.8%, benzole 28.2%.

Aliyeva, R.B.; Abdulayev, G.M.; Akhundova, T.Sh.; Alikishi-Zade, G.Yu.; Kuliyev, A.M.; Mekhtiyeva, Zh.M.

1979-09-18

263

Wages, Welfare Benefits and Migration.  

Science.gov (United States)

Differences in economic opportunities give rise to strong migration incentives, across regions within countries, and across countries. In this paper we focus on responses to differences in welfare benefits across States. We apply the model developed in Kennan and Walker (2008), which emphasizes that migration decisions are often reversed, and that many alternative locations must be considered. We model individual decisions to migrate as a job search problem. A worker starts the life-cycle in some home location and must determine the optimal sequence of moves before settling down. The model is sparsely parameterized. We estimate the model using data from the National Longitudinal Survey of Youth (1979). Our main finding is that income differences do help explain the migration decisions of young welfare-eligible women, but large differences in benefit levels provide surprisingly weak migration incentives. PMID:22844178

Kennan, John; Walker, James R

2010-05-01

264

[Health and migration. Psychosocial determinants].  

Science.gov (United States)

The article provides an overview of the contemporary literature on the social and psychological factors which are associated with migration. Derived from the operationalisation of "migration" and an examination of the methodological peculiarities of migration research, a (transactional) stress model of migration is proposed incorporating potentially stress-eliciting influences of migration including occupational pressures, social isolation and/or family-related problems and their impact on psychological and physical health. There are inconsistencies in the findings regarding psychological health, which can in part be explained through the phenomena of the "healthy migrant effect", duration of stay in the host culture or the culture-specificity. Moreover, a discussion is provided of the extent that disorders associated with differentially stressed migrants will be manifested in the health care system. Finally, concluding remarks are offered together with a short discussion of the implication of these findings for future research and social and health policy decision-making. PMID:16953359

Kirkcaldy, B; Wittig, U; Furnham, A; Merbach, M; Siefen, R G

2006-09-01

265

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.

2010-01-01

266

Migrating and herniating hydatid cysts  

International Nuclear Information System (INIS)

Objective: To present the prevalence and imaging findings of patients with hydatid disease (HD) showing features of migration or herniation of the hydatid cysts (HCs) and underline the clinical significance of this condition. Materials and methods: Between May 2003 and June 2006, 212 patients with HD were diagnosed by abdomen and/or thorax CT, searched for migrating or herniating HC. Imaging findings of 7 patients (5 women, 2 men with an age range of 19-63 years; mean ± S.D., 44 ± 19 years) with HD showing transdiaphragmatic migration (6 subjects) or femoral herniation (1 subject) were evaluated. Diagnosis of all the patients were established by pathologic examination and migration or herniation was confirmed by surgery in all patients. Results: Liver HD were identified in 169 (79.7%) of 212 patients with HD. Transdiaphragmatic migration of HCs were identified in 6 (3.5%) of the 169 patients with liver HD. In one patient, femoral herniation of the retroperitoneal HC into the proximal anterior thigh was identified. All of these seven patients exhibiting migration or herniation of HCs had active HCs including 'daughter cysts'. Two patients had previous surgery because of liver HD and any supradiaphragmatic lesion was not noted before operation. Findings of migration or herniation were confirmed by surgery. Conclusion: Active HCs may show migration or herniation due to pressure difference between the anatomic cavities, and in some of the patients, by contribution of gravity. Previous surgery may be a complementary factor for migration as seen in two of our patients. The possibility of migration or herniation in patients with HD should be considered before surgery

2008-01-01

267

Antarctica: geology and hydrocarbon potential  

Energy Technology Data Exchange (ETDEWEB)

The first impression of the hydrocarbon potential of Antarctica is generally negative. The environment is hostile and only 2% of the continent is seen through the ice. Careful study of the surprisingly ample volume of published data available on the geology and geophysics and Antarctica, coupled with the application of the principles and mechanics of plate tectonics relative to the oceans and adjacent land masses, gives a different and very positive attitude toward the hydrocarbon potential of this vast unexplored frontier area. On the basis of limited data, 21 sedimentary basins are identified for Antarctica and immediately adjacent areas. These include six onshore subglacial basins and 15 offshore basins. Excluding 11 basins considered to have little or no potential, the other 10 basins contain an estimated 16.9 million km/sup 3/ (4.05 million mi/sup 3/) of sediment having a potential hydrocarbon yield of 203 billion bbl oil equivalent. The problems associated with hydrocarbon exploration in Antarctica are formidable. Technology is adequate for seismic surveys and exploratory drilling of the Antarctic continental shelf, as concluded from current operations in the Arctic and from operating requirements of drilling rigs under construction. However, a working relationship among involved nations must first be evolved and production, storage, and transportation problems solved.

St. John, B.

1984-09-01

268

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

269

Rock physics for hydrocarbon recovery monitoring  

Science.gov (United States)

Monitoring hydrocarbon resources through repeated seismic surveys (4D seismic) is a potentially powerful technique. It often works because variations in fluid saturation, pore pressure, and temperature during oil/gas recovery change the stiffness of the reservoir rock and, in turn, the compressional and shear-wave velocities. These temporal changes can be observed through periodic seismic surveys. In principle, they allow one to detect fluid migration, permeability barriers, and bypassed hydrocarbons, thus leading to improved recovery. Rock physics quantitatively links changes in saturation, temperature, and pressure to velocity changes. In this thesis, I provide a rock physics methodology for interpreting 4D seismic for fluid location and pressure changes. First, I develop two models for possible fluid distribution in rock, uniform and patchy. By applying these models to reservoir simulation data, I show that fluid distribution can significantly affect the velocity and thus seismic reservoir signatures. Specifically, I find that changes in the seismic signature that accompany small changes in gas saturation in a developing gas cone can often be masked by noise if saturation is patchy. On the other hand, these changes are readily observable if saturation is uniform. Using well log data, I show that patchy saturation exists at the logging frequency scale, and, therefore, is likely at the seismic scale. Thus it is important to consider the distinct saturation patterns introduced here. Other parameters that can affect the detectability of recovery-associated changes in a reservoir are rock frame stiffness and pore pressure. To explore the effect of frame stiffness, I use reservoir simulation data together with three different realistic models that link rock stiffness to porosity. I find that increasing rock frame stiffness reduces the seismic visibility of a developing gas cone. To illustrate the effect of pore pressure, I model the velocity and reflectivity at the top of an uncemented gas sand at two pore pressure values. Synthetic CDP gathers show that an increase in the velocity associated with pore pressure reduction results in reduced reflectivity at the top and base and velocity pull-up at the base of the sand.

Packwood, James Lee

1998-11-01

270

DNAPL migration in a coastal plain aquifer  

Energy Technology Data Exchange (ETDEWEB)

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.

DiGuiseppi, W.H.; Jung, A.D. [Consoer Townsend Envirodyne Engineers, Inc., Fairfax, VA (United States)

1995-12-31

271

Labour Migration and Network Effects in Moldova  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This study investigates the impact of migration networks on the decision to migrate in Moldova. Using a recent cross-sectional household survey with extensive migration information I am able to disaggregate the migration networks according to kinship and further investigate the impact of different kinds of networks. The results show that migration networks have a significant positive impact on the decision to migrate, whereas the results do not reveal any conclusive evidence that certain kins...

Andersson, Lisa

2008-01-01

272

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

273

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

274

Secondary Controlled Swing Drive  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Pettersson, Karl

2008-01-01

275

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.

276

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

277

Collaborative Surface Migration Behavior of Proteus mirabilis  

Science.gov (United States)

Collaborative migration behavior exerted by Proteus mirabilis cells on the surface of a low-agar medium. The organisms were differentiating into elongated hyperflagellates and gathering for migration.

American Society For Microbiology;

2008-11-07

278

The change in the chemical and isotopic composition of hydrocarbons by the maturation of petroleum  

International Nuclear Information System (INIS)

Pyrolysis experiments were carried out with crude oil (fraction above 300 0C) with different reaction times and temperatures in ampullas as well as in a pressure vessel. The hydrocarbons formed and initial and residual oil were analyzed chemically and isotopically to find possible differences in the criteria of genesis. Because the organic substance is often bound to clay rocks, further investigations are described on the influence of natural catalysts such as montmorillonite and kaolonite on the formation of gas from crude oil. Because during the thermal treatment of crude oil there are formed not only methane but also liquid hydrocarbons, further investigations are necessary on primary and secondary formation of condensate. (author)

1986-09-22

279

Radial Migration in Spiral Galaxies  

CERN Document Server

The redistribution of stars in galactic disks is an important aspect of disk galaxy evolution. Stars that efficiently migrate in such a way that does not also appreciably heat their orbits can drastically affect the stellar populations observed today and therefore influence constraints derived from such observations. Unfortunately, while the theoretical understanding of the migration process is becoming increasingly robust, there are currently few specific observable predictions. As a result, we do not yet have a clear handle on whether the process has been important for the Milky Way in the past or how to constrain it. I discuss some of the expected qualitative outcomes of migration as well as some current controversies.

Roškar, R

2014-01-01

280

UK Migration Policy and Migration from Eastern Partnership Countries  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper examines UK migration policy and recent migration flows from Eastern Partnership (EaP) countries to the UK. Although inflows of migrant workers were relatively large in the mid-2000s, especially amongst Ukrainians, these have fallen following changes to UK immigration policy, especially the Seasonal Agricultural Workers Scheme and the introduction of the Points Based System. As a result, the stock of migrants from EaP countries resident in the UK is small, especially in comparison ...

