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

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

Lehner F. K.

2006-11-01

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The pulsed migration of hydrocarbons across inactive faults  

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Full Text Available Geological fault zones are usually assumed to influence hydrocarbon migration either as high permeability zones which allow enhanced along- or across-fault flow or as barriers to the flow. An additional important migration process inducing along- or across-fault migration can be associated with dynamic pressure gradients. Such pressure gradients can be created by earthquake activity and are suggested here to allow migration along or across inactive faults which 'feel' the quake-related pressure changes; i.e. the migration barriers can be removed on inactive faults when activity takes place on an adjacent fault. In other words, a seal is viewed as a temporary retardation barrier which leaks when a fault related fluid pressure event enhances the buoyancy force and allows the entry pressure to be exceeded. This is in contrast to the usual model where a seal leaks because an increase in hydrocarbon column height raises the buoyancy force above the entry pressure of the fault rock. Under the new model hydrocarbons may migrate across the inactive fault zone for some time period during the earthquake cycle. Numerical models of this process are presented to demonstrate the impact of this mechanism and its role in filling traps bounded by sealed faults.

S. D. Harris

1999-01-01

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Carbon dioxide generation in Tugu Barat-C Field and role in hydrocarbon migration  

Energy Technology Data Exchange (ETDEWEB)

High carbon dioxide concentration has been discovered in the Tugu Barat (TGB) field. The wells drilled there infiltrate three hydrocarbon reservoirs, laid down in the Lower Miocene Baturaja Formation, the Middle Miocene Zone 14 and Zone 16 of the Upper Chibulakan Formation. The Baturaja Formation is composed of limestone intercalated with shale, while Zone 14 and Zone 16 are composed mainly of limestone. The purpose of this geochemical and petrophysical study was to determine the sources, the process and effects of carbon dioxide generation, and its migration and production rates. Results indicate that the carbon dioxide is generated by dissolution of limestone as the salinity of invaded meteoric water increases, a process that is very common within the limestone reservoir. During its generation, carbon dioxide creates overpressure that may induce secondary porosity which then acts as a pathway for hydrocarbon migration. 7 refs., 1 tab.,7 figs.

Prakasa, Y.; Hartanto, E.; Sulistyo, D. [Pertamina E and P Karangampel (Indonesia)

1998-12-31

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

Science.gov (United States)

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

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

2014-08-01

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

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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

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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

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Secondary cracking of C4 hydrocarbons from heavy oil catalytic pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

This study was conducted in response to the recent interest in the conversion of C4 hydrocarbons into ethene and propene. C4 hydrocarbons are significant intermediate products for catalytic pyrolysis of heavy oils. The produced C4 hydrocarbons can undergo secondary cracking reactions, yielding ethene, propene and other products. In order to better understand the reaction mechanism of heavy oil catalytic pyrolysis, this study examined the secondary cracking performance of C4 hydrocarbons from heavy oil catalytic pyrolysis, with particular focus on the influence of reaction temperature on feed conversion, product yields and liquid components. A confined fluidized bed reactor was used to examine the cracking behaviours on catalyst CEP-1 and quartz sand for C4 hydrocarbons from heavy oil catalytic pyrolysis. C4 hydrocarbons showed a good cracking ability on CEP-1. Butene was easier to convert than butane. Butane demonstrated a good cracking ability at high reaction temperatures only. On catalyst CEP-1, C4 hydrocarbons underwent cracking reactions, as well as reactions such as hydrogen transfer, polymerization and aromatization. The high conversion of C4 hydrocarbons thermal pyrolysis suggests that free radical reactions play an important role in the secondary cracking of C4 hydrocarbons. The product yields of C4 hydrocarbons pyrolysis on quartz sand were found to be lower than those on catalyst CEP-1. The selectivity of propene is higher than that of ethene for both catalytic pyrolysis and thermal pyrolysis of C4 hydrocarbons. 9 refs., 6 tabs., 6 figs.

Meng, X.; Xu, C.; Gao, J. [China Univ. of Petroleum, Changping, Beijing (China). State Key Laboratory of Heavy Oil Processing

2006-06-15

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

Energy Technology Data Exchange (ETDEWEB)

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

Magalhaes, Marcia Santos de Almeida

1999-07-01

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

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

M.P. Zakaria

2011-01-01

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An endogenous aryl hydrocarbon receptor ligand inhibits proliferation and migration of human ovarian cancer cells.  

Science.gov (United States)

The aryl hydrocarbon receptor (AhR), a ligand-activated transcription factor mediates many biological processes. Herein, we investigated if 2-(1'H-indole-3'-carbonyl)-thiazole-4-carboxylic acid methyl ester (ITE, an endogenous AhR ligand) regulated proliferation and migration of human ovarian cancer cells via AhR. We found that AhR was widely present in many histotypes of ovarian cancer tissues. ITE suppressed OVCAR-3 cell proliferation and SKOV-3 cell migration in vitro, which were blocked by AhR knockdown. ITE also suppressed OVCAR-3 cell growth in mice. These data suggest that the ITE might potentially be used for therapeutic intervention for at least a subset of human ovarian cancer. PMID:23851185

Wang, Kai; Li, Yan; Jiang, Yi-Zhou; Dai, Cai-Feng; Patankar, Manish S; Song, Jia-Sheng; Zheng, Jing

2013-10-28

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

Science.gov (United States)

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

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

1980-01-01

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

Science.gov (United States)

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

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

1990-01-01

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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

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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

15

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

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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.)

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

2014-01-01

18

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

Scientific Electronic Library Online (English)

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

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

19

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

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

Tissot B. P.

2006-11-01

20

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

 
 
 
 
21

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

Science.gov (United States)

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

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

22

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

23

Origin and migration of hydrocarbons in the Paleozoic system of Saudi Arabia  

Energy Technology Data Exchange (ETDEWEB)

This paper is a progress report on geochemical studies of the sub-Khuff Paleozoic rocks in Saudi Arabia, summarizing current laboratory results from both Saudi Aramco and American companies and their preliminary interpretations. From oil/oil and oil/rock correlations as well as maturity modeling, it may be concluded that sweet sub-Khuff oils, condensates, and gases are closely related to each other, and are derived from a common source: the hot shales of the basal Qusaiba Formation (Lower Silurian). The hydrocarbons that have been discovered in the Hawtah trend must have migrated updip from the presently overmature Rub-Al-Khali depocenter, where oil generation was initiated as early as 160 Ma. The oil window in the Rub-Al-Khali embayment, where active oil and condensate generation is taking place at present, is at depths between approximately 10,000 and 14,000 ft. Oil accumulation housed at depths more than approximately 14,000 {plus minus} 500 ft are being cracked into gas and condensate depending on variations in the generally low geothermal gradients of 1.5 {plus minus} 0.1F/100 ft. The residue of this natural refinery process is pyrobitumen, or deal oil, that is a pore plugging agent in many reservoirs at these depths. All products have very low-sulfur kerogen. The economic impact of these findings is very significant.

Franz, U.A. (Mobil Exploration and Producing Services, Dallas, TX (United States))

1991-08-01

24

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

International Nuclear Information System (INIS)

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

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

How do salt withdrawal minibasins form? Insights from forward modelling, and implications for hydrocarbon migration  

Science.gov (United States)

Existing models for the initiation of salt withdrawal minibasins focus on the role of triggers that exist within the minibasin, either stratigraphic (e.g. differential deposition) or tectonic (extension, translation or contraction). Existing studies tend to focus on complex settings, such as continental margins, which contain many different potential triggering mechanisms. It can be difficult in these settings to identify which process is responsible for minibasin initiation, or the influence of individual factors on their subsequent development. Salt withdrawal minibasins also exist in simpler settings, without any obvious intrinsic trigger; the region of the North German Basin used by Trusheim (1960) in the classic definition of salt withdrawal geometries was of this nature. There is no overall basal or surface slope, no major lateral movement, and there is no depositional heterogeneity. Previously recognized trigger processes for minibasin initiation do not apply in this benign setting, suggesting that other, potentially more fundamental, influences may be at work. A simple forward-modelling approach shows how, in the absence of any other mechanism, a new minibasin can develop as the consequence of salt movement driven by its neighbour, and families of withdrawal minibasins can propagate across a region from a single seed point. This new mechanism may explain how some minibasins appear to initiate before the sediment density has exceeded that of the underlying salt. The forward modelling also indicates that some minibasins begin to invert to form turtle anticlines before the underlying salt has been evacuated, so that the timing of turtle formation may not be diagnostic of weld formation. This mechanism may also give rise to salt-cored turtles that have a lens of salt trapped beneath their cores. These new findings have implications for hydrocarbon migration and trapping.

Peel, Frank J.

2014-09-01

27

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2008-06-15

28

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

Science.gov (United States)

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

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

2009-10-15

29

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

30

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

2006-01-01

31

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

Science.gov (United States)

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

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

2014-08-01

32

Unraveling secondary migration effects through the regional evaluation of PVT data: a case study from Quadrant 25, NOCS  

Energy Technology Data Exchange (ETDEWEB)

PVT data offer a unique source of information for the characterization of hydrocarbon migration from a petroleum exploration point of view. A case study is presented here in which a large fluid compositional variability encountered in the northern half of Quadrant 25, Norwegian North Sea, and especially the enigmatic occurrence of an undersaturated light oil in a shallow Jurassic reservoir in well 25/6-1, are explained using PVT data. Recognition and numerical simulation of the effects of phase separation allowed the characterization of genetic fluid relationships and regional migration trends. Sequential flash calculations indicated the most likely formation mechanism for the 25/6-1 fluid, which is by condensation out of a migrating saturated gas phase. The volumetrics involved in this process indicate that the gas phase predominated, with only 3 vol.% of the original fluid ending up as a liquid. (author)

Primio, R. di [Norsk Hydro Exploration and Production, Bergen (Germany)

2002-06-01

33

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

Energy Technology Data Exchange (ETDEWEB)

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

Catherine L. Hanks

2008-12-31

34

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 < C?? mineral 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

35

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

Energy Technology Data Exchange (ETDEWEB)

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

Larter, S.; Bowler, B.; Bennett, B. [University of Newcastle (United Kingdom). Fossil Fuels and Environmental Geochemistry; Clarke, E.; Wilson, C.; Moffatt, B. [BG International, Reading (United Kingdom); Yardley, G.; Carruthers, D. [Heriot-Watt Univ., Edinburgh (United Kingdom). Dept. of Petroleum Engineering

2000-07-01

36

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

Directory of Open Access Journals (Sweden)

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

Larter Steve

2000-10-01

37

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

Directory of Open Access Journals (Sweden)

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

Chenet P. Y.

2006-11-01

38

A study of hydrocarbon migration events: Development and application of new methods for constraining the time of migration and an assessment of rock-fluid interactions. Final report, September 1, 1991--August 31, 1994  

Energy Technology Data Exchange (ETDEWEB)

The authors are conducting the research to test and refine a paleomagnetic method for dating hydrocarbon migration, and to assess the chemical alteration of crude oils resulting from fluid-rock interactions. Samples were collected for paleomagnetic and organic geochemical investigations from several units. These include the Old Red Sandstone in Scotland, and the Schoolhouse Member of the Maroon Formation and the Belden Formation in Colorado. Studies of these units are completed or underway. In addition, simulation experiments, where the authors are attempting to form magnetite in the laboratory, are underway.

Elmore, R.D.; Engel, M.H.

1993-12-31

39

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

40

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

Science.gov (United States)

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

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

2014-01-01

 
 
 
 
41

Secondary Organic Aerosol Formation and Organic Nitrate Yield from NO3 Oxidation of Biogenic Hydrocarbons.  

Science.gov (United States)

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

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

2014-10-21

42

Assessing the influence of secondary organic versus primary carbonaceous aerosols on long-range atmospheric polycyclic aromatic hydrocarbon transport.  

Science.gov (United States)

We use the chemical transport model GEOS-Chem to evaluate the hypothesis that atmospheric polycyclic aromatic hydrocarbons (PAHs) are trapped in secondary organic aerosol (SOA) as it forms. We test the ability of three different partitioning configurations within the model to reproduce observed total concentrations in the midlatitudes and the Arctic as well as midlatitude gas-particle phase distributions. The configurations tested are (1) the GEOS-Chem default configuration, which uses instantaneous equilibrium partitioning to divide PAHs among the gas phase, a primary organic matter (OM) phase (absorptive), and a black carbon (BC) phase (adsorptive), (2) an SOA configuration in which PAHs are trapped in SOA when emitted and slowly evaporate from SOA thereafter, and (3) a configuration in which PAHs are trapped in primary OM/BC upon emission and subsequently slowly evaporate. We also test the influence of changing the fraction of PAHs available for particle-phase oxidation. Trapping PAHs in SOA particles upon formation and protecting against particle-phase oxidation (2) better simulates observed remote concentrations compared to our default configuration (1). However, simulating adsorptive partitioning to BC is required to reproduce the magnitude and seasonal pattern of gas-particle phase distributions. Thus, the last configuration (3) results in the best agreement between observed and simulated concentration/phase distribution data. The importance of BC rather than SOA to PAH transport is consistent with strong observational evidence that PAHs and BC are coemitted. PMID:24564497

Friedman, C L; Pierce, J R; Selin, N E

2014-03-18

43

Fluids in the Palaeogene Formation of Gaoyou Sag in the Southern Part of North Jiangsu Basin, China: Evidence for Hydrocarbon Migration and Accumulation  

Science.gov (United States)

Gaoyou Sag, lying in the middle of the Dongtai Depression in the North Jiangsu basin, China, has a well developed fault system and is characterised by structurally complicated oil and gas fields. Its oil-water relationship is very complicated. In the present study, we present the distribution of formation water chemistry, crude oil density, formation pressures and fluid potential in the Palaeogene formation of the Gaoyou Sag . The purpose of this article is to: (1) analyse the cause of hydrochemical diversity; (2) identify the flow pattern and evolution; and (3) understand the interplay between the flow of formation water and hydrocarbon migration and accumulation. The results showed that large variances in formation water chemistry occur in different oilfields of the Gaoyou Sag (Figure 1) due to dilution by meteoric water recharge, concentration by membrane filtration and complexity of geological structure. The low salinity (mean values from 8.53 g/L to 9.67 g/L) of the formation water and heavy crude oil density (up to 0.94g/cm3) in the Xuchuang oilfield indicate influence from meteoric water infiltration; the deep depression areas are mainly of connate origin. Geofluids in the Xuchuang, Zhenwu and Yang'an oilfields mainly flow vertically through the Zhenwu and Hanliu faults, while geofluids in the Shanian oilfield mainly migrate laterally through the reservoirs and are adjusted vertically along some cutting faults. Palaeo-hydrodynamic evolution had an affinity with the generation, migration, accumulation and preservation of hydrocarbons. In the depositional stages of the Dainan and Sanduo formations, formation water was expelled outward and upward from lacustrine mudstones of the deep depression into shallow sands of nearby oilfields, driven by compaction and overpressure. Hydrocarbon migrated with formation water and gathered in appropriate traps, forming primary reservoirs. During the Zhenwu and Sanduo movements, there were tectonic uplifts and the strata suffered denudation. Meteoric water infiltrated inward and downward along active faults and denudated strata, meaning the original oil and gas pools suffered oxidation, damage and even loss. Figure 1 Vertical distribution of total dissolved solids (TDS) of formation water in the Xuchuang, Zhenwu, Yang'an and Shanian oilfields. (A) Location of those four oilfields in the N-S cross section shown in Figure 1; (B) TDS values of those four oilfields vary differently with burial depth.

LI, M.; Lou, Z.; Zhu, R.; Jin, A.

2013-12-01

44

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1990-11-01

45

Distribution of some hydrocarbons in ambient air near Delft and the influence on the formation of secondary air pollutants.  

Science.gov (United States)

The relative concentrations of hydrocarbons in the atmosphere may provide information concerning their origin. It appears that the hydrocarbon composition measured in Delft (The Netherlands) is entirely different for northern and southern wind directions. This points to different sources. The most important sources for this area are natural gas leaks, traffic, and (petrochemical) industries. It appears that the relative potential of the precursor mix to form peroxyacetylnitrate (PAN) and ozone is also different for both wind directions. PMID:68543

Bos, R; Guicherit, R; Hoogeveen, A

1977-05-01

46

Distribution of some hydrocarbons in ambient air near Delft and the influence on the formation of secondary air pollutants  

Energy Technology Data Exchange (ETDEWEB)

The relative concentrations of hydrocarbons in the atmosphere may provide information concerning their origin. It appears that the hydrocarbon composition measured in Delft (The Netherlands) is entirely different for northern and southern wind directions. This points to different sources. The most important sources for this area are natural gas leaks, traffic, and (petrochemical) industries. It appears that the relative potential of the precursor mix to form peroxyacetylnitrate (PAN) and ozone is also different for both wind directions.

Bos, R.; Guicherit, R.; Hoogeveen, A.

1977-05-01

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

Expression of the aryl hydrocarbon receptor is not required for the proliferation, migration, invasion, or estrogen-dependent tumorigenesis of MCF-7 breast cancer cells.  

Science.gov (United States)

The AhR was initially identified as a ligand-activated transcription factor mediating effects of chlorinated dioxins and polycyclic aromatic hydrocarbons on cytochrome P450 1 (CYP1) expression. Recently, evidence supporting involvement of the AhR in cell-cycle regulation and tumorigenesis has been presented. To further define the roles of the AhR in cancer, we investigated the effects of AhR expression on cell proliferation, migration, invasion, and tumorigenesis of MCF-7 human breast cancer cells. In these studies, the properties of MCF-7 cells were compared with those of two MCF-7-derived sublines: AH(R100) , which express minimal AhR, and AhR(exp) , which overexpress AhR. Quantitative PCR, Western immunoblots, 17?-estradiol (E2 ) metabolism assays, and ethoxyresorufin O-deethylase assays showed the lack of AhR expression and AhR-regulated CYP1 expression in AH(R100) cells, and enhanced AhR and CYP1 expression in AhR(exp) cells. In the presence of 1?nM E2 , rates of cell proliferation of the three cell lines showed an inverse correlation with the levels of AhR mRNA. In comparison with MCF-7 and AhR(exp) cells, AH(R100) cells produced more colonies in soft agar and showed enhanced migration and invasion in chamber assays with E2 as the chemoattractant. Despite the lack of significant AhR expression, AH(R100) cells retained the ability to form tumors in severe combined immunodeficient mice when supplemented with E2 , producing mean tumor volumes comparable to those observed with MCF-7 cells. These studies indicate that, while CYP1 expression and inducibility are highly dependent on AhR expression, the proliferation, invasion, migration, anchorage-independent growth, and estrogen-stimulated tumor formation of MCF-7 cells do not require the AhR. PMID:22388733

Spink, Barbara C; Bennett, James A; Lostritto, Nicole; Cole, Jacquelyn R; Spink, David C

2013-07-01

49

Secondary effects of catalytic diesel particulate filters: reduced aryl hydrocarbon receptor-mediated activity of the exhaust.  

