WorldWideScience
1

GIS-based modeling of secondary hydrocarbon migration pathways and its application in the northern Songliao Basin, northeast China  

Science.gov (United States)

Hydrocarbon migration pathways are the linkage between hydrocarbon source areas and accumulation sites. Modeling accurately the pathways of hydrocarbon migration is of important significance in determining the location of favorable petroleum exploration targets. In this paper, GIS-based modeling algorithms are presented for searching the pathways of secondary hydrocarbon migration by considering the geologic mechanisms. These algorithms are constructed on a raster digital elevation model (DEM) of the top boundary of a carrier bed, in which secondary migration occurred. On the DEM, a 3×3 pixel sized window is used for searching. The center of the search window is initially assumed at a point on the boundary of a hydrocarbon source area, from which the secondary hydrocarbon migration starts. The altitude values in the eight adjoining pixels enclosing the central pixel of the search window are compared, and the pixel with an altitude value not only larger than the central pixel but also the largest of the eight surrounding pixels is the next target pixel where the search window will move to. Each searched path will terminate at either a convex point, which indicates the existence of a trap for hydrocarbon accumulation, or a point on the boundary of the DEM, which suggests that the pathway of hydrocarbon migration extends outside the DEM. In addition, a concourse point of two paths is also considered as a termination point of either path. The algorithms were successfully applied in the modeling of the secondary migration pathways in the northern Songliao Basin, northeast China. The modeled results matched well with drilling data, suggesting the robustness of the algorithms.

Liu, Xuefeng; Zhong, Guangfa; Yin, Jingyuan; He, Youbin; Li, Xianhua

2008-09-01

2

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

Directory of Open Access Journals (Sweden)

Full Text Available

By using a finite volume method as a solver, a modified 3-D 3-phase (water, oil, gas black-oil model for modeling hydrocarbon (HC secondary migration in the context of basin modeling is presented in this paper. The model predicts the quantity and distribution of HC accumulation in space and time. The black-oil model used in basin modeling is more complex and more difficult to model than that in reservoir simulations, as the model includes variable simulation ranges, very long simulation times, initial conditions, natural sources and sinks, and reservoir gridcells. In the proposed finite volume formulation, the gridding of variable 3-D geological volumes is performed using perpendicular bisection (PEBI gridcells, which makes the discretization and subsequent implementation of 3-phase flow equations much easier than when using hexahedral or tetrahedral gridcells. The stability and convergence of the solutions have been improved by using finite volumes with PEBI gridcells and the fully implicit formulation. A detailed case study in the Kuqa Depression of the Tarim Basin in western China shows that the simulation results and predictions agree well with field evaluations.

Key words: Basin modeling; Secondary migration; Black-oil model; Finite volume method; PEBI gridding; Kuqa Depression

SHI Guangren

2011-10-01

3

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

International Nuclear Information System (INIS)

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

4

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

Science.gov (United States)

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

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

2015-02-01

5

Arsenic cycling in hydrocarbon plumes: secondary effects of natural attenuation  

Science.gov (United States)

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

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

2015-01-01

6

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

7

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

8

Evolution of hydrocarbon migration style in a fractured reservoir deduced from fluid inclusion data, Clair Field, west of Shetland, UK  

Energy Technology Data Exchange (ETDEWEB)

A petrographic and fluid inclusion microthermometric study was performed on sandstones from the Devonian-Carboniferous reservoir rocks of the Clair Field, west of Shetland. Fluid inclusion petrographic and microthermometric observations were collected from quartz, K-feldspar and calcite cements and veins. Vein and cement minerals host both aqueous and hydrocarbon two-phase (liquid and vapor-filled) fluid inclusions indicating that cementation occurred during oil charging. The location of hydrocarbon fluid inclusions in the paragenetic sequence of the reservoir rocks indicates that hydrocarbon migration during early-stage diagenesis occurred via intergranular pores as well as fractures, whereas towards the later stages of diagenesis, as porosities were occluded, hydrocarbon migration was predominantly fracture controlled. The microthermometric characteristics of primary and secondary aqueous fluid inclusions in association with hydrocarbon fluid inclusions indicates that cementation and veining during oil charging occurred at temperatures up to 180 C. Salinity values are variable (0-10.9 wt% NaCl eq.) indicating that fluid mixing occurred during veining and cementation. Basin modeling and vitrinite reflectance data indicate that temperatures of up to 180 C could not have been attained through burial alone. The high temperatures attained during late-stage diagenesis are interpreted to be caused by high temperature, short-lived fluids circulating within the Devonian-Carboniferous reservoir rocks in association with late Cretaceous and Paleocene magmatism. These high temperature fluid flow events were not recorded in the vitrinite reflectance data because of their short duration. (author)

Baron, Martin; Parnell, John; Mark, Darren [Department of Geology and Petroleum Geology, Meston Building, University of Aberdeen, King' s College, Aberdeen AB24 3UE (United Kingdom); Carr, Andrew [Advanced Geochemical Systems Ltd., Towles Fields, Burton on the Wolds, Leicestershire LE12 5TD (United Kingdom); British Geological Survey, Keyworth, Nottingham NG12 5GG (United Kingdom); Przyjalgowski, Milosz [Department of Physics, National University of Ireland-Galway, Galway (Ireland); Feely, Martin [Department of Geology, National University of Ireland-Galway, Galway (Ireland)

2008-02-15

9

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

OpenAIRE

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

10

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

11

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

12

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

Science.gov (United States)

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

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

2009-01-01

13

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

CERN Document Server

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

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

2011-01-01

14

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

15

Hydrocarbon gases at eastern Mediterranean mud expulsion structures: origin, migration, and water column expression  

Science.gov (United States)

In the eastern Mediterranean a variety of different mud expulsion structures is found on the seafloor at passive and continental margins, all of which appear to have active emission of hydrocarbon gases. The eruptions are thought to be triggered by the overpressure occurring at depth and resulting from excess gas and water pressure. Gas, fluids, and sediments are then mobilized and migrate through the sedimentary column (often via faults), building mud domes. At all mud structures investigated in the eastern Mediterranean, not only enhanced concentrations of methane, but also of ethane, and propane, have been observed in the sediment, and in the water column. The water column gas plumes extend up to several hundreds of meters above the seafloor and even reach the sea surface. These gas plumes are associated with enhanced light scattering, which can be associated to the release of gas bubbles and/or sedimentary particles. Part of the hydrocarbons may have been altered by (microbial) oxidation. The signature of the gases that resembles most the initial composition can be found in the deepest core samples. Several of the water column plumes closely resemble these, thereby confirming their direct emission via bubble transport into the water column. On the basis of gas concentrations and isotope composition, a thermogenic origin with a smaller but variable biogenic contribution can be deduced for the hydrocarbon gases at most mud expulsion structures. This work has been supported by the EUROMARGINS Programme of the European Science Foundation NWO. 85501032 Mediflux project).

Mastalerz, V.; de Lange, G. J.; Daehlmann, A.

2009-04-01

16

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

Energy Technology Data Exchange (ETDEWEB)

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

Wagner, G.

1997-12-31

17

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

18

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.)

19

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

20

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

OpenAIRE

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

21

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

Energy Technology Data Exchange (ETDEWEB)

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

Wagner, G.

1997-09-01

22

Hydrocarbonization  

Energy Technology Data Exchange (ETDEWEB)

Hydrocarbonization or low temperature carbonization under hydrogen pressure is representative of a class of coal conversion processes distinctly different from the slurry hydroliquefaction processes and processes which synthesize liquid fuels from coal-derived synthesis gas. Hydrocarbonization technology is reviewed and major process alternatives and problem areas are discussed. The present status and future prospects for hydrocarbonization are assessed.

Cochran, Jr., H. D.

1979-01-01

23

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

24

Mass spectrometric study of secondary organic aerosol formed from the photo-oxidation of aromatic hydrocarbons  

Science.gov (United States)

From measurements by an Aerodyne Aerosol Mass Spectrometer (AMS), secondary organic aerosol (SOA) formed in laboratory chambers is believed to be less oxidized than well-oxidized ambient organic aerosol (OA). However, the mass spectrum of SOA formed from the photo-oxidation of aromatic hydrocarbons has not been sufficiently studied by using AMS though these reactions are potential sources of urban SOA. In this study, we studied SOA formed from the photo-oxidation of seven aromatic hydrocarbons by using Time-of-Flight AMS. Strong mass signals from SOA were found at m/ z 43 (m43) and 44 (m44) in all the experiments. The m44 to total organic aerosol mass ratio (m44/OA) increased with irradiation time. For example, the m44/OA ratio increased from 10.6% to 13.3% during irradiation for 11 h in an experiment with toluene. The average m44/OA ratios were determined to be 5.8-17.1% for all the experiments. The m44/OA decreased and the m43/OA increased with increasing number of alkyl substituents of precursor aromatic hydrocarbons. This is because low-reactive ketones are preferentially produced rather than aldehydes with increasing number of alkyl substituents. The m44/OA ratios of the benzene and monoalkylbenzene oxidation were 12.2-17.1% and were close to those of well-oxidized ambient OA. These findings are consistent with the hypothesis that the photo-oxidation of aromatic hydrocarbons is a potential source of urban SOA. In addition to oxygenated organic compounds, organic nitrogen oxides were also shown to be present in SOA by high-resolution mass spectra.

Sato, Kei; Takami, Akinori; Isozaki, Tasuku; Hikida, Toshihide; Shimono, Akio; Imamura, Takashi

2010-03-01

25

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

26

Hydrocarbon formation and migration in the volcanic Møre and Vøring basins offshore Norway  

Science.gov (United States)

Voluminous igneous sheet intrusions were emplaced in low quality Cretaceous source rocks in the Vøring and Møre basins offshore Norway about 55.8 million years ago. We show that several hundred gigatons of carbon gas can be formed as a result of contact metamorphism in the basin during the intrusive event based on studies of borehole data and numerical modeling. The numerical modeling further shows that multiple sill intrusions emplaced at the same time increase the gas generation potential by up to 35 % relative to intrusions emplaced sequentially. The gas migrated out of the aureoles by two mechanisms. (1) The major gas release occurred immediately after the gas was generated through thousands of hydrothermal vent complexes, and may have caused disruption in the global carbon cycle triggering the Paleocene-Eocene thermal maximum (PETM). (2) The second mechanism involves slow gas seepage, occasionally to the seafloor, in the Eocene to the Paleogene forming seep carbonates and hydrocarbon deposits. In addition, significant volumes of aureole gas (dry gas and CO2-rich gas) are still likely trapped in the source rocks as shale gas. Our results are important to understand petroleum systems in volcanic basins and the cause of rapid climate changes and mass extinctions in Earth history.

Planke, S.; Aarnes, I.; Svensen, H.; Polteau, S.

2010-12-01

27

Frio formation of the Texas Gulf Coast basin - depositional systems, structural framework, and hydrocarbon origin, migration, distribution, and exploration potential  

Energy Technology Data Exchange (ETDEWEB)

The Frio Formation is one of the major Tertiary progradational wedges of the Texas Gulf Coast basin and has yielded nearly 6 billion bbl of oil and 60 trillion cu ft of gas. The Frio and its updip equivalent, the Catahoula Formation, consist of deposits of 2 large fluvial and associated deltaic systems. All Frio depositional systems contain economically significant, geologically defined hydrocarbon-producing plays. Volume, production style, and type of hydrocarbon within each of 10 recognized plays reflect source-rock quality and type, differing compaction and pore-fluid-migration history, and reservoir and trap configurations characteristic of each depositional system. Analysis of volumetric, historic, and geologic relationships for production and discovery within each play provides a basis for estimating the undiscovered hydrocarbon resource potential as well as for assigning that potential to specific geographic and stratigraphic subdivisions of the depositional basin. 76 references.

Galloway, W.E.; Hobday, D.K.; Magara, K.

1982-01-01

28

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

Science.gov (United States)

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

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

2010-08-01

29

Modeling potential migration of petroleum hydrocarbons from a mixed-waste disposal site in the vadose zone  

International Nuclear Information System (INIS)

Environmental monitoring of a mixed-waste disposal site at the Idaho National Engineering Laboratory has confirmed release and migration into the vadose zone of: (1) chlorinated hydrocarbons in the vapor phase and (2) trace levels of certain transuranic elements. The finding has prompted an evaluation of the potential role of waste petroleum hydrocarbons in mediating or influencing contaminant migration from the disposal site. Disposal records indicate that a large volume of machine oil contaminated with transuranic isotopes was disposed at the site along with the chlorinated solvents and other radioactive wastes. A multiphase flow model was used to assess the possible extent of oil and vapor movement through the 177 m thick vadose zone. One dimensional simulations were performed to estimate the vertical distribution of the vapor phase, the aqueous phase, and immiscible free liquid as a function of time. The simulations indicate that the oil may migrate slowly through the vadose zone, to potentially significant depths. Calculated transport rates support the following ranking with regard to relative mobility: vapor phase > aqueous phase > free liquid. 21 refs., 7 figs., 2 tabs

30

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

Science.gov (United States)

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

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

2004-01-01

31

Spatial variations in magnetic properties in three reservoirs of the Western Canada Sedimentary Basin : insights into hydrocarbon generation and migration  

Energy Technology Data Exchange (ETDEWEB)

Some of the possible applications of paleomagnetism and rock magnetism in the petroleum industry were discussed. It has been shown that paleomagnetic and rock magnetic data can be used to track and map fluid migration. A study was conducted in 1997 in which limestones, dolostones and anhydrites of the Mississippian Upper Debolt Formation in the Dunvegan, Cindy and Belloy fields in the Western Canada Sedimentary Basin were sampled for rock magnetic, paleomagnetic, petrological and geochemical analysis. It was determined that, contrary to expectations, there was a significant spatial variation in the paleomagnetic and rock magnetic data. Analysis of about 300 specimens indicated the presence of three components: (1) a low temperature or low coercivity `A` component, removed at temperatures of less than 250 degrees C and coercivities of less than 20 mT, (2) the `B` component removed at temperatures between 250 and 350 degrees C and AF fields between 20 and 80 mT, and (3) the `C` component, a high temperature or high coercivity component removed at temperatures above 350 degrees C and fields above 20 mT. The spatial variation in paleomagnetic and rock magnetic properties has important implications for fluid migration, fluid migration pathways, and possible hydrocarbon sources. 3 refs.

Cioppa, M.T.; Symons, D.T.A. [Windsor Univ., Dept. of Earth Sciences, Windsor, ON (Canada); Gillen, K.P. [Vox Terrae International, Calgary, AB (Canada)

1999-11-01

32

SATURATED AND AROMATIC MINERAL OIL HYDROCARBONS FROM PAPERBOARD FOOD PACKAGING: ESTIMATION OF LONG-TERM MIGRATION FROM CONTENTS IN THE PAPERBOARD & DATA ON BOXES FROM THE MARKET  

OpenAIRE

Abstract In the absence of a functional barrier, mineral oil hydrocarbons from printing inks and recycled fibers tend to migrate from paper-based food packaging materials through the gas phase into dry food. Concentrations easily far exceed the limit derived from the Acceptable Daily Intake (ADI) of the Joint FAO/WHO Expert Committee on Food Additives (JECFA). Since estimation of long-term migration into the food by testing at 40°C for 10 days is difficult, it seems preferable (an...

Lorenzini, Rita; Fiselier, Katel; Biedermann, Maurus; Barbanera, Martino; Braschi, Ilaria; Grob, Konrad

2010-01-01

33

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

Science.gov (United States)

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

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

2014-10-01

34

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

Energy Technology Data Exchange (ETDEWEB)

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

Kushnirov, V.V.

1981-01-01

35

Petroleum Weathering Associated with Hydrocarbon Migration and Seepage, a Case Study From the Santa Barbara Channel, CA.  

Science.gov (United States)

A 2003 report by the National Research Council estimates that 50 to 70 percent of oil that is released into the sea is from natural seeps (National Research Council, 2003), indicating that catastrophic oil spills or the runoff from roads and highways are not the major sources of oil in the marine environment. For example, approximately 37 tons of petroleum is emitted daily from seeps off the coast of Santa Barbara, California (Quigley et al. 1996). The Santa Barbara seeps are some of the most active in the world and have been releasing petroleum for thousands of years. Sheens of oil on the water surface and tar patches on the beaches are ubiquitous along the coastline of Santa Barbara and are continuing reminders of this natural process. Although the geochemistry of these seeps have been studied in the past, it has been hindered by the complexity of the petroleum hydrocarbons and the inability of traditional gas chromatography to separate, identify, and quantify each component of the oil. To expand on these previous efforts, we have begun to use comprehensive two-dimensional gas chromatography (GCxGC). This new technology provides at least an order of magnitude increase in the resolution and detection of petroleum hydrocarbons compared to traditional methods. Preliminary work using GCxGC has focused on examining the chemical composition of unrefined petroleum as it migrates up from depth through natural faults to the seafloor, from the seafloor to the sea surface, and from the sea surface to local beaches. Petroleum collected from a subsurface reservoir (Platform Holly Well 2342-15) is composed of a wide range of resolved petroleum hydrocarbons including n-alkanes, branched alkanes, cycloalkanes, linear alkane benzenes, polycyclic aromatic hydrocarbons, steranes, hopanes, cyclic isoprenoids, and very large branched biomarkers with 38 to 40 carbons. This product is significantly different than oil emerging from the seafloor at the Jackpot seep, which we believe is due to biodegradation. Alternatively, direct comparisons of the latter to samples collected on the sea surface show extensive losses of light-end components due to evaporation and not water washing. Tar balls collected from nearby beaches appear to be the end result of biodegradation, evaporation, and water washing of the original material seeping from the ocean floor. These initial studies reveal that the geochemistry and processes acting on petroleum seeping from the ocean floor are complex. Efforts are underway to construct accurate models that will quantify each environmental process that affects the fate of petroleum in the marine environment.

Wardlaw, G. D.; Nelson, R. K.; Reddy, C. M.; Valentine, D. L.

2005-12-01

36

Saturated and aromatic mineral oil hydrocarbons from paperboard food packaging: estimation of long-term migration from contents in the paperboard and data on boxes from the market.  

Science.gov (United States)

In the absence of a functional barrier, mineral oil hydrocarbons from printing inks and recycled fibres tend to migrate from paper-based food-packaging materials through the gas phase into dry food. Concentrations easily far exceed the limit derived from the acceptable daily intake (ADI) of the Joint FAO/WHO Expert Committee on Food Additives (JECFA). Since the estimation of long-term migration into the food by testing at 40°C for 10 days is difficult, it seems preferable (and easier) to use the mineral oil content in the paperboard. Evaporation experiments showed that hydrocarbons eluted up to about n-C?? are sufficiently volatile for relevant migration into dry food: in worst-case situations, about 80% migrate into the packed food. The extraction of the paperboard was optimised to give good recovery of the relevant hydrocarbons, but to discriminate against those of high molecular mass which tend to disturb gas chromatographic analysis in on-line coupled normal phase HPLC-GC-FID. Even though some of the relevant hydrocarbons had already evaporated, the average concentration of oil saturated hydrocarbons (MOSH) in the paperboard boxes of 102 products from the Swiss and Italian market was 626 mg kg?¹. Nearly 15% of investigated boxes still contained more than 1000 mg kg?¹ < C?? MOSH up to over 3000 mg kg?¹ (maximum = 3500 mg kg?¹). This amount of MOSH in the board have the potential of contaminating the packed food at a level exceeding the limit, derived from the JECFA ADI, hundreds of times. PMID:20967663

Lorenzini, R; Fiselier, K; Biedermann, M; Barbanera, M; Braschi, I; Grob, K

2010-12-01

37

Microstructures in the Cretaceous Bima Sandstone, Upper Benue Trough, N.E. Nigeria: Implication for hydrocarbon migration  

Science.gov (United States)

Faulting related to movements along major fault zones in the Upper Benue Trough during Albian times, with evidence of deformation in the Cretaceous Bima Sandstone are common especially around the Kaltungo, Gombe, Zambuk and Teli lineaments. Conjugate extensional systems of deformation bands show increased siliceous cementation of the sandstones adjacent to these lineaments. During the Late Cretaceous compressional event, the deformation bands and faults in the Upper Benue Trough were reactivated, resulting into dilational opening of fractures believed to have acted as fluid conduits and/or barriers. These deformation bands which decrease in density away from the major faults are characterized with increasing porosity and permeability in the host sandstone abruptly away from the tectonic barrier. It is proposed here that the master faults of the Benue Trough, linking it with the Anambra Basin and the Niger Delta probably served as conduits for the migration of hydrocarbons into the Cretaceous reservoirs of the Upper Benue Trough and by extension into the Niger Delta.

Samaila, N. K.; Dike, E. F. C.; Obaje, N. G.

2008-01-01

38

Nanocarrier-mediated inhibition of macrophage migration inhibitory factor attenuates secondary injury after spinal cord injury.  