Clark, Ken; Drinkwater, Stephen

2013-01-01

 
 
 
 
281

Hydrocarbon generation from deltaic and intermontane fluviodeltaic coal and coaly shale from the Tertiary of Texas and Carboniferous of Nova Scotia  

Energy Technology Data Exchange (ETDEWEB)

Selected samples of coal and coaly shale from southeastern Texas (depositional environment: deltaic; Age: Paleocene-Eocene; R{sub o}: 0-25-0.75%) and Nova Scotia (depositional environment: intermontane swamp, delta and lacustrine; Age: Carboniferous-Westphalian A-D; R{sub o}: 0.67-0.70%) were analyzed by fluorescence microscopy, Rock-Eval pyrolysis, NMR, anhydrous pyrolysis (temperature programmed and flash) and hydrous pyrolysis to evaluate the hydrocarbon potential and hydrocarbon types. Based on maceral assemblages, palynofacies and hydrocarbon potential, these coals and coaly shale samples are classified as humic, mixinitic (mixed) and sapropelic. Mixinitic (or mixed) coal and coaly shale containing mainly humodetrinite and lipodetrinite generated more than 10% pyrolysate (expelled oil + oil in wash fraction + remaining coal extract) and show bimodal n-alkane distribution (derived from cutinite, suberinite and alginite). Pyrolysis of humotelinite/humocollinite-rich and liptinite-poor humic coals generated low amounts ({lt}10%) of pyrolysates, mainly consisting of low molecular weight hydrocarbons. A modified model of oil-prone and non-oil-prone coal types, related to depositional environments, is proposed. A new concept of primary migration is proposed: the humodetrinite-liptodetrinite network of mixinitic (or mixed) and sapropelic coal (excluding exsudatinite) acts as a migration pathway for liquid hydrocarbons which migrate as a hydrocarbon phase. According to pyrolysis, NMR, organic petrography and the primary migration concept, mixinitic (or mixed) coal or coaly shale are considered as likely source rocks for liquid hydrocarbons within deltaic and intermontane basins. 46 refs., 10 figs., 4 tabs.

Mukhopadhyay, P.K.; Hatcher, P.G.; Calder, J.H. (Global Geoenergy Research Ltd., Halifax, NS (Canada))

1991-01-01

282

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. PMID:22115086

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

2011-11-01

283

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

284

Solid Propellant Ingredient Migration Studies.  

Science.gov (United States)

Reported herein is the development of a unique solid propellant ingredient separation device. Use of this separation device was applied to the determination of labile solid propellant ingredient migration rates, propellant/liner plasticizer distribution r...

L. A. Dee L. J. Emmanuel M. E. Fiske L. Ninomiya

1982-01-01

285

MRI of neuronal migration disorders  

International Nuclear Information System (INIS)

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

1996-07-01

286

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

Energy Technology Data Exchange (ETDEWEB)

The theory of the abyssal abiotic petroleum origin considers oil and natural gas to be generated 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 data, presented in this thesis, confirms the possibility of hydrocarbons formation from mantle inorganic compounds (water, Fe, CaCO{sub 3} or graphite) at temperature and pressure of the upper mantle (1500 K and 5 GPa). Experiments were carried out in CONAC high pressure device and multianvil apparatus BARS. Compositions of received gas mixtures were similar to natural gas. Quantity of hydrocarbons depended on the cooling regime of reaction mixture under pressure. Slow cooling favored higher quantity. We found that donor of carbon (CaCO{sub 3} or graphite) determines formation of 'dry' (methane-rich) gas or 'wet' (light hydrocarbons-rich) gas. Experiments in laser-heated diamond anvil cells showed that methane and ethane partially react under upper mantle thermobaric conditions (2-5 GPa, 1000-1500 K) to form mixture of hydrocarbons: methane, ethane, propane and n-butane - main compounds of natural gas. Similarity of final product mixture obtained from methane and ethane means thermodynamic stability of hydrocarbons in the thermobaric conditions of the upper mantle and equilibrium character of the observed processes

Kolesnikov, Anton

2010-12-15

287

Melting secondary aluminium  

Energy Technology Data Exchange (ETDEWEB)

After a short introduction, this Guide examines the secondary aluminium industry, and describes the postal questionnaire survey of secondary aluminium melting facilities. Opportunities for energy saving are identified, and the aims of the Energy Efficiency Office's Best Practice Programme are outlined. (author)

1994-06-01

288

An aqueous hydrocarbon oil emulsion  

Energy Technology Data Exchange (ETDEWEB)

The aqueous emulsion of hydrocarbon oil, which includes black oil, potassium or sodium xanthate and water, is distinguished by the fact that in order to form a stable, finely dispersed emulsion of black oil in water, it additionally contains one and two atomic alcohols of the dioxane and pyrane series with the following component ratio in percent by weight: black oil, 2.0-4.2; potassium or sodium xanthate, 0.95-1.7; one and two atomic alcohols of the dioxane and pyrane series, 4-8.6 and water, the remainder. The aqueous black oil emulsion is not bound with the use of highly aggressive solutions, but the proposed stabilizers are used in the technological process as the basic reagents for a collector and a foamer. The use of the aqueous hydrocarbon oil emulsion will provide a savings of 70,000 rubles in a single f-k.

Kogan, D.I.; Beskrovnaya, V.P.

1980-02-18

289

Hydrocarbon Rocket Technology Impact Forecasting  

Science.gov (United States)

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

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

2012-01-01

290

Scottish hydrocarbons: Borders and bounty  

International Nuclear Information System (INIS)

On 6 May, the people of Scotland will vote for the country's first parliament in almost three centuries. One issue is expected to arouse particularly strong views: the question of North Sea oil and gas, and who benefits from its production and taxation. Most of these hydrocarbons lie in the northern half of the British Isles, but drawing boundaries to settle contentious issues such as oil and gas fields is not an easy task. And, if boundaries were to be drawn, then a scarcely less contentious subject arises: just how much cash might an independent Scotland expect to receive? Reading between the lines it's clear that in hard cash terms, were Scotland to be independent whilst still retaining the vast bulk of North Sea oilfields, depressed prices would ensure that hydrocarbon tax revenues would be unlikely to constitute a particularly impressive addition to the Scottish Treasury. (UK)

1999-01-01

291

Tomographic imaging of residual hydrocarbon in water saturated unconsolidated sediments  

Science.gov (United States)

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 and hydrocarbon distribution be understood. The objectives of this thesis work is to determine if acoustic methods can (1) delineate sediment structure caused by variation in grain size and (2) delineate the amount and spatial distribution of residual hydrocarbon. Naturally occurring sediments are often complicated in composition and structure that results in a range of seismic attenuation mechanisms. For this study, synthetic sediments with idealized 3-D sediment structures were created from glass beads (with known composition and geometry) saturated with two fluid phase: water and paraffin wax. A series of control experiments were performed using different saturation techniques to (1) explore the immiscible fluid displacement processes and (2) to study the effect of amount and the spatial distribution of the immiscible fluid residue on the acoustic response. An acoustic tomographic approach was used to delineate the 3-D sediment structure and to study the effect of sediment structure on the amount and the spatial distribution of the immiscible fluid. From the control experiments, it was determined that the saturation method affected the residual wax distribution in the pores. The residual wax distribution can be categorized into four types, i.e. bridging, thin fingering, cements at grain contacts, and patchy saturation. The tomographic experiments determined that sediment structure caused by a variation in grain size could barely be determined seismically. However, the 3-D sediment structure was clearly determined when residual paraffin resided in the sediment. Even residual saturation of less than 1% altered the seismic signal of the sediments. Seismic-wave attenuation and velocity is sensitive to alteration of the grain contact stiffness even for only a few percent residual hydrocarbon saturation and to spatial features that are ˜1/100 of a wavelength. Thus the affect of micro-scale phenomena on macro-scale measurements of seismic wave attenuation and velocity cannot be ignored.

Li, Xun

2002-08-01

292

Return Migration and Working Choices  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Tani, Massimiliano; Mahuteau, Ste?phane

2008-01-01

293

Zero Overhead Java Thread Migration  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Bouchenak, Sara; Hagimont, Daniel

2002-01-01

294

Migrations, public goods and taxes  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper examines how and why people migrate between two regions with asymmetric size. The agglomeration force comes from the scale economies in the provision of local public goods, whereas the dispersion force comes from congestion in consumption of public goods. Public goods considered resemble club goods (or public goods with congestion) and people are heterogeneous in their migration costs. We find that the large countries can be destination of migrants for sufficiently high provision o...

Gabszewicz, Jean; Gvetadze, Salome; Zanaj, Skerdilajda

2011-01-01

295

SSI, labor supply, and migration  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Neumark, David; Powers, Elizabeth T.

2005-01-01

296

Essays on Growth and Migration  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Essays on Growth and Migration is a collection of papers that analyze how two particular factors, the brain drain and the intellectual property rights (IPR), affect the economic performance of a given country. The theoretical models are constructed and illustrative empirical examples are provided in order to understand better the role of these factors in the process of economic development. Brain drain refers to migration of high-skilled, trained and talented individuals. Even though it was c...

Stryszowski, P. K.

2009-01-01

297

The aryl hydrocarbon receptor repressor  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The aryl hydrocarbon receptor repressor (AHRR) is a bHLH/Per-ARNT-Sim transcription factor located in a region of chromosome 5 (5p15.3) that has been proposed to contain one or more tumor suppressor genes. We report here consistent downregulation of AHRR mRNA in human malignant tissue from different anatomical origins, including colon, breast, lung, stomach, cervix, and ovary, and demonstrate DNA hypermethylation as the regulatory mechanism of AHRR gene silencing. Knockdown of AHR...

