WorldWideScience

Sample records for hydrocarbon expulsion modeling

  1. One State's Systems Change Efforts to Reduce Child Care Expulsion: Taking the Pyramid Model to Scale

    Science.gov (United States)

    Vinh, Megan; Strain, Phil; Davidon, Sarah; Smith, Barbara J.

    2016-01-01

    This article describes the efforts funded by the state of Colorado to address unacceptably high rates of expulsion from child care. Based on the results of a 2006 survey, the state of Colorado launched two complementary policy initiatives in 2009 to impact expulsion rates and to improve the use of evidence-based practices related to challenging…

  2. One-Dimensional, Two-Phase Flow Modeling Toward Interpreting Motor Slag Expulsion Phenomena

    Science.gov (United States)

    Kibbey, Timothy P.

    2012-01-01

    Aluminum oxide slag accumulation and expulsion was previously shown to be a player in various solid rocket motor phenomena, including the Space Shuttle's Reusable Solid Rocket Motor (RSRM) pressure perturbation, or "blip," and phantom moment. In the latter case, such un ]commanded side accelerations near the end of burn have also been identified in several other motor systems. However, efforts to estimate the mass expelled during a given event have come up short. Either bulk calculations are performed without enough physics present, or multiphase, multidimensional Computational Fluid Dynamic analyses are performed that give a snapshot in time and space but do not always aid in grasping the general principle. One ]dimensional, two ]phase compressible flow calculations yield an analytical result for nozzle flow under certain assumptions. This can be carried further to relate the bulk motor parameters of pressure, thrust, and mass flow rate under the different exhaust conditions driven by the addition of condensed phase mass flow. An unknown parameter is correlated to airflow testing with water injection where mass flow rates and pressure are known. Comparison is also made to full ]scale static test motor data where thrust and pressure changes are known and similar behavior is shown. The end goal is to be able to include the accumulation and flow of slag in internal ballistics predictions. This will allow better prediction of the tailoff when much slag is ejected and of mass retained versus time, believed to be a contributor to the widely-observed "flight knockdown" parameter.

  3. Mechanistic model for microbial growth on hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Mallee, F M; Blanch, H W

    1977-12-01

    Based on available information describing the transport and consumption of insoluble alkanes, a mechanistic model is proposed for microbial growth on hydrocarbons. The model describes the atypical growth kinetics observed, and has implications in the design of large scale equipment for single cell protein (SCP) manufacture from hydrocarbons. The model presents a framework for comparison of the previously published experimental kinetic data.

  4. Insight into the process of product expulsion in cellobiohydrolase Cel6A from Trichoderma reesei by computational modeling.

    Science.gov (United States)

    Huang, Houhou; Han, Fei; Guan, Shanshan; Qian, Mengdan; Wan, Yongfeng; Shan, Yaming; Zhang, Hao; Wang, Song

    2018-03-24

    Glycoside hydrolase cellulase family 6 from Trichoderma reesei (TrCel6A) is an important cellobiohydrolase to hydrolyze cellooligosaccharide into cellobiose. The knowledge of enzymatic mechanisms is critical for improving the conversion efficiency of cellulose into ethanol or other chemicals. However, the process of product expulsion, a key component of enzymatic depolymerization, from TrCel6A has not yet been described in detail. Here, conventional molecular dynamics and steered molecular dynamics (SMD) were applied to study product expulsion from TrCel6A. Tyr103 may be a crucial residue in product expulsion given that it exhibits two different posthydrolytic conformations. In one conformation, Tyr103 rotates to open the -3 subsite. However, Tyr103 does not rotate in the other conformation. Three different routes for product expulsion were proposed on the basis of the two different conformations. The total energy barriers of the three routes were calculated through SMD simulations. The total energy barrier of product expulsion through Route 1, in which Tyr103 does not rotate, was 22.2 kcal·mol -1 . The total energy barriers of product expulsion through Routes 2 and 3, in which Tyr103 rotates to open the -3 subsite, were 10.3 and 14.4 kcal·mol -1 , respectively. Therefore, Routes 2 and 3 have lower energy barriers than Route 1, and Route 2 is the thermodynamically optimal route for product expulsion. Consequently, the rotation of Tyr103 may be crucial for product release from TrCel6A. Results of this work have potential applications in cellulase engineering.

  5. Secession and Expulsion

    DEFF Research Database (Denmark)

    Sweeney, Richard J.

    2003-01-01

    If secession or expulsion ends in a `velvet divorce,' as with Czechoslovakia, costs areminimal and the split is relatively unimportant. High costs arise if a federation splits into mutuallyhostile, comparably sized regions. Perhaps the majority of splits lead to dangerous hostility. Awell-designe...

  6. 2D compositional modeling of petroleum generation, expulsion and migration in the Southern compartment of the Reconcavo Basin, Brazil; Modelisation compositionnelle 2D de la genese, expulsion et migration du petrole dans le compartiment sud du Bassin de Reconcavo, Bresil

    Energy Technology Data Exchange (ETDEWEB)

    Barroz Penteado, H.L. de

    1999-01-07

    The Reconcavo Basin is part of a rift formed between the Late Jurassic and the Early Cretaceous in northeastern Brazil. The objective of this thesis was the compositional modeling of petroleum generation, expulsion and migration along a cross-section in the Southern Compartment of the basin with the Temispack basin simulation software. A geochemical study of the lacustrine shales of the Gomo Member (Candelas Fm.) has been performed to determine their petroleum potential, the evolution of maturation with depth and changes in petroleum composition. Hydrogen indices of immature kerogens (400-850 mg/g TOC) were shown to be higher than those of whole rocks, thus indicating a retention of Rock-Eval pyrolysis products in the mineral matrix of these type I source rocks. Saturates (30-50% of organic extracts in the immature zone) increase both in absolute and in relative (60-80%) terms in the oil window (2000-2600 m) because of a partial secondary cracking of NSOs and aromatics. After having tested several scenarios of geodynamic evolution between the Aptian and the Oligocene, a variable thickness of post-rift sediments (maximum of 1200 m) has been shown to be necessary to calibrate maturity parameters. Petroleum migration has been modeled to understand migration pathways as well as the role of faults as drains. Thus, two petroleum migration systems have been identified for the Dom Joao and Cexis accumulations. Petroleum compositional variations have been modeled by coupling the processes of retention and secondary cracking. A good calibration of compositions was obtained with secondary cracking parameters for NSOs and aromatics which are close to those of the main primary cracking reaction of a type I kerogen, coupled with a retention of 50% of NSOs within the source rocks. (author)

  7. Gas expulsions and biological activity recorded offshore Molene Island, Brittany (France): video supervised recording of OBS data and analogue modelling

    Science.gov (United States)

    Klingelhoefer, F.; Géli, L.; Dellong, D.; Evangelia, B.; Tary, J. B.; Bayrakci, G.; Lantéri, N.; Lin, J. Y.; Chen, Y. F.; Chang, E. T. Y.

    2016-12-01

    Ocean bottom seismometers (OBS) commonly record signals from Short Duration Events (SDEs), having characteristics that are very different from those produced by tectonic earthquakes, e.g.: durations Brittany within the field of view of the EMSO-Molene underwater observatory, at a water depth of 12 m. The camera images and the recordings reveal the presence of crabs, octopus and several species of fish. Other acoustic signals can be related to the presence of moving algae or the influence from bad weather. Tides produce characteristic curves in the noise recorded on the geophones. SDEs have been recorded on both instruments, that may well have been caused by gas expulsions from the seabed into the water. In order to verify this hypothesis, an aquarium was filled with water overlying an even grain-sized quartz sand layer. A constant air supply through a narrow tube produced gas bubbles in a regular manner and an immersed ocean bottom geophone recorded the resulting acoustic signals. The bubbles tend to have a uniform size and to produce a waveform very close to those found on the OBSs. By comparing the number of SDEs and the volume of escaped air, estimates can be made regarding the volume of gas escaping the seafloor in different environments.

  8. New method dynamically models hydrocarbon fractionation

    Energy Technology Data Exchange (ETDEWEB)

    Kesler, M.G.; Weissbrod, J.M.; Sheth, B.V. [Kesler Engineering, East Brunswick, NJ (United States)

    1995-10-01

    A new method for calculating distillation column dynamics can be used to model time-dependent effects of independent disturbances for a range of hydrocarbon fractionation. It can model crude atmospheric and vacuum columns, with relatively few equilibrium stages and a large number of components, to C{sub 3} splitters, with few components and up to 300 equilibrium stages. Simulation results are useful for operations analysis, process-control applications and closed-loop control in petroleum, petrochemical and gas processing plants. The method is based on an implicit approach, where the time-dependent variations of inventory, temperatures, liquid and vapor flows and compositions are superimposed at each time step on the steady-state solution. Newton-Raphson (N-R) techniques are then used to simultaneously solve the resulting finite-difference equations of material, equilibrium and enthalpy balances that characterize distillation dynamics. The important innovation is component-aggregation and tray-aggregation to contract the equations without compromising accuracy. This contraction increases the N-R calculations` stability. It also significantly increases calculational speed, which is particularly important in dynamic simulations. This method provides a sound basis for closed-loop, supervisory control of distillation--directly or via multivariable controllers--based on a rigorous, phenomenological column model.

  9. Hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    1927-02-22

    Coal tar, mineral oils, bitumens, coal extraction products, hydrogenation products of coal, oil schists can be atomized and heated with steam to decompose pyrogenetically and form gases rich in olefins which may be heated with or without pressure and with or without catalysts to produce liquid hydrocarbons of low boiling point, some of which may be aromatic. The apparatus should be lined with copper, silica, or ferrosilicon to prevent contact of the bases with iron which causes deposition of soot. Catalysts used may be metal oxides, silica, graphite, active charcoal, mica, pumice, porcelain, barium carbonate, copper, silver, gold, chromium, boron, or their compounds. At temperatures from 300 to 400/sup 0/C, olefins are produced. At higher temperatures, naphthenes and benzene hydrocarbons are produced.

  10. A Mechanical Modelling of the Primary Migration Modélisation mécanique de l'expulsion

    Directory of Open Access Journals (Sweden)

    Schneider F.

    2006-12-01

    Full Text Available In order to address the question of oil-induced microfracturing, we propose under specific assumptions (plane circular kerogen flake surrounded by an homogeneous microfractured porous medium an analytical method for the determination of the oil pressure increase. It is based on a mechanical modelling of the kerogen-oil-rock interaction at the microscopicscale of a kerogen particle. It is shown that the oil pressure tends towards an asymptotic value when the chemical transformation of kerogen is completed. The effect of the macroscopic stress variation during oil formation process proves to be negligible. However, this effect must be taken into account for describing the evolution of oil pressure at earlier stages of oil formation process. The increase in burial depth induces an increase of oil pressure as well as a variation of the macroscopic stress which both determine the microscopic stress field. The possibility of microfracturing depends on the position of the microscopic stress state with respect to the fracture criterion. If the duration of the oil formation process is short enough, so that the macroscopic stress change associated with the corresponding (small burial depth increase can be neglected, it is found that microfracturing is likely for the usual values of rock tensile strength. However, in the general case, neglecting the macroscopic stress change can significantly overestimate the possibility of fracture initiation due to oil-pressure increase. Considering now the macroscopicscale of the source bed, the evolution equation of the oil pressure are derived within the framework of Biot's poroelasticity theory. The oil pressure rate proves to be the sum of a diffusion term which accounts for oil migration within the source bed, and of two source terms respectively associated with the volume expansion tendency of the kerogen - oil transformation and the overburden pressure increase. Dans le but d'étudier le problème de la

  11. Mathematical modelling on transport of petroleum hydrocarbons

    Indian Academy of Sciences (India)

    A brief theory has been included on the composition and transport of petroleum hydrocarbons following an onshore oil spill in order to demonstrate the level of complexity associated with the LNAPL dissolution mass transfer even in a classical porous medium. However, such studies in saturated fractured rocks are highly ...

  12. Gas expulsion in highly substructured embedded star clusters

    Science.gov (United States)

    Farias, J. P.; Fellhauer, M.; Smith, R.; Domínguez, R.; Dabringhausen, J.

    2018-06-01

    We investigate the response of initially substructured, young, embedded star clusters to instantaneous gas expulsion of their natal gas. We introduce primordial substructure to the stars and the gas by simplistically modelling the star formation process so as to obtain a variety of substructure distributed within our modelled star-forming regions. We show that, by measuring the virial ratio of the stars alone (disregarding the gas completely), we can estimate how much mass a star cluster will retain after gas expulsion to within 10 per cent accuracy, no matter how complex the background structure of the gas is, and we present a simple analytical recipe describing this behaviour. We show that the evolution of the star cluster while still embedded in the natal gas, and the behaviour of the gas before being expelled, is crucial process that affect the time-scale on which the cluster can evolve into a virialized spherical system. Embedded star clusters that have high levels of substructure are subvirial for longer times, enabling them to survive gas expulsion better than a virialized and spherical system. By using a more realistic treatment for the background gas than our previous studies, we find it very difficult to destroy the young clusters with instantaneous gas expulsion. We conclude that gas removal may not be the main culprit for the dissolution of young star clusters.

  13. Stellar Wind Retention and Expulsion in Massive Star Clusters

    Science.gov (United States)

    Naiman, J. P.; Ramirez-Ruiz, E.; Lin, D. N. C.

    2018-05-01

    Mass and energy injection throughout the lifetime of a star cluster contributes to the gas reservoir available for subsequent episodes of star formation and the feedback energy budget responsible for ejecting material from the cluster. In addition, mass processed in stellar interiors and ejected as winds has the potential to augment the abundance ratios of currently forming stars, or stars which form at a later time from a retained gas reservoir. Here we present hydrodynamical simulations that explore a wide range of cluster masses, compactnesses, metallicities and stellar population age combinations in order to determine the range of parameter space conducive to stellar wind retention or wind powered gas expulsion in star clusters. We discuss the effects of the stellar wind prescription on retention and expulsion effectiveness, using MESA stellar evolutionary models as a test bed for exploring how the amounts of wind retention/expulsion depend upon the amount of mixing between the winds from stars of different masses and ages. We conclude by summarizing some implications for gas retention and expulsion in a variety of compact (σv ≳ 20 kms-1) star clusters including young massive star clusters (105 ≲ M/M⊙ ≲ 107, age ≲ 500 Myrs), intermediate age clusters (105 ≲ M/M⊙ ≲ 107, age ≈ 1 - 4 Gyrs), and globular clusters (105 ≲ M/M⊙ ≲ 107, age ≳ 10 Gyrs).

  14. Modeling of Antenna for Deep Target Hydrocarbon Exploration

    Directory of Open Access Journals (Sweden)

    Nadeem Nasir

    2017-11-01

    Full Text Available Nowadays control source electromagnetic method is used for offshore hydrocarbon exploration. Hydrocarbon detection in sea bed logging (SBL is a very challenging task for deep target hydrocarbon reservoir. Response of electromagnetic (EM field from marine environment is very low and it is very difficult to predict deep target reservoir below 2km from the sea floor. This work premise deals with modeling of new antenna for deep water deep target hydrocarbon exploration. Conventional and new EM antennas at 0.125Hz frequency are used in modeling for the detection of deep target hydrocarbon  reservoir.  The  proposed  area  of  the  seabed model   (40km ´ 40km   was   simulated   by using CST (computer simulation technology EM studio based on Finite Integration Method (FIM. Electromagnetic field components were compared at 500m target depth and it was concluded that Ex and Hz components shows better resistivity contrast. Comparison of conventional and new antenna for different target  depths  was  done in  our  proposed  model.  From  the results, it was observed that conventional antenna at 0.125Hz shows 70% ,86% resistivity contrast at target depth of 1000m where   as   new   antenna   showed   329%, 355%   resistivity contrast at the same target depth for Ex and Hz field respectively.  It  was  also  investigated  that  at  frequency of0.125Hz, new antenna gave 46% better delineation of hydrocarbon at 4000m target depth. This is due to focusing of electromagnetic waves by using new antenna. New antenna design gave 125% more extra depth than straight antenna for deep target hydrocarbon detection. Numerical modeling for straight  and  new antenna  was also done to know general equation for electromagnetic field behavior with target depth. From this numerical model it was speculated that this new antenna can detect up to 4.5 km target depth. This new EM antenna may open new frontiers for oil and gas

  15. A new biodegradation prediction model specific to petroleum hydrocarbons.

    Science.gov (United States)

    Howard, Philip; Meylan, William; Aronson, Dallas; Stiteler, William; Tunkel, Jay; Comber, Michael; Parkerton, Thomas F

    2005-08-01

    A new predictive model for determining quantitative primary biodegradation half-lives of individual petroleum hydrocarbons has been developed. This model uses a fragment-based approach similar to that of several other biodegradation models, such as those within the Biodegradation Probability Program (BIOWIN) estimation program. In the present study, a half-life in days is estimated using multiple linear regression against counts of 31 distinct molecular fragments. The model was developed using a data set consisting of 175 compounds with environmentally relevant experimental data that was divided into training and validation sets. The original fragments from the Ministry of International Trade and Industry BIOWIN model were used initially as structural descriptors and additional fragments were then added to better describe the ring systems found in petroleum hydrocarbons and to adjust for nonlinearity within the experimental data. The training and validation sets had r2 values of 0.91 and 0.81, respectively.

  16. Modeling of air toxics from hydrocarbon pool fires

    International Nuclear Information System (INIS)

    Harvey, K.A.; Aydil, M.L.; Barone, J.B.

    1996-01-01

    While there is guidance for estimating the radiation hazards of fires (ARCHIE), there is little guidance on modeling the dispersion of hazardous materials from fires. The objective of this paper is to provide a review of the methodology used for modeling the impacts of liquid hydrocarbon pool fires. The required input variables for modeling of hydrocarbon pool fires include emission strength, emission duration, and dispersion characteristics. Methods for predicting the products of combustion including the use of literature values, test data, and thermodynamic equilibrium calculations are discussed. The use of energy balances coupled to radiative heat transfer calculations are presented as a method for determining flame temperature. Fire modeling literature is reviewed in order to determine other source release variables such as mass burn rate and duration and flame geometry

  17. Interactive physically-based structural modeling of hydrocarbon systems

    International Nuclear Information System (INIS)

    Bosson, Mael; Grudinin, Sergei; Bouju, Xavier; Redon, Stephane

    2012-01-01

    Hydrocarbon systems have been intensively studied via numerical methods, including electronic structure computations, molecular dynamics and Monte Carlo simulations. Typically, these methods require an initial structural model (atomic positions and types, topology, etc.) that may be produced using scripts and/or modeling tools. For many systems, however, these building methods may be ineffective, as the user may have to specify the positions of numerous atoms while maintaining structural plausibility. In this paper, we present an interactive physically-based modeling tool to construct structural models of hydrocarbon systems. As the user edits the geometry of the system, atomic positions are also influenced by the Brenner potential, a well-known bond-order reactive potential. In order to be able to interactively edit systems containing numerous atoms, we introduce a new adaptive simulation algorithm, as well as a novel algorithm to incrementally update the forces and the total potential energy based on the list of updated relative atomic positions. The computational cost of the adaptive simulation algorithm depends on user-defined error thresholds, and our potential update algorithm depends linearly with the number of updated bonds. This allows us to enable efficient physically-based editing, since the computational cost is decoupled from the number of atoms in the system. We show that our approach may be used to effectively build realistic models of hydrocarbon structures that would be difficult or impossible to produce using other tools.

  18. MODELING GALACTIC EXTINCTION WITH DUST AND 'REAL' POLYCYCLIC AROMATIC HYDROCARBONS

    International Nuclear Information System (INIS)

    Mulas, Giacomo; Casu, Silvia; Cecchi-Pestellini, Cesare; Zonca, Alberto

    2013-01-01

    We investigate the remarkable apparent variety of galactic extinction curves by modeling extinction profiles with core-mantle grains and a collection of single polycyclic aromatic hydrocarbons. Our aim is to translate a synthetic description of dust into physically well-grounded building blocks through the analysis of a statistically relevant sample of different extinction curves. All different flavors of observed extinction curves, ranging from the average galactic extinction curve to virtually 'bumpless' profiles, can be described by the present model. We prove that a mixture of a relatively small number (54 species in 4 charge states each) of polycyclic aromatic hydrocarbons can reproduce the features of the extinction curve in the ultraviolet, dismissing an old objection to the contribution of polycyclic aromatic hydrocarbons to the interstellar extinction curve. Despite the large number of free parameters (at most the 54 × 4 column densities of each species in each ionization state included in the molecular ensemble plus the 9 parameters defining the physical properties of classical particles), we can strongly constrain some physically relevant properties such as the total number of C atoms in all species and the mean charge of the mixture. Such properties are found to be largely independent of the adopted dust model whose variation provides effects that are orthogonal to those brought about by the molecular component. Finally, the fitting procedure, together with some physical sense, suggests (but does not require) the presence of an additional component of chemically different very small carbonaceous grains.

  19. A comparison of nifedipine and tamsulosin as medical expulsive therapy for the management of lower ureteral stones without ESWL

    Science.gov (United States)

    Cao, Dehong; Yang, Lu; Liu, Liangren; Yuan, Haichao; Qian, Shenqiang; Lv, Xiao; Han, Pin; Wei, Qiang

    2014-01-01

    Administration of nifedipine or tamsulosin has been suggested to augment stone expulsion rates. We aimed to compare the stone expulsion rates and adverse effects associated with the use of nifedipine or tamsulosin as medical expulsive therapy (MET) for the management of lower ureteral stones (LUS) without extracorporeal shock wave lithotripsy (ESWL) via a literature review and meta-analysis. Relevant randomized controlled trials (RCTs) were identified from the Medline, EMBASE, Cochrane CENTRAL, and Google Scholar databases. Finally, a total of 7 RCTs with 3897 patients were included. Our meta-analysis showed that tamsulosin could significantly increase the stone expulsion rate relative to nifedipine in patients with LUS (random-effects model; risk ratio [RR] = 0.81; 95% confidence interval [CI] = 0.75–0.88; P tamsulosin was more effective than nifedipine in patients with LUS, as evidenced by the higher stone expulsion rate. Tamsulosin treatment should therefore be considered for patients with LUS. PMID:24919112

  20. Analytical Modeling Tool for Design of Hydrocarbon Sensitive Optical Fibers

    Directory of Open Access Journals (Sweden)

    Khalil Al Handawi

    2017-09-01

    Full Text Available Pipelines are the main transportation means for oil and gas products across large distances. Due to the severe conditions they operate in, they are regularly inspected using conventional Pipeline Inspection Gages (PIGs for corrosion damage. The motivation for researching a real-time distributed monitoring solution arose to mitigate costs and provide a proactive indication of potential failures. Fiber optic sensors with polymer claddings provide a means of detecting contact with hydrocarbons. By coating the fibers with a layer of metal similar in composition to that of the parent pipeline, corrosion of this coating may be detected when the polymer cladding underneath is exposed to the surrounding hydrocarbons contained within the pipeline. A Refractive Index (RI change occurs in the polymer cladding causing a loss in intensity of a traveling light pulse due to a reduction in the fiber’s modal capacity. Intensity losses may be detected using Optical Time Domain Reflectometry (OTDR while pinpointing the spatial location of the contact via time delay calculations of the back-scattered pulses. This work presents a theoretical model for the above sensing solution to provide a design tool for the fiber optic cable in the context of hydrocarbon sensing following corrosion of an external metal coating. Results are verified against the experimental data published in the literature.

  1. Analytical Modeling Tool for Design of Hydrocarbon Sensitive Optical Fibers.

    Science.gov (United States)

    Al Handawi, Khalil; Vahdati, Nader; Shiryayev, Oleg; Lawand, Lydia

    2017-09-28

    Pipelines are the main transportation means for oil and gas products across large distances. Due to the severe conditions they operate in, they are regularly inspected using conventional Pipeline Inspection Gages (PIGs) for corrosion damage. The motivation for researching a real-time distributed monitoring solution arose to mitigate costs and provide a proactive indication of potential failures. Fiber optic sensors with polymer claddings provide a means of detecting contact with hydrocarbons. By coating the fibers with a layer of metal similar in composition to that of the parent pipeline, corrosion of this coating may be detected when the polymer cladding underneath is exposed to the surrounding hydrocarbons contained within the pipeline. A Refractive Index (RI) change occurs in the polymer cladding causing a loss in intensity of a traveling light pulse due to a reduction in the fiber's modal capacity. Intensity losses may be detected using Optical Time Domain Reflectometry (OTDR) while pinpointing the spatial location of the contact via time delay calculations of the back-scattered pulses. This work presents a theoretical model for the above sensing solution to provide a design tool for the fiber optic cable in the context of hydrocarbon sensing following corrosion of an external metal coating. Results are verified against the experimental data published in the literature.

  2. Evaluation on occluded hydrocarbon in deep–ultra deep ancient source rocks and its cracked gas resources

    Directory of Open Access Journals (Sweden)

    Jian Li

    2015-12-01

    Full Text Available Oil-cracked gas, as the main type of high-over mature marine natural gas in China, is mainly derived from occluded hydrocarbon. So it is significant to carry out quantitative study on occluded hydrocarbon. In this paper, the occluded hydrocarbon volume of the main basins in China was calculated depending on their types, abundances and evolution stages by means of the forward method (experimental simulation and the inversion method (geologic profile dissection. And then, occluded hydrocarbon evolution models were established for five types of source rocks (sapropelic, sapropelic prone hybrid, humic prone hybrid, humic and coal. It is shown that the hydrocarbon expulsion efficiency of sapropelic and sapropelic prone hybrid excellent source rocks is lower than 30% at the low-maturity stage, 30%–60% at the principal oil generation stage, and 50%–80% at the high-maturity stage, which are all about 10% higher than that of humic prone hybrid and humic source rocks at the corresponding stages. The resource distribution and cracked gas expulsion of occluded hydrocarbon since the high-maturity stage of marine source rocks in the Sichuan Basin were preliminarily calculated on the basis of the evolution models. The cracked gas expulsion is 230.4 × 1012 m3 at the high evolution stage of occluded hydrocarbon of the Lower Cambrian Qiongzhusi Fm in this basin, and 12.3 × 1012 m3 from the source rocks of Sinian Doushantuo Fm, indicating good potential for natural gas resources. It is indicated that the favorable areas of occluded hydrocarbon cracked gas in the Qiongzhusi Fm source rocks in the Sichuan Basin include Gaoshiti–Moxi, Ziyang and Weiyuan, covering a favorable area of 4.3 × 104 km2.

  3. Petroleum systems and hydrocarbon accumulation models in the Santos Basin, SP, Brazil; Sistemas petroliferos e modelos de acumulacao de hidrocarbonetos na Bacia de Santos

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Hung Kiang; Assine, Mario Luis; Correa, Fernando Santos; Tinen, Julio Setsuo [Universidade Estadual Paulista (UNESP), Rio Claro, SP (Brazil). Lab. de Estudos de Bacias]. E-mails: chang@rc.unesp.br; assine@rc.unesp.br; fscorrea@rc.unesp.br; jstinen@rc.unesp.br; Vidal, Alexandre Campane; Koike, Luzia [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Centro de Estudos de Petroleo]. E-mails: vidal@ige.unicamp.br; luzia@iqm.unicamp.br

    2008-07-01

    The Santos Basin was formed by rifting process during Mesozoic Afro-American separation. Sediment accumulation initiated with fluvial-lacustrine deposits, passing to evaporitic stage until reaching marginal basin stages. The analysis of hydrocarbon potential of Santos Basin identified two petroleum systems: Guaratiba-Guaruja and Itajai-Acu-Ilhabela. The Guaratiba Formation is less known in the Santos Basin because of small number of wells that have penetrated the rift section. By comparison with Campos Basin, hydrocarbons are of saline lacustrine origin deposited in Aptian age. Analogous to Campos Basin the major source rock is of saline-lacustrine origin, which has been confirmed from geochemical analyses of oil samples recovered from the various fields. These analyses also identified marine source rock contribution, indicating the Itajai-Acu source rock went through oil-window, particularly in structural lows generated by halokynesis. Models of hydrocarbon accumulation consider Guaratiba Formacao as the major source rock for shallow carbonate reservoirs of Guaruja Formacao and for late Albian to Miocene turbidites, as well as siliciclastic and carbonate reservoirs of the rift phase. Migration occurs along salt window and through carrier-beds. The seal rock is composed of shales and limestones intercalated with reservoir facies of the post-rift section and by thick evaporites overlying rift section, especially in the deeper water. In the shallow portion, shale inter-tongued with reservoir rocks is the main seal rock. The hydrocarbon generation and expulsion in the central-north portion of the basin is caused by overburden of a thick Senonian section. Traps can be structural (rollovers and turtle), stratigraphic (pinch-outs) and mixed origins (pinch-outs of turbidites against salt domes). (author)

  4. New Insight into the Kinetics of Deep Liquid Hydrocarbon Cracking and Its Significance

    Directory of Open Access Journals (Sweden)

    Wenzhi Zhao

    2017-01-01

    Full Text Available The deep marine natural gas accumulations in China are mainly derived from the cracking of liquid hydrocarbons with different occurrence states. Besides accumulated oil in reservoir, the dispersed liquid hydrocarbon in and outside source also is important source for cracking gas generation or relayed gas generation in deep formations. In this study, nonisothermal gold tube pyrolysis and numerical calculations as well as geochemical analysis were conducted to ascertain the expulsion efficiency of source rocks and the kinetics for oil cracking. By determination of light liquid hydrocarbons and numerical calculations, it is concluded that the residual bitumen or hydrocarbons within source rocks can occupy about 50 wt.% of total oil generated at oil generation peak. This implies that considerable amounts of natural gas can be derived from residual hydrocarbon cracking and contribute significantly to the accumulation of shale gas. Based on pyrolysis experiments and kinetic calculations, we established a model for the cracking of oil and its different components. In addition, a quantitative gas generation model was also established to address the contribution of the cracking of residual oil and expulsed oil for natural gas accumulations in deep formations. These models may provide us with guidance for gas resource evaluation and future gas exploration in deep formations.

  5. Modeling the fate of polynuclear aromatic hydrocarbons in the rhizosphere

    International Nuclear Information System (INIS)

    Santharam, S.K.; Erickson, L.E.; Fan, L.T.

    1994-01-01

    Polynuclear aromatic hydrocarbons (PAHs) are major contaminants associated with wastes from manufactured gas plants, wood treating operations, and petroleum refining; they are potentially carcinogenic and mutagenic. It has been known that vegetation can enhance the rate and extent of degradation of PAHs in contaminated soil. Plant roots release exudates capable of supplying carbon and energy to microflora for degrading PAHs. It has also been well established that the population of microorganisms in the rhizosphere is significantly greater than that in the non-vegetated soil; these microorganisms are apparently responsible for the enhanced biodegradation of PAHs. A model has been derived for describing the rate of disappearance of a non-aqueous phase contaminant in the rhizosphere, which takes into account dissolution, adsorption, desorption and biodegradation of the contaminant, without neglecting the size distribution of the organic-phase droplets; the rate of biodegradation is expressed in terms of the Monod kinetics. The model is validated with the available experimental data for pyrene

  6. Detailed modeling of hydrocarbon nanoparticle nucleation in acetylene discharges

    International Nuclear Information System (INIS)

    Bleecker, Kathleen de; Bogaerts, Annemie; Goedheer, Wim

    2006-01-01

    The initial stage of nanoparticle formation and growth in radiofrequency acetylene (C 2 H 2 ) plasmas is investigated by means of a self-consistent one-dimensional fluid model. A detailed chemical kinetic scheme, containing electron impact, ion-neutral, and neutral-neutral reactions, has been developed in order to predict the underlying dust growth mechanisms and the most important dust precursors. The model considers 41 different species (neutrals, radicals, ions, and electrons) describing hydrocarbons (C n H m ) containing up to 12 carbon atoms. Possible routes for particle growth are discussed. Both positive and negative ion reaction pathways are considered, as consecutive anion- and cation-molecule reactions seem to lead to a fast build up of the carbon skeleton

  7. Electron localization in liquid hydrocarbons: The Anderson model

    International Nuclear Information System (INIS)

    Hug, Gordon L.; Mozumder, A.

    2008-01-01

    Anderson's model is applied for initial localization in liquid hydrocarbons (particularly n-alkanes) in conjunction with certain results of scaling theory. Medium connectivity is calculated using experimental X-ray data on liquid structure, from which critical disorder (W/V) c is computed, where W is diagonal disorder and V is the transfer energy. Actual W prevailing in the liquid is computed from anisotropic molecular polarizability. V is estimated by a heuristic procedure originating in scaling theory. These values are used to compute the percentage of initially delocalized states available for low-energy electrons in alkane liquids. This percentage decreases monotonically from methane (100%) to n-pentane and beyond (0%). In ethane and propane, the initial states are highly delocalized (97.6% and 83.9%, respectively). Subsequent trapping changes the situation as evidenced in mobility studies. Butane presents a partially, intermediate delocalized case (53.2%)

  8. First principles modeling of hydrocarbons conversion in non-equilibrium plasma

    Energy Technology Data Exchange (ETDEWEB)

    Deminsky, M.A.; Strelkova, M.I.; Durov, S.G.; Jivotov, V.K.; Rusanov, V.D.; Potapkin, B.V. [Russian Research Centre Kurchatov Inst., Moscow (Russian Federation)

    2001-07-01

    Theoretical justification of catalytic activity of non-equilibrium plasma in hydrocarbons conversion process is presented in this paper. The detailed model of highest hydrocarbons conversion includes the gas-phase reactions, chemistry of the growth of polycyclic aromatic hydrocarbons (PAHs), precursor of soot particles formation, neutral, charged clusters and soot particle formation, ion-molecular gas-phase and heterogeneous chemistry. The results of theoretical analysis are compared with experimental results. (authors)

  9. Expulsion of swimming bacteria by a circular flow

    Science.gov (United States)

    Sokolov, Andrey; Aronson, Igor

    Macroscopic shear flow alters swimming trajectories in a highly nontrivial way and results in dramatic reduction of viscosity and heterogeneous bacterial distributions. We report on experimental and theoretical studies of rapid expulsion of microswimmers, such as motile bacteria, by a circular flow created by a rotating microparticle. We observed a formation of a macroscopic depletion area in a high-shear region, in the vicinity of a microparticle. The rapid migration of bacteria from the shear-rich area is caused by a circular structure of the flow rather than intrinsic random fluctuations of bacteria orientations, in stark contrast to planar shear flow. Our mathematical model revealed that expulsion is a combined effect of motility and alignment by a vortical flow. Our findings offer a novel approach for manipulation of motile microorganisms and shed new light on bacteria-flow interactions. Was supported by the US DOE, Office of Basic Energy Sciences, Division of Materials Science And Engineering, under Contract No. DE AC02-06CH11357.

  10. Hydrocarbon Fuel Thermal Performance Modeling based on Systematic Measurement and Comprehensive Chromatographic Analysis

    Science.gov (United States)

    2016-07-31

    distribution unlimited Hydrocarbon Fuel Thermal Performance Modeling based on Systematic Measurement and Comprehensive Chromatographic Analysis Matthew...vital importance for hydrocarbon -fueled propulsion systems: fuel thermal performance as indicated by physical and chemical effects of cooling passage... analysis . The selection and acquisition of a set of chemically diverse fuels is pivotal for a successful outcome since test method validation and

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

    International Nuclear Information System (INIS)

    Rangel, Antonio; Hernandez, Roberto

    2007-01-01

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

  12. Mathematical modelling on transport of petroleum hydrocarbons in ...

    Indian Academy of Sciences (India)

    Groundwater being the world's most extracted raw material, with withdrawal rates .... and analytical results, while Petroleum Hydro-Carbons (PHC) generally ... and pipeline ruptures form the major source of groundwater contamination by ...

  13. Does Pelvic Organ Prolapse Relate with Expulsion of Intrauterine Devices?

    Directory of Open Access Journals (Sweden)

    Mehmet Çınar

    2016-08-01

    CONCLUSION: As interestingly; we found that POP-Q assessment should be a promising marker in predicting IUD expulsion. To the best of our knowledge, this is the first study with a such result, therefore POP-Q evaluation should be a useful parameter for future IUD expulsion.

  14. A chemical and thermodynamic model of oil generation in hydrocarbon source rocks

    Science.gov (United States)

    Helgeson, Harold C.; Richard, Laurent; McKenzie, William F.; Norton, Denis L.; Schmitt, Alexandra

    2009-02-01

    can be computed from power functions of temperature along a typical US Gulf Coast geotherm. All of these reactions and relations are consistent with the well-known observations that (1) the relative abundance of mature kerogen increases, and that of immature kerogen decreases with increasing burial of hydrocarbon source rocks and (2) that the volume of oil generated in a given source rock increases with increasing weight percent total organic carbon (TOC) and the H/C and (to a lesser extent) the O/C of the immature kerogen. They are also compatible with preservation of biomarkers and other polymerized hydrocarbons during the incongruent melting process. It can be deduced from Reaction (A) that nearly 11 mol of crude oil are produced from one mole of the reactant kerogen (rk), which increases to ˜39.5 mol (mol rk) -1 as the carbon content and H/C of the reactant kerogen increase to that in the hydrogen-rich type-I kerogen represented by C 415H 698O 22(c). The secondary porosities created in source rocks by Reaction (A) and others like it are of the order of 75-80 vol % of the oil generated, which requires expulsion of the remainder, together with the CO 2 gas produced by the reaction. The expulsion of the CO 2 gas and excess crude oil from the hydrocarbon source rock is facilitated by their buoyancy and the fact that the pressure in the source rocks is ⩾ the fluid pressure in the adjoining formations during progressive generation of the volume of crude oil that exceeds the kerogen pore volume produced by the incongruent melting process. The expelled CO 2 gas lowers the pH of the surrounding formation waters, which promotes the development of secondary porosity and diagenetic reaction of detrital silicates to form authigenic mineral assemblages. Hence, the expulsion process facilitates initial upward migration of the oil, which is further enhanced by expansion of the oil and its reaction with H 2O at the oil-water interface to generate methane gas. Mass transfer

  15. Polycyclic aromatic hydrocarbons in model bacterial membranes - Langmuir monolayer studies.

    Science.gov (United States)

    Broniatowski, Marcin; Binczycka, Martyna; Wójcik, Aneta; Flasiński, Michał; Wydro, Paweł

    2017-12-01

    High molecular weight polycyclic aromatic hydrocarbons (HMW-PAHs) are persistent organic pollutants which due to their limited biodegradability accumulate in soils where their increased presence can lead to the impoverishment of the decomposer organisms. As very hydrophobic PAHs easily penetrate cellular membranes of soil bacteria and can be incorporated therein, changing the membrane fluidity and other functions which in consequence can lead to the death of the organism. The structure and size of PAH molecule can be crucial for its membrane activity; however the correlation between PAH structure and its interaction with phospholipids have not been investigated so far. In our studies we applied phospholipid Langmuir monolayers as model bacterial membranes and investigated how the incorporation of six structurally different PAH molecules change the membrane texture and physical properties. In our studies we registered surface pressure and surface potential isotherms upon the monolayer compression, visualized the monolayer texture with the application of Brewster angle microscopy and searched the ordering of the film-forming molecules with molecular resolution with the application of grazing incidence X-ray diffraction (GIXD) method. It turned out that the phospholipid-PAH interactions are strictly structure dependent. Four and five-ring PAHs of the angular or cluster geometry can be incorporated into the model membranes changing profoundly their textures and fluidity; whereas linear or large cluster PAHs cannot be incorporated and separate from the lipid matrix. The observed phenomena were explained based on structural similarities of the applied PAHs with membrane steroids and hopanoids. Copyright © 2017. Published by Elsevier B.V.

  16. Summary report of project SIREN (Search, Intercept, Retrieve, Expulsion, Nuclear)

    International Nuclear Information System (INIS)

    Buden, D.

    1992-12-01

    Project SIREN (Search, Intercept, Retrieve, Expulsion, Nuclear) has evaluated the technologies and operational strategies needed to rendezvous with and capture aerospace radioactive materials (e.g., a distressed or spent space reactor core) before such materials can reenter the terrestrial atmosphere and to move these captured materials to a space destination for proper disposal. The use of systems external to a satellite allows multiple attempts to prevent the nuclear materials from reentering the atmosphere. SIREN also has investigated means to prevent the breakup of nuclear-powered systems already in space. The SIREN project has determined that external means can be used reliably to prevent nuclear materials from reentering the terrestrial environment, prepared a computer model that can be used to evaluate the means to dispose of radioactive materials, assessed the hazards from existing nuclear power systems in space, and in discussions with Russian Federation representatives determined interest in joint activities in this area

  17. Near omni-conductors and insulators: Alternant hydrocarbons in the SSP model of ballistic conduction

    OpenAIRE

    Fowler, P.W.; Sciriha, I.; Borg, M.; Seville, V.E.; Pickup, B.T.

    2017-01-01

    Within the source-and-sink-potential model, a complete characterisation is obtained for the conduction behaviour of alternant π-conjugated hydrocarbons (conjugated hydrocarbons without odd cycles). In this model, an omni-conductor has a molecular graph that conducts at the Fermi level irrespective of the choice of connection vertices. Likewise, an omni-insulator is a molecular graph that fails to conduct for any choice of connections. We give a comprehensive classification of possible combina...

  18. Receptor Model Source Apportionment of Nonmethane Hydrocarbons in Mexico City

    Directory of Open Access Journals (Sweden)

    V. Mugica

    2002-01-01

    Full Text Available With the purpose of estimating the source contributions of nonmethane hydrocarbons (NMHC to the atmosphere at three different sites in the Mexico City Metropolitan Area, 92 ambient air samples were measured from February 23 to March 22 of 1997. Light- and heavy-duty vehicular profiles were determined to differentiate the NMHC contribution of diesel and gasoline to the atmosphere. Food cooking source profiles were also determined for chemical mass balance receptor model application. Initial source contribution estimates were carried out to determine the adequate combination of source profiles and fitting species. Ambient samples of NMHC were apportioned to motor vehicle exhaust, gasoline vapor, handling and distribution of liquefied petroleum gas (LP gas, asphalt operations, painting operations, landfills, and food cooking. Both gasoline and diesel motor vehicle exhaust were the major NMHC contributors for all sites and times, with a percentage of up to 75%. The average motor vehicle exhaust contributions increased during the day. In contrast, LP gas contribution was higher during the morning than in the afternoon. Apportionment for the most abundant individual NMHC showed that the vehicular source is the major contributor to acetylene, ethylene, pentanes, n-hexane, toluene, and xylenes, while handling and distribution of LP gas was the major source contributor to propane and butanes. Comparison between CMB estimates of NMHC and the emission inventory showed a good agreement for vehicles, handling and distribution of LP gas, and painting operations; nevertheless, emissions from diesel exhaust and asphalt operations showed differences, and the results suggest that these emissions could be underestimated.

  19. Gas expulsion vs gas retention in young stellar clusters II: effects of cooling and mass segregation

    Science.gov (United States)

    Silich, Sergiy; Tenorio-Tagle, Guillermo

    2018-05-01

    Gas expulsion or gas retention is a central issue in most of the models for multiple stellar populations and light element anti-correlations in globular clusters. The success of the residual matter expulsion or its retention within young stellar clusters has also a fundamental importance in order to understand how star formation proceeds in present-day and ancient star-forming galaxies and if proto-globular clusters with multiple stellar populations are formed in the present epoch. It is usually suggested that either the residual gas is rapidly ejected from star-forming clouds by stellar winds and supernova explosions, or that the enrichment of the residual gas and the formation of the second stellar generation occur so rapidly, that the negative stellar feedback is not significant. Here we continue our study of the early development of star clusters in the extreme environments and discuss the restrictions that strong radiative cooling and stellar mass segregation provide on the gas expulsion from dense star-forming clouds. A large range of physical initial conditions in star-forming clouds which include the star-forming cloud mass, compactness, gas metallicity, star formation efficiency and effects of massive stars segregation are discussed. It is shown that in sufficiently massive and compact clusters hot shocked winds around individual massive stars may cool before merging with their neighbors. This dramatically reduces the negative stellar feedback, prevents the development of the global star cluster wind and expulsion of the residual and the processed matter into the ambient interstellar medium. The critical lines which separate the gas expulsion and the gas retention regimes are obtained.

  20. Spontaneous expulsive suprachoroidal hemorrhage caused by decompensated liver disease

    Directory of Open Access Journals (Sweden)

    Krishnagopal Srikanth

    2013-01-01

    Full Text Available Expulsive suprachoroidal hemorrhage can be surgical or spontaneous. Spontaneous expulsive suprachoroidal hemorrhage (SESCH is a rare entity. Most of the reported cases of SESCH were caused by a combination of corneal pathology and glaucoma. We are reporting a rare presentation of SESCH with no pre-existing glaucoma or corneal pathology and caused by massive intra- and peri-ocular hemorrhage due to decompensated liver disease.

  1. Medical expulsive treatment of distal ureteral stone using tamsulosin

    International Nuclear Information System (INIS)

    Ahmad, H.; Azim, W.; Akmal, M.; Murtaza, B.

    2015-01-01

    Many minimally invasive interventional techniques as well as expectant treatments exist for the management of lower ureteric calculi. This study was conducted to evaluate the efficacy of tamsulosin as an expulsive pharmacologic therapy for the treatment of distal ureteral stone. Methods: This randomized control trial included 100 patients over 18 years of age with stone Size = 8mm in distal 1/3 of ureter. Patients were randomly assigned into two groups (A and B). Group A Patients were given Capsule Tamsulosin 0.4 mg, 1 daily up to 4 weeks while group B patients were given placebo, 1 Capsule daily up to 4 weeks. The primary endpoint was expulsion rate. A written informed consent was taken from all the patients. Expulsion time, need for analgesics, need for hospitalization and drug side effects were secondary endpoints. Results: A total of 49 patients in group A and 48 patients in group B reported back, therefore 97 out of 100 patients were evaluated. Mean age of the patients was 36.34 years (range 18-57 years). Mean stone size was 5.78 mm (range 4-8 mm) in greatest dimension. A stone expulsion rate of 85.71% (42 patients) was noted in group A and 54.20% (26 patients) in group B. Group A revealed a statistically significant advantage in term of stone expulsion rate (p=0.032). Considering expulsion time in days group A showed statistically significant advantage (p=0.015). Regarding age, sex, stone size and stone lateralization (right/left), there was no significant difference between the group A and B. No drug side effects were noted in both the groups. Conclusion: By using tamsulosin a higher stone expulsion rates can be achieved in a shorter time. More randomized control trials are required to establish tamsulosin as a standard medical expulsive treatment for small distal ureteric calculus. (author)

  2. A comparison of nifedipine and tamsulosin as medical expulsive therapy for the management of lower ureteral stones without ESWL.

    Science.gov (United States)

    Cao, Dehong; Yang, Lu; Liu, Liangren; Yuan, Haichao; Qian, Shenqiang; Lv, Xiao; Han, Pin; Wei, Qiang

    2014-06-11

    Administration of nifedipine or tamsulosin has been suggested to augment stone expulsion rates. We aimed to compare the stone expulsion rates and adverse effects associated with the use of nifedipine or tamsulosin as medical expulsive therapy (MET) for the management of lower ureteral stones (LUS) without extracorporeal shock wave lithotripsy (ESWL) via a literature review and meta-analysis. Relevant randomized controlled trials (RCTs) were identified from the Medline, EMBASE, Cochrane CENTRAL, and Google Scholar databases. Finally, a total of 7 RCTs with 3897 patients were included. Our meta-analysis showed that tamsulosin could significantly increase the stone expulsion rate relative to nifedipine in patients with LUS (random-effects model; risk ratio [RR] = 0.81; 95% confidence interval [CI] = 0.75-0.88; P < 0.00001). The subgroup analysis indicated no statistically significant difference between the drugs with regard to minor or major adverse effects (fixed-effect model; RR = 1.19, 95% CI = 0.91-1.54, P = 0.20; and RR = 1.63, 95% CI = 0.22-11.82, P = 0.63, respectively). This meta-analysis demonstrated that tamsulosin was more effective than nifedipine in patients with LUS, as evidenced by the higher stone expulsion rate. Tamsulosin treatment should therefore be considered for patients with LUS.

  3. Flux expulsion and trapping in rotating discs of type II superconductors

    International Nuclear Information System (INIS)

    Boyer, R.; Leblanc, M.A.R.

    1977-01-01

    The magnetic flux rotating in step with a type II superconducting disc is measured with orthogonal pick up coils for various previous magnetic histories vs H 0 applied at right angles to the axis of rotation. For some initial magnetic states, flux expulsion, independent of the rate of rotation, occurs during the initial rotation. A simple model where flux lines leave the specimen against the magnetic pressure in the active region accounts for the observations. (author)

  4. New flow boiling heat transfer model for hydrocarbons evaporating inside horizontal tubes

    International Nuclear Information System (INIS)

    Chen, G. F.; Gong, M. Q.; Wu, J. F.; Zou, X.; Wang, S.

    2014-01-01

    Hydrocarbons have high thermodynamic performances, belong to the group of natural refrigerants, and they are the main components in mixture Joule-Thomson low temperature refrigerators (MJTR). New evaluations of nucleate boiling contribution and nucleate boiling suppression factor in flow boiling heat transfer have been proposed for hydrocarbons. A forced convection heat transfer enhancement factor correlation incorporating liquid velocity has also been proposed. In addition, the comparisons of the new model and other classic models were made to evaluate its accuracy in heat transfer prediction

  5. Application of Geographic Information System (GIS) to Model the Hydrocarbon Migration: Case Study from North-East Malay Basin, Malaysia

    Science.gov (United States)

    Rudini; Nasir Matori, Abd; Talib, Jasmi Ab; Balogun, Abdul-Lateef

    2018-03-01

    The purpose of this study is to model the migration of hydrocarbon using Geographic Information System (GIS). Understanding hydrocarbon migration is important since it can mean the difference between success and failure in oil and gas exploration project. The hydrocarbon migration modeling using geophysical method is still not accurate due to the limitations of available data. In recent years, GIS has emerged as a powerful tool for subsurface mapping and analysis. Recent studies have been carried out about the abilities of GIS to model hydrocarbon migration. Recent advances in GIS support the establishment and monitoring of prediction hydrocarbon migration. The concept, model, and calculation are based on the current geological situation. The spatial data of hydrocarbon reservoirs is determined by its geometry of lithology and geophysical attributes. Top of Group E horizon of north-east Malay basin was selected as the study area due to the occurrence of hydrocarbon migration. Spatial data and attributes data such as seismic data, wells log data and lithology were acquired and processed. Digital Elevation Model (DEM) was constructed from the selected horizon as a result of seismic interpretation using the Petrel software. Furthermore, DEM was processed in ArcGIS as a base map to shown hydrocarbon migration in north-east Malay Basin. Finally, all the data layers were overlaid to produce a map of hydrocarbon migration. A good data was imported to verify the model is correct.

  6. Application of Geographic Information System (GIS to Model the Hydrocarbon Migration: Case Study from North-East Malay Basin, Malaysia

    Directory of Open Access Journals (Sweden)

    Rudini

    2018-01-01

    Full Text Available The purpose of this study is to model the migration of hydrocarbon using Geographic Information System (GIS. Understanding hydrocarbon migration is important since it can mean the difference between success and failure in oil and gas exploration project. The hydrocarbon migration modeling using geophysical method is still not accurate due to the limitations of available data. In recent years, GIS has emerged as a powerful tool for subsurface mapping and analysis. Recent studies have been carried out about the abilities of GIS to model hydrocarbon migration. Recent advances in GIS support the establishment and monitoring of prediction hydrocarbon migration. The concept, model, and calculation are based on the current geological situation. The spatial data of hydrocarbon reservoirs is determined by its geometry of lithology and geophysical attributes. Top of Group E horizon of north-east Malay basin was selected as the study area due to the occurrence of hydrocarbon migration. Spatial data and attributes data such as seismic data, wells log data and lithology were acquired and processed. Digital Elevation Model (DEM was constructed from the selected horizon as a result of seismic interpretation using the Petrel software. Furthermore, DEM was processed in ArcGIS as a base map to shown hydrocarbon migration in north-east Malay Basin. Finally, all the data layers were overlaid to produce a map of hydrocarbon migration. A good data was imported to verify the model is correct.

  7. The Expulsion of "Pernicious" Foreigners in Colombia in Recent Years of Conservative Hegemony

    Directory of Open Access Journals (Sweden)

    Roger Pita Pico

    2017-01-01

    Full Text Available In the early twentieth century occurred in Colombia increased influx of foreigners but also increased political control in the entry and stay of these individuals. As part of social history and documentaries based on archival sources, this paper analyzes the process of expulsion of undocumented aliens and "pernicious" at the end of the presidential government of Miguel Abadía Mendez (1926-1930. This article aims to examine the reasons for these deportations, the measures taken against women prostitutes, the fate of the escapees and absolved and, finally, the complications that revolved around expulsion proceedings. This concern of the government by the presence of foreigners "pernicious" was in the interest of achieving national security through a social model in which were seriously questioned practices such as vagrancy, begging, theft, fraud, prostitution and seditious political activities.