Science.gov (United States)

Spinal cord injury (SCI) can lead to permanent motor and sensory deficits. Following the initial traumatic insult, secondary injury mechanisms characterized by persistent heightened inflammation are initiated and lead to continued and pervasive cell death and tissue damage. Anti-inflammatory drugs such as methylprednisolone (MP) used clinically have ambiguous benefits with debilitating side effects. Typically, these drugs are administered systemically at high doses, resulting in toxicity and paradoxically increased inflammation. Furthermore, these drugs have a small time window postinjury (few hours) during which they need to be infused to be effective. As an alternative to MP, we investigated the effect of a small molecule inhibitor (Chicago sky blue, CSB) of macrophage migration inhibitory factor (MIF) for treating SCI. The pleiotropic cytokine MIF is known to contribute to upregulation of several pro-inflammatory cytokines in various disease and injury states. In vitro, CSB administration alleviated endotoxin-mediated inflammation in primary microglia and macrophages. Nanocarriers such as liposomes can potentially alleviate systemic side effects of high-dose therapy by enabling site-specific drug delivery to the spinal cord. However, the therapeutic window of 100 nm scale nanoparticle localization to the spinal cord after contusion injury is not fully known. Thus, we first investigated the ability of nanocarriers of different sizes to localize to the injured spinal cord up to 2 weeks postinjury. Results from the study showed that nanocarriers as large as 200 nm in diameter could extravasate into the injured spinal cord up to 96 h postinjury. We then formulated nanocarriers (liposomes) encapsulating CSB and administered them intravenously 48 h postinjury, within the previously determined 96 h therapeutic window. In vivo, in this clinically relevant contusion injury model in rats, CSB administration led to preservation of vascular and white matter integrity, improved wound healing, and an increase in levels of arginase and other transcripts indicative of a resolution phase of wound healing. This study demonstrates the potential of MIF inhibition in SCI and the utility of nanocarrier-mediated drug delivery selectively to the injured cord. PMID:25587936

Saxena, Tarun; Loomis, Kristin H; Pai, S Balakrishna; Karumbaiah, Lohitash; Gaupp, Eric; Patil, Ketki; Patkar, Radhika; Bellamkonda, Ravi V

2015-02-24

39

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  

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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

40

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

Energy Technology Data Exchange (ETDEWEB)

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

Liao, Y.H.; Geng, A.S. [Chinese Academy of Sciences, Ghangzhou (China). Guangzhou Institute of Geochemistry

2009-11-15

41

[Cholangitis secondary to migrated metallic coils in the common bile duct].  

Science.gov (United States)

Biliary obstructions are infrequently caused by foreign bodies. We present an unusual case of angiographically placed metallic coils into the intrahepatic arteries to provide hemostasis, that subsequently eroded into the common bile duct leading to obstructive jaundice and cholangitis a year later. In patients with history of invasive procedures, the possibility of foreign body migration into the common bile duct should always be considered in the differential diagnosis of obstructive jaundice and cholangitis. PMID:23940918

Zervos, Xaralambos; Molina, Enrique; Larsen, Marcelo Fabián

2013-06-01

42

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

International Nuclear Information System (INIS)

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

43

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

44

Secondary aerosol formation from the oxidation of biogenic hydrocarbons by chlorine atoms  

Science.gov (United States)

The chlorine atom (Cl) is a potential oxidant of volatile organic compounds (VOCs) in the atmosphere and is hypothesized to lead to secondary organic aerosol (SOA) formation in coastal and industrialized areas. The purpose of this paper is to test this hypothesis and to quantify the SOA formation potentials of the common monoterpenes ?-pinene, ?-pinene, and d-limonene when oxidized by Cl in laboratory chamber experiments. Results indicate that the oxidation of these monoterpenes generates significant amounts of aerosol. The SOA yields of ?-pinene, ?-pinene, and d-limonene in this study are comparable to those when they are oxidized by ozone, by nitrate radical, and in photooxidation scenarios. For aerosol mass up to 30.0 ?g m-3, their yields reach approximately 0.20, 0.20, and 0.30, respectively. For d-limonene, data indicate two yield curves that depend on the initial concentration ratio of Cl precursor to d-limonene. It is argued theoretically that multiple SOA yield curves may be common for VOCs, depending on the initial concentration ratio of oxidant to VOC. SOA formation from the three typical monoterpenes when oxidized by Cl in the marine boundary layer, coastal areas, and inland industrialized areas could be a source of organic aerosol in the early morning.

Cai, Xuyi; Griffin, Robert J.

2006-07-01

45

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

Directory of Open Access Journals (Sweden)

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

D. K. Henze

2007-10-01

46

Origin and Migration of Oil: Oil may consist of hydrocarbons that collected from waters containing natural solubilizers.  

Science.gov (United States)

A relationship exists between the composition of crude oil and the solubility of the component hydrocarbons in dilute colloidal electrolyte solutions, suggesting that crude oil consists of hydrocarbons that were once solubilized in formation waters. It is not solubility in ordinary water or solubility in complete soap solution that correlates with the composition of oil but, rather, solubility in soap micelles. Because it implies a possible unloading mechanism, this concept is attractive, for it follows that when a soap solution is diluted with water, the soap micelles disperse and the hydrocarbons solubilized therein appear as discrete, filterable oil droplets. Thus, it would seem that crude oil originates during the compaction of a sedimentary basin by virtue of the fact that sediment hydrocarbons dissolve in waters containing natural solubilizers and then come out of solution as oil droplets. The composition of crude oil as now understood is consistent with this hypothesis. And-most important-it is now possible to formulate meaningful questions, the answers to which, upon investigation in both field and laboratory, will go far toward enabling us to assess the validity of the mechanism presented here. In addition to the implications regarding the composition of crude oil that are inherent in the hypothesis that crude oil collects from aqueous colloidal electrolyte solutions, there are several interesting implications from the geological viewpoint. To mention one, such a mechanism would lend credence to the suggestion that the source beds of petroleum are not necessarily unique accumulations of hydrocarbons in a limited area but, rather, may generally be coincident with the area from which water is expressed into the porous strata that eventually form the reservoirs. PMID:17830833

Baker, E G

1959-04-01

47

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

Scientific Electronic Library Online (English)

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

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

2013-02-01

48

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

Science.gov (United States)

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

Webb, Sue

2015-01-01

49

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

OpenAIRE

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

Secondary ion mass spectroscopy study of Au trapping and migration in the Au-irradiated YBa2Cu3O7 - delta film  

Science.gov (United States)

The range data and migration of Au in YBa2Cu3O7-? film were studied with implanted 197Au (1.5 MeV 5×1015 Au+/cm2) as a tracer. The film was a c-axis oriented film, ˜750 nm thick, deposited by high-pressure planar dc sputtering on LaAlO3. Analysis by secondary ion mass spectroscopy shows that the as-implanted Au concentration distribution is essentially Gaussian-like and the depth (R?p) of maximum Au concentration (˜1.2 wt %) is 201 nm. The projected range (R¯p) and (R?p) are found to be in very good agreement with the simulated data by TRIM-95, whereas the measured ``straggle'' (?Rp*) is about 20% larger than that by TRIM-95 simulation. It has also been found that the implanted 197Au starts to migrate within the film at a temperature between 650 and 700 °C, which is much higher than that for the implanted 2H (˜175 °C) and the implanted 18O (between 250 and 300 °C) in c-oriented YBa2Cu3O7-? films.

Li, Yupu; Kilner, J. A.; Liu, J. R.; Chu, W. K.; Wagner, G. A.; Somekh, R. E.

1996-05-01

51

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

Science.gov (United States)

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

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

2005-08-01

52

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2005-12-15

53

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

Scientific Electronic Library Online (English)

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

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

2008-06-01

54

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

Czech Academy of Sciences Publication Activity Database

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

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

2010-01-01

55

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

Science.gov (United States)

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

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

2012-03-01

56

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2013-11-15

57

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

International Nuclear Information System (INIS)

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

58

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

Science.gov (United States)

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

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

2005-12-01

59

The presence of hydrocarbons in southeast Norway  

DEFF Research Database (Denmark)

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

Hanken, Niels Martin; Hansen, Malene Dolberg

60

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

61

Hydrocarbon Accumulation and Distribution Characteristics of the Silurian in the Tazhong Uplift of Tarim Basin  

Science.gov (United States)

Hydrocarbon accumulation of the Silurian in the Tazhong uplift of Tarim basin is characterized by "two sources and three stages". "Two sources" means that the hydrocarbons are derived from two source rocks of the Cambrian and Middle-Upper Ordovician. "Three stages" means that asphalt and movable oil undergoes three hydrocarbon accumulation stages, i.e., Late Caledonian, Late Hercynian, and Yanshanian-Himalayan. The formation of asphalt resulted from the destruction of the hydrocarbons accumulated and migrated in the early stages. The present movable oil, mostly derived from Middle-Upper Ordovician source rock, resulted from the hydrocarbons accumulated in the late stage. There are three types of reservoirs, i.e., anticline structural, stratigraphic lithological, and lava shield reservoirs in the Tazhong uplift. Hydrocarbon accumulation of the Silurian in the Tazhong uplift is controlled by the three factors. (1) The background of uplift structure. Around the ancient uplift, the compounding of many types makes up the composite hydrocarbon accumulation areas. (2) Effective cover. The show of oil gas including asphalt, heavy crude oil, and normal oil is quite active in the Silurian. Asphalt and heavy crude oil are distributed under the red mudstone member and movable oil is distributed under the gray mudstone member. (3) High quality reservoir bed. Sandstone is distributed widely in the Tazhong area. Reservoir pore space can be divided into three types: a) secondary origin-primary origin pore space; b) primary origin-secondary origin pore space, and c) micropore space. Porosity is 3.3-17.4%, and permeability is (0.1-667.97) × 10 -3 ?m 2.

LÜ, Xiuxiang; BAI, Zhongkai; ZHAO, Fengyun

62

Molecular structure effects on electron ranges and mobilities in liquid hydrocarbons: chain branching and olefin conjugation: mobility model  

International Nuclear Information System (INIS)

The behaviour of electrons in liquid hydrocarbons was studied; the electrons were generated by pulsed irradiation with x-rays. For a series of alkanes, alkenes and alkynes, the effect of molecular structure on secondary-electron penetration ranges and thermal-electron mobilities was studied. Although sphericity is important in determining the penetration range, flexibility is also important. Thus, the density-normalized range in the approximately spherical tetraethylmethane is closer to that of non-spherical diethylmethane than to that of tetramethylmethane. Electron mobilities are interpreted in terms of a model that contains a Gaussian distribution of solvated-electron-state energies, a conduction band, and thermally activated transitions between them. The model is a combination of the authors' treatment of electrons in ethers and Schiller's treatment of electrons in hydrocarbons. The percolation model does not provide a sufficiently complete interpretation of electron migration in hydrocarbons. (N.D.H.)

63

International Migration of Couples  

OpenAIRE

We present a theory on migration of dual-earner couples and test it in the context of international migration. Our model predicts that the probability that a couple emigrates increases in the home-country earnings of the primary earner. The effect of the home-country earnings of the secondary earner may go either way. We test our theory using population-wide Danish administrative data from 1982 to 2010. We analyze migration decisions separately for couples in which men earned more and couples...

Munk, Martin D.; Junge, Martin; Poutvaara, Panu

2013-01-01

64

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2003-07-01

65

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

66

Iatrogenic migration of VenaTech LP IVC filter to superior vena cava secondary to guidewire entrapment: case report and review of literature.  

Science.gov (United States)

Modern inferior vena cava (IVC) filters are generally safe devices for preventing pulmonary embolus, with fewer complications compared to earlier techniques of caval interruption. Despite continuing improvement in filter designs and insertion methods, complications still occur. The IVC filter complications resulting from iatrogenic causes are rare and include but are not limited to misplacement, filter tilting, incomplete deployment, and filter migration. We recently experienced a problem in which the Vena Tech LP filter (B. Braun, Bethlehem, Pennsylvania) migrated to the superior vena cava (SVC) immediately after successful deployment of the filter in the infrarenal venacava. The root cause analysis of this case revealed that the complication was related to blind pullout of the J-tipped guidewire following deployment of the filter in the IVC. This report highlights the potential risks of using a wire while an IVC filter is in place. PMID:23203598

Almestady, Rajaa; Spain, James; Bayona-Molano, Maria Del Pilar; Wang, Weiping

2013-01-01

67

Ab initio study of hydrogen migration in 1-alkylperoxy radicals.  

Science.gov (United States)

Alkylperoxy and hydroperoxyalkyl radicals are key reactive intermediates in hydrocarbon oxidation mechanisms. An understanding of the interconversion of these two species via a hydrogen migration reaction is of fundamental importance to the prediction of chain branching reactions and end product composition. An extensive ab initio investigation of the hydrogen migration reaction in 1-ethyl, 1-propyl, 1-butyl, 1-pentyl, and 1-hexylperoxy radicals is conducted to assess the validity of using cycloalkanes to model the ring strain of their transition states as well as the effect of both location of the migrating hydrogen and directionality of the remaining alkyl chain in the transition state of the reaction involving a secondary hydrogen. The G2 and CBS-Q composite methods are used to determine the activation energy and enthalpy of reaction relative to the alkylperoxy radical. Both methods show good agreement with five experimentally determined reaction enthalpies, having root mean squared deviations of 0.7 and 1.3 kcal mol(-1) for the CBS-Q and G2 methods, respectively. The effect of hydrogen abstraction site and transition state geometry, particularly axial and equatorial geometries of the remaining alkyl chain, on the activation energy, Arrhenius A-factor, tunneling, and rate coefficient are discussed. Differences between terminal adjacent and nonterminal adjacent secondary sites result in small but consistent differences in barrier height. Failure of key assumptions within the cycloalkane based estimation method leads to the break down in the accuracy for both small and large transition states. For large transition states, the breakdown of these assumptions also results in the failure of the current cycloalkane method as a conceptual model. Of great interest is the observed alteration in the preferred H-migration from the 1,5 to the 1,6 H-migration within the temperature region where these reactions are particularly important to the combustion mechanism. PMID:20883006

Davis, Alexander C; Francisco, Joseph S

2010-11-01

68

Planet Migration  

OpenAIRE

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...

Thommes, Edward W.; Lissauer, Jack J.

2010-01-01

69

Anuria súbita en paciente monorreno secundaria a migración de endoprótesis aórtica / Sudden anuria secondary to migration of aortic stent in a single kidney patient  

Scientific Electronic Library Online (English)

Full Text Available El manejo percutáneo de los aneurismas de aorta infrarrenal es una técnica menos agresiva, pero no está exenta de riesgos. La migración craneal de las endoprótesis es un proceso infrecuente en dicha técnica. Ante una revascularización renal izquierda de urgencia en que no se pueda tener acceso a una [...] vía anterior o la posibilidad de un autotrasplante, una buena alternativa es la realización de un shunt esplenorrenal mediante un acceso lumbar. Abstract in english Percutaneous acces to manage infrarenal aortic aneurysm is a less aggressive technique, but it’s not entirely risk free. The migration of stents isn’t a frequent complication in that percutaneous technique. Urgent left renal revascularition, when anterior approach or autologous transplantation is no [...] t possible, is feasibily by a splenorenal shunt through a lumbar approach.

S., Capdevila Querol; R., Gutiérrez Del Pozo; A., Franco de Castro; A., Aguilar; D., Truhán Cacho; J.B., Alcover García.

2005-05-01

70

Application possibilities of migration regularities of natural radioactive elements and their isotopes in the complex mineral resource exploration with special regard to hydrocarbon fluid prognose and reservoir study Pt. 1 and 2  

International Nuclear Information System (INIS)

Based primarily upon Soviet literature data, the author gives a survey, for the first time in Hungarian literature, of the most important results of radiometrical and radiohydrogeochemical research activity of more than 50 years. The extension of domestic hydrogeological and hydrogeochemical examinations to be performed for hydrocarbon exploration is suggested by determining the natural radioactive elements and their isotopes. Special emphasis is laid on the processing of water samples analyzed for some other purposes for U and Ra according to hydrocarbon geological (and uranium geological) aspects. These samples were taken in the mid-sixties from Hungary's hydrocarbon exploration wells. (A.L.)

71

Bird Migration  

Science.gov (United States)

The songs of spring are in the air, as northbound birds grace the skies. The following websites cover various aspects of the amazing and ancient phenomenon of bird migration. Hosted by the U.S. Geological Survey Northern Prairie Wildlife Research Center, the (1) first site is an online publication from the U.S. Fish and Wildlife Service on the Migration of Birds. This publication provides an extensive account of migration including sections on Techniques for Studying Migration, Evolution of Migration, Flight Speed and Rate of Migration, and many more. The (2) second site from birdnature.com is a webpage describing the Flyway Systems of North America accompanied by clearly labeled maps. The (3) third site from the University of Lund, Sweden introduces various research studies in the field of Migration Ecology including research information on Orientation and Navigation, Migration patterns, the Lund Wind Tunnel, and more. The (4) fourth site presents the Canadian Migration Monitoring Network, a standardized effort involving multiple stations in southern Canada and the northern United States to gather baseline data on northern breeding birds. Site visitors can link to information about species population trends, latest sightings, and to sites for any of the 22 stations. Journey North hosts the (5) fifth site, which tracks migrating bald eagles through the spring of 2004, providing migration updates, information about tracking bald eagle migration, and related educational lessons and activities. A National Geographic 2004 feature, Crane Cam is the (6) sixth site providing multimedia shows, a photo gallery, map, and viewings from a live remote camera at Audubon's Rowe Sanctuary. The (7) seventh site features an interactive Migration Game created by the Migratory Bird Center at the Smithsonian National Zoological Park. The (8) final site, from the Whyfiles contains brief sections on various aspects of bird migration such as navigation, flight strategies, raptor migration, and declining numbers of migrating songbirds. This site also links to information about monarch migration.

72

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

73

Transport of petroleum hydrocarbons in permafrost soils  

International Nuclear Information System (INIS)

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

74

Aromatic hydrocarbons  

International Nuclear Information System (INIS)

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

75

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

Directory of Open Access Journals (Sweden)

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

Salih Muhammad Awadh

2010-11-01

76

International Migration  

Science.gov (United States)

This Website, Push and Pull Factors of International Migration, features background and preliminary research data from a joint project of Eurostat and The Netherlands Interdisciplinary Demographic Institute the goal of which is to "improve understanding of the direct and indirect causes and mechanisms of international migration to the European Union from an internationally comparative perspective. The project is an effort to respond to the fact that "international migration flows have increased in magnitude and complexity over the past decades." Separate sections of the site provide information on the aim, objectives, and approach of the project; the research design; as well as a summary of first results on recent migration, migration motives, migration networks, and migration intentions; and further bibliographic and Web-based resources. The project is under the auspices of the Commission of the European Communities.

77

Pyrolysis of hydrocarbons from lignite semicoking tar  

Energy Technology Data Exchange (ETDEWEB)

Pyrolysis of hydrocarbons from lignite semicoking tar in the range 750-900{degree}C at a contact time within 0.5-6.0 s was studied. The yields of pyrocarbons, pyrolysis gas, and liquid products and the group and component compositions of the liquid and gaseous products were determined. The optimal pyrolysis parameters from the viewpoint of obtaining the maximal yield of particular 'secondary' hydrocarbons were recommended.

Platonov, V.V.; Ryl' tsova, S.V.; Proskuryakov, V.A.; Rozental, D.A.; Polovetskaya, O.S.

2000-07-01

78

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2003-07-01

79

Ab initio study of chain branching reactions involving second generation products in hydrocarbon combustion mechanisms.  

Science.gov (United States)

sec-Alkyl radicals are key reactive intermediates in the hydrocarbon combustion and atmospheric decomposition mechanisms that are formed by the abstraction of hydrogen from an alkane, or as a second generation product of n-alkyl H-migrations, C-C bond scissions in branched alkyl radicals, or the bimolecular reaction between olefins and n-alkyl radicals. Since alkanes and branched alkanes, which the sec-alkyl radicals are derived from, make up roughly 40-50% of traditional fuels an understanding of their chemistry is essential to improving combustion systems. The present work investigates all H-migration reactions initiated from an sec-alkyl radical that involve the movement of a secondary hydrogen, for the 2-butyl through 4-octyl radicals, using the CBS-Q, G2, and G4 composite methods. The resulting thermodynamic and kinetic parameters are compared to similar reactions in n-alkyl radicals in order to determine underlying trends. Particular attention is paid to the effect of cis/trans and 1,3-diaxial interactions on activation energies and rate coefficients. When combined with our previous work on n-alkyl radical H-migrations, a complete picture of H-migrations in unbranched alkyl radicals is obtained. This full data set suggests that the directionality of the remaining branched chains has a minimal effect on the rate coefficients for all but the largest viable transition states, which is in stark contrast to the differences predicted by the structurally similar dimethylcycloalkanes. In fact the initial location of the secondary radical site has a greater effect on the rate than does the directionality of the remaining alkyl chains. The activation energies for secondary to secondary reactions are much closer to those of the secondary to primary H-migrations. However, the rate coefficients are found to be closer to the corresponding primary to primary reaction values. A significant ramification of these results is that there will be multiple viable reaction pathways for these reactions instead of only one dominant pathway as previously believed. PMID:22048707

Davis, Alexander C; Francisco, Joseph S

2012-01-28

80

Migration Ecology  

Science.gov (United States)

This site from the University of Lund, Sweden, introduces various research studies in the field of Migration Ecology including research information on "Orientation and navigation," "Flight," "Migration patterns," and "Energetics." The mission of the group is "to forward, by research and teaching, the understanding of adaptive values and evolutionary possibilities and limitations in animal migration, -flight, -orientation and energetics." Many of the group's publications are available for free as PDFs, and the site offers a simple search mechanism to help visitors find the publications they are seeking.

Alerstam, Thomas

81

Operation Migration  

Science.gov (United States)

Operation Migration, a nonprofit conservation organization dedicated to teaching safe migratory routes to endangered and threatened birds, was co-founded by William Lishman -- the pilot who pioneered the use of ultralight aircraft to lead birds in flight. Operation Migration is part of a consortium created to safeguard the endangered Whooping crane against extinction. Visitors to this Web site can track the progress of seven ultralight-led Whooping cranes now making their way from Wisconsin to Florida for the winter. The Web site provides daily field reports of the migration, a map charting the progress of the flock, loads of photos, crane biographies, video clips, and more. The site also relates the engaging story of how Operation Migration got started, one that should sound familiar to those who've seen the feature film Fly Away Home.

82

Spring Migration  

Science.gov (United States)

The Spring Migration site from eNature.com and the National Wildlife Federation provides an online reference for bird enthusiasts that shows the dates that each species can be expected to return to its summer habitat. Site visitors can choose from a large number of species found in their range. Maps show summer and winter habitat ranges and migration patterns. The site also provides photos, field guide information, and bird call audio for each species.