Zudaire, Enrique; Cuesta, Natalia; Murty, Vundavalli; Woodson, Karen; Adams, Lisa; Gonzalez, Nieves; Marti?nez, Alfredo; Narayan, Gopeshwar; Kirsch, Ilan; Franklin, Wilbur; Hirsch, Fred; Birrer, Michael; Cuttitta, Frank

2008-01-01

298

Catalytic method for synthesizing hydrocarbons  

Energy Technology Data Exchange (ETDEWEB)

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

299

Catalytic method for synthesizing hydrocarbons  

Energy Technology Data Exchange (ETDEWEB)

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 cobalta carbonyl or precursors thereof. The catalyst exhibits excellent activity, stability in air, and produces highly desirable products fractions even with dilute gaseous reactants.

Sapienza, R.S.; Sansone, M.J.; Slegeir, W.A.R.

1984-07-17

300

Hydrocarbons hydrogenation; Hydrogenation des hydrocarbures  

Energy Technology Data Exchange (ETDEWEB)

The partial or total hydrogenations (selective or not) of unsaturated hydrocarbons are the main chemical reactions of petroleum refining processes and of production of chemical compounds for petrochemistry. After having recalled some generalities about hydrogenations (thermodynamics, kinetics, chemical processes, possible used catalysts), the authors describe into details the different processes used for the selective, partial and total hydrogenations of alkenes, alkadienes, alkynes, dienes (cyclopentadiene) and aromatics (particularly benzene and naphthalene). (O.M.) 37 refs.

Cosyns, J. [Louvain Univ. (Belgium)]|[Institut Francais du Petrole (IFP), 92 - Rueil-Malmaison (France); Martino, G. [Ecole Nationale Superieure du Petrole et des Moteurs (ENSPM), 92 - Rueil-Malmaison (France)]|[Louvain Univ. (Belgium)]|[Institut Francais du Petrole (IFP), 92 - Rueil-Malmaison (France)

1997-03-01

 
 
 
 
301

Deep desulfurization of hydrocarbon fuels  

Energy Technology Data Exchange (ETDEWEB)

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

302

Identification of polycyclic aromatic hydrocarbons  

International Nuclear Information System (INIS)

The nature of the Very Small Grains evidenced by K. Sellgren (1985) is discussed. Their stability suggests that they are graphitic material and specifically polycyclic aromatic hydrocarbons (PAHs). The expected infrared emission of a typical PAH, coronene, gives an impressive spectroscopic agreement with the five observed Unidentified IR Emission Features, leading to an unambiguous identification. Those PAHs are the most abundant organic molecules detected to date (f is approximately 00001)

1986-10-01

303

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

2012-01-01

304

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

305

$100 million for hydrocarbon exploration  

Energy Technology Data Exchange (ETDEWEB)

The hydrocarbon and base metal potential of the onshore and offshore segments of the Hudson Platform will be the focus of a $100 million, 5 year study undertaken by the Geological Survey of Canada (GSC) together with the Nunavut, Ontario, Quebec and Manitoba provincial surveys. This geological region encompasses 25 per cent of Canada's landmass. Seventy-five per cent of the budget will be spent in the Canadian Arctic, with the remainder committed to studying the Hudson Platform in Ontario, Quebec and Manitoba. The GSC has stated that although the geoscience information is limited, there are indications that world-class hydrocarbon source rocks are present. Very porous potential reservoir units have been identified. The project will define the basic elements of the hydrocarbon systems in the Hudson and Foxe Basins. According to the thermal conditions in the Hudson Platform, it is probably an oil domain. However, gas may exist in the thicker successions in the northern part of Hudson Bay. The young Devonian rock units in northern Ontario have the potential to eventually generate shallow natural gas called shale gas, a new target that is currently being developed in northern British Columbia. GSC researchers will also study gas escape structures known as pockmarks, discovered during a seafloor mapping program in the northern part of Hudson Bay. The geoscience data will also contribute to land use planning and provide a better understanding on the potential for gas hydrates. 2 refs., 1 fig.

Tollinsky, N.

2009-12-01

306

Aromatization catalysts for light hydrocarbons  

Energy Technology Data Exchange (ETDEWEB)

The aromatization catalysts for effective utilization of light hydrocarbons which are forecasted to be excess in recent years were introduced. ZSM-5 zeolite catalysts have zigzag structure with a pore diameter of 6 A. The catalysts produce BTX from feed hydrocarbons with carbon numbers of more than one, and have a long catalyst life. By Cyclar process with improved ZSM-5, the products with benzene 18-19 %, toluene 27-29 % and xylene 11-13 % were produced from the feed of propane and/or butane. However, the deactivation rate of the catalyst was faster in case of the feed of C5, C6 hydrocarbons. A L-type zeolite catalyst with platinum converts the C5, C6 feed into benzene, toluene with high selectivity, it is suited to the situations of the feeds in Japan. The pore diameter is 7.1-7.8 A, and it is considered that the activities are raised by platinum with excessive electrons in the pore. However, the deactivations due to the carbon deposit and the sintering of platinum particles are problems, and there are some restrictions in the regeneration of the catalyst and the operating conditions of the process. (5 figs, 3 tabs, 21 refs)

Katsuno, Hisashi

1988-03-01

307

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

308

A study of hydrocarbon contamination in glacial till  

International Nuclear Information System (INIS)

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

1991-05-14

309

Pressure sealing: An important agent for hydrocarbon entrapment  

Energy Technology Data Exchange (ETDEWEB)

Undercompacting shales, overlying a hydrocarbon reservoir act as an effective pressure seal, primarily because of their excess fluid pressure, high ductility and high capillary pressure. These characteristics restrict vertical flow of the reservoir fluids. Although it can be helpful in any trapping situation, pressure seal is particularly effective for deep and tight gas reservoirs in areas near a tectonic belt. In such areas, accumulated gas could have been lost to the surface through fractures and faults as a result of tectonism, unless the reservoir was properly sealed by pressure seal. The ductile nature of the seal would close the fracture openings almost instantly (geologically speaking). Such a self-sealing mechanism would have limited the upward loss of natural gas. A pressure seal can also prevent the downward movement of near-surface fresh water, after a tectonic event, which could deteriorate the quality of the accumulated hydrocarbons by water-washing and biodegradation. A pressure seal is formed at an intermediate stage of compaction when the permeability of the shale was reduced to the level beyond which normal compaction and normal fluid expulsion can no longer take place. Geologic time and burial depth of the pressure-seal formation may be interpreted in conjunction with the period of hydrocarbon generation, maturation and migration as well as of trap formation for a better assessment of petroleum prospect. Pressure seals are known to be important in many regions, such as Louisiana-Texas Gulf Coast, US Rocky Mountains, California Coast Ranges, various Canadian basins, North Sea, Niger Delta, Venezuela and Argentina. 15 figs., 17 refs.

Magara, K. (United Arab Emirates Univ., Al Ain (United Arab Emirates))

1993-02-01

310

Teaching secondary mathematics  

CERN Document Server

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

Rock, David

2013-01-01

311

Individual Decisions to Migrate During Civil Conflict  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The existing literature on forced migration limits our understanding of how violence affects migration to competing destinations. This article adds to the literature on forced migration by studying how armed violence during a period of civil conflict in south-central Nepal influenced the likelihood of local, internal, and international migration. We find that violence has a nonlinear effect on migration, such that low to moderate levels of violence reduce the odds of movement, but when violen...

2011-01-01

312

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

313

Four empirical essays on international migration  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This thesis investigates four different economic issues related to international migration from a new perspective. The first novelty consists in looking at migration as a “gendered process”. Little research has indeed addressed the issue of female migration until the last decades. Women were largely invisible in migration studies. Statistics on female migration were absent and females were mostly viewed as dependents, moving as wives, mothers or daughters of male migrants. Using the newly...

Salomone, Sara

2011-01-01

314

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

Science.gov (United States)

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

315

Before the Bonanza: Hydrocarbons in Greenland  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

2010-01-01

316

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

317

Controlled-aperture wave-equation migration  

Energy Technology Data Exchange (ETDEWEB)

We present a controlled-aperture wave-equation migration method that no1 only can reduce migration artiracts due to limited recording aperlurcs and determine image weights to balance the efl'ects of limited-aperture illumination, but also can improve thc migration accuracy by reducing the slowness perturbations within thc controlled migration regions. The method consists of two steps: migration aperture scan and controlled-aperture migration. Migration apertures for a sparse distribution of shots arc determined using wave-equation migration, and those for the other shots are obtained by interpolation. During the final controlled-aperture niigration step, we can select a reference slowness in c;ontrollecl regions of the slowness model to reduce slowncss perturbations, and consequently increase the accuracy of wave-equation migration inel hods that makc use of reference slownesses. In addition, the computation in the space domain during wavefield downward continuation is needed to be conducted only within the controlled apertures and therefore, the computational cost of controlled-aperture migration step (without including migration aperture scan) is less than the corresponding uncontrolled-aperture migration. Finally, we can use the efficient split-step Fourier approach for migration-aperture scan, then use other, more accurate though more expensive, wave-equation migration methods to perform thc final controlled-apertio.ee migration to produce the most accurate image.