Science.gov (United States)

Diesel exhaust contains numerous toxic substances that show different modes of action such as triggering aryl hydrocarbon receptor (AhR)-mediated pathways. We investigated AhR-mediated activity of exhaust generated by a heavy-duty diesel engine operated with or without iron- or copper/iron-catalyzed diesel particulate filters (DPFs). AhR agonists were quantified using the DR-CALUX reporter gene assay (exposure of cells for 24 h). We found 54-60 ng 2,3,7,8-tetrachlorodibenzo-p-dioxin CALUX equivalents (TCDD-CEQs) per m3 of exhaust in unfiltered samples and 6-16 ng TCDD-CEQ m3 in DPF-treated samples. DPF applications decreased TCDD-CEQ concentrations by almost 90%. Concentrations of known AhR agonists were determined with GC/HRMS and converted to TCDD-CEQ concentrations using compound-specific relative potency values. The analyzed nine polycyclic aromatic hydrocarbons (PAHs) and the 172,3,7,8-chlorinated dibenzodioxins/furans (23,7,8-PCDD/Fs) contributed only marginally (0.6-1.6%) to the total agonist concentration. However, both DPFs also decreased concentrations of individual PAHs by 7(0-80%. Variation of the assay exposure time (8, 24, 48,72, and 96 h) revealed that AhR-mediated activity decreased over time and reached a plateau after 72 h, which was most likely due to biotransformation of AhR agonists by the exposed H4IIE cells. At the plateau, we measured 1-2 ng TCDD-CEQ m(-3) in both an unfiltered and a filtered exhaust sample. Our findings show that DPFs are a promising technology to detoxify diesel exhaust regarding compounds with AhR-mediated activity. PMID:18497156

Wenger, Daniela; Gerecke, Andreas C; Heeb, Norbert V; Zennegg, Markus; Kohler, Martin; Naegeli, Hanspeter; Zenobi, Renato

2008-04-15

50

Instantaneous secondary organic aerosol yields and their comparison with overall aerosol yields for aromatic and biogenic hydrocarbons  

Science.gov (United States)

An instantaneous secondary organic aerosol yield (IAY) is a different quantity than an overall aerosol yield (OAY), both qualitatively and quantitatively. Starting from Odum's OAY equation, this paper derives and presents a new equation for the calculation of IAY values. As examples, the two-product form of the equation is applied to 10 representative aromatic and biogenic reactive organic gas (ROG) experiments in the literature. Values of IAY and OAY corresponding to wide ranges of organic aerosol mass concentrations ( M0) are calculated using the new IAY equation in this paper and the original Odum's OAY equation. These IAY and OAY values are shown through aerosol yield curves, which are the plots of IAY or OAY versus M0. Comparative analysis of the IAY and OAY curves shows that both IAY and OAY increase monotonically with M0 and they approach a common maximum value when M0 becomes very high. However, when M0 approaches zero, OAY also approaches zero but IAY approaches a fixed positive value for a given ROG. At any given M0 value, the value of IAY is always higher than that of OAY. The relative differences between IAY and OAY are especially significant under typical ambient and experimental M0 levels. IAY values can be orders of magnitude higher than OAY values and are much better representations of aerosol yields under these M0 levels. When it is used for secondary organic aerosols (SOA) estimation and modelling, the new IAY equation will significantly improve the underestimation of SOA formation caused by directly using the original OAY equation. More sophisticated SOA algorithms could also be developed based on the IAY equation presented here.

Jiang, Weimin

51

Secondary organic aerosol formation from xylenes and mixtures of toluene and xylenes in an atmospheric urban hydrocarbon mixture: Water and particle seed effects (II)  

Science.gov (United States)

Secondary organic aerosol (SOA) formation from the photooxidation of o-, p-xylene, and toluene with xylene mixtures was investigated in the UNC dual outdoor smog chambers. Experiments were performed with different initial background aerosol concentrations and levels of relative humidity (RH) in the environment of an eleven component mixture of non-SOA-forming dilute urban hydrocarbon mixture, oxides of nitrogen and sunlight. Post-nucleation was observed in most of the experiments in the 14-20 nm range except under the conditions with high background aerosol (>5 ?g m -3) and with low o-xylene concentrations (p-Xylene had a lower SOA yield compared with o-xylene and the yields in experiments with toluene and xylene mixtures ranged from 1.1% to 10.3%. SOA yield was found to be positively correlated with the particle water (H 2Op) content. A new condensed aromatic kinetic mechanism employing uptake of organics in H 2Op as a key parameter was applied to all the experiments and the simulations showed reasonable fits to the observed data.

Zhou, Yang; Zhang, Haofei; Parikh, Harshal M.; Chen, Eric H.; Rattanavaraha, Weruka; Rosen, Elias P.; Wang, Wenxing; Kamens, Richard M.

2011-07-01

52

Features of distribution of scattered organic matter in clay masses of different thickness and their link to primary migration of hydrocarbons  

Energy Technology Data Exchange (ETDEWEB)

New data are presented on the features of spatial distribution of individual components of scattered organic matter in clay beds of different thickness. The chromatographic model of migration of scattered organic matter from clays by analogy with migration of bitumoids from clays is confirmed.

Matusevich, V.M.; Chistyakova, N.F.

1982-01-01

53

Ventricular proliferation zones in the brain of an adult teleost fish and their relation to neuromeres and migration (secondary matrix) zones.  

Science.gov (United States)

Zones containing actively dividing cells (proliferation zones: PZs), in the brain of adult three-spined sticklebacks, were identified by autoradiographic detection of (3)H-thymidine and immunocytochemical detection of the thymidine analogue 5'-bromodeoxyuridine (BrdU), singly or in combination, and by immunocytochemical detection of proliferating cell nuclear antigen (PCNA) by monoclonal antibodies. The PZs are associated with boundaries between adult brain regions, as well as with defined morphofunctional subdivisions. PZs are located at the border between the telencephalon and diencephalon, and at the border between the mesencephalon and the rhombencephalon. In the midbrain, the PZ follows the dorsomedial, caudal, and ventrolateral aspects of each tectal hemisphere, extending over the caudal aspect of the torus semicircularis to the nucleus lateralis valvulae. In the hindbrain, the major PZ apparently represents the persisting embryonic secondary matrix layer of the developing cerebellum. In the forebrain, the PZs are associated with the ventricular zones of the olfactory bulbs and ventral telencephalic area ("subpallium"), dorsal telencephalic area ("pallium"), preoptic region, ventral thalamus, dorsal thalamus, epithalamus, pretectum, posterior tuberculum, and the hypothalamus. The diencephalic PZs are parcellated according to a neuromeric organisation (a synencephalic, a posterior, and an anterior parencephalic neuromere: p1, p2, and p3). The PZs of the secondary prosencephalon (telencephalon and hypothalamus) thus would belong to neuromeres p4-6, but do not form an immediately recognised serial pattern. The prosencephalic PZs correlate well with parts of embryonic migration areas as defined by Bergquist and Källén ([1954] J. Comp. Neurol. 100:627-659), morphogenetic fields from which postmitotic neurones migrate to their final destination. PMID:11413549

Ekström, P; Johnsson, C M; Ohlin, L M

2001-07-16

54

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2005-02-01

55

Air-Xe enrichments in Elk Hills oil field gases: role of water in migration and storage  

Science.gov (United States)

Hydrocarbons from the Elk Hills Naval Petroleum Reserve (NPR#1), Bakersfield, CA, are enriched in heavy noble gases. The 132Xe/ 36Ar ratios are as high as ˜576 times the ratio in air and represent the largest relative Xe-enrichments ever observed in terrestrial fluids. The Xe isotopic composition is indistinguishable from air. We show that these samples cannot be explained by equilibration of oil with air saturated water and secondary enrichment via a Rayleigh distillation gas stripping process. Based on laboratory studies of others with potential petroleum source rocks, we believe the source of this enriched heavy noble gas component was adsorbed air initially trapped in/on the source rocks that was expelled and mixed with the hydrocarbons during expulsion and primary migration. Kr and Xe enrichments decrease with increasing 36Ar concentration. We propose a model in which an initial Kr-Xe-enriched hydrocarbon becomes diluted with noble gases extracted from air saturated groundwater during expulsion, migration, and storage. The model generates an integrated water/hydrocarbon ratio for the production fluid which indicates a minimal role for water in hydrocarbon expulsion and migration. The results are interpreted to provide time/geometrical constraints on the mechanisms by which hydrocarbons can migrate as a separate phase.

Torgersen, T.; Kennedy, B. M.

1999-04-01

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  

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

57

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.

58

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

59

Post mortem simulation study of hydrocarbon generation and migration on the inverted south-western rim of the North German Basin - 2D basin modelling study  

Energy Technology Data Exchange (ETDEWEB)

In the past a wide range of extensive research studies was undertaken with the aim of identifying a number of potential play types and concepts like the Rotliegend Fair Way for example. Based on this, the aim of the study was to undertake a post-mortem simulation in order to reassess the established concepts and accepted ideas as well as to identify the limitation of the modelling tool. The primary goal was to provide a valuable contribution to understanding of hydrocarbon and nitrogen evolution in a close association with the structural evolution of the North German basin and in particular with reference to the Coniacian-Santonian inversion. (orig.)

Kus, J.; Cramer, B.; Gerling, P. [Bundesanstalt fuer Geowissenschaften und Rohstoffe, Hannover (Germany); Bueker, C. [RWTH Aachen (Germany). Inst. fuer Geologie und Geochemie des Erdoels und der Kohle; Kockel, F. [Eiermarkt, Burgwedel (Germany)

2001-07-01

60

Synergetic catalysis in hydrocarbon generation  

Energy Technology Data Exchange (ETDEWEB)

Thermogenesis as the sole origin of hydrocarbons has been questioned by Gulf Coast petroleum geologists for two reasons: (1) lack of thermally mature source beds except on the basin`s Mesozoic rim and (2) persuasive empirical evidence of shallow, early migration and emplacement. Enigmatically, even subsequent deeper burial of the reservoirs has not resulted in thermal maturity. However, recent laboratory research has identified several natural catalysts that significantly lower temperatures needed for conversion of organic materials into hydrocarbons. Perhaps synergism among these or as yet undiscovered catalysts, together with geologic reaction times, is capable of producing hydrocarbons at temperatures low enough for early emplacement.

Sabate, R.W. [San`Doil Exploration L.C., New Orleans, LA (United States); Baker, C.C. [NAC of FINDING, Slidell, LA (United States)

1994-09-01

 
 
 
 
61

Synergetic catalysis in hydrocarbon generation  

Energy Technology Data Exchange (ETDEWEB)

Thermogenesis as the sole origin of hydrocarbons has been questioned by Gulf Coast geologists for two reasons: (1) lack of thermally mature source beds except on the basin`s Mesozoic rim and (2) persuasive empirical evidence of shallow, early generation, migration, and emplacement. Enigmatically, even subsequent deeper burial of the reservoirs has not resulted in thermal maturity. However, recent laboratory research has identified several natural catalysts that significantly lower temperatures needed for conversion of organic materials into hydrocarbons. Perhaps synergism among these or as-yet-undiscovered catalysts, together with geologic reaction times, is capable of producing hydrocarbons at temperatures low enough for early emplacement.

Sabate, R.W. [San`Doil Exploration L.C., New Orleans, LA (United States); Baker, C.C. [Consulting Petroleum Geologist, Metairie, LA (United States)

1994-12-31

62

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

63

Carbonate redistribution, element mobilisation and petroleum hydrocarbon migration in Posidonia shale (Hils basin, NW Germany) as a function of palaeotemperature load from the Vlotho mass; Karbonatumverteilung, Mobilisation von Elementen und Migration von Erdoel-Kohlenwasserstoffen im Posidonienschiefer (Hilsmulde, NW-Deutschland) in Abhaengigkeit von der Palaeotemperaturbeanspruchung durch das Massiv von Vlotho  

Energy Technology Data Exchange (ETDEWEB)

Temperature-controlled processes of carbonate redistribution, element mobilisation and petroleum hydrocarbon migration in the Posidonia shale of North West Germany (Lower Toarcian) were documented, and a statistical evaluation was made. The investigations focused on six Posidonia shales of the Hils basin which had been exposed to increasing palaeotemperature stress from SE to NW in the direction of the injected mass of Vlotho. According to earlier investigations, the mean values of vitrinite reflection in the six boreholes are between 0.48% Rm and 1.45% Rm. This corresponds to a maximum palaeotemperature of 93-190 C. (orig./EF) [Deutsch] Im Rahmen der vorliegenden Arbeit wurden temperaturgesteuerte Prozesse der Umverteilung von Karbonaten, der Mobilisation von Elementen und der Migration von Erdoel-Kohlenwasserstoffen im nordwestdeutschen Posidonienschiefer (Unteres Toarcium) dokumentiert und bilanziert. Gegenstand der Untersuchungen waren sechs Posidonienschieferprofile aus dem Bereich der Hilsmulde, die von SE and NW in Annaeherung an das Intrusivmassiv von Vlotho eine zunehmende Palaeotemperaturbeanspruchung erfahren haben. Frueheren Untersuchungen zufolge liegen die Mittelwerte der Vitrinitreflexion in den sechs Bohrungen zwischen 0,48% Rm und 1,45% Rm, was einem Bereich der maximal erreichten Palaeotemperatur zwischen ca. 93 C und ca. 190 C entspricht. (orig./EF)

Jochum, J.

1993-04-01

64

Detection and identification of side reactions of halogenated hydrocarbon solvents with amines of pharmaceutical interest by secondary processes to the neutralizations of sulphonphthaleinic dyes with these amines.  

Science.gov (United States)

The neutralization reactions between amines and diprotic acid dyes in organic solvents generate (dye-, amineH+) and [dye2-, (amineH+)2] ion associates that show two absorption bands in the visible spectrum. An unidentified third absorption band; which appears with a high amine concentration, proves that halogenated hydrocarbon solvents (dichloromethane, chloroform, 1,2-dichloroethane, and carbon tetrachloride) give side reactions with amines (atropine, tropine, quinine, ephedrine, and ajmaline) that generate a quaternary ammonium salt, N-halogenalkylammonium halide ([N(+)-RX,X-]). The molecular weight of the quaternary ammonium salt is the sum of the amine and that of the solvent. The (N(+)-RX,X-) ion associated reacts with [dye2-, (amineH+)2] by substitution reactions, forming (dye2-, amineH+, N(+)-RX) and (dye2-, (N(+)-RX)2] ion associates that justify the third absorption band. The amine-solvent side reactions are of first order with respect to the amine, being very slow processes with rate constant values from 399.4 h-1 (tropine-dichloromethane reaction) to 15.8 h-1 (atropine-1,2- dichloroethane reaction). Rate constants increase with the basicity of the amine measured in the halogenated hydrocarbons employed. Rate constants also increase with a reduction in the number of the halogen atoms present in the halogenated solvent. The new visible absorption band that appears in the amine-dye neutralization gives a quick colorimetric test to bring to light this kind of side reaction in these solvents. PMID:8169795

Hernandez Gainza, A; Konyeaso, R I; Asenjo, R A

1994-02-01

65

Hydrocarbon Transport  

Science.gov (United States)

... in cold regions. The informa- tion gained through this research is applicable in cold regions ... pads' placed on the surface of the soil. Slug inputs of various contaminants, including hydrocarbons ...

66

Planet Migration  

CERN Document Server

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 are lower. There are major uncertainties in migration rates due to a lack of knowledge about the detailed physical properties of disks. We also describe some additional forms of migration.

Lubow, Stephen H

2010-01-01

67

Planet Migration  

Science.gov (United States)

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 are lower. There are major uncertainties in migration rates due to a lack of knowledge about the detailed physical properties of disks. We also describe some additional forms of migration.

Lubow, S. H.; Ida, S.

68

Planet Migration  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Lubow, Stephen H.; Ida, Shigeru

2010-01-01

69

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

70

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

71

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 SciELO Spain | Language: Spanish Abstract in spanish 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.

72

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.

73

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

74

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.

75

Medical migration.  

Science.gov (United States)

The issue of professional migration, however emotional it may have become, ought not to be regarded in moralizing terms. The history of western medicine is the history of migrating physicians. A doctor who moves from a locality to another to take up a new assignment there cannot be said to have "abandoned his patients". This emotional bond has become the victim of specialization and of depersonalization of medical services and not of medical migration, brain drain or otherwise. The primary reason for medical migration is not financial; the desire to migrate usually begins with the desire to learn. Professionals crave in the first line for professional satisfaction. The migration of medical manpower cannot be stopped with administrative measures and will not be stopped by exhortations and appeals, moralization and condemnations. Brain drain is a global phenomenon and has always been so. A country which loses its professionals, its doctors, should examine the social relationships within the profession and should investigate whether the opportunities for deriving professional satisfaction from everyday work exist or whether these have been thwarted by the hierarchy, conservatism, cronyism and the general lack of comprehension of what good medical care is about. PMID:11593497

Loefler, I J

2001-10-01

76

THERMAL PROPERTIES OF SECONDARY ORGANIC AEROSOLS  

Science.gov (United States)

Volume concentrations of steady-state secondary organic aerosol (SOA) were measured in several hydrocarbon/NOx irradiation experiments. These measurements were used to estimate the thermal behavior of the particles that may be formed in the atmosphere. These laborator...

77

Hydrocarbon habitat of the west Netherlands basin  

Energy Technology Data Exchange (ETDEWEB)

The complex West Netherlands Basin contains oil and gas in Triassic and Upper Jurassic to Cretaceous clastic reservoir sequences. The understanding has always been that the Carboniferous coal measures have generated only gas and the Jurassic marine Posidonia Shale only oil. However, detailed geochemical analyses show that both source rocks have generated oil and gas. Geochemical fingerprinting established a correlation of the hydrocarbons with the main source rocks. The occurrence of these different hydrocarbons is consistent with migration routes. Map-based charge modeling shows that the main phase of hydrocarbon generation occurred prior to the Late Cretaceous inversion of the West Netherlands Basin. However, along the southwest flank of the basin and in lows between the inversion highs, significant charge continued during the Tertiary. Biodegradation of oils in Jurassic and Cretaceous reservoirs occurred during the earliest Tertiary, but only in reservoirs that were at that time at temperatures of less then 70 to 80[degrees]C, where bacteria could survive. This study shows that also in a mature hydrocarbon province an integrated hydrocarbon habitat study with modern analyses and state-of-the-art technology can lead to a much improved understanding of the distribution of oil and gas in the subsurface. The results of this study will allow a better risk assessment for remaining prospects, and an improved prediction of the type of trapped hydrocarbons in terms of gas, oil, and biodegraded oil.

De Jager, J. (Nederlandse Aardolie Maatschappij, Assen (Netherlands)); Doyle, M. (Petroleum Development Oman, Muscat (Oman)); Grantham, P. (KSEPL/Shell Research, Rijswijk (Netherlands)); Mabillard, J. (Shell Nigeria, Port Harcourt (Nigeria))

1993-09-01

78

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

79

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

80

Additional insights into luminescence process of polycyclic aromatic hydrocarbons with carbonyl groups: photophysical properties of secondary N-alkyl and tertiary n,n-dialkyl carboxamides of naphthalene, anthracene, and pyrene.  