83

Migration chemistry  

International Nuclear Information System (INIS)

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

84

Exact solutions in a model of vertical gas migration  

Energy Technology Data Exchange (ETDEWEB)

This work is motivated by the growing interest in injectingcarbon dioxide into deep geological formations as a means of avoidingatmospheric emissions of carbon dioxide and consequent global warming.One of the key questions regarding the feasibility of this technology isthe potential rate of leakage out of the primary storage formation. Weseek exact solutions in a model of gas flow driven by a combination ofbuoyancy, viscous and capillary forces. Different combinations of theseforces and characteristic length scales of the processes lead todifferent time scaling and different types of solutions. In the case of athin, tight seal, where the impact of gravity is negligible relative tocapillary and viscous forces, a Ryzhik-type solution implies square-rootof time scaling of plume propagation velocity. In the general case, a gasplume has two stable zones, which can be described by travelling-wavesolutions. The theoretical maximum of the velocity of plume migrationprovides a conservative estimate for the time of vertical migration.Although the top of the plume has low gas saturation, it propagates witha velocity close to the theoretical maximum. The bottom of the plumeflows significantly more slowly at a higher gas saturation. Due to localheterogeneities, the plume can break into parts. Individual plumes alsocan coalesce and from larger plumes. The analytical results are appliedto studying carbon dioxide flow caused by leaks from deep geologicalformations used for CO2 storage. The results are also applicable formodeling flow of natural gas leaking from seasonal gas storage, or formodeling of secondary hydrocarbon migration.

Silin, Dmitriy B.; Patzek, Tad W.; Benson, Sally M.

2006-06-27

85

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

Science.gov (United States)

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

Kandel, William; Massey, Douglas S.

2002-01-01

86

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

87

Monarch Migration.  

Science.gov (United States)

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

Williamson, Brad; Taylor, Orley

1996-01-01

88

Hydrocarbon Problems & Nature Principles  

OpenAIRE

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

Cramez, Carlos; Laherre?re, J.

2006-01-01

89

Neuronal Migration Disorders  

Science.gov (United States)

NINDS Neuronal Migration Disorders Information Page Table of Contents (click to jump to sections) What is Neuronal Migration Disorders? Is there ... being done? Clinical Trials Organizations What is Neuronal Migration Disorders? Neuronal migration disorders (NMDs) are a group ...

90

Hydrocarbon Plume Dynamics in the World? Most Spectacular Hydrocarbon Seeps, Santa Barbara Channel, California  

Science.gov (United States)

Large quantities of natural gas are emitted from the seafloor into the coastal ocean near Coal Oil Point, Santa Barbara Channel (SBC), California. Methane, ethane, and propane were quantified in the surface water at 79 stations in a 270 km2 area in order to map the surficial hydrocarbon plume and to quantify air-sea exchange of these gases. A time series was initiated for 14 stations to identify the variability of the mapped plume, and biologically-mediated oxidation rates of methane were measured to quantify the loss of methane in surface water. The hydrocarbon plume was found to comprise ~70 km2 and extended beyond study area. The plume width narrowed from 3 km near the source to 0.7 km further from the source, and then expanded to 6.7 km at the edge of the study area. This pattern matches the cyclonic gyre which is the normal current flow in this part of the Santa Barbara Channel - pushing water to the shore near the seep field and then broadening the plume while the water turns offshore further from the source. Concentrations of gaseous hydrocarbons decrease as the plume migrates. Time series sampling shows similar plume width and hydrocarbon concentrations when normal current conditions prevail. In contrast, smaller plume width and low hydrocarbon concentrations were observed when an additional anticyclonic eddy reversed the normal current flow, and a much broader plume with higher hydrocarbon concentrations was observed during a time of diminished speed within the current gyre. These results demonstrate that surface currents control hydrocarbon plume dynamics in the SBC, though hydrocarbon flux to the atmosphere is likely less dependent on currents. Estimates of air- sea hydrocarbon flux and biological oxidation rates will also be presented.

Mau, S.; Reed, J.; Clark, J.; Valentine, D.

2006-12-01

91

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

OpenAIRE

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

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

2006-01-01

92

Secondary parkinsonism  

Science.gov (United States)

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

93

Hydrocarbon Formation in Immature Sediments  

Directory of Open Access Journals (Sweden)

Full Text Available

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

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

D.D.J. ANTIA

2011-07-01

94

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

Science.gov (United States)

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

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

1995-04-01

95

Miracle of Winged Migration  

Science.gov (United States)

This site, from the Why Files contains brief sections on various aspects of bird migration such as navigation, flight strategies, raptor migration, and declining numbers of migrating songbirds. This site also links to information about monarch migration and the effects of global warming on migration of birds and butterflies alike.

Tenenbaum, David

96

Migration of Birds  

Science.gov (United States)

Hosted by the U.S. Geological Survey Northern Prairie Wildlife Research Center, this site is an online publication from the U.S. Fish and Wildlife Service on the Migration of Birds. This publication provides an extensive account of migration including sections on Techniques for Studying Migration, Evolution of Migration, Flight Speed and Rate of Migration, and many more.

Lincoln, Frederick C.

97

Imaging fluid/solid interactions in hydrocarbon reservoir rocks.  

Science.gov (United States)

The environmental scanning electron microscope (ESEM) has been used to image liquid hydrocarbons in sandstones and oil shales. Additionally, the fluid sensitivity of selected clay minerals in hydrocarbon reservoirs was assessed via three case studies: HCl acid sensitivity of authigenic chlorite in sandstone reservoirs, freshwater sensitivity of authigenic illite/smectite in sandstone reservoirs, and bleach sensitivity of a volcanic reservoir containing abundant secondary chlorite/corrensite. The results showed the suitability of using ESEM for imaging liquid hydrocarbon films in hydrocarbon reservoirs and the importance of simulating in situ fluid-rock interactions for hydrocarbon production programmes. In each case, results of the ESEM studies greatly enhanced prediction of reservoir/borehole reactions and, in some cases, contradicted conventional wisdom regarding the outcome of potential engineering solutions. PMID:8400441

Uwins, P J; Baker, J C; Mackinnon, I D

1993-08-01

98

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

99

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)

100

Model migration schedules incorporating student migration peaks  

OpenAIRE

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 t...

Tom Wilson

2010-01-01

101

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; anto produce dehydrogenated hydrocarbons; and, (g) withdrawing and recovering the dehydrogenated hydrocarbons, the improvement which comprises utilizing as the support a cerium-containing alumina

102

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.

103

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

104

Minneapolis Multi-Ethnic Curriculum Project--Migration Unit.  

Science.gov (United States)

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

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

105

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

106

International Migration and Remittances  

OpenAIRE

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

Dattatray Sitaram Bagade

2012-01-01

107

Migration and trade  

OpenAIRE

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

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

2011-01-01

108

Analyzing seismic imagery in the time-amplitude and time-frequency domains to determine fluid nature and migration pathways: A case study from the Queen Charlotte Basin, offshore British Columbia  

Science.gov (United States)

Combining time-amplitude and time-frequency information from seismic reflection data sets of different resolutions allows the analysis of anomalous reflections from very-shallow to great subsurface depths. Thus, it can enhance the imaging of subsurface features which have a frequency-dependent reflectivity such as gas. Analysing seismic data of different resolution in the time-amplitude and time-frequency domains is a powerful method to determine hydrocarbon migration pathways from deep reservoirs to the seafloor. This interpretation method has been applied to the formerly-glaciated offshore Queen Charlotte Basin hosting several seafloor pockmarks and mounds associated with the leakage of underlying hydrocarbon reservoirs. Low-frequency shadows observed in the time-frequency domain provide evidence of different resolutions that several anomalous reflection amplitudes may be attributed to the occurrence of gas. The seismic imagery shows that gas uses a fault to migrate from deep reservoirs included in Upper Mesozoic strata towards secondary reservoirs located along the fault plane into Neogene layers. Once gas reaches a porous cut-and-fill succession, migration changes from structurally- to stratigraphically-controlled before gas leaks through unconsolidated Quaternary sediments forming the shallow subsurface to eventually seep at the seafloor where pockmarks and carbonate mounds are formed.

Duchesne, Mathieu J.; Halliday, E. Julie; Barrie, J. Vaughn

2011-02-01

109

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.)

110

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

111

Coupling of faulting and hydrocarbon accumulation in Baiyun sag based by basin modelling  

Science.gov (United States)

Enormous hydrocarbon potential has been evaluated in the Baiyun sag in the continental shelf of the northern South China Sea. Faults are widespread around the sag and have profound effects on hydrocarbon migration and accumulation. Fault activities control the sedimentation of source rocks in the early stage, regulate the range of reservoirs in the middle stage, and dominate the seals and traps in the late stage. This paper makes attempt to present the controls of faults on hydrocarbon migration and accumulation with methods of faulting analysis and shale gauge ratio (SGR). Results show that faulting episodes couple well with the generations of hydrocarbon. Overpressure due to hydrocarbon generation may result in the acceleration of faulting activities at 18.5Ma. Active faults act as the perfect conduits of hydrocarbon vertical migration. Shale smear is much more credible in reflecting the sealing ability of motionless faults than the sheer faulting activity analysis. In the study region, most of the traps are positive structures consisting of anticlines and faulting anticlines. Hydrocarbon accumulation in the south faulting areas tends to be more favorable than in the north. The major expulsion stages are 23.8-16.5Ma and13.8-10.5Ma.

Sun, Longtao; Xie, Zhiyuan; Li, Yuanping; Sun, Zhen; Yang, Jianmin

2014-05-01

112

Migration Modes in Cancer Cell Motility  

Science.gov (United States)

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

Wu, Di; Aranda-Espinoza, Helim

2013-03-01

113

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

114

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

Science.gov (United States)

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

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

2009-04-01

115

Theoretical base of new technology of hydrocarbons exploration in the south Caspian basin  

International Nuclear Information System (INIS)

Full text : This article provides with new data, which are of great importance for the understanding of hydrocarbon system peculiarities if the south Caspian basin. There was determined non-coincidence and sometimes back correlation in the folded structure of complexes of different ages and also different orientation of axes of the folds and directions of faults in different tectonic zones. In the sedimentary cover of the south Caspian basin there were identified specific structures associated with generation and migration of hydrocarbons. Large-scale migration of hydrocarbons occurs instantly from time to time. It was determined that most earthquakes occurs in the south Caspian basin in the sedimentary cover at depth from 10 to 20 km and paragenesis of mud volcanos eruptions was determined too. There exist an opinion that the improved technology of hydrocarbon exploration will increase the efficiency of exploration works in a complex basin like the south Caspian one.

116

Formation of hydrocarbon deposits in a three-layer natural reservoir  

Energy Technology Data Exchange (ETDEWEB)

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

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

1982-01-01

117

Migration and Adult Education  

Science.gov (United States)

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

Gois, William

2007-01-01

118

On Marriage and Migration  

OpenAIRE

Marriage, migration and related phenomena such as marital stability, fertility and investment in human capital may be better explained by studying marriage and migration jointly. We thus proceed in this paper to explore the role of migration in obtaining joint labour-market and marriage-market equilibrium. This facilitates identification of several novel and testable hypotheses.

Stark, Oded

1988-01-01

119

Organic geochemistry of the Vindhyan sediments: Implications for hydrocarbons  

Science.gov (United States)

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

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

2014-09-01

120

Olefinic hydrocarbon isomerization process  

International Nuclear Information System (INIS)

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

121

HYDROCARBON POLLUTANTS FROM STATIONARY SOURCES  

Science.gov (United States)

The report gives results of a study of hydrocarbon pollutants from stationary sources. Early in the study, readily available information was assembled on stationary sources of hydrocarbon emissions and effluents. Information was also obtained on process descriptions, operating pa...

122

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)

123

Hydrocarbon resources in Quebec  

International Nuclear Information System (INIS)

A leading expert in exploration geology was asked his opinion regarding government intervention in hydrocarbon exploration and development with respect to sustainable development requirements. Fifty-one per cent of Quebec's energy consumption is attributed to hydrocarbons and 38 per cent to electricity. It is expected that proportions of this demand will remain the same for several decades. This paper evaluates Quebec's hydrocarbon potential and exploration to meet future energy demands. It was suggested that the Quebec government should explore the idea of uniting government, university and private enterprises in assessing the resource potential of Quebec's sedimentary basins with the possibility of using strategic information from oil and gas companies to improve existing databases. Quebec's objective is to improve energy security and supply and to improve the economic prosperity of Quebec's natural resource development, particularly hydrocarbons. It was also emphasized that oil and gas exploration should eventually be harmonized with renewable energy source development, a transition that could take several decades. 2 tabs., 2 figs

124

EFFECT OF HYDROCARBON COMPOSITION ON OXIDANT-HYDROCARBON RELATIONSHIPS. PHASE II. BLEND OF TOTAL HYDROCARBON EMISSIONS  

Science.gov (United States)

To assess the formation of atmospheric oxidants resulting from exhaust emitted by catalyst-equipped vehicles, chamber irradiations were conducted using a hydrocarbon blend representing total hydrocarbon emissions (exhaust, refueling and evaporation). Results were compared with pr...

125

Hydrocarbon Distribution in Sediments from the Southeast Coastal Region of Bangladesh  

Directory of Open Access Journals (Sweden)

Full Text Available The research deals with the study of the nature of hydrocarbons occurring at the coastal region of Bangladesh to assess the extent of hydrocarbon pollution in the marine environment. Accordingly, five sediment samples were analyzed for extraction of soluble organic matter, fractionation of extract into aliphatic hydrocarbons, aromatic hydrocarbons and polar compounds, molecular composition analysis of aromatic and aliphatic hydrocarbons? fractions and integration of results for the study of the nature and origin of hydrocarbons in the marine environment. Hydrocarbons present in the sediment samples might have originated from three main sources: a biosynthesis of aquatic organisms and/or diagenesis of alteration of bacteria, zooplankton, phytoplankton and higher plant derived organic matters; b migration of immature oil seep from deeper sources and c direct incorporation of fossil hydrocarbons discharged into the sea water by various sea-going vessels. The total hydrocarbons in five sediment samples from the study area ranged from 71.73 to 359.21ppm. Recommendations are made to take appropriate measure for the protection of the marine environment from further pollution.

Biplob Das

2002-01-01

126

Hydrocarbonization research: completion report  

Energy Technology Data Exchange (ETDEWEB)

Hydrocarbonization is a relatively simple process used for producing oil, substitute natural gas, and char by heating coal under a hydrogen-rich atmosphere. This report describes studies that were performed in a bench-scale hydrocarbonization system at Oak Ridge National Laboratory (ORNL) during the period 1975 to 1978. The results of mock-up studies, coal metering valve and flowmeter development, and supporting work in an atmospheric hydrocarbonization system are also described. Oil, gas, and char yields were determined by hydrocarbonization of coal in a 0.1-m-diam fluidized-bed reactor operated at a pressure of 2170 kPa and at temperatures ranging from 694 to 854 K. The nominal coal feed rate was 4.5 kg/h. Wyodak subbituminous coal was used for most of the experiments. A maximum oil yield of approx. 21% based on moisture- and ash-free (maf) coal was achieved in the temperature range of 810 to 840 K. Recirculating fluidized-bed, uniformly fluidized-bed, and rapid hydropyrolysis reactors were used. A series of operability tests was made with Illinois No. 6 coal to determine whether caking coal could be processed in the recirculating fluidized-bed reactor. These tests were generally unsuccessful because of agglomeration and caking problems; however, these problems were eliminated by the use of chemically pretreated coal. Hydrocarbonization experiments were carried out with Illinois No. 6 coal that had been pretreated with CaO-NaOH, Na/sub 2/CO/sub 3/, and CaO-Na/sub 2/CO/sub 3/. Oil yields of 14, 24, and 21%, respectively, were obtained from the runs with treated coal. Gas and char yield data and the composition of the oil, gas, and char products are presented.

Youngblood, E.L.; Cochran, H.D. Jr.; Westmoreland, P.R.; Brown, C.H. Jr.; Oswald, G.E.; Barker, R.E.

1981-01-01

127

Oil migration pattern in the Sirte Basin  

Energy Technology Data Exchange (ETDEWEB)

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

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

1995-08-01

128

A dengue model incorporating saturation incidence and human migration  

Science.gov (United States)

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

Gakkhar, S.; Mishra, A.

2015-03-01

129

Migration Policy Institute  

Science.gov (United States)

Founded in 2001, the Migration Policy Institute (MPI) evolved from a program at the Carnegie Foundation for International Peace. Since its inception, the MPI has been dedicated to examining the trends and processes associated with the movement of various people worldwide. The homepage offers a wide array of resources for the general public, journalists, and academicians. Looking at the â??In Focusâ? area on the homepage, visitors can download new working papers and reports with titles such as â??The New â??Boatâ?? Peopleâ? and â??Immigration Enforcement at the Worksite, Making it Workâ?. From the homepage, users can also make their way to the Migration Information Source website which contains global migration data, country migration profiles, and a glossary of migration terms. Visitors with specific questions can also view a list of experts in a variety of topics related to migration and email them directly.

130

Enzymatic transformation of hydrocarbons by methanotrophic organisms  

Energy Technology Data Exchange (ETDEWEB)

Soluble methane monooxygenase from a facultative methane-utilizing organism, Methylobacterium sp. CRL-26 or R6, catalyzed the NAD(P)H-dependent epoxidation/hydroxylation of a variety of hydrocarbons, including terminal alkenes, internal alkenes, substituted alkenes, branch-chain alkenes, alkanes (C1-C8), substituted alkanes, branch-chain alkanes, carbon monoxide, ether, cyclic and aromatic compounds. The NAD -linked dehydrogenases such as formate dehydrogenase or secondary alcohol dehydrogenase in the presence of formate or secondary alcohol, respectively, regenerated NAD/NADH required for the methane monooxygenase in a coupled enzymes reactions. Oxidation of secondary alcohols to the corresponding methylketones in methanotrophs is catalyzed by an NAD -dependent, zinc-containing, secondary alcohol hydrogenase. Primary alcohols were oxidized to the corresponding aldehydes by a phenazine methosulfate-dependent, pyrollo quinoline quinone (methoxatin or PQQ) containing, methanol dehydrogenase. Oxidation of aldehydes (C1 to C10) to the corresponding carboxylic acids is catalyzed by a heme-containing aldehyde dehydrogenase. Methanotrophs have been considered potentially useful for single cell protein (SCP), amino acids, and biopolymer production at the expense of growth on cheap and readily available C1 compounds. 80 references, 1 figure, 6 tables.

Patel, R.N.; Hou, C.T.

1983-01-01

131

Migration and Environmental Hazards  

OpenAIRE

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

132

Migration in Burkina Faso  

OpenAIRE

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

Wouterse, F. S.

2007-01-01

133

Suicidal Ideation and Migration Aspirations among Youth in Central Mexico  

OpenAIRE

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

Steven Hoffman

2013-01-01

134

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

135

Hydrocarbon bioremediation -- An overview  

International Nuclear Information System (INIS)

Bioremediation is the process that transforms xenobiotics introduced into the environment to a less toxic or innocuous form, or mineralizes them to inorganic species. The processes can be carried out through either aerobic or anaerobic pathways by indigenous heterotrophs or by specially engineered organisms. For some xenobiotics, the process can also be carried out by cometabolic processes, which use another compound as the carbon and energy source. This technique can be applied either in situ or ex situ. An overview is presented of real-world applications of a variety of hydrocarbon bioremediation approaches, including biopiling, bioventing, bioslurping, landfarming, electrobioreclamation, and biovertical circulation wells. Problems in translating laboratory and field-scale pilot test data to full-scale operating systems are discussed. Such issues include biodegradation enhancement, nutrient and electron acceptor delivery, alternative electron acceptors, and integration of biological, chemical, and physical approaches to hydrocarbon remediation

136

Direct hydrocarbon fuel cells  

Science.gov (United States)

The direct electrochemical oxidation of hydrocarbons in solid oxide fuel cells, to generate greater power densities at lower temperatures without carbon deposition. The performance obtained is comparable to that of fuel cells used for hydrogen, and is achieved by using novel anode composites at low operating temperatures. Such solid oxide fuel cells, regardless of fuel source or operation, can be configured advantageously using the structural geometries of this invention.

Barnett, Scott A.; Lai, Tammy; Liu, Jiang

2010-05-04

137

ADVANCES IN HYDROCARBON TECHNOLOGIES  

OpenAIRE

This paper provides an overview about today’s and future trends in using hydrocarbon technologies and related hydrogen technologies. The content of this presentation is devoted to hydrogen/bio-hydrogen production – with focus on-board fuel reforming and vehicular hydrogen storage. Hydrogen storage is widely recognized as a major technological barrier to the successful implementation of fuel cells for transportation and portable applications. The paper shows that GTL technology is undergoi...

Martin Bajus

2007-01-01

138

FROZEN HYDROCARBONS IN COMETS  

International Nuclear Information System (INIS)

Recent investigations of the luminescence of frozen hydrocarbon particles of icy cometary halos have been carried out. The process of luminescence of organic icy particles in a short-wavelength solar radiation field is considered. A comparative analysis of observed and laboratory data leads to 72 luminescent emission lines in the spectrum of the comet 153P/Ikeya-Zhang. The concept of cometary relict matter is presented, and the creation of a database of unidentified cometary emission lines is proposed.

139

[Migration to metropolitan Mexico City].  

Science.gov (United States)

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

Cantu Gutierrez, J J; Luque Gonzalez, R

1990-01-01

140

Migration Information Source  

Science.gov (United States)

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

141

Monarchs and Migration  

Science.gov (United States)

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

0000-00-00

142

Migration of Egyptians.  