Huang, L. (Lian-Jie); Fehler, Michael C.; Sun, H. (Hongchuan); Li, Z. (Zhiming)

2003-01-01

318

Neuropathy secondary to drugs  

Science.gov (United States)

Neuropathy secondary to drugs is a loss of sensation or movement in a part of the body ... weakness. Many medications may affect the development of neuropathy, including: Heart or blood pressure medications Amiodarone Hydralazine ...

319

Secondary Alkaline Batteries.  

Science.gov (United States)

This report on secondary alkaline batteries covers the overall reactions (charge/discharge characteristics), electrode structures and materials, and cell construction. The following batteries are studied, nickel oxide-cadmium, nickel oxide-iron, nickel ox...

J. McBreen

1984-01-01

320

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

 
 
 
 
321

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

322

The hydrocarbon habitat of northern South America: Colombia-Venezuela-Trinidad  

Energy Technology Data Exchange (ETDEWEB)

A prolific hydrocarbon province extends across the northern margin of South America from Colombia to east of Trinidad. Two key components are a world-class source rock, formed on a regional Late Cretaceous passive margin, and a complex tectonic setting in which a variety of structural and stratigraphic traps, reservoirs, seals and hydrocarbon kitchens have evolved through time. Convergence between the Farallon and Caribbean plates with South America culminated in the late Cretaceous-early Palaeogene with emplacement of Colombia`s Central Cordillera in the west and a nappe-foreland basin system in the north. Regional hydrocarbon generation probably occurred below associated basins. Subsequent oblique convergence between the Caribbean and South America, partitioned into strike-slip and compressional strain, generated an eastward migrating and ongoing uplift-foredeep (kitchen) system from central Venezuela to Trinidad. Similarly, oblique interaction of western Colombia with the Nazca Plate caused segmentation of the earlier orogen, northward extrusion of elements such as the Maracaibo Block, and eastward migration of uplift progressively dividing earlier kitchens into localized foredeeps.

James, K.H. [Conoco, Inc., Houston, TX (United States)

1996-08-01

323

Selective Transport of Hydrocarbons in the Unsaturated Zone Due to Aqueous and Vapor Phase Partitioning  

Science.gov (United States)

Long-term groundwater contamination can result from vapors and solutes emanating from organic liquids spilled in the unsaturated zone. The mathematical modeling analysis presented in this paper demonstrates for gasoline-range hydrocarbons, and other volatile organics commonly spilled, that diffusive transport in the unsaturated zone is a significant transport mechanism which can cause aqueous and vapor plumes to spread away from the immiscible liquid source, resulting in increasing groundwater contaminating potential. An analytical solution to a one-dimensional version of the transport model allows for the definition of a retardation coefficient which is dependent on phase-partitioning coefficients and moisture content. Significant differences in migration rates should be anticipated between hydrocarbons. A numerical solution was developed for a radially symmetric version of the model defining transport for a multiconstituent contaminant like gasoline. Differences in anticipated migration rates between aromatic and nonaromatic hydrocarbons was clearly demonstrated. A simulation based on the composition of an actual gasoline revealed that aromatic constituents, although constituting a fraction of the initial gasoline composition, completely defined the groundwater contaminating potential. This potential changes in time as constituents are selectively removed from the unsaturated zone. Further, the groundwater contaminating potential is quite sensitive to the ground surface boundary characterization.

Baehr, Arthur L.

1987-10-01

324

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

2012-01-01

325

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 m"2/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.)

1978-01-01

326

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

327

The brown dwarf desert as a consequence of orbital migration  

CERN Document Server

We show that the dearth of brown dwarfs in short-period orbits around Solar-mass stars - the brown dwarf desert - can be understood as a consequence of inward migration within an evolving protoplanetary disc. Brown dwarf secondaries forming at the same time as the primary star have masses which are comparable to the initial mass of the protoplanetary disc. Subsequent disc evolution leads to inward migration, and destruction of the brown dwarf, via merger with the star. This is in contrast with massive planets, which avoid this fate by forming at a later epoch when the disc is close to being dispersed. Within this model, a brown dwarf desert arises because the mass at the hydrogen burning limit is coincidentally comparable to the initial disc mass for a Solar mass star. Brown dwarfs should be found in close binaries around very low mass stars, around other brown dwarfs, and around Solar-type stars during the earliest phases of star formation.

Armitage, P J; Armitage, Philip J.; Bonnell, Ian A.

2002-01-01

328

SECONDARY AORTODUODENAL FISTULA  

Digital Repository Infrastructure Vision for European Research (DRIVER)

"nSecondary aortoenteric fistula (SAF) is an uncommon but very important complication of abdominal aortic reconstruction. The complication often occurs months to years after aortic surgery. The clinical manifestation of the aortoenteric fistula is always upper gastrointestinal bleeding. Treatment of the disease is early surgical intervention. If operative treatment is not performed promptly, the mortality is high. We present a case of secondary aortoduodenal fistula found 6 years after a...

Mohammadzade, M. A.; Mohammadzade, M. H. Akbar A.

2007-01-01

329

Coals as source rocks for hydrocarbon generation in the Taranaki Basin, New Zealand: a geochemical biomarker study  

Science.gov (United States)

The Taranaki Basin area provides the only source of commercial hydrocarbons in New Zealand. These are contained in the offshore Maui (gas-condensate) and onshore Kapuni (gas-condensate), Kaimiro (gas-condensate), and McKee (oil) fields. In addition a number of other smaller onshore fields have been discovered recently. The terrestrial coal measures of the Kapuni Group (Eocene) are now considered to be the source rocks for the onshore fields. The generated hydrocarbons are generally reservoired in the upper Kapuni Group sands. A summary of the results of the biomarker study of the triterpane hopanes and steranes extracted from coals in the deeper region of a selection of wells from the onshore Stratford, Kaimiro, Mangahewa and McKee fields and also from the produced condensates and oils, are presentedhere. These results show that the produced hydrocarbons have thermal maturities comparable to or approaching those of the deepest coals encountered on drilling within the Kapuni Group. Thus although the hydrocarbons may be generated within the Kapuni Group coals they are expelled only from the deepest coals within this Group or possibly the older (Paleocene-Upper Cretaceous) coals of the underlying Pakawau Formation, thereby exhibiting higher maturity levels. The presence of specific biomarkers in the produced hydrocarbons suggests the possibility of multiple source rocks and that the hydrocarbons have migrated to their present shallower reservoirs.

Johnston, J. H.; Collier, R. J.; Maidment, A. I.

330

Hydrothermal dolomitization in the Lower Silurian La Vieille Formation in northeastern New Brunswick : field evidence and implication for hydrocarbon exploration  

Energy Technology Data Exchange (ETDEWEB)

Hydrothermal dolomites are known to host hydrocarbon reservoirs. As such, they are a significant play for exploration companies seeking large hydrocarbon reservoirs in North America. The process has recently been documented in the Gaspe Peninsula and also in northern New Brunswick. The Gaspe Belt extends from the eastern Gaspe Peninsula in Quebec southwest through New Brunswick to northeastern Maine. 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. During the summer of 2004, six stratigraphic sections of the Lower Silurian La Vieille Formation were examined for facies architecture. Field observations that corroborate hydrothermal alteration of the La Vieille Formation in northern New Brunswick 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. Evidence shows that the formation has undergone early hydrothermal alternation that resulted in dolomitization, brecciation, 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 segments of northern New Brunswick is favourable for preservation of hydrocarbons and that Upper Ordovician hydrocarbon source rocks may be present. 27 refs., 5 figs.

Lavoie, D. [Natural Resources Canada, Quebec, PQ (Canada). Geological Survey of Canada, Quebec Division

2005-07-01

331

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

332

Hydrocarbon Formation in Immature Sediments  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 ...

Antia, D. D. J.

2011-01-01

333

Commercial valuation of hydrocarbon resources  

Energy Technology Data Exchange (ETDEWEB)

A practical business process is described which enables all categories of hydrocarbon resources to be valued in a commercially consistent manner. The benefits of the process are increased if there is a transparent corporate strategic plan which can be used to test the value of a resource against a desired portfolio, described quantitatively in terms of value and risk. Individual opportunities for both acquisition and disposal can then be measured against an assessed ``Corporate preference profile`` and pursued with increased confidence in the overall fit.

Boardman, J.S.

1995-10-01

334

Commercial valuation of hydrocarbon resources  

International Nuclear Information System (INIS)

A practical business process is described which enables all categories of hydrocarbon resources to be valued in a commercially consistent manner. The benefits of the process are increased if there is a transparent corporate strategic plan which can be used to test the value of a resource against a desired portfolio, described quantitatively in terms of value and risk. Individual opportunities for both acquisition and disposal can then be measured against an assessed ''Corporate preference profile'' and pursued with increased confidence in the overall fit

1995-03-20

335

Brownian Motion in Planetary Migration  

CERN Multimedia

A residual planetesimal disk of mass 10-100 Earth masses remained in the outer solar system following the birth of the giant planets, as implied by the existence of the Oort cloud, coagulation requirements for Pluto, and inefficiencies in planet formation. Upon gravitationally scattering planetesimal debris, planets migrate. Orbital migration can lead to resonance capture, as evidenced here in the Kuiper and asteroid belts, and abroad in extra-solar systems. Finite sizes of planetesimals render migration stochastic ("noisy"). At fixed disk mass, larger (fewer) planetesimals generate more noise. Extreme noise defeats resonance capture. We employ order-of-magnitude physics to construct an analytic theory for how a planet's orbital semi-major axis fluctuates in response to random planetesimal scatterings. To retain a body in resonance, the planet's semi-major axis must not random walk a distance greater than the resonant libration width. We translate this criterion into an analytic formula for the retention effi...