  8. Utilization of biomass: Conversion of model compounds to hydrocarbons over zeolite H-ZSM-5

    DEFF Research Database (Denmark)

    Mentzel, Uffe Vie; Holm, Martin Spangsberg

    2011-01-01

    Zeolite catalyzed deoxygenation of small oxygenates present in bio-oil or selected as model compounds was performed under Methanol-to-Hydrocarbons (MTH) like reaction conditions using H-ZSM-5 as the catalyst. Co-feeding of the oxygenates with methanol generally decreases catalyst lifetime due...

  9. Medical expulsive therapy for distal ureteric stones: tamsulosin versus silodosin

    Directory of Open Access Journals (Sweden)

    Vittorio Imperatore

    2014-06-01

    Full Text Available Objectives: To compare the efficacy and safety of tamsulosin and silodosin in the context of medical expulsive therapy (MET of distal ureteric stones. Patients and methods: Observational data were collected retrospectively from patients who received silodosin (N = 50 or tamsulosin (N = 50 as MET from January 2012 to January 2013. Inclusion criteria were: patients aged ≥ 18 years with a single, unilateral, symptomatic, radiopaque ureteric stone of 10 mm or smaller in the largest dimension located between the lower border of the sacroiliac joint and the vesico-ureteric junction. Stone expulsion rate, stone expulsion time, number of pain episodes, need for analgesics use, incidence of side effects were compared. Results: Stone-expulsion rate in the silodosin and in the tamsulosin groups were 88% and 82%, respectively (p not significant. Mean expulsion times were 6.7 and 6.5 days in the silodosin and tamsulosin group, respectively (p not significant. Mean number of pain episodes were 1.6 and 1.7 in the silodosin and tamsulosin group, respectively (p not significant. The mean number of analgesic requirement was 0.84 and 0.9 for the silodosin and tamsulosin group, respectively (p not significant. Overall, incidence of side effects was similar in both groups. Patients taking silodosin experienced an higher incidence of retrograde ejaculation but a lower incidence of side effects related to peripheral vasodilation when compared to patients taking tamsulosin. Subgroup analysis demonstrated significantly lower mean expulsion times and pain episodes in patients with stones ≤ 5 mm in both groups. Conclusions: Tamsulosin and silodosin are equally effective as MET for distal ureteric stones sized 10 mm or smaller. MET with silodosin is associatd with a lower incidence of side effects related to peripheral vasodilation but an higher incidence of retrograde ejaculation when compared to tamsulosin.

  10. Medical expulsive therapy for distal ureteric stones: tamsulosin versus silodosin.

    Science.gov (United States)

    Imperatore, Vittorio; Fusco, Ferdinando; Creta, Massimiliano; Di Meo, Sergio; Buonopane, Roberto; Longo, Nicola; Imbimbo, Ciro; Mirone, Vincenzo

    2014-06-30

    To compare the efficacy and safety of tamsulosin and silodosin in the context of medical expulsive therapy (MET) of distal ureteric stones. Observational data were collected retrospectively from patients who received silodosin (N = 50) or tamsulosin (N = 50) as MET from January 2012 to January 2013. Inclusion criteria were: patients aged ≥ 18 years with a single, unilateral, symptomatic, radiopaque ureteric stone of 10 mm or smaller in the largest dimension located between the lower border of the sacroiliac joint and the vesico-ureteric junction. Stone expulsion rate, stone expulsion time, number of pain episodes, need for analgesics use, incidence of side effects were compared. Stone-expulsion rate in the silodosin and in the tamsulosin groups were 88% and 82%, respectively (p not significant). Mean expulsion times were 6.7 and 6.5 days in the silodosin and tamsulosin group, respectively (p not significant). Mean number of pain episodes were 1.6 and 1.7 in the silodosin and tamsulosin group, respectively (p not significant). The mean number of analgesic requirement was 0.84 and 0.9 for the silodosin and tamsulosin group, respectively (p not significant). Overall, incidence of side effects was similar in both groups. Patients taking silodosin experienced an higher incidence of retrograde ejaculation but a lower incidence of side effects related to peripheral vasodilation when compared to patients taking tamsulosin. Subgroup analysis demonstrated significantly lower mean expulsion times and pain episodes in patients with stones ≤ 5 mm in both groups. Tamsulosin and silodosin are equally effective as MET for distal ureteric stones sized 10 mm or smaller. MET with silodosin is associatd with a lower incidence of side effects related to peripheral vasodilation but an higher incidence of retrograde ejaculation when compared to tamsulosin.

  11. Honig v. Doe: the suspension and expulsion of handicapped students.

    Science.gov (United States)

    Yell, M L

    1989-09-01

    Public Law 94-142 provides for a free appropriate public education for all handicapped children, but does not address the issue of disciplining handicapped students. The result has been confusion and uncertainty, particularly concerning expulsion and suspension. The courts have been forced into this vacuum, acting as arbiters. The Supreme Court's ruling in Honig v. Doe will help to delineate the proper role of educators in the suspension and expulsion of handicapped students. This article examines that role and offers recommendations for school policies regarding the discipline of handicapped students.

  12. Development of a Hemispherical Metal Diaphragm for Single-Cycle Liquid-Metal Positive Expulsion Systems

    National Research Council Canada - National Science Library

    Gorland, Sol

    1965-01-01

    This report presents experimental results pertaining to the design and development of a metallic expulsion diaphragm for single-cycle positive expulsion of high-temperature liquid in an agravity condition...

  13. Multiple expulsions. Affective and material evictions in Calais

    Directory of Open Access Journals (Sweden)

    Francesca Ansaloni

    2017-06-01

    Full Text Available If we regard expulsions as the abrupt interruption along the territorialisation process of any body in search of refuge, we could see displaced people and migrants as those figures that have to cope with multiple expulsions until they can build a less vulnerable and precarious territory. Drawing on an ethnographic fieldwork in the makeshift camp of Calais known as the Jungle, I outline a relentless movement of expulsion-inclusion, which is both material and affective and operates on different dimensions. In the Jungle of Calais, from March 2015 to October 2016 lived thousands of people coming mainly from Afghanistan, Sudan, Ethiopia, Eritrea, and Pakistan, who created a city-like system together with volunteers from UK and France. Both the French state and the aid groups built their own territories by establishing different kind of relations with the residents of the Jungle, thus contributing to (at least temporarily stabilise or destabilise their search for a territory of their own and engaging in less visible practices of expulsion.

  14. The role of fluid migration system in hydrocarbon accumulation in Maichen Sag, Beibuwan Basin

    Science.gov (United States)

    Liu, Hongyu; Yang, Jinxiu; Wu, Feng; Chen, Wei; Liu, Qianqian

    2018-02-01

    Fluid migration system is of great significance for hydrocarbon accumulation, including the primary migration and secondary migration. In this paper, the fluid migration system is analysed in Maichen Sag using seismic, well logging and core data. Results show that many factors control the hydrocarbon migration process, including hydrocarbon generation and expulsion period from source rocks, microfractures developed in the source rocks, the connected permeable sand bodies, the vertical faults cutting into/through the source rocks and related fault activity period. The spatial and temporal combination of these factors formed an effective network for hydrocarbon expulsion and accumulation, leading to the hydrocarbon reservoir distribution at present. Generally, a better understanding of the hydrocarbon migration system can explain the present status of hydrocarbon distribution, and help select future target zones for oil and gas exploration.

  15. Chemical kinetic models for combustion of hydrocarbons and formation of nitric oxide

    Science.gov (United States)

    Jachimowski, C. J.; Wilson, C. H.

    1980-01-01

    The formation of nitrogen oxides NOx during combustion of methane, propane, and a jet fuel, JP-4, was investigated in a jet stirred combustor. The results of the experiments were interpreted using reaction models in which the nitric oxide (NO) forming reactions were coupled to the appropriate hydrocarbon combustion reaction mechanisms. Comparison between the experimental data and the model predictions reveals that the CH + N2 reaction process has a significant effect on NO formation especially in stoichiometric and fuel rich mixtures. Reaction models were assembled that predicted nitric oxide levels that were in reasonable agreement with the jet stirred combustor data and with data obtained from a high pressure (5.9 atm (0.6 MPa)), prevaporized, premixed, flame tube type combustor. The results also suggested that the behavior of hydrocarbon mixtures, like JP-4, may not be significantly different from that of pure hydrocarbons. Application of the propane combustion and nitric oxide formation model to the analysis of NOx emission data reported for various aircraft gas turbines showed the contribution of the various nitric oxide forming processes to the total NOx formed.

  16. Formation of radical cations in a model for the metabolism of aromatic hydrocarbons

    International Nuclear Information System (INIS)

    Lehner, Andreas F.; Horn, Jamie; Flesher, James W.

    2004-01-01

    To test the hypothesis that electrophilic radical cations are the major ultimate electrophilic and carcinogenic forms of benz[a]anthracene (BA), dibenz[a,h]anthracene (DBA), and benzo[a]pyrene (BP), we have focused on a chemical model of metabolism which parallels and duplicates known or potential metabolites of some polycyclic hydrocarbons formed in cells. Studies of this model system show that radical cations are hardly formed, if at all, in the case of BA or DBA but are definitely formed in the cases of the carcinogen BP as well as the non-carcinogenic hydrocarbons, pyrene and perylene. We conclude that the carcinogenicities of BA, DBA, BP, pyrene, and perylene are independent of one-electron oxidation to radical cation intermediates

  17. Formalization of hydrocarbon conversion scheme of catalytic cracking for mathematical model development

    Science.gov (United States)

    Nazarova, G.; Ivashkina, E.; Ivanchina, E.; Kiseleva, S.; Stebeneva, V.

    2015-11-01

    The issue of improving the energy and resource efficiency of advanced petroleum processing can be solved by the development of adequate mathematical model based on physical and chemical regularities of process reactions with a high predictive potential in the advanced petroleum refining. In this work, the development of formalized hydrocarbon conversion scheme of catalytic cracking was performed using thermodynamic parameters of reaction defined by the Density Functional Theory. The list of reaction was compiled according to the results of feedstock structural-group composition definition, which was done by the n-d-m-method, the Hazelvuda method, qualitative composition of feedstock defined by gas chromatography-mass spectrometry and individual composition of catalytic cracking gasoline fraction. Formalized hydrocarbon conversion scheme of catalytic cracking will become the basis for the development of the catalytic cracking kinetic model.

  18. MODELING GALACTIC EXTINCTION WITH DUST AND 'REAL' POLYCYCLIC AROMATIC HYDROCARBONS

    Energy Technology Data Exchange (ETDEWEB)

    Mulas, Giacomo; Casu, Silvia; Cecchi-Pestellini, Cesare [INAF-Osservatorio Astronomico di Cagliari, Strada n.54, Loc. Poggio dei Pini, I-09012 Capoterra (Italy); Zonca, Alberto, E-mail: gmulas@oa-cagliari.inaf.it, E-mail: silvia@oa-cagliari.inaf.it, E-mail: ccp@oa-cagliari.inaf.it, E-mail: azonca@oa-cagliari.inaf.it [Dipartimento di Fisica, Universita di Cagliari, Strada Prov.le Monserrato-Sestu Km 0.700, I-09042 Monserrato (Italy)

    2013-07-01

    We investigate the remarkable apparent variety of galactic extinction curves by modeling extinction profiles with core-mantle grains and a collection of single polycyclic aromatic hydrocarbons. Our aim is to translate a synthetic description of dust into physically well-grounded building blocks through the analysis of a statistically relevant sample of different extinction curves. All different flavors of observed extinction curves, ranging from the average galactic extinction curve to virtually 'bumpless' profiles, can be described by the present model. We prove that a mixture of a relatively small number (54 species in 4 charge states each) of polycyclic aromatic hydrocarbons can reproduce the features of the extinction curve in the ultraviolet, dismissing an old objection to the contribution of polycyclic aromatic hydrocarbons to the interstellar extinction curve. Despite the large number of free parameters (at most the 54 Multiplication-Sign 4 column densities of each species in each ionization state included in the molecular ensemble plus the 9 parameters defining the physical properties of classical particles), we can strongly constrain some physically relevant properties such as the total number of C atoms in all species and the mean charge of the mixture. Such properties are found to be largely independent of the adopted dust model whose variation provides effects that are orthogonal to those brought about by the molecular component. Finally, the fitting procedure, together with some physical sense, suggests (but does not require) the presence of an additional component of chemically different very small carbonaceous grains.

  19. Rates of chemical reaction and atmospheric heating during core debris expulsion from a pressurized vessel

    International Nuclear Information System (INIS)

    Powers, D.A.; Tarbell, W.W.; Brockman, J.E.; Pilch, M.

    1986-01-01

    Core debris may be expelled from a pressurized reactor vessel during a severe nuclear reactor accident. Experimental studies of core debris expulsion from pressurized vessels have established that the expelled material can be lofted into the atmosphere of the reactor containment as particulate 0.4 to 2 mm in diameter. These particles will vigorously react with steam and oxygen in the containment atmosphere. Data on such reactions during tests with 80 kg of expelled melt will be reported. A model of the reaction rates based on gas phase mass transport will be described and shown to account for atmospheric heating and aerosol generation observed in the tests

  20. Near omni-conductors and insulators: Alternant hydrocarbons in the SSP model of ballistic conduction

    Science.gov (United States)

    Fowler, Patrick W.; Sciriha, Irene; Borg, Martha; Seville, Victoria E.; Pickup, Barry T.

    2017-10-01

    Within the source-and-sink-potential model, a complete characterisation is obtained for the conduction behaviour of alternant π-conjugated hydrocarbons (conjugated hydrocarbons without odd cycles). In this model, an omni-conductor has a molecular graph that conducts at the Fermi level irrespective of the choice of connection vertices. Likewise, an omni-insulator is a molecular graph that fails to conduct for any choice of connections. We give a comprehensive classification of possible combinations of omni-conducting and omni-insulating behaviour for molecular graphs, ranked by nullity (number of non-bonding orbitals). Alternant hydrocarbons are those that have bipartite molecular graphs; they cannot be full omni-conductors or full omni-insulators but may conduct or insulate within well-defined subsets of vertices (unsaturated carbon centres). This leads to the definition of "near omni-conductors" and "near omni-insulators." Of 81 conceivable classes of conduction behaviour for alternants, only 14 are realisable. Of these, nine are realised by more than one chemical graph. For example, conduction of all Kekulean benzenoids (nanographenes) is described by just two classes. In particular, the catafused benzenoids (benzenoids in which no carbon atom belongs to three hexagons) conduct when connected to leads via one starred and one unstarred atom, and otherwise insulate, corresponding to conduction type CII in the near-omni classification scheme.

  1. The Role of Pharmacology in Ureteral Physiology and Expulsive Therapy

    Science.gov (United States)

    Jerde, Travis J.; Nakada, Stephen Y.

    2007-04-01

    Research in the field of ureteral physiology and pharmacology has traditionally been directed toward relaxation of ureteral spasm as a mechanism of analgesia during painful ureteral obstruction, most often stone-induced episodes. However, interest in this field has expanded greatly in recent years with the expanded use of alpha-blocker therapy for inducing stone passage, a usage now termed "medical expulsive therapy". While most clinical reports involving expulsive therapy have focused on alpha receptor or calcium channel blockade, there are diverse studies investigating pharmacological ureteral relaxation with novel agents including cyclooxygenase inhibitors, small molecule beta receptor agonists, neurokinin antagonists, and phosphodiesterase inhibitors. In addition, cutting edge molecular biology research is revealing promising potential therapeutic targets aimed at specific molecular changes that occur during the acute obstruction that accompanies stone disease. The purpose of this report is to review the use of pharmacological agents as ureteral smooth muscle relaxants clinically, and to look into the future of expulsive therapy by reviewing the available literature of ureteral physiology and pharmacology research.

  2. Modelling Poly-Aromatic Hydrocarbons "online" with the GEOS-Chem Europe and Asia regional models.

    Science.gov (United States)

    Ivatt, P.; Evans, M. J.

    2017-12-01

    Poly-Aromatic Hydrocarbons (PAHs) are carcinogens and so are restricted by international treaties. PAHs are mainly emitted into the atmosphere by domestic (heating and cooking), natural (forest fires burning), as well as some industrial processes (coke ovens). PAHs partition between the gas and particle phase (notably carbonaceous particles) based on their volatility. In recent years, interest has turned to the possible health effects of their oxidation products (both nitrogenated and oxygenated) as it has been suggested that these oxidation products may be even more carcinogenic than the parent PAHs. To increase our understanding of the processes controlling the regional concentrations of PAHs and their oxidation products an "online" PAH model has been developed within the GEOS-Chem framework. This provides for the representation of the coupled aerosol/gas phase chemistry of the parent PAH and its secondary oxidation products. Benzo[a]pyrene is used as an exemplar but the methodology is flexible and the approach can be used for any PAH species. Comparisons are made with observations and the sources of variability discussed.

  3. Reflections about the modelling of unconfined explosions of air-hydrocarbon mixtures

    International Nuclear Information System (INIS)

    Hendrickx, S.; Lannoy, A.

    1983-01-01

    To design nuclear power plants structures, an evaluation of hazards which can be induced by the industrial activities is needed. These hazards namely involve explosions of flamable air-hydrocarbon gas clouds. Such clouds can drift before ignition, and, when ignited, the generated pressure wave can cause serious damage, even far from the initial accident location. When the designs an industrial plant, the designer has to predict the overpressures capable of jeopardizing the safety functions of the plant. The analysis of real accidental explosions which have actually occurred, on the basis of a total explosion yield and the TNT equivalency concept, is a first step. Indeed, it allows a total explosion yield to be calculated, an empirical TNT equivalent of hydrocarbon to be deducted. Unfortunately, this TNT equivalency concept is scientifically not satisfying. The modelling of an unconfined air-hydrocarbon detonation can be used for safety analysis, if we assume that an unconfined explosion can be a detonation, which is unlikely. (orig./WL)

  4. Application of numerical modeling of selective NOx reduction by hydrocarbon under diesel transient conditions in consideration of hydrocarbon adsorption and desorption process

    International Nuclear Information System (INIS)

    Watanabe, Y.; Asano, A.; Banno, K.; Yokota, K.; Sugiura, M.

    2001-01-01

    A model of NO x selective reduction by hydrocarbon (HC) was developed, which takes into account the adsorption and desorption of HC. The model was applied for predicting the performance of a De-NO x catalytic reactor, working under transient conditions such as a legislative driving cycle. Diesel fuel was used as a supplemental reductant. The behavior of HC and NO x reactions and HC adsorption and desorption has been simulated successfully by our numerical approach under the transient conditions of the simulated Japanese 10-15 driving cycle. Our model is expected to optimize the design of selective diesel NO x reduction systems using a diesel fuel as a supplemental reductant

  5. Effect of turbulence models on predicting convective heat transfer to hydrocarbon fuel at supercritical pressure

    Directory of Open Access Journals (Sweden)

    Tao Zhi

    2016-10-01

    Full Text Available A variety of turbulence models were used to perform numerical simulations of heat transfer for hydrocarbon fuel flowing upward and downward through uniformly heated vertical pipes at supercritical pressure. Inlet temperatures varied from 373 K to 663 K, with heat flux ranging from 300 kW/m2 to 550 kW/m2. Comparative analyses between predicted and experimental results were used to evaluate the ability of turbulence models to respond to variable thermophysical properties of hydrocarbon fuel at supercritical pressure. It was found that the prediction performance of turbulence models is mainly determined by the damping function, which enables them to respond differently to local flow conditions. Although prediction accuracy for experimental results varied from condition to condition, the shear stress transport (SST and launder and sharma models performed better than all other models used in the study. For very small buoyancy-influenced runs, the thermal-induced acceleration due to variations in density lead to the impairment of heat transfer occurring in the vicinity of pseudo-critical points, and heat transfer was enhanced at higher temperatures through the combined action of four thermophysical properties: density, viscosity, thermal conductivity and specific heat. For very large buoyancy-influenced runs, the thermal-induced acceleration effect was over predicted by the LS and AB models.

  6. Giant seafloor craters formed by hydrate-controlled large-scale methane expulsion from the Arctic seafloor after ice sheet retreat

    Science.gov (United States)

    Andreassen, K.; Hubbard, A.; Patton, H.; Vadakkepuliyambatta, S.; Winsborrow, M.; Plaza-Faverola, A. A.; Serov, P.

    2017-12-01

    Large-scale methane releases from thawing Arctic gas hydrates is a major concern, yet the processes and fluxes involved remain elusive. We present geophysical data indicating two contrasting processes of natural methane emissions from the seafloor of the northern Barents Sea, Polar North Atlantic. Abundant gas flares, acoustically imaged in the water column reveal slow, gradual release of methane bubbles, a process that is commonly documented from nearby areas, elsewhere in the Arctic and along continental margins worldwide. Conversely, giant craters across the study area indicate a very different process. We propose that these are blow-out craters, formed through large-scale, abrupt methane expulsion induced when gas hydrates destabilized after the Barents Sea Ice Sheet retreated from the area. The data reveal over 100 giant seafloor craters within an area of 440 km2. These are up to 1000 m in diameter, 30 m deep and with a semi-circular to elliptical shape. We also identified numerous large seafloor mounds, which we infer to have formed by the expansion of gas hydrate accumulations within the shallow subsurface, so-called gas hydrate pingos. These are up to 1100 m wide and 20 m high. Smaller craters and mounds < 200 m wide and with varying relief are abundant across the study site. The empirical observations and analyses are combined with numerical modelling of ice sheet, isostatic and gas hydrate evolution and indicate that during glaciation, natural gas migrating from underlying hydrocarbon reservoirs was stored as subglacial gas hydrates. On ice sheet retreat, methane from these hydrate reservoirs and underlying free gas built up and abruptly released, forming the giant mounds and craters observed in the study area today. Petroleum basins are abundant beneath formerly and presently glaciated regions. We infer that episodes of subglacial sequestration of gas hydrates and underlying free gas and subsequent abrupt expulsions were common and widespread throughout

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

    Science.gov (United States)

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

    2014-08-01

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

  8. Assessment of atmospheric distribution of polychlorinated biphenyls and polycyclic aromatic hydrocarbons using polyparameter model

    Directory of Open Access Journals (Sweden)

    Turk-Sekulić Maja M.

    2011-01-01

    Full Text Available Results of partial or total destruction of industrial plants, military targets, infrastructure, uncontrolled fires and explosions during the conflict period from 1991 to 1999, at the area of Western Balkans, were large amounts of hazardous organic matter that have been generated and emitted in the environment. In order to assess gas/particle partition of seven EPA polychlorinated biphenyls and sixteen EPA polycyclic aromatic hydrocarbons, twenty air samples have been collected at six urban, industrial and highly contaminated localities in Vojvodina. Hi-Vol methodology has been used for collecting ambiental air samples, that simultaneously collects gaseous and particulate phase with polyurethane foam filters (PUF and glass fiber filters (GFF. PUF and GFF filters have been analyzed, and concentration levels of gaseous PCBs and PAHs molecules in gaseous and particulate phase were obtained, converted and expressed through fraction of individual compounds sorbed onto particulate phase of the sample, in total detected quantity. Experimentally gained gas/particle partitioning values of PCBs and PAHs molecules have been compared with PP-LFER model estimated values. Significant deviation has been noticed during comparative analysis of estimated polyparameter model values for complete set of seven PCBs congeners. Much better agreement of experimental and estimated values is for polycyclic aromatic hydrocarbons, especially for molecules with four rings. These results are in a good correlation with literature data where polyparameter model has been used for predicting gas/particle partition of studied group of organic molecules.

  9. Novel extension of the trap model for electrons in liquid hydrocarbons

    International Nuclear Information System (INIS)

    Jamal, M.A.; Watt, D.E.

    1981-01-01

    A novel extension for the trap model of electron mobilities in liquid hydrocarbons is described. The new model assumes: (a) two main types of electron trap exist in liquid hydrocarbons, one is deep and the second is shallow; (b) these traps are the same in all liquid alkanes. The difference in electron mobilities in different alkanes is accounted for by the difference in the frequency of electron trapping in each state. The probability of trapping in each state has been evaluated from the known structures of the normal alkanes. Electron mobilities in normal alkanes (C 3 -C 10 ) show a very good correlation with the probability of trapping in deep traps, suggesting that the C-C bonds are the main energy sinks of the electron. A mathematical formula which expresses the electron mobility in terms of the probability of trapping in deep traps has been found from the Arrhenius relationship between electron mobilities and probability of trapping. The model has been extended for branched alkanes and the relatively high electron mobilities in globular alkanes has been explained by the fact that each branch provides some degree of screening to the skeleton structure of the molecule resulting in reduction of the probability of electron interaction with the molecular skeleton. (author)

  10. A Geochemical Model of Fluids and Mineral Interactions for Deep Hydrocarbon Reservoirs

    Directory of Open Access Journals (Sweden)

    Jun Li

    2017-01-01

    Full Text Available A mutual solubility model for CO2-CH4-brine systems is constructed in this work as a fundamental research for applications of deep hydrocarbon exploration and production. The model is validated to be accurate for wide ranges of temperature (0–250°C, pressure (1–1500 bar, and salinity (NaCl molality from 0 to more than 6 mole/KgW. Combining this model with PHREEQC functionalities, CO2-CH4-brine-carbonate-sulfate equilibrium is calculated. From the calculations, we conclude that, for CO2-CH4-brine-carbonate systems, at deeper positions, magnesium is more likely to be dissolved in aqueous phase and calcite can be more stable than dolomite and, for CO2-CH4-brine-sulfate systems, with a presence of CH4, sulfate ions are likely to be reduced to S2− and H2S in gas phase could be released after S2− saturated in the solution. The hydrocarbon “souring” process could be reproduced from geochemical calculations in this work.

  11. A simple one-step chemistry model for partially premixed hydrocarbon combustion

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez-Tarrazo, Eduardo [Instituto Nacional de Tecnica Aeroespacial, Madrid (Spain); Sanchez, Antonio L. [Area de Mecanica de Fluidos, Universidad Carlos III de Madrid, Leganes 28911 (Spain); Linan, Amable [ETSI Aeronauticos, Pl. Cardenal Cisneros 3, Madrid 28040 (Spain); Williams, Forman A. [Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, CA 92093-0411 (United States)

    2006-10-15

    This work explores the applicability of one-step irreversible Arrhenius kinetics with unity reaction order to the numerical description of partially premixed hydrocarbon combustion. Computations of planar premixed flames are used in the selection of the three model parameters: the heat of reaction q, the activation temperature T{sub a}, and the preexponential factor B. It is seen that changes in q with equivalence ratio f need to be introduced in fuel-rich combustion to describe the effect of partial fuel oxidation on the amount of heat released, leading to a universal linear variation q(f) for f>1 for all hydrocarbons. The model also employs a variable activation temperature T{sub a}(f) to mimic changes in the underlying chemistry in rich and very lean flames. The resulting chemistry description is able to reproduce propagation velocities of diluted and undiluted flames accurately over the whole flammability limit. Furthermore, computations of methane-air counterflow diffusion flames are used to test the proposed chemistry under nonpremixed conditions. The model not only predicts the critical strain rate at extinction accurately but also gives near-extinction flames with oxygen leakage, thereby overcoming known predictive limitations of one-step Arrhenius kinetics. (author)

  12. Artificial neural network for modeling the extraction of aromatic hydrocarbons from lube oil cuts

    Energy Technology Data Exchange (ETDEWEB)

    Mehrkesh, A.H.; Hajimirzaee, S. [Islamic Azad University, Majlesi Branch, Isfahan (Iran, Islamic Republic of); Hatamipour, M.S.; Tavakoli, T. [Department of Chemical Engineering, University of Isfahan, Isfahan (Iran, Islamic Republic of)

    2011-03-15

    An artificial neural network (ANN) approach was used to obtain a simulation model to predict the rotating disc contactor (RDC) performance during the extraction of aromatic hydrocarbons from lube oil cuts, to produce a lubricating base oil using furfural as solvent. The field data used for training the ANN model was obtained from a lubricating oil production company. The input parameters of the ANN model were the volumetric flow rates of feed and solvent, the temperatures of feed and solvent, and the disc rotation rate. The output parameters were the volumetric flow rate of the raffinate phase and the extraction yield. In this study, a feed-forward multi-layer perceptron neural network was successfully used to demonstrate the complex relationship between the mentioned input and output parameters. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  13. Aromatic hydrocarbons

    International Nuclear Information System (INIS)

    Roder, M.

    1985-01-01

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

  14. Quench pressure, thermal expulsion, and normal zone propagation in internally cooled superconductors

    International Nuclear Information System (INIS)

    Dresner, L.

    1988-01-01

    When a nonrecovering normal zone appears in an internally cooled superconductor, the pressure in the conductor rises, helium is expelled from its ends, and the normal zone grows in size. This paper presents a model of these processes that allows calculation of the pressure, the expulsion velocity, and the propagation velocity with simple formulas. The model is intended to apply to conductors such as the cable-in-conduit conductor of the Westinghouse LCT (WH-LCT) coil, the helium volumes of which have very large length-to-diameter ratios (3 /times/ 10 5 ). The predictions of the model agree with the rather limited data available from propagation experiments carried out on the WH-LCT coil. 3 refs., 1 fig

  15. Non-Invasive Airway Cleansing with Application of Expulsion Effect of HFJV (High Frequency Jet Ventilation

    Directory of Open Access Journals (Sweden)

    A. Hermely

    2010-01-01

    Full Text Available The aim of this study was to demonstrate the effectiveness of the use of expulsion and impulsion nozzle high frequency ventilation (VFDV for cleansing respiratory system during long-term mechanical ventilation. Material and methods. Retrospective study. In the group of 198 patients presenting its own procedures and the application of inpulsive and expulsive effect of the nozzle frequency ventilation (VFDV for cleansing and maintaining a patent airway. They used high frequency jet ventilation with the possibility of expulsion and epulsion programming and assessed a total of over 8000 expulsion procedures. Changes in lung mechanics, hemodynamics, effectiveness of expulsion and the need for suction beforeexpulsion and in regular application of VFDV were monitored. Results. We statistically compared and evaluated the effectiveness of expulsion in the VFDV group of 198 patients on long-term UVP, which was effective in average of 94.9% of patients. The impact of expulsion regime on circulatory, ventilation systems and gas exchange in the lungs, including lung mechanics, were analyzed. The authors found that the application of VFDV had a substantial and statistically significant effect on hemodynamics. Application of expulsion and lavage (a technique is described statistically significantly reduced airway resistance Raw (p<0.01 and improved the levels of lung static compliance (p<0.01 compared with the prior expulsion. Changes in blood gases during the expulsion itself did not have a major impact on gas exchange in the lungs or on the pH in this group, but there was a statistically significant increase in PaO2 (p<0.05. A key finding was that when comparing the number of manipulations in the airways (suction, a radical reduction in the number of pumping was observed, if expulsion was used regularly. A statistically significant difference in the application of expulsion was detected when compared to most groups of patients (p<0.01. The number of

  16. A new HYSYS model for underground gasification of hydrocarbons under hydrothermal conditions

    KAUST Repository

    Alshammari, Y.M.

    2014-08-01

    A new subsurface process model was developed using the ASPEN HYSYS simulation environment to analyse the process energy and gasification efficiency at steady-state equilibrium conditions. Injection and production wells were simulated using the HYSYS pipe flow utilities which makes use of the Beggs and Brill flow correlation applicable for vertical pipes. The downhole reservoir hydrothermal reactions were assumed to be in equilibrium, and hence, the Gibbs reactor was used. It was found that high W/C ratios and low O/C ratios are required to maximise gasification efficiency at a constant hydrocarbon feed flowrate, while the opposite is true for the energy efficiency. This occurs due to the dependence of process energy efficiency on the gas pressure and temperature at surface, while the gasification efficiency depends on the gas composition which is determined by the reservoir reaction conditions which affects production distribution. Another effect of paramount importance is the increase in reservoir production rate which was found to directly enhance both energy and gasification efficiency showing conditions where the both efficiencies are theoretically maximised. Results open new routes for techno-economic assessment of commercial implementation of underground gasification of hydrocarbons. © 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

  17. Removal of polycyclic aromatic hydrocarbons in soil spiked with model mixtures of petroleum hydrocarbons and heterocycles using biosurfactants from Rhodococcus ruber IEGM 231.

    Science.gov (United States)

    Ivshina, Irina; Kostina, Ludmila; Krivoruchko, Anastasiya; Kuyukina, Maria; Peshkur, Tatyana; Anderson, Peter; Cunningham, Colin

    2016-07-15

    Removal of polycyclic aromatic hydrocarbons (PAHs) in soil using biosurfactants (BS) produced by Rhodococcus ruber IEGM 231 was studied in soil columns spiked with model mixtures of major petroleum constituents. A crystalline mixture of single PAHs (0.63g/kg), a crystalline mixture of PAHs (0.63g/kg) and polycyclic aromatic sulfur heterocycles (PASHs), and an artificially synthesized non-aqueous phase liquid (NAPL) containing PAHs (3.00g/kg) dissolved in alkanes C10-C19 were used for spiking. Percentage of PAH removal with BS varied from 16 to 69%. Washing activities of BS were 2.5 times greater than those of synthetic surfactant Tween 60 in NAPL-spiked soil and similar to Tween 60 in crystalline-spiked soil. At the same time, amounts of removed PAHs were equal and consisted of 0.3-0.5g/kg dry soil regardless the chemical pattern of a model mixture of petroleum hydrocarbons and heterocycles used for spiking. UV spectra for soil before and after BS treatment were obtained and their applicability for differentiated analysis of PAH and PASH concentration changes in remediated soil was shown. The ratios A254nm/A288nm revealed that BS increased biotreatability of PAH-contaminated soils. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. S/O modeling technique for optimal containment of light hydrocarbons in contaminated unconfined aquifers

    International Nuclear Information System (INIS)

    Cooper, G.S. Jr.; Kaluarachchi, J.J.; Peralta, R.C.

    1993-01-01

    An innovative approach is presented to minimize pumping for immobilizing a floating plume of a light non-aqueous phase liquid (LNAPL). The best pumping strategy is determined to contain the free oil product and provide for gradient control of the water table. This approach combined detailed simulation, statistical analysis, and optimization. This modeling technique uses regression equations that describe system response to variable pumping stimuli. The regression equations were developed from analysis of systematically performed simulations of multiphase flow in an areal region of an unconfined aquifer. Simulations were performed using ARMOS, a finite element model. ARMOS can be used to simulate a spill, leakage from subsurface storage facilities and recovery of hydrocarbons from trenches or pumping wells to design remediation schemes

  19. Use of extinction and reinforcement to increase food consumption and reduce expulsion.

    OpenAIRE

    Coe, D A; Babbitt, R L; Williams, K E; Hajimihalis, C; Snyder, A M; Ballard, C; Efron, L A

    1997-01-01

    Extinction and reinforcement contingencies were used to treat 2 children with feeding disorders. Positive reinforcement and avoidance extinction effectively increased food acceptance but also increased food expulsion. Reduced expulsion and increased swallowing were achieved by repeated presentation of expelled food, a second extinction component

  20. Assessing the polycyclic aromatic hydrocarbon (PAH) pollution of urban stormwater runoff: a dynamic modeling approach.

    Science.gov (United States)

    Zheng, Yi; Lin, Zhongrong; Li, Hao; Ge, Yan; Zhang, Wei; Ye, Youbin; Wang, Xuejun

    2014-05-15

    Urban stormwater runoff delivers a significant amount of polycyclic aromatic hydrocarbons (PAHs), mostly of atmospheric origin, to receiving water bodies. The PAH pollution of urban stormwater runoff poses serious risk to aquatic life and human health, but has been overlooked by environmental modeling and management. This study proposed a dynamic modeling approach for assessing the PAH pollution and its associated environmental risk. A variable time-step model was developed to simulate the continuous cycles of pollutant buildup and washoff. To reflect the complex interaction among different environmental media (i.e. atmosphere, dust and stormwater), the dependence of the pollution level on antecedent weather conditions was investigated and embodied in the model. Long-term simulations of the model can be efficiently performed, and probabilistic features of the pollution level and its risk can be easily determined. The applicability of this approach and its value to environmental management was demonstrated by a case study in Beijing, China. The results showed that Beijing's PAH pollution of road runoff is relatively severe, and its associated risk exhibits notable seasonal variation. The current sweeping practice is effective in mitigating the pollution, but the effectiveness is both weather-dependent and compound-dependent. The proposed modeling approach can help identify critical timing and major pollutants for monitoring, assessing and controlling efforts to be focused on. The approach is extendable to other urban areas, as well as to other contaminants with similar fate and transport as PAHs. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Improved predictive model for n-decane kinetics across species, as a component of hydrocarbon mixtures.

    Science.gov (United States)

    Merrill, E A; Gearhart, J M; Sterner, T R; Robinson, P J

    2008-07-01

    n-Decane is considered a major component of various fuels and industrial solvents. These hydrocarbon products are complex mixtures of hundreds of components, including straight-chain alkanes, branched chain alkanes, cycloalkanes, diaromatics, and naphthalenes. Human exposures to the jet fuel, JP-8, or to industrial solvents in vapor, aerosol, and liquid forms all have the potential to produce health effects, including immune suppression and/or neurological deficits. A physiologically based pharmacokinetic (PBPK) model has previously been developed for n-decane, in which partition coefficients (PC), fitted to 4-h exposure kinetic data, were used in preference to measured values. The greatest discrepancy between fitted and measured values was for fat, where PC values were changed from 250-328 (measured) to 25 (fitted). Such a large change in a critical parameter, without any physiological basis, greatly impedes the model's extrapolative abilities, as well as its applicability for assessing the interactions of n-decane or similar alkanes with other compounds in a mixture model. Due to these limitations, the model was revised. Our approach emphasized the use of experimentally determined PCs because many tissues had not approached steady-state concentrations by the end of the 4-h exposures. Diffusion limitation was used to describe n-decane kinetics for the brain, perirenal fat, skin, and liver. Flow limitation was used to describe the remaining rapidly and slowly perfused tissues. As expected from the high lipophilicity of this semivolatile compound (log K(ow) = 5.25), sensitivity analyses showed that parameters describing fat uptake were next to blood:air partitioning and pulmonary ventilation as critical in determining overall systemic circulation and uptake in other tissues. In our revised model, partitioning into fat took multiple days to reach steady state, which differed considerably from the previous model that assumed steady-state conditions in fat at 4 h post

  2. Effect of concentration gradients on biodegradation in bench-scale sand columns with HYDRUS modeling of hydrocarbon transport and degradation.

    Science.gov (United States)

    Horel, Agota; Schiewer, Silke; Misra, Debasmita

    2015-09-01

    The present research investigated to what extent results obtained in small microcosm experiments can be extrapolated to larger settings with non-uniform concentrations. Microbial hydrocarbon degradation in sandy sediments was compared for column experiments versus homogenized microcosms with varying concentrations of diesel, Syntroleum, and fish biodiesel as contaminants. Syntroleum and fish biodiesel had higher degradation rates than diesel fuel. Microcosms showed significantly higher overall hydrocarbon mineralization percentages (p transport and degradation of the investigated fuels in vadose zone conditions similar to those in laboratory column experiments. The numerical model was used to evaluate the impact of different degradation rate constants from microcosm versus column experiments.

  3. A Model-Based Analysis of Chemical and Temporal Patterns of Cuticular Hydrocarbons in Male Drosophila melanogaster

    Science.gov (United States)

    Kent, Clement; Azanchi, Reza; Smith, Ben; Chu, Adrienne; Levine, Joel

    2007-01-01

    Drosophila Cuticular Hydrocarbons (CH) influence courtship behaviour, mating, aggregation, oviposition, and resistance to desiccation. We measured levels of 24 different CH compounds of individual male D. melanogaster hourly under a variety of environmental (LD/DD) conditions. Using a model-based analysis of CH variation, we developed an improved normalization method for CH data, and show that CH compounds have reproducible cyclic within-day temporal patterns of expression which differ between LD and DD conditions. Multivariate clustering of expression patterns identified 5 clusters of co-expressed compounds with common chemical characteristics. Turnover rate estimates suggest CH production may be a significant metabolic cost. Male cuticular hydrocarbon expression is a dynamic trait influenced by light and time of day; since abundant hydrocarbons affect male sexual behavior, males may present different pheromonal profiles at different times and under different conditions. PMID:17896002

  4. A model-based analysis of chemical and temporal patterns of cuticular hydrocarbons in male Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Clement Kent

    Full Text Available Drosophila Cuticular Hydrocarbons (CH influence courtship behaviour, mating, aggregation, oviposition, and resistance to desiccation. We measured levels of 24 different CH compounds of individual male D. melanogaster hourly under a variety of environmental (LD/DD conditions. Using a model-based analysis of CH variation, we developed an improved normalization method for CH data, and show that CH compounds have reproducible cyclic within-day temporal patterns of expression which differ between LD and DD conditions. Multivariate clustering of expression patterns identified 5 clusters of co-expressed compounds with common chemical characteristics. Turnover rate estimates suggest CH production may be a significant metabolic cost. Male cuticular hydrocarbon expression is a dynamic trait influenced by light and time of day; since abundant hydrocarbons affect male sexual behavior, males may present different pheromonal profiles at different times and under different conditions.

  5. Improved bioavailability and biodegradation of a model polyaromatic hydrocarbon by a biosurfactant producing bacterium of marine origin.

    Science.gov (United States)

    Das, Palashpriya; Mukherjee, Soumen; Sen, Ramkrishna

    2008-07-01

    Polyaromatic hydrocarbons (PAHs) are organic pollutants mostly derived from the processing and combustion of fossil fuels and cause human health hazards. In the present study a marine biosurfactant producing strain of Bacillus circulans was used to increase the bioavailability and consequent degradation of a model polyaromatic hydrocarbon, anthracene. Although the organism could not utilize anthracene as the sole carbon source, it showed better growth and biosurfactant production in an anthracene supplemented glycerol mineral salts medium (AGlyMSM) compared to a normal glycerol mineral salts medium (GlyMSM). The biosurfactant product showed high degree of emulsification of various hydrocarbons. Analysis by gas chromatography (GC), high performance thin layer chromatography (HPTLC) and Fourier transform infrared spectroscopy (FTIR) showed that the biosurfactant could effectively entrap and solubilize PAH. Thin layer chromatographic analysis showed that anthracene was utilized as a carbon substrate for the production of biosurfactant. Thus organic pollutant anthracene was metabolized and converted to biosurfactants facilitating its own bioremediation.

  6. Modeling unburned hydrocarbon formation due to absorption/desorption processes into the wall oil film

    International Nuclear Information System (INIS)

    Shih, L.K.; Assanis, D.N.

    1992-01-01

    This paper reports that as a result of continuing air pollution problems, very stringent regulations are being enforced to control emissions of unburned hydrocarbons (HC) from premixed-charge, spark-ignition engines. A number of attempts have been reported on modeling sources of HC emissions using various analytical tools. Over the past decade, the development of multi-dimensional reacting flow codes has advanced considerably. Perhaps the most widely used multi-dimensional engine simulation code is KIVA-II, which was developed at Lost Alamos National Laboratory. The ability to deal with moving boundary conditions caused by the piston movement is built in this code. This code also includes models for turbulent fluid flow, turbulent interaction between spray drops and gas, heat transfer, chemical reaction, and fuel spray. A standard k-ε turbulence model is used for gas flow. The fuel spray model is based on the stochastic particle technique, and includes sub-models for droplet injection, breakup, collision and coalescence, and evaporation

  7. Optimization of operating conditions in oxidation of dibenzothiophene in the light hydrocarbon model

    Directory of Open Access Journals (Sweden)

    Akbari Azam

    2014-01-01

    Full Text Available In this research, the effects of process variables on the efficiency and mechanism of dibenzothiophene oxidation in formicacid/H2O2 system for deep desulfurization of a light hydrocarbon model were systematically studied by statistical modelling and optimization using response surface methodology and implementing the central composite design. A quadratic regression model was developed to predict the yield of sulfur oxidation as the model response. The model indicated that temperature was the most significant effective factor and suggested an important interaction between temperature and H2O2/sulfur ratio; at temperatures above 56°C, more excess oxidant was necessary because of instability of active peroxo intermediates and loss of H2O2 due to thermal decomposition. In contrast, the water hindrance effect of H2O2 aqueous solution in desulfurization progress was more significant at temperatures bellow 56°C. In the optimization process, minimizing H2O2/sulfur ratio and catalyst consumption for maximum yield of desulfurization was economically considerable. The optimal condition was obtained at temperature of 57 °C, H2O2/sulfur ratio of 2.5 mol/mol and catalyst dosage of 0.82 mL in 50 mL solution of DBT in n-hexane leading to a maximum oxidation yield of 95% after 1 hour reaction. Good agreement between predicted and experimental results (less than 4% error was found.

  8. Model studies for evaluating the acute neurobehavioral effects of complex hydrocarbon solvents. I. Validation of methods with ethanol

    NARCIS (Netherlands)

    McKee, R.H.; Lammers, J.H.C.M.; Hoogendijk, E.M.G.; Emmen, H.H.; Muijser, H.; Barsotti, D.A.; Owen, D.E.; Kulig, B.M.

    2006-01-01

    As a preliminary step to evaluating the acute neurobehavioral effects of hydrocarbon solvents and to establish a working model for extrapolating animal test data to humans, joint neurobehavioral/toxicokinetic studies were conducted which involved administering ethanol to rats and volunteers. The

  9. Degradation of polycyclic aromatic hydrocarbons : model simulation for bioavailability and biodegradation

    Energy Technology Data Exchange (ETDEWEB)

    Owabor, C.N.; Ogbeide, S.E. [Benin Univ. (Nigeria). Dept. of Chemical Engineering; Susu, A.A. [Lagos Univ. (Nigeria). Dept. of Chemical Engineering

    2010-04-15

    Research has indicated that the biodegradation of polycyclic aromatic hydrocarbons (PAHs) is influenced by the molecular size of the PAHs as well as by soil properties. This study presented a model for a 1-D convective-dispersive solute transport in a soil matrix. The model was designed to consider the gas-liquid interface film and the biofilm between the liquid and solid interface as well as to account for interparticle; intraparticle, and interphase mass transport. A soil microcosm reactor was used to evaluate substrate bioavailability and biodegradation in a contaminated aqueous solids system. The numerical model involved the discretization of depth, radial distance, and time into mesh or grid points with constant intervals. Dimensionless variables were defined using a backward finite difference (BFD) method. Results of the study suggested that PAH occlusion occurred in the micropores of the soil particle. The non-steady state model adequately predicted the concentration profiles of PAHs within the soil matrix. 26 refs., 5 tabs., 7 figs.

  10. Parsing pyrogenic polycyclic aromatic hydrocarbons: forensic chemistry, receptor models, and source control policy.

    Science.gov (United States)

    O'Reilly, Kirk T; Pietari, Jaana; Boehm, Paul D

    2014-04-01

    A realistic understanding of contaminant sources is required to set appropriate control policy. Forensic chemical methods can be powerful tools in source characterization and identification, but they require a multiple-lines-of-evidence approach. Atmospheric receptor models, such as the US Environmental Protection Agency (USEPA)'s chemical mass balance (CMB), are increasingly being used to evaluate sources of pyrogenic polycyclic aromatic hydrocarbons (PAHs) in sediments. This paper describes the assumptions underlying receptor models and discusses challenges in complying with these assumptions in practice. Given the variability within, and the similarity among, pyrogenic PAH source types, model outputs are sensitive to specific inputs, and parsing among some source types may not be possible. Although still useful for identifying potential sources, the technical specialist applying these methods must describe both the results and their inherent uncertainties in a way that is understandable to nontechnical policy makers. The authors present an example case study concerning an investigation of a class of parking-lot sealers as a significant source of PAHs in urban sediment. Principal component analysis is used to evaluate published CMB model inputs and outputs. Targeted analyses of 2 areas where bans have been implemented are included. The results do not support the claim that parking-lot sealers are a significant source of PAHs in urban sediments. © 2013 SETAC.

  11. Validation of groundwater modelling for DDT and petroleum hydrocarbons at Border Pump Station and Rainy Hollow, northern British Columbia

    International Nuclear Information System (INIS)

    Dodd, M.; Bright, D.; Hartshorne, B.

    2001-01-01

    Border Station and Rainy Hollow are inactive booster pumping stations along the Haines-Fairbanks Pipeline in northern British Columbia. An emergency site cleanup was conducted in 1994 after canisters containing DDT [1,1,1-trichloro-2,2-bis(p-chloro phenyl)ethane] were discovered buried in a dump. A detailed site investigation showed that hydrocarbons and DDT were present in soil and groundwater. The major contaminants of concern were DDTs in surface soil, DDTs in subsurface soils and groundwater, and light hydrocarbons in subsurface soils and groundwater. Remedial action took place in the summer of 1997. The canisters, along with soils and other contaminated materials, were excavated and shipped off-site for disposal. A conceptual groundwater model was developed to predict future contaminant releases to the nearby Klehini River. A monitoring program was initiated to validate the groundwater model. From 1997 to 2000, the groundwater was sampled analyzed annually for DDT, metals and hydrocarbons. Results indicated a striking overall consistency in the concentrations of DDT and hydrocarbons in both groundwater and surface water samples, confirming the validity of the 1996 model predictions. 12 refs., 1 tab., 4 figs

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

    Directory of Open Access Journals (Sweden)

    Lehner F. K.

    2006-11-01

    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

  13. Receptor modeling for source apportionment of polycyclic aromatic hydrocarbons in urban atmosphere.

    Science.gov (United States)

    Singh, Kunwar P; Malik, Amrita; Kumar, Ranjan; Saxena, Puneet; Sinha, Sarita

    2008-01-01

    This study reports source apportionment of polycyclic aromatic hydrocarbons (PAHs) in particulate depositions on vegetation foliages near highway in the urban environment of Lucknow city (India) using the principal components analysis/absolute principal components scores (PCA/APCS) receptor modeling approach. The multivariate method enables identification of major PAHs sources along with their quantitative contributions with respect to individual PAH. The PCA identified three major sources of PAHs viz. combustion, vehicular emissions, and diesel based activities. The PCA/APCS receptor modeling approach revealed that the combustion sources (natural gas, wood, coal/coke, biomass) contributed 19-97% of various PAHs, vehicular emissions 0-70%, diesel based sources 0-81% and other miscellaneous sources 0-20% of different PAHs. The contributions of major pyrolytic and petrogenic sources to the total PAHs were 56 and 42%, respectively. Further, the combustion related sources contribute major fraction of the carcinogenic PAHs in the study area. High correlation coefficient (R2 > 0.75 for most PAHs) between the measured and predicted concentrations of PAHs suggests for the applicability of the PCA/APCS receptor modeling approach for estimation of source contribution to the PAHs in particulates.

  14. Model Titan atmospheric hydrocarbon analysis by Ion Mobility Spectrometry in dry helium

    International Nuclear Information System (INIS)

    Kojiro, D.R.; Stimac, R.M.; Wernlund, R.F.; Cohen, M.J.

    1990-01-01

    Ion Mobility Spectrometry (IMS) is one analytical technique being investigated for the in situ analysis of the atmosphere of Titan. Any hydrocarbon ions that may form react immediately, in microseconds, with the high concentration of water vapor normally present in conventional IMS. By reducing the water concentration to the parts-per-billion range, the lifetime of the hydrocarbon ions may be increased to the milliseconds required for measurement. At low water level concentrations, other species may become the reactant ion. This study focuses on IMS analysis of expected Titan atmospheric hydrocarbons under very dry, low water concentration conditions

  15. Numerical investigation of CO2 storage in hydrocarbon field using a geomechanical-fluid coupling model

    Directory of Open Access Journals (Sweden)

    Guang Li

    2016-09-01

    Full Text Available Increasing pore pressure due to CO2 injection can lead to stress and strain changes of the reservoir. One of the safely standards for long term CO2 storage is whether stress and strain changes caused by CO2 injection will lead to irreversible mechanical damages of the reservoir and impact the integrity of caprock which could lead to CO2 leakage through previously sealing structures. Leakage from storage will compromise both the storage capacity and the perceived security of the project, therefore, a successful CO2 storage project requires large volumes of CO2 to be injected into storage site in a reliable and secure manner. Yougou hydrocarbon field located in Orods basin was chosen as storage site based on it's stable geological structure and low leakage risks. In this paper, we present a fluid pressure and stress-strain variations analysis for CO2 geological storage based on a geomechanical-fluid coupling model. Using nonlinear elasticity theory to describe the geomechanical part of the model, while using the Darcy's law to describe the fluid flow. Two parts are coupled together using the poroelasticity theory. The objectives of our work were: 1 evaluation of the geomechanical response of the reservoir to different CO2 injection scenarios. 2 assessment of the potential leakage risk of the reservoir caused by CO2 injection.