Science.gov (United States)

This study is concerned with recent trends in emigration from Egypt, with particular emphasis on the migration of Egyptians to the Arab oil-exporting countries of the Middle East since 1973. The benefits and costs of this migration for Egypt are considered. PMID:12279539

Oweiss, I M

1980-07-01

143

Temporary Migration and Economic Assimilation  

OpenAIRE

In this paper, I study temporary migrations, and its consequences for immigrants' behaviour. I distinguish between temporary migrations where the return time is exogenous, and temporary migrations where the migrant chooses when to return. I then illustrate the consequences both types of temporary migration have for migrants' behaviour (as opposed to a permanent migration). If migrations are non-permanent, then this has also consequences for the way empirical models need to be specified. The p...

Dustmann, Christian

2000-01-01

144

ADVANCES IN HYDROCARBON TECHNOLOGIES  

Directory of Open Access Journals (Sweden)

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

Martin Bajus

2007-07-01

145

Forced Migration Projects  

Science.gov (United States)

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

146

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

Science.gov (United States)

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

Lupe, Robert; Ahlbrandt, Thomas S.

1975-01-01

147

Synthesis of PNA hydrocarbons  

Energy Technology Data Exchange (ETDEWEB)

The synthesis of PNA hydrocarbons usually includes ring construction, aromatization, removal of oxygen or other heteroatoms and in some cases specific placement of alkyl or aryl groups. These topics are of current interest in our laboratory. We have examined the regioselectivity of the Haworth sequence (Scheme I, Table I) and chromic acid oxidation at the benzylic position (Scheme II) as routes to 1-tetralones which in turn can become parent aromatic hydrocarbons or alkyl substituted ones (Scheme III). Simultaneous aromatization and deoxygenation can be accomplished in a single step by heating 1-tetralones in the presence of alkali (Scheme IV, Table VI). The deoxidative coupling of substituted acetophenones to stilbene types using active titanium species as coupling agents and subsequent photocyclization (Scheme IX) has provided a convenient route to polymethylphenathrenes. The maleic anhydride (Diels-Alder) route to ring construction (Scheme X) can be improved through use of Pd/C or PbO/sub 2/ as a reagent for bis-decarboxylation of vicinal anhydrides.

Eisenbraun, E.J.; Premasagar, V.; Holba, A.G.; Keen, G.W.

1980-08-01

148

Mechanics of vacuum-enhanced recovery of hydrocarbons  

International Nuclear Information System (INIS)

A growing body of field data demonstrates the enhancement of product recovery that can be achieved by applying a partial vacuum to recovery wells. Typical explanations for the observed improvement in performance invoke an increased slope of the cone of depression created in the water-table surface. Explanations related to water-table slope do not consider the gradient induced in the hydrocarbon by virtue of the airflow. Also, the airflow may induce a gradient in the aqueous phase that is not reflected in a water-table drawdown. The equations for steady-state flow of three immiscible fluids elucidate the fundamental mechanics of vacuum-enhanced recovery or bioslurping. Airflow to the recovery well causes hydrocarbon to migrate toward the well, independent of any gravity effects that may be created. Also, the relative permeability to hydrocarbon is affected by both water and airflow in the vicinity of the recovery well. Two critical airflow rates delineate the conditions for which only air is recovered, air and hydrocarbon are recovered, and all three phases are recovered

149

Volatile Hydrocarbon Pheromones from Beetles  

Science.gov (United States)

This chapter reviews literature about hydrocarbons from beetles that serve as long-range pheromones. The most thoroughly studied beetles that use volatile hydrocarbon pheromones belong to the family Nitidulidae in the genera Carpophilus and Colopterus. Published pheromone research deals with behav...

150

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.

151

Reconstructing Teacher Identities: Shock, Turbulence, Resistance and Adaptation in Caribbean Teacher Migration to England  

Science.gov (United States)

The findings reported and discussed in this article extend existing research in the fields of education, migration and identity which focuses on the impact of overseas trained teachers (OTTs) in London's secondary schools. In recent years, researchers have examined the issue of international teacher migration from the perspective of a "brain…

Washington-Miller, Paul

2009-01-01

152

UV Raman spectroscopy of hydrocarbons.  

Science.gov (United States)

In this paper, the UV Raman spectra of a large number of saturated and alkyl-substituted monocyclic, bicyclic and polycyclic aromatic hydrocarbons are obtained at 220 and 233 nm excitation wavelengths. Also included are nitrogen- and sulphur-containing hydrocarbons. The spectra obtained are fluorescence free, even for such highly fluorescent compounds as perylene, consistent with earlier reports of UV Raman spectra of hydrocarbons. The hydrocarbon UV Raman spectra exhibit greatly improved signal-to-noise ratio when in the neat liquid or solution state compared with the neat solid state, suggesting that some surface degradation occurs under the conditions used here. Assignments are given for most of the bands and clear marker bands for the different classes of hydrocarbons are readily observable, although their relative intensities vary greatly. These results are discussed in the context of structure and symmetry to develop a consistent, molecular-based model of vibrational group frequencies. PMID:15482987

Loppnow, G R; Shoute, L; Schmidt, K J; Savage, A; Hall, R H; Bulmer, J T

2004-11-15

153

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.

154

Signs of Migration  

Science.gov (United States)

Students research and examine the practical and instinctual characteristics of the migration patterns of many different animal species. The will also work in groups to illustrate their research and make presentations.

KQED

2007-08-30

155

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

Hüttel, Hans; Kleist, Josva

1999-01-01

156

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

157

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

158

Type II Migration is not Locked to Viscous Disk Evolution  

CERN Document Server

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

159

Permeable bio-reactive barriers for hydrocarbon remediation in Antarctica  

Energy Technology Data Exchange (ETDEWEB)

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

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

2010-07-01

160

Thermal decomposition of cadmium alkyl diperoxides in aromatic hydrocarbons  

International Nuclear Information System (INIS)

Thermal decomposition of cadmium diperoxides, using as an example dipropyl peroxicadmium (1) and dibutyl peroxicadmium (2), has been studied. The process is conducted in toluene and isopropyl benzene. The peroxides (1, 2) in aromatic hydrocarbons decompose with a measurable rate at the temperature above 313 K. Decomposition of cadmium alkyl diperoxides takes place in two macrostages according to coordinated mechanism both by means of intramolecular regrouping with ?-hydrogen atom migration and as a result of intermolecular interaction. Cadmium acylate is one of the main metal-containing products of thermal decomposition

161

Migration behaviour of iodine in nuclear fuel  

International Nuclear Information System (INIS)

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

162

Secondary electron emission from diamond surfaces  

International Nuclear Information System (INIS)

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

163

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

164

Secondary Current and Classification of River Channels  

Directory of Open Access Journals (Sweden)

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

Kaguchwa John Njenga

2013-01-01

165

Process of hydrocarbon gases production  

International Nuclear Information System (INIS)

The invention concerns to process of hydrocarbons gases production from oil sands. The purpose of the invention is increasing of desired product output. Process of hydrocarbon gases production includes heating of oil sands and simultaneous its irradiation by both an ultraviolet and a visible radiation with length wave is equal to 250-800 nm. The process is carried out at temperature of 260-595 deg C. The output of hydrocarbon gases grows with increase of irradiation time. For the splitting of oil sands it is possible apply ultraviolet lamps, lasers and synchrotron radiation in the specified interval of waves length. 3 refs

166

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

International Nuclear Information System (INIS)

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

167

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

International Nuclear Information System (INIS)

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

168

MICROBIAL DEGRADATION OF HALOGENATED HYDROCARBONS  

Science.gov (United States)

Biochemical and soil microbiology studies indicate that numerous mechanisms exists for the dehalogenation of both aliphatic and aromatic hydrocarbons. Tests described in this paper demonstrate that enzymatic systems are capable of dehalogenation. The report does not answer the qu...

169

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

170

Secondary seed dispersal and its role in landscape organization  

Science.gov (United States)

Mathematical models of banded vegetation patterns predict rapid upslope migration of vegetated patches not realized in field observations, a key point of disagreement between theory and observation. It is shown that the disagreement between model results and field observations can arise from seed dispersal dynamics. Two representations of biomass movement are used to test the hypothesis that secondary seed dispersal in overland flow inhibits band migration. The first is based on coupling down-slope water transport and seed advection. The second uses a kernel-based representation of seed transport where an anisotropic dispersal kernel combines the effects of isotropic primary and downslope secondary seed dispersal, and ensures that conclusions about secondary dispersal are independent of diffusive representations of biomass movement. The analysis demonstrates that secondary seed dispersal can retard upward movement of banded vegetation irrespective of the precise representation of biomass movement as long as the anisotropic effects are accounted for.

Thompson, Sally; Katul, Gabriel

2009-01-01

171

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

172

Predicting hydrocarbon release from soil  

International Nuclear Information System (INIS)

'Full text:' The remediation of hazardous chemicals from soils can be a lengthy and costly process. As a result, recent regulatory initiatives have focused on risk-based corrective action (RBCA) approaches. Such approaches attempt to identify the amount of chemical that can be left at a site with contaminated soil and still be protective of human health and the environment. For hydrocarbons in soils to pose risk to human heath and the environment, the hydrocarbons must be released from the soil and accessible to microorganisms, earthworms, or other higher level organisms. The sorption of hydrocarbons to soil can reduce the availability of the hydrocarbon to receptors. Typically in soils and sediments, there is an initial fast release of a hydrocarbon from the soil to the aqueous phase followed by a slower release of the remaining hydrocarbon to the aqueous phase. The rate and extent of slow release can influence aqueous hydrocarbon concentrations and the fate and transport of hydrocarbons in the subsurface. Once the fast fraction of the chemical has been removed from the soil, the remaining fraction of a chemical may desorb at a rate that natural mechanisms can attenuate the released hydrocarbon. Hence, active remediation may be needed only until the fast fraction has been removed. However, the fast fraction is a soil and chemical specific parameter. This presentation will present a tier I type protocol that has been developed to quickly estimate the fraction of hydro to quickly estimate the fraction of hydrocarbons that are readily released from the soil matrix to the aqueous phase. Previous research in our laboratory and elsewhere has used long-term desorption (four months) studies to determine the readily released fraction. This research shows that a single short-term (less than two weeks) batch extraction procedure provides a good estimate of the fast released fraction derived from long-term experiments. This procedure can be used as a tool to rapidly evaluate the release and bioavailability of hydrocarbons in a contaminated soil. This knowledge can enhance the selection and determine the duration of a proper remediation strategy. Information will be provided on the correlation of the results from this protocol to the results of chemical loss in contaminated soil bioremediation systems. This research has been completed, the data is currently being analyzed and the results will be fully evaluated by early 2002. As a result, the protocol and potential applications to field decisions will be presented and discussed. (author)

173

Bioassay of polycyclic aromatic hydrocarbons  

Energy Technology Data Exchange (ETDEWEB)

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

Van Kirk, E.A.

1980-08-01

174

The Great Migration  

Science.gov (United States)

The 'Great Migration' of African Americans out of the southern United States in the decades from 1900 to 1940 has few parallels in U.S. history. This unit incorporates the use of Geographic Information Systems (GIS) software to analyze demographic changes related to the migration, specifically who was involved, where they came from, and where they went. Students will also use primary sources including letters, pictures, songs, and poems to explore the reasons that over two million men, women, and children left the South during this period.

Rick Thomas

2007-01-01

175

Unix Application Migration Guide  

CERN Document Server

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

176

Migration, klima og sundhed  

DEFF Research Database (Denmark)

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

Tellier, Siri; Carballo, Manuel

2009-01-01

177

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

178

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

179

Evaluation of hydrocarbon potential  

Energy Technology Data Exchange (ETDEWEB)

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

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

1992-09-30

180

Evaluation of hydrocarbon potential  

International Nuclear Information System (INIS)

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

181

HYDROCARBONS RESERVES IN VENEZUELA  

Energy Technology Data Exchange (ETDEWEB)

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

Gonzalez Cruz, D.J.

2007-07-01

182

Quantifying Net OH Radical Consumption by Hydrocarbons and Their Oxidation Products in a Small Environmental Chamber  

Science.gov (United States)

The OH-initiated oxidation of hydrocarbons begins a complex chain of chemical reactions that lead to a variety of products such as greenhouse gases, other reactive species, and secondary organic aerosol. During these chemical processes, the hydrocarbon oxidation products will consume and produce additional OH radicals. Counting these OH radicals is, however, uncertain from reaction mechanisms alone. Therefore, a laboratory method is developed to count the net number of OH radicals consumed or produced by the oxidation of hydrocarbons and subsequent reaction products in the highly oxidizing environment of a Potential Aerosol Mass chamber. The amount of OH consumed is determined by first creating an OH exposure calibration curve relating OH exposure to OH consumed using carbon monoxide (CO). Carbon monoxide is an ideal calibration gas because only one OH radical is consumed per reaction, and its reaction products, carbon dioxide (CO2) and hydrogen (H), are unlikely to consume or produce additional OH radicals. Then, OH exposure is measured for a hydrocarbon over a range of atmospherically relevant mixing ratios. Finally, the net number of OH radicals consumed or produced by the hydrocarbon is estimated by comparing the hydrocarbon OH exposure curve with the calibration curve. This technique is applied to several hydrocarbons: ?-pinene, isoprene, m-xylene, and propane. These experiments reveal that m-xylene and its reaction products consume the most OH radicals, followed by isoprene, ?-pinene, and then propane. Experiments suggest that these hydrocarbons and subsequent reaction products consume between about 1.5 and 5 OH radicals per molecule, though theoretical OH counting from reaction mechanisms suggest a range of 2 to 3.5 OH radicals per molecule. This method can be applied to a suite of hydrocarbons to create a complete profile of hydrocarbon contributions to OH consumption in the atmosphere.

Samuelson, T. B.; Brune, W. H.; Lambe, A. T.; Davidovits, P.; Onasch, T. B.

2012-12-01

183

Seasonal Survival Probabilities Suggest Low Migration Mortality in Migrating Bats  

OpenAIRE

Migration is adaptive if survival benefits are larger than costs of residency. Many aspects of bat migration ecology such as migratory costs, stopover site use and fidelity are largely unknown. Since many migrating bats are endangered, such information is urgently needed to promote conservation. We selected the migrating Leisler's bat (Nyctalus leisleri) as model species and collected capture-recapture data in southern Switzerland year round during 6 years. We estimated seasonal survival and ...

Giavi, Simone; Moretti, Marco; Bontadina, Fabio; Zambelli, Nicola; Schaub, Michael

2014-01-01

184

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

185

Forced Migration Online  

Science.gov (United States)

Designed to function as a comprehensive website that provides access to various resources on forced human migration, this site is provided through the courtesy of the staff at the Refugee Studies Centre at the University of Oxford. While the users of this site will encounter a seamlessly integrated resource, the site contains four separate components. These elements include a searchable digital library, a searchable catalogue with descriptions of and links to Internet-based resources, and a series of geographic and thematic research guides. The homepage offers users access to all of these resources, along with a sidebar that features relevant upcoming events as the International Day of Older Persons. The site also affords visitors access to the full-text of three important publications in the field: Disasters, Forced Migration Review, and International Migration Review (some archived journals are several years behind the current issue). It is worth noting that the homepage also contains a link to a nice introductory essay by Sean Loughna titled "What is Forced Migration?"

186

Net Migration Statistics  

Science.gov (United States)

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

187

MEXICAN MIGRATION PROJECT  

Science.gov (United States)

The Mexican Migration Project is designed to make timely, high-quality data on documented and undocumented Mexican migrants available to researchers and policy analysts. Each year since 1987 the project has administered a semi-structured interview schedule to representative sampl...

188

Fall armyworm migration patterns.  

Science.gov (United States)

Fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), infestations in most of North America arise from annual migrations of populations that overwinter in southern Texas and Florida. Cytochrome Oxidase I haplotype profiles within the fall armyworm corn-strain, the subgroup tha...

189

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

190

Religion, migration og integration  

DEFF Research Database (Denmark)

Sammenhængen mellem religion og integration har de sidste år været genstand for debat. Artiklen kommer ind på begreber og sammenhænge relateret til området (migration, diaspora, assimilation, etnicitet, kultur) og ser på religionens mulige rolle som negativ eller positiv ressource i integrationsspørgsmål.

Borup, JØrn

2010-01-01

191

Practical Data Migration  

CERN Document Server

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

Morris, Johny

2012-01-01

192

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)

193

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 131133I, 60Co, 103106Ru, 122124125Sb, /sup 99m,99/Tc, and 99Mo. Also migrating are traces of 238239240Pu 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 tablesremedial action. 4 tables

194

The International Organization for Migration in Global Migration Governance  

OpenAIRE

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

Poulsen, Sofie Havn; Andersen, Lise

2011-01-01

195

21 CFR 178.3650 - Odorless light petroleum hydrocarbons.  

Science.gov (United States)

... true Odorless light petroleum hydrocarbons. 178.3650...CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT...3650 Odorless light petroleum hydrocarbons. Odorless light petroleum hydrocarbons may be...

2010-04-01

196

Two Centuries of International Migration  

OpenAIRE

This is a draft chapter for B. R. Chiswick and P. W. Miller (eds.) Handbook on the Economics of International Migration. It provides an overview of trends and developments in international migration since the industrial revolution. We focus principally on long-distance migration to rich destination countries, the settler economies in the nineteenth century and later the OECD. The chapter describes the structure, direction and determinants of migration flows and the assimilation experience of ...

Ferrie, Joseph; Hatton, Timothy J.

2013-01-01

197

The dynamics of mass migration  

OpenAIRE

We specify a set of equations defining a dynamic model of international migration and estimate its parameters by using data specially collected in Mexico. We then used it to project the a hypothetical Mexican community population forward in time. Beginning with a stable population of 10,000 people, we project ahead 50 years under three different assumptions: no international migration; constant probabilities of in- and out-migration, and dynamic schedules of out- and in-migration that change ...

Massey, Douglas S.; Zenteno, Rene M.

1999-01-01

198

European Integration and Labour Migration  

OpenAIRE

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

199

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

International Nuclear Information System (INIS)

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

200

An urban aquifer and the presence of petroleum hydrocarbons  

International Nuclear Information System (INIS)

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

201

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

202

Hydrocarbons as markers for identifying postirradiated peanuts  

International Nuclear Information System (INIS)

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

203

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1980-01-01

204

Migration and sensory changes of packaging materials caused by ionising radiation  

International Nuclear Information System (INIS)

Irradiation of packaging materials--in most cases plastics--generally lead to a formation of free radicals and ions, with secondary effects such as cross-linking as well as oxidative chain scission. These effects result in a formation of volatile radiolysis products which may induce off-odours in the polymers and may change the migration characteristics of packaging materials. Irradiation affect also polymer additives which change the specific migration behaviour of polymer additives and additive related decomposition products. Migration and sensory changes of pre-sterilised packaging materials have consequences on the quality of packaged goods and consumer's safety. Therefore, migration and sensory properties of packaging materials have specific regulations. Within this paper the effects of the formation of radiolysis products on overall migration, specific migration of food additives or radiolysis products as well as on sensory changes are discussed in view of current European food law

205

Migration scenarii in extrasolar systems  

OpenAIRE

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 directe...

Crida A.

2011-01-01

206

Migrations in Slovenian geography textbooks  

Directory of Open Access Journals (Sweden)

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

Jurij Senega?nik

2013-12-01

207

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

208

Diasporas, Migration & Identities  

Science.gov (United States)

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

209

Integration by migration?  

Science.gov (United States)

"In terms of trade and capital flows, the Middle East is one of the least economically integrated regions of the world. The major exception is labor mobility, where intraregional migration flows are extensive. The explanation for this pattern lies in the extreme differences in factor endowments across the region and development policies adopted by both labor-importing and exporting countries. Because the obstacles to trade in goods have been greater than the obstacles to migration, labor mobility and its associated capital flows have been the most important mechanism through which the benefits of the oil windfall have been spread to the poorer states of the region. There is evidence that incomes across the Middle East have become more equal." PMID:12346246

Shafik, N

1994-01-01

210

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

Schwarz, C.

2004-06-01

211

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

OpenAIRE

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

212

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

213

Education, unemployment and migration  

OpenAIRE

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

Eggert, Wolfgang; Krieger, Tim; Meier, Volker

2009-01-01

214

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.

215

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

216

Retrograde Gastrojejunostomy Tube Migration  

Science.gov (United States)

Percutaneous enteral feeding tubes are placed about 250,000 times each year in the United States. Although they are relatively safe, their placement may be complicated by perforation, infection, bleeding, vomiting, dislodgment, and obstruction. There have been numerous reports of antegrade migration of gastrojejunostomy (G-J) tubes. We report a case of G-J tube regurgitation following protracted vomiting and discuss the management of this very rare entity. PMID:25614839

Adesina, Adeleke; Rammohan, Guhan

2014-01-01

217

Migration, trade and unemployment  

OpenAIRE

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

Heid, Benedikt; Larch, Mario

2012-01-01

218

Governance in Nurse Migration  

OpenAIRE

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

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

2012-01-01

219

Hydrocarbon and by-product reserves in British Columbia 1995  

International Nuclear Information System (INIS)

Oil, gas, and gas by-product reserves in British Columbia were reviewed. A historical record of compiled data of British Columbia's reserves of crude oil and natural gas liquids from 1962 to 1995 were presented. A summary of the progress achieved during 1995 regarding horizontal oil and gas well technology, secondary and tertiary recovery, under-balanced drilling, and unconnected reserves was included. Detailed basic data on a field/pool/project basis was provided for crude oil reserves, raw gas reserves, pool gas analysis reports, and remaining hydrocarbon by-products

220

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.