Science.gov (United States)

Here we report the substitution effects of N-alkyl and N,N-dialkyl carboxamide groups on the fluorescence properties of polycyclic aromatic hydrocarbon chromophores, so as to control their fluorescence properties. The fluorescence properties of compounds obtained using solvents with different polarities showed very little change, indicating that the modified compounds do not form charge transfer states. TD-DFT calculations and measurements performed at low temperature (78 K) and in viscous solvents revealed that the N-alkyl and N,N-dialkyl carboxamide groups tend to reduce the contributions from intersystem crossing and increase those from internal conversion. Considering that the fluorescence mechanism of low-fluorescence carbonyl compounds such as aldehyde and ketone is dominated by intersystem crossing and that of high-luminescence carbonyl compounds such as carboxylic acid and ester is dominated by a radiative process, it can be said that the photophysical process of N-alkyl and N,N-dialkyl carboxamides is novel. In addition, the calculation results for excited states indicated that such contributions can be controlled by selecting the appropriate polycyclic aromatic hydrocarbon or amide structure, in addition to solvent viscosity and temperature. PMID:22458253

Niko, Yosuke; Hiroshige, Yuki; Kawauchi, Susumu; Konishi, Gen-ichi

2012-04-20

 
 
 
 
81

International migration - OECD  

...International migration &ndash OECD, Migration at the Development Centre Data and research on international migration including migration stocks and flows, immigrants ..., Can migration contribute to economic progress? Work of the Development Centre on Migration and Development demonstrates the gains from increased international labour ... international migration, migration stocks, migrant flows, immigrants, labour market, integration, discrimination, migration,labour mobility,development, globalisation,policy ...coherence,remittances,centre International migration - OECD Français Follow us E-mail Alerts Blogs OECD Home About Countries Topics Statistics Newsroom OECD Home › International ...

82

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

Science.gov (United States)

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

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

2013-09-01

83

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)

84

Secondary parkinsonism  

Science.gov (United States)

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

85

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

86

Plant hydrocarbon recovery process  

Energy Technology Data Exchange (ETDEWEB)

A process for production and recovery of hydrocarbons from hydrocarbon-containing whole plants in a form suitable for use as chemical feedstocks or as hydrocarbon energy sources which process comprises: (A) pulverizing by grinding or chopping hydrocarbon-containing whole plants selected from the group consisting of euphorbiaceae, apocynaceae, asclepiadaceae, compositae, cactaceae and pinaceae families to a suitable particle size, (B) drying and preheating said particles in a reducing atmosphere under positive pressure (C) passing said particles through a thermal conversion zone containing a reducing atmosphere and with a residence time of 1 second to about 30 minutes at a temperature within the range of from about 200* C. To about 1000* C., (D) separately recovering the condensable vapors as liquids and the noncondensable gases in a condition suitable for use as chemical feedstocks or as hydrocarbon fuels.

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

1982-01-26

87

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

88

Model migration schedules incorporating student migration peaks  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

89

Dehydrogenation of dehydrogenatable hydrocarbons  

International Nuclear Information System (INIS)

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

90

Plasma Processing Of Hydrocarbon  

Energy Technology Data Exchange (ETDEWEB)

The Idaho National Laboratory (INL) developed several patented plasma technologies for hydrocarbon processing. The INL patents include nonthermal and thermal plasma technologies for direct natural gas to liquid conversion, upgrading low value heavy oil to synthetic light crude, and to convert refinery bottom heavy streams directly to transportation fuel products. Proof of concepts has been demonstrated with bench scale plasma processes and systems to convert heavy and light hydrocarbons to higher market value products. This paper provides an overview of three selected INL patented plasma technologies for hydrocarbon conversion or upgrade.

Grandy, Jon D; Peter C. Kong; Brent A. Detering; Larry D. Zuck

2007-05-01

91

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.)

92

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

93

Migration patterns in India.  

Science.gov (United States)

"The chief objective of the present paper is to comprehend the broad spatial patterns of internal migrations in India." Aspects considered include data constraints, the magnitude of internal migration, interstate migration, migration to rural and to urban destinations, spatial patterns, and areas of origin and destination. PMID:12179044

Smita; Chandna, R C

1991-01-01

94

International Migration and Remittances  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

95

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

96

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

97

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

98

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

Science.gov (United States)

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

Ali, A. A.; SOC Team

2013-05-01

99

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.

100

Process for hydroforming hydrocarbon liquids  

International Nuclear Information System (INIS)

This patent describes a process for hydroforming hydrocarbon liquids contacting the hydrocarbon liquids with water and hydrogen in the presence of a mixed- solid solution tri-metallic oxide/sulfide catalyst having the formula: MIOaSbMIIOcMIIIOd

 
 
 
 
101

Lymphocyte migration studies  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Bimczok, Diane; Rothko?tter, Hermann

2006-01-01

102

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

103

Plant hydrocarbon recovery  

Energy Technology Data Exchange (ETDEWEB)

A process for production and recovery of hydrocarbons from whole plants in a form suitable for use as chemical feedstocks or as hydrocarbon energy sources comprises: pulverizing by grinding or chopping the plants to a suitable particle size, drying and preheating the particles in a reducing atmosphere under positive pressure, passing the particles through a thermal conversion zone containing a reducing atmosphere and with a residence time of 1 s to approximately 30 min at approximately 200-1000 degrees, and separately recovering the condensable vapors as liquids and the noncondensable gases in a condition suitable for use as chemical feedstocks or as hydrocarbon fuels. Thus 1 g of dried Euphorbia marginata was thermally decomposed at 950/sup 0/. The respective yields of char, liquid products, CO, CO/sub 2/, CH/sub 4/, acetylene, ethylene, and total hydrocarbons were 31.1, 12.6, 13.3, 17.7, 3.9, 1.1, 4.0, and 21.6%.

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

1982-01-26

104

Zeroing in on hydrocarbons  

Energy Technology Data Exchange (ETDEWEB)

The increasing costs of remediating contaminated sites has stimulated research for cost-reducing techniques in soil investigation and cleanup techniques. MAP Environmental Research has developed a technology using ground penetrating radar in combination with in house developed software to locate and define the extent of hydrocarbon contamination. This article discusses the new technology. 2 figs.

Roest, I.P.B. van der; Brasser, D.J.S.; Wagebaert, A.P.J.; Stam, P.H. [MAP Environmental Research BV, Arnhem (Netherlands)

1997-05-01

105

Subsurface distribution of hydrocarbons in the Building 403 Area at LLNL  

Energy Technology Data Exchange (ETDEWEB)

The loss of 9000 to 17,500 gallons of regular gasoline from an underground tank in the Building 403 area was investigated. Samples of saturated and unsaturated soil and ground water were collected and analyzed for total gasoline hydrocarbons and/or aromatic hydrocarbons. These data have defined the vertical and lateral extent of hydrocarbons in soil and ground water in the Building 403 area. Ground water analyses indicate that the aromatic constituents of gasoline, benzene, toluene, and xylenes (BTX) have not migrated horizontally as far as 200 ft southwest, 250 ft west, and 500 ft northwest, northeast, and east from the suspected leak. Low concentrations of benzene in wells 300 ft north and 350 ft southeast of the suspected leak indicate these wells are at or near the fringe of the BTX plume in ground water. Ground water analyses also indicate BTX has not migrated as deep as 185 ft below ground surface near the suspected leak. Short chain alphatic gasoline hydrocarbons have been detected in ground water in higher concentrations and further from the suspected leak than the aromatic hydrocarbons, suggesting that the short chain hydrocarbons are more mobile and may represent the leading edge of a hydrocarbon plume. In saturated soil, BTX in concentrations greater than 100 ppM appears to have migrated preferentially to the southwest and northwest from the leak. Beneath the leak, BTX concentrations greater than 1 ppM in unsaturated soil extend from about 20 ft to the water table, about 100 ft below ground surface. Existing data indicate BTX in concentrations greater than 1 ppM has preferentially migrated about 100 ft northwest of the suspected leak while similar BTX concentrations extend about 50 ft in other directions. The highest concentrations of gasoline hydrocarbons in both saturated and unsaturated soil occur in finer grained sediments, probably as a result of greater sorption in such materials.

Dresen, M.D.; Hoffman, F.; Lovejoy, S. Jr.

1986-07-01

106

Secondary Headaches  

Science.gov (United States)

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

107

Genesis of carbonates and formation of hydrocarbons under geological-temporal aspects  

Energy Technology Data Exchange (ETDEWEB)

The authors attempt a reconstruction of the influence of time on carbonate genesis (using the example of the Stassfurt carbonate) and try to define the period of hydrocarbon genesis under the aspects of time and stratigraphy. The solution throws a light on some central problems of hydrocarbon prospecting. From the geological indications, the kerogen type characteristics, and the specific coalification history the author arrives at the conclusion that the genesis, migration and accumulation of the hydrocarbons in the Stassfurt carbonate rocks date back to the pre-alpine interval.

Piske, J.; Bleschert, K.H.

1986-01-01

108

Obtaining hydrocarbons from ethanol over iron-modified ZSM-5 zeolites  

Energy Technology Data Exchange (ETDEWEB)

The search for new energy sources has impulsed hydrocarbon production from methanol and ethanol over ZSM-5 zeolites. Iron incorporation by different methods has led to a variety of chemical applications. Thus, hydrocarbon production from ethanol was studied over a ZSM-5 zeolite modified by ion exchange and impregnation with iron. XRD, FTIR, TPR, nitrogen adsorption, Moessbauer and photoacoustic spectroscopies were used for the samples characterization. The highest yield of liquid hydrocarbons was obtained with the low iron-exchanged zeolite, especially co-feeding hydrogen. The calcination procedure led to a migration of the iron species, probably forming iron oxide particles. 15 refs., 7 figs., 1 tab.

Nadia Regina Camargo Fernandes Machado; Valmir Calsavara; Nelson Guilherme Castelli Astrath; Celia Kimie Matsuda; Andrea Paesano Junior; Mauro Luciano Baesso [Universidade Estadual de Maringa, Maringa (Brazil). Departamento de Engenharia Quimica

2005-11-01

109

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

110

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

111

Biogeochemistry of Halogenated Hydrocarbons  

Science.gov (United States)

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

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

2003-12-01

112

THERMOCHEMISTRY OF HYDROCARBON RADICALS  

Energy Technology Data Exchange (ETDEWEB)

Gas phase negative ion chemistry methods are employed to determine enthalpies of formation of hydrocarbon radicals that are important in combustion processes and to investigate the dynamics of ion-molecule reactions. Using guided ion beam tandem mass spectrometry, we measure collisional threshold energies of endoergic proton transfer and hydrogen atom transfer reactions of hydrocarbon molecules with negative reagent ions. The measured reaction threshold energies for proton transfer yield the relative gas phase acidities. In an alternative methodology, competitive collision-induced dissociation of proton-bound ion-molecule complexes provides accurate gas phase acidities relative to a reference acid. Combined with the electron affinity of the R {center_dot} radical, the gas phase acidity yields the RH bond dissociation energy of the corresponding neutral molecule, or equivalently the enthalpy of formation of the R{center_dot} organic radical, using equation: D(R-H) = {Delta}{sub acid}H(RH) + EA(R) - IE(H). The threshold energy for hydrogen abstraction from a hydrocarbon molecule yields its hydrogen atom affinity relative to the reagent anion, providing the RH bond dissociation energy directly. Electronic structure calculations are used to evaluate the possibility of potential energy barriers or dynamical constrictions along the reaction path, and as input for RRKM and phase space theory calculations. In newer experiments, we have measured the product velocity distributions to obtain additional information on the energetics and dynamics of the reactions.

Kent M. Ervin, Principal Investigator

2004-08-17

113

Holes in hydrocarbons  

International Nuclear Information System (INIS)

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

114

South Korea: An overlooked hydrocarbon province  

Energy Technology Data Exchange (ETDEWEB)

A forthcoming well about to spud off South Korea is planned to test the potential of an essentially unexplored rift basin. Should the well prove successful, it could open up a major new hydrocarbon producing province with substantial reserves. The well is being drilled in Block V which covers 7,000 sq km. is divided into two parts, and lies about 150 km south of the Korean peninsula close to Cheju Island. The larger Northern Block overlies the Fukue basin, which is a linear graben system oriented northeast-southwest. The Fukue basin is equivalent in size to the South Viking graben of the North Sea and the existence of a restricted marine source rock and play types at several stratigraphic levels helps to reinforce such a comparison Seismic mapping has revealed five prospects with combined most likely reserves of more than 1 billion bbl. The paper describes the basin evolution, source and migration of petroleum, reservoir and seals, and well location.

Sturt, D.C.; Quinton, N.A. (Dragon Oil plc, Harpenden (United Kingdom))

1993-11-01

115

International migration - OECD  

...including migration stocks and flows, immigrants in the labour market, integration and discrimination., At the occasion of the International Migrants Day on ...Wednesday 18 December, the OECD raises attention on the issue of discrimination against immigrants and their children in OECD countries. international migration, migration ...stocks, migrant flows, immigrants, labour market, integration, discrimination, International Migrants Day, Wednesday 18 December, International migration - OECD Français Follow us ...Day on Wednesday 18 December, the OECD raises attention on the issue of discrimination against immigrants and their children in OECD countries. Discrimination is ...

116

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

117

Frontières et migrations - Introduction  

Directory of Open Access Journals (Sweden)

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

Catherine de Wenden

2013-10-01

118

Enzymatic oxygenation of hydrocarbons  

Energy Technology Data Exchange (ETDEWEB)

Oxygenases, those enzymes catalyzing the incorporation of oxygen atoms derived exclusively from molecular oxygen into organic substrates, are ubiquitous in nature. The degradation and detoxification of hydrophobic materials such as aliphatic and aromatic hydrocarbons is initiated by monooxygenases to yield alcohols and phenols, respectively. In man and higher organisms, these initial metabolic products are conjugated with a hydrophilic moiety and excreted; in contrast, microbes are capable of metabolizing hydrocarbons completely to CO/sub 2/ and H/sub 2/O. In the case of aromatics, the initially formed phenols are further hydroxylated to catechols, which are substrates for dioxygenase-catalyzed ring clevages. The products of the dioxygenase reactions are easily converted to simple substrates such as acetate and succinate; thus, the microbial non-heme iron dioxygenases are critical for the degradation of natural and synthetic aromatic compounds in the environment. In recent years, both mono and dioxygenases have become the subject of intensive research, with molecular-level information becoming available for both mammalian and microbial enzymes. Among the monooxygenases, there is no doubt that the cytochrome P-450 containing enzymes have been the most intensively studied. In this presentation, we will discuss recent work with protocatechuate-3,4-dioxygenase (PCD), which catalyzes the intradiol clevage of 3,4-dihydroxybenzoic acid (protocatechuic acid) to give ..beta..-carboxy-cis, cis-muconic acid.

Phillips, R.S.; May, S.W.

1979-08-01

119

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

Directory of Open Access Journals (Sweden)

Full Text Available The influence of heuristical strategies upon the level of two experimental classes is studied in this paper. The didactic experiment took place at secondary school in Cluj-Napoca, in 2008-2009 school year. The study theme “The Unsaturated Hydrocarbons – Alkenes” has been efficiently learned by using the most active methods: laboratory experiment, brain storming, modeling, problematization. The results obtained in the research demonstrate the efficiency of interactive methods in teaching-learning process.

Adrienne Kozan Naumescu

2011-03-01

120

Uranium and bitumen migration in hydrothermal solutions  

International Nuclear Information System (INIS)

Results of studying uraniferous bitumens in deposits of the Siberian plateau are presented. It is shown that both bituminosity and uranium mineralization, connected with it, are secondary and confined to the zones of high permeability. Uranium confinement to hydrocarbon-water inclusions is detected, that indicates to their combined transport in a hydrothermal system. It is established that in uraniferous bitumens titanium, iron, thorium, zirconium, lanthanum, yttrium, and cerium are accumulated. In accordance with the above information, bitumens and uranium in Proterozoic-Early Paleozoic deposits of the Siberian plateau are presented as evolution products of the unitary hydrothermal system, which arrival in a sedimentary cover is connected with later fractures

 
 
 
 
121

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

122

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 experiments, a key point of disagreement between theory and observation. It is shown that the disagreement between model results and field observations can arise from how seed migration dynamics is incorporated. Two approaches to biomass movement are used to test the hypothesis that secondary seed dispersal in overland flow inhibits band migration. The first is based on a coupling between down-slope water transport and seed advection. The second uses a heavy-tailed kernel-based representation of seed transport in which an anisotropic dispersal kernel combines the effect of isotropic primary and downslope secondary seed dispersal. This approach 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.

Katul, G. G.; Thompson, S.

2008-12-01

123

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

124

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

2006-01-01

125

Carbon neutral hydrocarbons.  

Science.gov (United States)

Reducing greenhouse gas emissions from the transportation sector may be the most difficult aspect of climate change mitigation. We suggest that carbon neutral hydrocarbons (CNHCs) offer an alternative pathway for deep emission cuts that complement the use of decarbonized energy carriers. Such fuels are synthesized from atmospheric carbon dioxide (CO2) and carbon neutral hydrogen. The result is a liquid fuel compatible with the existing transportation infrastructure and therefore capable of a gradual deployment with minimum supply disruption. Capturing the atmospheric CO2 can be accomplished using biomass or industrial methods referred to as air capture. The viability of biomass fuels is strongly dependent on the environmental impacts of biomass production. Strong constraints on land use may favour the use of air capture. We conclude that CNHCs may be a viable alternative to hydrogen or conventional biofuels and warrant a comparable level of research effort and support. PMID:18757281

Zeman, Frank S; Keith, David W

2008-11-13

126

ENVIROMENTAL HYDROCARBON CONTAMINATION IN RICOTTA AND MOZZARELLA DI BUFALA CHEESE  

Directory of Open Access Journals (Sweden)

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

M Panzardi

2013-02-01

127

Migration og etnicitet  

DEFF Research Database (Denmark)

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

Christiansen, Connie CarØe

2004-01-01

128

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.

129

Remittances and return migration  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper utilises survey data of return migrants to analyse the determinants of remittances sent while the migrants were abroad. We approach our research question from the perspective of three sending countries in the Maghreb, namely Algeria, Morocco and Tunisia. We investigate the remittance behaviour using the migrants' conditions before migration as well as during the migration experience. Using a two-part model, we show that the decision to remit and the amount remitted depend on a comb...

Collier, William; Piracha, Matloob; Randazzo, Teresa

2011-01-01

130

Migration and Narration  

Directory of Open Access Journals (Sweden)

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

Brigitte Boenisch-Brednich

2002-05-01

131

The dynamics of neuronal migration.  