Murray-Clay, R A; Murray-Clay, Ruth A.; Chiang, Eugene I.

2006-01-01

336

The International-Migration Network  

CERN Document Server

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

Fagiolo, Giorgio

2012-01-01

337

Families, children, migration and AIDS.  

Science.gov (United States)

Migration is very often a family affair, and often involves children, directly or indirectly. It may give rise to better quality of life for an entire family, or to bitter disappointment, and may also increase vulnerability to HIV and AIDS. This review, carried out for the Joint Learning Initiative on Children and AIDS, links the literature on "migration", on "HIV and AIDS" and on "families". Three themes are sketched: (1) As both HIV prevalence and circular migration increase, former migrant workers affected by AIDS may return to their families for care and support, especially at the end of life, often under crisis conditions. Families thus lose promising members, as well as sources of support. However, very little is known about the children of such migrants. (2) Following patterns of migration established for far different reasons, children may have to relocate to different places, sometimes over long distances, if their AIDS-affected parents can no longer care for them. They face the same adaptation challenges as other children who move, but complicated by loss of parent(s), AIDS stigma, and often poverty. (3) The issue of migrant families living with HIV has been studied to some extent, but mainly in developed countries with a long history of migration, and with little attention paid to the children in such families. Difficulties include involuntary separation from family members, isolation and lack of support, disclosure and planning for children's care should the parent(s) die and differences in treatment access within the same family. Numerous research and policy gaps are defined regarding the three themes, and a call is made for thinking about migration, families and AIDS to go beyond description to include resilience theory, and to go beyond prevention to include care. PMID:22380978

Haour-Knipe, Mary

2009-01-01

338

Scattering and; Delay, Scale, and Sum Migration  

Energy Technology Data Exchange (ETDEWEB)

How do we see? What is the mechanism? Consider standing in an open field on a clear sunny day. In the field are a yellow dog and a blue ball. From a wave-based remote sensing point of view the sun is a source of radiation. It is a broadband electromagnetic source which, for the purposes of this introduction, only the visible spectrum is considered (approximately 390 to 750 nanometers or 400 to 769 TeraHertz). The source emits an incident field into the known background environment which, for this example, is free space. The incident field propagates until it strikes an object or target, either the yellow dog or the blue ball. The interaction of the incident field with an object results in a scattered field. The scattered field arises from a mis-match between the background refractive index, considered to be unity, and the scattering object refractive index ('yellow' for the case of the dog, and 'blue' for the ball). This is also known as an impedance mis-match. The scattering objects are referred to as secondary sources of radiation, that radiation being the scattered field which propagates until it is measured by the two receivers known as 'eyes'. The eyes focus the measured scattered field to form images which are processed by the 'wetware' of the brain for detection, identification, and localization. When time series representations of the measured scattered field are available, the image forming focusing process can be mathematically modeled by delayed, scaled, and summed migration. This concept of optical propagation, scattering, and focusing have one-to-one equivalents in the acoustic realm. This document is intended to present the basic concepts of scalar scattering and migration used in wide band wave-based remote sensing and imaging. The terms beamforming and (delayed, scaled, and summed) migration are used interchangeably but are to be distinguished from the narrow band (frequency domain) beamforming to determine the direction of arrival of a signal, and seismic migration in which wide band time series are shifted but not to form images per se. Section 3 presents a mostly graphically-based motivation and summary of delay, scale, and sum beamforming. The model for incident field propagation in free space is derived in Section 4 under specific assumptions. General object scattering is derived in Section 5 and simplified under the Born approximation in Section 6. The model of this section serves as the basis in the derivation of time-domain migration. The Foldy-Lax, full point scatterer scattering, method is derived in Section 7. With the previous forward models in hand, delay, scale, and sum beamforming is derived in Section 8. Finally, proof-of-principle experiments are present in Section 9.

Lehman, S K

2011-07-06

339

Individuals' openness to migrate and job mobility.  

Science.gov (United States)

In this article we extend the scope of the interdependence between migration and job mobility: We investigate whether an individual's openness to migrate not only increases the probability of migration but also the likelihood to conduct a job search and exhibit job mobility. Using data from a three-wave panel study, which allows the analysis of temporal links between decision-making and subsequent events regarding migration and job mobility, a joint estimation of multiple equations is performed. We show that considering migration as an option for the future, which is our indicator of individuals' openness to migrate, is positively associated with both migration and job mobility. It even increases job mobility independently of whether migration takes place or not. These findings contribute significantly to our body of knowledge about the interdependence of migration and job mobility. Additionally, they enhance our understanding of the mechanisms behind a common selectivity of migrants and job mobile individuals. PMID:24468430

Huinink, Johannes; Vidal, Sergi; Kley, Stefanie

2014-03-01

340

Migration, refugees, and health risks.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Migration both voluntary and forced is increasing all over the world. People are moving in larger numbers faster and further than at any other time in history. This is happening at a time when many countries are ill-prepared to deal with a changing demography and when policies and attitudes to population movement and immigration are hardening. The health implications of this are many, and, in some cases, illness and death rates associated with migration are exacerbated by a lack of policies n...

2001-01-01

 
 
 
 
341

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

1993-04-03

342

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

343

Evaluating the utility of hydrocarbons for Re-Os geochronology : establishing the timing of processes in petroleum ore systems  

Energy Technology Data Exchange (ETDEWEB)

Oil from 6 Alberta oil sands deposits were analyzed with a rhenium-osmium (Re-Os) isotope chronometer, an emerging tool for determining valuable age information on the timing of petroleum generation and migration. The tool uses molybdenite and other sulphide minerals to establish the timing and duration of mineralization. However, establishing the timing events of petroleum systems can be problematic because viable sulphides for the Re-Os chronometer are often not available. Therefore, the known presence of Re and Os associated with organic matter in black shale, a common source of hydrocarbons, may suggest that bitumen and petroleum common to petroleum systems may be utilised for Re-Os geochronology. This study evaluated the potential of the Re-Os isotopic system for geochronology and as an isotopic tracer for hydrocarbon systems. The evaluation was based on Re-Os isotopic analyses of bitumen and oil sands. Hydrocarbons formed from migrated oil in both Alberta oil sand deposits and a Paleozoic Mississippi Valley-type lead-zinc deposit contain significant Re and Os contents with high {sup 187}Re/{sup 188}Os and radiogenic {sup 187}Os/{sup 188}Os ratios suitable for geochronology. The oil from the 6 Alberta oil sand deposits yields Re-Os analyses with very high Re/{sup 188}Os ratios, and radiogenic Os isotopic compositions. Regression of the Re-Os data yields a date of 116 {+-} 27 Ma. This date plausibly represents the period of in situ radiogenic growth of {sup 187}Os following hydrocarbon migration and reservoir filling. Therefore, directly dating these processes, and this formation age corresponds with recent burial history models for parts of the Western Canada Sedimentary Basin. The very high initial {sup 187}Os/{sup 188}Os for this regression requires rocks much older than Cretaceous for the hydrocarbon source.

Selby, D.; Creaser, R.A. [Alberta Univ., Edmonton, AB (Canada). Dept. of Earth and Atmospheric Sciences

2005-07-01

344

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

345

Tritium dynamics within secondary contaminant sources in fractured shale bedrock  

Energy Technology Data Exchange (ETDEWEB)

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) define the importance of primary and secondary sources of tritium to contamination discharged to the streams along the perimeter of WAG 5.

Jardine, P.M.; Brooks, S.C.; Hicks, D.S.; Lu, B.W.; Sanford, W.E.; Reedy, O.C. [Oak Ridge National Laboratory, TN (United States)

1996-12-31

346

Supported catalyst for hydrocarbon synthesis  

Energy Technology Data Exchange (ETDEWEB)

Synthesis gas comprising hydrogen and CO can be converted to liquid hydrocarbons by using a catalyst comprising amounts of Co catalytically active in a Fischer-Tropsch synthesis and at least one loading-insensitive metal selected from the group consisting of Pt, Ir, and Rh composited on an alumina support. The finished catalyst exhibits a positive x-ray diffraction pattern having peaks in the 2{Theta} region of about 67-70{degree}, where {Theta} is the angle of refraction. The second metal is present in relatively lesser amounts than the Co content. The catalyst preferably contains ca 5-60 wt % Co and has a content of the second metal between ca 0.1 and 50 wt % of the Co content of the catalyst. The alumina is preferably {gamma}-alumina. It has been found that the addition of one or more of the metals from the Pt-Ir-Rh group to a predominantly Co-containing catalyst supported on alumina results in greatly enhanced activity for the conversion of synthesis gas to hydrocarbons. Experiments are described to illustrate the invention. 10 figs., 7 tabs.

Goodwin, J.G.; Marcelin, G.; Eri, S.; Riis, T.

1991-07-04

347

The UK Hydrocarbon Monitoring Networks  

Energy Technology Data Exchange (ETDEWEB)

National VOC monitoring in the United Kingdom is funded by the Department for Environment and Rural Affairs (defra) in conjunction with the National Assembly of Wales, the Department of Environment Northern Ireland and the Scottish Assembly. The monitoring network has recently undergone review and substantial restructuring. The first monitoring network was established in the mid 1990s and contained 13 fully automatic VOC monitors reporting hourly data on 26 hydrocarbon species continuously; these compounds included the two 'air toxics' benzene and 1,3 butadiene. Legislation in the UK required data, in the context of set air quality standards, on these two compounds to be made available for public information purposes. The network is described elsewhere; all of the data collected are available on the United Kingdom's Air Pollution Archive: http://www.airquality.co.uk/. After a period of approximately 10 years of operation, and over the last 2 years or so this network has been replaced by a second automatic network primarily developed to satisfy the requirements of the Benzene daughter Directive - the UK hydrocarbon network.