221

Geochemical criteria of migration of natural gases in the Miocene sediments of the Bengal Foredeep, Bangladesh  

Science.gov (United States)

Thirteen trillion cubic feet of estimated recoverable gas along with 40 million barrels of condensates have been discovered in Miocene sandstones of the Bengal Foredeep, Bangladesh. The gases are mostly dry and sulphur free with a very low content of non-hydrocarbons. The terrestrial organic matter of Miocene shales at an early stage of maturation ( R0 = 0.4-0.6%) is the source of natural gases in the region. Based on the relative ratio of C 2/C 3+ three gas accumulation zones could be distinguished in the region: northern ( C2/ C3+ = 1.98), central ( C2/ C3+ = 3.62), and southern ( C2/ C3+ = 4.90), which coincide with the three major tectonic elements of the region. Such types of distribution of C 2/C 3+ values in the three accumulation zones are related to the different adjacent hydrocarbon generative depression as well as the processes of migration. The physico-chemical parameters like C 2+, 100·C 2+/C I and 100·C 3+/C I decrease from the platform flank to folded flank, and from Sylhet and Hatia Troughs to Modhupur High, indicating the migration direction and pathways. A trend of change in the isotopic composition of methane ( ?13 C I)is also observed in the same direction. The value ?13 C 1 becomes heavier during the process of lateral migration and lighter during the tertiary migration within the multipay zone gas fields. The lateral migration plays the major role for the occurrence of hydrocarbon accumulation in the region. Maximum concentration of hydrocarbons may be expected to occur in the folded flank and the Tangail-Tripura High.

Shamsuddin, A. H. M.; Khan, S. I.

222

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

223

Ambient aromatic hydrocarbon measurements at Welgegund, South Africa  

Science.gov (United States)

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

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

2014-07-01

224

THE PHOTOTOXICITY OF POLYCYCLIC AROMATIC HYDROCARBONS  

Science.gov (United States)

The U.S. Environmental Protection Agency (EPA) continues to be interested in developing methods for the detection of polycyclic aromatic hydrocarbons (PAHS) in the environment. Polycyclic aromatic hydrocarbons (PAHS) are common contaminants in our environment. Being major product...

225

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 ...

226

Total Petroleum Hydrocarbons (TPH): ToxFAQs  

Science.gov (United States)

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

227

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

228

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

Energy Technology Data Exchange (ETDEWEB)

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)

Kuznetsov, Yu.; Legin, E.; Legin, V. [Khlopin Radium Institute, St. Petersburg (Russian Federation); Shishlov, A.; Savitskii, Yu. [Krasnoyarsk Mining and Chemical Combine, Krasnoyarsk (Russian Federation); Novikov, A.; Goryachenkova, T. [Russian Academy of Sciences, Institute of Geochemistry and Analytical Chemistry, Moscow (Russian Federation)

2001-03-01

229

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)

230

Dissociative recombination of hydrocarbon ions  

International Nuclear Information System (INIS)

Rate constants and product distributions have been measured for a number of hydrocarbon ions at the CRYRING facility at the Stockholm University. Rate constants at 300 K are about 5x10-7 cm-3 s-1. The electron temperature dependences are also roughly constant and follow a power law. The products appear to correlate with reaction exothermicity

231

Dissociative recombination of hydrocarbon ions  

Energy Technology Data Exchange (ETDEWEB)

Rate constants and product distributions have been measured for a number of hydrocarbon ions at the CRYRING facility at the Stockholm University. Rate constants at 300 K are about 5x10{sup -7} cm{sup -3} s{sup -1}. The electron temperature dependences are also roughly constant and follow a power law. The products appear to correlate with reaction exothermicity.

Viggiano, A A [Air Force Research Laboratory, Space Vehicles Directorate, Hanscom AFB, MA 01731 (United States); Ehlerding, A [Department of Physics, AlbaNova, Stockholm University, SE-106 91, Stockholm (Sweden); Arnold, S T [Air Force Research Laboratory, Space Vehicles Directorate, Hanscom AFB, MA 01731 (United States); Larsson, M [Department of Physics, AlbaNova, Stockholm University, SE-106 91, Stockholm (Sweden)

2005-01-01

232

International Migration Diversification: A New Perspective to Migration Management  

OpenAIRE

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 ...

Bulley, Cynthia A.; Peter Quartey

2014-01-01

233

Optimizing Total Migration Time in Virtual Machine Live Migration  

OpenAIRE

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

Gustafsson, Erik

2013-01-01

234

Migration circulaire au Liban  

OpenAIRE

Le Liban est un pays d’émigration par excellence mais aussi un pays d’accueil des immigrés. La migration circulaire est une notion absente du paysage juridico-politique libanais. Pourtant, plusieurs dispositions du droit libanais attestent de ce phénomène pour certaines catégories d’immigrés d’une façon claire et nette. Par ailleurs, le cadre juridique et social permet l’existence d’immigrés circulaires au Liban. Enfin, il apparaît qu’à l’échelle des autorités liba...

Jouni, Hassan

2009-01-01

235

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!

Kyle Crowder

236

Climate and Human Migrations  

Science.gov (United States)

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

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

2002-10-25

237

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

Science.gov (United States)

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

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

2014-09-19

238

Cell migration in the forebrain.  

Science.gov (United States)

The forebrain comprises an intricate set of structures that are required for some of the most complex and evolved functions of the mammalian brain. As a reflection of its complexity, cell migration in the forebrain is extremely elaborated, with widespread dispersion of cells across multiple functionally distinct areas. Two general modes of migration are distinguished in the forebrain: radial migration, which establishes the general cytoarchitectonical framework of the different forebrain subdivisions; and tangential migration, which increases the cellular complexity of forebrain circuits by allowing the dispersion of multiple neuronal types. Here, we review the cellular and molecular mechanisms underlying each of these types of migrations and discuss how emerging concepts in neuronal migration are reshaping our understanding of forebrain development in normal and pathological situations. PMID:12626695

Marín, Oscar; Rubenstein, John L R

2003-01-01

239

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

240

Biodegradation of petroleum hydrocarbons in hypersaline environments  

Scientific Electronic Library Online (English)

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

Luiz Fernando, Martins; Raquel Silva, Peixoto.

2012-09-01

241

Migration of Molecules and Dust in the Universe. Limitations of Panspermia  

Science.gov (United States)

Types of astronomical objects that may contain molecules are listed. Possible forms of migration of molecules are briefly described. Also described are: properties of interstellar molecular clouds, structure of interstellar dust grains, observational manifestations of polycyclic aromatic hydrocarbons and fullerenes, evolution of cosmic dust grains, the dust component of interstellar wind, possible mechanisms of migration of molecules and dust on scale from planetary systems to galaxies, Hoyle and Wickramasinghe hypothesis about the biological nature of some dust grains and the limitations of the area of possible panspermia

Bochkarev, N. G.

2014-10-01

242

Education and the decision to migrate: an econometric analysis of migration in Venezuela.  

Science.gov (United States)

Interstate labor force migration in Venezuela was estimated for 3 groups of migrants classified by their own educational levels. Regional educational levels and education-specific average wages were included as explanatory variables in order to distinguish between the various effects of education on migration and to estimate differences in the response of educated and uneducated migrants to other explanatory variables. The basic model resembled that used in other econometric studies of migration; migration was assumed to be a function of a number of origin and destination state characteristics which were believed likely to represent costs and benefits of living in various states for most persons. Migration rates rather than absolute numbers were the dependent variable. Zellner's regression technique was employed, and appropriate F statistics were used to test the null hypothesis of equal response of migrants to each of the explanatory variables across educational levels. A substantial proportion of the variance in migration rates was explained for each level of education. The results showed that educated members of the labor force in Venezuela are more mobile and also that there are significant differences in the responses of educated and uneducated migrants to variables which reflect the costs and benefits of alternative locations. The educated were less deterred by increased distance and more responsive to wage rates in alternative locations. The educated appear to be more mobile because of their greater access to information and greater incentives to make additional investments in search of better opportunities. Both educated and uneducated migrants are attracted to more populated regions but the elasticity is almost twice as high for the educated. Educational opportunity was found to be an important locational advantage for those who already had attended secondary school. The less educated are less likely to move to states with high educational levels, perhaps because they fear job competition from the educated. Destination unemployment variables were not highly significant for the uneducated. Results of the study indicate that disaggregation of migration by educational levels is necessary for a clear understanding of the complex relationships involved. PMID:12339297

Levy, M B; Wadycki, W J

1974-03-01

243

International Migration and Human Development  

OpenAIRE

This paper reviews the relationship between international migration and human development. First, it reviews what we know about the factors that drive migration from developing to developed countries. Second, it reviews existing knowledge about the impact of international migration and remittances on the economic and human development of migrants’ source countries. These first two sections of the paper are accompanied by an assessment of the gaps in our knowledge that need to...

Yang, Dean

2009-01-01

244

Orbital Migration Models under Test  

OpenAIRE

Planet-disk interaction predicts a change in the orbital elements of an embedded planet. Through linear and fully hydrodynamical studies it has been found that migration is typically directed inwards. Hence, this migration process gives natural explanation for the presence of the 'hot' planets orbiting close to the parent star, and it plays a mayor role in explaining the formation of resonant planetary systems. However, standard migration models for locally isothermal disk...

Kley, Willy

2011-01-01

245

Bayesian estimation in seismic migration  

OpenAIRE

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

Pitas, I.; Venetsanopoulos, A.

2010-01-01

246

Changing patterns of Ghanean Migration  

OpenAIRE

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...

Schans, Djamila; Mazzucato, Valentina; Schoumaker, Bruno; Flahaux, Marie-laurence

2013-01-01

247

Families, children, migration and AIDS  

OpenAIRE

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

248

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

249

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

250

Secondary Controlled Swing Drive  

OpenAIRE

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

251

Humics and radionuclide migration  

International Nuclear Information System (INIS)

Humic materials occur throughout the ecosphere in soils and waters, even in deep anoxic underground systems. The spectrum of molecula weights, the nature of the carbon skeleton and the types, positions and relative numbers of functional groups vary widely, in part depending on the origin and age of the humic material. Acid-base titration, C-13 CP/MAS solid-state nuclear magnetic resonance and ultrafiltration serve to define major operational characteristics of these materials. Humic materials sorb to surfaces and particulate matter in waters and can form colloids themselves. The structures and other general properties of humic substances are discussed briefly. Of importance in the migration of radionuclides in geological media is the strong complexing and redox interactions of humic materials to metal ions. The polyelectrolyte nature of humic molecules leads to very strong complexing which increases in strength with the increasing degree of ionization of the carboxylate groups. In addition, metal ions can be reduced to lower states; e.g., Pu(VI) to Pu(IV). Some unique problems are encountered in measuring the metal binding and/or redox by humic materials. However, such data is important as humic material can have significant effects on metal ion speciation and behavior in geologic systems even at 0.1 ppm levels. Measurements of actinide-humate interactions and their possible consequences on actinide migration are reviewed. (orig.)ig.)

252

Forced Migration Review  

Science.gov (United States)

Published tri-annually since January 1998, the Forced Migration Review (FMR) is the in-house journal of the Refugee Studies Centre at the University of Oxford. The journal (and its online edition made available on this site) is published in English, Arabic, and Spanish, and "provides the humanitarian community with a practice-oriented forum for debate on issues facing refugees and internally displaced people in order to improve policy and practice." From the site, visitors can browse through single articles or complete issues of the journal all the way back to 1998. Many of the issues are dedicated to a single theme, including recent issues which have been titled When does internal displacement end? and Reproductive health for displaced people: Investing in the future. The site also provides ample information on submitting articles to the journal, material on the current editorial board, and the themes for upcoming issues. Rounding out the site is a collection of related links for consideration, organized into topics such as international law, reproductive health and forced migration research institutes and centers.

253

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

Science.gov (United States)

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

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

2010-01-01

254

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

OpenAIRE

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

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

2010-01-01

255

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

Science.gov (United States)

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

Ghavidel, Ali

2015-01-01

256

Surgical clip migration following laparoscopic cholecystectomy as a cause of cholangitis  

OpenAIRE

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

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

2014-01-01

257

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

Science.gov (United States)

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

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

2014-06-01

258

Europe: Migration and Development  

Scientific Electronic Library Online (English)

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

Harris, Nigel.

2006-06-01

259

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

260

Ambient aromatic hydrocarbon measurements at Welgegund, South Africa  

Directory of Open Access Journals (Sweden)

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

K. Jaars

2014-02-01

261

Ambient aromatic hydrocarbon measurements at Welgegund, South Africa  

Energy Technology Data Exchange (ETDEWEB)

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

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

2014-07-11

262

Software Engineering Challenges of Migration Projects  

OpenAIRE

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

Geetha, S.; Dr.Alagaramy

2012-01-01

263

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

264

Dry reforming of hydrocarbon feedstocks  

Energy Technology Data Exchange (ETDEWEB)

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

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

2014-01-01

265

Proceedings of hydrocarbon contaminated soils  

International Nuclear Information System (INIS)

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

266

Catalytic method for synthesizing hydrocarbons  

Science.gov (United States)

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

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

1984-01-01

267

Liquid hydrocarbon production- where to?  

International Nuclear Information System (INIS)

The future of liquid hydrocarbon supplies and its implication for Australian are analysed, by considering what are the estimates of current crude oil reserves, what might be found in the future and where as well as the risk of relaying on import. While is expected that there is a possibility that we are moving to a liquid scarcity globally, the issue can be addressed if government policies are put in place, based on objectives of supply reliability and price competitiveness

268

Hydrocarbon prospectivity in Western Greece  

Energy Technology Data Exchange (ETDEWEB)

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

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

2012-06-15

269

Abnormal pressure in hydrocarbon environments  

Science.gov (United States)

Abnormal pressures, pressures above or below hydrostatic pressures, occur on all continents in a wide range of geological conditions. According to a survey of published literature on abnormal pressures, compaction disequilibrium and hydrocarbon generation are the two most commonly cited causes of abnormally high pressure in petroleum provinces. In young (Tertiary) deltaic sequences, compaction disequilibrium is the dominant cause of abnormal pressure. In older (pre-Tertiary) lithified rocks, hydrocarbon generation, aquathermal expansion, and tectonics are most often cited as the causes of abnormal pressure. The association of abnormal pressures with hydrocarbon accumulations is statistically significant. Within abnormally pressured reservoirs, empirical evidence indicates that the bulk of economically recoverable oil and gas occurs in reservoirs with pressure gradients less than 0.75 psi/ft (17.4 kPa/m) and there is very little production potential from reservoirs that exceed 0.85 psi/ft (19.6 kPa/m). Abnormally pressured rocks are also commonly associated with unconventional gas accumulations where the pressuring phase is gas of either a thermal or microbial origin. In underpressured, thermally mature rocks, the affected reservoirs have most often experienced a significant cooling history and probably evolved from an originally overpressured system.

Law, B.E.; Spencer, C.W.

1998-01-01

270

Topic in Depth - Bird Migration  

Science.gov (United States)

The songs of spring are in the air when migrating birds grace the skies, making regular seasonal journeys in response to alterations in weather, habitat, and food availability. The following websites cover various aspects of the amazing and ancient phenomenon of bird migration.

271

New directions for neuronal migration.  

Science.gov (United States)

Analysis of genetic mutations that lead to abnormal migration and layer formation in the developing cerebral cortex of mice and humans has led to important new discoveries regarding the molecular mechanisms that underlie these processes. Genetic manipulation and experimental analysis have demonstrated significant tangential migrations of cortical neurons, some arriving from very distant noncortical sites. PMID:9568391

Pearlman, A L; Faust, P L; Hatten, M E; Brunstrom, J E

1998-02-01

272

Radionuclide Migration: Prediction Experience  

International Nuclear Information System (INIS)

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

273

[Education and migration].  

Science.gov (United States)

This is a study of the relationship between education and internal migration in the Federal Republic of Germany, specifically the influence of educational level on the likelihood and type of move. Theoretical considerations concern regional variations in education and type of employment, feelings about location and social factors, and values and awareness of options. The theory is applied to people in the birth cohorts of 1929-1931, 1939-1941, and 1949-1951. Size of town of origin, type of schooling and year completed, distance moved, and population density of towns of origin and destination are among the factors examined. It is found that level of education is a significant determinant of spatial mobility. Results of the interplay of specific factors are discussed. PMID:12268843

Wagner, M

1987-01-01

274

HANDICRAFTS, INVASIONS AND MIGRATIONS  

Directory of Open Access Journals (Sweden)

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

Perla Shiomara del Carpio Ovando

2014-01-01

275

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

276

Radionuclide Migration Project 1984  

Science.gov (United States)

The report discusses the hydrogeologic settings and histories of studies associated with the Cheshire (U20n), Cambric (U5e), Nash (UE2ce), Bilby (U3cn), Bourbon (U7n), and Faultless (UC1) Events. Radionuclide and some chemical data are presented for water samples from cavity or chimney wells associated with the Cheshire, Cambric, and Bilby Events, and from satellite wells at the Cambric, Nash, Bibly, Bourbon, and Faultless Event sites. The report also gives the results of studies of specific sampling or analytical methodologies. These studies demonstrated that the apparent migration of (155)Eu is an artfact of spectrometric misidentification of gamma- and X-ray peaks from other constituents. A potential problem with atmospheric contamination of samples collected with evacuated thief samples was also identified. Ultrafiltration techniques were applied to some of the Cheshire cavity samples collected, and preliminary results suggest that substantial amounts of activity may be associated with colloidal particles in the size range of 0.006 to 0.45 (MU)m. A study has begun of the recharge of effluent water from RNM-25 (Cambric satellite well) into the desert floor as a result of nine years of continuous pumping. This report gives the initial results of unsaturated zone studies showing the propagation of moisture and tritium fronts through the shallow soil. Geochemical modeling of the behavior of ruthenium and technetium was carried out, with particular emphasis on the identification of ionic species that would be potentially mobile under NTS ground-water conditions. The report compares the results with observations of ruthenium migration to the Cambric satellite well.

Buddemeier, R. W.; Isherwood, D.

1985-04-01

277

Neural Crest Cell Migration  

Science.gov (United States)

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

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

2010-11-29

278

Secondary fuel delivery system  

Science.gov (United States)

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

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

2010-02-23

279

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

280

Radial migration in barred galaxies  

Science.gov (United States)

In this talk, I will present the result of high resolution numerical simulations of disk galaxies with various bulge/disk ratios evolving isolated, showing that: • Most of migration takes place when the bar strength is high and decreases in the phases of low activity (in agreement with the results by Brunetti et el. 2011, Minchev et al. 2011). • Most of the stars inside the corotation radius (CR) do not migrate in the outer regions, but stay confined in the inner disk, while stars outside CR can migrate either inwards or outwards, diffusing over the whole disk. • Migration is accompanied by significative azimuthal variations in the metallicity distribution, of the order of 0.1 dex for an initial gradient of ~-0.07 dex/kpc. • Boxy bulges are an example of stellar structures whose properties (stellar content, vertical metallicity, [?/Fe] and age gradients, ..) are affected by radial migration (see also Fig. 1).

Di Matteo, P.; Haywood, M.; Combes, F.; Semelin, B.; Babusiaux, C.; Gomez, A.

2015-03-01

281

Gender perspective in migration studies  

Directory of Open Access Journals (Sweden)

Full Text Available Research field of migration has been developing for a long time parallel to and outside mainstream institutional academic sociology and its theoretical foundation. In the last two decades, within the field of migration studies, one specific aspect of the phenomena came to the research focus: gender, as significant factor that influences on motivation for migration, shaping, at the same time, its characteristics and specific experiences. With decisive breakthrough of qualitative methods in social sciences and humanities, as well as with gradual development of postmodern philosophy and feminist theory, gender migration studies have been established as research sub-discipline, with its own theoretical and categorical scientific apparatus (as well as institutional-academic grounding, managing more or less successfully to explain and understand multidimensional character of migration processes. This text represents an attempt to make relatively concise overview of disciplines’ historical, theoretical and research field development, as a first step in its broader affirmation within Serbian institutional sociology.

Peši? Jelena

2013-01-01

282

Utilization and documentation of vertical oil migration in deep basins  

Energy Technology Data Exchange (ETDEWEB)

Use of the model of a hot, deep, origin of oil places rigid constraits on the migration and entrapment of crude oil. Specifically, oil originating from depth migrates vertically up faults and is emplaced in traps at shallower depths. Review of petroleum-producing basins worldwide shows oil occurrence in these basins conforms to the restraints of this hypothesis. Most of the world's oil is found in the very deepest sedimentary basins, and production over or adjacent to the deep basin is cut by, or directly updip from, faults dipping into the basin deep. Generally, the greater the fault throw, the great the reserves. Fault-block highs next to deep sedimentary troughs are the best target areas by the present concept. Traps along major basin-forming faults are quite prospective. The structural style of a basin governs the distribution, types, and amounts of hydrocarbons expected, and hence the exploration strategy. Production in delta depocenters (Niger) is in structures cut by or updip from major growth faults, and structures not associated with such faults are barren. Production in block-fault basins is on horsts next to deep seimentary troughs (Sirte, North Sea). In basins whose sediment thickness, structure and geologic history are known to a moderate degree, the main oil occurrences can be specifically predicted by analysis of fault systems and possible hydrocarbon migration routes. Use of the concept permits the identification of significant targets which have either been downgraded or ignored in the past, such as production in or just updip from thrust belts, stratigraphic traps over the deep basin associated with major faulting, production over the basin deep, and regional stratigraphic trapping updip from established production along major fault zones. 18 figures, 6 tables.

Price, L.C.

1980-04-01

283

DNAPL migration in a coastal plain aquifer  

International Nuclear Information System (INIS)

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

284

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 gre 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

285

Migrating and herniating hydatid cysts  

Energy Technology Data Exchange (ETDEWEB)

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.