Science.gov (United States)

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

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

2014-01-01

132

Diffusion of hydrocarbons from HDPE and f-HDPE geomembranes  

Energy Technology Data Exchange (ETDEWEB)

Geomembrane liners are used in landfills to prevent the migration of contaminants. They are also used at storage tank sites to control the impact of past spills and to minimize potential damage from future spills. Although high density polyethylene (HDPE) geomembranes are relatively impermeable to the actual flow of liquids, studies have shown that some organic contaminants can readily diffuse through them. The diffusion of volatile organic compounds (VOCs) such as benzene, toluene and xylenes from an aqueous solution can be reduced significantly by applying a fluorine layer to the surface of a conventional HDPE geomembrane. This study examined the potential diffusion of hydrocarbons from HDPE and fluorinated HDPE (f-HDPE) geomembranes when exposed to solvents such as neat methanol, Jet fuel A-1 dissolved in methanol, and neat Jet fuel A-1. Immersion tests were performed for each solvent. The hydrocarbon content of the samples was monitored in order to determine the effect of the solvent on the geomembrane. In the methanol immersion test, heavier hydrocarbons diffused from the geomembrane. It was found that hydrocarbon fraction of Jet fuel A-1 changed when exposed to both conventional HDPE and fluorinated HDPE geomembranes. When HDPE and f-HDPE geomembranes were immersed in methanol, hydrocarbons diffused out of the geomembranes and into the methanol. HDPE and f-HDPE geomembranes immersed in Jet A-1 and Jet A-1 dissolved in methanol. The hydrocarbon distribution changed relative to that of the original solvent/solution. Experiments performed on neat Jet A-1 resulted in an increase in the lightest fraction compared to Jet A-1 standard. When Jet A-1 was dissolved in methanol, there were changes to the lowest examined hydrocarbon fraction and the heavier carbon fractions. Hydrocarbons were found to diffuse out of both HDPE and f-HDPE geomembranes exposed to high concentrations or neat solvents. It was concluded that the results from sorption, desorption and diffusion tests on neat solutions should be interpreted with caution because the outward diffusion of waxes may result in misinterpretation of the data. 19 refs., 3 tabs., 9 figs.

Lindsay, H.J. [AMEC Earth and Environmental Ltd., Mississauga, ON (Canada); Rowe, K. [Royal Military Coll. of Canada, Kingston, ON (Canada). GeoEngineering Centre

2005-07-01

133

Subduction zone earthquake probably triggered submarine hydrocarbon seepage offshore Pakistan  

Science.gov (United States)

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

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

2014-05-01

134

Angle gathers for Gaussian beam depth migration  

Energy Technology Data Exchange (ETDEWEB)

Seismic data offers useful information about seismic velocity and rock properties at a time when hydrocarbon exploration is focusing on deeper, more subtle targets beneath geologically complex overburden. However, the reliability of standard velocity analysis and amplitude variation with offset (AVO) analysis has diminished because the velocities estimated in complex structure by standard velocity analysis are inaccurate, and because the amplitudes are affected by propagation effects that disregard the assumptions of standard AVO. This study focused on migrated common-image-gathers (CIGs), which are important to prestack depth migration because they enable seismic velocity estimation by tomography and other methods. They also enable the analysis of seismic amplitudes in moderately complex structures. CIGs have historically been indexed by source-receiver offset, measured along the Earth's surface. For decades, unstacked gathers of seismic data have provided information about seismic velocity and rock properties. On common-midpoint gathers of unmigrated data, this information has come from moveout and amplitudes. Moveout refers to the behavior of travel times as a function of source-receiver offset above a reflector. It is related to the average velocity between the Earth's surface and the reflector. Amplitudes are related to reflection coefficients at reflectors. These are related to changes on rock properties occurring at rock boundaries. New CIGs indexed by opening angle at subsurface image locations have advantages over offset-indexed CIGs. These gathers allow the modification of tomography programs to use pairs of ray paths more naturally than before, and they allow amplitude analysis as a function of opening angle rather than offset. Another type of CIG, occurring naturally in migrations that use a synthesized linear source, is indexed by the incidence angle of the linear source at the Earth's surface. Gaussian beam migration can readily produce offset-indexed CIGs. Various ways of producing these types of CIGs were presented along with their relative advantages. 4 refs., 3 figs.

Gray, S. [Veritas DGC Inc., Calgary, AB (Canada)

2006-07-01

135

Globalization, Migration and Development  

Directory of Open Access Journals (Sweden)

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

George, Susan

2002-01-01

136

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

137

Predicting hydrocarbon release from soil  

Energy Technology Data Exchange (ETDEWEB)

'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 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)

Poppendieck, D.G.; Loehr, R.C. [Univ. of Texas at Austin, Austin, Texas (United States)

2002-06-15

138

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

139

Maritime hydrocarbon pollution: Intervention  

International Nuclear Information System (INIS)

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

140

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

 
 
 
 
141

Volatile hydrocarbon detector apparatus  

International Nuclear Information System (INIS)

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

142

Effects of lichens on uranium migration  

International Nuclear Information System (INIS)

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

143

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 UO2 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 UO2 have been derived by modelling the low-fluence data. (authors)

144

Governance in Nurse Migration  

Directory of Open Access Journals (Sweden)

Full Text Available 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 participating agencies: Commission on Filipino Overseas (CFO, Philippine Overseas Employment Administration (POEA, Commission on Higher Education (CHED, Professional Regulation Commission (PRC, and Department of Labor and Employment (DOLE. From the research materials, relevant data about governance on nurse migration were culled, organized and stratified for an in-depth, comprehensive and systematic content analysis. With this content analytic approach, five (5 factors emerged notably supportive of good governance; they are: (1 temporary and circular labor migration; (2 employment driven strategy via regulated channels; (3 reintegration goals via modes of incentives and engagements; (4 migration vis-a-vis remittances; and (5 migratory realism on the ethics of recruitment. Theoretically, the factors could demonstrate the governments proactive stance on good governance but much remain to be seen in terms of the ethics of recruitment, reintegration goals and migration-development nexus.

S. Ma. Remegia M. Cirujales

2012-09-01

145

Hydrocarbon fluidization of fossil coals  

Energy Technology Data Exchange (ETDEWEB)

Concepts of metasomatosis and fluidization are discussed with regard to caustobioliths, which have not previously been considered, despite their important role in petrogenesis and ore formation. The paper refers to recent research which has revealed the endogenetic nature of the basic hydrocarbon mass in ore-bearing formations, which were formed in displacement zones by fluidization and metasomatosis of metapelites. It was found that phyllite and aspide shale strata provide optimum conditions for formation of endogenetic hydrocarbons, similar to those found in experimental and industrial hydrocarbon conversion processes. Geotectonic situations of important coal basins show that hydrocarbon fluidization and metasomatosis occur in them with an even greater intensity than in miogeosynclines and parageosynclines. Experiments are described to model hydrocarbon fluidization of fossil coals in an autoclave at temperatures of 100-200 C and pressures of 1-50 bar using various classes of finely crushed coal for periods of 10-80 minutes. Results were measured by vacuum decryptometry and spectral methods were used to fix efflux of metals (Fe, Mn, Zn, Mg, Al) and sulfur from the carbonization zone. Results confirm that hydrocarbon fluidization processes play an important part in formation of the main lithotypes of coal (vitrain, clarain, etc.) and should be included in future petrological and geochemical research into caustobioliths, basin zoning and industrial coal classification and quality forecasting.

Ivankin, P.F.; Trufanov, V.N.

1987-01-01

146

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

Energy Technology Data Exchange (ETDEWEB)

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

Van Stempvoort, D.R. [Environment Canada, Burlington, ON (Canada); Armstrong, J. [Alberta Univ., Edmonton, AB (Canada)]|[WorleyParsons Komex Environmental, Calgary, AB (Canada); Biggar, K. [Alberta Univ., Edmonton, AB (Canada)]|[BGC Engineering Inc., Edmonton, AB (Canada)

2007-07-01

147

A Generic Process Migration Algorithm  

Directory of Open Access Journals (Sweden)

Full Text Available Process migration has been advocated as a means of improving multicomputer configuration performance. The optimized migration algorithm utilized in migration event has direct effect on the efficiency and deployment of the process migration system. However, every design has preference factors results in concentration on specific aspect of the migration algorithm. There is no generic migration algorithm which could satisfy all circumstances with almost reasonable costs. This paper reviews the major issues which constitute the developer concerns when implementing a process migration algorithm. This examination indicates the existence of similarity in all process migration algorithms. A new migration algorithm is given and compared to the other algorithms. This algorithm attempts to integrate the significant features of the existing algorithms to form a generic algorithm.

Amirreza Zarrabi

2012-10-01

148

What's driving migration?  

Science.gov (United States)

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

Kane, H

1995-01-01

149

Migration of seismic data  

Energy Technology Data Exchange (ETDEWEB)

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

Bonomi, E.; Cabitza, G. [Research and Development in Sardinia, Cagliari (Italy)

1994-07-01

150

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

151

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

152

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

153

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Kolesnikov, Anton

2010-01-01

154

Anterior migration of spinal cord after cervical corpectomy.  

Science.gov (United States)

Posterior migration of spinal cord is a common complication of posterior cervical decompression, whereas anterior migration of spinal cord after anterior cervical decompression has not been reported previously. This report presents a case of anterior migration of spinal cord after cervical corpectomy. A 65-year-old male underwent a cervical corpectomy of the C4 and C5 for cervical spondylotic myelopathy. The postoperative MRI showed that spinal cord was decompressed. However, at 12 months postoperatively, the patient complained that improved gait aggravated again, and the MRI showed an anterior migration of the spinal cord at the level of the C4 and C5, and a compression of spinal cord at the level of caudal endplate of C3. Secondary surgery, laminaplasty of C3 and C4 was conducted. The postoperative MRI showed that the spinal canal increased at the C3 and C4 levels, and the spinal cord went through smoothly without sharp turning. PMID:21643826

Qian, Yu; Xu, Guojian; Zhang, Jun; Zhao, Xiaofeng; Wen, Dong

2012-06-01

155

Enhanced migration of seismic data  

Energy Technology Data Exchange (ETDEWEB)

The so-called enhanced migration which uses diffraction tomography as the repair tool for correction of amplitudes (reflection coefficients) of migrated sections is discussed. As with any linearized procedure, diffraction tomography requires knowledge of the initial model. It is suggested that the initial model is taken as the migrated image. It will be demonstrated that diffraction tomography applied to the data residuals improves the amplitudes of the migrated images. Migration is redefined as the reconstruction of the wavefront sets of distributions (reflection interfaces), and the inversion process as tomographic correction of migrated images.

Carrion, P.M. (PPPG/UFBA, Instituto de Geociencias, Rua Gaetano Moura 123, Federacao, 40.210 Salvador, Bahia (BR))

1990-10-01

156

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

157

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

158

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)

159

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

160

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 tables

 
 
 
 
161

Canadian Migration Monitoring Network  

Science.gov (United States)

This 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.

2008-01-02

162

PROSPECTIVE DES MIGRATIONS CLIMATIQUES  

Digital Repository Infrastructure Vision for European Research (DRIVER)

La science de la population ne peut se prononcer ni sur le calendrier ni sur l'intensité géographiquement variable des évolutions climatiques. En revanche, en partant de l'hypothèse la plus répandue d'un réchauffement moyen de la planète, elle peut proposer trois types de migrations climatiques.

Dumont, Ge?rard-franc?ois

2007-01-01

163

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

Science.gov (United States)

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

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

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 quality of the Fredericton water supply. 6 refs., 2 figs

166

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

167

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

168

TOWARD MIGRATION TRANSITION IN ROMANIA  

Directory of Open Access Journals (Sweden)

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

Cristian Incaltarau

2012-12-01

169

Radionuclide migration studies in soil  

International Nuclear Information System (INIS)

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

170

Data Migration - Research Councils UK  

... Funding across the UK · Environmental Policy Statement for Polaris House ... A \\migration exercise has taken place to move existing outcomes data to the new ... \\Queries relating to data migrated from ROS should be referred directly to the ...

171

Hydrocarbon habitat in rifted basins  

Energy Technology Data Exchange (ETDEWEB)

Tectonically active rifts, palaeo-rifts and passive margin basins contain major hydrocarbon provinces. Their hydrocarbon charge can rely exclusively on pre-rift, syn-rift sedimentary sequences or a combination thereof. Maturation of source-rocks can be achieved during the syn-and/or post-rift stage of basin evolution. During rifting, conductive and convective heat transfer accounts for elevated geothermal gradients; these play an important role in the maturation of pre- and syn-rift source-rocks; as geothermal gradients decrease asymptotically during the post-rift stage, maturation of late syn- and post-rift source-rocks depends on massif overburden thicknesses. In most rift structuration and trap-formation predate or are contemporaneous with peak oil and gas generation. Post-rift subsidence and stress-induced basin tilting or inversion can cause modification of trap configurations, causing loss of hydrocarbons. (author). 58 refs., 1 fig., 1 tab.

Ziegler, P.A. [Basel Univ. (Switzerland)

1996-12-01

172

Migration flows management in Latvia  

Directory of Open Access Journals (Sweden)

Full Text Available The present-day world features ever growing mobility - free movement of people, financial capital, markets and services. This mobility is enhanced and arranged by cross-national networks. The major instrument driving migration is modern technologies and information, including internet, communications and cheap air travels. The article makes insight into external migration trends of labour force and migration flows management prospects so as to discover the possible solutions for further formation of migration policy in Latvia.

Inga Shina

2009-12-01

173

GRT migration of VSP data  

Energy Technology Data Exchange (ETDEWEB)

This paper reports that VSP migration is of great significance to good VSP application. The formula of generalized Radon transform (GRT) migration of VSP data is derived from Radon transform principle, scalar wave equation and the geometric optical property of Green's function solution. GRT migration results of modeled VSP data and real VSP data show that GRT migration is high adaptable and accurate to the image of complicated geological structure.

Yong, W.; Chengchu, L. (Computer Center, Jiangsu Petroleum Exploration Bureau, P.O. Box 4608, Nanjing City, Jiangsu Province (China))

1992-01-01

174

Method of migrating seismic records  

Science.gov (United States)

The present invention provides a method of migrating seismic records that retains the information in the seismic records and allows migration with significant reductions in computing cost. The present invention comprises phase encoding seismic records and combining the encoded seismic records before migration. Phase encoding can minimize the effect of unwanted cross terms while still allowing significant reductions in the cost to migrate a number of seismic records.

Ober, Curtis C. (Las Lunas, NM); Romero, Louis A. (Albuquerque, NM); Ghiglia, Dennis C. (Longmont, CO)

2000-01-01

175

Two Centuries of International Migration  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

176

FACTORS AFFECTING INTERNATIONAL LABOR MIGRATION  

Directory of Open Access Journals (Sweden)

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

?.?. ???????

2012-03-01

177

Boundary Migration in Rutile  

Energy Technology Data Exchange (ETDEWEB)

TiO{sub 2} is a vital material in several technologies including, photocatalysis, gas sensing, biomaterials and optical coatings. Among the several crystal structures of this oxide, rutile has the highest density and microhardness, the highest index of refraction and the highest temperature stability. The processing of dense polycrystalline materials often includes the addition of a liquid-forming phase at higher temperatures. This technique is known as liquid-phase sintering and has been studied extensively. Rutile boundaries containing an amorphous phase have been used to study boundary migration and grain-boundary grooving. Visible-light (VLM), scanning electron (SEM) and transmission electron microscopy (TEM) in addition to electron-backscatter diffraction (EBSD) and a focused-ion beam (FIB) tool were used to characterize boundary migration in rutile. EBSD analysis was carried out on a Philips XL30 FEG SEM equipped with a DigiView 1612 high-resolution, high-speed CCD camera. A 2.5 cm sample-to-camera distance was used and {approx}70{sup o} sample tilt. A Philips CM30 operated at 300 kV was used for TEM characterization and an FEI DB235 was used for FIB work. Pulsed-laser deposition (PLD) has been used to deposit thin films ({approx}100 nm thick) of silica glass on single-crystals of rutile. The film/substrate assembly is then fabricated into bicrystals of known boundary-plane orientation by hot pressing. Bicrystals were fabricated with boundary planes of nominal surface orientation of (001) and (110). After diffusion bonding a surface perpendicular to the interface is cut and polished. Bicrystals are then heat treated in air at 1650 C for varying lengths of time. Figure 1 is a VLM image of a rutile bicrystal which as been heat treated for 4 hours. During this heat treatment migration of the boundary initiates at parallel grooves contained in the crystal on the right-hand side. EBSD analysis shows that this parallel set of grooves is due to the presence of 3{sup o} boundaries within this crystal. While the boundary migrates from the left to the right with respect to the image, the 3{sup o} boundaries propagate into the reprecipitated rutile. The (001) boundary plane and (110) free surface grow at the expense of the (110) boundary plane and (001) free surface (free surface determined by EBSD). A FIB was used to prepare a cross-section TEM specimen at the migrated boundary. The FIB section was taken from an area in which the migrated boundary was 40 {micro}m from the groove remnant. A wide and shallow groove is formed at this migrated boundary and is illustrated in the bright-field (BF) TEM image in Figure 2. Of particular interest in this image is the nearly 120{sup o} groove at the free surface (see schematic in Figure 3) and the location of the grain boundary. Often in EBSD analysis and grain-boundary grooving work, grain boundaries are assumed to have a perpendicular intersection to the free surface. This FIB-prepared specimen shows in this particular case, this assumption does not hold true. Due to the grooving at the free surface and therefore a reduction in energy at the free surface, the speed of migration is faster away from the surface. Figure 3 is a schematic of this migrated boundary. The original boundary consisted of (110) and (001) planes. The side with the (001) initial boundary plane migrates into the other crystal. A benefit of using a site-specific specimen preparation technique such as FIB allows for the grain-boundary profile to accurately be determined. A variety of microscopy techniques has been used to study boundary migration in rutile. Migration in this case has originated at low-angle boundaries. The groove formed at the free surface slows the rate of migration at the surface. FIB allows the profile of the groove to be determined accurately.

Gilliss, S.R.; Ravishankar, N.; Farrer, J.K.; Carter, C.B.

2003-08-01

178

Gender and Migration from Albania  

Science.gov (United States)

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

STECKLOV, GUY; CARLETTO, CALOGERO; AZZARRI, CARLO; DAVIS, BENJAMIN

2010-01-01

179

Migration of Interplanetary Dust  

CERN Document Server

We numerically investigate the migration of dust particles with initial orbits close to those of the numbered asteroids, observed trans-Neptunian objects, and Comet Encke. The fraction of silicate asteroidal particles that collided with the Earth during their lifetime varied from 1.1% for 100 micron particles to 0.008% for 1 micron particles. Almost all asteroidal particles with diameter d>4 microns collided with the Sun. The peaks in the migrating asteroidal dust particles' semi-major axis distribution at the n:(n+1) resonances with Earth and Venus and the gaps associated with the 1:1 resonances with these planets are more pronounced for larger particles. The probability of collisions of cometary particles with the Earth is smaller than for asteroidal particles, and this difference is greater for larger particles.

Ipatov, S I; Taylor, P A

2003-01-01

180

Dispersal and migration  

Directory of Open Access Journals (Sweden)

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

Bairlein, F.

2004-01-01

 
 
 
 
181

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

182

Erosion, Contamination, and Migration  

International Nuclear Information System (INIS)

This paper will summarize studies of carbon impurity sources, contamination, and migration developed through JET methane gas injection experiments. These studies were analyzed using the 2D SOL code EDGE2D/NIMBUS. The code is capable of repeating the JET analysis using the ITER geometry and SOL plasma. This allows assessment of whether the physical processes occurring in JET might also occur in ITER, and thus whether the JET results transfer, in any sense, to the ITER plasmas. Certainly, the ITER choice of wall materials (W and Be) is different than for the present JET C studies. So the present status of these studies is to relate JET carbon behavior to carbon in ITER.JET carbon sources were studied spectroscopically and analyzed with atomic physics models in EDGE2D. The carbon sources are dominated by chemical sputtering at rates which are within a factor-of-two of the published literature. The JET carbon contamination is dominated by main chamber sources which are ionized in the main chamber SOL about 1-2 cm from the separatrix. Contamination occurs from carbon ions which diffuse across the field lines and reach the separatrix before they can parallel transport to the divertor. JET carbon migration was studied by injecting methane composed of 13C on the last run day before an opening and then analyzing removed tiles to identify migration to those locations. Modeling was accomplished by the same EDGE2D models that were used to describe the carbon sources anere used to describe the carbon sources and contamination. The entire migration process is complicated.