  16. Polygonal current models for polycyclic aromatic hydrocarbons and graphene sheets of various shapes.

    Science.gov (United States)

    Pelloni, Stefano; Lazzeretti, Paolo

    2018-01-05

    Assuming that graphene is an "infinite alternant" polycyclic aromatic hydrocarbon resulting from tessellation of a surface by only six-membered carbon rings, planar fragments of various size and shape (hexagon, triangle, rectangle, and rhombus) have been considered to investigate their response to a magnetic field applied perpendicularly. Allowing for simple polygonal current models, the diatropicity of a series of polycyclic textures has been reliably determined by comparing quantitative indicators, the π-electron contribution to I B , the magnetic field-induced current susceptibility of the peripheral circuit, to ξ∥ and to σ∥(CM)=-NICS∥(CM), respectively the out-of-plane components of the magnetizability tensor and of the magnetic shielding tensor at the center of mass. Extended numerical tests and the analysis based on the polygonal model demonstrate that (i) ξ∥ and σ∥(CM) yield inadequate and sometimes erroneous measures of diatropicity, as they are heavily flawed by spurious geometrical factors, (ii) I B values computed by simple polygonal models are valid quantitative indicators of aromaticity on the magnetic criterion, preferable to others presently available, whenever current susceptibility cannot be calculated ab initio as a flux integral, (iii) the hexagonal shape is the most effective to maximize the strength of π-electron currents over the molecular perimeter, (iv) the edge current strength of triangular and rhombic graphene fragments is usually much smaller than that of hexagonal ones, (v) doping by boron and nitrogen nuclei can regulate and even inhibit peripheral ring currents, (vi) only for very large rectangular fragments can substantial current strengths be expected. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

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

    Science.gov (United States)

    Peel, Frank J.

    2014-09-01

    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.

  18. Evaluation of the phototoxicity of unsubstituted and alkylated polycyclic aromatic hydrocarbons to mysid shrimp (Americamysis bahia): Validation of predictive models.

    Science.gov (United States)

    Finch, Bryson E; Marzooghi, Solmaz; Di Toro, Dominic M; Stubblefield, William A

    2017-08-01

    Crude oils are composed of an assortment of hydrocarbons, some of which are polycyclic aromatic hydrocarbons (PAHs). Polycyclic aromatic hydrocarbons are of particular interest due to their narcotic and potential phototoxic effects. Several studies have examined the phototoxicity of individual PAHs and fresh and weathered crude oils, and several models have been developed to predict PAH toxicity. Fingerprint analyses of oils have shown that PAHs in crude oils are predominantly alkylated. However, current models for estimating PAH phototoxicity assume toxic equivalence between unsubstituted (i.e., parent) and alkyl-substituted compounds. This approach may be incorrect if substantial differences in toxic potency exist between unsubstituted and substituted PAHs. The objective of the present study was to examine the narcotic and photo-enhanced toxicity of commercially available unsubstituted and alkylated PAHs to mysid shrimp (Americamysis bahia). Data were used to validate predictive models of phototoxicity based on the highest occupied molecular orbital-lowest unoccupied molecular orbital (HOMO-LUMO) gap approach and to develop relative effect potencies. Results demonstrated that photo-enhanced toxicity increased with increasing methylation and that phototoxic PAH potencies vary significantly among unsubstituted compounds. Overall, predictive models based on the HOMO-LUMO gap were relatively accurate in predicting phototoxicity for unsubstituted PAHs but are limited to qualitative assessments. Environ Toxicol Chem 2017;36:2043-2049. © 2017 SETAC. © 2017 SETAC.

  19. Can tamsulosin facilitate expulsion of ureteral stones? A meta-analysis of randomized controlled trials.

    Science.gov (United States)

    Fan, Bo; Yang, Deyong; Wang, Jianbo; Che, Xiangyu; Li, Xiancheng; Wang, Lina; Chen, Feng; Wang, Tiezheng; Song, Xishuang

    2013-08-01

    To determine the efficacy and safety of the adrenergic alpha-antagonist tamsulosin in facilitating ureteral stones expulsion. A literature search was carried out using the PubMed database, Medline via Ovid, Embase and the Cochrane Library database to identify randomized controlled trials evaluating the efficiency of tamsulosin in the treatment of ureteral stones. Meta-analysis and forest plots were carried out by use of Review Manager version 5.1 software (Cochrane Collaboration). Compared with the control group, the tamsulosin group had an increase in expulsion rate of 51% and a decrease in expulsion time of 2.63 days. Furthermore, tamsulosin was found to reduce the risk of ureteral colic during treatment by 40% and also the risk of requirement of auxiliary procedures during follow up by 60%. In terms of safety, the tamsulosin group had a 117% increase in the incidence of side-effects compared with the control group, especially for incidence of dizziness. Tamsulosin facilitates the expulsion of ureteral calculi by providing a higher expulsion rate, a shorter expulsion time, a lower incidence of ureteral colic during treatment and a lower requirement of auxiliary procedures. However, the incidence of dizziness occurring during tamsulosin treatment is significantly higher in this setting. © 2012 The Japanese Urological Association.

  20. Statistical Modeling of Occupational Exposure to Polycyclic Aromatic Hydrocarbons Using OSHA Data.

    Science.gov (United States)

    Lee, Derrick G; Lavoué, Jérôme; Spinelli, John J; Burstyn, Igor

    2015-01-01

    Polycyclic aromatic hydrocarbons (PAHs) are a group of pollutants with multiple variants classified as carcinogenic. The Occupational Safety and Health Administration (OSHA) provided access to two PAH exposure databanks of United States workplace compliance testing data collected between 1979 and 2010. Mixed-effects logistic models were used to predict the exceedance fraction (EF), i.e., the probability of exceeding OSHA's Permissible Exposure Limit (PEL = 0.2 mg/m3) for PAHs based on industry and occupation. Measurements of coal tar pitch volatiles were used as a surrogate for PAHs. Time, databank, occupation, and industry were included as fixed-effects while an identifier for the compliance inspection number was included as a random effect. Analyses involved 2,509 full-shift personal measurements. Results showed that the majority of industries had an estimated EF < 0.5, although several industries, including Standardized Industry Classification codes 1623 (Water, Sewer, Pipeline, and Communication and Powerline Construction), 1711 (Plumbing, Heating, and Air-Conditioning), 2824 (Manmade Organic Fibres), 3496 (Misc. Fabricated Wire products), and 5812 (Eating Places), and Major group's 13 (Oil and Gas Extraction) and 30 (Rubber and Miscellaneous Plastic Products), were estimated to have more than an 80% likelihood of exceeding the PEL. There was an inverse temporal trend of exceeding the PEL, with lower risk in most recent years, albeit not statistically significant. Similar results were shown when incorporating occupation, but varied depending on the occupation as the majority of industries predicted at the administrative level, e.g., managers, had an estimated EF < 0.5 while at the minimally skilled/laborer level there was a substantial increase in the estimated EF. These statistical models allow the prediction of PAH exposure risk through individual occupational histories and will be used to create a job-exposure matrix for use in a population-based case

  1. Petroleum hydrocarbons

    International Nuclear Information System (INIS)

    Farrington, J.W.; Teal, J.M.; Parker, P.L.

    1976-01-01

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

  2. Regional modelling of polycyclic aromatic hydrocarbons: WRF-Chem-PAH model development and East Asia case studies

    Science.gov (United States)

    Mu, Qing; Lammel, Gerhard; Gencarelli, Christian N.; Hedgecock, Ian M.; Chen, Ying; Přibylová, Petra; Teich, Monique; Zhang, Yuxuan; Zheng, Guangjie; van Pinxteren, Dominik; Zhang, Qiang; Herrmann, Hartmut; Shiraiwa, Manabu; Spichtinger, Peter; Su, Hang; Pöschl, Ulrich; Cheng, Yafang

    2017-10-01

    Polycyclic aromatic hydrocarbons (PAHs) are hazardous pollutants, with increasing emissions in pace with economic development in East Asia, but their distribution and fate in the atmosphere are not yet well understood. We extended the regional atmospheric chemistry model WRF-Chem (Weather Research Forecast model with Chemistry module) to comprehensively study the atmospheric distribution and the fate of low-concentration, slowly degrading semivolatile compounds. The WRF-Chem-PAH model reflects the state-of-the-art understanding of current PAHs studies with several new or updated features. It was applied for PAHs covering a wide range of volatility and hydrophobicity, i.e. phenanthrene, chrysene and benzo[a]pyrene, in East Asia. Temporally highly resolved PAH concentrations and particulate mass fractions were evaluated against observations. The WRF-Chem-PAH model is able to reasonably well simulate the concentration levels and particulate mass fractions of PAHs near the sources and at a remote outflow region of East Asia, in high spatial and temporal resolutions. Sensitivity study shows that the heterogeneous reaction with ozone and the homogeneous reaction with the nitrate radical significantly influence the fate and distributions of PAHs. The methods to implement new species and to correct the transport problems can be applied to other newly implemented species in WRF-Chem.

  3. Reduced combustion mechanism for C1-C4 hydrocarbons and its application in computational fluid dynamics flare modeling.

    Science.gov (United States)

    Damodara, Vijaya; Chen, Daniel H; Lou, Helen H; Rasel, Kader M A; Richmond, Peyton; Wang, Anan; Li, Xianchang

    2017-05-01

    Emissions from flares constitute unburned hydrocarbons, carbon monoxide (CO), soot, and other partially burned and altered hydrocarbons along with carbon dioxide (CO 2 ) and water. Soot or visible smoke is of particular concern for flare operators/regulatory agencies. The goal of the study is to develop a computational fluid dynamics (CFD) model capable of predicting flare combustion efficiency (CE) and soot emission. Since detailed combustion mechanisms are too complicated for (CFD) application, a 50-species reduced mechanism, LU 3.0.1, was developed. LU 3.0.1 is capable of handling C 4 hydrocarbons and soot precursor species (C 2 H 2 , C 2 H 4 , C 6 H 6 ). The new reduced mechanism LU 3.0.1 was first validated against experimental performance indicators: laminar flame speed, adiabatic flame temperature, and ignition delay. Further, CFD simulations using LU 3.0.1 were run to predict soot emission and CE of air-assisted flare tests conducted in 2010 in Tulsa, Oklahoma, using ANSYS Fluent software. Results of non-premixed probability density function (PDF) model and eddy dissipation concept (EDC) model are discussed. It is also noteworthy that when used in conjunction with the EDC turbulence-chemistry model, LU 3.0.1 can reasonably predict volatile organic compound (VOC) emissions as well. A reduced combustion mechanism containing 50 C 1 -C 4 species and soot precursors has been developed and validated against experimental data. The combustion mechanism is then employed in the computational fluid dynamics (CFD) of modeling of soot emission and combustion efficiency (CE) of controlled flares for which experimental soot and CE data are available. The validated CFD modeling tools are useful for oil, gas, and chemical industries to comply with U.S. Environmental Protection Agency's (EPA) mandate to achieve smokeless flaring with a high CE.

  4. Hydrocarbon potential of a new Jurassic play, central Tunisia

    International Nuclear Information System (INIS)

    Beall, A.O.; Law, C.W.

    1996-01-01

    A largely unrecognized Jurassic Sag Basin has been identified in central Tunisia, proximal to the Permo-Carboniferous flexure delineating the northern boundary of the Saharan platform of north Africa. The northwestern margin of the Sag is delineated by an extensive region of salt-cored anticlines and localized salt diapirs extending north and west. Due to lack of deep drilling, delineation of the Sag is largely based on regional gravity data. Subsidence of the Jurassic Sag Basin is characterized by rapid expansion of Jurassic sediments from 400 m. of tidal flat and shelf carbonate at the western outcrop to over 2000 meters of tidal flat and basinal carbonate and shale within the basin center, a five-fold expansion. Rapid loading of the basin continued into Lower Cretaceous time, marked by lateral flowage of Triassic salt into pronounced structural trends. Published source rock data and interpreted subsurface well data provided the basis for GENEX 1-D hydrocarbon generation and expulsion modeling of the Sag. Middle Jurassic black source shales typically contain Type II and Type III kerogens with T.O.C.'s ranging up to 4 percent. Modeling results indicate that middle Jurassic shales are presently mature for liquid generation within portions of the Sag, with maximum generation taking place during the Tertiary. Potential hydrocarbon generation yields, based on 60 meters of mature source shale, are 20,000 BOE/acre for gas and 75,000 BOE/acre for liquids. Prospects within the region could contain an estimated potential reserve of several T.C.F. or over 1 billion barrels of oil

  5. Receptor modeling of C2─C7 hydrocarbon sources at an urban background site in Zurich, Switzerland: changes between 1993─1994 and 2005─2006

    Directory of Open Access Journals (Sweden)

    S. Reimann

    2008-05-01

    Full Text Available Hourly measurements of 13 volatile hydrocarbons (C2–C7 were performed at an urban background site in Zurich (Switzerland in the years 1993–1994 and again in 2005–2006. For the separation of the volatile organic compounds by gas-chromatography (GC, an identical chromatographic column was used in both campaigns. Changes in hydrocarbon profiles and source strengths were recovered by positive matrix factorization (PMF. Eight and six factors could be related to hydrocarbon sources in 1993–1994 and in 2005–2006, respectively. The modeled source profiles were verified by hydrocarbon profiles reported in the literature. The source strengths were validated by independent measurements, such as inorganic trace gases (NOx, CO, SO2, methane (CH4, oxidized hydrocarbons (OVOCs and meteorological data (temperature, wind speed etc.. Our analysis suggests that the contribution of most hydrocarbon sources (i.e. road traffic, solvents use and wood burning decreased by a factor of about two to three between the early 1990s and 2005–2006. On the other hand, hydrocarbon losses from natural gas leakage remained at relatively constant levels (−20%. The estimated emission trends are in line with the results from different receptor-based approaches reported for other European cities. Their differences to national emission inventories are discussed.

  6. Symbiosis regulation in a facultatively symbiotic temperate coral: zooxanthellae division and expulsion

    Science.gov (United States)

    Dimond, J.; Carrington, E.

    2008-09-01

    Zooxanthellae mitotic index (MI) and expulsion rates were measured in the facultatively symbiotic scleractinian Astrangia poculata during winter and summer off the southern New England coast, USA. While MI was significantly higher in summer than in winter, mean expulsion rates were comparable between seasons. Corals therefore appear to allow increases in symbiont density when symbiosis is advantageous during the warm season, followed by a net reduction during the cold season when zooxanthellae may draw resources from the coral. Given previous reports that photosynthesis in A. poculata symbionts does not occur below approximately 6°C, considerable zooxanthellae division at 3°C and in darkness suggests that zooxanthellae are heterotrophic at low seasonal temperatures. Finally, examination of expulsion as a function of zooxanthellae density revealed that corals with very low zooxanthellae densities export a significantly greater proportion of their symbionts, apparently allowing them to persist in a stable azooxanthellate state.

  7. The expulsion of Jesuits from Nueva Granada in 185Oas key for understanding

    Directory of Open Access Journals (Sweden)

    José David Cortés Guerrero

    2003-01-01

    Full Text Available This article shows the confrontation between the liberal ideology of the mid nineteenth century and the conservative positions of the time as a result of the expulsion of the Society of Jesus from the Nueva Granada. The expulsion of the Jesuits encapsulates several key aspects of liberal ideology: the need to break with the colonial past; progress and civilization as attainable objectives; education as a neutral in terms of religious instruction; and the separation of the Catholic Church from the State as an important factor for reaching modernization and modernity. With the expulsion of the Jesuits one can also see the aligning of the nascent political parties, some defended the expulsión, others opposed it vehemently.

  8. Find-rate methodology and resource base estimates of the Hydrocarbon Supply Model (1990 update). Topical report

    International Nuclear Information System (INIS)

    Woods, T.

    1991-02-01

    The Hydrocarbon Supply Model is used to develop long-term trends in Lower-48 gas production and costs. The model utilizes historical find-rate patterns to predict the discovery rate and size distribution of future oil and gas field discoveries. The report documents the methodologies used to quantify historical oil and gas field find-rates and to project those discovery patterns for future drilling. It also explains the theoretical foundations for the find-rate approach. The new field and reserve growth resource base is documented and compared to other published estimates. The report has six sections. Section 1 provides background information and an overview of the model. Sections 2, 3, and 4 describe the theoretical foundations of the model, the databases, and specific techniques used. Section 5 presents the new field resource base by region and depth. Section 6 documents the reserve growth model components

  9. The use of solvent extractions and solubility theory to discern hydrocarbon associations in coal, with application to the coal-supercritical CO2 system

    Science.gov (United States)

    Kolak, Jonathan J.; Burruss, Robert A.

    2014-01-01

    findings indicate that hydrocarbon solubility does not exert a strong influence on hydrocarbon behavior in the systems studied. Other factors such as coal composition and maceral content, surface processes (physisorption), or other molecular interactions appear to affect the partitioning of hydrocarbons within the coal–supercritical CO2 system. Resolving the extent to which these factors might affect hydrocarbon behavior under different geological settings is important to efforts seeking to model petroleum generation, fractionation and expulsion from coal beds and to delineate potential hydrocarbon fate and transport in geologic CO2 sequestration settings.

  10. BASIN ANALYSIS AND PETROLEUM SYSTEM CHARACTERIZATION AND MODELING, INTERIOR SALT BASINS, CENTRAL AND EASTERN GULF OF MEXICO

    Energy Technology Data Exchange (ETDEWEB)

    Ernest A. Mancini; Donald A. Goddard; Ronald K. Zimmerman

    2005-05-10

    The principal research effort for Year 2 of the project has been data compilation and the determination of the burial and thermal maturation histories of the North Louisiana Salt Basin and basin modeling and petroleum system identification. In the first nine (9) months of Year 2, the research focus was on the determination of the burial and thermal maturation histories, and during the remainder of the year the emphasis has basin modeling and petroleum system identification. Existing information on the North Louisiana Salt Basin has been evaluated, an electronic database has been developed, regional cross sections have been prepared, structure and isopach maps have been constructed, and burial history, thermal maturation history and hydrocarbon expulsion profiles have been prepared. Seismic data, cross sections, subsurface maps and related profiles have been used in evaluating the tectonic, depositional, burial and thermal maturation histories of the basin. Oil and gas reservoirs have been found to be associated with salt-supported anticlinal and domal features (salt pillows, turtle structures and piercement domes); with normal faulting associated with the northern basin margin and listric down-to-the-basin faults (state-line fault complex) and faulted salt features; and with combination structural and stratigraphic features (Sabine and Monroe Uplifts) and monoclinal features with lithologic variations. Petroleum reservoirs are mainly Upper Jurassic and Lower Cretaceous fluvial-deltaic sandstone facies and Lower Cretaceous and Upper Cretaceous shoreline, marine bar and shallow shelf sandstone facies. Cretaceous unconformities significantly contribute to the hydrocarbon trapping mechanism capacity in the North Louisiana Salt Basin. The chief petroleum source rock in this basin is Upper Jurassic Smackover lime mudstone beds. The generation of hydrocarbons from Smackover lime mudstone was initiated during the Early Cretaceous and continued into the Tertiary

  11. Purifying hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Demoulins, H D; Garner, F H

    1923-02-07

    Hydrocarbon distillates, including natural gases and vapors produced by cracking hydrocarbon oils, are desulfurized etc. by treating the vapor with an aqueous alkaline solution of an oxidizing agent. The hydrocarbons may be previously purified by sulfuric acid. In examples aqueous solutions of sodium or calcium hydrochlorite containing 1.5 to 5.0 grams per liter of available chlorine and sufficient alkali to give an excess of 0.1 percent in the spent reagent are preheated to the temperature of the vapor, and either sprayed or atomized into the vapors near the outlet of the dephlegmator or fractionating tower, or passed in countercurrent to the vapors through one or a series of scrubbers.

  12. Reactivity of hydrocarbons in response to injection of a CO2/O2 mixture under depleted reservoir conditions: experimental and numerical modeling

    International Nuclear Information System (INIS)

    Pacini-Petitjean, Claire

    2015-01-01

    The geological storage of CO 2 (CO 2 Capture-Storage - CCS) and the Enhanced Oil Recovery (EOR) by CO 2 injection into petroleum reservoirs could limit CO 2 atmospheric accumulation. However, CO 2 can be associated with oxygen. To predict the hydrocarbon evolution under these conditions involves the study of oxidation mechanisms. Oxidation experiment and kinetic detailed modeling were carried out with pure compounds. The comparison between experimental and modeling results led to the construction of a hydrocarbon oxidation kinetic model and emphasized the parameters leading to auto ignition. The good agreement between our experiments and modeling are promising for the development of a tool predicting the critical temperature leading to auto-ignition and the evolution of hydrocarbon composition, to estimate the stability of a petroleum system in CO 2 injection context. (author) [fr

  13. Activity coefficients at infinite dilution of hydrocarbons in glycols: Experimental data and thermodynamic modeling with the GCA-EoS

    International Nuclear Information System (INIS)

    González Prieto, Mariana; Williams-Wynn, Mark D.; Bahadur, Indra; Sánchez, Francisco A.; Mohammadi, Amir H.

    2017-01-01

    Highlights: • Experimental infinite dilution activity coefficients of hydrocarbons in glycols. • Inverse gas-liquid chromatography technique. • Solutes investigated include n-alkanes, 1-alkenes, and cycloalkanes. • Highly non-ideal systems are modeled with the GCA-EoS. - Abstract: The infinite dilution activity coefficients for 12 non-polar hydrocarbon solutes in the solvents, monoethylene and diethylene glycol, were measured using the gas-liquid chromatography technique. Pre-saturation of the carrier gas was required to avoid solvent loss from the chromatographic column during the measurements that were carried out at T = (303.15, 313.15 and 323.15) K for monoethylene glycol and at T = (304.15, 313.15 and 323.15) K for diethylene glycol. The solutes investigated include n-alkanes, 1-alkenes, and cycloalkanes. The new data are compared with the highly scattered data that is available in the open literature. Finally, these highly non-ideal systems are modeled with the GCA-EoS.

  14. Revised models for hydrocarbon generation, migration and accumulation in Jurassic coal measures of the Turpan basin, NW China

    Energy Technology Data Exchange (ETDEWEB)

    Li Maowen; Stasiuk, L.D. [Geological Survey of Canada, Calgary, Alberta (Canada); Bao Jianping [Jianghan Petroleum University, Hubei (China); Lin, R. [Petroleum University (Beijing), Changping (China); Yuan Mingsheng [PetroChina Tu-Ha Oilfield Company, Xingjiang (China)

    2001-07-01

    Whether or not the Lower-Middle Jurassic coal measures in the Turpan basin of NW China have generated commercial quantities of liquid petroleums is a problem of considerable importance that remains contentious as it has not yet been resolved unequivocally. This study provides evidence against the Jurassic humic coals as the only major source for the oils discovered in the Taibei depression of this basin and suggests additional significant contributions from the Upper Permian and Middle-Lower Jurassic lacustrine source rocks. The Carboniferous-Permian marine source rocks may have been important also in limited locations along the major basement faults. Molecular and petrographic data indicate that the majority of the Middle Jurassic strata are currently immature or marginally mature with respect to hydrocarbon generation. Within the major depocenters, the Middle-Lower Jurassic coal-bearing strata of the Baodaowan and Xishanyao formations has reached the conventional oil window (i.e. with vitrinite reflectance >0.7 per cent Ro). Pre-Jurassic (Upper Permian in particular) derived hydrocarbons appear to be widespread in extracts of fractured Jurassic coal and fine-grained rocks. Large differences have been observed in the absolute concentrations of biomarker compounds in rock extracts of various source intervals. Thus, 'coaly' biomarker signatures of the oils most likely resulted from mixing and migration contamination when hydrocarbons derived from mature source rocks migrated up through highly fractured coal seams along deep-seated faults. In addition to conventional exploration targets, revised petroleum generation and accumulation models predict that the focus in the Turpan basin should also include deep structures within the Carboniferous-Permian strata and subtle, low magnitude anticlines and stratigraphic traps within thr Triassic-Jurassic sections. (author)

  15. The INCOTUR model : estimation of losses in the tourism sector in Alcudia due to a hydrocarbon spill

    International Nuclear Information System (INIS)

    Bergueiro, J.R.; Moreno, S.; Guijarro, S.; Santos, A.; Serr, F.

    2006-01-01

    This paper presented a computer model that calculates the economic losses incurred by a hydrocarbon spill on a coastal area. In particular, it focused on the Balearic Islands in the Bay of Alcudia where the economy depends mainly on tourism. A large number of oil tankers carrying crude oil and petroleum products pass through the Balearic Sea. Any pollution resulting from a fuel spill can have a significant economic impact on both the tourism sector and the Balearic society in general. This study focused on the simulation of 18 spills of Jet A1 fuel oil, unleaded gasoline and Bunker C fuel oil. Simulations of the study area were produced with OILMAP, MIKE21, GNOME and ADIOS models which estimated the trajectories of various spills and the amount of oil washed ashore. The change in physical and chemical properties of the spilled hydrocarbons was also determined. The simulation models considered the trajectory followed by spills according to the type and amount of spill, weather conditions prevailing during the spill and the period immediately following the spill. The INCOTUR model was then used to calculate the economic losses resulting from an oil spill by considering the number of tonnes of oil washed ashore; number of days needed to organize cleanup; the percentage of tourism that will be maintained despite the effects of the spill; number of hotel beds; percentage of hotel occupancy by month; cost of package holidays; petty cash expenses; and, cost of advertising campaign for the affected area. With this data, the model can determine the number of days needed to clean and restore the coastline; monthly rate of recovery in tourism levels; and, losses in tourism sector. According to the INCOTUR model, the total losses incurred by a spill of 40,000 tonnes of Bunker C fuel, was estimated at 472 million Euros. 9 refs., 2 tabs., 12 figs

  16. The INCOTUR model : estimation of losses in the tourism sector in Alcudia due to a hydrocarbon spill

    Energy Technology Data Exchange (ETDEWEB)

    Bergueiro, J.R.; Moreno, S.; Guijarro, S.; Santos, A.; Serr, F. [Iles Balears Univ., Palma de Mallorca, Balearic Islands (Spain). Dept. of Chemistry

    2006-07-01

    This paper presented a computer model that calculates the economic losses incurred by a hydrocarbon spill on a coastal area. In particular, it focused on the Balearic Islands in the Bay of Alcudia where the economy depends mainly on tourism. A large number of oil tankers carrying crude oil and petroleum products pass through the Balearic Sea. Any pollution resulting from a fuel spill can have a significant economic impact on both the tourism sector and the Balearic society in general. This study focused on the simulation of 18 spills of Jet A1 fuel oil, unleaded gasoline and Bunker C fuel oil. Simulations of the study area were produced with OILMAP, MIKE21, GNOME and ADIOS models which estimated the trajectories of various spills and the amount of oil washed ashore. The change in physical and chemical properties of the spilled hydrocarbons was also determined. The simulation models considered the trajectory followed by spills according to the type and amount of spill, weather conditions prevailing during the spill and the period immediately following the spill. The INCOTUR model was then used to calculate the economic losses resulting from an oil spill by considering the number of tonnes of oil washed ashore; number of days needed to organize cleanup; the percentage of tourism that will be maintained despite the effects of the spill; number of hotel beds; percentage of hotel occupancy by month; cost of package holidays; petty cash expenses; and, cost of advertising campaign for the affected area. With this data, the model can determine the number of days needed to clean and restore the coastline; monthly rate of recovery in tourism levels; and, losses in tourism sector. According to the INCOTUR model, the total losses incurred by a spill of 40,000 tonnes of Bunker C fuel, was estimated at 472 million Euros. 9 refs., 2 tabs., 12 figs.

  17. A Study of the Effectiveness of a Saturday School in Reducing Suspension, Expulsion, and Corporal Punishment.

    Science.gov (United States)

    Winborn, John Douglas

    Lack of proper discipline in schools has long been a major concern of the public. Proposals on how to improve discipline have ranged from the bizarre to the cruel. Educators and administrators must devise alternative punishments to replace traditional methods, such as corporal punishment, suspension, and expulsion, that are frequently ineffective.…

  18. Expulsion of the swine whipworm, Trichuris suis 

    DEFF Research Database (Denmark)

    Kringel, Helene

    demonstrating the potential use of its eggs as immunomodulators, treating patients suffering from inflammatory bowel disease and possibly other autoimmune diseases. The immune response induced by T. suis in its host and particularly, the resulting expulsion of worms is the focus of this thesis. Whipworms...

  19. Responses to the 1983 Expulsion of Aliens from Nigeria: A Critique ...

    African Journals Online (AJOL)

    This paper attempts a critique of this plethora of criticisms and submits that the Nigerian government of Shehu Shagari acted in conformity with the Nigerian immigration law of 1963 as informed by the exigencies of national interest. Government should therefore be exonerated from all the said criticisms. Keywords: Expulsion ...

  20. Medical expulsive therapy for ureteral stones: where do we go from here?

    NARCIS (Netherlands)

    Somani, Bhaskar K.; Aboumarzouk, Omar; Traxer, Olivier; Baard, Joyce; Kamphuis, Guido; de la Rosette, Jean

    2016-01-01

    Despite two decades of clinical use, the effectiveness of medical expulsive therapy (MET) for the noninvasive management of patients with ureteral stones has, in the past year, been called into in question. The primary aim of MET is to expedite stone passage, although it has also shown effectiveness

  1. Purifying hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Dunstan, A E

    1918-06-03

    Ligroin, kerosene, and other distillates from petroleum and shale oil, are purified by treatment with a solution of a hypochlorite containing an excess of alkali. The hydrocarbon may be poured into brine, the mixture stirred, and an electric current passed through. Heat may be applied.

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

    International Nuclear Information System (INIS)

    Rawson, S.A.; Walton, J.C.; Baca, R.G.

    1989-01-01

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

  3. Evaluation of gastrointestinal solubilization of petroleum hydrocarbon residues in soil using an in vitro physiologically based model.

    Science.gov (United States)

    Holman, Hoi-Ying N; Goth-Goldstein, Regine; Aston, David; Yun, Mao; Kengsoontra, Jenny

    2002-03-15

    Petroleum hydrocarbon residues in weathered soils may pose risks to humans through the ingestion pathway. To understand the factors controlling their gastrointestinal (GI) absorption, a newly developed experimental extraction protocol was used to model the GI solubility of total petroleum hydrocarbon (TPH) residues in highly weathered soils from different sites. The GI solubility of TPH residues was significantly higher for soil contaminated with diesel than with crude oil. Compared to the solubility of TPH residues during fasted state,the solubility of TPH residues during fat digestion was much greater. Diesel solubility increased from an average of 8% during the "gallbladder empty" phase of fasting (and less than 0.2% during the otherfasting phase) to an average of 16% during fat digestion. For crude oil, the solubility increased from an average of 1.2% during the gallbladder empty phase of fasting (and undetectable during the other fasting phase) to an average of 4.5% during fat digestion. Increasing the concentration of bile salts also increased GI solubility. GI solubility was reduced by soil organic carbon but enhanced by the TPH content.

  4. Efficacy and safety of tamsulosin as a medical expulsive therapy for stones in children.

    Science.gov (United States)

    Aldaqadossi, Hussein A; Shaker, Hossam; Saifelnasr, Mohammed; Gaber, Mohammed

    2015-06-01

    To evaluate the efficacy of tamsulosin for promoting ureteric stone expulsion in children, based on the confirmed efficacy of tamsulosin as a medical expulsive therapy in adults. From February 2010 to July 2013, 67 children presenting with a distal ureteric stone of <1 cm as assessed on unenhanced computed tomography were included in the study. The patients were randomised into two groups, with group 1 (33 patients) receiving tamsulosin 0.4 mg and ibuprofen, and group 2 (34) receiving ibuprofen only. They were followed up for 4 weeks. Endoscopic intervention was indicated for patients with uncontrolled pain, recurrent urinary tract infection, hypersensitivity to tamsulosin and failure of stone passage after 4 weeks of conservative treatment. Sixty-three patients completed the study. There were no statistically significant differences between the groups in patient age, body weight and stone size, the mean (SD) of which was 6.52 (1.8) mm in group 1 vs. 6.47 (1.79) mm in group 2 (P = 0.9). The mean (SD) time to stone expulsion in group 1 was 7.7 (1.9) days, vs. 18 (1.73) days in group 2 (P < 0.001). The analgesic requirement (mean number of ketorolac injections) in group 1 was significantly less than in group 2, at 0.55 (0.8) vs. 1.8 (1.6) (P < 0.001). The stone-free rate was 87% in group 1 and 63% in group 2 (P = 0.025). Tamsulosin used as a medical expulsive therapy for children with ureteric stones is safe and effective, as it facilitates spontaneous expulsion of the stone.

  5. Tamsulosin versus tadalafil as a medical expulsive therapy for distal ureteral stones: A prospective randomized study.

    Science.gov (United States)

    Kc, Hari Bahadur; Shrestha, Anil; Acharya, Ganesh Bhakta; Basnet, Robin Bahadur; Shah, Arvind Kumar; Shrestha, Parash Mani

    2016-09-01

    This study aimed to compare the safety and efficacy of tamsulosin and tadalafil as medical expulsive therapy for distal ureteral stones. This prospective randomized study was conducted at the Department of Urology of Bir Hospital over a period of 12 months in patients with distal ureteral stones sized 5 to 10 mm. Patients were randomly divided into 2 groups: group A received tamsulosin 0.4 mg and group B received tadalafil 10 mg at bedtime for 2 weeks. Stone expulsion rate, number of ureteric colic episodes and pain score, analgesic requirements, and adverse drug effects were noted in both groups. Statistical analyses were performed by using Student t-test and chi-square test. Altogether 85 patients, 41 in group A and 44 in group B, were enrolled in the study. The patients' average age was 31.72±12.63 years, and the male-to-female ratio was 1.5:1. Demographic profiles, stone size, and baseline investigations were comparable between the 2 groups. The stone expulsion rate was significantly higher in the tadalafil group than in the tamsulosin group (84.1% vs. 61.0%, p=0.017). Although the occurrence of side effects was higher with tadalafil, this difference was not significant (p=0.099). There were no serious adverse effects. Tadalafil has a significantly higher stone expulsion rate than tamsulosin when used as a medical expulsive therapy for distal ureteral stones sized 5-10 mm. Both drugs are safe, effective, and well tolerated with minor side effects.

  6. 2Dbasin modelling of the hydrocarbon systems in the forearc basin of Sumatra; 2D-Beckenmodellierung des Kohlenwasserstoff-Systems im Forearc-Bereich von Sumatra

    Energy Technology Data Exchange (ETDEWEB)

    Stratmann, V.; Berglar, K.; Lutz, R.; Schloemer, S. [Bundesanstalt fuer Geowissenschaften und Rohstoffe, Hannover (Germany); Djajadihardja, Y.S. [Agency for the Assessment and Application of Technology, Jakarta (Indonesia)

    2008-10-23

    In the forearc basin of Sumatra, individual industrial drillings indicated the existence of hydrocarbons. The authors of the contribution under consideration report on an investigation of the hydrocarbon system within this forearc basin by means of a two-dimensional modelling of this basin. The structural development of the basins in the forearc area proceeded differently. Therefore, geophysical data for the investigation of the geological structures as well as geological/geochemical data were raised. The preliminary results of the two-dimensional modelling of the Simeulue basin northwest from Sumatra are presented.

  7. Model studies in hydrocarbon oxidation. Progress report, April 1--November 31, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Parkin, G.

    1993-12-31

    The research performed during the period 1 April--31 November 1993 has centered on an investigation of the chemistry of molecular terminal oxo complexes. In the long term, it is hoped that this research will provide results that are relevant to systems concerned with hydrocarbon oxidation. The authors have also carried studies of transition metal complexes that contain terminal sulfido, selenido and tellurido ligands, since a knowledge of the chemistry of the heavier congeners of this group will help provide a more complete understanding of the chemistry of transition metal oxo complexes. Furthermore, the chemistry of the metal sulfido derivatives will be directly related to hydrodesulfurization, an extremely important industrial process, for which transition metal-sulfido derivatives, e.g. MoS{sub 2}, are active catalysts.

  8. The quasi-ballistic model of electron mobility in liquid hydrocarbons

    International Nuclear Information System (INIS)

    Mozumder, A.

    1996-01-01

    A phenomenological theory of low-mobility liquid hydrocarbons is developed which includes electron ballistic motion in the quasi-free state, in competition with diffusion and trapping. For most low-mobility liquids the theory predicts consistently the effective mobility and activation energy, in agreement with experiments, using quasi-free mobility and trap density respectively as ∼ 100 cm 2 v -1 s -1 and ∼ 10 19 cm -3 . Field dependence of mobility if theoretically of quadratic type for relatively small fields, agreeing approximately with experimental data for n-hexane. Electron scavenging with ''good'' scavengers occurs via the quasi-free state at nearly diffusion-controlled rate; however the effect of large mean free path is seen clearly. (author)

  9. Uranium metallogenic model related to CO2 and hydrocarbon in granite type uranium deposits

    International Nuclear Information System (INIS)

    Ou Guangxi; Chen Anfu; Cui Jianyong; Xu Yinhuan; Wang Chunhua; Xu Yan

    2001-01-01

    The report is concerned with the inseparable connections between the uranium migration, enrichment rule and the geochemical characteristics of CO 2 and hydrocarbon gas, as well as the relations between the deposit locations and the gas abnormal distribution in rocky body, which are based on the analysis of some data and phenomena in 11 typical deposits in 2 granite type uranium ore fields, including the observations of 250 rocky fluid inclusion sections and the analyzed data of which 2470 are in gas composition, 200 in uranium content, 50 in thermometry. All the conclusions are drawn from different angles for the first time and this new exploration and advancement fills up the blank of gas geochemistry study in uranium deposits or other metal deposits

  10. Burial history, thermal history and hydrocarbon generation modelling of the Jurassic source rocks in the basement of the Polish Carpathian Foredeep and Outer Carpathians (SE Poland)

    Science.gov (United States)

    Kosakowski, Paweł; Wróbel, Magdalena

    2012-08-01

    Burial history, thermal maturity, and timing of hydrocarbon generation were modelled for the Jurassic source rocks in the basement of the Carpathian Foredeep and marginal part of the Outer Carpathians. The area of investigation was bounded to the west by Kraków, to the east by Rzeszów. The modelling was carried out in profiles of wells: Będzienica 2, Dębica 10K, Góra Ropczycka 1K, Goleszów 5, Nawsie 1, Pławowice E1 and Pilzno 40. The organic matter, containing gas-prone Type III kerogen with an admixture of Type II kerogen, is immature or at most, early mature to 0.7 % in the vitrinite reflectance scale. The highest thermal maturity is recorded in the south-eastern part of the study area, where the Jurassic strata are buried deeper. The thermal modelling showed that the obtained organic matter maturity in the initial phase of the "oil window" is connected with the stage of the Carpathian overthrusting. The numerical modelling indicated that the onset of hydrocarbon generation from the Middle Jurassic source rocks was also connected with the Carpathian thrust belt. The peak of hydrocarbon generation took place in the orogenic stage of the overthrusting. The amount of generated hydrocarbons is generally small, which is a consequence of the low maturity and low transformation degree of kerogen. The generated hydrocarbons were not expelled from their source rock. An analysis of maturity distribution and transformation degree of the Jurassic organic matter shows that the best conditions for hydrocarbon generation occurred most probably in areas deeply buried under the Outer Carpathians. It is most probable that the "generation kitchen" should be searched for there.

  11. Comparison of silodosin to tamsulosin for medical expulsive treatment of ureteral stones: a systematic review and meta-analysis.

    Science.gov (United States)

    Özsoy, Mehmet; Liatsikos, Evangelos; Scheffbuch, Nicolas; Kallidonis, Panagiotis

    2016-11-01

    This study aimed at comparing the success rates of silodosin to the most commonly used for medical expulsive therapy (MET) tamsulosin for the management of ureteral stones. A systematic review using the search string: "silodosin AND (ston* OR calcu* OR expul*)" was conducted on Pubmed, SCOPUS, Web of Science, Cochrane Central Register. The Primary endpoint was the stone expulsion rate. Secondary endpoint was the time to stone expulsion. Two authors independently screened the studies depending on inclusion and exclusion criteria. Meta-analysis and forest-plot figures were calculated with the software Review Manager (RevMan 5.3.5). Variations were evaluated with the χ 2 statistical method and heterogeneity with I 2 index. After screening of 39 publications obtained by the initial search, three randomized controlled trials were eligible to be included in the meta-analysis. 407 patients were pooled. Favorable results were observed for silodosin in terms of stone expulsion rates with a risk ratio of 1.33 (95 % CI 1.17-1.50) (I 2  = 0 %). Similarly, faster stone expulsion times were observed with silodosin when compared with tamsulosin. Mean difference -2.49 (95 % CI -3.40 to 1.58) (I 2  = 89 %). This meta-analysis showed significantly higher stone expulsion rates and faster expulsion times in favor of silodosin when compared to tamsulosin.

  12. Distribution of MEG and methanol in well-defined hydrocarbon and water systems: Experimental measurement and modeling using the CPA EoS

    DEFF Research Database (Denmark)

    Riaz, Muhammad; Yussuf, Mustafe A.; Kontogeorgis, Georgios

    2013-01-01

    + water. These data are satisfactorily correlated (binaries) and predicted (ternaries) using Cubic Plus Association (CPA) equation of state (EoS). CPA is also applied to binary LLE of aromatic hydrocarbon + water and VLE of methane + methanol. Finally the distribution of water and inhibitors (methanol...... and MEG) in various phases is modeled using CPA. The hydrocarbon phase consists of mixture-1 (methane, ethane, n-butane) or mixture-2 (methane, ethane, propane, n-butane, n-heptane, toluene and n-decane). CPA can satisfactorily predict the water content in the gas phase of the multicomponent systems...

  13. Receptor modelling study of polycyclic aromatic hydrocarbons in Jeddah, Saudi Arabia.

    Science.gov (United States)

    Alghamdi, Mansour A; Alam, Mohammed S; Yin, Jianxin; Stark, Christopher; Jang, Eunhwa; Harrison, Roy M; Shamy, Magdy; Khoder, Mamdouh I; Shabbaj, Ibrahim I

    2015-02-15

    Measurements of 14 polycyclic aromatic hydrocarbons (PAH) have been made in Jeddah, Saudi Arabia, with a view to establishing the concentrations in this major city, and quantifying the contributions of major sources. Particulate and vapour forms have been sampled and analysed separately. The concentrations are compared to measurements from other sites in the Middle Eastern region and are towards the lower end of the range, being far lower than concentrations reported from Riyadh (Saudi Arabia), Assiut (Egypt) and Tehran (Iran) but broadly similar to those measured in Damascus (Syria) and higher than those measured in Kuwait. The partitioning between vapour and particle phases is similar to that in data from Egypt and China, but with many compounds showing a higher particle-associated percentage than in Birmingham (UK) possibly reflecting a higher concentration of airborne particulate matter in the former countries. Concentrations in Jeddah were significantly higher at a site close to the oil refinery and a site close to a major ring road than at a suburban site to the north of the city. Application of positive matrix factorisation to the pooled data elicited three factors accounting respectively for 17%, 33% and 50% of the measured sum of PAH and these are interpreted as arising from gasoline vehicles, industrial sources, particularly the oil refinery, and to diesel/fuel oil combustion. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Permian-Triassic maturation and multistage migration of hydrocarbons in the Assistência Formation (Irati Subgroup, Paraná Basin, Brazil: implications for the exploration model

    Directory of Open Access Journals (Sweden)

    António Mateus

    Full Text Available New lines of geological evidence strongly suggest that the main period of hydrocarbon maturation within Assistência Formation should be Permian-Triassic, stimulated by a high geothermal gradient that also sustained various manifestations of hydrothermal activity. Three main stages of fluid/hydrocarbon migration can also be inferred on the basis of multiscale observations: confined flow in late Permian to Triassic times, depending on the local build-up of fluid pressures; heterogeneous flow in Lower Cretaceous, triggered by a rejuvenated temperature gradient assisted by the early developed permeability conditions; and a late flow possibly driven by local pressure gradients, after complete cooling of dolerite dykes/sills. The early maturation and multistage migration of hydrocarbons have significant consequences in the design of exploration models to be applied in Paraná Basin.

  15. Large-scale modeling on the fate and transport of polycyclic aromatic hydrocarbons (PAHs) in multimedia over China

    Science.gov (United States)

    Huang, Y.; Liu, M.; Wada, Y.; He, X.; Sun, X.

    2017-12-01

    In recent decades, with rapid economic growth, industrial development and urbanization, expanding pollution of polycyclic aromatic hydrocarbons (PAHs) has become a diversified and complicated phenomenon in China. However, the availability of sufficient monitoring activities for PAHs in multi-compartment and the corresponding multi-interface migration processes are still limited, especially at a large geographic area. In this study, we couple the Multimedia Fate Model (MFM) to the Community Multi-Scale Air Quality (CMAQ) model in order to consider the fugacity and the transient contamination processes. This coupled dynamic contaminant model can evaluate the detailed local variations and mass fluxes of PAHs in different environmental media (e.g., air, surface film, soil, sediment, water and vegetation) across different spatial (a county to country) and temporal (days to years) scales. This model has been applied to a large geographical domain of China at a 36 km by 36 km grid resolution. The model considers response characteristics of typical environmental medium to complex underlying surface. Results suggest that direct emission is the main input pathway of PAHs entering the atmosphere, while advection is the main outward flow of pollutants from the environment. In addition, both soil and sediment act as the main sink of PAHs and have the longest retention time. Importantly, the highest PAHs loadings are found in urbanized and densely populated regions of China, such as Yangtze River Delta and Pearl River Delta. This model can provide a good scientific basis towards a better understanding of the large-scale dynamics of environmental pollutants for land conservation and sustainable development. In a next step, the dynamic contaminant model will be integrated with the continental-scale hydrological and water resources model (i.e., Community Water Model, CWatM) to quantify a more accurate representation and feedbacks between the hydrological cycle and water quality at

  16. Mathematical modeling of biotransformations of oil hydrocarbons in the marine environment of Karkinitskii Bay in the Black Sea

    International Nuclear Information System (INIS)

    Leonov, A.V.; Chicherina, O.V.; Fashchuk, D.Y.

    2008-01-01

    Mathematical modelling is routinely used to study the behaviour of oil hydrocarbons (OHCs) during spills. In this study, mathematical modelling was used to examine the conditions of marine environmental pollution by OHCs and its self-purification as a result of transport by water flows and biochemical decomposition. The waters of Karkinitskii Bay in the Black Sea was chosen as the study site the because the exploitation of gas deposits since the 1980s has resulted in higher OHC concentrations. The conditions of marine environmental pollution by OHCs and water self-purification were reproduced based on available data and estimates of long-term mean monthly values of temperature, transparency, total light intensity, atmospheric precipitation, photo-period, water regime, and data on concentrations of biogenic substances and OHCs in the Danube water. OHC biotransformations in the marine environment were simulated by reproducing the biochemical activity of microflora and effecting substrate consumption processes, metabolic product excretions and biomass decay. The model provided estimates of the rates of decomposition of OHCs and oxygen consumption. The model results were in good agreement with experimental data. The model estimated the time needed for OHC concentrations to reach the maximum admissible concentration after pollution of the marine environment. 41 refs., 2 tabs., 6 figs

  17. Mathematical modeling of biotransformations of oil hydrocarbons in the marine environment of Karkinitskii Bay in the Black Sea

    Energy Technology Data Exchange (ETDEWEB)

    Leonov, A.V.; Chicherina, O.V. [Russian Academy of Sciences, Moscow (Russian Federation). Inst. of Oceanology; Fashchuk, D.Y. [Russian Academy of Sciences, Moscow (Russian Federation). Inst. of Geography

    2008-07-01

    Mathematical modelling is routinely used to study the behaviour of oil hydrocarbons (OHCs) during spills. In this study, mathematical modelling was used to examine the conditions of marine environmental pollution by OHCs and its self-purification as a result of transport by water flows and biochemical decomposition. The waters of Karkinitskii Bay in the Black Sea was chosen as the study site the because the exploitation of gas deposits since the 1980s has resulted in higher OHC concentrations. The conditions of marine environmental pollution by OHCs and water self-purification were reproduced based on available data and estimates of long-term mean monthly values of temperature, transparency, total light intensity, atmospheric precipitation, photo-period, water regime, and data on concentrations of biogenic substances and OHCs in the Danube water. OHC biotransformations in the marine environment were simulated by reproducing the biochemical activity of microflora and effecting substrate consumption processes, metabolic product excretions and biomass decay. The model provided estimates of the rates of decomposition of OHCs and oxygen consumption. The model results were in good agreement with experimental data. The model estimated the time needed for OHC concentrations to reach the maximum admissible concentration after pollution of the marine environment. 41 refs., 2 tabs., 6 figs.

  18. Simulating the dynamics of polycyclic aromatic hydrocarbon (PAH) in contaminated soil through composting by COP-Compost model.

    Science.gov (United States)

    Zhang, Yuan; Guan, Yidong; Shi, Qi

    2015-02-01

    Organic pollutants (OPs) are potentially present in composts, and the assessment of their content and bioaccessibility in these composts is of paramount importance to minimize the risk of soil contamination and improve soil fertility. In this work, integration of the dynamics of organic carbon (OC) and OPs in an overall experimental framework is first proposed and adopted to validate the applicability of the COP-Compost model and to calibrate the model parameters on the basis of what has been achieved with the COP-Compost model. The COP-Compost model was evaluated via composting experiments containing 16 US Environmental Protection Agency (USEPA) polycyclic aromatic hydrocarbons (PAHs) and the sorption coefficient (Kd) values of two types of OP: fluorenthene (FLT) and pyrene (PHE). In our study, these compounds are used to characterize the sequential extraction and are quantified as soluble, sorbed, and non-extractable fractions. The model was calibrated, and coupling the OC and OP modules improved the simulation of the OP behavior and bioaccessibility during composting. The results show good agreement between the simulated and experimental results describing the evolution of different organic pollutants using the OP module, as well as the coupling module. However, no clear relationship is found between the Kd and the property of organic fractions. Further estimation of parameters is still necessary to modify the insufficiency of this present research.

  19. Model studies for evaluating the neurobehavioral effects of complex hydrocarbon solvents. II. Neurobehavioral effects of white spirit in rat and human

    NARCIS (Netherlands)

    Lammers, J.H.C.M.; Emmen, H.H.; Muijser, H.; Hoogendijk, E.M.G.; McKee, R.H.; Owen, D.E.; Kulig, B.M.

    2007-01-01

    To evaluate the neurobehavioral effects of hydrocarbon solvents and to establish a working model for extrapolating animal test data to humans, studies were conducted which involved inhalation exposure of rats and humans to white spirit (WS). The specific objectives of these studies were to evaluate

  20. Spin transfer driven resonant expulsion of a magnetic vortex core for efficient rf detector

    Directory of Open Access Journals (Sweden)

    S. Menshawy

    2017-05-01

    Full Text Available Spin transfer magnetization dynamics have led to considerable advances in Spintronics, including opportunities for new nanoscale radiofrequency devices. Among the new functionalities is the radiofrequency (rf detection using the spin diode rectification effect in spin torque nano-oscillators (STNOs. In this study, we focus on a new phenomenon, the resonant expulsion of a magnetic vortex in STNOs. This effect is observed when the excitation vortex radius, due to spin torques associated to rf currents, becomes larger than the actual radius of the STNO. This vortex expulsion is leading to a sharp variation of the voltage at the resonant frequency. Here we show that the detected frequency can be tuned by different parameters; furthermore, a simultaneous detection of different rf signals can be achieved by real time measurements with several STNOs having different diameters. This result constitutes a first proof-of-principle towards the development of a new kind of nanoscale rf threshold detector.

  1. A Reappraisal of the Expulsion of Illegal Immigrants from Nigeria in 1983

    Directory of Open Access Journals (Sweden)

    Daouda Gary-Tounkara

    2016-04-01

    Full Text Available In recent years, Nigeria has been quietly expelling more and more immigrants from Niger, Mali, Chad and Cameroon. These foreigners – migrant workers or small traders – face the reinforcement of migration control and the blind fight of the government against Boko Haram. Despite its political instability, Nigeria remains a major immigration destination in West Africa. In this article, I analyze the “undocumented” expulsion of aliens in 1983, officially three million people. I argue that the expulsion was due to the economic crisis but also to a nationalist revenge against Ghana and a political calculation of President Shagari. This implies the exclusion of foreigners from the national labour market and the weakening of the supposed electoral base of his opponents.

  2. Saskia Sassen, Expulsions. Brutalité et complexité dans l’économie globale

    OpenAIRE

    Henrio, Yannick

    2016-01-01

    Dans Expulsions, la sociologue et économiste Saskia Sassen, spécialiste de la mondialisation, auteure notamment de Global City, où elle faisait déjà le constat d’une polarisation des inégalités sociales et économiques dans les villes mondiales, poursuit sa réflexion et émet l’hypothèse que « sous les aspects nationaux des diverses crises globales se manifestent des tendances systémiques émergentes, formées par une dynamique fondamentale élémentaire » (p. 19). L’« expulsion » serait l’expressi...