Dollard, G. [AEA Technology Environment, Abingdon, Oxfordshire (United Kingdom)

2004-07-01

348

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)

1970-05-01

349

Unsaturated medium hydrocarbons pollution evaluation  

International Nuclear Information System (INIS)

When the so called porous unsaturated medium, that's the vertical subsoil section between both the ground and water-table level, is interested by a hydrocarbons spill, the problem to evaluate the pollution becomes difficult: considering, essentially, the natural coexistence in it of two fluids, air and water, and the interactions between them. This paper reports that the problems tend to increase when a third fluid, the pollutant, immiscible with water, is introduced into the medium: a three-phases flow, which presents several analogies with the flow conditions present in an oil-reservoir, will be established. In such a situation, it would be very useful to handle the matter by the commonly used parameters in the oil reservoirs studies such as: residual saturation, relative permeability, phases mobility, to derive a first semiquantitative estimation of the pollution. The subsoil pollution form hydrocarbons agents is one of the worldwide more diffused causes of contamination: such events are generally referable to two main effects: accidental (oil pipeline breakdowns, e.g.), and continuous (underground tanks breaks, industrial plants leakages, e.g.)

1991-11-11

350

Hydrocarbon conversion process and catalysts  

Energy Technology Data Exchange (ETDEWEB)

This patent describes a process for hydrocracking hydrocarbon oils into products of lower average molecular weight and lower average boiling point. It comprises contacting hydrocarbon oil at a temperature between 250{sup 0}C and 500{sup 0}C and a pressure up to 300 bar in the presence of hydrogen with a catalyst consisting essentially of a Y zeolite modified to have a unit cell size below 24.40 A, a water adsorption capacity (at 25{sup 0}C and a rho/rho/sub o/ value of 0.2) of between 10% and 15% by weight of the zeolite and a pore volume of at least 0.25 ml/g wherein between 10% and 60% of the total pore volume is made up of pores having a diameter of at least 8 nm; am amorphous cracking component, a binder and at least one hydrogenation component selected from the group consisting of a Group VI metal, a Group VIII metal and mixtures thereof.

Hoek, A.; Huizinga, T.; Maxwell, I.E.

1989-08-15

351

Hydrocarbon degradation by antarctic bacteria  

Energy Technology Data Exchange (ETDEWEB)

Bacterial cultures obtained from sediment samples collected during a trial oil spill experiment conducted at Airport beach, Eastern Antarctica were selectively enriched for n-alkane-degrading and phenanthrenedegrading bacteria. Samples were collected from a control site and sites treated with different hydrocarbon mixtures - Special Antarctic blend (SAB), BP-Visco and orange roughy oils. One set of replicate sites was also treated with water from Organic Lake which had previously been shown to contain hydrocarbon-degrading bacteria. No viable bacteria were obtained from samples collected from sites treated with orange roughy oil. Extensive degradation of n-alkanes by enrichment cultures obtained from sites treated with SAB and BP-Visco occurred at both 25{degrees}C and 10{degrees}C. Extensive degradation of phenanthrene also occurred in enrichment cultures from these sites grown at 25{degrees}C. Concurrent increases of polar lipid in these cultures were also observed. The presence of 1,4-naphthaquinone and 1-naphthol during the growth of the cultures on phenanthrene is unusual and warrants further investigation of the mechanism of phenanthrene-degradation by these Antarctic bacteria.

Cavanagh, J.A.E.; Nichols, P.D.; McMeekin, T.A.; Franzmann, P.D. [Univ. of Tasmania (Australia)] [and others

1996-12-31

352

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

353

Methane and sulfur cycling in terrestrial hydrocarbon seeps  

Science.gov (United States)

Hydrocarbon seeps are ubiquitous in marine and terrestrial environments where gaseous fluids with unconsolidated, fine-grained sediments ascend along fractures prior to being discharged on seafloor or land surface. Complex geological and microbial processes are involved in the sequestration of photosynthetically produced organic carbon into deep subsurface environments and cycling of methane and carbon dioxide back to atmosphere. Extensive studies conducted on marine settings indicate that geochemical stratification in sediment porewater is dynamically regulated by various microbial processes. Whether the experience accumulated over the decadal observation on marine settings could be applied to shallow and deep biosphere beneath terrestrial hydrocarbon seeps remains poorly constrained. To address the issue about how carbon and sulfur compounds were cycled in terrestrial hydrocarbon seeps, this presentation summarized the results obtained from samples collected in two sites (one at 60C and the other at 27C) of southwestern Taiwan. These sites characterized by continuously voluminous discharge of hydrocarbons were considered as the model analogs that would provide better constraints on microbial processes at ambient and high temperatures in seep-related subsurface environments. Our findings indicated that sulfate reduction and methanogenesis were active at temperatures up to 80C. Sulfate reducing and fermentative populations shifted substantially upon incubations at different temperatures, suggesting that degradation of organic carbon could only proceed with collaborative interactions among metabolisms. The proliferation of mesophilic sulfate reduction in sulfate-deprived terrestrial environments appears to be best facilitated by atmospheric oxidation of pyrite inherited in sediments. Sulfate produced in surface environments migrated downward to fuel sulfate reduction coupled to anaerobic methane oxidation near the sulfate-to-methane transition. Of various methanogenic pathways, acetoclastic methanogenesis appears to fractionate carbon isotopes at a very small magnitude. This when combined with molecular results, field observations and mass balance calculation suggests that thermophilic methanogens produce thermogenesis-like methane at rates sufficiently high to account for the methane accumulation in deep, hot reservoirs. Thermogenic methane potentially overprinted by microbial methane at great depths was subject to further modification by methanogenesis and methane oxidation in sediments near surface. Overall, metabolic and geochemical stratification comparable with those in marine settings formed as the results of the interplay between the upward transport of gaseous, reduced, diluted fluids and the downward diffusion of oxidized, solute-enriched fluids. In contrary to marine settings, methane flux exceeds the capacity of microbial consumption, releasing methane directly to the atmosphere at quantities at least five orders of magnitude greater than those at the air-seawater interface.

Lin, L.; Wang, P.; Cheng, T.; Ling, Y.; Sun, C.; Chen, Y.; Wang, C.; Wu, J.; Chu, P.

2009-12-01

354

Hydrocarbon pneumonitis masquerading as acute lung injury  

Science.gov (United States)

Hydrocarbon pneumonitis is an acute, intense pneumonitis resulting from aspiration/inhalation of volatile hydrocarbon compounds with low viscosity and surface tension. The authors describe the case of a 24-year-old male who aspirated diesel while siphoning it from heavy duty crane, developed bilateral pneumonitis and responded to 2-day therapy with non-invasive continuous positive airway pressure ventilation.

Shrivastava, Makardhwaj Sarvadaman; Palkar, Atul Vijay; Karnik, Niteen D

2011-01-01

355

Conversion of organic solids to hydrocarbons  

Science.gov (United States)

A method of converting organic solids to liquid and gaseous hydrocarbons includes impregnating an organic solid with photosensitizing ions and exposing the impregnated solid to light in a non-oxidizing atmosphere for a time sufficient to photocatalytically reduce the solid to at least one of a liquid and a gaseous hydrocarbon.

Greenbaum, Elias (Oak Ridge, TN)

1995-01-01

356

An Easy Synthesis of Two Cage Hydrocarbons.  

Science.gov (United States)

Describes a simple, three-step synthesis of two cage molecules, birdcage hydrocarbon (VIII) and its homologue, the homobirdcage hydrocarbon IX. Indicates that all products are easily purified and formed in high yields in this activity suitable for advanced undergraduate laboratory courses. (Author/JN)

Dong, Dao Cong

1982-01-01

357

Contribution to radiolysis study of liquid hydrocarbons  

International Nuclear Information System (INIS)

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

1978-01-01

358

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

International Nuclear Information System (INIS)

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

2007-12-01

359

Near-surface hydrocarbon anomalies in shelf sediments off Spitsbergen: Evidences for past seepages  

Science.gov (United States)

As global warming occurs, the dissociation of bound methane on Arctic shelves due to ocean current temperature changes may become a major contributor to the global methane budget, and thus contribute to strong positive climate feedback mechanisms. However, little is known about the magnitude and fate of methane emissions from shallow submarine sediments to the atmosphere in the peculiar area. In this paper, we present one of the first direct evidences for seepage on the northwestern Barents Sea shelf. By studying the molecular and isotopic signatures of low-molecular-weight hydrocarbons in seawater, near-surface sediment pore space and the sediment matrix at 26 locations, we provide a detailed view on the partitioning of gaseous hydrocarbons in the sediment-water interface off Spitsbergen. In the free gas phase, low concentration of methane (˜28 ng/g wet Sediment) paired with constantly high isotopic values (˜-65‰) is consistent with high impact of methane oxidation on the isotopic composition. In contrast, high concentrations of adsorbed CH4 (up to 5292 ng/g wet seepages. Past upward flow of thermogenic gas and impregnation with mature hydrocarbons was particularly strong along tectonic lineaments. Active petroleum source rocks along the continental margin and migration of gaseous hydrocarbons at re-activated fault systems might explain the anomalies along these conduits.