183

Migration, trade and unemployment  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A source of anxiety of policy makers and the public in general is the detrimental impact of globalization 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 taking into account the substitutability of worker and goods flows. We use data from 24 OECD countries over...

Heid, Benedikt; Larch, Mario

2011-01-01

184

Migration, trade and unemployment  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

185

Raptor Center: Migration Tracking  

Science.gov (United States)

Part of the larger University of Minnesota Raptor Center site, this site features regularly updated location information on individual Hawks first captured on their breeding grounds in western Minnesota; they migrate to wintering grounds in central South America. Almost daily information is relayed from the birds to an Argos satellite, then to a receiving station in Maryland and finally to the Raptor Center. Users can follow 1996 individuals from St. Paul, MN to Caimanes, Bolivia.

1997-01-01

186

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2007-07-01

187

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.

188

Mechanisms of endothelial cell migration.  

Science.gov (United States)

Cell migration plays a central role in a variety of physiological and pathological processes during our whole life. Cellular movement is a complex, tightly regulated multistep process. Although the principle mechanisms of migration follow a defined general motility cycle, the cell type and the context of moving influences the detailed mode of migration. Endothelial cells migrate during vasculogenesis and angiogenesis but also in a damaged vessel to restore vessel integrity. Depending on the situation they migrate individually, in chains or sheets and complex signaling, intercellular signals as well as environmental cues modulate the process. Here, the different modes of cell migration, the peculiarities of endothelial cell migration and specific guidance molecules controlling this process will be reviewed. PMID:25038776

Michaelis, U Ruth

2014-11-01

189

Liquid Hydrocarbon Fuel Cell Development.  

Science.gov (United States)

A compound anode consists of a reforming catalyst bed in direct contact with a palladium-silver fuel cell anode. The objective of this study was to prove the feasibility of operating a compound anode fuel cell on a liquid hydrocarbon and to define the imp...

H. H. Heilbronner, W. P. Levins, J. W. Allison

1965-01-01

190

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

191

International Migration Diversification: A New Perspective to Migration Management  

Directory of Open Access Journals (Sweden)

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

Cynthia A. Bulley

2014-04-01

192

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

193

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2001-07-01

194

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

195

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

196

Biodegradation of petroleum hydrocarbons in hypersaline environments  

Scientific Electronic Library Online (English)

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

Luiz Fernando, Martins; Raquel Silva, Peixoto.

2012-09-01

197

Biodegradation of petroleum hydrocarbons in hypersaline environments  

Directory of Open Access Journals (Sweden)

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

2012-09-01

198

Biodegradation of petroleum hydrocarbons in hypersaline environments  

Scientific Electronic Library Online (English)

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

Luiz Fernando, Martins; Raquel Silva, Peixoto.

199

Evolved gas analysis of secondary organic aerosols  

Energy Technology Data Exchange (ETDEWEB)

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

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

1994-11-01

200

Migration experiments in Studsvik  

International Nuclear Information System (INIS)

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

 
 
 
 
201

Process for recovering hydrocarbons from hydrocarbon-containing biomass  

Energy Technology Data Exchange (ETDEWEB)

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

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

1982-07-06

202

Issues of Labor Migration  

Directory of Open Access Journals (Sweden)

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

Liliana Gheorghe

2010-12-01

203

Tolerance of Antarctic soil fungi to hydrocarbons  

Energy Technology Data Exchange (ETDEWEB)

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

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

2007-01-01

204

Radiological Management of Superior Vena Caval Stent Migration and Infection  

International Nuclear Information System (INIS)

We report a case of venous obstruction secondary to Hodgkin's lymphoma. Multiple Wallstents were inserted into the superior vena cava to relieve obstructive symptoms secondary to tumor. This procedure was complicated by stent migration into the right ventricle and a presumed stent infection. We describe the percutaneous management of these complications and discuss the issues surrounding the use of stents in this setting. We conclude that these complications can be managed percutaneously. However, the technical details of stent placement are essential in minimizing complications of this type

205

Migration and fate of ethanol-enhanced gasoline in groundwater: A modelling analysis of a field experiment  

Science.gov (United States)

Ethanol use as a gasoline additive is increasing, as are the chances of groundwater contamination caused by gasoline releases involving ethanol. To evaluate the impact of ethanol on dissolved hydrocarbon plumes, a field test was performed in which three gasoline residual sources with different ethanol fractions (E0: no ethanol, E10: 10% ethanol and E95: 95% ethanol) were emplaced below the water table. Using the numerical model BIONAPL/3D, the mass discharge rates of benzene, toluene, ethylbenzene, xylenes, trimethylbenzenes and naphthalene were simulated and results compared to those obtained from sampling transects of multilevel samplers. It was shown that ethanol dissolved rapidly and migrated downgradient as a short slug. Mass discharge of the hydrocarbons from the E0 and E10 sources suggested similar first-order hydrocarbon decay rates, indicating that ethanol from E10 had no impact on hydrocarbon degradation. In contrast, the estimated hydrocarbon decay rates were significantly lower when the source was E95. For the E0 and E10 cases, the aquifer did not have enough oxygen to support complete mineralization of the hydrocarbon compounds to the extent suggested by the field-based mass discharge. Introducing a heterogeneous distribution of hydraulic conductivity did little to overcome this discrepancy. A better match between the numerical model and the field data was obtained assuming partial degradation of the hydrocarbons to intermediate compounds. Besides depending on the ethanol concentration, the impact of ethanol on hydrocarbon degradation appears to be highly dependent on the availability of electron acceptors.

Freitas, Juliana G.; Mocanu, Marian T.; Zoby, José Luiz G.; Molson, John W.; Barker, James F.

2011-01-01

206

Migration, remittance and development in origin countries: evidence from Nigeria  

Directory of Open Access Journals (Sweden)

Full Text Available Migration (international or local migration of individuals/workers is viewed as a channel through whichworkers’ remittances have become a major source of income for developing countries; resources are repatriatedfrom the source country to service foreign nationals or home economy while it creates an internal braindrain between local migrants and likely an increased outmigration of workers/individuals. However, little isstill known about their impact on the economic development in the origin countries. This paper analyseswhether, and to what extent, these downsides of international migration of workers affects origin countries.Consequently, using a household survey-based and secondary sources dataset our results show that remittancesin Nigeria are positively and significantly viable in their contribution to economic growth (proxy bygross domestic product in some Sub-Saharan African countries and have reduced poverty to some extent.

John S. Afaha

2013-04-01

207

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

208

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

209

Kinetic models of hydrocarbon generation  

Energy Technology Data Exchange (ETDEWEB)

We are carrying out an integrated program of laboratory experiments, kinetics modeling, and basin thermal history modeling in order to better understand the natural breakdown of organic matter into oil and gas. Our kinetic models of organic maturation are being used to better understand the coupling of generation, cracking, expulsion, and overpressuring in both the laboratory and geologic setting. Currently we are carrying out chemical experiments and developing more efficient chemical kinetic modeling schemes to obtain a better understanding of expulsion and cracking from lean source rocks and from hydrogen-poor (terrestrial) organic source material. We verify the chemical kinetic models by integrating them with thermal history models of hydrocarbon-producing sediments and comparing predicted and observed characteristics of the hydrocarbon occurrence in a variety of settings. We intend to apply this approach to evaluate the potential for deep gas resources in the Pacific Northwest and in the Louisiana Gulf Coast. 11 refs., 4 figs.

Burnham, A.K.; Sweeney, J.J.

1990-10-25

210

Chemistry on Polycyclic Aromatic Hydrocarbons  

Science.gov (United States)

Chemistry on Polycyclic Aromatic Hydrocarbons Even though Polycyclic Aromatic Hydrocarbons (PAHs) are ubiquitous in the interstellar medium, the role they play as catalysts for interstellar chemistry is still largely unexplored. However, existing experimental data and theoretical calculations indicate that PAHs may well play a very active role, in particular in connection with the formation of molecular hydrogen. These findings may explain observations of increased molecular hydrogen formation rates in Photodissociation regions with high PAH abundances. In my talk I will present temperature programmed desorption data demonstrating the formation of highly super-hydrogenated PAHs via hydrogen addition reactions and catalytic formation of molecular hydrogen via abstraction reactions at a wide range of H atom temperatures. Approximate cross-sections for these reactions derived via model simulations will be presented. The implications for the role played by PAHs in interstellar chemistry will be discussed.

Hornekaer, Liv

211

International Migration and Human Development  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

212

Potential East-West Migration  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Hintermann, Christiane; Fassmann, Heinz

1998-01-01

213

Electrochemically induced nanocluster migration  

International Nuclear Information System (INIS)

In the presented study the influence of electrochemical treatments on size-selected Pt nanoclusters (NCs) supported on amorphous carbon is investigated by means of transmission electron microscopy (TEM). Well-defined Pt NCs are prepared by an ultra-high vacuum (UHV) laser vaporization source and deposited with low kinetic energy (?10 eV/cluster) onto TEM gold grids covered by a thin (2 nm) carbon film. After transfer out of UHV Pt NCs are verified to be uniform in size and randomly distributed on the support. Subsequently, the TEM grids are employed as working electrodes in a standard electrochemical three electrode setup and the Pt nanoclusters are subjected to different electrochemical treatments. It is found that the NC arrangement is not influenced by potential hold conditions (at 0.40 V vs. RHE) or by potential cycling in a limited potential window (Vmax = 0.55 V vs. RHE). Upon potential cycling to 1.05 V vs. RHE, however, the NCs migrate on the carbon support. Interestingly, migration in oxygen or argon saturated electrolyte leads to NC coalescence, a mechanism discussed for being responsible for performance degradation of low temperature fuel cells, whereas in carbon monoxide saturated electrolyte the Pt NC agglomerate, but remain separated from each other and thus form distinctive structures.

214

Electrochemically induced nanocluster migration  

Energy Technology Data Exchange (ETDEWEB)

In the presented study the influence of electrochemical treatments on size-selected Pt nanoclusters (NCs) supported on amorphous carbon is investigated by means of transmission electron microscopy (TEM). Well-defined Pt NCs are prepared by an ultra-high vacuum (UHV) laser vaporization source and deposited with low kinetic energy ({<=}10 eV/cluster) onto TEM gold grids covered by a thin (2 nm) carbon film. After transfer out of UHV Pt NCs are verified to be uniform in size and randomly distributed on the support. Subsequently, the TEM grids are employed as working electrodes in a standard electrochemical three electrode setup and the Pt nanoclusters are subjected to different electrochemical treatments. It is found that the NC arrangement is not influenced by potential hold conditions (at 0.40 V vs. RHE) or by potential cycling in a limited potential window (V{sub max} = 0.55 V vs. RHE). Upon potential cycling to 1.05 V vs. RHE, however, the NCs migrate on the carbon support. Interestingly, migration in oxygen or argon saturated electrolyte leads to NC coalescence, a mechanism discussed for being responsible for performance degradation of low temperature fuel cells, whereas in carbon monoxide saturated electrolyte the Pt NC agglomerate, but remain separated from each other and thus form distinctive structures.

Hartl, Katrin [Lehrstuhl Physikalische Chemie, Technische Universitaet Muenchen, Lichtenbergstr. 4, D-85748 Garching (Germany); Department of Chemistry, CS06, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen O (Denmark); Nesselberger, Markus [Department of Chemistry, CS06, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen O (Denmark); Mayrhofer, Karl J.J. [MPI fuer Eisenforschung, Abt. Grenzflaechenchemie und Oberflaechentechnik, Max-Planck-Strasse 1, D-40237 Duesseldorf (Germany); Kunz, Sebastian; Schweinberger, Florian F.; Kwon, GiHan [Lehrstuhl Physikalische Chemie, Technische Universitaet Muenchen, Lichtenbergstr. 4, D-85748 Garching (Germany); Hanzlik, Marianne [Institut fuer Elektronenmikroskopie, Technische Universitaet Muenchen, Lichtenbergstr. 4, D-85748 Garching (Germany); Heiz, Ueli [Lehrstuhl Physikalische Chemie, Technische Universitaet Muenchen, Lichtenbergstr. 4, D-85748 Garching (Germany); Arenz, Matthias, E-mail: m.arenz@kemi.ku.d [Department of Chemistry, CS06, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen O (Denmark)

2010-12-30

215

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

216

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.

217

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

218

Deep desulfurization of hydrocarbon fuels  

Science.gov (United States)

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

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

2012-04-17

219

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

220

Process migration in UNIX environments  

Science.gov (United States)

To support process migration in UNIX environments, the main problem is how to encapsulate the location dependent features of the system in such a way that a host independent virtual environment is maintained by the migration handlers on the behalf of each migrated process. An object-oriented approach is used to describe the interaction between a process and its environment. More specifically, environmental objects were introduced in UNIX systems to carry out the user-environment interaction. The implementation of the migration handlers is based on both the state consistency criterion and the property consistency criterion.

Lu, Chin; Liu, J. W. S.

1988-01-01

 
 
 
 
221

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

222

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

International Nuclear Information System (INIS)

ub>2-rich gas in two wells located close to the Midcontinent Rift in eastern Kansas, this study indicates that high levels of H2 may be a more widespread phenomenon than previously thought. Unlike previous results, the gases in this study have a significant component of hydrocarbon gas, as well as H2, N2, and CO2. Although redox reactions between iron-bearing minerals and groundwater are a possible source of H2 in the Precambrian basement rocks, the hydrocarbon gas does not exhibit the characteristics typically associated with proposed abiogenic hydrocarbon gases from Precambrian Shield sites in Canada, Finland, and South Africa. Compositional and isotopic signatures for gas from the no. 1 Wilson well are consistent with a predominantly thermogenic origin, with possible mixing with a component of microbial gas. Given the geologic history of uplift and rifting this region, and the major fracture systems present in the basement, this hydrocarbon gas likely migrated from source rocks and reservoirs in the overlying Paleozoic sediments and is not evidence for abiogenic hydrocarbons generated in situ in the Precambrian basement

223

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

Science.gov (United States)

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

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

2008-12-01

224

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

225

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

Energy Technology Data Exchange (ETDEWEB)

The theory of the abyssal abiotic petroleum origin considers oil and natural gas to be generated in the Earth's upper mantle. Hydrocarbons migrate further through the deep faults into the Earth's crust, where they can form oil and gas deposits in any kind of rock in any kind of structural position. Until recently one of the main obstacles for further development of this theory has been the lack of the data covering processes of generation and transformations of hydrocarbons. Experimental data, presented in this thesis, confirms the possibility of hydrocarbons formation from mantle inorganic compounds (water, Fe, CaCO{sub 3} or graphite) at temperature and pressure of the upper mantle (1500 K and 5 GPa). Experiments were carried out in CONAC high pressure device and multianvil apparatus BARS. Compositions of received gas mixtures were similar to natural gas. Quantity of hydrocarbons depended on the cooling regime of reaction mixture under pressure. Slow cooling favored higher quantity. We found that donor of carbon (CaCO{sub 3} or graphite) determines formation of 'dry' (methane-rich) gas or 'wet' (light hydrocarbons-rich) gas. Experiments in laser-heated diamond anvil cells showed that methane and ethane partially react under upper mantle thermobaric conditions (2-5 GPa, 1000-1500 K) to form mixture of hydrocarbons: methane, ethane, propane and n-butane - main compounds of natural gas. Similarity of final product mixture obtained from methane and ethane means thermodynamic stability of hydrocarbons in the thermobaric conditions of the upper mantle and equilibrium character of the observed processes

Kolesnikov, Anton

2010-12-15

226

IDChase: Mitigating Identifier Migration Trap in Biological Databases  

Science.gov (United States)

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

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

227

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

228

Objectivity Data Migration  

CERN Document Server

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

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

2003-01-01

229

Chandra Contaminant Migration Model  

Science.gov (United States)

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

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

2014-01-01

230

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

231

Migration and women's health.  

Science.gov (United States)

Women have been migrating at similar rates to men for the past 40 years, and comprised about half of all migrants in 2005. Women and children are most affected by displacement as a result of wars and human trafficking. In some cases, the health of female migrants is improved via integration into better health systems in the host country. More often, however, the health of female migrants is affected negatively. Women are doubly disadvantaged because they are discriminated against as women and as migrants. Female migrants are also highly vulnerable to acts of sexual abuse, rape, and violence. This is especially true for women in refugee camps, whose reproductive health needs are often overlooked. To improve the health of female migrants it is important to develop and implement policies that recognize and insist on the respect of the rights of migrants. PMID:19539929

Adanu, Richard M K; Johnson, Timothy R B

2009-08-01

232

Software Engineering Challenges of Migration Projects  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

233

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

234

Migration: the trends converge.  

Science.gov (United States)

Formerly, Australia, New Zealand, Canada, and the US have served as permanent destinations for immigrants, while Europe's migrants have moved to more northerly countries to work for a time and then returned home. From 1973-1975 Europe's recruitment of foreign workers virtually ended, although family reunion for those immigrants allowed in was encouraged. Problems resulting from this new settlement migration include low paying jobs for immigrant women, high unemployment, and inadequate education for immigrant children. Illegal migrants from Latin America and the Caribbean enter the US and Canada each year while illegal North African immigrants enter Italy, Spain, and Greece. North America, Australia, and Europe have all received political refugees from Asia and Latin America. Increasingly, these foreigners compete in the labor market rather than simply fill jobs the native workers do not want. All the receiving countries have similar policy priorities: 1) more effective ways for controlling and monitoring inflows and checking illegal immigration; 2) encouraging normal living patterns and accepting refugees; and 3) integrating permanent migrants into the host country. Europe's public immigration encouragement prior to the first oil shock, has left some countries with a labor force that is reluctant to return home. It is unlikely that Europe will welcome foreign labor again in this decade, since unemployment among young people and women is high and family reunion programs may still bring in many immigrants. Less immigration pattern change will probably occur in North America, Australia, and New Zealand since these countries' populations are still growing and wages are more flexible. Immigration, regulated by policy, and emigration, determined by market forces, now are working in the same direction and will likely reduce future migration flows. PMID:12267642

1985-09-01

235

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

DEFF Research Database (Denmark)

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

Skov, Christian; Aarestrup, Kim

2010-01-01

236

Late-Onset Screw Migration into Iliac Vessels 21 years after Hip Arthrodesis  

Science.gov (United States)

Iatrogenic injuries to the vascular system are a rare but serious complication of hip surgery. We report a case of an 83-year-old man who presented with intrapelvic migration of a screw into the space between the external iliac artery and vein 21 years after hip arthrodesis. The patient was treated with laparotomy, and the damaged artery was excised and sutured. This is the first case of a late vascular complication secondary to screw migration after hip arthrodesis. PMID:25336996

Hirai, Taishi; Inaba, Yutaka; Kobayashi, Naomi; Takakagawa, Shu; Yukizawa, Yohei; Ike, Hiroyuki; Saito, Tomoyuki

2014-01-01

237

Brine migration: a summary report  

International Nuclear Information System (INIS)

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

238

Before the Bonanza: Hydrocarbons in Greenland  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Meinild, Ebbe Dam

2010-01-01

239

HYDROCARBON AND SULFUR SENSORS FOR SOFC SYSTEMS  

Energy Technology Data Exchange (ETDEWEB)

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

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

2003-11-01

240

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...