  3. Posterior Uterine Rupture Causing Fetal Expulsion into the Abdominal Cavity: A Rare Case of Neonatal Survival

    Directory of Open Access Journals (Sweden)

    K. Navaratnam

    2011-01-01

    Full Text Available Introduction. Uterine rupture is a potentially catastrophic complication of vaginal birth after caesarean section. We describe the sixth case of posterior uterine rupture, with intact lower segment scar, and the first neonatal survival after expulsion into the abdominal cavity with posterior rupture. Case Presentation. A multiparous woman underwent prostaglandin induction of labour for postmaturity, after one previous caesarean section. Emergency caesarean section for bradycardia revealed a complete posterior uterine rupture, with fetal and placental expulsion. Upon delivery, the baby required inflation breaths only. The patient required a subtotal hysterectomy but returned home on day 5 postnatally with her healthy baby. Discussion. Vaginal birth after caesarean section constitutes a trial of labour, and the obstetrician must be reactive to labour events. Posterior uterine rupture is extremely rare and may occur without conventional signs. Good maternal and fetal outcome is possible with a prompt, coordinated team response.

  4. Late Complication after Superficial Femoral Artery (SFA) Aneurysm: Stent-graft Expulsion Outside the Skin

    Energy Technology Data Exchange (ETDEWEB)

    Pecoraro, Felice, E-mail: felicepecoraro@libero.it; Sabatino, Ermanno R.; Dinoto, Ettore; Rosa, Giuliana La; Corte, Giuseppe; Bajardi, Guido [University of Palermo, Vascular Surgery Unit (Italy)

    2015-10-15

    A 78-year-old man presented with a 7-cm aneurysm in the left superficial femoral artery, which was considered unfit and anatomically unsuitable for conventional open surgery for multiple comorbidities. The patient was treated with stent-graft [Viabhan stent-graft (WL Gore and Associates, Flagstaff, AZ)]. Two years from stent-graft implantation, the patient presented a purulent secretion and a spontaneous external expulsion through a fistulous channel. No claudication symptoms or hemorrhagic signs were present. The pus and device cultures were positive for Staphylococcus aureus sensitive to piperacillin/tazobactam. Patient management consisted of fistula drainage, systemic antibiotic therapy, and daily wound dressing. At 1-month follow-up, the wound was closed. To our knowledge, this is the first case of this type of stent-graft complication presenting with external expulsion.

  5. Polycyclic aromatic hydrocarbons - fate and long-range atmospheric transport studied using a global model, EMAC-SVOC

    Science.gov (United States)

    Octaviani, Mega; Tost, Holger; Lammel, Gerhard

    2017-04-01

    Polycyclic aromatic hydrocarbons (PAHs) are emitted by incomplete combustion from fossil fuel, vehicles, and biomass burning. They may persist in environmental compartments, pose a health hazard and may bio accumulate along food chains. The ECHAM/MESSy Atmospheric Chemistry (EMAC) model had been used to simulate global tropospheric, stratospheric chemistry and climate. In this study, we improve the model to include simulations of the transport and fate of semi-volatile organic compounds (SVOC). The EMAC-SVOC model takes into account essential environmental processes including gas-particle partitioning, dry and wet deposition, chemical and bio-degradation, and volatilization from sea surface, soils, vegetation, and snow. The model was evaluated against observational data in the Arctic, mid-latitudes, and tropics, and further applied to study total environmental lifetime and long-range transport potential (LRTP) of PAHs. We selected four compounds for study, spanning a wide range of volatility, i.e., phenanthrene, fluoranthene, pyrene, and benzo[a]pyrene. Several LRTP indicators were investigated, including the Arctic contamination potential, meridional spreading, and zonal and meridional fluxes to remote regions.

  6. Receptor modelling study of polycyclic aromatic hydrocarbons in Jeddah, Saudi Arabia

    Energy Technology Data Exchange (ETDEWEB)

    Alghamdi, Mansour A. [Department of Environmental Sciences, Faculty of Meteorology, Environment and Arid Land Agriculture, King Abdulaziz University, Jeddah (Saudi Arabia); Alam, Mohammed S., E-mail: m.s.alam@bham.ac.uk [Division of Environmental Health and Risk Management, School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Yin, Jianxin; Stark, Christopher; Jang, Eunhwa [Division of Environmental Health and Risk Management, School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Harrison, Roy M., E-mail: r.m.harrison@bham.ac.uk [Department of Environmental Sciences, Faculty of Meteorology, Environment and Arid Land Agriculture, King Abdulaziz University, Jeddah (Saudi Arabia); Division of Environmental Health and Risk Management, School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Shamy, Magdy; Khoder, Mamdouh I.; Shabbaj, Ibrahim I. [Department of Environmental Sciences, Faculty of Meteorology, Environment and Arid Land Agriculture, King Abdulaziz University, Jeddah (Saudi Arabia)

    2015-02-15

    Measurements of 14 polycyclic aromatic hydrocarbons (PAH) have been made in Jeddah, Saudi Arabia, with a view to establishing the concentrations in this major city, and quantifying the contributions of major sources. Particulate and vapour forms have been sampled and analysed separately. The concentrations are compared to measurements from other sites in the Middle Eastern region and are towards the lower end of the range, being far lower than concentrations reported from Riyadh (Saudi Arabia), Assiut (Egypt) and Tehran (Iran) but broadly similar to those measured in Damascus (Syria) and higher than those measured in Kuwait. The partitioning between vapour and particle phases is similar to that in data from Egypt and China, but with many compounds showing a higher particle-associated percentage than in Birmingham (UK) possibly reflecting a higher concentration of airborne particulate matter in the former countries. Concentrations in Jeddah were significantly higher at a site close to the oil refinery and a site close to a major ring road than at a suburban site to the north of the city. Application of positive matrix factorisation to the pooled data elicited three factors accounting respectively for 17%, 33% and 50% of the measured sum of PAH and these are interpreted as arising from gasoline vehicles, industrial sources, particularly the oil refinery, and to diesel/fuel oil combustion. - Highlights: • Measurements of 14 PAH compounds in vapour and particulate phases at three sites. • Comparison of concentrations across Jeddah and Middle Eastern regions. • Application of positive matrix factorisation to identify possible sources.

  7. Receptor modelling study of polycyclic aromatic hydrocarbons in Jeddah, Saudi Arabia

    International Nuclear Information System (INIS)

    Alghamdi, Mansour A.; Alam, Mohammed S.; Yin, Jianxin; Stark, Christopher; Jang, Eunhwa; Harrison, Roy M.; Shamy, Magdy; Khoder, Mamdouh I.; Shabbaj, Ibrahim I.

    2015-01-01

    Measurements of 14 polycyclic aromatic hydrocarbons (PAH) have been made in Jeddah, Saudi Arabia, with a view to establishing the concentrations in this major city, and quantifying the contributions of major sources. Particulate and vapour forms have been sampled and analysed separately. The concentrations are compared to measurements from other sites in the Middle Eastern region and are towards the lower end of the range, being far lower than concentrations reported from Riyadh (Saudi Arabia), Assiut (Egypt) and Tehran (Iran) but broadly similar to those measured in Damascus (Syria) and higher than those measured in Kuwait. The partitioning between vapour and particle phases is similar to that in data from Egypt and China, but with many compounds showing a higher particle-associated percentage than in Birmingham (UK) possibly reflecting a higher concentration of airborne particulate matter in the former countries. Concentrations in Jeddah were significantly higher at a site close to the oil refinery and a site close to a major ring road than at a suburban site to the north of the city. Application of positive matrix factorisation to the pooled data elicited three factors accounting respectively for 17%, 33% and 50% of the measured sum of PAH and these are interpreted as arising from gasoline vehicles, industrial sources, particularly the oil refinery, and to diesel/fuel oil combustion. - Highlights: • Measurements of 14 PAH compounds in vapour and particulate phases at three sites. • Comparison of concentrations across Jeddah and Middle Eastern regions. • Application of positive matrix factorisation to identify possible sources

  8. Cracking hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Forwood, G F; Lane, M; Taplay, J G

    1921-10-07

    In cracking and hydrogenating hydrocarbon oils by passing their vapors together with steam over heated carbon derived from shale, wood, peat or other vegetable or animal matter, the gases from the condenser are freed from sulfuretted hydrogen, and preferably also from carbon dioxide, and passed together with oil vapors and steam through the retort. Carbon dioxide may be removed by passage through slaked lime, and sulfuretted hydrogen by means of hydrated oxide of iron. Vapors from high-boiling oils and those from low-boiling oils are passed alternately through the retort, so that carbon deposited from the high-boiling oils is used up during treatment of low-boiling oils.

  9. Distilling hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Bataafsche, N V; de Brey, J H.C.

    1918-10-30

    Hydrocarbons containing a very volatile constituent and less volatile constituents, such as casing-head gases, still gases from the distillation of crude petroleum and bituminous shale are separated into their constituents by rectification under pressure; a pressure of 20 atmospheres and limiting temperatures of 150/sup 0/C and 40/sup 0/C are mentioned as suitable. The mixture may be subjected to a preliminary treatment consisting in heating to a temperature below the maximum rectification temperature at a pressure greater than that proposed to be used in the rectification.

  10. Partial spontaneous anal expulsion of the right colon lipoma: An exceptional diagnostic circumstance

    Directory of Open Access Journals (Sweden)

    Fahmi Hamila

    Full Text Available Introduction: Lipomas are most common benign tumors of the colon. They are asymptomatic and fortuitously discovered on a morphological examination. Rarely, they cause complications such as acute intussusception. In this article, we reported an exceptional discovery mode of right colon lipoma. Case presentation: A 54-year-old woman has consulted for acute abdominal pain relieved by the anus emission of a fat ball that she brought back with her. Abdominal computed tomography scan showed the remaining part of a lipoma developed in her right colon. Laparoscopic right colonic resection was performed. Discussion: Colic lipomas are usually asymptomatic and surgical indication in these cases is debated, but it is indicated whenever complications occur such as acute intestinal intussusception. In this case, discovery mode was not considered as a complication because lipoma evacuation could have been complete. Radiological explorations and colonoscopy could evaluate the lesional state. When surgery is decided, intersecting therapeutic strategy of a short colonic resection guided by a colonization during colonoscopy should be considered. Conclusion: The spontaneous expulsion of a colonic lipoma is very rare. Our observation showed that this expulsion may be partial. +The changes that the lipoma undergoes can evoke a malignant cause. a supplement to take care of this eventuality is necessary. Keywords: Colonic lipoma, Spontaneous expulsion, Colectomy

  11. Source apportionment of the carcinogenic potential of polycyclic aromatic hydrocarbons (PAH) associated to airborne PM10 by a PMF model.

    Science.gov (United States)

    Callén, M S; Iturmendi, A; López, J M; Mastral, A M

    2014-02-01

    In order to perform a study of the carcinogenic potential of polycyclic aromatic hydrocarbons (PAH), benzo(a)pyrene equivalent (BaP-eq) concentration was calculated and modelled by a receptor model based on positive matrix factorization (PMF). Nineteen PAH associated to airborne PM10 of Zaragoza, Spain, were quantified during the sampling period 2001-2009 and used as potential variables by the PMF model. Afterwards, multiple linear regression analysis was used to quantify the potential sources of BaP-eq. Five sources were obtained as the optimal solution and vehicular emission was identified as the main carcinogenic source (35 %) followed by heavy-duty vehicles (28 %), light-oil combustion (18 %), natural gas (10 %) and coal combustion (9 %). Two of the most prevailing directions contributing to this carcinogenic character were the NE and N directions associated with a highway, industrial parks and a paper factory. The lifetime lung cancer risk exceeded the unit risk of 8.7 x 10(-5) per ng/m(3) BaP in both winter and autumn seasons and the most contributing source was the vehicular emission factor becoming an important issue in control strategies.

  12. Tamsulosin versus tamsulosin plus tadalafil as medical expulsive therapy for lower ureteric stones: a randomized controlled trial.

    Science.gov (United States)

    Jayant, Kumar; Agrawal, Rajendra; Agrawal, Swati

    2014-10-01

    To compare the efficacy of tamsulosin versus tamsulosin plus tadalafil as medical expulsive therapy for lower ureteric stones. Between January 2013 and December 2013, 244 patients presenting with distal ureteric stones (size 5-10 mm) were randomized equally to tamsulosin (group A) or tamsulosin plus tadalafil (group B). Therapy was given for a maximum of 4 weeks. Stone expulsion rate, time to stone expulsion, analgesic use, number of hospital visits for pain, follow up, endoscopic treatment and adverse effects of drugs were recorded. Statistical analyses were carried out using Student's t-test and the χ(2) -test. There was a statistically significant higher expulsion rate in group B compared with group A (83.6% vs 65.5%; P-value = 0.031) and a shorter time to expulsion (14.9 ± 4.4 days vs 16.7 ± 4.8 days; P-value = 0.003). Statistically significant differences were noted in terms of the number of hospital visits and analgesic requirement in favor of group B. There was no serious adverse event. An improvement in erectile function was noted in patients of group B compared with those of group A. Medical expulsive therapy for distal ureteric stones using tamsulosin plus tadalafil is safe, effective and well tolerated. Furthermore, tadalafil provides the additional advantage of improving erectile dysfunction when this condition coexists with a lower ureteric stone. © 2014 The Japanese Urological Association.

  13. Limitations of microbial hydrocarbon degradation at the Amon mud volcano (Nile deep-sea fan

    Directory of Open Access Journals (Sweden)

    J. Felden

    2013-05-01

    Full Text Available The Amon mud volcano (MV, located at 1250 m water depth on the Nile deep-sea fan, is known for its active emission of methane and non-methane hydrocarbons into the hydrosphere. Previous investigations showed a low efficiency of hydrocarbon-degrading anaerobic microbial communities inhabiting the Amon MV center in the presence of sulfate and hydrocarbons in the seeping subsurface fluids. By comparing spatial and temporal patterns of in situ biogeochemical fluxes, temperature gradients, pore water composition, and microbial activities over 3 yr, we investigated why the activity of anaerobic hydrocarbon degraders can be low despite high energy supplies. We found that the central dome of the Amon MV, as well as a lateral mud flow at its base, showed signs of recent exposure of hot subsurface muds lacking active hydrocarbon degrading communities. In these highly disturbed areas, anaerobic degradation of methane was less than 2% of the methane flux. Rather high oxygen consumption rates compared to low sulfide production suggest a faster development of more rapidly growing aerobic hydrocarbon degraders in highly disturbed areas. In contrast, the more stabilized muds surrounding the central gas and fluid conduits hosted active anaerobic hydrocarbon-degrading microbial communities. The low microbial activity in the hydrocarbon-vented areas of Amon MV is thus a consequence of kinetic limitations by heat and mud expulsion, whereas most of the outer MV area is limited by hydrocarbon transport.

  14. Uterine restoration after repeated sloughing of fibroids or vaginal expulsion following uterine artery embolization

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hye Ri; Kim, Nack Keun; Lee, Mee Hwa [Pochon CHA University, Department of Obstetrics and Gynecology, Bundang CHA General Hospital, Sungnam-si, Kyonggi-do (Korea); Kim, Man Deuk; Kim, Hee Jin; Yoon, Sang-Wook [Pochon CHA University, Department of Diagnostic Radiology, Bundang CHA General Hospital, Sungnam-si, Kyonggi-do (Korea); Park, Won Kyu [Yeungnam University, Department of Diagnostic Radiology, Kyongson, Dyongbuk (Korea)

    2005-09-01

    The aim of our study is to present our experience with uterine restoration after repeated sloughing of uterine fibroids or transvaginal expulsion following uterine artery embolization (UAE) and to determine its safety and outcome. One hundred and twenty-four women (mean age, 40.3 years; age range, 29-52 years) with symptomatic uterine fibroids were included in this retrospective study. We performed arterial embolization with poly(vinyl alcohol) particles (250-710 {mu}m). Clinical symptoms and follow-up information for each patient were obtained through medical records. At an average of 3.5 months (range, 1-8 months) after embolization, magnetic resonance imaging examinations with T1- and T2-weighted and gadolinium-enhanced T1-weighted images were obtained for all patients. The mean follow-up duration was 120 days (90-240 days). Eight (6.5%) patients experienced uterine restoration after repeated sloughing of uterine fibroids or spontaneous transvaginal expulsion. The locations of the leiomyomas were submucosal (n=5), intramural (n=2) and transmural (n=1). The maximum diameter of the fibroids ranged from 3.5 to 18.0 cm, with a mean of 8.4 cm. The time interval from embolization to the uterine restoration was 7-150 days (mean 70.5 days). The clinical symptoms before and during vaginal sloughing or expulsion were lower abdominal pain (n=4), vaginal discharges (n=3), infection of necrotic myomas (n=2) and cramping abdominal pain (n=1). Gentle abdominal compression (n=1) and hysteroscopic assistance (n=1) were required to remove the whole fibroid. No other clinical sequelae, either early or delayed, were documented. Magnetic resonance images revealed the disappearance of leiomyomas, intracavitary rupture resulting in transformation of intramural or transmural myomas into submucosal myomas and localized uterine wall defects. Although the small size of this study precludes a strict conclusion, there appear to be few serious complications directly related to vaginal

  15. Uterine restoration after repeated sloughing of fibroids or vaginal expulsion following uterine artery embolization

    International Nuclear Information System (INIS)

    Park, Hye Ri; Kim, Nack Keun; Lee, Mee Hwa; Kim, Man Deuk; Kim, Hee Jin; Yoon, Sang-Wook; Park, Won Kyu

    2005-01-01

    The aim of our study is to present our experience with uterine restoration after repeated sloughing of uterine fibroids or transvaginal expulsion following uterine artery embolization (UAE) and to determine its safety and outcome. One hundred and twenty-four women (mean age, 40.3 years; age range, 29-52 years) with symptomatic uterine fibroids were included in this retrospective study. We performed arterial embolization with poly(vinyl alcohol) particles (250-710 μm). Clinical symptoms and follow-up information for each patient were obtained through medical records. At an average of 3.5 months (range, 1-8 months) after embolization, magnetic resonance imaging examinations with T1- and T2-weighted and gadolinium-enhanced T1-weighted images were obtained for all patients. The mean follow-up duration was 120 days (90-240 days). Eight (6.5%) patients experienced uterine restoration after repeated sloughing of uterine fibroids or spontaneous transvaginal expulsion. The locations of the leiomyomas were submucosal (n=5), intramural (n=2) and transmural (n=1). The maximum diameter of the fibroids ranged from 3.5 to 18.0 cm, with a mean of 8.4 cm. The time interval from embolization to the uterine restoration was 7-150 days (mean 70.5 days). The clinical symptoms before and during vaginal sloughing or expulsion were lower abdominal pain (n=4), vaginal discharges (n=3), infection of necrotic myomas (n=2) and cramping abdominal pain (n=1). Gentle abdominal compression (n=1) and hysteroscopic assistance (n=1) were required to remove the whole fibroid. No other clinical sequelae, either early or delayed, were documented. Magnetic resonance images revealed the disappearance of leiomyomas, intracavitary rupture resulting in transformation of intramural or transmural myomas into submucosal myomas and localized uterine wall defects. Although the small size of this study precludes a strict conclusion, there appear to be few serious complications directly related to vaginal

  16. Dispersion modeling of polycyclic aromatic hydrocarbons from combustion of biomass and fossil fuels and production of coke in Tianjin, China.

    Science.gov (United States)

    Tao, Shu; Li, Xinrong; Yang, Yu; Coveney, Raymond M; Lu, Xiaoxia; Chen, Haitao; Shen, Weiran

    2006-08-01

    A USEPA, procedure, ISCLT3 (Industrial Source Complex Long-Term), was applied to model the spatial distribution of polycyclic aromatic hydrocarbons (PAHs) emitted from various sources including coal, petroleum, natural gas, and biomass into the atmosphere of Tianjin, China. Benzo[a]pyrene equivalent concentrations (BaPeq) were calculated for risk assessment. Model results were provisionally validated for concentrations and profiles based on the observed data at two monitoring stations. The dominant emission sources in the area were domestic coal combustion, coke production, and biomass burning. Mainly because of the difference in the emission heights, the contributions of various sources to the average concentrations at receptors differ from proportions emitted. The shares of domestic coal increased from approximately 43% at the sources to 56% at the receptors, while the contributions of coking industry decreased from approximately 23% at the sources to 7% at the receptors. The spatial distributions of gaseous and particulate PAHs were similar, with higher concentrations occurring within urban districts because of domestic coal combustion. With relatively smaller contributions, the other minor sources had limited influences on the overall spatial distribution. The calculated average BaPeq value in air was 2.54 +/- 2.87 ng/m3 on an annual basis. Although only 2.3% of the area in Tianjin exceeded the national standard of 10 ng/m3, 41% of the entire population lives within this area.

  17. Model-based evaluation of the use of polycyclic aromatic hydrocarbons molecular diagnostic ratios as a source identification tool

    International Nuclear Information System (INIS)

    Katsoyiannis, Athanasios; Breivik, Knut

    2014-01-01

    Polycyclic Aromatic Hydrocarbons (PAHs) molecular diagnostic ratios (MDRs) are unitless concentration ratios of pair-PAHs with the same molecular weight (MW); MDRs have long been used as a tool for PAHs source identification purposes. In the present paper, the efficiency of the MDR methodology is evaluated through the use of a multimedia fate model, the calculation of characteristic travel distances (CTD) and the estimation of air concentrations for individual PAHs as a function of distance from an initial point source. The results show that PAHs with the same MW are sometimes characterized by substantially different CTDs and therefore their air concentrations and hence MDRs are predicted to change as the distance from the original source increases. From the assessed pair-PAHs, the biggest CTD difference is seen for Fluoranthene (107 km) vs. Pyrene (26 km). This study provides a strong indication that MDRs are of limited use as a source identification tool. -- Highlights: • Model-based evaluation of the PAHs molecular diagnostic ratios efficiency. • Individual PAHs are characterized by different characteristic travel distances. • MDRs are proven to be a limited tool for source identification. • Use of MDRs for other environmental media is likely unfeasible. -- PAHs molecular diagnostic ratios which change greatly as a function of distance from the emitting source are improper for source identification purposes

  18. Tectonic controls on preservation of Middle Triassic Halfway reservoir facies, Peejay Field, northeastern British Columbia: a new hydrocarbon exploration model

    Energy Technology Data Exchange (ETDEWEB)

    Caplan, M. L. [British Columbia Univ., Vancouver, BC (Canada). Dept. of Geological Sciences; Moslow, T. F. [Calgary Univ., AB (Canada). Dept. of Geology and Geophysics

    1997-12-01

    The Peejay Field in northeastern British Columbia was chosen as the site of a detailed study to establish the paleogeography, geological history and genesis of reservoir facies of Middle Triassic strata. A total of 132 cores and well logs from 345 wells were examined to establish the depositional model, to identify the origin of all reservoir facies and to construct an exploration model to improve the prediction of reservoir facies. Results show that the Middle Triassic Halfway Formation of northeastern British Columbia is comprised of at least four west-southwest prograding paleoshorelines. The Lithofacies Succession One quartz-arenites paleoshore faces have less porosity and permeability and are laterally discontinuous. For these reasons shoreface facies have minimal reservoir quality. The tidal inlet fill successions were found to have the greatest observed porosity, permeability and lateral continuity in the Peejay Field. The geometry and orientation of these tidal inlet fill deposits are controlled by tectonic processes. It was suggested that the success of hydrocarbon exploration in this structurally complex area of northeastern British Columbia and west-central Alberta depends on further stratigraphic and sedimentological examination of Middle Triassic strata on a regional scale to obtain a complete understanding of the geological history of the area. 39 refs., 13 refs.

  19. Fate of polycyclic aromatic hydrocarbons from the North Pacific to the Arctic: Field measurements and fugacity model simulation.

    Science.gov (United States)

    Ke, Hongwei; Chen, Mian; Liu, Mengyang; Chen, Meng; Duan, Mengshan; Huang, Peng; Hong, Jiajun; Lin, Yan; Cheng, Shayen; Wang, Xuran; Huang, Mengxue; Cai, Minggang

    2017-10-01

    Polycyclic aromatic hydrocarbons (PAHs) have accumulated ubiquitously inArctic environments, where re-volatilization of certain organic pollutants as a result of climate change has been observed. To investigate the fate of semivolatile organic compounds in the Arctic, dissolved PAHs in the surface seawaters from the temperate Pacific Ocean to the Arctic Ocean, as well as a water column in the Arctic Ocean, were collected during the 4th Chinese National Arctic Research Expedition in summer 2010. The total concentrations of seven dissolved PAHs in surface water ranged from 1.0 to 5.1 ng L -1 , decreasing with increasing latitude. The vertical profile of PAHs in the Arctic Ocean was generally characteristic of surface enrichment and depth depletion, which emphasized the role of vertical water stratification and particle settling processes. A level III fugacity model was developed in the Bering Sea under steady state assumption. Model results quantitatively simulated the transfer processes and fate of PAHs in the air and water compartments, and highlighted a summer air-to-sea flux of PAHs in the Bering Sea, which meant that the ocean served as a sink for PAHs, at least in summer. Acenaphthylene and acenaphthene reached equilibrium in air-water diffusive exchange, and any perturbation, such as a rise in temperature, might lead to disequilibrium and remobilize these compounds from their Arctic reservoirs. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Source characterization and exposure modeling of gas-phase polycyclic aromatic hydrocarbon (PAH) concentrations in Southern California

    Science.gov (United States)

    Masri, Shahir; Li, Lianfa; Dang, Andy; Chung, Judith H.; Chen, Jiu-Chiuan; Fan, Zhi-Hua (Tina); Wu, Jun

    2018-03-01

    Airborne exposures to polycyclic aromatic hydrocarbons (PAHs) are associated with adverse health outcomes. Because personal air measurements of PAHs are labor intensive and costly, spatial PAH exposure models are useful for epidemiological studies. However, few studies provide adequate spatial coverage to reflect intra-urban variability of ambient PAHs. In this study, we collected 39-40 weekly gas-phase PAH samples in southern California twice in summer and twice in winter, 2009, in order to characterize PAH source contributions and develop spatial models that can estimate gas-phase PAH concentrations at a high resolution. A spatial mixed regression model was constructed, including such variables as roadway, traffic, land-use, vegetation index, commercial cooking facilities, meteorology, and population density. Cross validation of the model resulted in an R2 of 0.66 for summer and 0.77 for winter. Results showed higher total PAH concentrations in winter. Pyrogenic sources, such as fossil fuels and diesel exhaust, were the most dominant contributors to total PAHs. PAH sources varied by season, with a higher fossil fuel and wood burning contribution in winter. Spatial autocorrelation accounted for a substantial amount of the variance in total PAH concentrations for both winter (56%) and summer (19%). In summer, other key variables explaining the variance included meteorological factors (9%), population density (15%), and roadway length (21%). In winter, the variance was also explained by traffic density (16%). In this study, source characterization confirmed the dominance of traffic and other fossil fuel sources to total measured gas-phase PAH concentrations while a spatial exposure model identified key predictors of PAH concentrations. Gas-phase PAH source characterization and exposure estimation is of high utility to epidemiologist and policy makers interested in understanding the health impacts of gas-phase PAHs and strategies to reduce emissions.

  1. Fluid Expulsion, Habitability, and the Search for Life on Mars

    Science.gov (United States)

    Oehler, Dorothy Z.; Allen, Carlton C.

    2012-01-01

    Habitability assessments are critical for identifying settings in which potential biosignatures could exist in quantities large enough to be detected by rovers. Habitability depends on 1) the potential for long-lived liquid water, 2) conditions affording protection from surface processes destructive to organic biomolecules, and 3) a source of renewing nutrients and energy. Of these criteria, the latter is often overlooked. Here we present an analysis of a large "ghost" crater in northern Chryse Planitia [1] that appears to have satisfied each of these requirements, with several processes providing potential sources of nutrient/energy renewal [1-2]. This analysis can serve as a model for identifying other localities that could provide similarly favorable settings in which to seek evidence of life on Mars.

  2. Hydrocarbon oils

    Energy Technology Data Exchange (ETDEWEB)

    Foorwood, G F; Taplay, J G

    1916-12-12

    Hydrocarbon oils are hydrogenated, cracked, or treated for the removal of sulfur by bringing their vapors mixed with steam at temperatures between 450 and 600/sup 0/C into contact with a form of carbon that is capable of decomposing steam with the production of nascent hydrogen at those temperatures. The forms of carbon used include lamp-black, soot, charcoals derived from wood, cellulose, and lignite, and carbons obtained by carbonizing oil residues and other organic bodies at temperatures below 600/sup 0/C. The process is applied to the treatment of coal oil, shale oil, petroleum, and lignite oil. In examples, kerosene is cracked at 570/sup 0/C, cracked spirit is hydrogenated at 500/sup 0/C, and shale spirit is desulfurized at 530/sup 0/C. The products are led to a condenser and thence to a scrubber, where they are washed with creosote oil. After desulfurization, the products are washed with dilute caustic soda to remove sulfurretted hydrogen.

  3. Hydrocarbon exploration

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-01-01

    This special issue of the journal examines various aspects of the on-going search for hydrocarbons, ranging from frontier basins where little data are available, to more mature areas where considerable data are available. The incentives underlying the search for oil are roughly: the social, economic and industrial needs of a nation; the incentive of a corporation to be profitable; and the personal incentives of individuals in the oil industry and governments, which range from financial wealth to power and which are as diverse as the individuals who are involved. From a geopolitical perspective, the needs, requirements, goals, strategies, and philosophies of nations, and groups of nations, also impact on the oil exploration game. Strategies that have been employed have ranged from boycott to austerity and rationing, to physical intervention, to global ''flooding'' with oil by over-production. (author)

  4. THE HYDROCARBON SPILL SCREENING MODEL (HSSM), VOLUME 2: THEORETICAL BACKGROUND AND SOURCE CODES

    Science.gov (United States)

    A screening model for subsurface release of a nonaqueous phase liquid which is less dense than water (LNAPL) is presented. The model conceptualizes the release as consisting of 1) vertical transport from near the surface to the capillary fringe, 2) radial spreading of an LNAPL l...

  5. A new HYSYS model for underground gasification of hydrocarbons under hydrothermal conditions

    KAUST Repository

    Alshammari, Y.M.; Hellgardt, K.

    2014-01-01

    A new subsurface process model was developed using the ASPEN HYSYS simulation environment to analyse the process energy and gasification efficiency at steady-state equilibrium conditions. Injection and production wells were simulated using the HYSYS

  6. The use of sensory perception indicators for improving the characterization and modelling of total petroleum hydrocarbon (TPH) grade in soils.

    Science.gov (United States)

    Roxo, Sónia; de Almeida, José António; Matias, Filipa Vieira; Mata-Lima, Herlander; Barbosa, Sofia

    2016-03-01

    This paper proposes a multistep approach for creating a 3D stochastic model of total petroleum hydrocarbon (TPH) grade in potentially polluted soils of a deactivated oil storage site by using chemical analysis results as primary or hard data and classes of sensory perception variables as secondary or soft data. First, the statistical relationship between the sensory perception variables (e.g. colour, odour and oil-water reaction) and TPH grade is analysed, after which the sensory perception variable exhibiting the highest correlation is selected (oil-water reaction in this case study). The probabilities of cells belonging to classes of oil-water reaction are then estimated for the entire soil volume using indicator kriging. Next, local histograms of TPH grade for each grid cell are computed, combining the probabilities of belonging to a specific sensory perception indicator class and conditional to the simulated values of TPH grade. Finally, simulated images of TPH grade are generated by using the P-field simulation algorithm, utilising the local histograms of TPH grade for each grid cell. The set of simulated TPH values allows several calculations to be performed, such as average values, local uncertainties and the probability of the TPH grade of the soil exceeding a specific threshold value.

  7. Application of radiocarbon analysis and receptor modeling to the source apportionment of PAHs (polycyclic aromatic hydrocarbons) in the atmosphere

    International Nuclear Information System (INIS)

    Sheffield, A.E.

    1988-01-01

    The radiocarbon tracer technique was used to demonstrate that polycyclic aromatic hydrocarbons (PAHs) can be used for quantitative receptor modeling of air pollution. Fine-particle samples were collected during December, 1985, in Albuquerque, NM. Motor vehicles (fossil) and residential wood combustion (RWC, modern) were the major PAH-sources. For each sample, the PAH-fraction was solvent-extracted, isolated by liquid chromatography, and analyzed by GC-FID and GC-MS. The PAH-fractions from sixteen samples were analyzed for 14 C by Accelerator Mass Spectrometry. Radiocarbon data were used to calculate the relative RWC contribution (f RWC ) for samples analyzed for 14 C. Normalized concentrations of a prospective motor vehicle tracer, benzo(ghi)perylene (BGP) had a strong, negative correlation with f RWC . Normalized BGP concentrations were used to apportion sources for samples not analyzed for 14 C. Multiple Linear Regression (MLR) vs. ADCS and BGP was used to estimate source profiles for use in Target Factor Analysis (TFA). Profiles predicted by TFA were used in Chemical Mass Balances (CMBs). For non-volatile, stable PAHs, agreement between observed and predicted concentrations was excellent. The worst fits were observed for the most volatile PAHs and for coronene. The total RWC contributions predicted by CMBs correlated well with the radiocarbon data

  8. Modeling solubility of CO2/hydrocarbon gas in ionic liquid ([emim][FAP]) using Aspen Plus simulations.

    Science.gov (United States)

    Bagchi, Bishwadeep; Sati, Sushmita; Shilapuram, Vidyasagar

    2017-08-01

    The Peng-Robinson equation of state with quadratic van der Waals (vdW) mixing rule model was chosen to perform the thermodynamic calculations in Flash3 column of Aspen Plus to predict the solubility of CO 2 or any one of the hydrocarbons (HCs) among methane, ethane, propane, and butane in an ionic liquid 1-ethyl-3-methylimidazolium tris(pentafluoroethyl)trifluorophosphate ([emim][FAP]). Bubble point pressure, solubility, bubble point temperature, fugacity, and partial molar volume at infinite dilution were obtained from the simulations, and enthalpy of absorption, Gibbs free energy of solvation, and entropy change of absorption were estimated by thermodynamic relations. Results show that carbon chain length has a significant effect on the bubble point pressure. Methane has the highest bubble point pressure among all the considered HCs and CO 2 . The bubble point pressure and fugacity variation with temperature is different for CO 2 as compared to HCs for mole fractions above 0.2. Two different profiles are noticed for enthalpy of absorption when plotted as a function of mole fraction of gas soluble in IL. Partial molar volume of CO 2 decreases with increase in temperature in [emim][FAP], while it is increased for HCs. Bubble point temperature decreases with increase in the mole fraction of the solute. Entropy of solvation increases with temperature till a particular value followed by a decrease with further increase in temperature. Gibbs free energy change of solvation showed that the process of solubility was spontaneous.

  9. Watershed-scale modeling on the fate and transport of polycyclic aromatic hydrocarbons (PAHs)

    International Nuclear Information System (INIS)

    Ligaray, Mayzonee; Baek, Sang Soo; Kwon, Hye-Ok; Choi, Sung-Deuk; Cho, Kyung Hwa

    2016-01-01

    PAHs are potentially carcinogenic substances that are persistent in the environment. Increasing concentrations of PAHs were observed due to rapid urbanization, thus; monitoring PAHs concentrations is necessary. However, it is expensive to conduct intensive monitoring activities of a large number of PAHs. This study addressed this issue by developing a multimedia model coupled with a hydrological model (i.e., Soil and Water Assessment Tool (SWAT)) for Taehwa River (TR) watershed in Ulsan, the industrial capital of South Korea. The hydrologic module of the SWAT was calibrated, and further used to simulate the fate and transport of PAHs in soil and waterbody. The model demonstrated that the temporal or seasonal variation of PAHs in soil and waterbody can be well reproduced. Meanwhile, the spatial distribution of PAHs showed that urban areas in TR watershed have the highest PAH loadings compared to rural areas. Sensitivity analyses of the PAH soil and PAH water parameters were also able to determine the critical processes in TR watershed: degradation, deposition, volatilization, and wash off mechanism. We hope that this model will be able to aid the stakeholders in: regulating PAH concentrations emitted by various sources; and also apply the model to other Persistent Organic Pollutants (POPs).

  10. Watershed-scale modeling on the fate and transport of polycyclic aromatic hydrocarbons (PAHs)

    Energy Technology Data Exchange (ETDEWEB)

    Ligaray, Mayzonee; Baek, Sang Soo [School of Urban and Environmental Engineering, Ulsan National Institute of Science and Technology, UNIST-gil 50, Ulsan 44919 (Korea, Republic of); Kwon, Hye-Ok [Disaster Scientific Investigation Division, National Disaster Management Research Institute, 365 Jongga-ro Jung-gu, Ulsan 44538 (Korea, Republic of); Choi, Sung-Deuk, E-mail: sdchoi@unist.ac.kr [School of Urban and Environmental Engineering, Ulsan National Institute of Science and Technology, UNIST-gil 50, Ulsan 44919 (Korea, Republic of); Cho, Kyung Hwa, E-mail: khcho@unist.ac.kr [School of Urban and Environmental Engineering, Ulsan National Institute of Science and Technology, UNIST-gil 50, Ulsan 44919 (Korea, Republic of)

    2016-12-15

    PAHs are potentially carcinogenic substances that are persistent in the environment. Increasing concentrations of PAHs were observed due to rapid urbanization, thus; monitoring PAHs concentrations is necessary. However, it is expensive to conduct intensive monitoring activities of a large number of PAHs. This study addressed this issue by developing a multimedia model coupled with a hydrological model (i.e., Soil and Water Assessment Tool (SWAT)) for Taehwa River (TR) watershed in Ulsan, the industrial capital of South Korea. The hydrologic module of the SWAT was calibrated, and further used to simulate the fate and transport of PAHs in soil and waterbody. The model demonstrated that the temporal or seasonal variation of PAHs in soil and waterbody can be well reproduced. Meanwhile, the spatial distribution of PAHs showed that urban areas in TR watershed have the highest PAH loadings compared to rural areas. Sensitivity analyses of the PAH soil and PAH water parameters were also able to determine the critical processes in TR watershed: degradation, deposition, volatilization, and wash off mechanism. We hope that this model will be able to aid the stakeholders in: regulating PAH concentrations emitted by various sources; and also apply the model to other Persistent Organic Pollutants (POPs).

  11. Reservoir petrophysics and hydrocarbon occurrences of the Bahariya Formation, Alamein-Yidma fields, Western Desert of Egypt

    Energy Technology Data Exchange (ETDEWEB)

    Abdel-Aziz Younes, Mohamed [Alexandria Univ. (Egypt). Geology Dept.

    2012-12-15

    < 0.47. The burial history modeling revealed that the potential source rock in the Alamein basin is the marine shale source rock of the Middle Jurassic (Khatatba Formation). The Khatatba shale has mixed kerogen types II-III and entered the mid- mature stage of oil generation window at vitrinite reflectance measurements 0.9 Ro% at approximately 90 million years ago (Early Cenomanian). These similarities in geologic occurrences and biomarker characteristics suggest the possibility that the hydrocarbon expulsion would have been initiated from deeply buried Jurassic source rocks and trapped in the Pre-Laramide structures of Bahariya Formation throughout the extensional faults. (orig.)

  12. Modelling Chemical Patterns of Atmospheric Polycyclic Aromatic Hydrocarbons (PAHs) in the Iberian Peninsula

    Science.gov (United States)

    Ratola, Nuno; Jiménez-Guerrero, Pedro

    2013-04-01

    Semi-volatile organic compounds (SVOCs) such as PBDEs, PCBs, organochlorine pesticides (OCPs) or PAHs, are widespread and generated in a multitude of anthropogenic (and natural for PAHs) processes and although they are found in the environment at low concentrations, possess an extraordinary carcinogenic capacity (Baussant et al., 2001) and high ecotoxicity due to their persistence in different matrices (air, soil, water, living organisms). In particular, PAHs are originated by combustion processes or release from fossil fuels and can be transported in the atmosphere over long distances in gaseous or particulate matter (Baek et al., 1991). The establishment of strategies for sampling and chemical transport modelling of SVOCs in the atmosphere aiming the definition and validation of the spatial, temporal and chemical transport patterns of contaminants can be achieved by an integrated system of third-generation models that represent the current state of knowledge in air quality modelling and experimental data collected in field campaigns. This has implications in the fields of meteorology, atmospheric chemistry and even climate change. In this case, an extensive database already obtained on levels of atmospheric PAHs from biomonitoring schemes in the Iberian Peninsula fuelled the establishment of the first models of behaviour for PAHs. The modelling system WRF+CHIMERE was implemented with high spatial and temporal resolution to the Iberian Peninsula in this first task (9 km for the Iberian Peninsula, 3 km to Portugal, 1 hour), using PAHs atmospheric levels collected over a year-long sampling scheme comprising 4 campaigns (one per season) in over 30 sites. Daily information on meteorological parameters such as air temperature, humidity, rainfall or wind speed and direction was collected from the weather stations closest to the sampling sites. Diagnosis and forecasts of these meteorological variables using MM5 or WRF were used to feed a chemistry transport model

  13. Predicting Alkylate Yield and its Hydrocarbon Composition for Sulfuric Acid Catalyzed Isobutane Alkylation with Olefins Using the Method of Mathematical Modeling

    OpenAIRE

    Nurmakanova, А. Е.; Ivashkina, Elena Nikolaevna; Ivanchina, Emilia Dmitrievna; Dolganov, I. A.; Boychenko, S. S.

    2015-01-01

    The article provides the results of applied mathematical model of isobutane alkylation with olefins catalyzed by sulfuric acid to predict yield and hydrocarbon composition of alkylate caused by the changes in the feedstock composition and process parameters. It is shown that the alkylate produced from feedstock with less mass fraction of isobutane has lower octane value. Wherein the difference in composition of the feedstock contributes to antiknock index by the amount of 1.0-2.0 points.

  14. Comparative efficacy of tamsulosin versus tadalafil as medical expulsive therapy for distal ureteric stones.

    Science.gov (United States)

    Goyal, Suresh Kumar; Singh, Vikash; Pandey, Himanshu; Chhabra, Mahaveer Kumar; Aggarwal, Satinder Pal; Bhat, Amilal

    2018-01-01

    The objective of this study was to compare the relative efficacy of tamsulosin and tadalafil as medical expulsive therapy for distal ureteric stones. This was a prospective study performed between December 2014 and February 2016. A total of 123 adult patients (>18 years of age) presenting with distal ureteric stones sized 6-10 mm were randomized to treatment with tamsulosin 0.4 mg once daily (Group A) or tadalafil10 mg once daily (Group B). Therapy was given for a maximum of 4 weeks. The stone expulsion rate was the primary endpoint. Time to stone expulsion, number of colic episodes, analgesic use, number of hospital visits for pain, endoscopic treatment, and adverse effects of the drugs were noted. Statistical analyses were done using Fisher's exact test and Chi-square test. A total of 61 patients were included in tamsulosin group and 62 patients in tadalafil group. A statistically insignificant difference was found for stone clearance rate between both groups as a whole (Group A-73.77%, Group B-69.35%, P = 0.690) as well as when we considered both subgroups (A1-78.05%, B1-75.0%, P = 0.802; A2-65.0%, B2-55.6%, P = 0.741). All the primary and secondary outcome measures were more in favour of stones ≤8 mm size than stones >8 mm size. No statistical difference was found for adverse drug effects except for retrograde ejaculation, which was significantly high in tamsulosin group ( P tamsulosin is more effective for stone clearance than tadalafil, but this difference was not significant ( P = 0.690).

  15. The effect of inhibition of prostaglandin F2 alpha synthesis on placental expulsion in the ewe.

    Science.gov (United States)

    Chassagne, M; Barnouin, J

    1993-04-01

    Five ewes were injected with two doses of a nonsteroidal anti-inflammatory drug (NSAI), lysine acetyl salicylate, at birth of their first lamb and one hour later, and five others were injected once only, at birth of their first lamb. A control group of six animals was constituted. The times needed for fetal expulsion and placental release were recorded. The peripheral plasma PgF2 alpha (as PGFM) levels were measured prepartum during the seven last days of gestation, at parturition, then 1 h, 2 h and 12 h after lambing. The results were compared among and within treatment groups. They indicate that the physiological increase in peripheral PGFM levels starts two days before lambing and that the level peaks at lambing. The normal decrease after parturition is emphasized by NSAI injections as detected 1 h and 2 h posttreatment (p NSAI drug is short-acting as revealed by the lower PGFM levels in twice-treated animals 2 h after birth compared to once treated animals and the similar low levels in all three groups 12 h after birth. The fetal membranes were expelled normally in all treated and nontreated animals, but the time needed for placental expulsion in ewes injected with two doses of NSAI was longer than in controls (p < 0.05). A negative correlation (p < 0.05) was found between plasma PGFM levels measured two hours after lambing and the time needed for fetal membrane expulsion. PgF2 alpha appears to have a role in placental release in the ewe.

  16. The effect of inhibition of prostaglandin F2 alpha synthesis on placental expulsion in the ewe.

    OpenAIRE

    Chassagne, M; Barnouin, J

    1993-01-01

    Five ewes were injected with two doses of a nonsteroidal anti-inflammatory drug (NSAI), lysine acetyl salicylate, at birth of their first lamb and one hour later, and five others were injected once only, at birth of their first lamb. A control group of six animals was constituted. The times needed for fetal expulsion and placental release were recorded. The peripheral plasma PgF2 alpha (as PGFM) levels were measured prepartum during the seven last days of gestation, at parturition, then 1 h, ...

  17. Assessment of climate change impact on the fates of polycyclic aromatic hydrocarbons in the multimedia environment based on model prediction.

    Science.gov (United States)

    Cai, Juan Juan; Song, Jee Hey; Lee, Yunah; Lee, Dong Soo

    2014-02-01

    The objective was to quantitatively understand the impacts of climate change (CC) under the A1B scenario on the contamination levels of 11 polycyclic aromatic hydrocarbons (PAHs) from pyrogenic sources in the environmental media based on model prediction. To predict the impacts of CC in South Korea, a revised version of KoEFT-PBTs, a dynamic multimedia model for persistent organic pollutants in South Korea, was used. Simulations were conducted for the period from 2000 to 2049 under the A1B scenario with the emission data for 2009 and the results for Seoul and Kangwon were compared to those under no climate change (NCC) scenario. Due to CC, the average of annual or monthly average concentration changes within a factor of two for the PAHs in air, soil and water. Time dependent comparison indicates that the maximum increase induced by CC in the monthly average concentration ranges from 10 to 10(2) in air and water. Change in advective flux due to wind speed difference between A1B and NCC dictates the change of the atmospheric PAHs levels while wet particle deposition due to rain rate difference contributes to some extent to the change of 5 and 6 ring PAHs. Whether the concentration change is positive or not depends primarily on the emission strength of internal sources relative to those in surrounding areas. The CC induced changes in atmospheric depositions and degradation rate in soil play a leading role in the change of soil concentration. In water, runoff and degradation are the key processes to the CC induced concentration change. Both in soil and water, the relative importance of individual key processes varies with PAHs. The difference between the two scenarios in wind speed and in rain rate shows stronger correlations with the concentration change than the temperature change. © 2013 Elsevier B.V. All rights reserved.

  18. Modeling personal particle-bound polycyclic aromatic hydrocarbon (pb-pah) exposure in human subjects in Southern California.

    Science.gov (United States)

    Wu, Jun; Tjoa, Thomas; Li, Lianfa; Jaimes, Guillermo; Delfino, Ralph J

    2012-07-11

    Exposure to polycyclic aromatic hydrocarbon (PAH) has been linked to various adverse health outcomes. Personal PAH exposures are usually measured by personal monitoring or biomarkers, which are costly and impractical for a large population. Modeling is a cost-effective alternative to characterize personal PAH exposure although challenges exist because the PAH exposure can be highly variable between locations and individuals in non-occupational settings. In this study we developed models to estimate personal inhalation exposures to particle-bound PAH (PB-PAH) using data from global positioning system (GPS) time-activity tracking data, traffic activity, and questionnaire information. We conducted real-time (1-min interval) personal PB-PAH exposure sampling coupled with GPS tracking in 28 non-smoking women for one to three sessions and one to nine days each session from August 2009 to November 2010 in Los Angeles and Orange Counties, California. Each subject filled out a baseline questionnaire and environmental and behavior questionnaires on their typical activities in the previous three months. A validated model was used to classify major time-activity patterns (indoor, in-vehicle, and other) based on the raw GPS data. Multiple-linear regression and mixed effect models were developed to estimate averaged daily and subject-level PB-PAH exposures. The covariates we examined included day of week and time of day, GPS-based time-activity and GPS speed, traffic- and roadway-related parameters, meteorological variables (i.e. temperature, wind speed, relative humidity), and socio-demographic variables and occupational exposures from the questionnaire. We measured personal PB-PAH exposures for 180 days with more than 6 h of valid data on each day. The adjusted R2 of the model was 0.58 for personal daily exposures, 0.61 for subject-level personal exposures, and 0.75 for subject-level micro-environmental exposures. The amount of time in vehicle (averaging 4.5% of total

  19. Hydrocarbon pyrolysis reactor experimentation and modeling for the production of solar absorbing carbon nanoparticles

    Science.gov (United States)

    Frederickson, Lee Thomas

    Much of combustion research focuses on reducing soot particulates in emissions. However, current research at San Diego State University (SDSU) Combustion and Solar Energy Laboratory (CSEL) is underway to develop a high temperature solar receiver which will utilize carbon nanoparticles as a solar absorption medium. To produce carbon nanoparticles for the small particle heat exchange receiver (SPHER), a lab-scale carbon particle generator (CPG) has been built and tested. The CPG is a heated ceramic tube reactor with a set point wall temperature of 1100-1300°C operating at 5-6 bar pressure. Natural gas and nitrogen are fed to the CPG where natural gas undergoes pyrolysis resulting in carbon particles. The gas-particle mixture is met downstream with dilution air and sent to the lab scale solar receiver. To predict soot yield and general trends in CPG performance, a model has been setup in Reaction Design CHEMKIN-PRO software. One of the primary goals of this research is to accurately measure particle properties. Mean particle diameter, size distribution, and index of refraction are calculated using Scanning Electron Microscopy (SEM) and a Diesel Particulate Scatterometer (DPS). Filter samples taken during experimentation are analyzed to obtain a particle size distribution with SEM images processed in ImageJ software. These results are compared with the DPS, which calculates the particle size distribution and the index of refraction from light scattering using Mie theory. For testing with the lab scale receiver, a particle diameter range of 200-500 nm is desired. Test conditions are varied to understand effects of operating parameters on particle size and the ability to obtain the size range. Analysis of particle loading is the other important metric for this research. Particle loading is measured downstream of the CPG outlet and dilution air mixing point. The air-particle mixture flows through an extinction tube where opacity of the mixture is measured with a 532 nm

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

    Directory of Open Access Journals (Sweden)

    D. K. Henze

    2008-05-01

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

  1. Modeling flows of heterogeneous media in pipelines when substantiating operating conditions of hydrocarbon field transportation systems

    Science.gov (United States)

    Dudin, S. M.; Novitskiy, D. V.

    2018-05-01

    The works of researchers at VNIIgaz, Giprovostokneft, Kuibyshev NIINP, Grozny Petroleum Institute, etc., are devoted to modeling heterogeneous medium flows in pipelines under laboratory conditions. In objective consideration, the empirical relationships obtained and the calculation procedures for pipelines transporting multiphase products are a bank of experimental data on the problem of pipeline transportation of multiphase systems. Based on the analysis of the published works, the main design requirements for experimental installations designed to study the flow regimes of gas-liquid flows in pipelines were formulated, which were taken into account by the authors when creating the experimental stand. The article describes the results of experimental studies of the flow regimes of a gas-liquid mixture in a pipeline, and also gives a methodological description of the experimental installation. Also the article describes the software of the experimental scientific and educational stand developed with the participation of the authors.

  2. Modeling Parameters of Reliability of Technological Processes of Hydrocarbon Pipeline Transportation

    Directory of Open Access Journals (Sweden)

    Shalay Viktor

    2016-01-01

    Full Text Available On the basis of methods of system analysis and parametric reliability theory, the mathematical modeling of processes of oil and gas equipment operation in reliability monitoring was conducted according to dispatching data. To check the quality of empiric distribution coordination , an algorithm and mathematical methods of analysis are worked out in the on-line mode in a changing operating conditions. An analysis of physical cause-and-effect relations mechanism between the key factors and changing parameters of technical systems of oil and gas facilities is made, the basic types of technical distribution parameters are defined. Evaluation of the adequacy the analyzed parameters of the type of distribution is provided by using a criterion A.Kolmogorov, as the most universal, accurate and adequate to verify the distribution of continuous processes of complex multiple-technical systems. Methods of calculation are provided for supervising by independent bodies for risk assessment and safety facilities.

  3. Hydrocarbons prospecting using an integrated approach of petrography, geochemistry and modeling of organic matter transformation. Analysis and reconstitution of the thermal history of the central carboniferous basins of Asturias (Spain) and of the Sabinas - Piedras Negras basin (Coahuila, Mexico); Prospection des hydrocarbures par une approche integree de petrographie, geochimie et modelisation de la transformation de la matiere organique. Analyse et reconstitution de l'histoire thermique des Bassins Carbonifere Central des Asturies (Espagne) et Sabinas - Piedras Negras (Coahuila, Mexique)

    Energy Technology Data Exchange (ETDEWEB)

    Piedad-Sanchez, N.