Koc, Zafer [Baskent University, Faculty of Medicine, Department of Radiology, Adana (Turkey)], E-mail: koczafer@gmail.com; Ezer, Ali [Baskent University, Faculty of Medicine, Department of Surgery, Adana (Turkey)

2008-01-15

286

Hydrocarbon potential of Altiplano and northern Subandean, Bolivia  

Energy Technology Data Exchange (ETDEWEB)

Seismic, stratigraphic, structural, and geochemical data from the Altiplano, northern Subandean, and northern plains of Bolivia were interpreted in order to evaluate the exploration potential of each province. Identification of three possible source rock intervals, primarily the Devonian and secondarily the Permian and Cretaceous, was used as the basis for recognizing active hydrocarbon systems. For those areas containing source intervals, their analysis revealed that possible reservoir and seal units range in age from Paleozoic to Tertiary; the majority of structures, however, are Eocene or younger. With these general concepts in mind, traps were identified in all three sedimentary provinces. In the northern Altiplano, the most prospective area is along the eastern margin near a southwest and west-vergent thrust belt where hanging-wall anticlines and a warped Eocene-Oligocene(.) unconformity surface form the most likely potential traps. In the central and southern Altiplano, both thrust-related and wrench-related structures present possible exploration targets. In the northern Subandean and Beni plains north of the Isiboro-Chapare area, traps can be classified into two broad groups. First, there are a wide variety of structural traps within the northern Subandean thrust belt, the most attractive of which are footwall structures that have been shielded from surface flushing by hanging-wall strata. Second, in the plains just northeast of the thrust belt, hydrocarbons sourced from the remnant Paleozoic basin may have migrated onto the Isarsama and Madidi highs.

Edman, J.D.; Kirkpatrick, J.R.; Lindsey, D.D.; Lowell, J.D.; Cirbian, M.; Lopez, M.

1989-03-01

287

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...

288

Microbial degradation of hydrocarbons in the environment.  

OpenAIRE

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

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

1990-01-01

289

Oil based synthetic hydrocarbon drilling fluid  

International Nuclear Information System (INIS)

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

290

Green Methodologies to Test Hydrocarbon Reservoirs  

OpenAIRE

Problem statement: The definition and the economic viability of the best development strategy of a hydrocarbon reservoir mainly depend on the quantity and type of fluids and on the well productivity. Well testing, consisting in producing hydrocarbon to the surface while measuring the pressure variations induced in the reservoir, has been used for decades to determine the fluid nature and well potential. In exploration and appraisal scenarios the hydrocarbons produced during a test are flared,...

Francesca Verga; Vera Rocca

2010-01-01

291

Physiology of aliphatic hydrocarbon-degrading microorganisms.  

Science.gov (United States)

This paper reviews aspects of the physiology and biochemistry of the microbial biodegradation of alkanes larger than methane, alkenes and alkynes with particular emphasis upon recent developments. Subject areas discussed include: substrate uptake; metabolic pathways for alkenes and straight and branched-chain alkanes; the genetics and regulation of pathways; co-oxidation of aliphatic hydrocarbons; the potential for anaerobic aliphatic hydrocarbon degradation; the potential deployment of aliphatic hydrocarbon-degrading microorganisms in biotechnology. PMID:1368149

Watkinson, R J; Morgan, P

1990-01-01

292

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

293

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

294

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

OpenAIRE

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...

Kleindienst, Sara

2012-01-01

295

New technique for calibrating hydrocarbon gas flowmeters  

Science.gov (United States)

A technique for measuring calibration correction factors for hydrocarbon mass flowmeters is described. It is based on the Nernst theorem for matching the partial pressure of oxygen in the combustion products of the test hydrocarbon, burned in oxygen-enriched air, with that in normal air. It is applied to a widely used type of commercial thermal mass flowmeter for a number of hydrocarbons. The calibration correction factors measured using this technique are in good agreement with the values obtained by other independent procedures. The technique is successfully applied to the measurement of differences as low as one percent of the effective hydrocarbon content of the natural gas test samples.

Singh, J. J.; Puster, R. L.

1984-01-01

296

Nox reduction system utilizing pulsed hydrocarbon injection  

Science.gov (United States)

Hydrocarbon co-reductants, such as diesel fuel, are added by pulsed injection to internal combustion engine exhaust to reduce exhaust NO.sub.x to N.sub.2 in the presence of a catalyst. Exhaust NO.sub.x reduction of at least 50% in the emissions is achieved with the addition of less than 5% fuel as a source of the hydrocarbon co-reductants. By means of pulsing the hydrocarbon flow, the amount of pulsed hydrocarbon vapor (itself a pollutant) can be minimized relative to the amount of NO.sub.x species removed.

Brusasco, Raymond M. (Livermore, CA); Penetrante, Bernardino M. (San Ramon, CA); Vogtlin, George E. (Fremont, CA); Merritt, Bernard T. (Livermore, CA)

2001-01-01

297

Detection of hydrocarbons in irradiated foods  

International Nuclear Information System (INIS)

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

298

Population commission discusses international migration.  

Science.gov (United States)

At the 30th session of the Commission on Population and Development during February 24-28, 1997, international migration was the main topic, with special linkages between migration and development and on gender issues and the family. New and emerging issues were also considered. Members stressed the need for more reliable data on migration, the direction of migrants flows, and the characteristics of migrants. The Commission requested a task force on basic social services to hold a technical symposium of experts on international migration in 1998. Its chair, Dr. Nafis Sadik, said that migration issues should based on the reality of choice not on coercive measures or quotas. Almost half of the migrants globally are women. The Commission was given a new impetus by the International Conference on Population and Development held at Cairo in 1994. Migration pressures intensified in the second half of the 1980s and in the early 1990s, creating areas of concern: the negative impact of short-term migration on working conditions in host countries; migration pressures emanating from climatic change; the protection of migrant women and their children; the right of receiving countries to regulate access to their territory; the adverse consequences of forced migration; the situation of persons whose asylum claims have been rejected; the trafficking in women and children, prostitution and coercive adoption; and the sudden and massive arrival of refugees in need of international protection. The 1998 session of the Commission will feature the theme of health and mortality, with special emphasis on the linkages between health and development and on gender and age. PMID:12292475

1997-01-01

299

"Global Migration Patterns" Lesson Plan  

Science.gov (United States)

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

300

New directions in neuronal migration.  

Science.gov (United States)

Over the past decade, genetic analyses have yielded a more molecular view of neuronal migration and its role in central nervous system development. We now realize that many of the molecular mechanisms that guide migrations in invertebrates are recapitulated in the vertebrate nervous system. These mechanisms guide dorsoventral and anterior-posterior migrations and merge with radial migratory pathways that are prominent in the development of the mammalian cortex. This review discusses the choreography of these different migratory mechanisms within the context of genetic approaches that have defined their molecular mechanisms. PMID:12215636

Hatten, Mary E

2002-09-01

301

Full wavefield migration: utilization of multiples in seismic migration:  

OpenAIRE

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

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

2012-01-01

302

Rebooting migration theory: Interdisciplinarity, globality and postdisciplinarity in migration studies  

OpenAIRE

It is no small ambition to bring together a comprehensive overview of contemporary migration theory across the social sciences and humanities. Such has been the explosion of interest in international migration in the past decade or so that no scholar nowadays can feel adequate when confronting the avalanche of literature that has followed. The rather heroic enterprise presented here has the virtue of letting disciplinary perspectives speak for themselves in a congenial dialogue, rather than a...

Favell, Adrian

2007-01-01

303

Radionuclide migration in soils  

International Nuclear Information System (INIS)

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

304

Basic neutronics. Neutrons migration  

International Nuclear Information System (INIS)

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

305

Secondary extinctions of biodiversity.  

Science.gov (United States)

Extinctions beget further extinctions when species lose obligate mutualists, predators, prey, or hosts. Here, we develop a conceptual model of species and community attributes affecting secondary extinction likelihood, incorporating mechanisms that buffer organisms against partner loss. Specialized interactors, including 'cryptic specialists' with diverse but nonredundant partner assemblages, incur elevated risk. Risk is also higher for species that cannot either evolve new traits following partner loss or obtain novel partners in communities reorganizing under changing environmental conditions. Partner loss occurs alongside other anthropogenic impacts; multiple stressors can circumvent ecological buffers, enhancing secondary extinction risk. Stressors can also offset each other, reducing secondary extinction risk, a hitherto unappreciated phenomenon. This synthesis suggests improved conservation planning tactics and critical directions for research on secondary extinctions. PMID:25445878

Brodie, Jedediah F; Aslan, Clare E; Rogers, Haldre S; Redford, Kent H; Maron, John L; Bronstein, Judith L; Groves, Craig R

2014-12-01

306

Secondary chondrosarcoma: radiopathological correlation.  

Science.gov (United States)

Chondrosarcomas are malignant bone tumors originating in cartilage. Chondrosarcoma is the third most common malignant bone tumor after multiple myeloma and osteosarcoma. About 75% of chondrosarcomas are primary lesions. The remaining 25% belong to special categories such as histologic variants and secondary forms. A secondary chondrosarcoma is one that appears in a pre-existing benign chondral lesion; the different types of secondary chondrosarcomas include solitary osteochondroma, multiple osteochondromatosis, enchondroma, the different types of enchondromatosis, and primary synovial chondromatosis. The incidence of this malignant transformation varies widely in function of the type of lesion. In this article, we discuss and illustrate the different types of secondary chondrosarcomas, placing special emphasis on the imaging findings that should alert to these lesions and give radiologists a key role in the diagnosis, management, and follow-up of these patients. PMID:25002353

Lozano Martínez, G A; Llauger Rosselló, J

2014-07-01

307

Primary and Secondary Qualities.  

Czech Academy of Sciences Publication Activity Database

New York : Continuum, 2010 - ( Savonius -Wroth, S.; Schuurman, P.; Walmsley, J.), s. 199-201 ISBN 9780826428110 Institutional research plan: CEZ:AV0Z90090514 Keywords : primary and secondary qualities * Locke * corpuscularianism Subject RIV: AA - Philosophy ; Religion

Hill, James

308

Composition of the surface hydrocarbons from the vitelline membranes of dipteran embryos.  

Science.gov (United States)

Hydrocarbons were the major lipid class extracted by hexane from the vitelline membrane surface of dechorionated eggs of the house fly, Musca domestica, the New World screwworm, Cochliomyia hominivorax, the secondary screwworm, Cochliomyia macellaria, the green bottle fly, Phaenicia sericata, the sheep blow fly, Lucilia cuprina and the Mexican fruit fly, Anastrepha ludens. The length of time the embryos must be exposed to hexane with or without a small amount of alcohol in order to attain permeability was species-dependant. Long-chain n-alkanes comprised the major lipid class removed from vitelline membranes of all species except A. ludens where 2-methylalkanes were the major class. The range in size by the total number of carbon atoms in the hydrocarbons was: C23-C49 in C. hominivorax, C27-C33 in C. macellaria, C24-C35 in L. cuprina, C25-C36 in M. domestica, C25-C33 in P. sericata and C21-C51 in A. ludens. The major hydrocarbon component, expressed as percent of the total hydrocarbons, was n-nonacosane (C29) in C. hominivorax (40%), C. macellaria (43%), L. cuprina (38%), M. domestica (39%) and P. sericata (60%). However, in A. ludens, 2-methyloctacosane (32%) was the major hydrocarbon. Unsaturated hydrocarbons, monoenes (16%) and dienes (11%), were abundant only in A. ludens. Since prior studies indicated that the length of time the embryos must be exposed to hexane with or without a small amount of alcohol in order to attain permeability is species dependant, we suggest that the differences in hydrocarbon composition may contribute to this variation in lipid extractability. PMID:14529755

Nelson, Dennis R; Leopold, Roger A

2003-10-01

309

Applied bioremediation of petroleum hydrocarbons  

International Nuclear Information System (INIS)

This volume is part of a ten volume set of papers derived from the Third International In Situ and On-Site Bioreclamation Symposium which was held in San Diego, California, in April 1995. The purpose of the conference was to provide a multidisciplinary forum for exchange of state-of-the-art information on bioremediation. The papers in this volume focus on petroleum hydrocarbon bioremediation, with an emphasis on pilot-scale and field-scale applications. Individual papers have been processed separately for inclusion in the appropriate data bases

310

Applied bioremediation of petroleum hydrocarbons  

Energy Technology Data Exchange (ETDEWEB)

This volume is part of a ten volume set of papers derived from the Third International In Situ and On-Site Bioreclamation Symposium which was held in San Diego, California, in April 1995. The purpose of the conference was to provide a multidisciplinary forum for exchange of state-of-the-art information on bioremediation. The papers in this volume focus on petroleum hydrocarbon bioremediation, with an emphasis on pilot-scale and field-scale applications. Individual papers have been processed separately for inclusion in the appropriate data bases.

Hinchee, R.E.; Kittel, J.A. [eds.] [Battelle Memorial Inst., Columbus, OH (United States); Reisinger, H.J. [ed.] [Integrated Science and Technology, Inc., Marietta, GA (United States)

1995-12-31

311

Nitrogen analogues of Thiele's hydrocarbon.  

Science.gov (United States)

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

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

2015-01-26

312

Bacteriophage secondary infection.  

Science.gov (United States)

Phages are credited with having been first described in what we now, officially, are commemorating as the 100(th) anniversary of their discovery. Those one-hundred years of phage history have not been lacking in excitement, controversy, and occasional convolution. One such complication is the concept of secondary infection, which can take on multiple forms with myriad consequences. The terms secondary infection and secondary adsorption, for example, can be used almost synonymously to describe virion interaction with already phage-infected bacteria, and which can result in what are described as superinfection exclusion or superinfection immunity. The phrase secondary infection also may be used equivalently to superinfection or coinfection, with each of these terms borrowed from medical microbiology, and can result in genetic exchange between phages, phage-on-phage parasitism, and various partial reductions in phage productivity that have been termed mutual exclusion, partial exclusion, or the depressor effect. Alternatively, and drawing from epidemiology, secondary infection has been used to describe phage population growth as that can occur during active phage therapy as well as upon phage contamination of industrial ferments. Here primary infections represent initial bacterial population exposure to phages while consequent phage replication can lead to additional, that is, secondary infections of what otherwise are not yet phage-infected bacteria. Here I explore the varying meanings and resultant ambiguity that has been associated with the term secondary infection. I suggest in particular that secondary infection, as distinctly different phenomena, can in multiple ways influence the success of phage-mediated biocontrol of bacteria, also known as, phage therapy. PMID:25595214

Abedon, Stephen T

2015-02-01

313

Mechanisms and modelling of gas migration from deep radioactive waste repositories  

International Nuclear Information System (INIS)

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

314

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

315

Remote Sensing Detecting for Hydrocarbon Microseepage and Relationship with the Uranium Mineralization in Dongsheng Area, Ordos Basin, China  

Science.gov (United States)

The Ordos Basin is located at the central area of northern China with an area of about 250,000 km2. It is well known "a basin of energy resources" of China for its large reserves of coal, oil and gas. A large-scale sandstone-type uranium metallogenic belt has been found recently in Zhiluo Formation of middle Jurassic in Dongsheng area in the northeastern part of the basin. The ore-forming mechanism remains unsolved so far. There is a hypothesis that the uranium precipitation was related to a hydrocarbon migration from the central basin. In order to explore the evidences of ever existed hydrocarbon microseepage and migration in this area, several indices such as the Iron Oxide Index, Ferrous Index, Clay Mineral Index, Mineral Composite Index, and Ferrous Transfer Percentage Index have been derived. Thorium Normalization of aeroradiometric data and fusion of aeroradiometric and TM data have been carried out as well. Therefore, the subaerial oxide and reduced area, uranium outmigrated and immigrated area, and ancient recharge and discharge of groundwater are thus delineated. As a result, two hydrocarbon microseepage belts in Dongsheng area have been extracted by combining the methods mentioned above. One is in the northern of Dongsheng along a nearly east-westward fault zone and the other one is in the southern of Dongsheng uranium mineralization belt along a nearly northwestward fault zone. The study suggests that the subaerial reduced area was related to hydrocarbon microseepage and the hydrocarbon migration along the fault and fracture zone or penetrable strata played an important role for uranium deposition in Zhiluo Formation near the northwestward fault zone.

Zhu, M.; Liu, D.; Gao, Y.

2005-12-01

316

40 CFR 86.317-79 - Hydrocarbon analyzer specifications.  

Science.gov (United States)

... § 86.317-79 Hydrocarbon analyzer specifications. (a) Hydrocarbon measurements are to...FID) that measures hydrocarbon emissions on a dry basis is permitted...produces comparable results to an HFID not...

2010-07-01

317

40 CFR 52.987 - Control of hydrocarbon emissions.  

Science.gov (United States)

...1980. This shall result in an estimated hydrocarbon emission reduction of at...1980. This shall result in an estimated hydrocarbon emission reduction of at...1978. This shall result in an estimated hydrocarbon emission reduction of...

2010-07-01

318

“INTERNATIONAL MIGRATION AND INTERCULTURAL COMMUNICATION”  

Directory of Open Access Journals (Sweden)

Full Text Available Movement of the people, either individually or massive, between cities, regions and countries still continue from history to today. Since the economic system has become internationally widespread through globalization, improvement of communication and transportation technologies have increased the movements of people between countries and long-term settlements as called migration. Today, through the size that international migration has gained, more people who have been raised in different cultures are getting, working and living together. The international migration brings cultural adaption problems which occurs together with interaction of people from different cultures. In this regard, it is seen that the importance of the intercultural communication discipline has improved. In this study, it is approached to the international migration phenomenon with the concepts of intercultural communication, and the role of intercultural communication is analyzed.

Zeynep AKSOY

2015-03-01

319

Data Migration Across The Clouds  

Directory of Open Access Journals (Sweden)

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

Prashant Pant,

2013-05-01

320

The migration challenge for PAYG.  

Czech Academy of Sciences Publication Activity Database

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

Aslanyan, Gurgen

2014-01-01

321

The migration challenge for PAYG.  

Czech Academy of Sciences Publication Activity Database

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

Aslanyan, Gurgen

2014-01-01

322

Fluid migration studies in salt  

International Nuclear Information System (INIS)

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

323

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.)

324

Palaearctic-African Bird Migration  

DEFF Research Database (Denmark)

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

Iwajomo, Soladoye Babatola

2013-01-01

325

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

326

Does Higher Education Enhance Migration?  

OpenAIRE

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

Haapanen, Mika; Bo?ckerman, Petri

2013-01-01

327

Essays on Growth and Migration  

OpenAIRE

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

328

Migration to the public cloud  

OpenAIRE

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

Wang, Tong

2013-01-01

329

Macrostabilization of the Migration Phenomenon  

OpenAIRE

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

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

2014-01-01

330

Cell Biology of Embryonic Migration  

OpenAIRE

Cell migration is an evolutionarily conserved mechanism that underlies the development and functioning of uni- and multicellular organisms and takes place in normal and pathogenic processes, including various events of embryogenesis, wound healing, immune response, cancer metastases, and angiogenesis. Despite the differences in the cell types that take part in different migratory events, it is believed that all of these migrations occur by similar molecular mechanisms, whose major components ...

Kurosaka, Satoshi; Kashina, Anna

2008-01-01

331

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)

332

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

333

Cell biology of embryonic migration.  

Science.gov (United States)

Cell migration is an evolutionarily conserved mechanism that underlies the development and functioning of uni- and multicellular organisms and takes place in normal and pathogenic processes, including various events of embryogenesis, wound healing, immune response, cancer metastases, and angiogenesis. Despite the differences in the cell types that take part in different migratory events, it is believed that all of these migrations occur by similar molecular mechanisms, whose major components have been functionally conserved in evolution and whose perturbation leads to severe developmental defects. These mechanisms involve intricate cytoskeleton-based molecular machines that can sense the environment, respond to signals, and modulate the entire cell behavior. A big question that has concerned the researchers for decades relates to the coordination of cell migration in situ and its relation to the intracellular aspects of the cell migratory mechanisms. Traditionally, this question has been addressed by researchers that considered the intra- and extracellular mechanisms driving migration in separate sets of studies. As more data accumulate researchers are now able to integrate all of the available information and consider the intracellular mechanisms of cell migration in the context of the developing organisms that contain additional levels of complexity provided by extracellular regulation. This review provides a broad summary of the existing and emerging data in the cell and developmental biology fields regarding cell migration during development. PMID:18546335

Kurosaka, Satoshi; Kashina, Anna

2008-06-01

334

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

Science.gov (United States)

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

Veerman, Gert-Jan M.

2015-01-01

335

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

Science.gov (United States)

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

Raznitsin, Yu. N.

2012-01-01

336

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

International Nuclear Information System (INIS)

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

337

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

338

Hydrocarbon Collision Database: Revisions, Upgrades and Extensions  

International Nuclear Information System (INIS)

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

339

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. 5 Figs.

Greenbaum, E.

1995-05-23

340

Distance and Intrastate College Student Migration  

Science.gov (United States)

Most studies of student migration focus on "interstate" migration of college students, largely because the aggregate data typically used are limited in geographic specificity to states. However, interstate migration is only a small part of the total student migration. Public institutions generally get most of their students from within their…

Alm, James; Winters, John V.

2009-01-01

341

Rural-Urban Migration in Colombia.  

Science.gov (United States)

The rural-urban migration pattern in Colombia during the last 25 years has resulted in a population increase in urban areas from 30 to 52 percent of the total population. This study explores the causes of internal migration. Migration rates are estimated for various groups in the population to clarify who migrates and to where. A model of…

Schultz, T. Paul

342

Hydrocarbon pretreatment process for catalytic cracking  

Energy Technology Data Exchange (ETDEWEB)

A process is described for pretreating heavy hydrocarbon feedstock for use as a feed in the production of liquid hydrocarbon fuels consisting of: (a) delivering the heavy hydrocarbon feedstock to a tubular thermal pretreating reactor; (b) delivering hot particulate solids to the tubular thermal pretreating reactor; (c) pretreating the heavy hydrocarbon feedstock at a temperature between 1050/sup 0/F and 1200/sup 0/F; and a residence time of 0.20 to 0.50 seconds wherein the heavy hydrocarbon feedstock is vaporized thereby forming a pretreated gas, (d) separating the pretreated gas from the particulate solids; (e) immediately delivering the separated pretreated gas from the thermal pretreating reactor to a catalytic reactor; and (f) catalytically cracking the pretreated effluent from the thermal cracking reactor.