Knies, Jochen; Damm, Ellen; Gutt, Julian; Mann, Ute; Pinturier, Laurence

2004-06-01

360

Clocks, cryptochromes and Monarch migrations  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

2009-01-01

 
 
 
 
361

Gas Migration Characteristics of Coalbeds.  

Science.gov (United States)

Drilling studies were conducted in the Pocahontas No. 3, the Pittsburgh, and a western coalbed to establish the gas migration characteristics for each. Gas pressures in the Pittsburgh coalbed were about 260 lb/sq. in and in excess of 550 lb/sq. in in the ...

J. D. Hadden A. Sainato

1969-01-01

362

International Migration and International Trade.  

Science.gov (United States)

The paper reviews the major types of international migration and recent global and regional trends in population movements, as well as conceptual issues and recent trends in the volume of remittance flows. The paper further considers the extent to which t...

S. S. Russell M. S. Teitelbaum

1992-01-01

363

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

1982-06-10

364

Recent WIPP brine migration experiments  

International Nuclear Information System (INIS)

Sandia laboratories has initiated some experiments to assess the mechanisms which influence the migration of fluids in rock salt. Two series of laboratory studies have been concluded recently, and plans for an initial in-situ experiment have been formulated. In addition, theoretical modeling studies are underway to provide formulations for predictions for both experiments and actual waste emplacements

1979-10-05

365

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

366

Planetary migration in protoplanetary disks  

CERN Multimedia

In the current paper, we further develop the model for the migration of planets introduced in Del Popolo et al. (2001) and extended to time-dependent accretion discs in Del Popolo and Eksi (2002). We use a method developed by Stepinski and Valageas (1996, 1997), that is able to simultaneously follow the evolution of gas and solid particles for up to $10^7 {\\rm yr}$. The disc model is coupled to the migration model introduced in Del Popolo et al. (2001) in order to obtain the migration rate of the planet in the planetesimal disc. We find that in the case of discs having total mass of $10^{-3}-0.1 M_{\\odot}$, and $0.1<\\alpha<0.0001$, planets can migrate inward a large distance while if $M<10^{-3} M_{\\odot}$ the planets remain almost in their initial position for $0.1<\\alpha<0.01$ and only in the case $\\alpha<0.001$ the planets move to a minimum value of orbital radius of $\\simeq 2 {\\rm AU}$. The model gives a good description of the observed distribution of planets in the period range 0-20 day...

Popolo, A D

2003-01-01

367

Hydrofining process for hydrocarbon containing feed streams  

Energy Technology Data Exchange (ETDEWEB)

A process is described for hydrofining a hydrocarbon-containing feed stream consisting of: introducing the reaction product of a mercaptoalcohol and a molybdenum compound selected from the group consisting of molybdic acids, alkali metal salts of molybdic acids and ammonium salts of molybdic acids into the hydrocarbon-containing feed stream, wherein a sufficient quantity of the reaction product is added to the hydrocarbon-containing feed stream to result in a concentration of molybdenum in said hydrocarbon-containing feed stream in the range of about 1 to about 60 ppm; and contacting the hydrocarbon-containing feed stream containing the reaction product under suitable hydrofining conditions with hydrogen and a catalyst composition comprising a support comprising a refractory material selected from the group consisting of alumina, silica and silica-alumina and a promoter comprising at least one metal selected from Group VIB, Group VIIB and Group VIII of the Periodic Table.

Kukes, S.G.; Hogan, R.J.; Coombs, D.M.; Efner, H.F.

1986-04-15

368

Removal of hydrocarbons from Nile water  

Energy Technology Data Exchange (ETDEWEB)

The need to remove hydrocarbons from water supply sources raises questions on the efficiency of the present water treatment processes in removing hydrocarbons. Therefore, the effectiveness of physicochemical processes involving chlorination, chemical coagulation and sand filtration were investigated. The effect of variable filtration media was also examined. In addition, the use of an activated carbon column was considered, and the effect of different retention times was evaluated. Results of this study showed that chemical coagulation using alum and Nalco removed only 32% of the total hydrocarbons and 80% of turbidity. Use of sand and a mixture of anthracite and sand filters showed additional removal of hydrocarbons and turbidity during the continuous filtration process. Increasing the anthracite depth relative to the total effective filtration depth increases the efficiency of the filter. Adsorption on granular activated carbon was shown to be an effective means for the removal of hydrocarbons. Results obtained indicated that the carbon adsorption capacity increases linearly as the retention time increases.

Moursy, A.S.; Abdel-Shafy, H.I.

1983-01-01

369

Secondary spectrum access networks  

DEFF Research Database (Denmark)

Some of the latest advancements made in the field of secondary spectrum access networks and spatial models are discussed. Dynamic spectrum access (DSA) has been proposed as a potential approach to improve spectrum utilization by allowing new wireless systems to dynamically access or share the licensed band on a negotiated or an opportunistic basis. DSA strategies can be broadly categorized into three models, such as dynamic exclusive use model, open sharing model, and hierarchical access model. The open sharing model allows peer users to have equal spectrum access rights and use a common spectrum without interfering with others, while the hierarchical access model adopts a hierarchical access structure with primary and secondary users. It allows the secondary users to access the licensed spectrum under the condition that no harmful interference is caused to the primary users.

Hong, X.; Wang, Xiongfei

2009-01-01

370

Pten deletion causes mTorc1-dependent ectopic neuroblast differentiation without causing uniform migration defects.  

Science.gov (United States)

Neuronal precursors, generated throughout life in the subventricular zone, migrate through the rostral migratory stream to the olfactory bulb where they differentiate into interneurons. We found that the PI3K-Akt-mTorc1 pathway is selectively inactivated in migrating neuroblasts in the subventricular zone and rostral migratory stream, and activated when these cells reach the olfactory bulb. Postnatal deletion of Pten caused aberrant activation of the PI3K-Akt-mTorc1 pathway and an enlarged subventricular zone and rostral migratory stream. This expansion was caused by premature termination of migration and differentiation of neuroblasts and was rescued by inhibition of mTorc1. This phenotype is reminiscent of lamination defects caused by Pten deletion in developing brain that were previously described as defective migration. However, live imaging in acute slices showed that Pten deletion did not cause a uniform defect in the mechanics of directional neuroblast migration. Instead, a subpopulation of Pten-null neuroblasts showed minimal movement and altered morphology associated with differentiation, whereas the remainder showed unimpeded directional migration towards the olfactory bulb. Therefore, migration defects of Pten-null neurons might be secondary to ectopic differentiation. PMID:22874917

Zhu, Guo; Chow, Lionel M L; Bayazitov, Ildar T; Tong, Yiai; Gilbertson, Richard J; Zakharenko, Stanislav S; Solecki, David J; Baker, Suzanne J

2012-09-01

371

Pten deletion causes mTorc1-dependent ectopic neuroblast differentiation without causing uniform migration defects  

Science.gov (United States)

Neuronal precursors, generated throughout life in the subventricular zone, migrate through the rostral migratory stream to the olfactory bulb where they differentiate into interneurons. We found that the PI3K-Akt-mTorc1 pathway is selectively inactivated in migrating neuroblasts in the subventricular zone and rostral migratory stream, and activated when these cells reach the olfactory bulb. Postnatal deletion of Pten caused aberrant activation of the PI3K-Akt-mTorc1 pathway and an enlarged subventricular zone and rostral migratory stream. This expansion was caused by premature termination of migration and differentiation of neuroblasts and was rescued by inhibition of mTorc1. This phenotype is reminiscent of lamination defects caused by Pten deletion in developing brain that were previously described as defective migration. However, live imaging in acute slices showed that Pten deletion did not cause a uniform defect in the mechanics of directional neuroblast migration. Instead, a subpopulation of Pten-null neuroblasts showed minimal movement and altered morphology associated with differentiation, whereas the remainder showed unimpeded directional migration towards the olfactory bulb. Therefore, migration defects of Pten-null neurons might be secondary to ectopic differentiation.

Zhu, Guo; Chow, Lionel M. L.; Bayazitov, Ildar T.; Tong, Yiai; Gilbertson, Richard J.; Zakharenko, Stanislav S.; Solecki, David J.; Baker, Suzanne J.

2012-01-01

372

Different reasons, different results: implications of migration by gender and family status.  

Science.gov (United States)

Previous research on migration and gendered career outcomes centers on couples and rarely examines the reason for the move. The implicit assumption is usually that households migrate in response to job opportunities. Based on a two-year panel from the Current Population Survey, this article uses stated reasons for geographic mobility to compare earnings outcomes among job migrants, family migrants, and quality-of-life migrants by gender and family status. We further assess the impact of migration on couples' internal household economy. The effects of job-related moves that we find are reduced substantially in the fixed-effects models, indicating strong selection effects. Married women who moved for family reasons experience significant and substantial earnings declines. Consistent with conventional models of migration, we find that household earnings and income and gender specialization increase following job migration. Married women who are secondary earners have increased odds of reducing their labor supply following migration for job or family reasons. However, we also find that migrating women who contributed as equals to the household economy before the move are no more likely than nonmigrant women to exit work or to work part-time. Equal breadwinner status may protect women from becoming tied movers. PMID:22109084

Geist, Claudia; McManus, Patricia A

2012-02-01

373

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

374

A Behavioral Model of Labor Force Migration.  

Science.gov (United States)

A model of inter-state out migration based upon the theoretical constructs of the human capital literature is empirically tested to ascertain the motivations for labor force migration. It is established that occupational mobility and geographic mobility a...