    2004-09-01

    Solid knowledge of the transformation and evolution of organic matter during hydrocarbon generation in sedimentary basins serves to improve natural gas exploration. With this geological problem in mind, the thermal influence on organic matter was analyzed in two basins containing different characteristics (age, composition of organic matter, litho-stratigraphy, depth, thickness of the layers of rock, the maturation of organic matter, etc.) in order to understand the natural processes in generating oil and natural gas. With a view to studying this geological phenomenon, this work outlines the study of the chemical and macerals composition, the coal rank and geochemical characteristics of organic matter in these two sedimentary basins for the first time: The Asturian Central Carboniferous Basin (Spain) and Sabinas - Piedras Negras Basin (Mexico). Moreover, an approach to shed light on the thermal history and evolution of organic matter through 1D modeling in the two basins is developed. The Central Carboniferous Basin in Asturias is an important coal mining area where coal types range from bituminous carbons with high content in volatile matter to anthracite. The petrographical and geochemical study in this region has shown that at the moment of oil and gas exploration, the coals correspond to an efficient expulsion of oil and have been formed in an environment of swamp with a facies rich in vitrinite, low in sulfur and ash and varying in mineral content. As regards the paleo-environmental reconstruction, the bio-markers suggest a swamp with a relatively high water table and a humid climate. The coal type, the vitrinite reflectance and the volatile matter content in the basin show a N-S trend which could be correlated to the paleo-temperatures calculated in this study. These data point to the influence of two thermal gradients in the region: A normal thermal gradient of long duration and an oblique thermal gradient of short duration due to a pluton. The evolution of

  4. Evaluating officially reported polycyclic aromatic hydrocarbon emissions in the Athabasca oil sands region with a multimedia fate model

    Science.gov (United States)

    Parajulee, Abha; Wania, Frank

    2014-01-01

    Emissions of organic substances with potential toxicity to humans and the environment are a major concern surrounding the rapid industrial development in the Athabasca oil sands region (AOSR). Although concentrations of polycyclic aromatic hydrocarbons (PAHs) in some environmental samples have been reported, a comprehensive picture of organic contaminant sources, pathways, and sinks within the AOSR has yet to be elucidated. We sought to use a dynamic multimedia environmental fate model to reconcile the emissions and residue levels reported for three representative PAHs in the AOSR. Data describing emissions to air compiled from two official sources result in simulated concentrations in air, soil, water, and foliage that tend to fall close to or below the minimum measured concentrations of phenanthrene, pyrene, and benzo(a)pyrene in the environment. Accounting for evaporative emissions (e.g., from tailings pond disposal) provides a more realistic representation of PAH distribution in the AOSR. Such indirect emissions to air were found to be a greater contributor of PAHs to the AOSR atmosphere relative to reported direct emissions to air. The indirect pathway transporting uncontrolled releases of PAHs to aquatic systems via the atmosphere may be as significant a contributor of PAHs to aquatic systems as other supply pathways. Emission density estimates for the three PAHs that account for tailings pond disposal are much closer to estimated global averages than estimates based on the available emissions datasets, which fall close to the global minima. Our results highlight the need for improved accounting of PAH emissions from oil sands operations, especially in light of continued expansion of these operations. PMID:24596429

  5. Fluid expulsion sites on the Cascadia accretionary prism: mapping diagenetic deposits with processed GLORIA imagery

    Science.gov (United States)

    Carson, Bobb; Seke, Erol; Paskevich, Valerie F.; Holmes, Mark L.

    1994-01-01

    Point-discharge fluid expulsion on accretionary prisms is commonly indicated by diagenetic deposition of calcium carbonate cements and gas hydrates in near-surface (topographic and lithologic information. We have processed GLORIA imagery from the Oregon continental margin to remove topographic effects. A synthetic side scan image was created initially from Sea Beam bathymetric data and then was subtracted iteratively from the original GLORIA data until topographic features disappeared. The residual image contains high-amplitude backscattering that we attribute to diagenetic deposits associated with fluid discharge, based on submersible mapping, Ocean Drilling Program drilling, and collected samples. Diagenetic deposits are concentrated (1) near an out-of-sequence thrust fault on the second ridge landward of the base of the continental slope, (2) along zones characterized by deep-seated strikeslip faults that cut transversely across the margin, and (3) in undeformed Cascadia Basin deposits which overlie incipient thrust faults seaward of the toe of the prism. There is no evidence of diagenetic deposition associated with the frontal thrust that rises from the dècollement. If the dècollement is an important aquifer, apparently the fluids are passed either to the strike-slip faults which intersect the dècollement or to the incipient faults in Cascadia Basin for expulsion. Diagenetic deposits seaward of the prism toe probably consist dominantly of gas hydrates.

  6. Inducer expulsion in Streptococcus pyogenes: properties and mechanism of the efflux reaction

    International Nuclear Information System (INIS)

    Sutrina, S.L.; Reizer, J.; Saier, M.H Jr.

    1988-01-01

    Expulsion of preaccumulated methyl-β-D-thiogalactoside-phosphate (TMG-P) from Streptococcus pyogenes is a two-step process comprising intracellular dephosphorylation of TMG-P followed by rapid efflux of the intracellularly formed free galactoside. The present study identifies the mechanism and the order and characterizes the temperature dependency of the efflux step. Unidirectional efflux of the intracellularly formed [ 14 C]TMG was only slightly affected when measured in the presence of unlabeled TMG (25 to 400 mM) in the extracellular medium. In contrast, pronounced inhibition of net efflux was observed in the presence of relatively low concentrations (1 to 16 mM) of extracellular [ 14 C]TMG. Since net efflux was nearly arrested when the external concentration of [ 14 C]TMG approached the intracellular concentration of this sugar, we propose that a facilitated diffusion mechanism is responsible for efflux and equilibration of TMG between the intracellular and extracellular milieus. The exit reaction was markedly dependent upon temperature, exhibited a high energy of activation (23 kcal [ca. 96 kJ] per mol), and followed first-order kinetics, indicating that the permease mediating this efflux was not saturated under the conditions of expulsion employed

  7. Strongyloides ratti: implication of mast cell-mediated expulsion through FcεRI-independent mechanisms

    Directory of Open Access Journals (Sweden)

    Watanabe K.

    2009-09-01

    Full Text Available In order to examine whether FcεRI-dependent degranulation of intestinal mast cells is required for expulsion of intestinal nematode Strongyloides ratti, CD45 exon6-deficient (CD45-/- mice were inoculated with S. ratti. In CD45-/- mice, egg excretion in feces persisted for more than 30 days following S. ratti larvae inoculation, whereas in wild-type (CD45+/+ mice, the eggs completely disappeared by day 20 post-infection. The number of intestinal mucosal mast cells, which are known effector cells for the expulsion of S. ratti, was 75% lower in CD45-/- mice compared with that in CD45+/+ mice. Adoptive transfer of wild-type T cells from CD45+/+ mice into CD45-/- mice reduced the duration of S. ratti infection to comparable levels observed in CD45+/+ mice, with concomitant increases in intestinal mucosal mast cells. These results showed that CD45 is not involved in the effector function of intestinal mucosal mast cells against S. ratti infection. Since FcεRI-dependent degranulation of mast cells is completely impaired in these CD45 knockout mice, we conclude that FcεRIdependent degranulation is not required in the protective function of intestinal mucosal mast cells against primary infection of S. ratti.

  8. Modelling hydrothermal venting in volcanic sedimentary basins: Impact on hydrocarbon maturation and paleoclimate

    Science.gov (United States)

    Iyer, Karthik; Schmid, Daniel W.; Planke, Sverre; Millett, John

    2017-06-01

    Vent structures are intimately associated with sill intrusions in sedimentary basins globally and are thought to have been formed contemporaneously due to overpressure generated by gas generation during thermogenic breakdown of kerogen or boiling of water. Methane and other gases generated during this process may have driven catastrophic climate change in the geological past. In this study, we present a 2D FEM/FVM model that accounts for 'explosive' vent formation by fracturing of the host rock based on a case study in the Harstad Basin, offshore Norway. Overpressure generated by gas release during kerogen breakdown in the sill thermal aureole causes fracture formation. Fluid focusing and overpressure migration towards the sill tips results in vent formation after only few tens of years. The size of the vent depends on the region of overpressure accessed by the sill tip. Overpressure migration occurs in self-propagating waves before dissipating at the surface. The amount of methane generated in the system depends on TOC content and also on the type of kerogen present in the host rock. Generated methane moves with the fluids and vents at the surface through a single, large vent structure at the main sill tip matching first-order observations. Violent degassing takes place within the first couple of hundred years and occurs in bursts corresponding to the timing of overpressure waves. The amount of methane vented through a single vent is only a fraction (between 5 and 16%) of the methane generated at depth. Upscaling to the Vøring and Møre Basins, which are a part of the North Atlantic Igneous Province, and using realistic host rock carbon content and kerogen values results in a smaller amount of methane vented than previously estimated for the PETM. Our study, therefore, suggests that the negative carbon isotope excursion (CIE) observed in the fossil record could not have been caused by intrusions within the Vøring and Møre Basins alone and that a contribution

  9. Saskia Sassen, Expulsions. Brutalités et complexité dans l’économie globale

    OpenAIRE

    Lecadet, Clara

    2018-01-01

    Avec cet ouvrage, la sociologue américaine Saskia Sassen donne à la notion d’expulsion, généralement employée pour désigner les renvois d’étrangers en situation irrégulière ou les expulsions locatives, une portée générique. Les expulsions ont un sens à la fois politique, économique, social et écologique, constitutif d’une « limite systémique » (p. 281). L’auteure situe dans les années 1980 la phase de transition entre un modèle de type keynésien, qui avait permis l’essor à la fois de l’État-p...

  10. Essure insert expulsion after 3-month hysterosalpingogram confirmation of bilateral tubal occlusion and bilateral correct placement: case report.

    Science.gov (United States)

    Garcia, Amy L; Lewis, Rae M; Sloan, Anita Lee

    2013-01-01

    Essure hysteroscopic sterilization is an effective permanent contraception option for women, with a 99.83% effectiveness rate. To date, more than 600,000 Essure procedures have been performed worldwide. This case report describes bilateral Essure insert placement, after which the left insert was subsequently expelled after hysterosalpingogram (HSG)-confirmed correct bilateral insert placement and bilateral tubal occlusion. Although insert expulsion has been reported before a 3-month post-procedure HSG, this is the first published report of expulsion after a confirmatory 3-month post-procedure HSG. Because there now exists documentation of Essure insert expulsion after a 3-month confirmatory HSG, physicians and patients should be informed of this rare occurrence. Further investigation into the causes of such an event is warranted. Copyright © 2013 AAGL. Published by Elsevier Inc. All rights reserved.

  11. Effects of sodium chloride salting and substitution with potassium chloride on whey expulsion of Cheddar cheese.

    Science.gov (United States)

    Lu, Y; McMahon, D J

    2015-01-01

    A challenge in manufacturing reduced-sodium cheese is that whey expulsion after salting decreases when less salt is applied. Our objectives were (1) to determine whether changing the salting method would increase whey syneresis when making a lower sodium cheese and (2) to better understand factors contributing to salt-induced curd syneresis. Unsalted milled Cheddar curds were salted using different salting intervals (5 or 10 min), different salting levels (20, 25, or 30g/kg), different numbers of applications when using only 20g/kg salt (1, 2, or 3 applications), and salting with the equivalent of 30g/kg NaCl using a 2:1 molar ratio of NaCl and KCl. Whey from these curds was collected every 5 or 10 min until 30 or 40 min after the start of salting, and curds were subsequently pressed for 3h. Additional trials were conducted in which salted milled Cheddar cheese curd was immersed at 22°C for 6h in various solutions to determine how milled curd pieces respond to different levels of salt and Ca. The use of 10-min intervals delayed whey syneresis without influencing total whey expulsion or cheese composition after pressing. Lowering the salt level reduced whey expulsion, resulting in cheeses with higher moisture and slightly lower pH. Adding salt faster did not increase whey expulsion in reduced-salt cheese. Partial substitution with KCl restored the extent of whey expulsion. When salted milled curd was immersed in a 30g/L salt solution, there was a net influx of salt solution into the curd and curd weight increased. When curd was immersed in 60g/L salt solution, a contraction of curd occurred. Curd shrinkage was more pronounced as the salt solution concentration was increased to 90 and 120g/L. Increasing the Ca concentration in test solutions (such that both serum and total Ca in the curd increased) also promoted curd contraction, resulting in lower curd moisture and pH and less weight gain by the curd. The proportion of Ca in the curd that was bound to the para

  12. From axiomatics of quantum probability to modelling geological uncertainty and management of intelligent hydrocarbon reservoirs with the theory of open quantum systems

    Science.gov (United States)

    Lozada Aguilar, Miguel Ángel; Khrennikov, Andrei; Oleschko, Klaudia

    2018-04-01

    As was recently shown by the authors, quantum probability theory can be used for the modelling of the process of decision-making (e.g. probabilistic risk analysis) for macroscopic geophysical structures such as hydrocarbon reservoirs. This approach can be considered as a geophysical realization of Hilbert's programme on axiomatization of statistical models in physics (the famous sixth Hilbert problem). In this conceptual paper, we continue development of this approach to decision-making under uncertainty which is generated by complexity, variability, heterogeneity, anisotropy, as well as the restrictions to accessibility of subsurface structures. The belief state of a geological expert about the potential of exploring a hydrocarbon reservoir is continuously updated by outputs of measurements, and selection of mathematical models and scales of numerical simulation. These outputs can be treated as signals from the information environment E. The dynamics of the belief state can be modelled with the aid of the theory of open quantum systems: a quantum state (representing uncertainty in beliefs) is dynamically modified through coupling with E; stabilization to a steady state determines a decision strategy. In this paper, the process of decision-making about hydrocarbon reservoirs (e.g. `explore or not?'; `open new well or not?'; `contaminated by water or not?'; `double or triple porosity medium?') is modelled by using the Gorini-Kossakowski-Sudarshan-Lindblad equation. In our model, this equation describes the evolution of experts' predictions about a geophysical structure. We proceed with the information approach to quantum theory and the subjective interpretation of quantum probabilities (due to quantum Bayesianism). This article is part of the theme issue `Hilbert's sixth problem'.

  13. From axiomatics of quantum probability to modelling geological uncertainty and management of intelligent hydrocarbon reservoirs with the theory of open quantum systems.

    Science.gov (United States)

    Lozada Aguilar, Miguel Ángel; Khrennikov, Andrei; Oleschko, Klaudia

    2018-04-28

    As was recently shown by the authors, quantum probability theory can be used for the modelling of the process of decision-making (e.g. probabilistic risk analysis) for macroscopic geophysical structures such as hydrocarbon reservoirs. This approach can be considered as a geophysical realization of Hilbert's programme on axiomatization of statistical models in physics (the famous sixth Hilbert problem). In this conceptual paper , we continue development of this approach to decision-making under uncertainty which is generated by complexity, variability, heterogeneity, anisotropy, as well as the restrictions to accessibility of subsurface structures. The belief state of a geological expert about the potential of exploring a hydrocarbon reservoir is continuously updated by outputs of measurements, and selection of mathematical models and scales of numerical simulation. These outputs can be treated as signals from the information environment E The dynamics of the belief state can be modelled with the aid of the theory of open quantum systems: a quantum state (representing uncertainty in beliefs) is dynamically modified through coupling with E ; stabilization to a steady state determines a decision strategy. In this paper, the process of decision-making about hydrocarbon reservoirs (e.g. 'explore or not?'; 'open new well or not?'; 'contaminated by water or not?'; 'double or triple porosity medium?') is modelled by using the Gorini-Kossakowski-Sudarshan-Lindblad equation. In our model, this equation describes the evolution of experts' predictions about a geophysical structure. We proceed with the information approach to quantum theory and the subjective interpretation of quantum probabilities (due to quantum Bayesianism).This article is part of the theme issue 'Hilbert's sixth problem'. © 2018 The Author(s).

  14. The multichannel n-propyl + O2 reaction surface: Definitive theory on a model hydrocarbon oxidation mechanism

    Science.gov (United States)

    Bartlett, Marcus A.; Liang, Tao; Pu, Liang; Schaefer, Henry F.; Allen, Wesley D.

    2018-03-01

    The n-propyl + O2 reaction is an important model of chain branching reactions in larger combustion systems. In this work, focal point analyses (FPAs) extrapolating to the ab initio limit were performed on the n-propyl + O2 system based on explicit quantum chemical computations with electron correlation treatments through coupled cluster single, double, triple, and perturbative quadruple excitations [CCSDT(Q)] and basis sets up to cc-pV5Z. All reaction species and transition states were fully optimized at the rigorous CCSD(T)/cc-pVTZ level of theory, revealing some substantial differences in comparison to the density functional theory geometries existing in the literature. A mixed Hessian methodology was implemented and benchmarked that essentially makes the computations of CCSD(T)/cc-pVTZ vibrational frequencies feasible and thus provides critical improvements to zero-point vibrational energies for the n-propyl + O2 system. Two key stationary points, n-propylperoxy radical (MIN1) and its concerted elimination transition state (TS1), were located 32.7 kcal mol-1 and 2.4 kcal mol-1 below the reactants, respectively. Two competitive β-hydrogen transfer transition states (TS2 and TS2') were found separated by only 0.16 kcal mol-1, a fact unrecognized in the current combustion literature. Incorporating TS2' in master equation (ME) kinetic models might reduce the large discrepancy of 2.5 kcal mol-1 between FPA and ME barrier heights for TS2. TS2 exhibits an anomalously large diagonal Born-Oppenheimer correction (ΔDBOC = 1.71 kcal mol-1), which is indicative of a nearby surface crossing and possible nonadiabatic reaction dynamics. The first systematic conformational search of three hydroperoxypropyl (QOOH) intermediates was completed, uncovering a total of 32 rotamers lying within 1.6 kcal mol-1 of their respective lowest-energy minima. Our definitive energetics for stationary points on the n-propyl + O2 potential energy surface provide key benchmarks for future studies

  15. Comparison of three most frequently used alpha blocker agents in medical expulsive therapy for distal ureteral calculi, result of a retrospective observational study

    Directory of Open Access Journals (Sweden)

    Aykut Buğra Sentürk

    2018-03-01

    Full Text Available Purpose: In this study, we compared the effects of three agents frequently used in daily life for medical expulsive therapy. Materials and methods: A total of 143 patients meeting the criteria were included in the study. Patients were divided into three homogeneous drug groups which were tamsulosin group (n:48, alfuzosin group (n:47 and silodosin group (n:48. The time of stone expulsion, analgesic needs, side effects of the medicine and endoscopic intervention needs of the patients were recorded. Results: The rate of stone expulsion was 70.8% (n:34 in tamsulosin group, 70.2% (n:33 in alfuzosin group, and 75% (n:36 in silodosin group. No significant difference was observed among the rates of stone expulsion in three groups, and the rates of stone expulsion were similar (p = 0.778. The duration of stone expulsion was significantly different in the groups (p = 0.012: the time of stone expulsion for tamsulosin was 2.33 ± 0.78 days longer than for Silodosin, indicating a significant difference. There was no significant difference between tamsulosin-alfuzosin and silodosin-alfuzosin (respectively p = 0.147, p = 0.925. Conclusions: The results of this study showed that medical expulsive therapy by using alpha blocker agents is safe and efficacious. This option must be kept in mind for patients who do not ask for surgery as the first-step treatment for eligible patients.

  16. Modeling personal particle-bound polycyclic aromatic hydrocarbon (pb-pah exposure in human subjects in Southern California

    Directory of Open Access Journals (Sweden)

    Wu Jun

    2012-07-01

    Full Text Available Abstract Background Exposure to polycyclic aromatic hydrocarbon (PAH has been linked to various adverse health outcomes. Personal PAH exposures are usually measured by personal monitoring or biomarkers, which are costly and impractical for a large population. Modeling is a cost-effective alternative to characterize personal PAH exposure although challenges exist because the PAH exposure can be highly variable between locations and individuals in non-occupational settings. In this study we developed models to estimate personal inhalation exposures to particle-bound PAH (PB-PAH using data from global positioning system (GPS time-activity tracking data, traffic activity, and questionnaire information. Methods We conducted real-time (1-min interval personal PB-PAH exposure sampling coupled with GPS tracking in 28 non-smoking women for one to three sessions and one to nine days each session from August 2009 to November 2010 in Los Angeles and Orange Counties, California. Each subject filled out a baseline questionnaire and environmental and behavior questionnaires on their typical activities in the previous three months. A validated model was used to classify major time-activity patterns (indoor, in-vehicle, and other based on the raw GPS data. Multiple-linear regression and mixed effect models were developed to estimate averaged daily and subject-level PB-PAH exposures. The covariates we examined included day of week and time of day, GPS-based time-activity and GPS speed, traffic- and roadway-related parameters, meteorological variables (i.e. temperature, wind speed, relative humidity, and socio-demographic variables and occupational exposures from the questionnaire. Results We measured personal PB-PAH exposures for 180 days with more than 6 h of valid data on each day. The adjusted R2 of the model was 0.58 for personal daily exposures, 0.61 for subject-level personal exposures, and 0.75 for subject-level micro-environmental exposures. The amount

  17. Converting high boiling hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Terrisse, H; DuFour, L

    1929-02-12

    A process is given for converting high boiling hydrocarbons into low boiling hydrocarbons, characterized in that the high boiling hydrocarbons are heated to 200 to 500/sup 0/C in the presence of ferrous chloride and of such gases as hydrogen, water gas, and the like gases under a pressure of from 5 to 40 kilograms per square centimeter. The desulfurization of the hydrocarbons occurs simultaneously.

  18. Modeling land subsidence due to shallow-water hydrocarbon production: A case study in the northern Adriatic Sea

    Science.gov (United States)

    Gambolati, G.; Castelletto, N.; Ferronato, M.; Janna, C.; Teatini, P.

    2012-12-01

    One major environmental concern of subsurface fluid withdrawal is land subsidence. The issue of a reliable estimate and prediction of the expected anthropogenic land subsidence is particularly important whenever the production of hydrocarbon (oil and gas) occurs from large reservoirs located close to deltaic zones (e.g., Mississippi, Po, Nile, Niger, Yellow rivers) or shallow-water with low-lying coastlands (e.g., Northern Caspian sea, Dutch Wadden Sea). In such cases even a small reduction of the ground elevation relative to the mean sea level may impact seriously on human settlements and natural environment. The monitoring of the ongoing land subsidence has been significantly improved over the last decade by SAR-based interferometry. These measurements can be quite effectively used to map the process and calibrate geomechanical models for predicting the future event. However, this powerful methodology cannot be implemented off-shore. Although permanent GPS stations can be established to monitor the movement of the production facilities usually installed above the gravity center of a reservoir, an accurate characterization of the settlement bowl affecting the sea bottom, with a possible migration toward the shore, is a challenge still today. In the present communication the case study of the Riccione gas reservoir is discussed. The field is located in the near-shore northern Adriatic Sea, approximately 15 km far from the coastline, where the seawater height is about 20 m. The gas-bearing strata are 1100 m deep and are hydraulically connected to a relatively weak aquifer. Production of 70% of the cumulative reserves as of 2006 yielded a pore pressure decrease of 60 bars. Reliable geometry and geomechanical properties of the depleted formations were detected with the aid of a 3D seismic survey and a borehole equipped with radioactive markers, respectively. The latter pointed out that the Riccione formations are characterized by an unusually high oedometer

  19. Sushruta in 600 B.C. introduced extraocular expulsion of lens material.

    Science.gov (United States)

    Grzybowski, Andrzej; Ascaso, Francisco J

    2014-03-01

    It is generally accepted that Jacques Daviel introduced in the 18th century the extracapsular technique of extraction of the lens while the couching method of cataract operation had already been practiced since ancient times. Present study analyses the first known cataract surgery description in three translations into English from the original Sanskrit Sushruta textbook and all the available literature on the subject. We found evidences that some sort of extraocular expulsion of lens material through a limbal puncture (paracentesis) was described by the Indian surgeon. Nevertheless, this incision cannot be considered as a classic extracapsular procedure because it was not large enough to allow the extraction of the entire lens. © 2013 The Authors. Acta Ophthalmologica © 2012 Acta Ophthalmologica Scandinavica Foundation.

  20. Immune expulsion of Trichuris muris from resistant mice: suppression by irradiation and restoration by transfer of lymphoid cells

    International Nuclear Information System (INIS)

    Wakelin, D.; Selby, G.R.

    1976-01-01

    Lethal irradiation (850 rads of x rays) of mice made resistant to Trichuris muris markedly depressed their ability to expel a challenge infection. Expulsion was restored within 7 to 10 days when MLNC from uninfected mice were transferred on the day of infection, but no significant restoration was evident after transfer of immune serum. Transfer of Bm alone had no restorative effect within 10 days and no synergism was seen when both BM and MLNC were transferred. MLNC from uninfected donors did not restore challenge expulsion when transfer was delayed until day 7 and the mice were killed 3 days later, although MLNC from resistant donors were effective within this time. When irradiated mice were given BM and the challenge infection allowed to continue for 15 days expulsion was restored, as it was when challenge was delayed for 7 days after BM transfer in thymectomized mice. The results confirm that expulsion of T. muris involves both antibody-mediated and lymphoid cell-mediated phases and offer no evidence for the involvement of other cell types. (author)

  1. Preschool Teachers' Responses to Challenging Behavior: The Role of Organizational Climate in Referrals and Expulsions

    Science.gov (United States)

    Miller, Shauna; Smith-Bonahue, Tina; Kemple, Kristen

    2017-01-01

    Challenging behavior in preschool can lead to harmful outcomes for some children. While interventions have been shown to be effective in reducing or eliminating challenging behavior, evidence suggests that young children with challenging behavior are under-identified for services, increasing their risk for expulsion from early childhood programs.…

  2. Parturition in gilts: duration of farrowing, birth intervals and placenta expulsion in relation to maternal, piglet and placental traits

    NARCIS (Netherlands)

    Rens, van B.T.T.M.; Lende, van der T.

    2004-01-01

    Large White×Meishan F2 crossbred gilts (n=57) were observed continuously during farrowing while the placentae of their offspring were labeled in order to examine the duration of farrowing and placenta expulsion in relation to maternal-, piglet- and placental traits and the duration of birth interval

  3. Children in Crisis: Special Education Status and Other Stressors in the Lives of Children Removed from School by Expulsion

    Science.gov (United States)

    Edmonds-Cady, Cynthia; Hock, Robert

    2008-01-01

    This exploratory qualitative study examines what occurred in the lives of kindergarten through twelfth-grade students who were expelled from school in order to understand possible stressors in their lives. Data were obtained on expulsion cases from a variety of school districts in one midwestern state. The sample (N = 91) consisted of the total…

  4. Moderate Thermal Stress Causes Active and Immediate Expulsion of Photosynthetically Damaged Zooxanthellae (Symbiodinium from Corals.

    Directory of Open Access Journals (Sweden)

    Lisa Fujise

    Full Text Available The foundation of coral reef biology is the symbiosis between corals and zooxanthellae (dinoflagellate genus Symbiodinium. Recently, coral bleaching, which often results in mass mortality of corals and the collapse of coral reef ecosystems, has become an important issue around the world as coral reefs decrease in number year after year. To understand the mechanisms underlying coral bleaching, we maintained two species of scleractinian corals (Acroporidae in aquaria under non-thermal stress (27°C and moderate thermal stress conditions (30°C, and we compared the numbers and conditions of the expelled Symbiodinium from these corals. Under non-thermal stress conditions corals actively expel a degraded form of Symbiodinium, which are thought to be digested by their host coral. This response was also observed at 30°C. However, while the expulsion rates of Symbiodinium cells remained constant, the proportion of degraded cells significantly increased at 30°C. This result indicates that corals more actively digest and expel damaged Symbiodinium under thermal stress conditions, likely as a mechanism for coping with environmental change. However, the increase in digested Symbiodinium expulsion under thermal stress may not fully keep up with accumulation of the damaged cells. There are more photosynthetically damaged Symbiodinium upon prolonged exposure to thermal stress, and corals release them without digestion to prevent their accumulation. This response may be an adaptive strategy to moderate stress to ensure survival, but the accumulation of damaged Symbiodinium, which causes subsequent coral deterioration, may occur when the response cannot cope with the magnitude or duration of environmental stress, and this might be a possible mechanism underlying coral bleaching during prolonged moderate thermal stress.

  5. Moderate Thermal Stress Causes Active and Immediate Expulsion of Photosynthetically Damaged Zooxanthellae (Symbiodinium) from Corals.

    Science.gov (United States)

    Fujise, Lisa; Yamashita, Hiroshi; Suzuki, Go; Sasaki, Kengo; Liao, Lawrence M; Koike, Kazuhiko

    2014-01-01

    The foundation of coral reef biology is the symbiosis between corals and zooxanthellae (dinoflagellate genus Symbiodinium). Recently, coral bleaching, which often results in mass mortality of corals and the collapse of coral reef ecosystems, has become an important issue around the world as coral reefs decrease in number year after year. To understand the mechanisms underlying coral bleaching, we maintained two species of scleractinian corals (Acroporidae) in aquaria under non-thermal stress (27°C) and moderate thermal stress conditions (30°C), and we compared the numbers and conditions of the expelled Symbiodinium from these corals. Under non-thermal stress conditions corals actively expel a degraded form of Symbiodinium, which are thought to be digested by their host coral. This response was also observed at 30°C. However, while the expulsion rates of Symbiodinium cells remained constant, the proportion of degraded cells significantly increased at 30°C. This result indicates that corals more actively digest and expel damaged Symbiodinium under thermal stress conditions, likely as a mechanism for coping with environmental change. However, the increase in digested Symbiodinium expulsion under thermal stress may not fully keep up with accumulation of the damaged cells. There are more photosynthetically damaged Symbiodinium upon prolonged exposure to thermal stress, and corals release them without digestion to prevent their accumulation. This response may be an adaptive strategy to moderate stress to ensure survival, but the accumulation of damaged Symbiodinium, which causes subsequent coral deterioration, may occur when the response cannot cope with the magnitude or duration of environmental stress, and this might be a possible mechanism underlying coral bleaching during prolonged moderate thermal stress.

  6. Cross of Lorraine and Cross of Caravaca: new IUD's with low expulsion rates.

    Science.gov (United States)

    Coutinho, E M; Mascarenhas, M J

    1985-01-01

    The Cross of Caravaca and Cross of Lorraine IUDs with double horizontal bar design were developed in an attempt to reduce expulsion and removal rates for pain and bleeding encountered with other IUDs. The devices were manufactured in radio-opaque plastic bearing copper wire or sleeves on the top arm. The Cross of Lorraine has the upper arm shorter than the lower arm whereas in the Cross of Caravaca the shorter is the lower arm. 748 women had insertion of the Cross of Caravaca and 412 had insertion of the Cross of Lorraine. For the Cross of Caravaca 486 women completed 1 year of use, 392 completed 2 years and 310 completed 3 years. For the Cross of Lorraine, 268 women completed the 1st year, 205 the 2nd, and 150 women completed 3 years of use. The combined number of observed months of use for the 2 devices at the end of 3 years was 24,963. Accidental pregnancy rates at the end of 3 years were 1.13% for Caravaca and 3.48% for Lorraine. Expulsion rates at the end of 3 years were nil for the Cross of Lorraine and 1.16% for the Cross of Caravaca. Pain and bleeding were the most common causes of termination for medical reasons, bleeding accounting for termination in 1.66% of Lorraine users at the end of 3 years of use and 2.75% of Caravaca users. Pain accounted for termination in 3.14% of Caravaca users and 2.02% of Lorraine users. Incidence of infection was 0.42% and nil for Caravaca and Lorraine users respectively. Total discontinuation rates at the end of 3 years were 25.39% for Caravaca and 16.67% for Lorraine.

  7. A study on the expulsion of iodine from spent-fuel solutions

    Energy Technology Data Exchange (ETDEWEB)

    Sakurai, Tsutomu; Takahashi, Akira; Ishikawa, Niroh [Japan Atomic Energy Research Institute, Ibaraki-ken (Japan)] [and others

    1995-02-01

    During dissolution of spent nuclear fuels, some radioiodine remains in spent-fuel solutions. Its expulsion to dissolver off-gas is important to minimize iodine escape to the environment. In our current work, the iodine remaining in spent-fuel solutions varied from 0 to 10% after dissolution of spent PWR-fuel specimens (approximately 3 g each). The amount remaining probably was dependent upon the dissolution time required. The cause is ascribable to the increased nitrous acid concentration that results from NOx generated during dissolution. The presence of nitrous acid was confirmed spectrophotometrically in an NO-HNO{sub 3} system at 100{degrees}C. Experiments examining NOx concentration versus the quantity of iodine in a simulated spent-fuel solution indicate that iodine (I{minus}) in spent fuels is subjected to the following three reactions: (1) oxidation into I{sub 2} by nitric acid, (2) oxidation into I{sub 2} by nitrous acid arising from NOx, and (3) formation of colloidal iodine (AgI, PdI{sub 2}), the major iodine species in a spent-fuel solution. Reaction (2) competes with reaction (3) to control the quantity of iodine remaining in solution. The following two-step expulsion process to remove iodine from a spent-fuel solution was derived from these experiments: Step One - Heat spent-fuel solutions without NOx sparging. When aged colloidal iodine is present, an excess amount of iodate should be added to the solution. Step Two - Sparge the fuel solution with NOx while heating. Effect of this new method was confirmed by use of a spent PWR-fuel solution.

  8. Inducible deletion of CD28 prior to secondary nippostrongylus brasiliensis infection impairs worm expulsion and recall of protective memory CD4⁺ T cell responses.

    Directory of Open Access Journals (Sweden)

    Hlumani Ndlovu

    2014-02-01

    Full Text Available IL-13 driven Th2 immunity is indispensable for host protection against infection with the gastrointestinal nematode Nippostronglus brasiliensis. Disruption of CD28 mediated costimulation impairs development of adequate Th2 immunity, showing an importance for CD28 during the initiation of an immune response against this pathogen. In this study, we used global CD28⁻/⁻ mice and a recently established mouse model that allows for inducible deletion of the cd28 gene by oral administration of tamoxifen (CD28(-/loxCre⁺/⁻+TM to resolve the controversy surrounding the requirement of CD28 costimulation for recall of protective memory responses against pathogenic infections. Following primary infection with N. brasiliensis, CD28⁻/⁻ mice had delayed expulsion of adult worms in the small intestine compared to wild-type C57BL/6 mice that cleared the infection by day 9 post-infection. Delayed expulsion was associated with reduced production of IL-13 and reduced serum levels of antigen specific IgG1 and total IgE. Interestingly, abrogation of CD28 costimulation in CD28(-/loxCre⁺/⁻ mice by oral administration of tamoxifen prior to secondary infection with N. brasiliensis resulted in impaired worm expulsion, similarly to infected CD28⁻/⁻ mice. This was associated with reduced production of the Th2 cytokines IL-13 and IL-4, diminished serum titres of antigen specific IgG1 and total IgE and a reduced CXCR5⁺ T(FH cell population. Furthermore, total number of CD4⁺ T cells and B220⁺ B cells secreting Th1 and Th2 cytokines were significantly reduced in CD28⁻/⁻ mice and tamoxifen treated CD28(-/loxCre⁺/⁻ mice compared to C57BL/6 mice. Importantly, interfering with CD28 costimulatory signalling before re-infection impaired the recruitment and/or expansion of central and effector memory CD4⁺ T cells and follicular B cells to the draining lymph node of tamoxifen treated CD28(-/loxCre⁺/⁻ mice. Therefore, it can be concluded that CD28

  9. Surgically Implanted JSATS Micro-Acoustic Transmitters Effects on Juvenile Chinook Salmon and Steelhead Tag Expulsion and Survival, 2010

    Energy Technology Data Exchange (ETDEWEB)

    Woodley, Christa M.; Carpenter, Scott M.; Carter, Kathleen M.; Wagner, Katie A.; Royer, Ida M.; Knox, Kasey M.; Kim, Jin A.; Gay, Marybeth E.; Weiland, Mark A.; Brown, Richard S.

    2011-09-16

    The purpose of this study was to evaluate survival model assumptions associated with a concurrent study - Acoustic Telemetry Evaluation of Dam Passage Survival and Associated Metrics at John Day, The Dalles, and Bonneville Dams, 2010 by Thomas Carlson and others in 2010 - in which the Juvenile Salmonid Acoustic Telemetry System (JSATS) was used to estimate the survival of yearling and subyearling Chinook salmon (Oncorhynchus tshawytscha) and steelhead (O. mykiss) migrating through the Federal Columbia River Power System (FCRPS). The micro-acoustic transmitter used in these studies is the smallest acoustic transmitter model to date (12 mm long x 5 mm wide x 4 mm high, and weighing 0.43 g in air). This study and the 2010 study by Carlson and others were conducted by researchers from the Pacific Northwest National Laboratory and the University of Washington for the U.S. Army Corps of Engineers, Portland District, to meet requirements set forth by the 2008 FCRPS Biological Opinion. In 2010, we compared survival, tag burden, and tag expulsion in five spring groups of yearling Chinook salmon (YCH) and steelhead (STH) and five summer groups of subyearling Chinook salmon (SYC) to evaluate survival model assumptions described in the concurrent study. Each tagging group consisted of approximately 120 fish/species, which were collected and implanted on a weekly basis, yielding approximately 600 fish total/species. YCH and STH were collected and implanted from late April to late May (5 weeks) and SYC were collected and implanted from mid-June to mid-July (5 weeks) at the John Day Dam Smolt Monitoring Facility. The fish were collected once a week, separated by species, and assigned to one of three treatment groups: (1) Control (no surgical treatment), (2) Sham (surgical implantation of only a passive integrated transponder [PIT] tag), and (3) Tagged (surgical implantation of JSATS micro-acoustic transmitter [AT] and PIT tags). The test fish were held for 30 days in indoor

  10. Comparison of two association models (Elliott-Suresh-Donohue and simplified PC-SAFT) for complex phase equilibria of hydrocarbon-water and amine-containing mixtures

    DEFF Research Database (Denmark)

    Grenner, Andreas; Schmelzer, Jürgen; von Solms, Nicolas

    2006-01-01

    , and water. Furthermore, the predictive capabilities of the models are investigated for four ternary systems composed of these components, which exhibit complex liquid-liquid(-liquid) equilibria (LLLE). Various aspects of association models which have an influence in the results are studied for the PC......, both models perform overall similarly for the binary systems, although ESD shows a remarkably good behavior despite its simplicity and the use of only the two-site scheme for all associating compounds. The prediction of the LLE in the ternary systems water + octane + aniline and water + CHA + aniline......Two Wertheim-based association models, the simplified PC-SAFT and the Elliott-Suresh-Donohue (ESD) equation of state, are compared in this work for the description of vapor-liquid equilibria (VLE) and liquid-liquid equilibria (LLE) in binary systems of aniline, cyclohexylamine (CHA), hydrocarbons...

  11. Hydrocarbons: source of energy

    International Nuclear Information System (INIS)

    Imarisio, G.; Frias, M.; Bemtgen, J.M.

    1989-01-01

    Hydrocarbons are at present the single most important source of energy, since they are the most versatile and widely used. It is expected that their importance will extend well into the next century and therefore it is essential to provide for all those improvements which will extend their availability and usefulness. The sub-programme ''Optimization of the production and utilization of hydrocarbons'' (within the Non-Nuclear Energy R and D Programme of the European Communities) is pursuing a number of R and D topics aimed at the above-mentioned results. It is implemented by means of shared-cost R and D contracts. At this first Seminar held in Lyon (France) from 21-23 September, 1988, all contractors of the sub-programme presented the state of progress of their R and D projects. These proceedings comprise all the papers presented at the Seminar. The section on oilfield exploration includes a report of work on the interpretation of nuclear logs by means of mathematical models. (author)

  12. Characterization of hydrocarbon utilizing fungi from hydrocarbon ...

    African Journals Online (AJOL)

    Prof. Ogunji

    isolated fungi could be useful in the bioremediation of hydrocarbon polluted sites. Keywords: ... Technologies such as mechanical force, burying, evaporation, dispersant application, and ..... The effects of drilling fluids on marine bacteria from a.

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

    Directory of Open Access Journals (Sweden)

    Tissot B. P.

    2006-11-01

    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.

  14. Hydrocarbons and air pollution

    International Nuclear Information System (INIS)

    Herz, O.

    1992-01-01

    This paper shows the influence of hydrocarbons vapors, emitted by transports or by volatile solvents using, on air pollution. Hydrocarbons are the principal precursors of photochemical pollution. After a brief introduction on atmospheric chemistry and photochemical reactions, the author describes the french prevention program against hydrocarbons emissions. In the last chapter, informations on international or european community programs for photochemical pollution study are given. 5 figs., 10 tabs

  15. Production of hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Day, D T; Day, R E

    1920-04-27

    A process is disclosed of converting hydro-carbon oils having high boiling points to hydro-carbon oils having low boiling points, which process comprises adding the oil to be treated to a mass of hydro-carbon oil bearing shale, passing the shale with the oil through a conveyor retort and subjecting the material while in the retort to a heat treatment involving a temperature of at least 500/sup 0/F.

  16. Does the concept of Clar's aromatic sextet work for dicationic forms of polycyclic aromatic hydrocarbons?--testing the model against charged systems in singlet and triplet states.

    Science.gov (United States)

    Dominikowska, Justyna; Palusiak, Marcin

    2011-07-07

    The concept of Clar's π-electron aromatic sextet was tested against a set of polycyclic aromatic hydrocarbons in neutral and doubly charged forms. Systems containing different types of rings (in the context of Clar's concept) were chosen, including benzene, naphthalene, anthracene, phenanthrene and triphenylene. In the case of dicationic structures both singlet and triplet states were considered. It was found that for singlet state dicationic structures the concept of aromatic sextet could be applied and the local aromaticity could be discussed in the context of that model, whereas in the case of triplet state dicationic structures Clar's model rather failed. Different aromaticity indices based on various properties of molecular systems were applied for the purpose of the studies. The discussion about the interdependence between the values of different aromaticity indices applied to neutral and charged systems in singlet and triplet states is also included. This journal is © the Owner Societies 2011

  17. Application of a fuzzy neural network model in predicting polycyclic aromatic hydrocarbon-mediated perturbations of the Cyp1b1 transcriptional regulatory network in mouse skin

    Energy Technology Data Exchange (ETDEWEB)

    Larkin, Andrew [Department of Environmental and Molecular Toxicology, Oregon State University (United States); Department of Statistics, Oregon State University (United States); Superfund Research Center, Oregon State University (United States); Siddens, Lisbeth K. [Department of Environmental and Molecular Toxicology, Oregon State University (United States); Superfund Research Center, Oregon State University (United States); Krueger, Sharon K. [Superfund Research Center, Oregon State University (United States); Linus Pauling Institute, Oregon State University (United States); Tilton, Susan C.; Waters, Katrina M. [Superfund Research Center, Oregon State University (United States); Computational Biology and Bioinformatics Group, Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Williams, David E., E-mail: david.williams@oregonstate.edu [Department of Environmental and Molecular Toxicology, Oregon State University (United States); Superfund Research Center, Oregon State University (United States); Linus Pauling Institute, Oregon State University (United States); Environmental Health Sciences Center, Oregon State University, Corvallis, OR 97331 (United States); Baird, William M. [Department of Environmental and Molecular Toxicology, Oregon State University (United States); Superfund Research Center, Oregon State University (United States); Environmental Health Sciences Center, Oregon State University, Corvallis, OR 97331 (United States)

    2013-03-01

    Polycyclic aromatic hydrocarbons (PAHs) are present in the environment as complex mixtures with components that have diverse carcinogenic potencies and mostly unknown interactive effects. Non-additive PAH interactions have been observed in regulation of cytochrome P450 (CYP) gene expression in the CYP1 family. To better understand and predict biological effects of complex mixtures, such as environmental PAHs, an 11 gene input-1 gene output fuzzy neural network (FNN) was developed for predicting PAH-mediated perturbations of dermal Cyp1b1 transcription in mice. Input values were generalized using fuzzy logic into low, medium, and high fuzzy subsets, and sorted using k-means clustering to create Mamdani logic functions for predicting Cyp1b1 mRNA expression. Model testing was performed with data from microarray analysis of skin samples from FVB/N mice treated with toluene (vehicle control), dibenzo[def,p]chrysene (DBC), benzo[a]pyrene (BaP), or 1 of 3 combinations of diesel particulate extract (DPE), coal tar extract (CTE) and cigarette smoke condensate (CSC) using leave-one-out cross-validation. Predictions were within 1 log{sub 2} fold change unit of microarray data, with the exception of the DBC treatment group, where the unexpected down-regulation of Cyp1b1 expression was predicted but did not reach statistical significance on the microarrays. Adding CTE to DPE was predicted to increase Cyp1b1 expression, whereas adding CSC to CTE and DPE was predicted to have no effect, in agreement with microarray results. The aryl hydrocarbon receptor repressor (Ahrr) was determined to be the most significant input variable for model predictions using back-propagation and normalization of FNN weights. - Highlights: ► Tested a model to predict PAH mixture-mediated changes in Cyp1b1 expression ► Quantitative predictions in agreement with microarrays for Cyp1b1 induction ► Unexpected difference in expression between DBC and other treatments predicted ► Model predictions

  18. Achievement of high diode sensitivity via spin torque-induced resonant expulsion in vortex magnetic tunnel junction

    Science.gov (United States)

    Tsunegi, Sumito; Taniguchi, Tomohiro; Yakushiji, Kay; Fukushima, Akio; Yuasa, Shinji; Kubota, Hitoshi

    2018-05-01

    We investigated the spin-torque diode effect in a magnetic tunnel junction with FeB free layer. Vortex-core expulsion was observed near the boundary between vortex and uniform states. A high diode voltage of 24 mV was obtained with alternative input power of 0.3 µW, corresponding to huge diode sensitivity of 80,000 mV/mW. In the expulsion region, a broad peak in the high frequency region was observed, which is attributed to the weak excitation of uniform magnetization by thermal noise. The high diode sensitivity is of great importance for device applications such as telecommunications, radar detectors, and high-speed magnetic-field sensors.

  19. Uptake and expulsion of sup 14 C-xylitol by xylitol-cultured Streptococcus mutans ATCC 25175 in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Soederling, E.; Pihlanto-Leppaelae, A. (Department of Biochemistry, Institute of Dentistry, University of Turku, Turku (Finland))

    1989-01-01

    The effect of successive cultivations in the presence of 6% xylitol on the uptake and expulsion of {sup 14}C-xylitol was studied using the cells of Streptococcus mutans 25175. Three sequential cultivations did not alter the growth inhibition percentage (approximately 50%) observed in the presence of 6% xylitol. The {sup 14}C-xylitol uptake experiments performed with growing and resting cells showed that both the uptake and the expulsion of xylitol were enhanced by xylitolculturing. Both xylitol-cultured and resting control cells contained only one major labeled compound which was identified as {sup 14}C-xylitol 5-phosphate. The label subsequently was expelled from the cells as {sup 14}C-xylitol. These results indicate that S. mutans possesses an intracellular xylitol cycle and this cycle is regulated by adding xylitol to the growth medium. (author).

  20. Uptake and expulsion of 14C-xylitol by xylitol-cultured Streptococcus mutans ATCC 25175 in vitro

    International Nuclear Information System (INIS)

    Soederling, E.; Pihlanto-Leppaelae, A.

    1989-01-01

    The effect of successive cultivations in the presence of 6% xylitol on the uptake and expulsion of 14 C-xylitol was studied using the cells of Streptococcus mutans 25175. Three sequential cultivations did not alter the growth inhibition percentage (approximately 50%) observed in the presence of 6% xylitol. The 14 C-xylitol uptake experiments performed with growing and resting cells showed that both the uptake and the expulsion of xylitol were enhanced by xylitolculturing. Both xylitol-cultured and resting control cells contained only one major labeled compound which was identified as 14 C-xylitol 5-phosphate. The label subsequently was expelled from the cells as 14 C-xylitol. These results indicate that S. mutans possesses an intracellular xylitol cycle and this cycle is regulated by adding xylitol to the growth medium. (author)

  1. Anomalous water expulsion from carbon-based rods at high humidity

    Science.gov (United States)

    Nune, Satish K.; Lao, David B.; Heldebrant, David J.; Liu, Jian; Olszta, Matthew J.; Kukkadapu, Ravi K.; Gordon, Lyle M.; Nandasiri, Manjula I.; Whyatt, Greg; Clayton, Chris; Gotthold, David W.; Engelhard, Mark H.; Schaef, Herbert T.

    2016-09-01

    Three water adsorption-desorption mechanisms are common in inorganic materials: chemisorption, which can lead to the modification of the first coordination sphere; simple adsorption, which is reversible; and condensation, which is irreversible. Regardless of the sorption mechanism, all known materials exhibit an isotherm in which the quantity of water adsorbed increases with an increase in relative humidity. Here, we show that carbon-based rods can adsorb water at low humidity and spontaneously expel about half of the adsorbed water when the relative humidity exceeds a 50-80% threshold. The water expulsion is reversible, and is attributed to the interfacial forces between the confined rod surfaces. At wide rod spacings, a monolayer of water can form on the surface of the carbon-based rods, which subsequently leads to condensation in the confined space between adjacent rods. As the relative humidity increases, adjacent rods (confining surfaces) in the bundles are drawn closer together via capillary forces. At high relative humidity, and once the size of the confining surfaces has decreased to a critical length, a surface-induced evaporation phenomenon known as solvent cavitation occurs and water that had condensed inside the confined area is released as a vapour.

  2. The Expulsion of South Africa and Rhodesia from the Commonwealth Medical Association, 1947–70

    Science.gov (United States)

    Stewart, John

    2017-01-01

    In 1970 the medical associations of South Africa and Rhodesia (now, Zimbabwe) were expelled from the Commonwealth Medical Association. The latter had been set up, as the British Medical Commonwealth Medical Conference, in the late 1940s by the British Medical Association (BMA). These expulsions, and the events leading up to them, are the central focus of this article. The BMA’s original intention was to establish an organisation bringing together the medical associations of the constituent parts of the expanding Commonwealth. Among the new body’s preoccupations was the relationship between the medical profession and the state in the associations’ respective countries. It thus has to be seen as primarily a medico-political organisation rather than one concerned with medicine per se. Although, there were also tensions from the outset regarding the membership of the Southern African medical associations. Such stresses notwithstanding, these two organisations remained in the BMA-sponsored body even after South Africa and Rhodesia had left the Commonwealth. This was not, however, a situation which could outlast the growing number of African associations which joined in the wake of decolonisation; and hardening attitudes towards apartheid. The article therefore considers: why the BMA set up this Commonwealth body in the first place and what it hoped to achieve; the history of the problems associated with South African and Rhodesian membership; and how their associations came to be expelled. PMID:28901869

  3. The Expulsion of South Africa and Rhodesia from the Commonwealth Medical Association, 1947-70.

    Science.gov (United States)

    Stewart, John

    2017-10-01

    In 1970 the medical associations of South Africa and Rhodesia (now, Zimbabwe) were expelled from the Commonwealth Medical Association. The latter had been set up, as the British Medical Commonwealth Medical Conference, in the late 1940s by the British Medical Association (BMA). These expulsions, and the events leading up to them, are the central focus of this article. The BMA's original intention was to establish an organisation bringing together the medical associations of the constituent parts of the expanding Commonwealth. Among the new body's preoccupations was the relationship between the medical profession and the state in the associations' respective countries. It thus has to be seen as primarily a medico-political organisation rather than one concerned with medicine per se. Although, there were also tensions from the outset regarding the membership of the Southern African medical associations. Such stresses notwithstanding, these two organisations remained in the BMA-sponsored body even after South Africa and Rhodesia had left the Commonwealth. This was not, however, a situation which could outlast the growing number of African associations which joined in the wake of decolonisation; and hardening attitudes towards apartheid. The article therefore considers: why the BMA set up this Commonwealth body in the first place and what it hoped to achieve; the history of the problems associated with South African and Rhodesian membership; and how their associations came to be expelled.