 
 
 
 
241

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

242

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

243

Demetallization of hydrocarbon containing feed streams  

International Nuclear Information System (INIS)

This patent describes how metals contained in a hydrocarbon containing feed stream are removed by contacting the hydrocarbon containing feed stream under suitable demetallization conditions with hydrogen and a catalyst composition comprising zirconium phosphate, cobalt phosphate and iron phosphate. The life and activity of the catalyst composition may be increased by introducing a decomposable metal compound selected from the group consisting of the metals of Group V-B, Group VI-B, Group VII-B and Group VIII of the Periodic Table into the hydrocarbon containing feed stream prior to contacting the hydrocarbon containing feed stream with the catalyst composition

244

Detection of hydrocarbons in irradiated foods  

Energy Technology Data Exchange (ETDEWEB)

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)

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

2003-06-01

245

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)

246

Secondary Surveillance Radar Antenna  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Schejbal, Vladimi?r; Bezous?ek, Pavel; Pidanic?, Jan; Chyba, Milan

2013-01-01

247

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

248

Commercial valuation of hydrocarbon resources  

International Nuclear Information System (INIS)

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

249

Effective viscosity of confined hydrocarbons  

DEFF Research Database (Denmark)

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

Sivebæk, Ion Marius; Samoilov, V.N.

2012-01-01

250

Hyperaldosteronism - primary and secondary  

Science.gov (United States)

... hormone aldosterone into the blood. Hyperaldosteronism can be primary or secondary. ... Primary hyperaldosteronism is due to a problem of the adrenal glands themselves, causing them to release too ...

251

Migration of dispersive GPR data  

Science.gov (United States)

Electrical conductivity and dielectric and magnetic relaxation phenomena cause electromagnetic propagation to be dispersive in earth materials. Both velocity and attenuation may vary with frequency, depending on the frequency content of the propagating energy and the nature of the relaxation phenomena. A minor amount of velocity dispersion is associated with high attenuation. For this reason, measuring effects of velocity dispersion in ground penetrating radar (GPR) data is difficult. With a dispersive forward model, GPR responses to propagation through materials with known frequency-dependent properties have been created. These responses are used as test data for migration algorithms that have been modified to handle specific aspects of dispersive media. When either Stolt or Gazdag migration methods are modified to correct for just velocity dispersion, the results are little changed from standard migration. For nondispersive propagating wavefield data, like deep seismic, ensuring correct phase summation in a migration algorithm is more important than correctly handling amplitude. However, the results of migrating model responses to dispersive media with modified algorithms indicate that, in this case, correcting for frequency-dependent amplitude loss has a much greater effect on the result than correcting for proper phase summation. A modified migration is only effective when it includes attenuation recovery, performing deconvolution and migration simultaneously.

Powers, M.H.; Oden, C.P.

2004-01-01

252

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

Science.gov (United States)

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

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

2014-05-01

253

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

254

Modified residual migration of seismic data  

Energy Technology Data Exchange (ETDEWEB)

A method is described for migrating seismic events in the presence of a vertically- and laterally-varying velocity field, each said event being characterized by a raw input time, comprising: (a) scanning the true migration velocity field within an area of survey to define the minima of a true velocity function vs. time within the migration velocity field and defining a first stage function of migration velocity vs. time that is less than but approaches the minima of said true velocity field; (b) migrating at least one seismic event over a first migration pass with the aid of a preselected migration algorithm using a first migration velocity selected from said first stage function of velocity vs. time using as an argument, the raw input time of said at least one seismic event; (c) selecting a second velocity from said first stage function of migration velocity vs. time and selecting a true migration velocity from the true migration velocity function using as an argument the migrated time of said at least one seismic event; (d) defining a dip-dependent residual migration velocity as the square root of the difference between the squares of the selected true migration velocity and said selected second velocity; and (e) re-migrating the migrated seismic event using the residual migration velocity in conjunction with a desired migration algorithm.

Beasley, C.J.; Klotz, R.; Permata, T.

1993-08-03

255

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

Science.gov (United States)

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

Price, L C; Schoell, M

1995-11-23

256

Predicting hydrocarbon release from soil  

International Nuclear Information System (INIS)

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)

257

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)

258

Psychosocial Aspects of Migration  

Directory of Open Access Journals (Sweden)

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

Ayla Tuzcu

2014-02-01

259

Radial Migration in Spiral Galaxies  

CERN Document Server

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

Roškar, R

2014-01-01

260

Migration of Pu and Am  

International Nuclear Information System (INIS)

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

 
 
 
 
261

40 CFR 92.119 - Hydrocarbon analyzer calibration.  

Science.gov (United States)

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

2010-07-01

262

40 CFR 86.1221-90 - Hydrocarbon analyzer calibration.  

Science.gov (United States)

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

2010-07-01

263

40 CFR 89.319 - Hydrocarbon analyzer calibration.  

Science.gov (United States)

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

2010-07-01

264

40 CFR 86.1321-94 - Hydrocarbon analyzer calibration.  

Science.gov (United States)

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

2010-07-01

265

Mechanisms of secondary contamination of STS territory by man-caused radionuclides and methods of its prevention  

International Nuclear Information System (INIS)

Published data has been reviewed concerning formation mechanisms of secondary contamination in areas of radioactive fallout and possible methods to prevent it. Results of experimental researches on application interpolymeric complexes for the directed migration of radionuclides in ground, and also structurization and aggregation of ground for prevention of dust migration are given. (author)

266

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

267

Primary biodegradation of petroleum hydrocarbons in seawater  

Energy Technology Data Exchange (ETDEWEB)

This report describes primary biodegradation experiments performed to determine the persistence of higher molecular weight petroleum hydrocarbons in seawater. Results from the biodegradation experiments show that the majority of tested petroleum hydrocarbons have half-lives in seawater less than 60 days.

Comber, M.I.H.; Den Haan, K.H.; Djemel, N.; Eadsforth, C.V.; King, D.; Paumen, M.L.; Parkerton, T.; Dmytrasz, B.

2012-12-15

268

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)

269

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

270

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

Science.gov (United States)

As global warming occurs, the dissociation of bound methane on Arctic shelves due to ocean current temperature changes may become a major contributor to the global methane budget, and thus contribute to strong positive climate feedback mechanisms. However, little is known about the magnitude and fate of methane emissions from shallow submarine sediments to the atmosphere in the peculiar area. In this paper, we present one of the first direct evidences for seepage on the northwestern Barents Sea shelf. By studying the molecular and isotopic signatures of low-molecular-weight hydrocarbons in seawater, near-surface sediment pore space and the sediment matrix at 26 locations, we provide a detailed view on the partitioning of gaseous hydrocarbons in the sediment-water interface off Spitsbergen. In the free gas phase, low concentration of methane (˜28 ng/g wet Sediment) paired with constantly high isotopic values (˜-65‰) is consistent with high impact of methane oxidation on the isotopic composition. In contrast, high concentrations of adsorbed CH4 (up to 5292 ng/g wet sediment matrix suggest that the adsorbed gas is reasonably well protected against microbial degradation. Moreover, the isotopic and molecular signatures of adsorbed CH4 (-38--60‰; ˜100-˜5300 ng/g wet thermally derived hydrocarbon plumes plus in situ adsorbed gas of biological origin. This suggests a minimal exchange and unlike histories of free and adsorbed gas. The majority of gaseous hydrocarbons in the adsorbed pool may be the result of past seepages. Past upward flow of thermogenic gas and impregnation with mature hydrocarbons was particularly strong along tectonic lineaments. Active petroleum source rocks along the continental margin and migration of gaseous hydrocarbons at re-activated fault systems might explain the anomalies along these conduits.

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

2004-06-01

271

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

272

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.)

273

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

274

Methane and sulfur cycling in terrestrial hydrocarbon seeps  

Science.gov (United States)

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

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

2009-12-01

275

NASTRAN migration to UNIX  

Science.gov (United States)

COSMIC/NASTRAN, as it is supported and maintained by COSMIC, runs on four main-frame computers - CDC, VAX, IBM and UNIVAC. COSMIC/NASTRAN on other computers, such as CRAY, AMDAHL, PRIME, CONVEX, etc., is available commercially from a number of third party organizations. All these computers, with their own one-of-a-kind operating systems, make NASTRAN machine dependent. The job control language (JCL), the file management, and the program execution procedure of these computers are vastly different, although 95 percent of NASTRAN source code was written in standard ANSI FORTRAN 77. The advantage of the UNIX operating system is that it has no machine boundary. UNIX is becoming widely used in many workstations, mini's, super-PC's, and even some main-frame computers. NASTRAN for the UNIX operating system is definitely the way to go in the future, and makes NASTRAN available to a host of computers, big and small. Since 1985, many NASTRAN improvements and enhancements were made to conform to the ANSI FORTRAN 77 standards. A major UNIX migration effort was incorporated into COSMIC NASTRAN 1990 release. As a pioneer work for the UNIX environment, a version of COSMIC 89 NASTRAN was officially released in October 1989 for DEC ULTRIX VAXstation 3100 (with VMS extensions). A COSMIC 90 NASTRAN version for DEC ULTRIX DECstation 3100 (with RISC) is planned for April 1990 release. Both workstations are UNIX based computers. The COSMIC 90 NASTRAN will be made available on a TK50 tape for the DEC ULTRIX workstations. Previously in 1988, an 88 NASTRAN version was tested successfully on a SiliconGraphics workstation.

Chan, Gordon C.; Turner, Horace Q.

1990-01-01

276

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

277

SSI, labor supply, and migration  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Neumark, David; Powers, Elizabeth T.

2005-01-01

278

The International-Migration Network  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper studies international migration from a complex-network perspective. We define the international-migration network (IMN) as the weighted-directed graph where nodes are world countries and links account for the stock of migrants originated in a given country and living in another country at a given point in time. We characterize the binary and weighted architecture of the network and its evolution over time in the period 1960-2000. We find that the IMN is organized ...

Fagiolo, Giorgio; Mastrorillo, Marina

2012-01-01

279

21 CFR 178.3530 - Isoparaffinic petroleum hydrocarbons, synthetic.  

Science.gov (United States)

...petroleum hydrocarbons, synthetic. Isoparaffinic petroleum hydrocarbons, synthetic, may be safely used...milliliters maximum. Synthetic isoparaffinic petroleum...Existent Gum in Fuels by Jet Evaporation,”...

2010-04-01

280

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

 
 
 
 
281

European Integration and Labour Migration  

Directory of Open Access Journals (Sweden)

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

Julda Kielyte

2010-11-01

282

Migration and Security of States  

Directory of Open Access Journals (Sweden)

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

Cristian Jura

2012-05-01

283

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)

284

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

285

Isolation and FIMS analysis of saturated hydrocarbons from tar sand bitumens  

Energy Technology Data Exchange (ETDEWEB)

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

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

1986-11-01

286

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

287

Hydrocarbons from ethanol using [Fe,Al]ZSM-5 zeolites obtained by direct synthesis  

Energy Technology Data Exchange (ETDEWEB)

The search for new energy sources has impulsed hydrocarbon production from methanol and ethanol over ZSM-5 zeolites. Iron incorporation by different methods has led to a variety of chemical applications. Thus, hydrocarbon production from ethanol was evaluated using a [Fe,Al]ZSM-5 zeolite which was synthesized without nitrogenated templates, using ethanol and crystallization seeds and partially substituting iron for aluminium in the reaction mixture. Characterization was done by X-ray diffraction (XRD), Fourier-transform infra-red spectroscopy (FTIR), temperature programmed reduction (TPR), temperature programmed desorption of ammonia (TPD), nitrogen adsorption, electron paramagnetic resonance (EPR) and photoacoustic spectroscopies. Iron content in the synthesized samples varied from 0.02 to 1.82%. The obtained samples were used for the ethanol transformation, producing hydrocarbons from ethene to aromatics. Maximum production of liquid hydrocarbons was achieved with the zeolite with 0.5% iron. The procedure for obtaining the acid form of the zeolites, involving ammonium exchange and calcinations, has changed the iron species, probably with extraction from the structure, migration and agglomeration. (author)

Fernandes Machado, Nadia Regina Camargo; Calsavara, Valmir [Departamento de Engenharia Quimica, Universidade Estadual de Maringa, Av. Colombo, 5790, CEP 87020-900, Maringa, Parana (Brazil); Astrath, Nelson Guilherme Castelli; Neto, Antonio Medina; Baesso, Mauro Luciano [Departamento de Fisica, Universidade Estadual de Maringa, Av. Colombo, 5790, CEP 87020-900, Maringa, Parana (Brazil)

2006-09-01

288

Economical recovery of hydrocarbon vapors  

Energy Technology Data Exchange (ETDEWEB)

Up to 90% of the escaping hydrocarbon vapors can be safely and efficiently recovered by means of a new system whose functions are based on the principles of refrigeration and low pressure. These vapors, which are quite valuable when recovered, are generated during the loading of tank cars, tank trucks, and by natural respiration of the storage tanks. Such a system of gasoline vapor recovery was developed by the Southwest Industries (SWI), a subsidiary of Ingersoll Rand Co. THe SWI Unit uses a method of absorption at low temperature, in the place of high pressure absorption, which requires compression of the vapors. Additional benefits for low temperature absorption are listed. This ability to recover these vapors is good news to refiners and petrochemical plant operators, adding considerable revenue to their operations at a reasonable cost and payout time (cost varies from $70,000 to $200,000 for a complete plant, the total cost depending on the number of tanks served).

1972-10-01

289

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.)

290

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

291

Harnessing Migration for Service Export from Sub Saharan Africa: A New Dawn for an Age Old Phenomenon  

Directory of Open Access Journals (Sweden)

Full Text Available Migration issues have enjoyed numerous debates and research in the past two decades. The purpose of thisarticle is to establish the need to re-examine health and education migration to determine if it can be harnessedfor an international service exports. Secondary data is analysed to develop a case for harnessing migration insome sectors from the developing countries. The study throws more light on the migration of health andeducation worker phenomenon by expounding and collating information and puts forward a set of propositionfor a research agenda. From the discussions, questions are developed for a more comprehensive quantitativedata generation. The direction of the study is a clarion call for data that will be the facilitating factor to propelpolicy makers to re-examine migration as an export activity. The study contributes to literature on internationalbusiness specifically migration and international service exports.

Cynthia A. Bulley

2013-10-01

292

New hydrologic model of fluid migration in deep porous media  

Science.gov (United States)

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

Dmitrievsky, A.; Balanyuk, I.

2009-04-01

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

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

295

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

296

The financial losses from the migration of nurses from Malawi  

Directory of Open Access Journals (Sweden)

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

Muula Adamson S

2006-11-01

297

Migration of dendritic cells facilitates systemic dissemination of Burkholderia pseudomallei.  

Science.gov (United States)

Burkholderia pseudomallei, the etiological agent for melioidosis, is an important cause of community-acquired sepsis in northern Australia and northeast Thailand. Due to the rapid dissemination of disease in acute melioidosis, we hypothesized that dendritic cells (DC) could act as a vehicle for dissemination of B. pseudomallei. Therefore, this study investigated the effect of B. pseudomallei infection on DC migration capacity and whether migration of DC enabled transportation of B. pseudomallei from the site of infection. B. pseudomallei stimulated significantly increased migration of bone marrow-derived DC (BMDC), both in vitro and in vivo, compared to uninfected BMDC. Furthermore, migration of BMDC enabled significantly increased in vitro trafficking of B. pseudomallei and in vivo dissemination of B. pseudomallei to secondary lymphoid organs and lungs of C57BL/6 mice. DC within the footpad infection site of C57BL/6 mice also internalized B. pseudomallei and facilitated dissemination. Although DC have previously been shown to kill intracellular B. pseudomallei in vitro, the findings of this study demonstrate that B. pseudomallei-infected DC facilitate the systemic spread of this pathogen. PMID:25069976

Williams, Natasha L; Morris, Jodie L; Rush, Catherine M; Ketheesan, Natkunam

2014-10-01

298

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

299

Secondary cutaneous carcinomatosis  

Directory of Open Access Journals (Sweden)

Full Text Available Secondary cutaneous carcinomatosis may be the primary menifestation of malignancies. Due to the help of modern investigative techniques primary malignant sites can be detected. But in many circumstances the primary site can not be detected in spite of available investigation. The cases presented here clearly show that the secondary cutaneous menifestation may be the first clue for detecting a hidden primary maligmancy.

Kotokey R

1996-01-01

300

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

 
 
 
 
301

Effect of hydratoformation zones, glaciations, and seismicity on the development of hydrocarbon fields  

Energy Technology Data Exchange (ETDEWEB)

Natural factors which determine the rate of generation, migration, and accumulation of oil and gas have been analyzed. The combination of most active factors (glaciations and seismic processes) is shown to favor accumulation of a giant amount of crude and bitumen in Atabask. Accumulation of hydrocarbon bodies and peculiarities of hydrological regime in zones of permanent glacial shields are considered. It is suggested that oil and gas fields are likely to form within the World Ocean - along the margins of lithosphere plates, shelf zones, and mainland slopes of Antarctica. 2 figures, 4 tables.

Trofimuk, A.A.; Cherskii, N.V.; Tsarev, V.P.

1979-04-01

302

Cell migration in confined environments.  

Science.gov (United States)

We describe a protocol for measuring the speed of human neutrophils migrating through small channels, in conditions of mechanical confinement comparable to those experienced by neutrophils migrating through tissues. In such conditions, we find that neutrophils move persistently, at constant speed for tens of minutes, enabling precise measurements at single cells resolution, for large number of cells. The protocol relies on microfluidic devices with small channels in which a solution of chemoattractant and a suspension of isolated neutrophils are loaded in sequence. The migration of neutrophils can be observed for several hours, starting within minutes after loading the neutrophils in the devices. The protocol is divided into four main steps: the fabrication of the microfluidic devices, the separation of neutrophils from whole blood, the preparation of the assay and cell loading, and the analysis of data. We discuss the practical steps for the implementation of the migration assays in biology labs, the adaptation of the protocols to various cell types, including cancer cells, and the supplementary device features required for precise measurements of directionality and persistence during migration. PMID:24560508

Irimia, Daniel

2014-01-01

303

International nurse migrations: Global trends  

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents global trends of migration of nurses, as specific qualified personnel in high demand. In the last couple of decades, and especially in the last couple of years, many countries have faced the problem of insufficient healthcare workers, particularly nurses. Reasons for this occurrence might be found in the deficiencies of their education systems, as well as the population aging of northern and western countries. As a response to this deficiency, those countries have begun intensive recruitment of foreign qualified female healthcare workers, which has led to the point that nurse migration today presents a very intense, and by many accounts specific migration flow. Female migrating work force is often in pursuit of low-wage and lowqualified work. Nurse migration is actually an example of motion of qualified female migrants in pursuit for better employment opportunities. While such a way of filling up the vacant positions works for the “importing” countries as a temporary solution, departure of trained female personnel presents a significant loss for the originating countries. In this paper we pay special attention to the countries who are the main “importers”, but also to those who are “exporters” of nursing personnel, and to specific national strategies these countries have applied.