Gartside, R.J.; Johnson, A.R.; Ross, J.L.; Duncan, D.A.; Bassler, E.J.

1986-04-29

343

Olefin production from heavy hydrocarbon feed  

Energy Technology Data Exchange (ETDEWEB)

A process is described for producing olefins and liquid hydrocarbon fuels from heavy hydrocarbon residual oil feed comprising: delivering a hydrocarbon side cut from a coker fractionation tower to a tubular thermal regenerative cracking reactor feeder; delivering hot particulate solids to the tubular thermal regenerative cracking reactor feeder; delivering the mixed hot particulate solid and the hydrocarbon side cut from the coker fractionation tower to the tubular thermal regenerative cracking reactor; separating the cracked effluent and the particulate solids discharged from the tubular thermal regenerative cracking reactor; injecting the heavy hydrocarbon residual oil feed into the cracked effluent stream to quench the cracked effluent stream; delivering the quenched cracked effluent stream to the coker fractionation tower; and producing coke from the bottoms of the coker fractionation tower.

Gartside, R.J.; Johnson, A.R.; Ross, J.L.; Duncan, D.A.

1987-05-05

344

Private sector perspectives on hydrocarbon contamination  

International Nuclear Information System (INIS)

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

345

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

International Nuclear Information System (INIS)

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

346

Geochemical evaluation of the hydrocarbon prospects of sedimentary basins in Northern Nigeria  

Energy Technology Data Exchange (ETDEWEB)

Sedimentary basins of Northern Nigeria comprise the Middle and Upper Benue Trough, the southeastern sector of the Chad Basin, the Mid-Niger (Bida) Basin, and the Sokoto Basin. Organic geochemical and organic petrologic studies indicate the existence of potential source rocks in the Benue Trough and the Chad Basin, with coal beds constituting major potential source rocks in the whole of the Benue Trough. The generation and production of liquid and gaseous hydrocarbons from coal beds presently is world-wide indisputable. Although TOC values and liptinite contents are relatively high in the Mid-Niger (Bida) Basin, Tmax values and biomarker data show that hydrocarbons are probably just being generated in the basin and may not yet have been expelled nor migrated in large quantities.

Obaje, N.G.; Attah, D.O.; Opeloye, S.A.; Moumouni, A. [Nasarawa State University, Keffi (Nigeria). Dept. Geology & Minerals

2006-07-01

347

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1981-01-01

348

Migration and the Option Value of Waiting  

OpenAIRE

Migration is an investment: it involves fixed, unrecoverable costs and uncertain future returns. If migration can be postponed, the option value of doing so may have positive value. Migration may not occur for a range of individuals who would otherwise migrate on a net present value basis. This paper models the migration decision using ideas developed by Pindyck (1991) and Dixit (1992). The option value of waiting is related to the interest rate, fixed costs, and especially uncertainty govern...

Burda, Michael C.

1995-01-01

349

Improved Live Migration Using Compressed Log Files  

OpenAIRE

Live virtual machine migration is the process of moving virtual machine from one host to other without disturbance of users. Live migration is used in the case of proactive maintenance, power management, load balancing, energy saving. This paper present and design the novel approach to reduce the total migration time and down time during live virtual machine migration by compressed log files transfer. For providing the effective and fast migration of the virtual machine log compression method...

Rakhi K Raj, Getzi Jeba Leelipushpam

2013-01-01

350

Polycyclic aromatic hydrocarbons in waste derived pyrolytic oils  

Energy Technology Data Exchange (ETDEWEB)

Waste material in the form of wood waste, municipal solid waste and rice husks was pyrolysed in a gas-purged static batch reactor and a fluidised bed reactor. The condensed pyrolytic oils were analysed for their content of polycyclic aromatic hydrocarbons (PAH). The oils were fractionated into chemical classes using mini-column liquid chromatography followed by analysis using GC/FID and GC/MS for identification and quantitation of PAH. The waste derived oils were found to contain substantial concentrations of PAH, which were formed via secondary Diels-Alder and deoxygenation reactions. The concentrations of PAH were influenced by reactor temperature and residence time. The PAH consisted mainly of naphthalene, fluorene and phenanthrene and their alkylated homologues, but also included some PAH which were of known carcinogenic or mutagenic activity

Williams, Paul T.; Besler, Serpil (Dept. of Fuel and Energy, The Univ. of Leeds, Leeds (United Kingdom))

1994-10-01

351

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

352

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

Science.gov (United States)

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

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

2011-12-01

353

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

354

Stability of conjugated hydrocarbon ions  

International Nuclear Information System (INIS)

The authors consider the question of predicting the stability of hypothetical structures that are too large for ab initio calculations, too complex for simple MO calculations, and too few for reliable semiempirical SCF MO schemes. The problem is illustrated on a polycyclic conjugated cation having 21 carbon atoms. The analysis is general and applies to conjugated hydrocarbons and their ions for which it is not apparent whether they exhibit aromatic characteristics (and, if they do, to what extent). For the investigated polycyclic cation they find that to a large extent its aromatic components are canceled by its antiaromatic components resulting in an essentially nonaromatic system. The analysis, which is based on close examination of various contributing conjugated circuits, allows one to examine the partial role of the individual Kekule valence structures as well as to foretell the nature of both the positively and negatively charged system

355

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

356

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

357

Fate of hydrocarbons in solids  

International Nuclear Information System (INIS)

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

358

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.)

359

Seasonal survival probabilities suggest low migration mortality in migrating bats.  

Science.gov (United States)

Migration is adaptive if survival benefits are larger than costs of residency. Many aspects of bat migration ecology such as migratory costs, stopover site use and fidelity are largely unknown. Since many migrating bats are endangered, such information is urgently needed to promote conservation. We selected the migrating Leisler's bat (Nyctalus leisleri) as model species and collected capture-recapture data in southern Switzerland year round during 6 years. We estimated seasonal survival and site fidelity with Cormack-Jolly-Seber models that accounted for the presence of transients fitted with Bayesian methods and assessed differences between sexes and seasons. Activity peaked in autumn and spring, whereas very few individuals were caught during summer. We hypothesize that the study site is a migratory stopover site used during fall and spring migration for most individuals, but there is also evidence for wintering. Additionally, we found strong clues for mating during fall. Summer survival that included two major migratory journeys was identical to winter survival in males and slightly higher in females, suggesting that the migratory journeys did not bear significant costs in terms of survival. Transience probability was in both seasons higher in males than in females. Our results suggest that, similarly to birds, Leisler's bat also use stopover sites during migration with high site fidelity. In contrast to most birds, the stopover site was also used for mating and migratory costs in terms of survival seemed to be low. Transients' analyses highlighted strong individual variation in site use which makes particularly challenging the study and modelling of their populations as well as their conservation. PMID:24454906

Giavi, Simone; Moretti, Marco; Bontadina, Fabio; Zambelli, Nicola; Schaub, Michael

2014-01-01

360

Seasonal Survival Probabilities Suggest Low Migration Mortality in Migrating Bats  

Science.gov (United States)

Migration is adaptive if survival benefits are larger than costs of residency. Many aspects of bat migration ecology such as migratory costs, stopover site use and fidelity are largely unknown. Since many migrating bats are endangered, such information is urgently needed to promote conservation. We selected the migrating Leisler's bat (Nyctalus leisleri) as model species and collected capture-recapture data in southern Switzerland year round during 6 years. We estimated seasonal survival and site fidelity with Cormack-Jolly-Seber models that accounted for the presence of transients fitted with Bayesian methods and assessed differences between sexes and seasons. Activity peaked in autumn and spring, whereas very few individuals were caught during summer. We hypothesize that the study site is a migratory stopover site used during fall and spring migration for most individuals, but there is also evidence for wintering. Additionally, we found strong clues for mating during fall. Summer survival that included two major migratory journeys was identical to winter survival in males and slightly higher in females, suggesting that the migratory journeys did not bear significant costs in terms of survival. Transience probability was in both seasons higher in males than in females. Our results suggest that, similarly to birds, Leisler's bat also use stopover sites during migration with high site fidelity. In contrast to most birds, the stopover site was also used for mating and migratory costs in terms of survival seemed to be low. Transients' analyses highlighted strong individual variation in site use which makes particularly challenging the study and modelling of their populations as well as their conservation. PMID:24454906

Giavi, Simone; Moretti, Marco; Bontadina, Fabio; Zambelli, Nicola; Schaub, Michael

2014-01-01

361

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

362

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

Science.gov (United States)

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

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

2014-10-30

363

Secondary homotopy groups  

OpenAIRE

Secondary homotopy groups supplement the structure of classical homotopy groups. They yield a track functor on the track category of pointed spaces compatible with fiber sequences, suspensions and loop spaces. They also yield algebraic models of homotopy types with homotopy groups concentrated in two consecutive dimensions.

Baues, Hans-joachim; Muro, Fernando

2006-01-01

364

[Secondary bronchogenic pulmonary hydatidosis].  

Science.gov (United States)

Secondary bronchogenic hydatid disease is a rare and little known complication of primary hydatid cyst of the lung, which is even refuted by some authors. We report 7 cases of secondary bronchogenic hydatid after surgical cure of a hydatid cyst which had ruptured into the bronchi, while the last case concerned a young girl who was treated by corticosteroids for rheumatoid arthritis and who developed secondary bronchogenic hydatid from a cyst rupturing into the bronchi in the absence of surgery. Hydatid dissemination was ipsilateral to the primary cyst in 5 cases, controlateral in one case and bilateral in one case. Five patients underwent radical surgery. The patient with bilateral dissemination was operated on one side and a large number of residual cysts were eliminated by vomica, as for the last patient; these two patients are still under surveillance. The operation and general anaesthesia played a predisposing role in the pathogenesis of this complication and inhibition of immune mechanisms could also play a role. Prevention is necessary when treating a hydatid cyst of the lung which has ruptured into the bronchi. Treatment is surgical, bearing in mind that a large number of secondary cysts can be eliminated by vomica or may involute spontaneously. PMID:1605539

Kilani, T; Horchani, H; Daoues, A

1992-01-01

365

Secondary emission gas chamber  

CERN Document Server

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

In'shakov, V; Skvortsov, V

2014-01-01

366

Migration from and to Palestine from a gender perspective: results from the Migration Survey – 2010  

OpenAIRE

Migration has gained in importance in recent years due to significantly increased migration rates, in addition to the effect of migration on various population structures such as age, gender and marital status in both sending and receiving countries. This paper aims to look at the recent patterns of migration from and to the occupied Palestinian territory (oPt) in terms of size, characteristics, remittances, migration determinants, return migration, etc. To this objective, data ha...

Duraidi, Mohammed

2011-01-01

367

The Role of Remittances in Migration Decision: Evidence from Turkish Migration  

OpenAIRE

In this study we analyse the impact of workers' remittances on the decision to migrate by means of cointegration analysis. In traditional migration theories, especially in human capital models, the decision to migrate is based upon comparison of expected future incomes in the sending and the receiving countries adjusted for the cost of migration. By contrast, the new economics of labour migration suggests that the migration decision is made jointly by the migrant and his family. One important...

Akkoyunlu, Sule; Siliverstovs, Boriss

2007-01-01

368

Migrating lumbar facet joint cysts  

Energy Technology Data Exchange (ETDEWEB)

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

Palmieri, Francesco; Cassar-Pullicino, Victor N.; Lalam, Radhesh K.; Tins, Bernhard J.; Tyrrell, Prudencia N.M.; McCall, Iain W. [Robert Jones and Agnes Hunt Orthopaedic and District Hospital, Department of Radiology, Oswestry (United Kingdom)

2006-04-15

369

The offshore hydrocarbon releases (HCR) database  

International Nuclear Information System (INIS)

Following Cullen Recommendation 39 which states that: ''The regulatory body should be responsible for maintaining a database with regard to hydrocarbon leaks, spills, and ignitions in the Industry and for the benefit of Industry'', HSE Offshore Safety Division (HSE-OSD) has now been operating the Hydrocarbon Releases (HCR) Database for approximately 3 years. This paper deals with the reporting of Offshore Hydrocarbon Releases, the setting up of the HCR Database, the collection of associated equipment population data, and the main features and benefits of the database, including discussion on the latest output information. (author)

370

Waste Plastic Converting into Hydrocarbon Fuel Materials  

Energy Technology Data Exchange (ETDEWEB)

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

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

2010-09-15

371

Detection of irradiated meats by hydrocarbon method  

International Nuclear Information System (INIS)

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

372

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

373

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

374

One-way wave-equation migration for wide-angle propagation in anisotropic media  

Energy Technology Data Exchange (ETDEWEB)

Seismic depth migration is a major component in the search for hydrocarbons. As new prospects for oil and gas often are found in areas with challenging subsurface structures, more advanced methods to find and evaluate these prospects are needed. One-way wave-equation migration provides an appealing approach to be used to create an image of the subsurface. The characteristics of wave propagation can be described through the dispersion relation, relating the vertical and horizontal phase-slowness. In the first part of this thesis, simple and accurate phase-slowness approximations valid for wide-angle propagation in a VTI media are derived. Information from the subsurface might be increased by recording converted wave reflections in addition to pressure waves. The second part of this thesis provides the development of a set of new one-way propagators for imaging steeply dipping and complex structures using converted and pressure waves in a VTI medium. Reliable amplitude information from one-way methods is useful as hydrocarbon indicators in structural imaging and for migration velocity analysis. In the third part of this thesis, a flux-normalized wavefield decomposition is used as a starting point to develop one-way propagators with improved amplitudes. In new exploration areas, salt structures are important examples of subsurface complexity. This poses a challenge for one-way migration methods due to large velocity contrasts between salt and the surrounding sediments. A novel approach using one-way migration operators combined with a lateral windowing construction to limit the impact of errors introduced by large velocity contrasts is developed. (Author)

Pedersen, Oerjan

2010-07-15

375

Episodic migration of natural gas: A worldwide phenomenon of dynamic filling of oil and gas fields  

Energy Technology Data Exchange (ETDEWEB)

Natural gases form through bacterial and thermogenic conversion of organic matter over extended geological time. The isotopic properties of methane and C2+hydrocarbons are controlled by temperature dependent kinetic fractionation during maturation and mixing during migration and in reservoirs. Gas fields which are actively and repeatedly charged over extended periods of gas formation will receive compositionally and isotopically variable charges of natural gases that can mix in different proportions in single reservoirs. Episodic migration and multiple filling of reservoirs is a ubiquitous phenomenon observed in small and giant gas fields throughout the world. The following case histories from own research and from the literature will be discussed to illustrate this phenomenon: Gulf of Mexico: Pervasive mixing of bacterial and thermogenic gas charges results in large variations in isotopic signatures on a field and reservoir scale. Major formation and migration episodes are (1) Bacterial gases form in rapidly subsiding mini basins and migrate and accumulate around rising sell structures and active growth faults and (2) Following multiple charges of thermogenic gases mix in various proportions with bacterial gases. Angola: Giant oil fields off-shore Cabinda contain thermogenic gases with different isotopic signatures in the gas cap and the oil leg, indicating a multi phase migration of thermogenic; gases from mature to post-mature sources. The gas/oil columns are in some cases variable and suggest compartmentalization and/or unmixed oil hydrocarbon columns. Yacheng Gas Field: Gas composition and isotopic signatures of methane change from west to east in this giant field in the S. China Sea. Inert gas contents also vary vertically in the reservoir suggesting a late charge of a CO[sub 2] rich gas into the structure. South ltaly. Pliocene reservoirs in the Apulian Basin are mixtures of thermogenic and bacterial gases.

Schoell, M. (Chevron Petroleum Technology Co., La Habra, CA (United States)); Beeunas, M.A. (Chevron USA, New Orleans, LA (United States))

1996-01-01

376

Episodic migration of natural gas: A worldwide phenomenon of dynamic filling of oil and gas fields  

Energy Technology Data Exchange (ETDEWEB)

Natural gases form through bacterial and thermogenic conversion of organic matter over extended geological time. The isotopic properties of methane and C2+hydrocarbons are controlled by temperature dependent kinetic fractionation during maturation and mixing during migration and in reservoirs. Gas fields which are actively and repeatedly charged over extended periods of gas formation will receive compositionally and isotopically variable charges of natural gases that can mix in different proportions in single reservoirs. Episodic migration and multiple filling of reservoirs is a ubiquitous phenomenon observed in small and giant gas fields throughout the world. The following case histories from own research and from the literature will be discussed to illustrate this phenomenon: Gulf of Mexico: Pervasive mixing of bacterial and thermogenic gas charges results in large variations in isotopic signatures on a field and reservoir scale. Major formation and migration episodes are (1) Bacterial gases form in rapidly subsiding mini basins and migrate and accumulate around rising sell structures and active growth faults and (2) Following multiple charges of thermogenic gases mix in various proportions with bacterial gases. Angola: Giant oil fields off-shore Cabinda contain thermogenic gases with different isotopic signatures in the gas cap and the oil leg, indicating a multi phase migration of thermogenic; gases from mature to post-mature sources. The gas/oil columns are in some cases variable and suggest compartmentalization and/or unmixed oil hydrocarbon columns. Yacheng Gas Field: Gas composition and isotopic signatures of methane change from west to east in this giant field in the S. China Sea. Inert gas contents also vary vertically in the reservoir suggesting a late charge of a CO{sub 2} rich gas into the structure. South ltaly. Pliocene reservoirs in the Apulian Basin are mixtures of thermogenic and bacterial gases.

Schoell, M. [Chevron Petroleum Technology Co., La Habra, CA (United States); Beeunas, M.A. [Chevron USA, New Orleans, LA (United States)

1996-12-31

377

Structure, development and hydrocarbon potential of the Styrian Basin (Pannonian Basin system, Austria)  

Energy Technology Data Exchange (ETDEWEB)

The more then 4 km deep Neogene Styrian Basin represents an extensional structure on top of a crustal wedge, which was moving eastward during the final stages of the Alpine orogeny. Eastward extrusion was a consequence of continental escape and extensional collapse within the Eastern Alps. In a simple model, the evolution of the Styrian Basin can be subdivided into an Ottnangian to Karpatian synrift and a subsequent postrift phase. A Miocene (Karpatian to Early Badenian) magmatic phase is related to subduction along the Carpathian front or to the rise of lower crustal material underneath the Styrian Basin. Present-day high heat-flows are a consequence of the thinned crust beneath the Styrian Basin. Oil- and gas-prone sediments occur in the lower Miocene section. The elevated heat flow of the Miocene volcanic centres resulted in an early (Karpatian and Early Badenian) generation phase near the volcanoes. Because no traps were formed at that time, the generated hydrocarbons may have been lost. At some distance from the volcanoes, generation continued up to the Early Sarmatian. Hydrocarbons generated sine the Middle Badenian had a good chance of being trapped and forming accumulations. Only small amounts of oil formed after the Sarmatian. No commercial hydrocarbon deposits have been detected in the Styrian Basin to date. However, based on new gravimetric and seismic evaluations of the basin configuration, detailed source rock studies and numerical modelling of the thermal, hydrocarbon generation and migration histories, a good hydrocarbon potential is predicted for the Gnas Sub-basin and eventually for the southern Furstenfeld Sub-basin. (Author)

Sachsenhofer, R.F. [Mining Univ., Leoben (Austria). Inst. of Geological Sciences; Sperl, Hanns; Wagini, Alexander [Rohoel-Aufsuchungs AG, Vienna (Austria)

1996-12-31

378

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

Energy Technology Data Exchange (ETDEWEB)

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

Horstad, I.

1995-12-31

379

A method of separating hydrocarbons with a different degree of nonsaturation from hydrocarbon mixtures  

Energy Technology Data Exchange (ETDEWEB)

In the method of separating hydrocarbons with a different degree of nonsaturation from a hydrocarbon mixture by extractive distillation with a solvent or by a mixture of solvents, to lower loss of unsaturated hydrocarbons due to polymerization, to the solvent is added a polymerization inhibitor in the amount of 0.15-0.25%, on the basis of concentration of hydrocarbons with a maximum degree of nonsaturation, which amounts to 100-300 parts/million of solvent. Sodium nitrite, p-tert-butylcatechine, hydroquinone, p-benzoquinone, p-dinitrobenzene, 2-nitro-p-naphthol, o-nitrosonaphthol, and alpha-naphthoquinone are used as the inhibitor.

Anton, I.; Antonescu, I.; Bralner, A.; Cirlogan, C.; Goldes, D.

1980-11-28

380

Collision data involving hydro-carbon molecules  

International Nuclear Information System (INIS)

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

381

Recommended Critical Temperatures. Part I: Aliphatic Hydrocarbons  

Science.gov (United States)

This work deals with the critical temperature (Tc) for saturated and unsaturated aliphatic hydrocarbons. For 175 hydrocarbons (branched alkanes, branched and unbranched alkenes, and alkynes), an existing lack of critical temperature values have been complemented. Prediction methods have been used, the usefulness of which for specific groups and subgroups of the above mentioned hydrocarbons had been previously critically evaluated. The evaluation of accuracy of the relevant aspects of these methods is given in this study. An additional result of this work is the creation of a set of recommended experimental data on critical temperatures and normal boiling points for aliphatic hydrocarbons. Such a set has been created mainly for the purpose of evaluation of prediction methods applied in this study.

Owczarek, Iwona; Blazej, Krystyna

2003-12-01

382

Tritium dynamics within secondary contaminant sources in fractured shale bedrock  

International Nuclear Information System (INIS)

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

383

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

384

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1994-12-31

385

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2007-07-01

386

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

Science.gov (United States)

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

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

2014-05-01

387

Bacterial diversity in marine hydrocarbon seep sediments.  