  4. Plasma devices for hydrocarbon reformation

    KAUST Repository

    Cha, Min

    2017-01-01

    Plasma devices for hydrocarbon reformation are provided. Methods of using the devices for hydrocarbon reformation are also provided. The devices can include a liquid container to receive a hydrocarbon source, and a plasma torch configured

  5. Single-Cell Biomolecular Analysis of Coral Algal Symbionts Reveals Opposing Metabolic Responses to Heat Stress and Expulsion

    Directory of Open Access Journals (Sweden)

    Katherina Petrou

    2018-03-01

    Full Text Available The success of corals in nutrient poor environments is largely attributed to the symbiosis between the cnidarian host and its intracellular alga. Warm water anomalies have been shown to destabilize this symbiosis, yet detailed analysis of the effect of temperature and expulsion on cell-specific carbon and nutrient allocation in the symbiont is limited. Here, we exposed colonies of the hard coral Acropora millepora to heat stress and using synchrotron-based infrared microspectroscopy measured the biomolecular profiles of individual in hospite and expelled symbiont cells at an acute state of bleaching. Our results showed symbiont metabolic profiles to be remarkably distinct with heat stress and expulsion, where the two effectors elicited opposing metabolic adjustments independent of treatment or cell type. Elevated temperature resulted in biomolecular changes reflecting cellular stress, with relative increases in free amino acids and phosphorylation of molecules and a concomitant decline in protein content, suggesting protein modification and degradation. This contrasted with the metabolic profiles of expelled symbionts, which showed relative decreases in free amino acids and phosphorylated molecules, but increases in proteins and lipids, suggesting expulsion lessens the overall effect of heat stress on the metabolic signature of the algal symbionts. Interestingly, the combined effects of expulsion and thermal stress were additive, reducing the overall shifts in all biomolecules, with the notable exception of the significant accumulation of lipids and saturated fatty acids. This first use of a single-cell metabolomics approach on the coral symbiosis provides novel insight into coral bleaching and emphasizes the importance of a single-cell approach to demark the cell-to-cell variability in the physiology of coral cellular populations.

  6. Take it or leave: a five-year prospective study of workplace bullying and indicators of expulsion in working life.

    Science.gov (United States)

    Glambek, Mats; Skogstad, Anders; Einarsen, Ståle

    2015-01-01

    Workplace bullying is often held as a precursor of expulsion in working life, but the claim builds on sparse empirical groundwork. In the present study, bullying is investigated as an antecedent to indicators of expulsion, be it from the workplace (change of employer) or from working life itself (disability benefit recipiency and unemployment), using a nationally representative sample (n=1,613), a five-year time-lag as well as two separate measures of workplace bullying. In line with the hypotheses, logistic regression analyses revealed that both exposure to bullying behaviors and self-labeled bullying are significantly associated with change of employer (OR=1.77 and 2.42, respectively) and disability benefit recipiency (OR=2.81 and 2.95, respectively). Moreover, exposure to bullying behaviors was found to be significantly related to unemployment five years on (OR=4.6). For the self-labeling measure of bullying, this tendency only held true at the 0.1 significance level (OR=3.69, p=0.098). Together, the present results indicate that targets of bullying are at a greater risk of expulsion, both from the workplace and from working life itself, thus representing strong incentives to combat bullying both from the perspective of the individual, the organization and society at large.

  7. Take it or leave: a five-year prospective study of workplace bullying and indicators of expulsion in working life

    Science.gov (United States)

    GLAMBEK, Mats; SKOGSTAD, Anders; EINARSEN, Ståle

    2014-01-01

    Workplace bullying is often held as a precursor of expulsion in working life, but the claim builds on sparse empirical groundwork. In the present study, bullying is investigated as an antecedent to indicators of expulsion, be it from the workplace (change of employer) or from working life itself (disability benefit recipiency and unemployment), using a nationally representative sample (n=1,613), a five-year time-lag as well as two separate measures of workplace bullying. In line with the hypotheses, logistic regression analyses revealed that both exposure to bullying behaviors and self-labeled bullying are significantly associated with change of employer (OR=1.77 and 2.42, respectively) and disability benefit recipiency (OR=2.81 and 2.95, respectively). Moreover, exposure to bullying behaviors was found to be significantly related to unemployment five years on (OR=4.6). For the self-labeling measure of bullying, this tendency only held true at the 0.1 significance level (OR=3.69, p=0.098). Together, the present results indicate that targets of bullying are at a greater risk of expulsion, both from the workplace and from working life itself, thus representing strong incentives to combat bullying both from the perspective of the individual, the organization and society at large. PMID:25475094

  8. Neogene magmatism and its possible causal relationship with hydrocarbon generation in SW Colombia

    Science.gov (United States)

    Vásquez, Mónica; Altenberger, Uwe; Romer, Rolf L.

    2009-07-01

    The Cretaceous oil-bearing source and reservoir sedimentary succession in the Putumayo Basin, SW Colombia, was intruded by gabbroic dykes and sills. The petrological and geochemical character of the magmatic rocks shows calc-alkaline tendency, pointing to a subduction-related magmatic event. K/Ar dating of amphibole indicates a Late Miocene to Pliocene age (6.1 ± 0.7 Ma) for the igneous episode in the basin. Therefore, we assume the intrusions to be part of the Andean magmatism of the Northern Volcanic Zone (NVZ). The age of the intrusions has significant tectonic and economic implications because it coincides with two regional events: (1) the late Miocene/Pliocene Andean orogenic uplift of most of the sub-Andean regions in Peru, Ecuador and Colombia and (2) a pulse of hydrocarbon generation and expulsion that has reached the gas window. High La/Yb, K/Nb and La/Nb ratios, and the obtained Sr-Nd-Pb isotopic compositions suggest the involvement of subducted sediments and/or the assimilation of oceanic crust of the subducting slab. We discuss the possibility that magma chamber(s) west of the basin, below the Cordillera, did increase the heat flow in the basin causing generation and expulsion of hydrocarbons and CO2.

  9. Plasma devices for hydrocarbon reformation

    KAUST Repository

    Cha, Min Suk

    2017-02-16

    Plasma devices for hydrocarbon reformation are provided. Methods of using the devices for hydrocarbon reformation are also provided. The devices can include a liquid container to receive a hydrocarbon source, and a plasma torch configured to be submerged in the liquid. The plasma plume from the plasma torch can cause reformation of the hydrocarbon. The device can use a variety of plasma torches that can be arranged in a variety of positions in the liquid container. The devices can be used for the reformation of gaseous hydrocarbons and/or liquid hydrocarbons. The reformation can produce methane, lower hydrocarbons, higher hydrocarbons, hydrogen gas, water, carbon dioxide, carbon monoxide, or a combination thereof.

  10. Study of the direct detection of crosslinking in hydrocarbons by 13C-NMR. II. Identification of crosslink in model compound and application to irradiate paraffins

    International Nuclear Information System (INIS)

    Bennett, R.L.; Keller, A.; Stejny, H.H.; Murray, M.

    1976-01-01

    A 13 C-NMR investigation was carried out in aid of direct detection of crosslinks in hydrocarbons with the future objective of studying radiation-induced crosslinking in polyethylene by a direct method. The resonance signal due to a tertiary carbon atom appropriate to a crosslink far remote from molecular ends has been identified in a definitive manner with the aid of the H-shaped model compound 1,1,2,2-tetra(tridecyl)ethane synthetized in Part I of this study. This identification was then put to use in the examination of the irradiated linear paraffins n-hexadecane and n-eicosane, where it enabled the detection of radiation-induced crosslinks. This crosslinking could then be associated with corresponding changes in molecular weight (dimer, trimer formation) as revealed by discrete peaks in the gel-permeation chromatograms of the same samples and randomness of the crosslinking process in the liquid state of these compounds being inferred

  11. Quantitative structure-activity relationship (QSAR) models for polycyclic aromatic hydrocarbons (PAHs) dissipation in rhizosphere based on molecular structure and effect size

    International Nuclear Information System (INIS)

    Ma Bin; Chen Huaihai; Xu Minmin; Hayat, Tahir; He Yan; Xu Jianming

    2010-01-01

    Rhizoremediation is a significant form of bioremediation for polycyclic aromatic hydrocarbons (PAHs). This study examined the role of molecular structure in determining the rhizosphere effect on PAHs dissipation. Effect size in meta-analysis was employed as activity dataset for building quantitative structure-activity relationship (QSAR) models and accumulative effect sizes of 16 PAHs were used for validation of these models. Based on the genetic algorithm combined with partial least square regression, models for comprehensive dataset, Poaceae dataset, and Fabaceae dataset were built. The results showed that information indices, calculated as information content of molecules based on the calculation of equivalence classes from the molecular graph, were the most important molecular structural indices for QSAR models of rhizosphere effect on PAHs dissipation. The QSAR model, based on the molecular structure indices and effect size, has potential to be used in studying and predicting the rhizosphere effect of PAHs dissipation. - Effect size based on meta-analysis was used for building PAHs dissipation quantitative structure-activity relationship (QSAR) models.

  12. Quantitative structure-activity relationship (QSAR) models for polycyclic aromatic hydrocarbons (PAHs) dissipation in rhizosphere based on molecular structure and effect size

    Energy Technology Data Exchange (ETDEWEB)

    Ma Bin; Chen Huaihai; Xu Minmin; Hayat, Tahir [Zhejiang Provincial Key Laboratory of Subtropical Soil and Plant Nutrition, College of Environmental and Natural Resource Sciences, Zhejiang University, Hangzhou 310029 (China); He Yan, E-mail: yhe2006@zju.edu.c [Zhejiang Provincial Key Laboratory of Subtropical Soil and Plant Nutrition, College of Environmental and Natural Resource Sciences, Zhejiang University, Hangzhou 310029 (China); Xu Jianming, E-mail: jmxu@zju.edu.c [Zhejiang Provincial Key Laboratory of Subtropical Soil and Plant Nutrition, College of Environmental and Natural Resource Sciences, Zhejiang University, Hangzhou 310029 (China)

    2010-08-15

    Rhizoremediation is a significant form of bioremediation for polycyclic aromatic hydrocarbons (PAHs). This study examined the role of molecular structure in determining the rhizosphere effect on PAHs dissipation. Effect size in meta-analysis was employed as activity dataset for building quantitative structure-activity relationship (QSAR) models and accumulative effect sizes of 16 PAHs were used for validation of these models. Based on the genetic algorithm combined with partial least square regression, models for comprehensive dataset, Poaceae dataset, and Fabaceae dataset were built. The results showed that information indices, calculated as information content of molecules based on the calculation of equivalence classes from the molecular graph, were the most important molecular structural indices for QSAR models of rhizosphere effect on PAHs dissipation. The QSAR model, based on the molecular structure indices and effect size, has potential to be used in studying and predicting the rhizosphere effect of PAHs dissipation. - Effect size based on meta-analysis was used for building PAHs dissipation quantitative structure-activity relationship (QSAR) models.

  13. Interactive chemistry in the Laboratoire de Météorologie Dynamique general circulation model: model description and impact analysis of biogenic hydrocarbons on tropospheric chemistry

    Directory of Open Access Journals (Sweden)

    G. A. Folberth

    2006-01-01

    Full Text Available We present a description and evaluation of LMDz-INCA, a global three-dimensional chemistry-climate model, pertaining to its recently developed NMHC version. In this substantially extended version of the model a comprehensive representation of the photochemistry of non-methane hydrocarbons (NMHC and volatile organic compounds (VOC from biogenic, anthropogenic, and biomass-burning sources has been included. The tropospheric annual mean methane (9.2 years and methylchloroform (5.5 years chemical lifetimes are well within the range of previous modelling studies and are in excellent agreement with estimates established by means of global observations. The model provides a reasonable simulation of the horizontal and vertical distribution and seasonal cycle of CO and key non-methane VOC, such as acetone, methanol, and formaldehyde as compared to observational data from several ground stations and aircraft campaigns. LMDz-INCA in the NMHC version reproduces tropospheric ozone concentrations fairly well throughout most of the troposphere. The model is applied in several sensitivity studies of the biosphere-atmosphere photochemical feedback. The impact of surface emissions of isoprene, acetone, and methanol is studied. These experiments show a substantial impact of isoprene on tropospheric ozone and carbon monoxide concentrations revealing an increase in surface O3 and CO levels of up to 30 ppbv and 60 ppbv, respectively. Isoprene also appears to significantly impact the global OH distribution resulting in a decrease of the global mean tropospheric OH concentration by approximately 0.7×105 molecules cm-3 or roughly 8% and an increase in the global mean tropospheric methane lifetime by approximately seven months. A global mean ozone net radiative forcing due to the isoprene induced increase in the tropospheric ozone burden of 0.09 W m-2 is found. The key role of isoprene photooxidation in the global tropospheric redistribution of NOx is demonstrated. LMDz

  14. Efficacy and Safety of Alfuzosin as Medical Expulsive Therapy for Ureteral Stones: A Systematic Review and Meta-Analysis.

    Directory of Open Access Journals (Sweden)

    Chenli Liu

    Full Text Available Alfuzosin has been widely used to treat benign prostatic hyperplasia and prostatitis, and is claimed to be a selective agent for the lower urinary tract with low incidence of adverse side-effects and hypotensive changes. Recently, several randomized controlled trials have reported using Alfuzosin as an expulsive therapy of ureteral stones. Tamsulosin, another alpha blocker, has also been used as an agent for the expulsive therapy for ureteral stones. It is unclear whether alfuzosin has similar efficacy as Tamsulosin in the management of ureteral stones.To perform a systematic review and analysis of literatures comparing Alfuzosin with Tamsulosin or standard conservative therapy for the treatment of ureteral stones less than 10 mm in diameter.A systematic literature review was performed in December 2014 using Pubmed, Embase, and the Cochrane library databases to identify relevant studies. All randomized and controlled trials were included. A subgroup analysis was performed comparing Alfuzosin with control therapy on the management of distal ureteral stones.Alfuzosin provided a significantly higher stone-free rate than the control treatments (RR: 1.85; 95% confidence interval [CI], 1.35-2.55; p<0.001, and a shorter stone expulsion time (Weighted mean difference [WMD]: -4.20 d, 95%CI, -6.19 to -2.21; p<0.001, but it has a higher complication rate (RR: 2.02; 95% CI, 1.30-3.15; p<0.01. When Alfuzosin was compared to Tamsulosin, there was no significant difference in terms of stone-free rate (RR: 0.90; 95% CI, 0.79-1.02; p = 0.09 as well as the stone expulsion time (WMD: 0.52 d, 95%CI, -1.61 to 2.64; p = 0.63. The adverse effects of Alfuzosin were similar to those of Tamsulosin (RR: 0.88; 95% CI, 0.61-1.26; p = 0.47.Alfuzosin is a safe and effective agent for the expulsive therapy of ureteral stones smaller than 10 mm in size. It is more effective than therapeutic regiment without alpha blocker. It is equivalent to Tamsulosin in its effectiveness and

  15. Induction of a chloracne phenotype in an epidermal equivalent model by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is dependent on aryl hydrocarbon receptor activation and is not reproduced by aryl hydrocarbon receptor knock down.

    Science.gov (United States)

    Forrester, Alison R; Elias, Martina S; Woodward, Emma L; Graham, Mark; Williams, Faith M; Reynolds, Nick J

    2014-01-01

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a potent activator of the aryl hydrocarbon receptor (AhR) and causes chloracne in humans. The pathogenesis and role of AhR in chloracne remains incompletely understood. To elucidate the mechanisms contributing to the development of the chloracne-like phenotype in a human epidermal equivalent model and identify potential biomarkers. Using primary normal human epidermal keratinocytes (NHEK), we studied AhR activation by XRE-luciferase, AhR degradation and CYP1A1 induction. We treated epidermal equivalents with high affinity TCDD or two non-chloracnegens: β-naphthoflavone (β-NF) and 2-(1'H-indole-3'-carbonyl)-thiazole-4-carboxylic acid methyl ester (ITE). Using Western blotting and immunochemistry for filaggrin (FLG), involucrin (INV) and transglutaminase-1 (TGM-1), we compared the effects of the ligands on keratinocyte differentiation and development of the chloracne-like phenotype by H&E. In NHEKs, activation of an XRE-luciferase and CYP1A1 protein induction correlated with ligand binding affinity: TCDD>β-NF>ITE. AhR degradation was induced by all ligands. In epidermal equivalents, TCDD induced a chloracne-like phenotype, whereas β-NF or ITE did not. All three ligands induced involucrin and TGM-1 protein expression in epidermal equivalents whereas FLG protein expression decreased following treatment with TCDD and β-NF. Inhibition of AhR by α-NF blocked TCDD-induced AhR activation in NHEKs and blocked phenotypic changes in epidermal equivalents; however, AhR knock down did not reproduce the phenotype. Ligand-induced CYP1A1 and AhR degradation did not correlate with their chloracnegenic potential, indicating that neither CYP1A1 nor AhR are suitable biomarkers. Mechanistic studies showed that the TCDD-induced chloracne-like phenotype depends on AhR activation whereas AhR knock down did not appear sufficient to induce the phenotype. Copyright © 2013 Japanese Society for Investigative Dermatology. Published by Elsevier

  16. Physical and chemical comparison of soot in hydrocarbon and biodiesel fuel diffusion flames: A study of model and commercial fuels

    Energy Technology Data Exchange (ETDEWEB)

    Matti Maricq, M. [Research and Advanced Engineering, Ford Motor Company, Dearborn, MI (United States)

    2011-01-15

    Data are presented to compare soot formation in both surrogate and practical fatty acid methyl ester biodiesel and petroleum fuel diffusion flames. The approach here uses differential mobility analysis to follow the size distributions and electrical charge of soot particles as they evolve in the flame, and laser ablation particle mass spectrometry to elucidate their composition. Qualitatively, these soot properties exhibit a remarkably similar development along the flames. The size distributions begin as a single mode of precursor nanoparticles, evolve through a bimodal phase marking the onset of aggregate formation, and end in a self preserving mode of fractal-like particles. Both biodiesel and hydrocarbon fuels yield a common soot composition dominated by C{sub x}H{sub y}{sup +} ions, stabilomer PAHs, and fullerenes in the positive ion mass spectrum, and C{sub x}{sup -} and C{sub 2x}H{sup -} in the negative ion spectrum. These ion intensities initially grow with height in the diffusion flames, but then decline during later stages, consistent with soot carbonization. There are important quantitative differences between fuels. The surrogate biodiesel fuel methyl butanoate substantially reduces soot levels, but soot formation and evolution in this flame are delayed relative to both soy and petroleum fuels. In contrast, soots from soy and hexadecane flames exhibit nearly quantitative agreement in their size distribution and composition profiles with height, suggesting similar soot precursor chemistry. (author)

  17. Method for the conversion of hydrocarbon charges

    Energy Technology Data Exchange (ETDEWEB)

    Whittam, T V

    1976-11-11

    The basis of the invention is the application of defined zeolites as catalysts to hydrocarbon conversion processes such as reformation, isomerization, dehydrocyclization, and cracking. By charging the zeolite carrier masses with 0.001 to 5% metal of the 8th group of the periodic system, preferably noble metals, a wide region of applications for the catalysts is achieved. A method for the isomerization of an alkyl benzene (or mixture of alkyl benzenes) in the liquid or gas phase under suitable temperature, pressure and flow-rate conditions, as well as in the presence of a cyclic hydrocarbon, is described as preferential model form of the invention; furthermore, a method for the reformation of a hydrocarbon fraction boiling in the gasoline or benzene boiling region and a method for the hydrocracking of hydrocarbon charge (e.g. naphtha, kerosine, gas oils) are given. Types of performance of the methods are explained using various examples.

  18. Comparative experimental and modeling studies of the viscosity behavior of ethanol+C7 hydrocarbon mixtures versus pressure and temperature

    DEFF Research Database (Denmark)

    Zeberg-Mikkelsen, Claus Kjær; Watson, G.; Baylaucq, A.

    2006-01-01

    viscosity models with a physical and theoretical background. The evaluated models are based on the hard-sphere scheme, the concepts of the free-volume and the friction theory, and a model derived from molecular dynamics. In addition to these models, the simple compositional models by Grunberg-Nissan...

  19. Thraustochytrid protists degrade hydrocarbons

    Digital Repository Service at National Institute of Oceanography (India)

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

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

  20. Purifying hydrocarbon oils

    Energy Technology Data Exchange (ETDEWEB)

    Rostin, H

    1938-08-11

    A process is described for continuously purifying hydrocarbon oils consisting in conducting the vapors of the same at a temperature of 300 to 400/sup 0/C over the oelitic ore minette together with reducing gases in presence of steam the proportion of the reducing gases and steam being such that the sulfur of the hydrocarbons escapes from the reaction chamber in the form of sulfuretted hydrogen without permanent sulfide of iron being formed.

  1. Process for refining hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Risenfeld, E H

    1924-11-26

    A process is disclosed for the refining of hydrocarbons or other mixtures through treatment in vapor form with metal catalysts, characterized by such metals being used as catalysts, which are obtained by reduction of the oxide of minerals containing the iron group, and by the vapors of the hydrocarbons, in the presence of the water vapor, being led over these catalysts at temperatures from 200 to 300/sup 0/C.

  2. Efficacy and Safety of Tamsulosin in Medical Expulsive Therapy for Distal Ureteral Stones with Renal Colic: A Multicenter, Randomized, Double-blind, Placebo-controlled Trial.

    Science.gov (United States)

    Ye, Zhangqun; Zeng, Guohua; Yang, Huan; Tang, Kun; Zhang, Xiaochun; Li, Hong; Li, Weibing; Wu, Zhong; Chen, Lingwu; Chen, Xingfa; Liu, Xiankui; Deng, Yaoliang; Pan, Tiejun; Xing, Jinchun; Wang, Shusheng; Cheng, Yue; Gu, Xiaojian; Gao, Wenxi; Yang, Jianggen; Zhang, Yonghai; Mi, Qiwu; Qi, Lin; Li, Jiongming; Hu, Weilie; Liang, Peiyu; Sun, Zhaolin; Xu, Changbao; Long, Yongfu; Liao, Yongbin; Liu, Siping; Liu, Guoqing; Xu, Xun; He, Wei; Chen, Zhiqiang; Xu, Hua

    2017-11-12

    Recent large high-quality trials have questioned the clinical effectiveness of medical expulsive therapy using tamsulosin for ureteral stones. To evaluate the efficacy and safety of tamsulosin for distal ureteral stones compared with placebo. We conducted a double-blind, placebo-controlled study of 3296 patients with distal ureteral stones, across 30 centers, to evaluate the efficacy and safety of tamsulosin. Participants were randomly assigned (1:1) into tamsulosin (0.4mg) or placebo groups for 4 wk. The primary end point of analysis was the overall stone expulsion rate, defined as stone expulsion, confirmed by negative findings on computed tomography, over a 28-d surveillance period. Secondary end points included time to stone expulsion, use of analgesics, and incidence of adverse events. Among 3450 patients randomized between September 1, 2011, and August 31, 2013, 3296 (96%) were included in the primary analysis. Tamsulosin benefits from a higher stone expulsion rate than the placebo (86% vs 79%; ptamsulosin for the treatment of large distal ureteral stones (>5mm). Considering the secondary end points, tamsulosin-treated patients reported a shorter time to expulsion (ptamsulosin use benefits distal ureteral stones in facilitating stone passage and relieving renal colic. Subgroup analyses find that tamsulosin provides a superior expulsion rate for stones >5mm, but no effect for stones ≤5mm. In this report, we looked at the efficacy and safety of tamsulosin for the treatment of distal ureteral stones. We find that tamsulosin significantly facilitates the passage of distal ureteral stones and relieves renal colic. Copyright © 2017 European Association of Urology. Published by Elsevier B.V. All rights reserved.

  3. Comparison of atomic-level and coarse-grained models for liquid hydrocarbons from molecular dynamics configurational entropy estimates

    NARCIS (Netherlands)

    Baron, R; de Vries, AH; Hunenberger, PH; van Gunsteren, WF

    2006-01-01

    Molecular liquids can be modeled at different levels of spatial resolution. In atomic-level (AL) models, all (heavy) atoms can be explicitly simulated. In coarse-grained (CG) models, particles (beads) that represent groups of covalently bound atoms are used as elementary units. Ideally, a CG model

  4. Implications and concerns of deep-seated disposal of hydrocarbon exploration produced water using three-dimensional contaminant transport model in Bhit Area, Dadu District of Southern Pakistan.

    Science.gov (United States)

    Ahmad, Zulfiqar; Akhter, Gulraiz; Ashraf, Arshad; Fryar, Alan

    2010-11-01

    A three-dimensional contaminant transport model has been developed to simulate and monitor the migration of disposal of hydrocarbon exploration produced water in Injection well at 2,100 m depth in the Upper Cretaceous Pab sandstone, Bhit area in Dadu district of Southern Pakistan. The regional stratigraphic and structural geological framework of the area, landform characteristics, meteorological parameters, and hydrogeological milieu have been used in the model to generate the initial simulation of steady-state flow condition in the underlying aquifer's layers. The geometry of the shallow and deep-seated characteristics of the geological formations was obtained from the drilling data, electrical resistivity sounding surveys, and geophysical well-logging information. The modeling process comprised of steady-state simulation and transient simulation of the prolific groundwater system of contamination transport after 1, 10, 30 years of injection. The contaminant transport was evaluated from the bottom of the injection well, and its short- and long-term effects were determined on aquifer system lying in varying hydrogeological and geological conditions.

  5. High molecular weight non-polar hydrocarbons as pure model substances and in motor oil samples can be ionized without fragmentation by atmospheric pressure chemical ionization mass spectrometry.

    Science.gov (United States)

    Hourani, Nadim; Kuhnert, Nikolai

    2012-10-15

    High molecular weight non-polar hydrocarbons are still difficult to detect by mass spectrometry. Although several studies have targeted this problem, lack of good self-ionization has limited the ability of mass spectrometry to examine these hydrocarbons. Failure to control ion generation in the atmospheric pressure chemical ionization (APCI) source hampers the detection of intact stable gas-phase ions of non-polar hydrocarbon in mass spectrometry. Seventeen non-volatile non-polar hydrocarbons, reported to be difficult to ionize, were examined by an optimized APCI methodology using nitrogen as the reagent gas. All these analytes were successfully ionized as abundant and intact stable [M-H](+) ions without the use of any derivatization or adduct chemistry and without significant fragmentation. Application of the method to real-life hydrocarbon mixtures like light shredder waste and car motor oil was demonstrated. Despite numerous reports to the contrary, it is possible to ionize high molecular weight non-polar hydrocarbons by APCI, omitting the use of additives. This finding represents a significant step towards extending the applicability of mass spectrometry to non-polar hydrocarbon analyses in crude oil, petrochemical products, waste or food. Copyright © 2012 John Wiley & Sons, Ltd.

  6. Electrostatically atomised hydrocarbon sprays

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-07-01

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

  7. The Use of Medical Expulsive Therapy During Pregnancy: A Worldwide Perspective Among Experts.

    Science.gov (United States)

    Lloyd, Granville L; Lim, Amy; Hamoui, Nabeel; Nakada, Stephen Y; Kielb, Stephanie J

    2016-03-01

    Medical expulsive therapy (MET) is a pharmacologic approach thought to augment the spontaneous passage of ureteral calculi. The usage of MET pharmacologics for presumed ureteral calculi during pregnancy has not been studied and their safety and utility are unknown. We sought to characterize the worldwide usage of MET in the setting of pregnancy with presumed ureteral calculus (P-MET), as well as factors associated with physician use. Experts in stone management were specifically sought. A nine-question survey was delivered through society-administered e-mail. Questions gathered physician's worldwide region, degree of specialization in stone disease, practice type, interval since training, and willingness to use both MET and P-MET. We assessed drugs of choice in those using P-MET and reasons for avoidance in non-P-MET users. Finally, we assessed the impact of physician-perceived medicolegal risk on usage of P-MET. Five hundred sixty-five responses were recorded. Sixty-three percent were US-based practitioners and the remaining represented a worldwide distribution. Worldwide usage of MET was 97.6%, and tamsulosin was globally preferred by over 90% of urologists. P-MET was endorsed by only 44.3%. 23.6% of European practitioners used this strategy compared with 51.1% of US physicians. Time from training and practice type did not significantly interact with adoption of P-MET; experts were less likely to use P-MET. Physician nonuse of MET during pregnancy was adverse outcome related: 76.7% reported either the fear of legal risk (52.8%) or concerns about safety (23.9%). Respondents report impressive worldwide adoption of MET. P-MET is less trusted, and fears of legal risk and safety far outweigh questions about effectiveness. The effectiveness of drugs during pregnancy-induced ureteral dilation is unknown. Still, 44% of global respondents embrace usage of this drug strategy despite a paucity of evidence supporting either safety or effectiveness during pregnancy.

  8. Use of medical expulsive therapy in children: An assessment of nationwide practice patterns and outcomes

    Science.gov (United States)

    Ellison, Jonathan S.; Merguerian, Paul A.; Fu, Benjamin C.; Holt, Sarah K.; Lendvay, Thomas S.; Gore, John L.; Shnorhavorian, Margarett

    2018-01-01

    Summary Introduction Early data support the use of medical expulsive therapy (MET) in children. However, little is known regarding use or outcomes associated with MET outside of pediatric-specific practices. Using a national administrative dataset, we sought to characterize utilization patterns of MET as well as assess outcomes associated with MET exposure. Study design We interrogated the MarketScan Commercial Claims and Encounters database to identify children under the age of 18 presenting to the emergency department (ED) with any diagnosis of upper urinary tract calculi (UUTC, including renal and ureteral calculi). MET exposure was defined as having a prescription filled for a MET agent within 1 week of the ED encounter. Characteristics of children receiving MET were defined and outcomes compared between children with and without MET exposure. Results Of 1325 children included in the study, 13.2% received MET, including 15.4% of children with a diagnosis of “calculus of the ureter.” MET use increased significantly throughout the study period (p = 0.004), although only 30.4% of children considered potential MET candidates received MET in the final year of the study (2013). Among all patients, receipt of MET was associated with male gender, presence of comorbidity, provider-type (urologist), and year of diagnosis, although among those with a specific diagnosis of “calculus of the ureter,” only year of diagnosis remained a significant factor. Rates of unplanned physician visits and surgical interventions were similar between groups. Children receiving MET were more likely to receive follow-up imaging, although only 46% of children with ureteral calculi had appropriate follow-up imaging within 90 days, regardless of MET exposure. Odds ratios of factors and outcomes associated with MET exposure are shown in the Table. Discussion Although early data support safety and efficacy MET in children, nationwide use in children is low among potential candidates for

  9. Calculating the number of shock waves, expulsion time, and optimum stone parameters based on noncontrast computerized tomography characteristics.

    Science.gov (United States)

    Foda, Khaled; Abdeldaeim, Hussein; Youssif, Mohamed; Assem, Akram

    2013-11-01

    To define the parameters that accompanied a successful extracorporeal shock wave lithotripsy (ESWL), namely the number of shock waves (SWs), expulsion time (ET), mean stone density (MSD), and the skin-to-stone distance (SSD). A total of 368 patients diagnosed with renal calculi using noncontrast computerized tomography had their MSD, diameter, and SSD recorded. All patients were treated using a Siemens lithotripter. ESWL success meant a stone-free status or presence of residual fragments 934 HUs and SSD >99 mm. The required number of SWs and the expected ET can be anticipated. Copyright © 2013 Elsevier Inc. All rights reserved.

  10. Assessing impediments to hydrocarbon biodegradation in weathered contaminated soils.

    Science.gov (United States)

    Adetutu, Eric; Weber, John; Aleer, Sam; Dandie, Catherine E; Aburto-Medina, Arturo; Ball, Andrew S; Juhasz, Albert L

    2013-10-15

    In this study, impediments to hydrocarbon biodegradation in contaminated soils were assessed using chemical and molecular methodologies. Two long-term hydrocarbon contaminated soils were utilised which were similar in physico-chemical properties but differed in the extent of hydrocarbon (C10-C40) contamination (S1: 16.5 g kg(-1); S2: 68.9 g kg(-1)). Under enhanced natural attenuation (ENA) conditions, hydrocarbon biodegradation was observed in S1 microcosms (26.4% reduction in C10-C40 hydrocarbons), however, ENA was unable to stimulate degradation in S2. Although eubacterial communities (PCR-DGGE analysis) were similar for both soils, the alkB bacterial community was less diverse in S2 presumably due to impacts associated with elevated hydrocarbons. When hydrocarbon bioaccessibility was assessed using HP-β-CD extraction, large residual concentrations remained in the soil following the extraction procedure. However, when linear regression models were used to predict the endpoints of hydrocarbon degradation, there was no significant difference (P>0.05) between HP-β-CD predicted and microcosm measured biodegradation endpoints. This data suggested that the lack of hydrocarbon degradation in S2 resulted primarily from limited hydrocarbon bioavailability. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. Thermodynamics of organic mixtures containing amines. X. Phase equilibria for binary systems formed by imidazoles and hydrocarbons: Experimental data and modelling using DISQUAC

    Energy Technology Data Exchange (ETDEWEB)

    Domanska, Urszula; Zawadzki, Maciej [Physical Chemistry Division, Faculty of Chemistry, Warsaw University of Technology, 00-664 Warsaw (Poland); Gonzalez, Juan Antonio, E-mail: jagl@termo.uva.e [G.E.T.E.F., Grupo Especializado en Termodinamica de Equilibrio entre Fases, Departamento de Fisica Aplicada, Facultad de Ciencias, Universidad de Valladolid, E-47071, Valladolid (Spain)

    2010-04-15

    (Solid + liquid) equilibrium (SLE) temperatures have been determined using a dynamic method for the systems (1H-imidazole, + benzene, + toluene, + hexane, or + cyclohexane; 1-methylimidazole + benzene, or + toluene, 2-methyl-1H-imidazole + benzene, + toluene, or + cyclohexane, and benzimidazole + benzene). In addition (liquid + liquid) equilibrium (LLE) temperatures have been obtained using a cloud point method for (1H-imidazole, + hexane, or + cyclohexane; 1-methylimidazole + toluene, and 2-methyl-1H-imidazole + cyclohexane). The measured systems show positive deviations from the Raoult's law, due to strong dipolar interactions between amine molecules related to the high dipole moment of imidazoles. On the other hand, DISQUAC interaction parameters for the contacts present in these solutions and for the amine/hydroxyl contacts in (1H-imidazole + 1-alkanol) mixtures have been determined. The model correctly represents the available data for the examined systems. Deviations between experimental and calculated SLE temperatures are similar to those obtained using the Wilson or NRTL equations, or the UNIQUAC association solution model. The quasichemical interaction parameters are the same for mixtures containing 1H-imidazole, 1-methylimidazole, or 2-methyl-1H-imidazole and hydrocarbons. This may be interpreted assuming that they are members of a homologous series. Benzimidazole behaves differently.

  12. Analysis of intervention strategies for inhalation exposure to polycyclic aromatic hydrocarbons and associated lung cancer risk based on a Monte Carlo population exposure assessment model.

    Science.gov (United States)

    Zhou, Bin; Zhao, Bin

    2014-01-01

    It is difficult to evaluate and compare interventions for reducing exposure to air pollutants, including polycyclic aromatic hydrocarbons (PAHs), a widely found air pollutant in both indoor and outdoor air. This study presents the first application of the Monte Carlo population exposure assessment model to quantify the effects of different intervention strategies on inhalation exposure to PAHs and the associated lung cancer risk. The method was applied to the population in Beijing, China, in the year 2006. Several intervention strategies were designed and studied, including atmospheric cleaning, smoking prohibition indoors, use of clean fuel for cooking, enhancing ventilation while cooking and use of indoor cleaners. Their performances were quantified by population attributable fraction (PAF) and potential impact fraction (PIF) of lung cancer risk, and the changes in indoor PAH concentrations and annual inhalation doses were also calculated and compared. The results showed that atmospheric cleaning and use of indoor cleaners were the two most effective interventions. The sensitivity analysis showed that several input parameters had major influence on the modeled PAH inhalation exposure and the rankings of different interventions. The ranking was reasonably robust for the remaining majority of parameters. The method itself can be extended to other pollutants and in different places. It enables the quantitative comparison of different intervention strategies and would benefit intervention design and relevant policy making.

  13. Analysis of intervention strategies for inhalation exposure to polycyclic aromatic hydrocarbons and associated lung cancer risk based on a Monte Carlo population exposure assessment model.

    Directory of Open Access Journals (Sweden)

    Bin Zhou

    Full Text Available It is difficult to evaluate and compare interventions for reducing exposure to air pollutants, including polycyclic aromatic hydrocarbons (PAHs, a widely found air pollutant in both indoor and outdoor air. This study presents the first application of the Monte Carlo population exposure assessment model to quantify the effects of different intervention strategies on inhalation exposure to PAHs and the associated lung cancer risk. The method was applied to the population in Beijing, China, in the year 2006. Several intervention strategies were designed and studied, including atmospheric cleaning, smoking prohibition indoors, use of clean fuel for cooking, enhancing ventilation while cooking and use of indoor cleaners. Their performances were quantified by population attributable fraction (PAF and potential impact fraction (PIF of lung cancer risk, and the changes in indoor PAH concentrations and annual inhalation doses were also calculated and compared. The results showed that atmospheric cleaning and use of indoor cleaners were the two most effective interventions. The sensitivity analysis showed that several input parameters had major influence on the modeled PAH inhalation exposure and the rankings of different interventions. The ranking was reasonably robust for the remaining majority of parameters. The method itself can be extended to other pollutants and in different places. It enables the quantitative comparison of different intervention strategies and would benefit intervention design and relevant policy making.

  14. Thermodynamics of organic mixtures containing amines. X. Phase equilibria for binary systems formed by imidazoles and hydrocarbons: Experimental data and modelling using DISQUAC

    International Nuclear Information System (INIS)

    Domanska, Urszula; Zawadzki, Maciej; Gonzalez, Juan Antonio

    2010-01-01

    (Solid + liquid) equilibrium (SLE) temperatures have been determined using a dynamic method for the systems (1H-imidazole, + benzene, + toluene, + hexane, or + cyclohexane; 1-methylimidazole + benzene, or + toluene, 2-methyl-1H-imidazole + benzene, + toluene, or + cyclohexane, and benzimidazole + benzene). In addition (liquid + liquid) equilibrium (LLE) temperatures have been obtained using a cloud point method for (1H-imidazole, + hexane, or + cyclohexane; 1-methylimidazole + toluene, and 2-methyl-1H-imidazole + cyclohexane). The measured systems show positive deviations from the Raoult's law, due to strong dipolar interactions between amine molecules related to the high dipole moment of imidazoles. On the other hand, DISQUAC interaction parameters for the contacts present in these solutions and for the amine/hydroxyl contacts in (1H-imidazole + 1-alkanol) mixtures have been determined. The model correctly represents the available data for the examined systems. Deviations between experimental and calculated SLE temperatures are similar to those obtained using the Wilson or NRTL equations, or the UNIQUAC association solution model. The quasichemical interaction parameters are the same for mixtures containing 1H-imidazole, 1-methylimidazole, or 2-methyl-1H-imidazole and hydrocarbons. This may be interpreted assuming that they are members of a homologous series. Benzimidazole behaves differently.

  15. Numerical simulation of in-situ chemical oxidation (ISCO) and biodegradation of petroleum hydrocarbons using a coupled model for bio-geochemical reactive transport

    Science.gov (United States)

    Marin, I. S.; Molson, J. W.

    2013-05-01

    Petroleum hydrocarbons (PHCs) are a major source of groundwater contamination, being a worldwide and well-known problem. Formed by a complex mixture of hundreds of organic compounds (including BTEX - benzene, toluene, ethylbenzene and xylenes), many of which are toxic and persistent in the subsurface and are capable of creating a serious risk to human health. Several remediation technologies can be used to clean-up PHC contamination. In-situ chemical oxidation (ISCO) and intrinsic bioremediation (IBR) are two promising techniques that can be applied in this case. However, the interaction of these processes with the background aquifer geochemistry and the design of an efficient treatment presents a challenge. Here we show the development and application of BIONAPL/Phreeqc, a modeling tool capable of simulating groundwater flow, contaminant transport with coupled biological and geochemical processes in porous or fractured porous media. BIONAPL/Phreeqc is based on the well-tested BIONAPL/3D model, using a powerful finite element simulation engine, capable of simulating non-aqueous phase liquid (NAPL) dissolution, density-dependent advective-dispersive transport, and solving the geochemical and kinetic processes with the library Phreeqc. To validate the model, we compared BIONAPL/Phreeqc with results from the literature for different biodegradation processes and different geometries, with good agreement. We then used the model to simulate the behavior of sodium persulfate (NaS2O8) as an oxidant for BTEX degradation, coupled with sequential biodegradation in a 2D case and to evaluate the effect of inorganic geochemistry reactions. The results show the advantages of a treatment train remediation scheme based on ISCO and IBR. The numerical performance and stability of the integrated BIONAPL/Phreeqc model was also verified.

  16. Hydrocarbon Reserves: Abundance or Scarcity

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    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)

  17. Hydrocarbon Reserves: Abundance or Scarcity

    International Nuclear Information System (INIS)

    2005-01-01

    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)

  18. Hydrocarbon Reserves: Abundance or Scarcity

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    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)

  19. Sub-basalt Imaging of Hydrocarbon-Bearing Mesozoic Sediments Using Ray-Trace Inversion of First-Arrival Seismic Data and Elastic Finite-Difference Full-Wave Modeling Along Sinor-Valod Profile of Deccan Syneclise, India

    Science.gov (United States)

    Talukdar, Karabi; Behera, Laxmidhar

    2018-03-01

    Imaging below the basalt for hydrocarbon exploration is a global problem because of poor penetration and significant loss of seismic energy due to scattering, attenuation, absorption and mode-conversion when the seismic waves encounter a highly heterogeneous and rugose basalt layer. The conventional (short offset) seismic data acquisition, processing and modeling techniques adopted by the oil industry generally fails to image hydrocarbon-bearing sub-trappean Mesozoic sediments hidden below the basalt and is considered as a serious problem for hydrocarbon exploration in the world. To overcome this difficulty of sub-basalt imaging, we have generated dense synthetic seismic data with the help of elastic finite-difference full-wave modeling using staggered-grid scheme for the model derived from ray-trace inversion using sparse wide-angle seismic data acquired along Sinor-Valod profile in the Deccan Volcanic Province of India. The full-wave synthetic seismic data generated have been processed and imaged using conventional seismic data processing technique with Kirchhoff pre-stack time and depth migrations. The seismic image obtained correlates with all the structural features of the model obtained through ray-trace inversion of wide-angle seismic data, validating the effectiveness of robust elastic finite-difference full-wave modeling approach for imaging below thick basalts. Using the full-wave modeling also allows us to decipher small-scale heterogeneities imposed in the model as a measure of the rugose basalt interfaces, which could not be dealt with ray-trace inversion. Furthermore, we were able to accurately image thin low-velocity hydrocarbon-bearing Mesozoic sediments sandwiched between and hidden below two thick sequences of high-velocity basalt layers lying above the basement.

  20. Source apportionment of ambient non-methane hydrocarbons in Hong Kong: application of a principal component analysis/absolute principal component scores (PCA/APCS) receptor model.

    Science.gov (United States)

    Guo, H; Wang, T; Louie, P K K

    2004-06-01

    Receptor-oriented source apportionment models are often used to identify sources of ambient air pollutants and to estimate source contributions to air pollutant concentrations. In this study, a PCA/APCS model was applied to the data on non-methane hydrocarbons (NMHCs) measured from January to December 2001 at two sampling sites: Tsuen Wan (TW) and Central & Western (CW) Toxic Air Pollutants Monitoring Stations in Hong Kong. This multivariate method enables the identification of major air pollution sources along with the quantitative apportionment of each source to pollutant species. The PCA analysis identified four major pollution sources at TW site and five major sources at CW site. The extracted pollution sources included vehicular internal engine combustion with unburned fuel emissions, use of solvent particularly paints, liquefied petroleum gas (LPG) or natural gas leakage, and industrial, commercial and domestic sources such as solvents, decoration, fuel combustion, chemical factories and power plants. The results of APCS receptor model indicated that 39% and 48% of the total NMHCs mass concentrations measured at CW and TW were originated from vehicle emissions, respectively. 32% and 36.4% of the total NMHCs were emitted from the use of solvent and 11% and 19.4% were apportioned to the LPG or natural gas leakage, respectively. 5.2% and 9% of the total NMHCs mass concentrations were attributed to other industrial, commercial and domestic sources, respectively. It was also found that vehicle emissions and LPG or natural gas leakage were the main sources of C(3)-C(5) alkanes and C(3)-C(5) alkenes while aromatics were predominantly released from paints. Comparison of source contributions to ambient NMHCs at the two sites indicated that the contribution of LPG or natural gas at CW site was almost twice that at TW site. High correlation coefficients (R(2) > 0.8) between the measured and predicted values suggested that the PCA/APCS model was applicable for estimation

  1. Process for desulfurizing hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    1937-04-12

    A process is described for the desulfurization of a mixture of hydrocarbons, and in particular hydrocarbons containing less than 7 atoms of carbon and sulfur compounds of the type of sulfur carbonyl, characterized by the fact that the mixture, preferably in the liquid phase, is brought in contact with a solution of caustic alkali, essentially anhydrous or preferably with a solution of alkali hydroxide in an organic hydroxy nonacid solvent, for example, an alcohol, or with an alkaline alcoholate, under conditions suitable to the formation of hydrogen sulfide which produces a hydrocarbon mixture free from sulfur compounds of the sulfur carbonyl type but containing hydrogen sulfide, and that it is treated, following mixing, having beem submitted to the first treatment, by means of aqueous alkaline hydroxide to eliminate the hydrogen sulfide.

  2. Effect of estradiol and cloprostenol combination therapy on expulsion of mummified fetus and subsequent fertility in four crossbred cows

    Directory of Open Access Journals (Sweden)

    Arumugam Kumaresan

    2013-06-01

    Full Text Available Four crossbred cows with mummified fetus were utilized for the study. The cows weresubjected togynecologicalexamination and based on the findings the cases were diagnosed asmummified fetus. The cows were treated with 2 mg estradiol valerate and 500 μg cloprostenoland were examined every 12 hr after 24 hr of the treatment for cervical dilatation and othersigns related to fetal expulsion. The time duration between treatment and starting of cervicaldilatation ranged from 48 to 58h (53.00 ± 2.08 hr. Complete dilatation of cervix was observedafter 70.00 ± 2.94 hr post treatment (Range = 64-76 hr. The mean fetalcrown-rump length(CRL was 31.5 cm, which ranged from 27.5 to 38 cm. The number of cotyledons in pregnanthorn also showed wide variation (Range 24-38 numbers with mean ± SE of 30.3 ± 3.07numbers. In the placenta of three animals irregular shaped large adventitious cotyledons wereobserved in the inter-cotyledonary areas. Out of the four animals treated, three animals wereconceived within three estrous cycles and one animal had cystic ovary in the next cycle and wasnot conceived even after four cycles. It was concluded that the estradiolandprostaglandin F2α(PGF2αcombinationtherapy was effective for expulsion of mummified fetus in crossbred cowswithout affecting much on future fertility.

  3. Impaction and Prediction: Does Ureteral Wall Thickness Affect the Success of Medical Expulsive Therapy in Pediatric Ureteral Stones?

    Science.gov (United States)

    Tuerxun, Aierken; Batuer, Abudukahaer; Erturhan, Sakip; Eryildirim, Bilal; Camur, Emre; Sarica, Kemal

    2017-01-01

    The study aimed to evaluate the predictive value of ureteral wall thickness (UWT) and stone-related parameters for medical expulsive therapy (MET) success with an alpha blocker in pediatric upper ureteral stones. A total of 35 children receiving MET ureteral stones (Hounsfield unit), degree of hydronephrosis, and UWT were evaluated with patient demographics and recorded. The possible predictive value of these parameters in success rates and time to stone expulsion were evaluated in a comparative manner between the 2 groups. The overall mean patient age and stone size values were 5.40 ± 0.51 years and 6.24 ± 0.28 mm, respectively. Regarding the predictive values of these parameters for the success of MET, while stone size and UWT were found to be highly predictive for MET success, patients age, body mass index, stone density, and degree of hydronephrosis had no predictive value on this aspect. Our findings indicated that some stone and anatomical factors may be used to predict the success of MET in pediatric ureteral stones in an effective manner. With this approach, unnecessary use of these drugs that may cause a delay in removing the stone will be avoided, and the possible adverse effects of obstruction as well as stone-related clinical symptoms could be minimized. © 2017 S. Karger AG, Basel.

  4. Technical Evaluation Summary of the In Situ Vitrification Melt Expulsion at the Oak Ridge National Laboratory on April 21, 1996, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    1996-11-01

    This Technical Evaluation Summary of the In Situ Vitrification Melt Expulsion at the Oak Ridge National Laboratory on April 21, 1996, was prepared at the request of the Department of Energy as a supporting reference document for the Final Unusual Occurrence Report to fully explore the probable causes that lead to the subject incident. This document provides the Environmental Restoration Program with the technical information on the performance of the in situ vitrification treatability study operations at ORNL pit 1 up to and including the time of the melt expulsion incident. This document also attempts to diagnose the causes of the melt expulsion event the consequent damages to equipment the radiological impacts of the event, and the equipment design modifications and procedural changes necessary for future safe ISV operations

  5. Recovery of hydrocarbon oils

    Energy Technology Data Exchange (ETDEWEB)

    1941-02-10

    A process is disclosed for recovery of hydrocarbon oils, especially lubricating oils or diesel oils, through pressure hydrogenation of distillation, extraction of hydrogenation products from coal or coaly materials or from oils such as mineral oils or tars in liquid phase by use in a reaction vessel of fixed-bed catalysts, characterized in that as starting material is employed material which has been freed of asphaltic and resinous material by hydrogenation refining, vacuum-steam distillation, treatment with hydrogen-rich hydrocarbons (hydroforming), or sulfuric acid.

  6. Applications of contaminant fate and bioaccumulation models in assessing ecological risks of chemicals: A case study for gasoline hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    MacLeod, Matthew; McKone, Thomas E.; Foster, Karen L.; Maddalena, Randy L.; Parkerton, Thomas F.; Mackay, Don

    2004-02-01

    Mass balance models of chemical fate and transport can be applied in ecological risk assessments for quantitative estimation of concentrations in air, water, soil and sediment. These concentrations can, in turn, be used to estimate organism exposures and ultimately internal tissue concentrations that can be compared to mode-of-action-based critical body residues that correspond to toxic effects. From this comparison, risks to the exposed organism can be evaluated. To illustrate the practical utility of fate models in ecological risk assessments of commercial products, the EQC model and a simple screening level biouptake model including three organisms, (a bird, a mammal and a fish) is applied to gasoline. In this analysis, gasoline is divided into 24 components or ''blocks'' with similar environmental fate properties that are assumed to elicit ecotoxicity via a narcotic mode of action. Results demonstrate that differences in chemical properties and mode of entry into the environment lead to profound differences in the efficiency of transport from emission to target biota. We discuss the implications of these results and insights gained into the regional fate and ecological risks associated with gasoline. This approach is particularly suitable for assessing mixtures of components that have similar modes of action. We conclude that the model-based methodologies presented are widely applicable for screening level ecological risk assessments that support effective chemicals management.

  7. A biogeochemical transport model to simulate the attenuation of chlorinated hydrocarbon contaminant fluxes across the groundwater-surface water interface

    DEFF Research Database (Denmark)

    Malaguerra, Flavio; Binning, Philip John; Albrechtsen, Hans-Jørgen

    2009-01-01

    and biogeochemical transformation model of the discharge of a TCE plume into a stream, and to determine which parameters most strongly affect pollutant discharge concentrations. Here biological kinetics and the interaction with the soil matrix are implemented in PHREEQC. The ability of PHREEQC to deal with a large...

  8. Derivation and application of mathematical model for well test analysis with variable skin factor in hydrocarbon reservoirs

    Directory of Open Access Journals (Sweden)

    Pengcheng Liu

    2016-06-01

    Full Text Available Skin factor is often regarded as a constant in most of the mathematical model for well test analysis in oilfields, but this is only a kind of simplified treatment with the actual skin factor changeable. This paper defined the average permeability of a damaged area as a function of time by using the definition of skin factor. Therefore a relationship between a variable skin factor and time was established. The variable skin factor derived was introduced into existing traditional models rather than using a constant skin factor, then, this newly derived mathematical model for well test analysis considering variable skin factor was solved by Laplace transform. The dimensionless wellbore pressure and its derivative changed with dimensionless time were plotted with double logarithm and these plots can be used for type curve fitting. The effects of all the parameters in the expression of variable skin factor were analyzed based on the dimensionless wellbore pressure and its derivative. Finally, actual well testing data were used to fit the type curves developed which validates the applicability of the mathematical model from Sheng-2 Block, Shengli Oilfield, China.

  9. Integrated 3D Reservoir/Fault Property Modelling Aided Well Planning and Improved Hydrocarbon Recovery in a Niger Delta Field

    International Nuclear Information System (INIS)

    Onyeagoro, U. O.; Ebong, U. E.; Nworie, E. A.