Ivkovi? Marija

2011-01-01

304

Study of cell kinetics within evolving secondary Haversian systems.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A study of the origin, proliferation rate and migration of cells within the secondary evolving Haversian systems was undertaken in young adult Beagle dogs. Autoradiographs of serial longitudinal sections prepared from rib biopsies taken from one hour to eleven days after the injection of tritiated thymidine were subjected to semiquantitative analysis as to the time of appearance, number, location and transformation of various labelled cells. Numerous labelled osteoblasts appeared early (at 14...

Jaworski, Z. F.; Hooper, C.

1980-01-01

305

Selective photooxidation of hydrocarbons in zeolites by oxygen  

Science.gov (United States)

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

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

1998-01-01

306

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

307

Migrating lumbar facet joint cysts  

International Nuclear Information System (INIS)

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

308

Brownian Motion in Planetary Migration  

CERN Document Server

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

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

2006-01-01

309

The International-Migration Network  

CERN Document Server

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

Fagiolo, Giorgio

2012-01-01

310

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2010-07-01

311

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

312

Using microorganisms to aid in hydrocarbon degradation  

Energy Technology Data Exchange (ETDEWEB)

Aliphatic hydrocarbons are threatening the potable water supply and the aquatic ecosystem. Given the right microbial inhabitant(s), a large portion of these aliphatic hydrocarbons could be biodegraded before reaching the water supply. The authors' purpose is to isolate possible oil-degrading organisms. Soil samples were taken from hydrocarbon-laden soils at petroleum terminals, a petroleum refinery waste-treatment facility, a sewage-treatment plant grease collector, a site of previous bioremediation, and various other places. Some isolates known to be good degraders were obtained from culture collection services. These samples were plated on a 10w-30 multigrade motor oil solid medium to screen for aliphatic hydrocarbon degraders. The degrading organisms were isolated, identified, and tested (CO[sub 2] evolution, BOD, and COD) to determine the most efficient degrader(s). Thirty-seven organisms were tested, and the most efficient degraders were Serratia marcescens, Escherichia coli, and Enterobacter agglomerans.

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

1993-04-01

313

Hydrocarbon solvents in high solids coatings  

Energy Technology Data Exchange (ETDEWEB)

In 1976, the Environmental Protection Agency (EPA) adopted a new approach to regulating emissions from coatings - to limit emissions regardless of chemical type. As a result, aromatic hydrocarbon solvents again can be incorporated into coatings when they provide performance and cost benefits. In this paper, alkyd and polyester high solids coatings formulated with a combination of aromatic hydrocarbon and oxygenated solvents are compared to the same coatings formulated only with oxygenated solvents. The properties investigated were solubility, volatile organic compound (VOC) content, viscosity, rheology, sprayability, and final film properties. To supplement the laboratory tests, a high solids alkyd baking enamel containing aromatic hydrocarbon solvent was evaluated in two commercial plant trials. It performed well. In summary, substituting hydrocarbon solvent for some of the oxygenated solvent reduced the viscosity and volatile organic compound content of the high solids coatings without compromising performance. The substitution also substantially reduces cost: Aromatic solvents cost about $2.00 per gallon less than the oxygenated solvents they replace.

Albaugh, E.W.; Chiozza, R.F.; Pecoraro, J.M.

1987-11-01

314

Stable isotope investigations of chlorinated aliphatic hydrocarbons.  

Science.gov (United States)

Stable isotope ratio measurements for carbon (C) and chlorine (Cl) can be used to elucidate the processes affecting transformation and transportation of chlorinated aliphatic hydrocarbons (CAHs) in the environment. Methods recently developed in our labora...

T. Abrajano, L. J. Heraty, B. D. Holt, L. Huang, N. C. Sturchio

1999-01-01

315

MICROEMULSION FORMATION WITH MIXED CHLORINATED HYDROCARBON LIQUIDS  

Science.gov (United States)

Mixing rules for water/chlorocarbon/anionic-surfactant systems have been studied. t was found that the behavior of chlorocarbons parallels the ideal mixing rules for hydrocarbons. he polarity of some chlorocarbons prevented a direct determination of electrolyte concentration and ...

316

BIOREMEDIATED SOIL VENTING OF LIGHT HYDROCARBONS  

Science.gov (United States)

The effectiveness and feasibility of bioremediated soil venting of light hydrocarbons in the unsaturated zone was investigated. Degradation mechanics were considered as a one dimensional balance of storage, linear sorption, vertical advection, and Michaelis-Menton kinetics. he re...

317

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)

318

Using microorganisms to aid in hydrocarbon degradation  

International Nuclear Information System (INIS)

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

319

METHODOLOGY FOR ESTIMATING NATURAL HYDROCARBON EMISSIONS  

Science.gov (United States)

An emission inventory system for biogenic sources of hydrocarbons has been developed. It is based on modifications of the classic formula: Emissions = Sigma Biomass Area Emission Factor. It accommodates multiple sources with emission factors dependent on season, temperature and s...

320

Enhanced natural attenuation of hydrocarbon contaminated land  

...FAQsAccess KeysEnhanced natural attenuation of hydrocarbon contaminated landLast updated: 30...which leads to initiation and acceleration of natural attenuation through the addition of the rate limiting nutrients...

 
 
 
 
321

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

322

Individuals' openness to migrate and job mobility.  

Science.gov (United States)

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

Huinink, Johannes; Vidal, Sergi; Kley, Stefanie

2014-03-01

323

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

324

Retirement migration and military retirement  

International Nuclear Information System (INIS)

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

325

International Migration, Remittances and Development  

Directory of Open Access Journals (Sweden)

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

Hasan Mahmud

2009-02-01

326

Arctic thermogenic gas-hydrate provinces fuelled by deep-hydrocarbon venting  

Science.gov (United States)

Arctic submarine gas hydrates may receive thermogenic gas through leakage systems from hydrocarbon provinces. Our research concentrates on high latitudes in a region where the on average 300 m deep Barents Sea covers an area of about 1.3 million km2. Since the greatest gas discovery in the Norwegian economic zone so far (Snøhvit in 1984), the petroleum industry requested several 3D seismic surveys to be carried out in the area in addition to 2D seismic lines. The data allow an assessment of fluid flow from a gas reservoir to the gas hydrate stability zone. The two main objectives are: a) detecting where and how fluids migrate from greater depth to the seabed and 2) identifying shallow acoustic anomalies and their relationship to fluid migration pathways. We will show that fluids are migrating through the whole stratigraphic column to the seafloor but that they are also trapped in specific horizons as for example the gas hydrate stability zone. The geophysically inferred fluid migration occurs over a vertical distance of ~ 1700 m where the time involved remains unknown. At the seafloor, pockmarks or seabed craters exists depending on the dynamics of the involved processes. Fluids and gas that reach the seafloor can rapidly escape to the hydrosphere and, because of the shallow water depth, may contribute to greenhouse gas concentrations in the atmosphere. The total volumes of gas that may leave the chimneys are unknown but may be of importance in terms of glacial-interglacial methane cycles. The Barents Sea area may have experienced significant cycles of fluid expulsion and natural hydrocarbon leakage due to major episodes of sediment erosion and pressure changes driven by ice ages.

Mienert, J.; Bünz, S.; Thingnes, V.; Chand, S.

2009-04-01

327

Hydrocarbon Degrading Bacteria: Isolation and Identification  

Digital Repository Infrastructure Vision for European Research (DRIVER)

There is little information how to identify hydrocarbon degrading bacteria for bioremediation of marine oil spills. We have used gravel which contaminated oil mousse from Beach Simulator Tank, in Marine Biotechnology Institute, Kamaishi, Japan, and grown on enrichment culture. Biostimulation with nutrients (N and P) was done to analyze biodegradation of hydrocarbon compounds: Naphthalene, Phenanthrene, Trichlorodibenzofuran and Benzo[a]pyrene. Community of bacteria from enrichment culture was...

Lies Indah Sutiknowati

2007-01-01

328

Acquired and Innate Immunity to Polyaromatic Hydrocarbons  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

2007-01-01

329

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

330

Laser spectroscopy of hydrocarbon radicals  

Energy Technology Data Exchange (ETDEWEB)

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

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

1993-12-01

331

Secondary syphilis and HIV  

Science.gov (United States)

Syphilis has been termed the “great mimic” due to its versatile and varied disease presentations. Dermatological findings are associated with the secondary phase of the disease and typically consist of a generalized papular eruption that can involve the palms and soles, genitals, and mucous membranes. Patients with syphilis and concomitant HIV infection may have altered presentations. We report a case of a 41-year-old HIV-positive man who presented with a papular rash of a few months' duration and was diagnosed with secondary syphilis. PMID:22275795

Dhaliwal, Shagun; Patel, Mahir

2012-01-01

332

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

333

Long migration flights of birds  

Science.gov (United States)

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

Denny, Mark

2014-05-01

334

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

335

Analysis of antidune migration direction  

Science.gov (United States)

Antidunes are bed forms characteristic of upper regime unidirectional flows. Contrary to bed forms developed in lower regime flows, antidunes not only can propagate in the downstream direction but can propagate upstream or remain stationary. In this work we analyze the stable hydraulic conditions that determine each of the three antidune movement possibilities, and a new theory is developed for distinguishing the occurrence of each of these conditions. The theory is developed from an energy balance over a symmetrical antidune; for this, the Bernoulli equation is applied between the antidune crest and antidune trough, and the pressure head is corrected to account for the centrifugal forces generated by curvilinear flow. Manipulation of the fundamental equations produces an antidune mobility dimensionless number (Fa), dependent on the Froude number, the mean water depth, and the antidune wavelength. The critical value of the antidune mobility number (Fa = 1) corresponds to the stationary condition, while values higher and lower than the critical correspond to downstream and upstream propagation, respectively. Theory predicts that for a given Froude number, downstream-migrating antidunes are formed for higher water depth-wavelength ratios than for upstream-migrating antidunes. Likewise, by introducing a restriction for the maximum stationary wave height above antidunes, theory predicts that downstream-migrating antidunes could attain steeper height-wavelength ratios than upstream-migrating antidunes. Comparison with published experimental data in literature largely showed agreement between theory and experimental observations.

NúñEz-GonzáLez, Francisco; MartíN-Vide, Juan P.

2011-06-01

336

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

337

Sooting tendencies of oxygenated hydrocarbons in laboratory-scale flames.  

Science.gov (United States)

Sooting tendencies have been measured for 186 oxygenated and 89 regular hydrocarbons under controlled laboratory conditions. The test compounds include alcohols, ethers, aldehydes, ketones, esters, alkanes, alkenes, and cycloalkanes ranging in size from methanol to isododecane. Sooting tendency was characterized with a new method based on measuring particle concentrations in methane/air nonpremixed flames when 1000 ppm of each test compound was added to the fuel. This method offers high precision and high sensitivity to the direct chemical effects of the additive. The results provide a wide-ranging yet detailed quantitative picture of how fuel oxygen affects soot formation, which will be useful for optimizing the soot-reducing benefits of oxygenated renewable fuels. The measured sooting tendencies of 1-alcohols are similar to those of n-alkanes with the same number of carbon atoms, while those of secondary alcohols are slightly higher. Aldehydes and ketones soot the same as n-alkanes with one less carbon atom. The sooting tendencies of esters depend strongly on molecular structure and increase in this order: methyl and ethyl esters < carboxylic acids, propyl esters, and n-alkanes < butyl and pentyl esters. The high sooting tendencies of the secondary alcohols and higher esters suggest that four-center and six-center reaction pathways are important. PMID:21329344

McEnally, Charles S; Pfefferle, Lisa D

2011-03-15

338

[Haitian migration to Santo Domingo].  

Science.gov (United States)

This work examines the history of Haitian migration to the Dominican Republic, the central role of Haitian migration in Dominican society, working conditions of Haitian migrants in the Dominican Republic, and the relationship of the migration to economic development on the island of Hispaniola. Lack of data, the difficulty of measuring illegal movement, and the problem of defining Haitians in Santo Domingo have impeded understanding of migration to the Dominican Republic. It is believed by many authorities that Haitian migration to Santo Domingo is considerable and perhaps exceeds that to the US. Haitian migration to the Dominican Republic began after 1915 with the fall of the Haitian president, a worsening of economic conditions partly caused by stagnation in the agricultural sector, and the newly dominant role of the US in Haitian economic affairs. The Great Depression of the 1930s was a direct antecedent of the massacre of Haitians by Dominican police in which some 30 thousand persons were killed; the economic recession of the early 1980s has also caused an outburst of antiHaitian feeling in the Dominican Republic although 80% of laborers in the sugar industry are Haitians. Sugar is extremely important to the Dominican economy: in 1974, sugar covered 12% of cultivated land, produced 40% of foreign exchange earnings, and was responsable for 21% of taxable income. Dominicans however refuse to work in sugar plantations under the current technological. conditions and wage system. Although the government periodically demands the Dominicanization of the sugar work force, no such changes have been made. Sugar will probably continue to play a decisive role in the generation of foreign exchange despite introduction of more technologically advanced sectors which benefit from better prices in the international market. Possibilities of mechanizing sugar production in the Dominican Republic appear remote, and failure to modernize an important sector of the economy has explained migration of unskilled labor from poorer countries in more than 1 case. Under such circumstances, the extremely poor working conditions of Haitians in the Dominican Republic are not surprising. A 1983 investigation by the International Labour Organization indicated that salaries were low, that a large proportion was routinely diverted from the migrants, that hours of work were long with no regular rest and few days off, that few workers had any contractual protection, that forced labor recruitment occurred, that a rigid system of vigilance with armed patrols was used to keep the immigrants in the work camps, and that living conditions were substandard--in short, that Haitian workers were "neo-slaves". In addition, the Dominicans consider themselves racially and culturally superior to Haitians. The Haitian government, in return for payments from the Dominican Republic, does nothing to stop the abuses. PMID:12179414

Latortue, P R

1985-01-01

339

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

340

On the Radiolysis of Ethylene Ices by Energetic Electrons and Implications to the Extraterrestrial Hydrocarbon Chemistry  

Science.gov (United States)

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

Zhou, Li; Maity, Surajit; Abplanalp, Matt; Turner, Andrew; Kaiser, Ralf I.

2014-07-01

 
 
 
 
341

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

342

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

343

[Migration patterns of health professionals].  

Science.gov (United States)

The past three decades have seen the number of international migrants double, to reach the unprecedented total of 175 million people in 2003. National health systems are often the biggest national employer, responsible for an estimated 35 million workers worldwide. Health professionals are part of the expanding global labour market. Today, foreign-educated health professionals represent more than a quarter of the medical and nursing workforces of Australia, Canada, the United Kingdom and the United States. Destination countries, however, are not limited to industrialised nations. For example, 50 per cent of physicians in the Namibia public services are expatriates and South Africa continues to recruit close to 80% of its rural physicians from other countries. International migration often imitates patterns of internal migration. The exodus from rural to urban areas, from lower to higher income urban neighbourhoods and from lower-income to higher-income sectors contributes challenges to the universal coverage of the population. International migration is often blamed for the dramatic health professional shortages witnessed in the developing countries. A recent OECD study, however, concludes that many registered nurses in South Africa (far exceeding the number that emigrate) are either inactive or unemployed. These dire situations constitute a modern paradox which is for the most part ignored. Shared language, promises of a better quality of life and globalization all support the continued existence of health professionals' international migration. The ethical dimension o this mobility is a sensitive issue that needs to be addressed. A major paradigm shift, however, is required in order to lessen the need to migrate rather than artificially curb the flows. PMID:16285406

Kingma, Mireille

2005-01-01

344

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

345

Hydrocarbon separation with a physical solvent  

Energy Technology Data Exchange (ETDEWEB)

This patent describes a continuous process for producing a liquid hydrocarbon product of a selected composition, which is selectively adjustable to substantially any selected degree in accordance with market conditions, and a residue natural gas stream of pipeline quality that selectively includes ethane (C/sub 2/), propane (C/sub 3/), and butanes (C/sub 4/) by extraction of an inlet natural gas stream, containing at least 0.2 mol percent of C/sub 5/+ hydrocarbons, with a stream of a physical solvent, the improvement described here consists of minimizing the energy required for the process while recovering up to 100% of the C/sub 5/+ hydrocarbons in accordance with the market conditions by the following steps: A. selectively extracting the inlet natural gas stream in a first extraction stage with a major solvent stream and in a second extraction stage with a minor solvent stream, the major solvent stream containing up to an equilibrium amount of C/sub 5/+ hydrocarbons and the minor solvent stream being lean with respect to C/sub 1/+ hydrocarbons, whereby a rich solvent stream and a residue natural gas stream are produced, the residue natural gas stream containing selected maximum amounts of C/sub 2/+ hydrocarbons in accordance with the market conditions; B. successively flashing the rich solvent stream in a plurality of flashing stages at pressures that successively decrease to about atmospheric pressure in order to produce successive C/sub 1/+ gas fractions, having successively lower methane contents, and flashed solvent streams containing the solvent and hydrocarbons having successively lower methane contents, the flashing pressures of the successive flashing stages being selectively varied; C. dividing the physical solvent stream into the major solvent stream and a slipstream; and D. regenerating the slipstream in order to produce the minor solvent stream for the second extraction stage.

Mehra, Y.R.

1986-03-25

346

Volatile hydrocarbons inhibit methanogenic crude oil degradation  

Science.gov (United States)

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

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

2014-01-01

347

Suicide among Secondary Students.  

Science.gov (United States)

Investigated incidence of adolescent suicide in Kansas and assessed prevention guidelines and services dealing with adolescent suicide, and perceived needs of Kansas secondary school counselors in the area of teenage suicide. Findings from 484 school counselors indicated increase in suicide rates with age and need for suicide prevention programing…

Coder, Tamara L.; And Others

1991-01-01

348

Secondary Dance Instructional Guide.  

Science.gov (United States)

This manual provides guidelines for dance teachers in secondary schools. A brief statement is made on the purpose and philosophy of dance education, and activities and instructional suggestions are presented for various dance forms: (1) group dance--folk/ethnic, square dance, and social dance; (2) aerobic dance; (3) jazz dance; (4) modern dance;…

Montgomery County Public Schools, Rockville, MD. Dept. of Instructional Planning and Development.

349

Migration of shallow marine seismic data  

Energy Technology Data Exchange (ETDEWEB)

I applied the f-k migration using the phase shift method in the frequency domain to shallow marine seismic data. I tested a simple model which has different dips and velocities to analyze the migration effect. I used different velocities for the migration of the shallow marine seismic data acquired off Pohang and estimated the horizontal and vertical movement assuming a velocity and measuring the dip angle and two-way travel time from the folding structure in the seismic section. Proper migration velocity was determined not to over migrate. The migration effect of dip structure was small, even if the dip looks steep in the seismic section because the dip was exaggerated vertically. The migration of complex structure was conducted successfully. The diffraction was removed well and the irregular boundary and structure below the boundary appeared clearly after migration. (author). 9 refs., 9 figs.

Lee, Ho Young [Korea Institute of Geology Mining and Materials, Taejon (Korea, Republic of)

1996-06-30

350

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

Science.gov (United States)

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

Weber, A; Hörmann, G

2011-05-01

351

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2005-07-01

352

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

353

American Indian Migration and Economic Opportunities.  