S. R. Nilsen

1976-01-01

375

Structural setting for hydrocarbons in the middle and upper Magdalena Basins, Colombia  

Energy Technology Data Exchange (ETDEWEB)

The structures hosting hydrocarbons in the Middle and Upper Magdalena Basins vary systematically in style and age along the length of this prolific Andean petroleum province. Variations in trap style and age are the result of the multiphase, but diachronous, evolution of the Northern Andes-a structurally complex [open quotes]orogenic float.[close quotes] The Magdalena Basins form a series of en echelon, sediment-filled structural depressions. Until the late Miocene, they had been parts of four extensive sub-Andean basins. The fourth basin structures were separate [open quotes]successor[close quotes] basins and reflect the separate frontal thrust systems forming the eastern margin of the Central Cordillera during the mid-Tertiary. The frontal thrust systems were arranged in an en echelon pattern younging southward. It was against this irregular thrust front of the Central Cordillera that the westward-directed thrusts of the Eastern Cordillera were molded in the late Miocene-Pliocene, resulting in widespread lateral ramping and displacement transfer within the basement-rooted thrust sheets. The interplay of structuring and syn-orogenic sedimentation has given rise to a multiplicity of scenarios for burial and maturation/migration of hydrocarbons from the underlying, organic-rich Cretaceous source rocks. Depending on location within the Magdalena Basins, entry into the oil generative window was as early as early Paleogene or as late as Recent. An understanding of the regional contrasts in structural trap style and age and in the timing of hydrocarbon generation/migration can aid the discovery of the remaining hydrocarbon resources of the Magdalena Basins.

Schamel, S. (Univ. of South Carolina, Columbia (United States))

1993-02-01

376

Improved carbon migration modelling with the ERO code  

International Nuclear Information System (INIS)

Material migration is a crucial issue in thermonuclear fusion devices. To study carbon migration, 13CH4 has been injected through a polished graphite roof-like test limiter in the TEXTOR scrape-off layer. The interpretation of the experimental 13C deposition patterns on the roof limiter surface has been done with the ERO impurity transport code. To reproduce the very low experimental 13C deposition efficiencies with ERO, an enhanced re-erosion mechanism for re-deposited carbon had to be assumed in previous studies. However, erosion by hydrogenic species produced during dissociation of injected 13CH4 was not taken into account by ERO in these studies. This additional erosion could maybe explain the very low experimental 13C deposition efficiencies. Therefore, it is now taken into account in ERO. Also more realistic physical sputtering yields and hydrocarbon reflection probabilities have been implemented in ERO. The simulations with these improvements included clearly confirm the need for enhanced re-erosion of re-deposited carbon

2013-07-01

377

[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

378

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

2010-05-01

379

Volatile hydrocarbons in pharmaceutical solutions  

Energy Technology Data Exchange (ETDEWEB)

Volatile pollutants such as hydrocarbons have, during many years, been analysed in small concentrations in air, water, food, pharmaceutical solutions, and human blood and tissues. It has also been shown that such substances have unexpected consequences for cell cultures and scientific experiments. These substances also accumulate in patients receiving haemodialysis and these patients are exposed to quite high concentrations. The knowledge of the toxicity of such compounds has led to the development of maximum limit concentrations with the aim to decrease the exposure of humans. This paper discusses the problems of human exposure in general and especially through pharmaceutical solutions, and the possibilities of eliminating such compounds with the aim of decreasing the exposure as a hygienic challenge.

Kroneld, R. (Department of Medicine, University of Turku (Finland))

1991-07-01

380

Hydrocarbons in the Mackenzie River  

Energy Technology Data Exchange (ETDEWEB)

Impaired fish liver quality has been reported on the lower Mackenzie River. This survey was part of a broader study of the possible impact on water quality by the Norman Wells area. A June, 1986 survey along the river found higher alkane and polyaromatic hydrocarbon (PAH) concentrations in the system than a similar survey in August 1985. The concentration distributions along the river suggested diffuse inputs of these organics by the spring runoff from the river's drainage basin, which overwhelmed any inputs from the refinery or from the oil seeps. The distribution of the organics between the suspended sediments and the water phase show the need for analyzing both phases for estimates of organic loadings in the river.

Nagy, E.; Carey, J.H.; Hart, J.H.; Ongley, E.D.

1987-01-01

 
 
 
 
381

Wakes in large hydrocarbon molecules  

International Nuclear Information System (INIS)

Electron capture-and-loss-to-the-continuum processes (ECC and ELC, respectively) for a fast projectile traversing atomic, molecular or solid targets produces a forward directed beam of electrons roughly velocity matched with projectile, i.e. v/sub e/ ? v/sub p/. These continuum electrons, detected at -- O/sup o/, form a cusp. Cups shapes for atomic gas and solid targets differ in their skewness and widths. There is also a difference in skewness, width and cross sections between ELC and ECC cusps for atomic (and molecular) gas targets. These cusp shape differences are a clue to the physical origin of the continuum electrons. In an attempt to understand the difference in cusp shapes between atomic and solid targets, the authors have bridged the gap by systematically varying target size, using hydrocarbon (C/sub m/H/sub n/) molecular gas targets ranging from m = 1 to m = 7. 11 references, 5 figures, 1 table

1986-04-01

382

Polycyclic aromatic hydrocarbons with SPICA  

CERN Document Server

Thanks to high sensitivity and angular resolution and broad spectral coverage, SPICA will offer a unique opportunity to better characterize the nature of polycyclic aromatic hydrocarbons (PAHs) and very small grains (VSGs), to better use them as probes of astrophysical environments. The angular resolution will enable to probe the chemical frontiers in the evolution process from VSGs to neutral PAHs, to ionized PAHs and to "Grand-PAHs" in photodissotiation regions and HII regions, as a function of G$_0$/n (UV radiation field / density). High sensitivity will favor the detection of the far-IR skeletal emission bands of PAHs, which provide specific fingerprints and could lead to the identification of individual PAHs. This overall characterization will allow to use PAH and VSG populations as tracers of physical conditions in spatially resolved protoplanetary disks and nearby galaxies (using mid-IR instruments), and in high redshift galaxies (using the far-IR instrument), thanks to the broad spectral coverage SPIC...

Berne, O; Mulas, G; Tielens, A G G M; Goicoechea, J R

2009-01-01

383

Aromatic hydrocarbons in interstellar space  

International Nuclear Information System (INIS)

After 1968 complex molecules of hydrocarbons were found in interstellar space. In the microwave range of the spectrum, the molecules show up by their rotation, in the infrared range by the vibration of their atoms. The occurrence of bands which are characteristic of the vibration of certain atom groups demonstrates their presence in the studied material. In interstellar dust polycyclic aromatic compounds are a frequent phenomenon, entering there from the outer mantles of stars which are cool and rich in carbon. Coronene seems to be the prevalent molecule judging by the evaluation of infrared emission spectra. The presence of these compounds was not yet unambiguously proved in interplanetary dust and meteorites. (M.D.). 1 fig

1988-01-01

384

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.)

1951-01-01

385

Aryl hydrocarbon receptor and colitis.  

Science.gov (United States)

The aryl hydrocarbon receptor (AhR), a transcription factor activated by a large variety of natural and synthetic ligands, has recently become the object of great interest among researchers since it represents an important link between environment and immune-mediated pathologies. In this context, evidence has been accumulated to show that AhR is necessary for the maintenance/expansion of intraepithelial lymphocytes and interleukin-22-producing innate lymphoid cells in the gut and that defects in AhR-delivered signals may contribute to amplify gut tissue destructive immune-inflammatory reactions. We here review the available data supporting the role of AhR in the control of immune homeostasis in the gut and discuss whether and how AhR activators can help dampen inflammatory processes. PMID:23928874

Monteleone, Ivan; Pallone, Francesco; Monteleone, Giovanni

2013-11-01

386

International Migration and its Effects on Family  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The crises period that still cross Romania explain, between others, the apparition and development of international migration, after 1990. In a world marked by globalization, migration can not disappear, contrary, it grows bigger ant it remains an interesting subject in future. A study about migration consequences on family, specially on children’s personality left in the country, is justified because migration is a present phenomena in Romanian space at the beginning of the XXIth century. ...

2008-01-01

387

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

2011-01-01

388

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

389

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

390

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

1994-01-01

391

Geochemical exploration for hydrocarbons - no new tricks - but an old dog  

Energy Technology Data Exchange (ETDEWEB)

Some mechanisms are described whereby light hydrocarbon gases, mainly methane, migrate vertically from high-pressure structural and stratigraphic reservoirs to near-surface soils. When soil samples are subjected to differential thermal analysis, the carbon dioxide evolving therefrom is referred to as /DELTA/C, which usually appears in the form of a geochemical halo in the soil around the oil and gas fields. Three case histories are presented indicating the classic geochemical halo pattern overlying three different types of producing fields. 6 refs.

Duchscherer, W. Jr.

1982-07-05

392

Modernising Portugal's Secondary Schools  

Science.gov (United States)

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

Heitor, Teresa V.

2008-01-01

393

???: Consensus Secondary Structure Prediction  

Full Text Available 09000 09200 ????????????????? | ??????????? Consensus Secondary Stru ????????????????WEB???? SOPM?SOPMA?HNN ?MLRC

394

From Primary to Secondary  

Science.gov (United States)

This author discusses her decision to move to secondary school to teach mathematics, after having taught and been a mathematics manager in primary schools for six years. She states that this was a valuable experience and sparked her interest in the transition experiences of students, particularly in mathematics. Research (Evangelou et al, 2008,…

Anderson, Lyn

2011-01-01