    2002-01-01

    The large and varied portfolio of assets managed by oil companies requires quick decision-making and the deployment of best in class technologies in asset management. Timely decision making and the application of the best technologies in reservoir management are however sometimes in conflict due to large time requirements of the latter.Optimizing the location of development wells is critical to account for variable fluid contact movements and pressure interference effects between wells, which can be significant because of the high permeability (Darcy range) of Niger Delta reservoirs. With relatively high drilling costs, the optimization of well locations necessitates a good realistic static and dynamic 3D reservoir description, especially in the recovery of remaining oil and oil rim type of reservoirs.A detailed 3D reservoir model with fault properties was constructed for a Niger delta producing field. This involved the integration of high quality 3D seismic, core, petrophysics, reservoir engineering, production and structural geology data to construct a realistic 3D reservoir/fault property model for the field. The key parameters considered during the construction of the internal architecture of the model were the vertical and horizontal reservoir heterogeneities-this controls the fluid flow within the reservoir. In the production realm, the fault thickness and fault permeabilities are factors that control the impedance of fluid flow across the fault-fault transmissibility. These key internal and external reservoir/structural variables were explicitly modeled in a 3D modeling software to produce different realizations and manage the uncertainties.The resulting 3D reservoir/fault property model was upscaled for simulation purpose such that grid blocks along the fault planes have realistic transmissibility multipliers of 0 to 1 attached to them. The model was also used in the well planner to optimize the positioning of a high angle deviated well that penetrated

  10. Optrode for sensing hydrocarbons

    Science.gov (United States)

    Miller, H.; Milanovich, F.P.; Hirschfeld, T.B.; Miller, F.S.

    1988-09-13

    A two-phase system employing the Fujiwara reaction is provided for the fluorometric detection of halogenated hydrocarbons. A fiber optic is utilized to illuminate a column of pyridine trapped in a capillary tube coaxially attached at one end to the illuminating end of the fiber optic. A strongly alkaline condition necessary for the reaction is maintained by providing a reservoir of alkali in contact with the column of pyridine, the surface of contact being adjacent to the illuminating end of the fiber optic. A semipermeable membrane caps the other end of the capillary tube, the membrane being preferentially permeable to the halogenated hydrocarbon and but preferentially impermeable to water and pyridine. As the halogenated hydrocarbon diffuses through the membrane and into the column of pyridine, fluorescent reaction products are formed. Light propagated by the fiber optic from a light source, excites the fluorescent products. Light from the fluorescence emission is also collected by the same fiber optic and transmitted to a detector. The intensity of the fluorescence gives a measure of the concentration of the halogenated hydrocarbons. 5 figs.

  11. Catalyst for hydrocarbon conversion

    International Nuclear Information System (INIS)

    Duhaut, P.; Miquel, J.

    1975-01-01

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

  12. Modelling of turbulent hydrocarbon combustion. Test of different reactor concepts for describing the interactions between turbulence and chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, C; Kremer, H [Ruhr-Universitaet Bochum, Lehrstuhl fuer Energieanlagentechnik, Bochum (Germany); Kilpinen, P; Hupa, M [Aabo Akademi, Turku (Finland). Combustion Chemistry Research Group

    1998-12-31

    The detailed modelling of turbulent reactive flows with CFD-codes is a major challenge in combustion science. One method of combining highly developed turbulence models and detailed chemistry in CFD-codes is the application of reactor based turbulence chemistry interaction models. In this work the influence of different reactor concepts on methane and NO{sub x} chemistry in turbulent reactive flows was investigated. Besides the classical reactor approaches, a plug flow reactor (PFR) and a perfectly stirred reactor (PSR), the Eddy-Dissipation Combustion Model (EDX) and the Eddy Dissipation Concept (EDC) were included. Based on a detailed reaction scheme and a simplified 2-step mechanism studies were performed in a simplified computational grid consisting of 5 cells. The investigations cover a temperature range from 1273 K to 1673 K and consider fuel-rich and fuel-lean gas mixtures as well as turbulent and highly turbulent flow conditions. All test cases investigated in this study showed a strong influence of the reactor residence time on the species conversion processes. Due to this characteristic strong deviations were found for the species trends resulting from the different reactor approaches. However, this influence was only concentrated on the `near burner region` and after 4-5 cells hardly any deviation and residence time dependence could be found. The importance of the residence time dependence increased when the species conversion was accelerated as it is the case for overstoichiometric combustion conditions and increased temperatures. The study focused furthermore on the fine structure in the EDC. Unlike the classical approach this part of the cell was modelled as a PFR instead of a PSR. For high temperature conditions there was hardly any difference between both reactor types. However, decreasing the temperature led to obvious deviations. Finally, the effect of the selective species transport between the cells on the conversion process was investigated

  13. Modelling of turbulent hydrocarbon combustion. Test of different reactor concepts for describing the interactions between turbulence and chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, C.; Kremer, H. [Ruhr-Universitaet Bochum, Lehrstuhl fuer Energieanlagentechnik, Bochum (Germany); Kilpinen, P.; Hupa, M. [Aabo Akademi, Turku (Finland). Combustion Chemistry Research Group

    1997-12-31

    The detailed modelling of turbulent reactive flows with CFD-codes is a major challenge in combustion science. One method of combining highly developed turbulence models and detailed chemistry in CFD-codes is the application of reactor based turbulence chemistry interaction models. In this work the influence of different reactor concepts on methane and NO{sub x} chemistry in turbulent reactive flows was investigated. Besides the classical reactor approaches, a plug flow reactor (PFR) and a perfectly stirred reactor (PSR), the Eddy-Dissipation Combustion Model (EDX) and the Eddy Dissipation Concept (EDC) were included. Based on a detailed reaction scheme and a simplified 2-step mechanism studies were performed in a simplified computational grid consisting of 5 cells. The investigations cover a temperature range from 1273 K to 1673 K and consider fuel-rich and fuel-lean gas mixtures as well as turbulent and highly turbulent flow conditions. All test cases investigated in this study showed a strong influence of the reactor residence time on the species conversion processes. Due to this characteristic strong deviations were found for the species trends resulting from the different reactor approaches. However, this influence was only concentrated on the `near burner region` and after 4-5 cells hardly any deviation and residence time dependence could be found. The importance of the residence time dependence increased when the species conversion was accelerated as it is the case for overstoichiometric combustion conditions and increased temperatures. The study focused furthermore on the fine structure in the EDC. Unlike the classical approach this part of the cell was modelled as a PFR instead of a PSR. For high temperature conditions there was hardly any difference between both reactor types. However, decreasing the temperature led to obvious deviations. Finally, the effect of the selective species transport between the cells on the conversion process was investigated

  14. Numerical modelling of the work of a pulsed aerosol system for fire fighting at the ignitions of liquid hydrocarbon fuels

    Science.gov (United States)

    Rychkov, A. D.

    2009-06-01

    The work of a pulsed aerosol system for fire fighting is modelled, which is designed for fire fighting at oil storages and at the spills of oil products, whose vapors were modelled by gaseous methane. The system represents a device for separate installation, which consists of a charge of solid propellant (the gas generator) and a container with fine-dispersed powder of the flame-damper substance. The methane combustion was described by a one-stage gross-reaction, the influence of the concentration of vapors of the flame-damper substance on the combustion process was taken into account by reducing the pre-exponent factor in the Arrhenius law and was described by an empirical dependence. The computational experiment showed that the application of the pulsed aerosol system for fire fighting ensures an efficient transport of fine-dispersed aerosol particles of the flame-damping substance and its forming vapors to the combustion zone; the concentration of particles ensures the damping of the heat source.

  15. Role of alpha-1 blocker in expulsion of stone fragments after extracorporeal shock wave lithotripsy for renal stones

    International Nuclear Information System (INIS)

    Pirzada, A.J.; Anwar, A.; Javed, A.; Memon, I.; Mohammad, A.

    2011-01-01

    Background: Renal stone disease is a significant and worldwide health problem. Recent advances in stone management have allowed kidney stones to be treated using extracorporeal shock wave lithotripsy (ESWL), uretero-renoscopy (URS), and percutaneous nephrostolithotomy (PCNL). Recently, medical expulsion therapy (MET) has been investigated as a supplement to observation in an effort to improve spontaneous stone passage rates. Patients and Methods: This study was a randomized, controlled, prospective study to determine whether the administration of Alpha-1-adrenergic receptor antagonists as an adjunctive medical therapy, increases the efficacy of ESWL to treat renal stones. Sixty patients with renal stones of 0.5-1.5 Cm in size (average size 1.2 Cm) were included in this study underwent ESWL followed by administration of Alpha-1-adrenergic receptor antagonists at department of Urology Liaquat National Hospital Karachi from Feb 2008 to Sept 2008. This was a comparative study and patients were divided into two groups. In group A patients received conventional treatment Diclofenac sodium, Anti Spasmodic (Drotaverine HCl) as required and Proton Pump inhibitor (Omeprazole 20 mg) once daily after shock wave lithotripsy. In group B patients received alpha-1 blocker, Alfuzosin HCl 5 mg twice daily in addition to conventional treatment. All patients were instructed to drink a minimum of 2 litres water daily. Ultrasound guided Dornier Alpha Impact Lithotripter was utilised for shock wave lithotripsy. Results: Of the 60 patients, 76.7% of those receiving Alfuzosin and 46.7% of controls had achieved clinical success at 1 month (p=0.01). The mean cumulative diclofenac dose was 485 mg per patient in the Alfuzosin group and 768 mg per patient in the control group (p=0.002). This difference was statistically significant. Conclusion: Alfuzosin therapy as an adjunctive medical therapy after ESWL is more effective than lithotripsy alone for the treatment of patients with large renal

  16. Liquid-liquid equilibria for binary and ternary systems containing glycols, aromatic hydrocarbons, and water: Experimental measurements and modeling with the CPA EoS

    DEFF Research Database (Denmark)

    Folas, Georgios; Kontogeorgis, Georgios; Michelsen, Michael Locht

    2006-01-01

    Liquid-liquid equilibrium data of four binary glycol + aromatic hydrocarbon systems and three ternary systems containing water have been measured at atmospheric pressure. The measured systems are monoethylene glycol (MEG) + benzene or toluene, triethylene glycol (TEG) + benzene or toluene, MEG...... + water + benzene, MEG + water + toluene, and TEG + water + toluene. The binary systems are correlated with the Cubic-Plus-Association (CPA) equation of state while the ternary systems are predicted from interaction parameters obtained from the binary systems. Very satisfactory liquid-liquid equilibrium...... correlations are obtained for the binary systems using temperature-independent interaction parameters, while adequate predictions are achieved for multicomponent water + glycol + aromatic hydrocarbons systems when accounting for the solvation between the aromatic hydrocarbons and glycols or water....

  17. Kinetic Models Study of Hydrogenation of Aromatic Hydrocarbons in Vacuum Gas Oil and Basrah Crude Oil Reaction

    Directory of Open Access Journals (Sweden)

    Muzher M. Ibraheem

    2013-05-01

    Full Text Available             The aim of this research is to study the kinetic reaction models for catalytic hydrogenation of aromatic content for Basrah crude oil (BCO and vacuum gas oil (VGO derived from Kirkuk crude oil which has the boiling point rang of (611-833K.            This work is performed using a hydrodesulphurization (HDS pilot plant unit located in AL-Basil Company. A commercial (HDS catalyst cobalt-molybdenum (Co-Mo supported in alumina (γ-Al2O3 is used in this work. The feed is supplied by North Refinery Company in Baiji. The reaction temperatures range is (600-675 K over liquid hourly space velocity (LHSV range of (0.7-2hr-1 and hydrogen pressure is 3 MPa with H2/oil ratio of 300 of Basrah Crude oil (BCO, while the corresponding conditions for vacuum gas oil (VGO are (583-643 K, (1.5-3.75 hr-1, 3.5 MPa and 250  respectively .            The results showed that the reaction kinetics is of second order for both types of feed. Activation energies are found to be 30.396, 38.479 kJ/mole for Basrah Crude Oil (BCO and Vacuum Gas Oil (VGO respectively.

  18. Method for inverting reflection trace data from 3-D and 4-D seismic surveys and identifying subsurface fluid and pathways in and among hydrocarbon reservoirs based on impedance models

    Science.gov (United States)

    He, W.; Anderson, R.N.

    1998-08-25

    A method is disclosed for inverting 3-D seismic reflection data obtained from seismic surveys to derive impedance models for a subsurface region, and for inversion of multiple 3-D seismic surveys (i.e., 4-D seismic surveys) of the same subsurface volume, separated in time to allow for dynamic fluid migration, such that small scale structure and regions of fluid and dynamic fluid flow within the subsurface volume being studied can be identified. The method allows for the mapping and quantification of available hydrocarbons within a reservoir and is thus useful for hydrocarbon prospecting and reservoir management. An iterative seismic inversion scheme constrained by actual well log data which uses a time/depth dependent seismic source function is employed to derive impedance models from 3-D and 4-D seismic datasets. The impedance values can be region grown to better isolate the low impedance hydrocarbon bearing regions. Impedance data derived from multiple 3-D seismic surveys of the same volume can be compared to identify regions of dynamic evolution and bypassed pay. Effective Oil Saturation or net oil thickness can also be derived from the impedance data and used for quantitative assessment of prospective drilling targets and reservoir management. 20 figs.

  19. Simulation of urinary excretion of 1-hydroxypyrene in various scenarios of exposure to polycyclic aromatic hydrocarbons with a generic, cross-chemical predictive PBTK-model.

    Science.gov (United States)

    Jongeneelen, Frans; ten Berge, Wil

    2012-08-01

    A physiologically based toxicokinetic (PBTK) model can predict blood and urine concentrations, given a certain exposure scenario of inhalation, dermal and/or oral exposure. The recently developed PBTK-model IndusChemFate is a unified model that mimics the uptake, distribution, metabolism and elimination of a chemical in a reference human of 70 kg. Prediction of the uptake by inhalation is governed by pulmonary exchange to blood. Oral uptake is simulated as a bolus dose that is taken up at a first-order rate. Dermal uptake is estimated by the use of a novel dermal physiologically based module that considers dermal deposition rate and duration of deposition. Moreover, evaporation during skin contact is fully accounted for and related to the volatility of the substance. Partitioning of the chemical and metabolite(s) over blood and tissues is estimated by a Quantitative Structure-Property Relationship (QSPR) algorithm. The aim of this study was to test the generic PBTK-model by comparing measured urinary levels of 1-hydroxypyrene in various inhalation and dermal exposure scenarios with the result of model simulations. In the last three decades, numerous biomonitoring studies of PAH-exposed humans were published that used the bioindicator 1-hydroxypyrene (1-OH-pyrene) in urine. Longitudinal studies that encompass both dosimetry and biomonitoring with repeated sampling in time were selected to test the accuracy of the PBTK-model by comparing the reported concentrations of 1-OHP in urine with the model-predicted values. Two controlled human volunteer studies and three field studies of workers exposed to polycyclic aromatic hydrocarbons (PAH) were included. The urinary pyrene-metabolite levels of a controlled human inhalation study, a transdermal uptake study of bitumen fume, efficacy of respirator use in electrode paste workers, cokery workers in shale oil industry and a longitudinal study of five coke liquefaction workers were compared to the PBTK-predicted values. The

  20. MIGRATION AND CHINESE ENTREPRENEURS IN MAZATLAN. SINCE ARRIVING IN MID- NINETEENTH CENTURY UNTIL THEIR EXPULSION IN 1930

    Directory of Open Access Journals (Sweden)

    R. Arturo Román Alarcón

    2014-07-01

    Full Text Available The Chinese migration to Mazatlan and Mexico, began in the mid-nineteenth century, via San Francisco. They were the most important foreign colony from the early decades of the twentieth century. On arrival the Chinese population lacked capital as largely devoted to provide their services as domestic workers, especially farmers and craft activities related to repairing and making shoes. With the advent of the twentieth century and the accumulation of some capital, began its foray into the retail trade, which was the domain of national merchants. The commercial importance of the Chinese was one of the causes of the hostility of Mexican traders, which coupled with the counter-arguments raised by the Labor Law, Health Code, the culmination of the Treaty with China and the effects of the 1929 crisis, served as sustenance for their expulsion in 1932.

  1. The counterfeit nephew of the Pope. A plot against the Bishop of Puebla during the expulsion of the Jesuits

    Directory of Open Access Journals (Sweden)

    Gabriel Torres Puga

    2016-01-01

    Full Text Available In 1767, an ex-Jesuit and an Italian adventurer met in the Episcopal jail in Puebla. The grievances of the former, a staunch critic of Bishop Francisco Fabián y Fuero, found a means of expression in the illusions of the latter, who pretended to be the Pope’s nephew. The result was a strange plan that took on a “seditious” character as it combined with the gossip surrounding the expulsion of the Jesuits. This article uses a variety of legal documents and secret investigations to reconstruct this history of lies, intrigue and the desire for critical expression, providing an opportunity to reflect on the dissent of the American clergy during a time in which royalty and censorship were being redefined.

  2. Seabed fluid expulsion along the upper slope and outer shelf of the U.S. Atlantic continental margin

    Science.gov (United States)

    Brothers, D.S.; Ruppel, C.; Kluesner, J.W.; ten Brink, Uri S.; Chaytor, J.D.; Hill, J.C.; Andrews, B.D.; Flores, C.

    2014-01-01

    Identifying the spatial distribution of seabed fluid expulsion features is crucial for understanding the substrate plumbing system of any continental margin. A 1100 km stretch of the U.S. Atlantic margin contains more than 5000 pockmarks at water depths of 120 m (shelf edge) to 700 m (upper slope), mostly updip of the contemporary gas hydrate stability zone (GHSZ). Advanced attribute analyses of high-resolution multichannel seismic reflection data reveal gas-charged sediment and probable fluid chimneys beneath pockmark fields. A series of enhanced reflectors, inferred to represent hydrate-bearing sediments, occur within the GHSZ. Differential sediment loading at the shelf edge and warming-induced gas hydrate dissociation along the upper slope are the proposed mechanisms that led to transient changes in substrate pore fluid overpressure, vertical fluid/gas migration, and pockmark formation.

  3. Performance estimation of ejector cycles using heavier hydrocarbon refrigerants

    International Nuclear Information System (INIS)

    Kasperski, Jacek; Gil, Bartosz

    2014-01-01

    Computer software basing on theoretical model of Huang et al. with thermodynamic properties of hydrocarbons was prepared. Investigation was focused on nine hydrocarbons: propane, butane, iso-butane, pentane, iso-pentane, hexane, heptane and octane. A series of calculations was carried out for the generator temperature between 70 and 200 °C, with assumed temperatures of evaporation 10 °C and condensation 40 °C. Calculation results show that none of the hydrocarbons enables high efficiency of a cycle in a wide range of temperature. Each hydrocarbon has its own maximal entrainment ratio at its individual temperature of optimum. Temperatures of entrainment ratios optimum increase according to the hydrocarbon heaviness with simultaneous increase of entrainment ratio peak values. Peak values of the COP do not increase according to the hydrocarbons heaviness. The highest COP = 0.32 is achieved for iso-butane at 102 °C and the COP = 0.28 for pentane at 165 °C. Heptane and octane can be ignored. - Highlights: • Advantages of use of higher hydrocarbons as ejector refrigerants were presumed. • Computer software basing on theoretical model of Huang et al. (1999) was prepared. • Optimal temperature range of vapor generation for each hydrocarbon was calculated

  4. Vulnerability and the Right to Respect for Private Life as an Autonomous Source of Protection against Expulsion under Article 8 ECHR

    Directory of Open Access Journals (Sweden)

    Sylvie Da Lomba

    2017-12-01

    Full Text Available This paper focuses on settled migrants and calls for the construction of the right to respect for private life as an autonomous source of protection against expulsion under Article 8 ECHR. I contend that, as a core part of human existence, private life warrants meaningful protection. I posit that the fact that all settled migrants have established private life in the host State brings it to the fore of Article 8 expulsion cases. This argument finds strong support in the concept of belonging and transnational migration theory; both tell us that settled migrants’ host State has become their ‘own country’. Drawing on earlier work, I reclaim vulnerability as a foundation and tool of International Human Rights Law with a view to recognising migrants within the jurisdiction of ECHR States as fully-fledged ECHR subjects and making the European Court of Human Rights responsive to their vulnerability. I make the case for absolute protection against expulsion for second (and subsequent-generation migrants and settled migrants who have spent most of their adult life in the host State. In respect of other settled migrants, I argue that the minimum protection standard should be that expulsion is only justifiable in exceptional circumstances.

  5. Distilling hydrocarbons, etc

    Energy Technology Data Exchange (ETDEWEB)

    Turner, C

    1917-11-23

    In the fractional or destructive distillation of hydrocarbon oils or other liquids, the pressure in the still is raised and lowered alternately. The still is closed to raise the pressure, and is opened to lower the pressure rapidly solely by expansion of the vapors. The operation is effected without intermittent cooling, except such as may occur during the lowering of the pressure. In distilling hydrocarbon oil, pressure steam is blown into the oil until the pressure reaches 5 lb/in./sup 2/. The vapor outlet is then opened until the pressure falls to 2 lb/in./sup 2/, whereupon the vapor outlet is closed and steam is again admitted. The operation is continued until the steam, which is of 20 lb pressure, no longer effects distillation; after this stage, superheated steam is used.

  6. Distilling hydrocarbon oils

    Energy Technology Data Exchange (ETDEWEB)

    Tausz, J

    1924-07-16

    Hydrocarbon oils such as petroleum, shale oils, lignite or coal tar oils are purified by distilling them and collecting the distillate in fractions within narrow limits so that all the impurities are contained in one or more of the narrow fractions. In distilling ligroin obtained by destructive distillation of brown coal, it is found that the coloring and resin-forming constituents are contained in the fractions distilling over at 62 to 86/sup 0/C and 108/sup 0/C. The ligroin is purified, therefore, by distillating in an apparatus provided with an efficient dephlegmotor and removing these two fractions. The distillation may be carried out wholly or in part under reduced pressure, and fractions separated under ordinary pressure may be subsequently distilled under reduced pressure. The hydrocarbons may be first separated into fractions over wider limits and the separate fractions be subjected to a further fractional distillation.

  7. Nuclear explosives and hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, P

    1971-10-01

    A nuclear explosive 12 in. in diam and producing very little tritium is feasible in France. Such a device would be well adapted for contained nuclear explosions set off for the purpose of hydrocarbon storage or stimulation. The different aspects of setting off the explosive are reviewed. In the particular case of gas storage in a nuclear cavity in granite, it is demonstrated that the dose of irradiation received is extremely small. (18 refs.)

  8. Treatment of hydrocarbon oils

    Energy Technology Data Exchange (ETDEWEB)

    1936-02-22

    A process is described for refining a mixture of liquid hydrocarbons containing harmful substances, this process permitting the operation, which consists in treating the liquid mixture at a temperature higher than 200/sup 0/C with a solid catalyst of phosphoric acid, consisting of phosphoric acid deposited on a solid support of the type of metallurgical coke, for a time sufficient to convert the harmful components to inoffensive substances.

  9. Biogeochemistry of Halogenated Hydrocarbons

    Science.gov (United States)

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

    2003-12-01

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

  10. Cracking hydrocarbon oils

    Energy Technology Data Exchange (ETDEWEB)

    Seigle, A A.F.M.

    1922-12-20

    Hydrocarbon oils such as petroleum, peat, shale, or lignite oils, heavy tars, resin oils, naphthalene oils, etc., are vaporized by being fed from a tank through a preheater to the lower part of a vertical annular retort heated by a flame projected down the central cavity from a burner. The oil vapors rise through annular passages formed by disks, on which are placed chips of copper, iron, aluminum, etc., to act as catalysts.

  11. High boiling point hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Pier, M

    1929-04-29

    A process is given for the production of hydrocarbons of high boiling point, such as lubricating oils, from bituminous substances, such as varieties of coal, shale, or other solid distillable carbonaceous materials. The process consists of treating the initial materials with organic solvents and then subjecting the products extracted from the initial materials, preferably directly, to a reducing treatment in respect to temperature, pressure, and time. The reduction treatment is performed by means of hydrogen under pressure.

  12. Direct hydrocarbon fuel cells

    Science.gov (United States)

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

    2010-05-04

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

  13. ENA of heterocyclic hydrocarbons by adding hydrogen peroxide in groundwater circulation wells - a field-based study on a large physical model scale

    International Nuclear Information System (INIS)

    Sagner, A.; Tiehm, A.; Trotschler, O.; Haslwimmer, Th.; Koschitzky, H.P.

    2005-01-01

    Heterocyclic Hydrocarbons (NSO-HET) are ingredients of tar oil, commonly found down-gradient of former gasworks sites. Typical NSO-HET are benzofurans, methyl-benzofurans, methylquinoline, acridine or carbazole. During investigations of MNA (monitored natural attenuation) remediation strategies, it was found that most NSO-HET are highly mobile due to their high water solubility and low biodegradation rates. In addition, some were found to be highly toxic and carcinogenic. In particular under anaerobic conditions, NSO-HET biodegradation rates are low. However, aerobic biological degradation was found to be effective. Based on the extension and contaminant distribution of the plume (∼ 800 m long) down-gradient of a former gasworks 'Testfeld Sued' (TFS) in Southern Germany, the most applicable technology for enhancing the natural degradation of PAH, BTEX and NSO-HET was selected and tested under controlled conditions in a large physical model (Large Flume of VEGAS). The investigations focused on a technology for a homogeneous infiltration of electron acceptor solutions such as oxygen and hydrogen peroxide to provide the bacteria with molecular oxygen. An initial infiltration of oxygen (air-saturated water) during the adaptation of microorganism to aerobic biodegradation was followed by a time-limited addition of hydrogen peroxide to achieve an oxygen concentration up to 23 mg/L in the model aquifer. An almost complete degradation of NSO-HET was found. On the basis of numerical simulations and lab experiments, it was found that natural dispersion will not lead to a wide-ranging homogeneous distribution and mixing of the oxygen in the aquifer. The Groundwater Circulation Wells technology (GCW) can be applied to achieve a maximum mixing of the electron acceptor solution with the groundwater. A spherical groundwater circulation is induced by means of ex- and infiltration ports in vertical wells. Infiltration and ex-filtration ports are located in hydraulically separated

  14. Measurement of polynuclear aromatic hydrocarbons (PAHs) in epiphytic lichens and from PM 2.5 filters for receptor modeling in the Alberta Oil Sands Region (Invited)

    Science.gov (United States)

    Studabaker, W. B.; Jayanty, J.; Raymer, J. H.; Krupa, S.

    2013-12-01

    As mining and refinery operations in the Alberta Oil Sands Region (AOSR) have expanded, there has been increasing concern for the impacts of air pollution generated by those operations on both human and ecosystem health. The inaccessibility of much of the AOSR makes it difficult to establish conventional air quality monitoring stations to the extent needed to model long-range impacts of emissions from the AOSR operations. Epiphytic lichens are important markers of ecosystem health, are well-established bioaccumulators of trace metals, and are potentially useful biomonitors of air pollution. However, their ability to take up organic pollutants has not been extensively explored, and only recently have they been used for biomonitoring of pollution by PAHs. Here we describe the determination of polynuclear aromatic hydrocarbons (PAHs) in lichens, collected from sites throughout the AOSR, for modeling emissions associated with mining and oil extraction operations. We also describe preliminary results of the determination of PAHs in PM 2.5 filters from dichotomous samplers stationed in the AOSR, in the context of the biological sample data. Lichens (Hypogymnia physodes) were collected on two separate occasions. During the summer of 2009, single samples were taken from 200 sites in the AOSR; a subset of 20 of these was selected for determination of PAHs. During the summer of 2011, triplicate samples (from separate trees within a site) were collected from 20 sites representing similar locations to the 2008 sites. Lichens were milled in a cryogenic impactor, then were extracted with cyclohexane. Extracts were purified on silica gel using automated solid phase extraction and analyzed by gas chromatography with mass selective detection. Method detection limits for individual PAHs were 2-4 ng/g. Total PAHs in the samples from both collection events ranged from 50 ng/g to 350 ng/g, and declined with increasing distance from the mining and refinery operations. The relative

  15. GEOELECTRICAL STRATIGRAPHY AND ANALYSIS OF A HYDROCARBON IMPACTED AQUIFER

    Science.gov (United States)

    A recently proposed geoelectrical model for hydrocarbon impacted sites predicts anomalously high conductivities coincident with aged contaminated zones. These high conductivities are attributed to an enhancement of mineral weathering resulting from byproducts of microbial redox p...

  16. Measuring Trace Hydrocarbons in Silanes

    Science.gov (United States)

    Lesser, L. A.

    1984-01-01

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

  17. Thermodynamic model for predicting equilibrium conditions of clathrate hydrates of noble gases + light hydrocarbons: Combination of Van der Waals–Platteeuw model and sPC-SAFT EoS

    International Nuclear Information System (INIS)

    Abolala, Mostafa; Varaminian, Farshad

    2015-01-01

    Highlights: • Applying sPC-SAFT for phase equilibrium calculations. • Determining Kihara potential parameters for hydrate formers. • Successful usage of the model for systems with hydrate azeotropes. - Abstract: In this communication, equilibrium conditions of clathrate hydrates containing mixtures of noble gases (Argon, Krypton and Xenon) and light hydrocarbons (C 1 –C 3 ), which form structure I and II, are modeled. The thermodynamic model is based on the solid solution theory of Van der Waals–Platteeuw combined with the simplified Perturbed-Chain Statistical Association Fluid Theory equation of state (sPC-SAFT EoS). In dispersion term of sPC-SAFT EoS, the temperature dependent binary interaction parameters (k ij ) are adjusted; taking advantage of the well described (vapor + liquid) phase equilibria. Furthermore, the Kihara potential parameters are optimized based on the P–T data of pure hydrate former. Subsequently, these obtained parameters are used to predict the binary gas hydrate dissociation conditions. The equilibrium conditions of the binary gas hydrates predicted by this model agree well with experimental data (overall AAD P ∼ 2.17)

  18. Effects of smectite on the oil-expulsion efficiency of the Kreyenhagen Shale, San Joaquin Basin, California, based on hydrous-pyrolysis experiments

    Science.gov (United States)

    Lewan, Michael D.; Dolan, Michael P.; Curtis, John B.

    2014-01-01

    The amount of oil that maturing source rocks expel is expressed as their expulsion efficiency, which is usually stated in milligrams of expelled oil per gram of original total organic carbon (TOCO). Oil-expulsion efficiency can be determined by heating thermally immature source rocks in the presence of liquid water (i.e., hydrous pyrolysis) at temperatures between 350°C and 365°C for 72 hr. This pyrolysis method generates oil that is compositionally similar to natural crude oil and expels it by processes operative in the subsurface. Consequently, hydrous pyrolysis provides a means to determine oil-expulsion efficiencies and the rock properties that influence them. Smectite in source rocks has previously been considered to promote oil generation and expulsion and is the focus of this hydrous-pyrolysis study involving a representative sample of smectite-rich source rock from the Eocene Kreyenhagen Shale in the San Joaquin Basin of California. Smectite is the major clay mineral (31 wt. %) in this thermally immature sample, which contains 9.4 wt. % total organic carbon (TOC) comprised of type II kerogen. Compared to other immature source rocks that lack smectite as their major clay mineral, the expulsion efficiency of the Kreyenhagen Shale was significantly lower. The expulsion efficiency of the Kreyenhagen whole rock was reduced 88% compared to that of its isolated kerogen. This significant reduction is attributed to bitumen impregnating the smectite interlayers in addition to the rock matrix. Within the interlayers, much of the bitumen is converted to pyrobitumen through crosslinking instead of oil through thermal cracking. As a result, smectite does not promote oil generation but inhibits it. Bitumen impregnation of the rock matrix and smectite interlayers results in the rock pore system changing from water wet to bitumen wet. This change prevents potassium ion (K+) transfer and dissolution and precipitation reactions needed for the conversion of smectite to

  19. The role of aryl hydrocarbon receptor signaling pathway in cardiotoxicity of acute lead intoxication in vivo and in vitro rat model.

    Science.gov (United States)

    Ansari, Mushtaq A; Maayah, Zaid H; Bakheet, Saleh A; El-Kadi, Ayman O; Korashy, Hesham M

    2013-04-05

    Lead (Pb(2+)) is a naturally occurring systemic toxicant heavy metal that affects several organs in the body including the kidneys, liver, and central nervous system. However, Pb(2+)-induced cardiotoxicity has never been investigated yet and the exact mechanism of Pb(2+) associated cardiotoxicity has not been studied. The current study was designed to investigate the potential effect of Pb(2+) to induce cardiotoxicity in vivo and in vitro rat model and to explore the molecular mechanisms and the role of aryl hydrocarbon receptor (AhR) and regulated gene, cytochrome P4501A1 (CYP1A1), in Pb(2+)-mediated cardiotoxicity. For these purposes, Wistar albino rats were treated with Pb(2+) (25, 50 and 100mg/kg, i.p.) for three days and the effects on physiological and histopathological parameters of cardiotoxicity were determined. At the in vitro level, rat cardiomyocyte H9c2 cell lines were incubated with increasing concentration of Pb(2+) (25, 50, and 100 μM) and the expression of hypertrophic genes, α- and β-myosin heavy chain (α-MHC and β-MHC), brain Natriuretic Peptide (BNP), and CYP1A1 were determined at the mRNA and protein levels using real-time PCR and Western blot analysis, respectively. The results showed that Pb(2+) significantly induced cardiotoxicity and heart failure as evidenced by increase cardiac enzymes, lactate dehydrogenase and creatine kinase and changes in histopathology in vivo. In addition, Pb(2+) treatment induced β-MHC and BNP whereas inhibited α-MHC mRNA and protein levels in vivo in a dose-dependent manner. In contrast, at the in vitro level, Pb(2+) treatment induced both β-MHC and α-MHC mRNA levels in time- and dose-dependent manner. Importantly, these changes were accompanied with a proportional increase in the expression of CYP1A1 mRNA and protein expression levels, suggesting a role for the CYP1A1 in cardiotoxicity. The direct evidence for the involvement of CYP1A1 in the induction of cardiotoxicity by Pb(2+) was evidenced by the

  20. Noble gas and hydrocarbon tracers in multiphase unconventional hydrocarbon systems: Toward integrated advanced reservoir simulators

    Science.gov (United States)

    Darrah, T.; Moortgat, J.; Poreda, R. J.; Muehlenbachs, K.; Whyte, C. J.

    2015-12-01

    Although hydrocarbon production from unconventional energy resources has increased dramatically in the last decade, total unconventional oil and gas recovery from black shales is still less than 25% and 9% of the totals in place, respectively. Further, the majority of increased hydrocarbon production results from increasing the lengths of laterals, the number of hydraulic fracturing stages, and the volume of consumptive water usage. These strategies all reduce the economic efficiency of hydrocarbon extraction. The poor recovery statistics result from an insufficient understanding of some of the key physical processes in complex, organic-rich, low porosity formations (e.g., phase behavior, fluid-rock interactions, and flow mechanisms at nano-scale confinement and the role of natural fractures and faults as conduits for flow). Noble gases and other hydrocarbon tracers are capably of recording subsurface fluid-rock interactions on a variety of geological scales (micro-, meso-, to macro-scale) and provide analogs for the movement of hydrocarbons in the subsurface. As such geochemical data enrich the input for the numerical modeling of multi-phase (e.g., oil, gas, and brine) fluid flow in highly heterogeneous, low permeability formations Herein we will present a combination of noble gas (He, Ne, Ar, Kr, and Xe abundances and isotope ratios) and molecular and isotopic hydrocarbon data from a geographically and geologically diverse set of unconventional hydrocarbon reservoirs in North America. Specifically, we will include data from the Marcellus, Utica, Barnett, Eagle Ford, formations and the Illinois basin. Our presentation will include geochemical and geological interpretation and our perspective on the first steps toward building an advanced reservoir simulator for tracer transport in multicomponent multiphase compositional flow (presented separately, in Moortgat et al., 2015).

  1. Fractional separation of hydrocarbon vapours

    Energy Technology Data Exchange (ETDEWEB)

    1937-07-10

    A process is described for converting higher boiling hydrocarbons to lower boiling hydrocarbons by subjecting them at elevated temperatures to a conversion operation, then separating the higher and lower boiling fractions. The separation takes place while the reaction products are maintained in the vapor phase by contact with a mass of solid porous material which has little or no catalytic activity but does have a preferential absorption property for higher boiling hydrocarbons so that the lower boiling part of the reaction products pass through the separation zone while the heavier hydrocarbons are retained. The separation is accomplished without substantial loss of heat of these reaction products.

  2. Process for preparing hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Krauch, C; Anther, E; Pier, M

    1926-04-07

    A process is described for the conversion of coal of all kinds, wood, oil, shale, as well as other carbonaceous materials into liquid hydrocarbons in two steps, characterized by treatment of the coal and so forth with a stream of hydrogen or hydrogen-containing gases at raised temperatures and raised pressures and producing a tarry product which, after separation of the ashlike residue, is converted by a further treatment, in the presence of catalysts, with hydrogen or hydrogen-containing gases at raised temperature and pressure, largely into low-boiling products.

  3. Recovering valuable liquid hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Pier, M

    1931-06-11

    A process for recovering valuable liquid hydrocarbons from coking coal, mineral coal, or oil shale through treatment with hydrogen under pressure at elevated temperature is described. Catalysts and grinding oil may be used in the process if necessary. The process provides for deashing the coal prior to hydrogenation and for preventing the coking and swelling of the deashed material. During the treatment with hydrogen, the coal is either mixed with coal low in bituminous material, such as lean coal or active coal, as a diluent or the bituminous constituents which cause the coking and swelling are removed by extraction with solvents. (BLM)

  4. Hydrogen production from hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Docekal, J

    1986-01-01

    Hydrogen is an important feed stock for chemical and petroleum industries, in addition to being considered as the energy carrier of the future. At the present time the feed stock hydrogen is mainly manufactured from hydrocarbons using steam reforming. In steam reforming two processes are employed, the conventional process and PSA (pressure swing adsorption) process. These two processes are described and compared. The results show that the total costs and the maintenance costs are lower for the PSA process, the capital outlay is lower for the conventional process, and the operating costs are similar for the two processes.

  5. The Path to High Q-Factors in Superconducting Accelerating Cavities: Flux Expulsion and Surface Resistance Optimization

    Energy Technology Data Exchange (ETDEWEB)

    Martinello, Martina [Illinois Inst. of Technology, Chicago, IL (United States)

    2016-12-01

    Accelerating cavities are devices resonating in the radio-frequency (RF) range used to accelerate charged particles in accelerators. Superconducting accelerating cavities are made out of niobium and operate at the liquid helium temperature. Even if superconducting, these resonating structures have some RF driven surface resistance that causes power dissipation. In order to decrease as much as possible the power losses, the cavity quality factor must be increased by decreasing the surface resistance. In this dissertation, the RF surface resistance is analyzed for a large variety of cavities made with different state-of-the-art surface treatments, with the goal of finding the surface treatment capable to return the highest Q-factor values in a cryomodule-like environment. This study analyzes not only the superconducting properties described by the BCS surface resistance, which is the contribution that takes into account dissipation due to quasi-particle excitations, but also the increasing of the surface resistance due to trapped flux. When cavities are cooled down below their critical temperature inside a cryomodule, there is always some remnant magnetic field that may be trapped increasing the global RF surface resistance. This thesis also analyzes how the fraction of external magnetic field, which is actually trapped in the cavity during the cooldown, can be minimized. This study is performed on an elliptical single-cell horizontally cooled cavity, resembling the geometry of cavities cooled in accelerator cryomodules. The horizontal cooldown study reveals that, as in case of the vertical cooldown, when the cooling is performed fast, large thermal gradients are created along the cavity helping magnetic flux expulsion. However, for this geometry the complete magnetic flux expulsion from the cavity equator is more difficult to achieve. This becomes even more challenging in presence of orthogonal magnetic field, that is easily trapped on top of the cavity equator

  6. The path to high Q-factors in superconducting accelerating cavities: Flux expulsion and surface resistance optimization

    Science.gov (United States)

    Martinello, Martina

    Accelerating cavities are devices resonating in the radio-frequency (RF) range used to accelerate charged particles in accelerators. Superconducting accelerating cavities are made out of niobium and operate at the liquid helium temperature. Even if superconducting, these resonating structures have some RF driven surface resistance that causes power dissipation. In order to decrease as much as possible the power losses, the cavity quality factor must be increased by decreasing the surface resistance. In this dissertation, the RF surface resistance is analyzed for a large variety of cavities made with different state-of-the-art surface treatments, with the goal of finding the surface treatment capable to return the highest Q-factor values in a cryomodule-like environment. This study analyzes not only the superconducting properties described by the BCS surface resistance, which is the contribution that takes into account dissipation due to quasi-particle excitations, but also the increasing of the surface resistance due to trapped flux. When cavities are cooled down below their critical temperature inside a cryomodule, there is always some remnant magnetic field that may be trapped increasing the global RF surface resistance. This thesis also analyzes how the fraction of external magnetic field, which is actually trapped in the cavity during the cooldown, can be minimized. This study is performed on an elliptical single-cell horizontally cooled cavity, resembling the geometry of cavities cooled in accelerator cryomodules. The horizontal cooldown study reveals that, as in case of the vertical cooldown, when the cooling is performed fast, large thermal gradients are created along the cavity helping magnetic flux expulsion. However, for this geometry the complete magnetic flux expulsion from the cavity equator is more difficult to achieve. This becomes even more challenging in presence of orthogonal magnetic field, that is easily trapped on top of the cavity equator

  7. AD1995: NW Europe's hydrocarbon industry

    International Nuclear Information System (INIS)

    Glennie, K.; Hurst, A.

    1996-01-01

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

  8. Modelling the petroleum generation and migration of the third member of the Shahejie Formation (Es3) in the Banqiao Depression of Bohai Bay Basin, Eastern China

    Science.gov (United States)

    Guo, Xiaowen; He, Sheng; Liu, Keyu; Shi, Zhongsheng; Bachir, Sani

    2011-01-01

    The mudstones in the third member of the Shahejie Formation (Es3) are the primary source rocks in the Banqiao Depression of Bohai Bay Basin. They are rich in organic matter with Total Organic Carbon (TOC) content up to 3.5%. The sandstones in the Es3 member are the deepest proven hydrocarbon reservoir rocks with measured porosity and permeability values ranging from 3.6% to 32.4% and from 0.01 md to 3283.7 md, respectively. One, two and three-dimensional basin modelling studies were performed to analyse the petroleum generation and migration history of the Es3 member in the Banqiao Depression based on the reconstruction of the burial, thermal and maturity history in order to evaluate the remaining potential of this petroleum province. The modelling results are calibrated with measured vitrinite reflectance ( R o), borehole temperatures and some drilling results of 63 wells in the study area. Calibration of the model with thermal maturity and borehole temperature data indicates that the present-day heat flow in the Banqiao Depression varies from 59.8 mW/m 2 to 61.7 mW/m 2 and the paleo-heat flow increased from 65 Ma to 50.4 Ma, reached a peak heat-flow values of approximately 75 mW/m 2 at 50.4 Ma and then decreased exponentially from 50.4 Ma to present-day. The source rocks of the Es3 member are presently in a stage of oil and condensate generation with maturity from 0.5% to 1.8% R o and had maturity from 0.5% to 1.25% R o at the end of the Dongying Formation (Ed) deposition (26 Ma). Oil generation (0.5% R o) in the Es3 member began from about 37 Ma to 34 Ma and the peak hydrocarbon generation (1.0% R o) occurred approximately from 30 Ma to 15 Ma. The modelled hydrocarbon expulsion evolution suggested that the timing of hydrocarbon expulsion from the Es3 member source rocks began from 31 Ma to 10 Ma with the peak hydrocarbon expulsion shortly after 26 Ma. Secondary petroleum migration pathways in the Es3 member of the Banqiao Depression are modelled based on the

  9. Determination of polynuclear hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Lodge, Jr, J P

    1963-01-01

    At the present time, the method of choice for the determination of polynuclear hydrocarbons appears to be the following, (a) extraction of the benzene-soluble fraction from the gross collected particulate matter, (b) one pass through a chromatographic column of partially deactivated alumina, (c) spectral examination of the fractions and (d) the application of appropriate chemical tests as indicated by the previous step. Using this method, the presence of pyrene, fluoranthene, one of the benzofluorenes, chrysens, benz(a)anthracene, benzo(a)pyrene, benzo(e)pyrene, benzo(k)fluoranthene, anthanthrene, and coronene was demonstrated in the air of numerous American cities, and benzo(a)pyrene was measured at some 130 sites. Invaluable as such accurate determinations may be for research purposes, they are still too costly and time-consuming for routine survey purposes. While studies on the subject are by no means complete, they indicate the validity of piperonal chloride test as a general index of polycyclic hydrocarbons. This procedure is described in this paper. 7 references.

  10. Steam hydrocarbon cracking and reforming

    NARCIS (Netherlands)

    Golombok, M.

    2004-01-01

    Many industrial chemical processes are taught as distinct contrasting reactions when in fact the unifying comparisons are greater than the contrasts. We examine steam hydrocarbon reforming and steam hydrocarbon cracking as an example of two processes that operate under different chemical reactivity

  11. Complete Expulsion of Testicular Prosthesis via the Scrotum: A Case-Based Review of the Preventive Surgical Strategies

    Directory of Open Access Journals (Sweden)

    Jack Donati-Bourne

    2015-01-01

    Full Text Available Testicular prostheses are regularly used in urological surgery and are important for postoperative psychological well-being in many patients undergoing orchiectomy. One of the recognised complications of this procedure is graft extrusion, which can result in significant morbidity for patients and require operative reintervention. Whilst most cases of extrusion involve upward graft migration to the external inguinal ring or direct displacement through the scrotal skin, we present an unusual case of complete expulsion of testicular implant three weeks postoperatively through a previously healthy scrotum. During surgical insertion of testicular prostheses, the urological surgeon must carefully consider the different surgical strategies at each step of the operation to prevent future extrusion of the graft. A stepwise review of the preventive surgical strategies to reduce the risk of graft extrusion encompasses the choice of optimal surgical incision, the technique of dissection to create the receiving anatomical pouch, the method of fixation of the implant within the receiving hemiscrotum, and the adoption of good postoperative care measures in line with the principles of sound scrotal surgery.

  12. Simulation of enhanced in-situ biorestoration of petroleum hydrocarbons

    International Nuclear Information System (INIS)

    Borden, R.C.

    1991-01-01

    This paper discusses a general mathematical model being developed to aid in the design and analysis of projects for the enhanced aerobic bioremediation of petroleum-contaminated aquifers. Development of the enhanced biotransformation model is proceeding in three steps: development of an abiotic hydrocarbon dissolution model; coupling the dissolution model with existing equations for simulating aerobic biodegradation; and comparison with laboratory data. The model assumes that the residual hydrocarbon is distributed between two fractions, a fast fraction in equilibrium with the aqueous phase and a slow fraction in which mass transfer is limited. Overall, the model provides an excellent fit to the experimental data and requires a minimum of input parameters

  13. Technical evaluation of the in situ vitrification melt expulsion at the Oak Ridge National Laboratory on April 21, 1996, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    1996-08-01

    On April 21, 1996, at 6:12 p.m., approximately 20 tons of molten glass were expelled from a 216-ton body of molten (approximately 1600 degrees C) radioactively contaminated soil (containing 2.4 Ci of 137 Cs) at a field site at the Oak Ridge National Laboratory in Oak Ridge, Tennessee. The melt expulsion was caused by pressurized steam venting rapidly through, rather than by the desired path around, the molten body. During the previous 17 days, an old seepage pit was undergoing in situ vitrification (ISV) to convert it from porous, leachable soil into a monolithic, impermeable vitreous waste form. Approximately 2 MW of electrical power was being delivered to the molten body, which was contained in the ground and covered with a stainless steel hood maintained under negative pressure to collect, filter, scrub, and monitor off-gas. Off-gas into the hood was rapidly heated by the melt expulsion from a typical operating temperature of 250 degrees C to over 1000 degrees C with an associated surge of pressure sufficient to lift the 15,000-lb hood approximately 12 in. off the ground. A small pool of molten glass was able to flow up to 3 ft outside the hood while it was raised off the ground. The escaping hot off-gas and molten glass ignited several small fires in combustible components near or attached to the external hood frame (e.g, wire insulation, plastic hose, fiberglass trays). Fire department personnel responded to the emergency notification within minutes but were not needed because the small fires self-extinguished within an hour. Four project personnel were performing tasks at the site at the time of the melt expulsion; none were injured or contaminated during the melt expulsion incident. Air samples taken from the hood perimeter near the small fires failed to detect any airborne contamination

  14. Saturated versus unsaturated hydrocarbon interactions with carbon nanostructures

    Directory of Open Access Journals (Sweden)

    Deivasigamani eUmadevi

    2014-09-01

    Full Text Available The interactions of various acyclic and cyclic hydrocarbons in both saturated and unsaturated forms with the carbon nanostructures (CNSs have been explored by using density functional theory (DFT calculations. Model systems representing armchair and zigzag carbon nanotubes (CNTs and graphene have been considered to investigate the effect of chirality and curvature of the CNSs towards these interactions. Results of this study reveal contrasting binding nature of the acyclic and cyclic hydrocarbons towards CNSs. While the saturated molecules show stronger binding affinity in acyclic hydrocarbons; the unsaturated molecules exhibit higher binding affinity in cyclic hydrocarbons. In addition, acyclic hydrocarbons exhibit stronger binding affinity towards the CNSs when compared to their corresponding cyclic counterparts. The computed results excellently corroborate the experimental observations. The interaction of hydrocarbons with graphene is more favourable when compared with CNTs. Bader’s theory of atoms in molecules has been invoked to characterize the noncovalent interactions of saturated and unsaturated hydrocarbons. Our results are expected to provide useful insights towards the development of rational strategies for designing complexes with desired noncovalent interaction involving CNSs.

  15. Left ventricle function in patients with ischemic cardiopathy: determination of the expulsion fraction of the left ventricle with gated-SPECT. Experience in the CMN 20 de Noviembre ISSSTE

    International Nuclear Information System (INIS)

    Mendoza, L.; Puente, A.; Hernandez, T.; Jimenez, L.

    2007-01-01

    The objective of this work is to correlate the expulsion fraction of the left ventricle (FEVI) obtained by means of g-SPECT and other diagnostic methods: ECO 2D and ventriculography for heart catheterization (CTT). (Author)

  16. When to stop pushing: effects of duration of second-stage expulsion efforts on maternal and neonatal outcomes in nulliparous women with epidural analgesia.

    Science.gov (United States)

    Le Ray, Camille; Audibert, François; Goffinet, François; Fraser, William

    2009-10-01

    The purpose of this study was to assess the influence of the duration of active second-stage labor on maternal and neonatal outcomes. Secondary analysis of the Pushing Early Or Pushing Late with Epidural trial that included 1862 nulliparous women with epidural analgesia who were in the second stage of labor. According to duration of active second-stage labor, we estimated the proportion of spontaneous vaginal deliveries (SVD) with a newborn infant without signs of asphyxia (5-minute Apgar score > or =7 and arterial pH >7.10). We also analyzed maternal and neonatal outcomes according to the duration of expulsive efforts. Relative to the first hour of expulsive efforts, the chances of a SVD of a newborn infant without signs of asphyxia decreased significantly every hour (1- to 2-hour adjusted odds ratio, 0.4; 95% confidence interval [CI], 0.3-0.6; 2- to 3-hour adjusted odds ratio, 0.1; 95% CI, 0.09-0.2; >3-hour adjusted odds ratio, 0.03; 95% CI, 0.02-0.05). The risk of postpartum hemorrhage and intrapartum fever increased significantly after 2 hours of pushing. Faced with a decreasing probability of SVD and increased maternal risk of morbidity after 2 hours, we raise the question as to whether expulsive efforts should be continued after this time.

  17. Canada's hydrocarbon processing evolution

    International Nuclear Information System (INIS)

    Wise, T.H.; Horton, R.

    2000-01-01

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

  18. Hydrogenating gaseous hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Nicolardot, P L.F.

    1930-08-06

    Gaseous hydrocarbons obtained by the destructive distillation of carbonaceous materials are simultaneously desulfurized and hydrogenated by passing them at 350 to 500/sup 0/C, mixed with carbon monoxide and water vapor over lime mixed with metallic oxides present in sufficient amount to absorb the carbon dioxide as it is formed. Oxides of iron, copper, silver, cobalt, and metals of the rare earths may be used and are mixed with the lime to form a filling material of small pieces filling the reaction vessel which may have walls metallized with copper and zinc dust. The products are condensed and fixed with absorbents, e.g. oils, activated carbon, silica gels. The metallic masses may be regenerated by a hot air stream and by heating in inert gases.

  19. Treating hydrocarbon oils

    Energy Technology Data Exchange (ETDEWEB)

    Scott, R; MacIvor, W

    1869-09-01

    The treatment of hydrocarbon oils, such as coal or shale oils, paraffin oils, and petroleum, either in the crude or more or less refined state has the object of reducing the specific gravity and otherwise improving the qualities of such oils. The oil to be treated is put into any ordinary still and distilled. The vapor escaping during the distillation is passed through one or more heating vessels or chambers and exposed to the heat necessary to produce the change. The heating vessels or chambers may be made of metal, clay, or any other material adapted to endure heat, and they may be made of any desired form, or they may be constituted of a coil of metal pipes or a series of tubes such as are used for heating air for blast furnaces.