Science.gov (United States)

Explores the determinants of interstate migration and the impact of migration on labor force participation for American Indians, in comparison to White and intermarried Indian/White couples. Interstate migration was much lower for endogenous American Indian couples, but its effect on labor force participation was the same for all couples. (ETS)

Sandefur, Gary D.

1986-01-01

354

Migration on Wings Aerodynamics and Energetics  

CERN Document Server

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

Kantha, Lakshmi

2012-01-01

355

Juridical structures: refugees and migration.  

Science.gov (United States)

The juridical problems in regard to the concepts of refugee, expulsion, and migration are complicated. If one speaks about migration in Europe, one must 1st distinguish between Eastern and Western Europe. In the communist states of Eastern Europe the refugee problem does not exist officially, with the only existing refugee problem in Yugoslavia, which has signed and ratified the Geneva Refugee Convention of 1951. In the other East European states the right to asylum exists, but refugees are granted asylum only if they are persecuted in their country of origin for their communist ideas and activities. In speaking of migration, one must distinguish between migration, forced migration, mass migration, emigration, immigration, the shift of populations, and refugees. In the communist countries of Eastern Europe the right to emigration is not respected, although certain exceptions, as in Poland or Yugoslavia do exist. Generally, in the communist states emigration is not allowed and illegal emigration is punished as "Flight from the Republic." With a few exceptions, political and other persecutions are no longer so typical within Europe. In the last decades, the refugee problem has changed to other continents: Afghanistan/Pakistan, Iran, Sri Lanka, East Timor, Lebanon, Palestine, Sudan, Tchad, Ethiopia, Eritrea, and Angola. The refugee problem in Europe consists mainly in the large afflux of refugees coming from places with other cultural (and religious) attributes. The Islamic immigrants declare themselves regularly as political refugees and hope to be acknowledged as such by the receiving state. The fear of the governments and populations of the receiving countries is that it would not be possible to assimilate such aliens who do not belong to the Christian culture of Europe. Formerly, refugees came mostly from the Christian countries of Eastern Europe with the same race identity and the same religion. For years now, more and more foreign workers are a kind of migrant within the European Economic Community, and now total about 14 million. Within international public law, there exists the principle of non-refoulement which protects a refugee (and also an asylum-seeker not recognized as a refugee) against expulsion or return, in any manner whatsoever, to a territory where his life or freedom would be threatened on account of his race, nationality, religion, or membership in a particular social group or political opinion. PMID:12281755

Veiter, T

1988-01-01

356

Syngas Upgrading to Hydrocarbon Fuels Technology Pathway  

Energy Technology Data Exchange (ETDEWEB)

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

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

2013-03-31

357

Hydrogenative decomposition device for hydrocarbon oil  

International Nuclear Information System (INIS)

The vessel for decomposition according to the present invention comprises a water decomposition vessel disposed around a storage portion of a radioactive material container to which water for decomposition is injected, a gas separation column for separating hydrogen gas generated by decomposition of water, and a reaction vessel having a gas mixture fluid of hydrocarbon oil and hydrogen gas disposed around the storage portion, and from which hydrocarbon product is taken out. Radiation rays from radioactive materials stored in both of the water decomposition vessel and the reaction vessel are absorbed by water and hydrocarbon oil at the periphery thereof. Water is partially decomposed into oxygen gas and hydrogen gas by irradiation of radiation rays, and hydrogen gas is separated and sent to the reaction vessel. A portion of molecular chains of the hydrocarbon oil is splitted by irradiation of radiation rays to reduce molecular weight, and hydrocarbon products in a stable state are obtained by hydrogenation. Hydrogen is formed using radioactive wastes as an energy source and the quality of heavy crude oils can be improved. (T.M.)

358

Impact craters: implications for basement hydrocarbon production  

Energy Technology Data Exchange (ETDEWEB)

The impact cratering process results in unique structures and extensive fracturing and brecciation of the target rock which can be conducive to hydrocarbon accumulations. Examination of Viewfield and Red Wing Creek oil pools in North America reveals that they may have been formed by meteoritic impact in Paleozoic sediments. Additional hydrocarbon traps have most likely been produced by impact but have not been recognized as such because geologists are generally not familiar with crater structures and shock-metamorphic effects in rocks. It is proposed that petroliferous basement impact craters also exist and that despite arguments to the contrary, at least one may have already been found. Further discoveries are severely limited because of conservative exploration procedures, which characteristically avoid penetrating crystalline basement. Core analysis from several large impact sites developed in crystalline rocks reveals that while permeability factors are marginal, the reservoir potential of these craters exceeds those of many of the largest known hydrocarbon accumulations. Preservation age studies of craters in conjunction with size frequency distribution curves implies that many will have been buried before erosional eradication. As with normally-fractured and brecciated basement areas, some will have accumulated hydrocarbons. In addition to classical source rocks flanking or overlying these potential reservoirs, recycled kerogen and the possibility of inorganic sources are also considered. A basement impact crater may afford a unique way of testing the inorganic hydrocarbon proposals.

Donofrio, R.R.

1981-01-01

359

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

International Nuclear Information System (INIS)

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

360

Paleozoic Hydrocarbon-Seep Limestones  

Science.gov (United States)

To date, five Paleozoic hydrocarbon-seep limestones have been recognized based on carbonate fabrics, associated fauna, and stable carbon isotopes. These are the Middle Devonian Hollard Mound from the Antiatlas of Morocco [1], Late Devonian limestone lenses with the dimerelloid brachiopod Dzieduszyckia from the Western Meseta of Morocco [2], Middle Mississippian limestones with the dimerelloid brachiopod Ibergirhynchia from the Harz Mountains of Germany [3], Early Pennsylvanian limestones from the Tantes Mound in the High Pyrenees of France [4], and Late Pennsylvanian limestone lenses from the Ganigobis Shale Member of southern Namibia [5]. Among these examples, the composition of seepage fluids varied substantially as inferred from delta C-13 values of early diagenetic carbonate phases. Delta C-13 values as low as -50 per mil from the Tantes Mound and -51 per mil from the Ganigobis limestones reveal seepage of biogenic methane, whereas values of -12 per mil from limestones with Dzieduszyckia associated with abundant pyrobitumen agree with oil seepage. Intermediate delta C-13 values of carbonate cements from the Hollard Mound and Ibergirhynchia deposits probably reflect seepage of thermogenic methane. It is presently very difficult to assess the faunal evolution at seeps in the Paleozoic based on the limited number of examples. Two of the known seeps were typified by extremely abundant rhynchonellide brachiopods of the superfamily Dimerelloidea. Bivalve mollusks and tubeworms were abundant at two of the known Paleozoic seep sites; one was dominated by bivalve mollusks (Hollard Mound, Middle Devonian), another was dominated by tubeworms (Ganigobis Shale Member, Late Pennsylvanian). The tubeworms from these two deposits are interpreted to represent vestimentiferan worms, based on studies of the taphonomy of modern vestimentiferans. However, this interpretation is in conflict with the estimated evolutionary age of vestimentiferans based on molecular clock methods, which suggest a maximal age of 126 million years for this group. 1. Peckmann et al. (1999) Facies 40, 281. 2. Peckmann et al. (2007) Palaios 22, 114. 3. Peckmann et al. (2001) Geology 29, 271. 4. Buggisch and Krumm (2005) Facies 51, 566. 5. Himmler et al. (submitted) Palaeogeogr., Palaeoclimatol., Palaeoecol.

Peckmann, J.

2007-12-01

 
 
 
 
361

Hydrocarbons in carbonate rocks of the Neoproterozoic Alto Paraguay basin, Mato Grosso, Brazil  

Energy Technology Data Exchange (ETDEWEB)

Full text of publication follows: A singular occurrence of hydrocarbons (bitumen) was found in Neo proterozoic carbonate rocks of the Araras Formation (Alto Paraguay basin) in the Terconi quarry (Mirassol d'Oeste, Mato Grosso, Brazil). The bitumen occurs in a transgressive carbonate succession overlying Varanger tillites, that consists of two facies associations: (1) lagoon complex, with pink parallel-laminated dolomicrites and fenestral stromatolitic biostromite, and (2) tidal-flat complex, represented by terrigenous gray micrites and pseudosparites, with parallel lamination, asymmetric ripple marks, tepee breccia, planar stromatolites and evaporites. When fresh, the bitumen is compact and vitreous, filling fractures, stylolites and dissolution cavities, generally associated with calcite cement and euhedral dolomite crystals. Microscopic examination shows the bitumen filling pores of primary (fenestral) and secondary (moldic and intragranular) origins. As the first record of hydrocarbon in Neoproterozoic rocks of the Paraguay Belt, this occurrence opens a new perspective for the evaluation of oil potential in Precambrian rocks of Central Brazil. (author)

Nogueira, Afonso C.R. [Fundacao Univ. do Amazonas, Manaus (Brazil). Dept. de Geociencias; Kerkis, Alexei; Hidalgo, Renata L. [Sao Paulo Univ., SP (Brazil). Inst. de Geociencias. Programa de Pos-graduacao em Geologia Sedimentar; Riccomini, Claudio; Fairchild, Thomas R. [Sao Paulo Univ., SP (Brazil). Inst. de Geociencias]. E-mail: acrnogue@usp.br

2001-09-01

362

Modeling of the 2007 JET ^13C migration experiments  

Science.gov (United States)

Using the last run day of the 2007 JET experimental campaign, ^13CH4 was introduced repeatedly from the vessel top into a single plasma type (H-mode, Ip= 1.6 MA, Bt= 1.6 T). Similar experiments were performed in 2001 (vessel top into L-Mode) and 2004 (outer divertor into H-Mode). Divertor and wall tiles were removed and been analysed using secondary ion mass spectrometry (SIMS) and Rutherford backscattering (RBS) to determine the ^13C migration. ^13C was observed to migrate both to the inner (largest deposit), outer divertor (less) , and the floor tiles (least). This paper reports the EDGE2D/NIMBUS based modelling of the carbon migration. The emphasis is on the comparison of the 2007 results with the 2001 results where both injections were from the machine top but ELMs were present in 2007 but not present in 2001. The ELMs seemed to cause more ^13C re-erosion near the inner strike point. Also of interest is the difference in the Private Flux Region deposits where the changes in divertor geometry between 2004 and 2007 caused differences in the deposits. In 2007, the tilting of the load bearing tile caused regions of the PFR to be shadowed from the inner strike point which were not shadowed in 2004, indicating ^13C neutrals originated from the OSP.

Strachan, J. D.; Likonen, J.; Hakola, A.; Coad, J. P.; Widdowson, A.; Koivuranta, S.; Hole, D. E.; Rubel, M.

2010-11-01

363

The Economic Crisis and Labour Migration Policy in European Countries  

Directory of Open Access Journals (Sweden)

Full Text Available This paper reviews changes in migration policies as a response to the 2008 financial and economic crisis and examines issues of migration governance. Countries in Europe opted to make new immigration more difficult, protected their labour markets for native born workers, encouraged the return of migrant workers and intensified efforts to curb irregular migration. Clear patterns or reasons for variation in policy responses are not discernible, but it is safe to say that only countries with a significant recent influx of migrants have taken high profile measures at all. The crisis has led to a shift in perspective of the State and its role in economics which is now seen as useful instead of undesired. Previously prevailing neo-liberal thought relegated the State to the “high politics” of sovereignty and security issues. The crisis has highlighted labour market issues, and migrants are now increasingly portrayed as economic agents instead of security threats. This offers room for the State to assert its protective role vis-à-vis migrant workers – a welcome development. The analysis has an International Relations/Political Economy perspective and is largely based on (official news releases and secondary sources.

Christiane Kuptsch

2012-08-01

364

Vortex migration in protoplanetary discs  

Directory of Open Access Journals (Sweden)

Full Text Available Vortices embedded in protoplanetary discs can act as obstacles to the unperturbed disc flow. The resulting velocity perturbations propagate away from the vortex in the form of density waves that transport angular momentum. Any asymmetry between the inner and the outer density wave means that the region around the vortex has to change its angular momentum. We find that this leads to orbital migration of the vortex. Asymmetric waves always arise except in the case of a disc with constant pressure, for isothermal as well as non-isothermal discs. Depending on the size and strength of the vortex, the resulting migration time scales can be as short as a few thousand orbits.

Papaloizou John C. B.

2013-04-01

365

Physicists' Forced Migrations under Hitler  

Science.gov (United States)

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

Beyerchen, Alan

2011-03-01

366

MIGRATION OF ORACLE HR DATABASE  

CERN Document Server

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

ais.support@cern.ch

2001-01-01

367

Monomer Migration and Annihilation Processes  

International Nuclear Information System (INIS)

We propose a two-species monomer migration-annihilation model, in which monomer migration reactions occur between any two aggregates of the same species and monomer annihilation reactions occur between two different species. Based on the mean-field rate equations, we investigate the evolution behaviors of the processes. For the case with an annihilation rate kernel proportional to the sizes of the reactants, the aggregation size distribution of either species approaches the modified scaling form in the symmetrical initial case, while for the asymmetrical initial case the heavy species with a large initial data scales according to the conventional form and the light one does not scale. Moreover, at most one species can survive finally. For the case with a constant annihilation rate kernel, both species may scale according to the conventional scaling law in the symmetrical case and survive together at the end.

368

Nuclide-migration field experiments  

International Nuclear Information System (INIS)

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

369

Algebraic Kekulé formulas for benzenoid hydrocarbons.  

Science.gov (United States)

By assigning two pi-electrons of CC double bonds in a Kekulé valence structure to a benzene ring if not shared by adjacent rings and one pi-electron if CC double bond is shared by two rings we arrived at numerical valence formulas for benzenoid hydrocarbons. We refer to numerical Kekulé formulas as algebraic Kekulé valence formulas to contrast them to the traditional geometrical Kekulé valences formulas. The average over all numerical Kekulé valence structures results in a single numerical structure when a benzenoid hydrocarbon molecule is considered. By ignoring numerical values the novel quantitative formula transforms into a qualitative one which can replace incorrectly used notation of pi-electron sextets to indicate aromatic benzenoids by placing inscribed circles in adjacent rings-which contradicts Clar's characterization of benzenoid hydrocarbons. PMID:15032513

Randi?, Milan

2004-01-01

370

Hydrocarbon Degrading Bacteria: Isolation and Identification  

Directory of Open Access Journals (Sweden)

Full Text Available There is little information how to identify hydrocarbon degrading bacteria for bioremediation of marine oil spills. We have used gravel which contaminated oil mousse from Beach Simulator Tank, in Marine Biotechnology Institute, Kamaishi, Japan, and grown on enrichment culture. Biostimulation with nutrients (N and P was done to analyze biodegradation of hydrocarbon compounds: Naphthalene, Phenanthrene, Trichlorodibenzofuran and Benzo[a]pyrene. Community of bacteria from enrichment culture was determined by DGGE. Isolating and screening the bacteria on inorganic medium contain hydrocarbon compounds and determination of bacteria by DAPI (number of cells and CFU. DNA was extracted from colonies of bacteria and sequence determination of the 16S rDNA was amplified by primers U515f and U1492r. Twenty nine strains had been sequence and have similarity about 90-99% to their closest taxa by homology Blast search and few of them have suspected as new species.

Lies Indah Sutiknowati

2007-11-01

371

Graphane: a two-dimensional hydrocarbon  

CERN Document Server

We predict the stability of a new extended two-dimensional hydrocarbon on the basis of first-principles total energy calculations. The compound that we call graphane is a fully saturated hydrocarbon derived from a single graphene sheet with formula CH. All of the carbon atoms are in sp3 hybridization forming a hexagonal network and the hydrogen atoms are bonded to carbon on both sides of the plane in an alternating manner. Graphane is predicted to be stable with a binding energy comparable to other hydrocarbons such as benzene, cyclohexane, and polyethylene. We discuss possible routes for synthesizing graphane and potential applications as a hydrogen storage material and in two dimensional electronics.

Sofo, J O; Barber, G D; Sofo, Jorge O.; Chaudhari, Ajay S.; Barber, Greg D.

2006-01-01

372

Migration et genre au Sénégal  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Les rapports de genre dans la migration sénégalaise connaissent une évolution notable depuis une trentaine d’années, marquées par la croissance de la présence féminine dans les mouvements internationaux de personnes. Dans les milieux de départ, les mutations socioculturelles s’affirment tant en milieu urbain que rural, et les difficultés économiques sont de plus en plus aiguës. Dans les pays de destination, les conditions d’installation deviennent sans cesse plus contraignant...

Sakho, Papa; Diop, Rosalie A.; Awissi-sall, Madon

2011-01-01

373

Agglomeration, Migration and Tax Competition  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper focuses on tax competition and international migration in R&D sectors as agglomeration forces and trade restrictions are present. Economic integration forces industrialized countries to adapt their tax rates in order to keep their industrial status quo. Unlike the often discussed "race to the bottom" result, taxes are increased and the provision of public goods is maintained. It is also proven that taxes that redistribute between mobile and immobile labor lead to a tax burden that ...

Hafner, Kurt A.

2005-01-01

374

Incentives and disincentives: international migration.  

Science.gov (United States)

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

Bhagwati, J N

1984-01-01

375

Lymphocyte migration and radiation lymphopenia  

International Nuclear Information System (INIS)

The dose received by suppressor and helper T lymphocyte suppopulations during a course of pelvic radiation therapy is calculated, taking into account variances in the migration pattern of the two cell types. It is found that the difference in the calculated dose may explain the apparent paradox that the cell type, which is found to be more radioresistant in vitro, is more depleted by the in vivo irradiation

376

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

2010-01-01

377

Self-selection patterns in Mexico-U.S. migration: the role of migration networks  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper examines the role of migration networks in determining self-selection patterns of Mexico-U.S. migration. We first present a simple theoretical framework showing how such networks impact on migration incentives at different education levels and, consequently, how they are likely to affect the expected skill composition of migration. Using survey data from Mexico, we then show that the probability of migration is increasing with education in communities with low migran...

Mckenzie, D.; Rapoport, H.

2007-01-01

378

Transplantation stimulates interstitial cell migration in hydra  

International Nuclear Information System (INIS)

Migration of interstitial cells and nerve cell precursors was analyzed in Hydra magnipapillata and Hydra vulgaris (formerly Hydra attenuata). Axial grafts were made between [3H]thymidine-labeled donor and unlabeled host tissue. Migration of labeled cells into the unlabeled half was followed for 4 days. The results indicate that the rate of migration was initially high and then slowed on Days 2-4. Regrafting fresh donor tissue on Days 2-4 maintained high levels of migration. Thus, migration appears to be stimulated by the grafting procedure itself

379

Water and contaminant movement: migration barriers  

International Nuclear Information System (INIS)

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

380

Monopulse secondary surveillance radar  

Science.gov (United States)

A new generation of equipment which remedies some of the deficiencies of secondary surveillance radar (SSR) is described. SSR principles are briefly reviewed, and the main problems of bearing measurement, cochannel interference, and multipath are described. The use of improved antennas in SSR is briefly addressed, and the application of monopulse principles to bearing measurement and reply decoding in SSR is examined. The extension of monopulse to Mode S, which will add an extended datalink capability, is discussed.

Stevens, M. C.

 
 
 
 
381

ILLEGAL MIGRATION-CONCEPTUAL DELIMITATIONS  

Directory of Open Access Journals (Sweden)

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

CRISTINA FLORINA POPESCU (PANAIT

2013-05-01