Science.gov (United States)

Marine seeps introduce significant amounts of hydrocarbons into oceans and create unusual habitats for microfauna and -flora. In the vicinity of chronic seeps, microbes likely exert control on carbon quality entering the marine food chain and, in turn, hydrocarbons could influence microbial community composition and diversity. To determine the effects of seep oil on marine sediment bacterial communities, we collected sediment piston cores within an active marine hydrocarbon seep zone in the Coal Oil Point Seep Field, at a depth of 22 m in the Santa Barbara Channel, California. Cores were taken adjacent to an active seep vent in a hydrocarbon volcano, on the edge of the volcano, and at the periphery of the area of active seepage. Bacterial community profiles were determined by terminal restriction fragment length polymorphisms (TRFLPs) of 16S ribosomal genes that were polymerase chain reaction (PCR)-amplified with eubacterial primers. Sediment carbon content and C/N ratio increased with oil content. Terminal restriction fragment length polymorphisms suggested that bacterial communities varied both with depth into sediments and with oil concentration. Whereas the apparent abundance of several peaks correlated positively with hydrocarbon content, overall bacterial diversity and richness decreased with increasing sediment hydrocarbon content. Sequence analysis of a clone library generated from sediments collected at the periphery of the seep suggested that oil-sensitive species belong to the gamma Proteobacteria and Holophaga groups. These sequences were closely related to sequences previously recovered from uncontaminated marine sediments. Our results suggest that seep hydrocarbons exert a strong selective pressure on bacterial communities in marine sediments. This selective pressure could, in turn, control the effects of oil on other biota in the vicinity of marine hydrocarbon seeps. PMID:15250882

LaMontagne, Michael G; Leifer, Ira; Bergmann, Sandra; Van De Werfhorst, Laurie C; Holden, Patricia A

2004-08-01

388

Formation of hydrocarbons by bacteria and algae  

Energy Technology Data Exchange (ETDEWEB)

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

Tornabene, T.G.

1980-12-01

389

Biodegradation of Petroleum Hydrocarbons in Soil  

OpenAIRE

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

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

2003-01-01

390

Macroporous polymer foams by hydrocarbon templating  

OpenAIRE

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

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

2000-01-01

391

Hydrothermal hydrocarbon gases. 1, genesis and geothermometry  

OpenAIRE

Various sources for hydrothermal CH4 have been proposed over the years. While C isotope studies have narrowed the possibilities, enough higher hydrocarbon gas data now exist both to supplement the isotopic data and to permit additional deductions regarding origins. Comparison of typical C1–C6 data for gases of various origins (from sedimentary and crystalline rocks, and hydrothermal systems) reveals certain characteristics. Apart from isotopic differences, hydrothermal hydrocarbons differ f...

Darling, W. G.

1998-01-01

392

Job Migration: A Collaborative Effort  

Science.gov (United States)

Music teachers often change jobs several times during their careers. Reasons for job changes vary, but regardless, these changes bring a different set of challenges. Sharing knowledge and learning are part and parcel of collaboration. So what if, as education professionals, music teachers decided to collaborate during job migrations? For all music…

Wagoner, Cynthia L.

2012-01-01

393

Clocks, cryptochromes and Monarch migrations  

OpenAIRE

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.

Kyriacou, Charalambos P.

2009-01-01

394

Long migration flights of birds  

International Nuclear Information System (INIS)

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

395

Native vacancy migrations in zircon  

International Nuclear Information System (INIS)

Energy minimization methods were used to simulate the migration of Zr, Si, and O vacancies in zircon (ZrSiO4). Two sets of interatomic potentials were employed for comparison: one with O-Si-O three-body terms for the SiO4, and one without. Results for Si were inconclusive, but consistent with maintaining the integrity of the SiO4 molecular units. Both Zr and O vacancies can migrate on three-dimensional sublattice networks, thus supporting the experimentally observed diffusional isotropy. The predicted Zr vacancy migration energy (1.16-1.38 eV) was in good agreement with experiment if supplemented by Zr vacancy formation via Schottky or Frenkel defects (6.21-12.28 eV/defect). Oxygen vacancy migration energies were predicted to be 0.99-1.16 eV, somewhat lower than the experimental value of 4.64 eV measured in natural zircons, which thus may include significant contributions from vacancy formation mechanisms at 3.31-6.52 eV/defect. (orig.)

396

Tritium migration in tritiated anisole  

International Nuclear Information System (INIS)

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

397

Les questions de migrations internationales  

Science.gov (United States)

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

Samman, Mouna Liliane

1993-03-01

398

[The questions of international migration].  

Science.gov (United States)

International migrations have growing implications for both countries of destination. In the latter, the presence of foreigners and of members of their families today creates problems of integration, causes argument, and brings mounting xenophobia. Paralleling political, economic, and social measures taken by public authorities to respond to these difficulties, education needs to assist in diffusing the resulting social tensions by preparing the minds of learners and helping to develop new attitudes. In particular, when educational programs address questions of international migration, these should be treated in the framework of historical evolution in order that their real significance and their true temporal and spatial dimensions become apparent. It is also important that the growing interdependence between countries should be made plain, that national history should be placed in its international context, and that the true consequences of these developments should be made clear. In this context, learners need to be acquainted with Human Rights, thereby stressing universal moral values and the role of the individual. Lastly, questions relating to international migration are usually presented in the media in a selective and partial manner, and the young people who take in this information often accept the hasty judgments which are made of situations as proven facts. This is why all teaching about international migration needs to be considered or reconsidered in light of the complementary or competing actions of the media. (author's modified) PMID:12286405

Samman, M L

1993-03-01

399

THE SECONDARY EXTINCTION CORRECTION  

Energy Technology Data Exchange (ETDEWEB)

It is shown that Darwin's formula for the secondary extinction correction, which has been universally accepted and extensively used, contains an appreciable error in the x-ray diffraction case. The correct formula is derived. As a first order correction for secondary extinction, Darwin showed that one should use an effective absorption coefficient mu + gQ where an unpolarized incident beam is presumed. The new derivation shows that the effective absorption coefficient is mu + 2gQ(1 + cos/sup 4/2 theta )/(1 plus or minus cos/sup 2/2 theta )/s up 2/, which gives mu + gQ at theta =0 deg and theta = 90 deg , but mu + 2gQ at theta = 45 deg . Darwin's theory remains valid when applied to neutron diffraction. (auth)

Zachariasen, W.H.

1963-03-15

400

Polycyclic hydrocarbons - occurrence and determination  

International Nuclear Information System (INIS)

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

401

Hydrocarbon biodegradation in hypersaline environments.  

Science.gov (United States)

When mineral oil, hexadecane, and glutamate were added to natural samples of varying salinity (3.3 to 28.4%) from salt evaporation ponds and Great Salt Lake, Utah, rates of metabolism of these compounds decreased as salinity increased. Rate limitations did not appear to relate to low oxygen levels or to the availability of organic nutrients. Some oxidation of l-[U-C]glutamic acid occurred even at extreme salinities, whereas oxidation of [1-C]hexadecane was too low to be detected. Gas chromatographic examination of hexane-soluble components of tar samples from natural seeps at Rozel Point in Great Salt Lake demonstrated no evidence of biological oxidation of isoprenoid alkanes subject to degradation in normal environments. Some hexane-soluble components of the same tar were altered by incubation in a low-salinity enrichment culture inoculated with garden soil. Attempts to enrich for microorganisms in saline waters able to use mineral oil as a sole source of carbon and energy were successful below, but not above, about 20% salinity. This study strongly suggests a general reduction of metabolic rate at extreme salinities and raises doubt about the biodegradation of hydrocarbons in hypersaline environments. PMID:16345276

Ward, D M; Brock, T D

1978-02-01

402

PROTONATED POLYCYCLIC AROMATIC HYDROCARBONS REVISITED  

International Nuclear Information System (INIS)

We reconsider the contribution that singly protonated polycyclic aromatic hydrocarbons (PAHs; HPAH+s) might make to the Class A component of the 6.2 ?m interstellar emission feature in light of the recent experimental measurements of protonated naphthalene and coronene. Our calculations on the small HPAH+s have a band near 6.2 ?m, as found in experiment. While the larger HPAH+s still have emission near 6.2 ?m, the much larger intensity of the band near 6.3 ?m overwhelms the weaker band at 6.2 ?m, so that the 6.2 ?m band is barely visible. Since the large PAHs are more representative of those in the interstellar medium, our work suggests that large HPAH+s cannot be major contributors to the observed emission at 6.2 ?m (i.e., Class A species). Saturating large PAH cations with hydrogen atoms retains the 6.2 ?m Class A band position, but the rest of the spectrum is inconsistent with observed spectra.

403

SECONDARY AORTODUODENAL FISTULA  

Directory of Open Access Journals (Sweden)

Full Text Available "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 aortic reconstructive surgery, with the clinical presentation of upper gastrointestinal bleeding. On Immediate exploratory laparatomy, proximal part of abdominal Aorta was clamped. Duodonorrhaphy and aortic reconstruction with patch graft at the proximal suture line of aortic prosthesis was performed. Fortunately there was no pus, so tissue culture was not done. The intervention was concluded with an omentoplasty in order to protect the patch graft and to separate it from duodenorhaphy. Patient did well after the surgical management. Because of the increasing number of elective aortic aneurysm repairs in the aging population, it is likely that more patients with secondary aortoenteric fistula will present to the clinical physicians in the future. So, a high index of suspicion is necessary for prompt diagnosis and treatment of this actually life threatening event.

M. A. Mohammadzade

2007-07-01

404

Comparison of advanced seismic migration techniques using the CCSS2003 benchmark dataset  

Science.gov (United States)

The principal goal in reflection seismics is to obtain a high quality image of the structures in the subsurface. The main purpose in hydrocarbon exploration is to characterize the reservoir, whereas in deep seismic soundings it is e.g. to image fault zones at transform or convergent plate boundaries or even the crust-mantle boundary. Kirchhoff prestack depth migration (KPSDM) is widely considered as a state-of-the-art imaging technique to obtain a high quality image of the reflectivity distribution in the crust and mantle. In KPSDM the amplitudes of the reflected wavefield are smeared along the corresponding two-way traveltimes of the reflected wave, and constructive interference leads to an image of the reflector. Fresnel volume migration (FVM) uses the emergent angle at the receivers to propagate a ray back into the subsurface and restricts the migration operator to the Fresnel volume along this ray. Thus the migration is focused to that part of the reflector which is physically contributing to the reflection. This procedure reduces migration noise and enhances the image quality compared to KPSDM. Here, we compare both imaging algorithms for their application in deep seismic soundings using the CCSS2003 benchmark data set. This data set resembles a very heterogeneous crust with varying character of the crust-mantle (Moho) transition zone. Comparing the images of both algorithms along the Moho, Fresnel volume migration yields a significantly better resolution as well as less migration noise and enhances the contrast between the highly reflective lower crust and the underlying part of the upper mantle. This effect is particularly evident in areas where the Moho is not a first order discontinuity but rather a transition zone, which in turn allows a better distinction between the crust and the mantle in such areas.

Hlousek, Felix; Buske, Stefan

2013-04-01

405

Mediterranean Migrations: Regionalisms Versus Globalisation  

Directory of Open Access Journals (Sweden)

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

Martin Baldwin-Eduards

2004-06-01

406

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

Directory of Open Access Journals (Sweden)

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

J. Ben-Awuah

2014-03-01

407

Theoretical aspects of studying the migration processes  

OpenAIRE

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

Dilfuza Rasulova

2010-01-01

408

Theoretical aspects of studying the migration processes  

Directory of Open Access Journals (Sweden)

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

Dilfuza Rasulova

2010-02-01

409

Return migration: theory and empirical evidence  

OpenAIRE

In this paper we discuss forms of migration that are non-permanent. We focus on temporary migrations where the decision to return is taken by the immigrant. These migrations are likely to be frequent, and we provide some evidence for the UK. We then develop a simple model which rationalizes the decision of a migrant to return to his home country, despite a persistently higher wage in the host country. We consider three motives for a temporary migration: Differences in relative ...

Dustmann, C.; Weiss, Y.

2007-01-01

410

Risk-taking in unauthorised migration  

OpenAIRE

This thesis addresses the dynamics of high-risk unauthorised migration. First, it explores how new routes develop in relation to policies that seek to curtail unauthorised migration. Second, it analyses how aspiring migrants justify taking certain risks to migrate by negotiating risk information in relation to their life circumstances and considering the symbolic value of specific forms of migration. Finally and, in relation to the previous, the thesis discusses whether policies that seek to ...

Herna?ndez Carretero, Mari?a

2008-01-01

411

Extended Stolt F-K migration  

Energy Technology Data Exchange (ETDEWEB)

Despite their understanding that depth migration is a more powerful imaging tool than time migration, time migration still constitutes the majority of migration done today. In selecting a time-migration algorithm, three primary criteria are of concern: accuracy in imaging steep dips, accuracy in the presence of vertical velocity variation, and computational effort. The ideal algorithm would be efficient and unlimited in its ability to image steep dips in arbitrary vertical velocity structures. It would also accommodate gentle lateral velocity variations deemed acceptable for time-migration methods. A particularly attractive algorithm to consider is Stolt's f-k method: it is computationally efficient and has unlimited dip accuracy for constant-velocity media. Although Stolt's method can handle moderate vertical variations, errors become unacceptable for steep dips in the presence of large vertical velocity variation. An extension to Stolt migration removes its restrictions on vertical velocity variation, yielding accuracy comparable to phase-shift migration at only a fraction of the computational time. This extended Stolt method is based on partitioning the velocity field in a manner analogous to that in cascaded finite-difference migration and performing a number of stages of Stolt migrations. In each stage, the migration velocity field is closer to a constant - the ideal situation for Stolt migration - than when the migration is done conventionally (i.e., in just one stage). Empirical results and error analyses show that four stages of extended Stolt migration are sufficient to migrate steeply dipping events accurately in nearly any vertically varying velocity field. In fact, for a wide range of velocity fields and dips, as few as two stages will produce phase-shift quality images. The method can be used for two-dimensional, two-pass three-dimensional, and single-pass three-dimensional migrations.

Beasley, C.; Lynn, W.; Larner, K.; Nguyen, H.V.

1988-03-01

412

Vertical fluxes of aromatic and aliphatic hydrocarbons in the Northwestern Mediterranean Sea  

Energy Technology Data Exchange (ETDEWEB)

Aliphatic and aromatic hydrocarbon fluxes were measured in time series sediment trap samples at 200 m and at 1000 m depths in the open Northwestern Mediterranean Sea, from December 2000 to July 2002. Averaged fluxes of n-alkanes, UCM and T-PAH{sub 35} were 2.96 {+-} 2.60 {mu}g m{sup -2} d{sup -1}, 64 {+-} 60 {mu}g m{sup -2} d{sup -1} and 0.68 {+-} 0.59 {mu}g m{sup -2} d{sup -1}, respectively. Molecular compositions of both hydrocarbon classes showed a contamination in petrogenic hydrocarbons well above the background levels of such an open site, whereas pyrolytic hydrocarbons stand in the range of other open Mediterranean locations. Fluxes displayed ample interannual and seasonal variabilities, mainly related to mass flux variation while concentration evolutions trigger secondary changes in pollutant fluxes. High lithogenic flux events exported particles with a larger pollutant load than biogenic particles formed during the spring bloom and during the summer. Sinking hydrocarbons were efficiently transported from 200 m to 1000 m. - Highlights: > PAH composition, plots of diagnostic PAH ratios and the UCM abundance indicate that non aromatic and aromatic hydrocarbons in sinking particles in the Ligurian Sea were mainly of petrogenic origin. > Fluxes of T-PAH35, n-alkanes and UCM transported downward at 200 m during the year 2001 were 269, 1218 and 26 910 mg m{sup -2} yr{sup -1}, respectively. > Vertical fluxes of aliphatic and aromatic hydrocarbons displayed ample seasonal and inter-annual variabilities, mainly related to mass flux variation. Concentration variation triggered smaller changes in pollutant fluxes. > High fluxes of lithogenic particles occurring from early January to early March 2001 transported about 45% of the annual vertical export of contaminants. In April-May, high fluxes of biogenic particles also transported a significant fraction of pollutants, despite the dilution of petrogenic and pyrolytic PAHs by biogenic material. - Vertical fluxes of aliphatic and aromatic hydrocarbons in the Ligurian Sea show ample seasonal and inter-annual variability and are controlled by mass flux dynamics.

Deyme, Remi; Bouloubassi, Ioanna; Taphanel-Valt, Marie-Helene [Laboratoire d' Oceanographie et du Climat, Experimentation et Approches Numeriques (LOCEAN/IPSL), Universite Pierre et Marie Curie-CNRS-IRD-MNHN, UMR 7159, 4 Place Jussieu, 75252 Paris Cedex 05 (France); Miquel, Juan-Carlos [Environment Laboratories, International Atomic Energy Agency, 4 Quai Antoine 1er, MC98000 Monaco, Principality of Monaco (Monaco); Lorre, Anne [Laboratoire d' Oceanographie et du Climat, Experimentation et Approches Numeriques (LOCEAN/IPSL), Universite Pierre et Marie Curie-CNRS-IRD-MNHN, UMR 7159, 4 Place Jussieu, 75252 Paris Cedex 05 (France); Marty, Jean-Claude [CNRS- Universite Pierre et Marie Curie, UMR 7093, LOV, Observatoire oceanographique, 06234 Villefranche/mer (France); Mejanelle, Laurence, E-mail: laurence.mejanelle@upmc.fr [Laboratoire d' ECObiogeochimie Benthique, FRE3350, CNRS-Universite Pierre et Marie Curie, Avenue du Fontaule, 66650 Banyuls Sur Mer (France)

2011-12-15

413

Vertical fluxes of aromatic and aliphatic hydrocarbons in the Northwestern Mediterranean Sea  

International Nuclear Information System (INIS)

Aliphatic and aromatic hydrocarbon fluxes were measured in time series sediment trap samples at 200 m and at 1000 m depths in the open Northwestern Mediterranean Sea, from December 2000 to July 2002. Averaged fluxes of n-alkanes, UCM and T-PAH35 were 2.96 ± 2.60 ?g m-2 d-1, 64 ± 60 ?g m-2 d-1 and 0.68 ± 0.59 ?g m-2 d-1, respectively. Molecular compositions of both hydrocarbon classes showed a contamination in petrogenic hydrocarbons well above the background levels of such an open site, whereas pyrolytic hydrocarbons stand in the range of other open Mediterranean locations. Fluxes displayed ample interannual and seasonal variabilities, mainly related to mass flux variation while concentration evolutions trigger secondary changes in pollutant fluxes. High lithogenic flux events exported particles with a larger pollutant load than biogenic particles formed during the spring bloom and during the summer. Sinking hydrocarbons were efficiently transported from 200 m to 1000 m. - Highlights: ? PAH composition, plots of diagnostic PAH ratios and the UCM abundance indicate that non aromatic and aromatic hydrocarbons in sinking particles in the Ligurian Sea were mainly of petrogenic origin. ? Fluxes of T-PAH35, n-alkanes and UCM transported downward at 200 m during the year 2001 were 269, 1218 and 26 910 mg m-2 yr-1, respectively. ? Vertical fluxes of aliphatic and aroal fluxes of aliphatic and aromatic hydrocarbons displayed ample seasonal and inter-annual variabilities, mainly related to mass flux variation. Concentration variation triggered smaller changes in pollutant fluxes. ? High fluxes of lithogenic particles occurring from early January to early March 2001 transported about 45% of the annual vertical export of contaminants. In April-May, high fluxes of biogenic particles also transported a significant fraction of pollutants, despite the dilution of petrogenic and pyrolytic PAHs by biogenic material. - Vertical fluxes of aliphatic and aromatic hydrocarbons in the Ligurian Sea show ample seasonal and inter-annual variability and are controlled by mass flux dynamics.

414

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

International Nuclear Information System (INIS)

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

415

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

Science.gov (United States)

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

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

2014-01-01

416

The Psychology of Puerto Rican Migration.  

Science.gov (United States)

The psychology of the Puerto Rican migrant to the United States mainland is explored. Puerto Ricans have been migrating to the U.S. mainland and returning to Puerto Rico for more than 125 years, and, in fact, approximately 57% of all Puerto Ricans have migrated at one time or another. The migrant experience, including the circular migration…

Prewitt Diaz, Joseph O.

417

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

Science.gov (United States)

Electron beam induced dissociation (EBID) of residual hydrocarbons is a common contamination problem in electron microscopy. Formation of amorphous carbon thin films, dots, rings, and complex three-dimensional (3D) structures has been documented. In recent years there has been a renewed interest in utilization EBID of residual hydrocarbons for nanomanufacturing and metrology. With the increase and the diversification of EBID applications, ability for an a priori prediction of the appropriate deposition settings (such as electron beam current, diameter, and energy) that would result in a desired deposit size and geometry is becoming increasingly important. Toward this end, we report how simulations can be used to quantitatively predict the complex shape and non-linear dynamics of secondary ring-type microstructures formed around nanopillar deposits. The deposition experiments were performed on a Si(100) substrate for different electron beam energies and currents. Deposit shape and transient evolution were characterized using atomic force microscopy and critically compared against simulations results. PMID:18554805

Rykaczewski, Konrad; Marshall, Andrew; White, William B; Fedorov, Andrei G

2008-08-01

418

Chemistry of secondary organic aerosol formation  

Science.gov (United States)

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

Yee, Lindsay Diana

419

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

International Nuclear Information System (INIS)

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

420

Volatile hydrocarbons inhibit methanogenic crude oil degradation  

Directory of Open Access Journals (Sweden)

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

AngelaSherry

2014-04-01