  20. Controls on methane expulsion during melting of natural gas hydrate systems. Topic area 2

    Energy Technology Data Exchange (ETDEWEB)

    Flemings, Peter [Univ. of Texas, Austin, TX (United States)

    2016-01-14

    1.1. Project Goal The project goal is to predict, given characteristic climate-induced temperature change scenarios, the conditions under which gas will be expelled from existing accumulations of gas hydrate into the shallow ocean or directly to the atmosphere. When those conditions are met, the fraction of the gas accumulation that escapes and the rate of escape shall be quantified. The predictions shall be applicable in Arctic regions and in gas hydrate systems at the up dip limit of the stability zone on continental margins. The behavior shall be explored in response to two warming scenarios: longer term change due to sea level rise (e.g. 20 thousand years) and shorter term due to atmospheric warming by anthropogenic forcing (decadal time scale). 1.2. Project Objectives During the first budget period, the objectives are to review and categorize the stability state of existing well-studied hydrate reservoirs, develop conceptual and numerical models of the melting process, and to design and conduct laboratory experiments that dissociate methane hydrate in a model sediment column by systematically controlling the temperature profile along the column. The final objective of the first budget period shall be to validate the models against the experiments. In the second budget period, the objectives are to develop a model of gas flow into sediment in which hydrate is thermodynamically stable, and conduct laboratory experiments of this process to validate the model. The developed models shall be used to quantify the rate and volume of gas that escapes from dissociating hydrate accumulations. In addition, specific scaled simulations characteristic of Arctic regions and regions near the stability limit at continental margins shall be performed. 1.3. Project Background and Rationale The central hypothesis proposed is that hydrate melting (dissociation) due to climate change generates free gas that can, under certain conditions, propagate through the gas hydrate stability

  1. Characterization of a nose-only inhalation exposure system for hydrocarbon mixtures and jet fuels.

    Science.gov (United States)

    Martin, Sheppard A; Tremblay, Raphael T; Brunson, Kristyn F; Kendrick, Christine; Fisher, Jeffrey W

    2010-04-01

    A directed-flow nose-only inhalation exposure system was constructed to support development of physiologically based pharmacokinetic (PBPK) models for complex hydrocarbon mixtures, such as jet fuels. Due to the complex nature of the aerosol and vapor-phase hydrocarbon exposures, care was taken to investigate the chamber hydrocarbon stability, vapor and aerosol droplet compositions, and droplet size distribution. Two-generation systems for aerosolizing fuel and hydrocarbons were compared and characterized for use with either jet fuels or a simple mixture of eight hydrocarbons. Total hydrocarbon concentration was monitored via online gas chromatography (GC). Aerosol/vapor (A/V) ratios, and total and individual hydrocarbon concentrations, were determined using adsorbent tubes analyzed by thermal desorption-gas chromatography-mass spectrometry (TDS-GC-MS). Droplet size distribution was assessed via seven-stage cascade impactor. Droplet mass median aerodynamic diameter (MMAD) was between 1 and 3 mum, depending on the generator and mixture utilized. A/V hydrocarbon concentrations ranged from approximately 200 to 1300 mg/m(3), with between 20% and 80% aerosol content, depending on the mixture. The aerosolized hydrocarbon mixtures remained stable during the 4-h exposure periods, with coefficients of variation (CV) of less than 10% for the total hydrocarbon concentrations. There was greater variability in the measurement of individual hydrocarbons in the A-V phase. In conclusion, modern analytical chemistry instruments allow for improved descriptions of inhalation exposures of rodents to aerosolized fuel.

  2. Terapia Expulsiva Medicamentosa na Litíase Ureteral: Revisão de Literatura/ Medicamental Expulsive Therapy in Ureteral Lithiasis: Literature Review

    Directory of Open Access Journals (Sweden)

    Kenji Maeda Missima

    2014-06-01

    Full Text Available A terapia expulsiva medicamentosa na litíase ureteral tem ganhado importante espaço na prática clínica, visto que é um método não invasivo e de grande eficácia. Como se trata de uma afecção comum, de alta incidência e custo, a terapia expulsiva possibilita um manejo clínico menos dispendioso e invasivo, quando comparada a procedimentos intervencionistas. Há consenso na literatura que a terapia expulsiva medicamentosa é efetiva e deve ser utilizada em cálculos com cerca de 5 milímetros de diâmetro, visto que as drogas utilizadas aumentam a taxa e diminuem o tempo de expulsão, além de diminuir a dor e o número de internações. O tamanho e localização do cálculo são de extrema relevância para que se possa considerar o manejo conservador. As drogas que obtém as melhores taxas expulsivas são os bloqueadores dos receptores alfa-adrenérgicos e os bloqueadores dos canais de cálcio. Analgésicos também são utilizados para o alívio da dor e o uso de corticoides ainda é questionado. Medicamental expulsive therapy for ureteral stones has gained important place in clinical practice, because it is a noninvasive and highly effective method. As it is a common disorder with high incidence and cost, expulsive therapy provides a less costly and invasive clinical management when compared to interventional procedures. There is a consensus that the medicamental expulsive therapy is effective and should be used in calculations with about 5 millimeters in diameter, since the drugs used increase rate and decrease the time of expulsion, in addition to reducing the pain and the number of hospitalizations. The size and location of the calculi are very important for it to be considered conservative management. The drugs that get the best expulsive rates are alpha - adrenergic receptor blockers and calcium channel blockers. Analgesics are also used for pain relief and the use of corticosteroids is still questioned.

  3. High Pressure Preignition Chemistry of Hydrocarbons and Hydrocarbon Mixtures

    National Research Council Canada - National Science Library

    Cernansky, N.P

    1998-01-01

    .... The research program entailed mechanistic studies examining the oxidation chemistry of single-component hydrocarbons and ignition studies examining the overall ignition of pure single component fuels and fuel blends...

  4. Preliminary Experimental Examination Of Controls On Methane Expulsion During Melting Of Natural Gas Hydrate Systems

    Science.gov (United States)

    Kneafsey, T. J.; Flemings, P. B.; Bryant, S. L.; You, K.; Polito, P. J.

    2013-12-01

    Global climate change will cause warming of the oceans and land. This will affect the occurrence, behavior, and location of subseafloor and subterranean methane hydrate deposits. We suggest that in many natural systems local salinity, elevated by hydrate formation or freshened by hydrate dissociation, may control gas transport through the hydrate stability zone. We are performing experiments and modeling the experiments to explore this behavior for different warming scenarios. Initially, we are exploring hydrate association/dissociation in saline systems with constant water mass. We compare experiments run with saline (3.5 wt. %) water vs. distilled water in a sand mixture at an initial water saturation of ~0.5. We increase the pore fluid (methane) pressure to 1050 psig. We then stepwise cool the sample into the hydrate stability field (~3 degrees C), allowing methane gas to enter as hydrate forms. We measure resistivity and the mass of methane consumed. We are currently running these experiments and we predict our results from equilibrium thermodynamics. In the fresh water case, the modeled final hydrate saturation is 63% and all water is consumed. In the saline case, the modeled final hydrate saturation is 47%, the salinity is 12.4 wt. %, and final water saturation is 13%. The fresh water system is water-limited: all the water is converted to hydrate. In the saline system, pore water salinity is elevated and salt is excluded from the hydrate structure during hydrate formation until the salinity drives the system to three phase equilibrium (liquid, gas, hydrate) and no further hydrate forms. In our laboratory we can impose temperature gradients within the column, and we will use this to investigate equilibrium conditions in large samples subjected to temperature gradients and changing temperature. In these tests, we will quantify the hydrate saturation and salinity over our meter-long sample using spatially distributed temperature sensors, spatially distributed

  5. CSDA range, stopping power and mean penetration depth energy relationships in some hydrocarbons and biologic materials for 10 eV to 100 MeV with the modified Rohrlich-Carlson model

    Energy Technology Data Exchange (ETDEWEB)

    Guemues, Hasan [Ondokuz Mayis University, Department of Physics, Faculty of Sciences and Arts, Samsun (Turkey); Bentabet, Abdelouahab [Bordj Bou Arreridj University, LCVRN, SNVSTU Faculty, El Anasser (Algeria)

    2017-05-15

    In this study, for some hydrocarbons and biological compounds, stopping power formula are presented, being valid for low and intermediate electron energies. In addition, calculation of the continuous slowing down approximation range (CSDA range) from the stopping power is also made. Calculation of the CSDA range for some hydrocarbons: C{sub 2}H{sub 6} (ethane), C{sub 4}H{sub 10} (butane), C{sub 6}H{sub 14} (hexane) C{sub 8}H{sub 18} (octane), C{sub 5}H{sub 5}N{sub 5} (adenine) and C{sub 5}H{sub 5}N{sub 5}O (guanine) have been introduced for incident electrons in the energy range 30 eV to 1 MeV. The range of electrons has been calculated within the continuous slowing down approximation (CSDA) using modified Rohrlich and Carlson formula of stopping power. Besides, we have calculated the mean penetration depths using a spherical geometric model developed by Bentabet (Vacuum 86:1855-1859, 35). The results have been compared with the other theoretical results, Monte Carlo code such as PENELOPE predictions and semi-empirical results. The calculated results of CSDA ranges for electrons in the energy range from 20 eV to 100 MeV are found to be in good agreement to within 10% with available date. (orig.)

  6. Structures of BmrR-Drug Complexes Reveal a Rigid Multidrug Binding Pocket And Transcription Activation Through Tyrosine Expulsion

    Energy Technology Data Exchange (ETDEWEB)

    Newberry, K.J.; Huffman, J.L.; Miller, M.C.; Vazquez-Laslop, N.; Neyfakh, A.A.; Brennan, R.G.

    2009-05-22

    BmrR is a member of the MerR family and a multidrug binding transcription factor that up-regulates the expression of the bmr multidrug efflux transporter gene in response to myriad lipophilic cationic compounds. The structural mechanism by which BmrR binds these chemically and structurally different drugs and subsequently activates transcription is poorly understood. Here, we describe the crystal structures of BmrR bound to rhodamine 6G (R6G) or berberine (Ber) and cognate DNA. These structures reveal each drug stacks against multiple aromatic residues with their positive charges most proximal to the carboxylate group of Glu-253 and that, unlike other multidrug binding pockets, that of BmrR is rigid. Substitution of Glu-253 with either alanine (E253A) or glutamine (E253Q) results in unpredictable binding affinities for R6G, Ber, and tetraphenylphosphonium. Moreover, these drug binding studies reveal that the negative charge of Glu-253 is not important for high affinity binding to Ber and tetraphenylphosphonium but plays a more significant, but unpredictable, role in R6G binding. In vitro transcription data show that E253A and E253Q are constitutively active, and structures of the drug-free E253A-DNA and E253Q-DNA complexes support a transcription activation mechanism requiring the expulsion of Tyr-152 from the multidrug binding pocket. In sum, these data delineate the mechanism by which BmrR binds lipophilic, monovalent cationic compounds and suggest the importance of the redundant negative electrostatic nature of this rigid drug binding pocket that can be used to discriminate against molecules that are not substrates of the Bmr multidrug efflux pump.

  7. Growth of hydrocarbon utilizing microorganisms

    Digital Repository Service at National Institute of Oceanography (India)

    Bhosle, N.B.; Mavinkurve, S.

    Two isolates from marine mud having broad spectrum hydrocarbon utilizing profile were identified as Arthrobacter simplex and Candida tropicalis.Both the organisms grew exponentially on crude oil. The cell yield of the organisms was influenced...

  8. Process for treating hydrocarbons, etc

    Energy Technology Data Exchange (ETDEWEB)

    1933-09-15

    A process is described for treating simultaneously bituminous substances and hydrocarbon oils for the production of low-boiling hydrocarbons and volatilization of the bituminous substances, characterized by the fact that it consists of heating a current of charge constituted by a mixture of the bituminous substances and hydrocarbon oils, to a high temperature, passing the heated current into a zone of extended reaction where the vapors are separated from the liquid or solid residue to favor transformation of the liquid hydrocarbons and volatilization of the bituminous substances, owing to the utilization of a heating agent carried to a high temperature being brought in contact with the heated charge in order to communicate its heat to the charge, while this later presents itself as relatively fine pellet or in the condition of distinct particles, particularly separated from one another.

  9. Predicting hydrocarbon release from soil

    International Nuclear Information System (INIS)

    Poppendieck, D.; Loehr, R.C.

    2002-01-01

    '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

  10. Hydrodynamics of material removal by melt expulsion: Perspectives of laser cutting and drilling

    Science.gov (United States)

    Poprawe, Reinhart; Schulz, Wolfgang; Schmitt, Robert

    With the introduction of fiber-guided radiation at 1 μ wavelength emitting in the milti-kW range at better beam quality than CO2-lasers the most established application in laser processing, namely laser fusion cutting, came back into the industrial and scientific focus. Laser sources with extraordinary optical and economical properties - disk and fiber lasers - in a stormy way enter the market of cutting machines so far reserved for the 10 μ radiation source and led to a volatile situation. The new laser sources can already address a market-relevant class of applications, namely, fusion cutting of steel up to a sheet thickness of 2 mm with pronounced advantages in productivity. However, there is a significant lack of cut quality for larger sheet thickness. The main reason for the drawback and its physical background are given. With the availability of cutting machines with 1 μ fiber-guided radiation the race for the worldwide market regarding the larger sheet thickness is opened and the priority issues to improve the cut quality are related to the three levels: wavelength, beam delivery and the application stage of the machine. The stability model called QuCut is presented which for the first time allows to analyze stability of cutting with fiber-guided radiation. Experimental ripple patterns and ripple spectra resolved with respect to the cutting depth are well reproduced by the new stability model. A number of different experimental methods towards an improved understanding of the dynamics in laser drilling are developed, however, there are gaps related to in-situ observation which is obscured by the hole walls. There are four novel experimental methods resolving the dynamics from a μms-down to a ns-time scale having a spatial resolution with respect to transient drilling depth on the μm scale. As result, the different mechanisms contributing to recast formation and dynamical features of drilling are revealed in more detail. In particular, the action of

  11. Hydrocarbon removal with constructed wetlands

    OpenAIRE

    Eke, Paul Emeka

    2008-01-01

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

  12. Bioassay of polycyclic aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Van Kirk, E.A.

    1980-08-01

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

  13. Catalytic pyrolysis of hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Vail' eva, N A; Buyanov, R A

    1979-01-01

    Catalytic pyrolysis of petroleum fractions (undecane) was performed with the object of clarifying such questions as the mechanism of action of the catalyst, the concepts of activity and selectivity of the catalyst, the role of transport processes, the temperature ranges and limitations of the catalytic process, the effect of the catalyst on secondary processes, and others. Catalysts such as quartz, MgO, Al/sub 2/O/sub 3/, were used. Analysis of the experimental findings and the fact that the distribution of products is independent of the nature of the surface, demonstrate that the pyrolysis of hydrocarbons in the presence of catalysts is based on the heterogeneous-homogeneous radical-chain mechanism of action, and that the role of the catalysts reduces to increasing the concentration of free radicals. The concept of selectivity cannot be applied to catalysts here, since they do not affect the mechanism of the unfolding of the process of pyrolysis and their role consists solely in initiating the process. In catalytic pyrolysis the concepts of kinetic and diffusive domains of unfolding of the catalytic reaction do not apply, and only the outer surface of the catalyst is engaged, whereas the inner surface merely promotes deletorious secondary processes reducing the selectivity of the process and the activity of the catalyst. 6 references, 2 figures.

  14. HYDROCARBONS RESERVES IN VENEZUELA

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez Cruz, D.J.

    2007-07-01

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

  15. Evaluation of hydrocarbon potential

    International Nuclear Information System (INIS)

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

    1992-01-01

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

  16. Polycyclic Aromatic Hydrocarbons

    Science.gov (United States)

    Salama, Farid

    2010-01-01

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

  17. Syntrophic biodegradation of hydrocarbon contaminants.

    Science.gov (United States)

    Gieg, Lisa M; Fowler, S Jane; Berdugo-Clavijo, Carolina

    2014-06-01

    Anaerobic environments are crucial to global carbon cycling wherein the microbial metabolism of organic matter occurs under a variety of redox conditions. In many anaerobic ecosystems, syntrophy plays a key role wherein microbial species must cooperate, essentially as a single catalytic unit, to metabolize substrates in a mutually beneficial manner. Hydrocarbon-contaminated environments such as groundwater aquifers are typically anaerobic, and often methanogenic. Syntrophic processes are needed to biodegrade hydrocarbons to methane, and recent studies suggest that syntrophic hydrocarbon metabolism can also occur in the presence of electron acceptors. The elucidation of key features of syntrophic processes in defined co-cultures has benefited greatly from advances in 'omics' based tools. Such tools, along with approaches like stable isotope probing, are now being used to monitor carbon flow within an increasing number of hydrocarbon-degrading consortia to pinpoint the key microbial players involved in the degradative pathways. The metagenomic sequencing of hydrocarbon-utilizing consortia should help to further identify key syntrophic features and define microbial interactions in these complex communities. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Production of light hydrocarbons, etc. [from heavy hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    1937-10-07

    A process is given for the production of light hydrocarbons of the gasoline type and, if desired, of the middle-oil type, from liquid or fusible heavy or medium heavy hydrocarbon materials. The process comprises subjecting the said initial materials in the first stage to catalytic hydrofining, separating the lower boiling constituents and the hydrogenating gas from the resulting products and then subjecting the higher boiling constituents in a second stage to a splitting destructive hydrogenation and then recycling substantially the entire reaction mixture obtained in the second stage to the frst stage.

  19. Four-dimensional data coupled to alternating weighted residue constraint quadrilinear decomposition model applied to environmental analysis: Determination of polycyclic aromatic hydrocarbons

    Science.gov (United States)

    Liu, Tingting; Zhang, Ling; Wang, Shutao; Cui, Yaoyao; Wang, Yutian; Liu, Lingfei; Yang, Zhe

    2018-03-01

    Qualitative and quantitative analysis of polycyclic aromatic hydrocarbons (PAHs) was carried out by three-dimensional fluorescence spectroscopy combining with Alternating Weighted Residue Constraint Quadrilinear Decomposition (AWRCQLD). The experimental subjects were acenaphthene (ANA) and naphthalene (NAP). Firstly, in order to solve the redundant information of the three-dimensional fluorescence spectral data, the wavelet transform was used to compress data in preprocessing. Then, the four-dimensional data was constructed by using the excitation-emission fluorescence spectra of different concentration PAHs. The sample data was obtained from three solvents that are methanol, ethanol and Ultra-pure water. The four-dimensional spectral data was analyzed by AWRCQLD, then the recovery rate of PAHs was obtained from the three solvents and compared respectively. On one hand, the results showed that PAHs can be measured more accurately by the high-order data, and the recovery rate was higher. On the other hand, the results presented that AWRCQLD can better reflect the superiority of four-dimensional algorithm than the second-order calibration and other third-order calibration algorithms. The recovery rate of ANA was 96.5% 103.3% and the root mean square error of prediction was 0.04 μgL- 1. The recovery rate of NAP was 96.7% 115.7% and the root mean square error of prediction was 0.06 μgL- 1.

  20. Breakdown of interference rules in azulene, a nonalternant hydrocarbon

    DEFF Research Database (Denmark)

    Xia, Jianlong; Capozzi, Brian; Wei, Sujun

    2014-01-01

    interference characteristics of nonalternant hydrocarbons. As an exemplary case, we show that azulene derivatives that are predicted to exhibit destructive interference based on widely accepted atom-counting models show a significant conductance at low biases. Although simple models to predict the low...

  1. Production of hydrocarbons, especially ethylene

    Energy Technology Data Exchange (ETDEWEB)

    1952-01-17

    The invention has for its object a process for the production of gaseous nonsaturated hydrocarbons, particularly ethylene and aromatic hydrocarbons, by starting with hydrocarbon oils entirely of paraffinic nature or their fractions, which consists in putting the separated products in contact with solid inert material especially with porous nonmetallic inert material or of heavy metals or their alloys, maybe in a finely divided state or in the form, of pieces or chips, at a temperature above 500/sup 0/C, or better between 600 and 700/sup 0/C at a velocity per hour of 0.6 to 3.0, and preferably 0.75 to 1.5 parts per volume of products per each part of space volume of catalyst.

  2. Enrichment of light hydrocarbon mixture

    Science.gov (United States)

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

    2010-08-10

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

  3. Production of hydrocarbons of value

    Energy Technology Data Exchange (ETDEWEB)

    1931-06-16

    A process is described for the production of hydrocarbons of great value by treating with heat and pressure carbonaceous materials such as coals, tars, mineral oils, and products of distillation and transformation of these materials, also for the refining with heat and pressure of mixed liquid hydrocarbons by means of hydrogen gas, preferably in the presence of catalysts, consisting in using as the hydrogenating gas that obtained by gasification of combustible solids after partial or complete cleaning at atmospheric or elevated pressures, by means of solid adsorbents, chemical agents or catalysts, or mixtures of these agents, the hydrocarbons being characterized by strong unsaturation, and the presence of oxygen, sulfur compounds, and oxides of nitrogen.

  4. Process of distilling heavy hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    1929-12-03

    This invention has for its object the distillation of heavy liquid hydrocarbons for the purpose of obtaining lighter hydrocarbons stable and immediately salable for fuels in combustion motors. The process is distinguished by the fact that the heavy hydrocarbon is distilled by means of heating to a temperature in keeping with the nature of the material to be treated up to 350/sup 0/C under pressure or without pressure the distillation being carried out on catalysts containing successively nickel, copper, and iron (3 parts of nickel, 1 part of copper, and 1 part of iron), the vapors produced by this distillation being exposed in turn to the action of catalysts of the same nature and in the same proportion.

  5. Distribution of hydrocarbons released during the 2010 MC252 oil spill in deep offshore waters

    International Nuclear Information System (INIS)

    Spier, Chelsea; Stringfellow, William T.; Hazen, Terry C.; Conrad, Mark

    2013-01-01

    The explosion of the Deepwater Horizon oil platform on April 20th, 2010 resulted in the second largest oil spill in history. The distribution and chemical composition of hydrocarbons within a 45 km radius of the blowout was investigated. All available certified hydrocarbon data were acquired from NOAA and BP. The distribution of hydrocarbons was found to be dispersed over a wider area in subsurface waters than previously predicted or reported. A deepwater hydrocarbon plume predicted by models was verified and additional plumes were identified. Because the samples were not collected systematically, there is still some question about the presence and persistence of an 865 m depth plume predicted by models. Water soluble compounds were extracted from the rising oil in deepwater, and were found at potentially toxic levels outside of areas previously reported to contain hydrocarbons. Application of subsurface dispersants was found to increase hydrocarbon concentration in subsurface waters. - Highlights: ► The hydrocarbon distribution was more widely spread than previously predicted or reported. ► 4 subsurface plumes were identified. ► More soluble compounds were preferentially extracted in the deepwater. ► Percentage of detectable results is a useful data analysis technique. ► Subsurface dispersants application increased hydrocarbons in subsurface waters. - All available certified Deepwater Horizon data was used to determine the spatial, temporal, and chemical distribution of hydrocarbons in subsurface of the Gulf of Mexico.

  6. Polycyclic aromatic hydrocarbons in stellar medium

    Science.gov (United States)

    Rastogi, Shantanu

    2005-06-01

    Polycyclic Aromatic Hydrocarbons (PAHs) are an important com- ponent of the Interstellar Medium (ISM). They are being used as probes for understanding of process and conditions of different astrophysical environments. The understanding of their IR spectra and its variations with PAH size and ionization state is useful in characterizing the ISM. Spectral features of model graphene sheets and also that of smaller PAH molecules are reported. The variation of intensity with charge state of the molecule shows that cations give a better correlation with observations. The relationship between changes in charge distribution with intensity changes upon ionization has been probed.

  7. Preparing valuable hydrocarbons by hydrogenation

    Energy Technology Data Exchange (ETDEWEB)

    Pier, M

    1930-08-22

    A process is described for the preparation of valuable hydrocarbons by treatment of carbonaceous materials, like coal, tars, minerals oils, and their distillation and conversion products, and for refining of liquid hydrocarbon mixture obtained at raised temperature and under pressure, preferably in the presence of catalysts, by the use of hydrogen-containing gases, purified and obtained by distilling solid combustibles, characterized by the purification of the hydrogen-containing gases being accomplished for the purpose of practically complete removal of the oxygen by heating at ordinary or higher pressure in the presence of a catalyst containing silver and oxides of metals of group VI of the periodic system.

  8. Purifying and regenerating hydrocarbon oils

    Energy Technology Data Exchange (ETDEWEB)

    1931-11-19

    Hydrocarbons are freed from sulfur-containing compounds, colloidal asphaltic bodies and unstable unsaturated substances by treatment with a small amount of dilute sulfuric acid and a salt of a trivalent cation, such as ferric chloride or sulfate. Hydrocarbons specified are petroleum, crude benzol, low temperature tars, shale oil or vapor-phase cracked spirit. Motor spirit or lubricating oil distillates are refined and finally distilled. The acid reagent may be regenerated by filtering through sand or asbestos. Used lubricating oils may be treated similarly and after removal of refining agent, the oil is heated with an adsorbent and decolorizing material and then filtered.

  9. Hydrocarbons cocktails of the future

    International Nuclear Information System (INIS)

    Anon.

    2004-01-01

    This publication of the Areva Group, a world nuclear industry leader, provides information on the energy in many domains. This issue deals with the CO 2 pollution exchange, the carbon sinks to compensate the CO 2 , the green coal as an innovative solution, an outsize dam in China, the solar energy progresses in France and the french medicine academy in favor of Nuclear. A special chapter is devoted to the hydrocarbons of the future, artificial chemical combination created from constituents of hydrocarbons and derived from various sources. (A.L.B.)

  10. On the study of petroleum system operation: contribution of a two-dimensional modeling; Contribution a l`etude du fonctionnement des systemes petroliers: apport d`une modelisation bi-dimensionnelle

    Energy Technology Data Exchange (ETDEWEB)

    Burrus, J

    1997-07-10

    The aim of the thesis is to validate concepts used in hydrocarbon generation and migration models; the model considered is the Temispack model developed by IFP, and the validation is based on the investigation of the thermal and hydraulic evolution in various sedimentary basins. It is shown that, in general, the thermal history of sediments is influenced by external processes (sedimentation rates, lithology, climate changes, regional-scale groundwater circulations) which frequently overprint internal processes (variations of crustal/mantle heat flow). It is found that external processes can frequently explain past thermal events that were erroneously attributed to internal causes (tectonic-thermal events). The origin of over-pressures in young basins with high sedimentation rates is shown to be generally related to compaction disequilibrium. Shale permeability values calibrated against overpressure profiles are consistent with experimental constraints. Compaction models predict too-high porosity in over-pressured sediments; this inconsistency is shown to be related to an inadequate definition of the Biot coefficient. In intracratonic basins with low sedimentation rates, diagenesis and fracturing are responsible for the large variability of shale permeability. Hydrocarbon generation models based on Arrhenius kinetics, and kinetic parameters calibrated on Rock Eval pyrolysis experiments are shown to be consistent with observations. Hydrocarbon expulsion and migration can be approximated by a multiphase Darcy equation using pseudo relative permeabilities. Migration pathways are shown to be very sensitive to the stratigraphic organization of basins. The volume 1 presents a bibliographical review, the Temispack model, and the geodynamics of a passive-type margin, the Gulf of Lion

  11. Phase equilibria at low temperature for light hydrocarbons-methanol-water-acid gases mixtures: measurements and modelling; Equilibres de phases a basse temperature de systemes complexes CO{sub 2} - hydrocarbures legers - methanol - eau: mesures et modelisation

    Energy Technology Data Exchange (ETDEWEB)

    Ruffine, L.

    2005-10-15

    The need to develop and improve natural gas treatment processes is real. The petroleum industry usually uses separation processes which require phase equilibrium phenomena. Yet, the complexity of the phase equilibria involved results in a lack of data, which in turn limits the development of thermodynamic models. The first part of this work is devoted to experimental investigations for systems containing light hydrocarbons, methanol, water and acid gases. We present a new apparatus that was developed to measure vapor-liquid and vapor-liquid-liquid equilibria. It allowed us to obtain new phase composition data for the methanol-ethane binary system and different mixtures, and also to determine a part of the three phases equilibrium envelope of the same systems. In the second part of this work, we have developed a thermodynamic model based on the CPA equation of state. This choice may be justified by the presence of associating components like methanol, hydrogen sulfide and water in the systems. Such model is necessary for the design of gas treatment plants. Our model provides good results for phase equilibrium calculations for binaries systems without binary interaction parameter in many cases, and describes correctly the vapour-liquid and vapor-liquid-liquid equilibria for complex mixtures. (author)

  12. BIOREMEDIATION OF A PETROLEUM-HYDROCARBON

    African Journals Online (AJOL)

    ES OBE

    under field conditions in the bioremediation of a petroleum- hydrocarbon polluted ... an accelerated biodegradation of petroleum hydrocarbons in a polluted agricultural soil ..... 12) Jackson, M.L. Soil chemical analysis. ... biological assay. 3 rd.

  13. Total Petroleum Hydrocarbons (TPH): ToxFAQs

    Science.gov (United States)

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

  14. Temperature-dependent kinetics of charge transfer, hydrogen-atom transfer, and hydrogen-atom expulsion in the reaction of CO+ with CH4 and CD4.

    Science.gov (United States)

    Melko, Joshua J; Ard, Shaun G; Johnson, Ryan S; Shuman, Nicholas S; Guo, Hua; Viggiano, Albert A

    2014-09-18

    We have determined the rate constants and branching ratios for the reactions of CO(+) with CH4 and CD4 in a variable-temperature selected ion flow tube. We find that the rate constants are collisional for all temperatures measured (193-700 K for CH4 and 193-500 K for CD4). For the CH4 reaction, three product channels are identified, which include charge transfer (CH4(+) + CO), H-atom transfer (HCO(+) + CH3), and H-atom expulsion (CH3CO(+) + H). H-atom transfer is slightly preferred to charge transfer at low temperature, with the charge-transfer product increasing in contribution as the temperature is increased (H-atom expulsion is a minor product for all temperatures). Analogous products are identified for the CD4 reaction. Density functional calculations on the CO(+) + CH4 reaction were also conducted, revealing that the relative temperature dependences of the charge-transfer and H-atom transfer pathways are consistent with an initial charge transfer followed by proton transfer.

  15. Expulsion d’etrangers et Convention européenne des droits de l’homme Le risque de mauvais traitements dans l’Etat de destinatio

    Directory of Open Access Journals (Sweden)

    Syméon Karagiannis

    2010-12-01

    Full Text Available The right of States, for a variety of reasons, to expel aliens hasnever been disputed by the European Court of Human Rights insofar as aState party to the European Convention on Human Rights continues, quite naturally, to exercise its sovereignty over its territory. However, this right has to be reconciled with the obligation of States parties to the European Convention on Human Rights not to expose aliens and, more generally, persons under their jurisdictionto a risk of violation of the provisions of the Convention. Yet, guaranteeing that no human right recognized as such by the Convention be violated in case of expulsion is too heavy a task for States to assume. Imposing such an obligation would end up in invalidatingthe sovereign right of States to expel aliens. The Court ofStrasbourg retains primarily the risk of Article 3 of the Convention being violated in expulsion cases, a provision according to which inhuman or degrading punishments or treatments and, of course, acts of torture are strictly prohibited. The Court’s case-law, abundant aswell as rich in nuances, results in rather a thorough examination of the human rights situation in any country towards which a alien will be (or has already been expelled.

  16. Scaling relationships for adsorption energies of C2 hydrocarbons on transition metal surfaces

    DEFF Research Database (Denmark)

    Jones, Glenn; Studt, Felix; Abild-Pedersen, Frank

    2011-01-01

    for AHx-type adsorbates to unsaturated hydrocarbons and establishes a coherent simplified description of saturated as well as unsaturated hydrocarbons adsorbed on transition metal surfaces. A number of potential applications are discussed. We apply the model to the dehydrogenation of ethane over pure...

  17. Effective viscosity of confined hydrocarbons

    DEFF Research Database (Denmark)

    Sivebæk, Ion Marius; Samoilov, V.N.; Persson, B.N.J.

    2012-01-01

    We present molecular dynamics friction calculations for confined hydrocarbon films with molecular lengths from 20 to 1400 carbon atoms. We find that the logarithm of the effective viscosity ηeff for nanometer-thin films depends linearly on the logarithm of the shear rate: log ηeff=C-nlog γ̇, where...

  18. THE STRUCTURE, ORIGIN, AND EVOLUTION OF INTERSTELLAR HYDROCARBON GRAINS

    Energy Technology Data Exchange (ETDEWEB)

    Chiar, J. E.; Ricca, A. [SETI Institute, Carl Sagan Center, 189 Bernardo Avenue, Mountain View, CA 94043 (United States); Tielens, A. G. G. M. [Leiden Observatory, P.O. Box 9513, NL-2300 RA Leiden (Netherlands); Adamson, A. J., E-mail: jchiar@seti.org, E-mail: Alessandra.Ricca@1.nasa.gov, E-mail: tielens@strw.leidenuniv.nl, E-mail: aadamson@gemini.edu [Gemini Observatory, Northern Operations Center, 670 North A' ohoku Place, Hilo, HI 96729 (United States)

    2013-06-10

    Many materials have been considered for the carrier of the hydrocarbon absorption bands observed in the diffuse interstellar medium (ISM). In order to refine the model for ISM hydrocarbon grains, we analyze the observed aromatic (3.28, 6.2 {mu}m) and aliphatic (3.4 {mu}m) hydrocarbon absorption features in the diffuse ISM along the line of sight toward the Galactic center Quintuplet Cluster. Observationally, sp {sup 2} bonds can be measured in astronomical spectra using the 6.2 {mu}m CC aromatic stretch feature, whereas the 3.4 {mu}m aliphatic feature can be used to quantify the fraction of sp {sup 3} bonds. The fractional abundance of these components allows us to place the Galactic diffuse ISM hydrocarbons on a ternary phase diagram. We conclude that the Galactic hydrocarbon dust has, on average, a low H/C ratio and sp {sup 3} content and is highly aromatic. We have placed the results of our analysis within the context of the evolution of carbon dust in the ISM. We argue that interstellar carbon dust consists of a large core of aromatic carbon surrounded by a thin mantle of hydrogenated amorphous carbon (a-C:H), a structure that is a natural consequence of the processing of stardust grains in the ISM.

  19. THE STRUCTURE, ORIGIN, AND EVOLUTION OF INTERSTELLAR HYDROCARBON GRAINS

    International Nuclear Information System (INIS)

    Chiar, J. E.; Ricca, A.; Tielens, A. G. G. M.; Adamson, A. J.

    2013-01-01

    Many materials have been considered for the carrier of the hydrocarbon absorption bands observed in the diffuse interstellar medium (ISM). In order to refine the model for ISM hydrocarbon grains, we analyze the observed aromatic (3.28, 6.2 μm) and aliphatic (3.4 μm) hydrocarbon absorption features in the diffuse ISM along the line of sight toward the Galactic center Quintuplet Cluster. Observationally, sp 2 bonds can be measured in astronomical spectra using the 6.2 μm CC aromatic stretch feature, whereas the 3.4 μm aliphatic feature can be used to quantify the fraction of sp 3 bonds. The fractional abundance of these components allows us to place the Galactic diffuse ISM hydrocarbons on a ternary phase diagram. We conclude that the Galactic hydrocarbon dust has, on average, a low H/C ratio and sp 3 content and is highly aromatic. We have placed the results of our analysis within the context of the evolution of carbon dust in the ISM. We argue that interstellar carbon dust consists of a large core of aromatic carbon surrounded by a thin mantle of hydrogenated amorphous carbon (a-C:H), a structure that is a natural consequence of the processing of stardust grains in the ISM.

  20. The oil potential of the BM-J-2 block, Jequitinhonha basin, Brazil: the integrated study of the basin analysis and modeling of petroleum system; Potencial petrolifero do Bloco BM-J-2, Bacia de Jequitinhonha, Brasil: um estudo integrado de analise de bacia e modelagem de sistemas petroliferos

    Energy Technology Data Exchange (ETDEWEB)

    Porto, Roberto; Braga, Jose A.E.; Saito, Makoto; Cortez, Marcella; Ponte Filho, Francisco C.; Romao, Felipe [Queiroz Galvao Perfuracoes S.A., Rio de Janeiro, RJ (Brazil); Goncalves, Felix T.T. [PGT-Petroleum Geoscience Technology Ltd., Rio de Janeiro, RJ (Brazil)

    2004-07-01

    The integration of all available geochemical data from this and adjoining blocks (BM-J-1 e BM-J-3) Jequitinhonha Basin revealed that only the Albian-Turonian and Aptian sections contains potential hydrocarbon source rock intervals. The existence of an oil accumulation (1-BAS-37) represents an unequivocal evidence of the presence of effective source rocks in the Jequitinhonha Basin. The geochemical characteristics of this oil accumulation points to an origin related to petroleum source rocks deposited under a lacustrine/marine restricted (hyper saline) environment. Such characteristics are typical of pre-salt Aptian source rocks in several basins along the Brazilian margin. The pseudo-3D modeling results indicate that the stage of thermal evolution of the base of the rift section attained ranges from early mature (0.6-0.8 Ro) in the structural highs to over mature (up to 2.0% Ro) in the structural lows On the other hand, the potential sources rocks of Albian-Turonian age ranges to immature to early mature throughout the block. The modeling results also points to the existence of two distinct hydrocarbon 'kitchens': one located in the easternmost portion of the block (slope/deep water area) and the other in a structural low located in the shallow platform area. The main phase of petroleum expulsion ranged from Late Cretaceous/Paleogene in the platform area. Probabilistic simulations has estimated migrated oils and gas volumes around 507 MMbbl and 20 billion cubic meters, respectively. (author)

  1. Geophysical Signitures From Hydrocarbon Contaminated Aquifers

    Science.gov (United States)

    Abbas, M.; Jardani, A.

    2015-12-01

    The task of delineating the contamination plumes as well as studying their impact on the soil and groundwater biogeochemical properties is needed to support the remediation efforts and plans. Geophysical methods including electrical resistivity tomography (ERT), induced polarization (IP), ground penetrating radar (GPR), and self-potential (SP) have been previously used to characterize contaminant plumes and investigate their impact on soil and groundwater properties (Atekwana et al., 2002, 2004; Benson et al., 1997; Campbell et al., 1996; Cassidy et al., 2001; Revil et al., 2003; Werkema et al., 2000). Our objective was to: estimate the hydrocarbon contamination extent in a contaminated site in northern France, and to adverse the effects of the oil spill on the groundwater properties. We aim to find a good combination of non-intrusive and low cost methods which we can use to follow the bio-remediation process, which is planned to proceed next year. We used four geophysical methods including electrical resistivity tomography, IP, GPR, and SP. The geophysical data was compared to geochemical ones obtained from 30 boreholes installed in the site during the geophysical surveys. Our results have shown: low electrical resistivity values; high chargeability values; negative SP anomalies; and attenuated GPR reflections coincident with groundwater contamination. Laboratory and field geochemical measurements have demonstrated increased groundwater electrical conductivity and increased microbial activity associated with hydrocarbon contamination of groundwater. Our study results support the conductive model suggested by studies such as Sauck (2000) and Atekwana et al., (2004), who suggest that biological alterations of hydrocarbon contamination can substantially modify the chemical and physical properties of the subsurface, producing a dramatic shift in the geo-electrical signature from resistive to conductive. The next stage of the research will include time lapse borehole

  2. Resource Assessment of the In-Place and Potentially Recoverable Deep Natural Gas Resource of the Onshore Interior Salt Basins, North Central and Northeastern Gulf of Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Ernest A. Mancini; Paul Aharon; Donald A. Goddard; Roger Barnaby

    2005-10-28

    The principal research effort for Year 2 of the project has been petroleum system characterization and modeling. Understanding the burial, thermal maturation, and hydrocarbon expulsion histories of the strata in the onshore interior salt basins of the North Central and Northeastern Gulf of Mexico areas is important in hydrocarbon resource assessment. The underburden and overburden rocks in these basins and subbasins are a product of their rift-related geohistory. Petroleum source rock analysis and initial thermal maturation and hydrocarbon expulsion modeling indicated that an effective regional petroleum source rock in the onshore interior salt basins and subbasins, the North Louisiana Salt Basin, Mississippi Interior Salt Basin, Manila Subbasin and Conecuh Subbasin, was Upper Jurassic Smackover lime mudstone. The initial modeling also indicated that hydrocarbon generation and expulsion were initiated in the Early Cretaceous and continued into the Tertiary in the North Louisiana Salt Basin and the Mississippi Interior Salt Basin and that hydrocarbon generation and expulsion were initiated in the Late Cretaceous and continued into the Tertiary in the Manila Subbasin and Conecuh Subbasin. Refined thermal maturation and hydrocarbon expulsion modeling and additional petroleum source rock analysis have confirmed that the major source rock in the onshore interior salt basins and subbasins is Upper Jurassic Smackover lime mudstone. Hydrocarbon generation and expulsion were initiated in the Early to Late Cretaceous and continued into the Tertiary.

  3. Catalytic Upgrading of Sugars to Hydrocarbons Technology Pathway

    Energy Technology Data Exchange (ETDEWEB)

    Biddy, Mary J.; Jones, Susanne B.

    2013-03-31

    In support of the Bioenergy Technologies Office, the National Renewable Energy Laboratory (NREL) and the Pacific Northwest National Laboratory (PNNL) are undertaking studies of biomass conversion technologies to hydrocarbon fuels to identify barriers and target research toward reducing conversion costs. Process designs and preliminary economic estimates for each of these pathway cases were developed using rigorous modeling tools (Aspen Plus and Chemcad). These analyses incorporated the best information available at the time of development, including data from recent pilot and bench-scale demonstrations, collaborative industrial and academic partners, and published literature and patents. This technology pathway case investigates the catalytic conversion of solubilized carbohydrate streams to hydrocarbon biofuels, utilizing data from recent efforts within the National Advanced Biofuels Consortium (NABC) in collaboration with Virent, Inc.. Technical barriers and key research needs that should be pursued for the catalytic conversion of sugars pathway to be competitive with petroleum-derived gasoline, diesel and jet range hydrocarbon blendstocks have been identified.

  4. Electrochemical masstransfer of oil hydrocarbons in dispersed soils

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-07-01

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

  5. Hydrocarbon fermentation: kinetics of microbial cell growth

    Energy Technology Data Exchange (ETDEWEB)

    Goma, G [Institut National des Sciences Appliquees, Toulouse; Ribot, D

    1978-11-01

    Modeling of microbial growth using nonmiscible substrate is studied when kinetics of substrate dissolution is rate limiting. When the substrate concentration is low, the growth rate is described by an analytical relation that can be identified as a Contois relationship. If the substrate concentration is greater than a critical value S/sub crit/, the potentially useful hydrocarbon S* concentration is described by S* = S/sub crit//(1 + S/sub crit//S). A relationship was found between S/sub crit/ and the biomass concentration X. When X increased, S/sub crit/ decreased. The cell growth rate is related to a relation ..mu.. = ..mu../sub m/(A(X/S/sub crit/)(1 + S/sub crit//S) + 1)/sup -1/. This model describes the evolution of the growth rate when exponential or linear growth occurs, which is related to physico-chemical properties and hydrodynamic fermentation conditions. Experimental data to support the model are presented.

  6. Biodegradation of petroleum hydrocarbons in hypersaline environments

    Directory of Open Access Journals (Sweden)

    Luiz Fernando Martins

    2012-09-01

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

  7. Process for separating liquid hydrocarbons from waxes

    Energy Technology Data Exchange (ETDEWEB)

    Sowa, F J

    1948-03-08

    A process is described for the separation of liquid hydrocarbons from waxes comprising adding to a mixture of liquid hydrocarbons and waxes a sufficient quantity of an organo-silicon compound to cause the separation of the hydrocarbon and wax. The organo-silicon compounds are selected from the class of organic silicanes and their hydrolysis products and polymers. The silicanes have the formula R/sub y/SiX/sub z/, in which R is a saturated or unsaturated hydrocarbon radical, X is a halogen or another hydrocarbon radical or an -OR group, y has a value 1, 2, or 3 and z has a value 1, 2, or 3.

  8. Adsorption of polar aromatic hydrocarbons on synthetic calcite

    DEFF Research Database (Denmark)

    Madsen, Lene; Grahl-Madsen, Laila; Grøn, Christian

    1996-01-01

    The wettability of hydrocarbon reservoirs depends on how and to what extent the organic compounds are adsorbed onto the surfaces of calcite, quartz and clay. A model system of synthetic call cite, cyclohexane and the three probe molecules: benzoic acid, benzyl alcohol and benzylamine, have been...

  9. Microbial Degradation of Polycyclic Aromatic Hydrocarbons and Characterization of Bacteria

    Science.gov (United States)

    Tikilili, P. V.; Chirwa, E. M. N.

    2010-01-01

    Biodegradation of polycyclic aromatic hydrocarbons was studied. Naphthalene was used as a model compound to represent these compounds. Low initial concentrations of naphthalene in a range of 30-60 mg/L were completely degraded after incubation for 15 hrs by consortia from a landfill soil while consortia from minewater took more that 29 hrs to reach complete degradation.

  10. Hydrocarbon degradation potentials of bacteria isolated from spent ...

    African Journals Online (AJOL)

    Hydrocarbon degradation potentials of bacteria isolated from spent lubricating oil contaminated soil. ... This study has shown that resident bacteria strains in lubricating oil contaminated soils have potential application in the bioremediation of oil polluted sites and enhance the possibility of developing models and strategies ...

  11. Chemical Kinetics of Hydrocarbon Ignition in Practical Combustion Systems

    International Nuclear Information System (INIS)

    Westbrook, C.K.

    2000-01-01

    Chemical kinetic factors of hydrocarbon oxidation are examined in a variety of ignition problems. Ignition is related to the presence of a dominant chain branching reaction mechanism that can drive a chemical system to completion in a very short period of time. Ignition in laboratory environments is studied for problems including shock tubes and rapid compression machines. Modeling of the laboratory systems are used to develop kinetic models that can be used to analyze ignition in practical systems. Two major chain branching regimes are identified, one consisting of high temperature ignition with a chain branching reaction mechanism based on the reaction between atomic hydrogen with molecular oxygen, and the second based on an intermediate temperature thermal decomposition of hydrogen peroxide. Kinetic models are then used to describe ignition in practical combustion environments, including detonations and pulse combustors for high temperature ignition, and engine knock and diesel ignition for intermediate temperature ignition. The final example of ignition in a practical environment is homogeneous charge, compression ignition (HCCI) which is shown to be a problem dominated by the kinetics intermediate temperature hydrocarbon ignition. Model results show why high hydrocarbon and CO emissions are inevitable in HCCI combustion. The conclusion of this study is that the kinetics of hydrocarbon ignition are actually quite simple, since only one or two elementary reactions are dominant. However, there are many combustion factors that can influence these two major reactions, and these are the features that vary from one practical system to another

  12. Hydrocarbon saturation determination using acoustic velocities obtained through casing

    Science.gov (United States)

    Moos, Daniel

    2010-03-09

    Compressional and shear velocities of earth formations are measured through casing. The determined compressional and shear velocities are used in a two component mixing model to provides improved quantitative values for the solid, the dry frame, and the pore compressibility. These are used in determination of hydrocarbon saturation.

  13. Tolerance of Antarctic soil fungi to hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    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

    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)

  14. Hydrocarbon Rocket Technology Impact Forecasting

    Science.gov (United States)

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

    2012-01-01

    Ever since the Apollo program ended, the development of launch propulsion systems in the US has fallen drastically, with only two new booster engine developments, the SSME and the RS-68, occurring in the past few decades.1 In recent years, however, there has been an increased interest in pursuing more effective launch propulsion technologies in the U.S., exemplified by the NASA Office of the Chief Technologist s inclusion of Launch Propulsion Systems as the first technological area in the Space Technology Roadmaps2. One area of particular interest to both government agencies and commercial entities has been the development of hydrocarbon engines; NASA and the Air Force Research Lab3 have expressed interest in the use of hydrocarbon fuels for their respective SLS Booster and Reusable Booster System concepts, and two major commercially-developed launch vehicles SpaceX s Falcon 9 and Orbital Sciences Antares feature engines that use RP-1 kerosene fuel. Compared to engines powered by liquid hydrogen, hydrocarbon-fueled engines have a greater propellant density (usually resulting in a lighter overall engine), produce greater propulsive force, possess easier fuel handling and loading, and for reusable vehicle concepts can provide a shorter turnaround time between launches. These benefits suggest that a hydrocarbon-fueled launch vehicle would allow for a cheap and frequent means of access to space.1 However, the time and money required for the development of a new engine still presents a major challenge. Long and costly design, development, testing and evaluation (DDT&E) programs underscore the importance of identifying critical technologies and prioritizing investment efforts. Trade studies must be performed on engine concepts examining the affordability, operability, and reliability of each concept, and quantifying the impacts of proposed technologies. These studies can be performed through use of the Technology Impact Forecasting (TIF) method. The Technology Impact

  15. Microbial production of gaseous hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Fukuda, Hideo

    1987-10-20

    Microbial production of ethylene, isobutane and a saturated gaseous hydrocarbon mixture was described. Microbial ethylene production was studied with Penicillium digitatum IFO 9372 and a novel pathway of the ethylene biosynthesis through alpha-ketoglutarate was proposed. Rhodotorula minuta IFO 1102 was selected for the microbial production of isobutane and the interesting actions of L-leucine and L-phenylalanine for the isobutane production were found. It was finally presented about the microbial production of a saturated gaseous hydrocarbon mixture with Rhizopus japonicus IFO 4758 was described. A gas mixture was produced through a chemical reaction of SH compounds and some cellular component such as squalene under aerobic conditions. (4 figs, 7 tabs, 41 refs)

  16. Scottish hydrocarbons: Borders and bounty

    International Nuclear Information System (INIS)

    Roberts, John

    1999-01-01

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

  17. Treatment of hydrocarbon oil vapours

    Energy Technology Data Exchange (ETDEWEB)

    Lamplough, F

    1923-03-01

    An apparatus for treating hydrocarbon vapors for the purpose of preventing dehydrogenation is disclosed which comprises in combination a cooling tower having a vapor inlet at the bottom and a vapor outlet at the top, means to direct the entering vapors laterally in a plurality of jets against an interior side wall or walls of the tower and means to constrain the condensate to gravitate down the tower in the interior wall or walls against which the encountering vapor is forced to impinge.

  18. Deep desulfurization of hydrocarbon fuels

    Science.gov (United States)

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

    2012-04-17

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

  19. Source rock hydrocarbons. Present status

    International Nuclear Information System (INIS)

    Vially, R.; Maisonnier, G.; Rouaud, T.

    2013-01-01

    This report first presents the characteristics of conventional oil and gas system, and the classification of liquid and gaseous non conventional hydrocarbons, with the peculiar case of coal-bed methane. The authors then describe how source rock hydrocarbons are produced: production of shale oils and gases (horizontal drilling, hydraulic fracturing, exploitation) and of coal-bed methane and coal mine methane. In the next part, they address and discuss the environmental impact of source rock hydrocarbon production: installation footprint, water resource management, drilling fluids, fracturing fluids composition, toxicity and recycling, air pollution, induced seismicity, pollutions from other exploitation and production activities. They propose an overview of the exploitation and production of source rock gas, coal-bed gas and other non conventional gases in the world. They describe the current development and discuss their economic impacts: world oil context and trends in the USA, in Canada and other countries, impacts on the North American market, on the world oil industry, on refining industries, on the world oil balance. They analyse the economic impacts of non conventional gases: development potential, stakes for the world gas trade, consequence for gas prices, development opportunities for oil companies and for the transport sector, impact on CO 2 emissions, macro-economic impact in the case of the USA

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

    Science.gov (United States)

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

    2014-05-01

    Seepage of methane-dominated hydrocarbons is heterogeneous in space and time, and trigger mechanisms of episodic seep events are not well constrained. It is generally found that free hydrocarbon gas entering the local gas hydrate stability field in marine sediments is sequestered in gas hydrates. In this manner, gas hydrates can act as a buffer for carbon transport from the sediment into the ocean. However, the efficiency of gas hydrate-bearing sediments for retaining hydrocarbons may be corrupted: Hypothesized mechanisms include critical gas/fluid pressures beneath gas hydrate-bearing sediments, implying that these are susceptible to mechanical failure and subsequent gas release. Although gas hydrates often occur in seismically active regions, e.g., subduction zones, the role of earthquakes as potential triggers of hydrocarbon transport through gas hydrate-bearing sediments has hardly been explored. Based on a recent publication (Fischer et al., 2013), we present geochemical and transport/reaction-modelling data suggesting a substantial increase in upward gas flux and hydrocarbon emission into the water column following a major earthquake that occurred near the study sites in 1945. Calculating the formation time of authigenic barite enrichments identified in two sediment cores obtained from an anticlinal structure called "Nascent Ridge", we find they formed 38-91 years before sampling, which corresponds well to the time elapsed since the earthquake (62 years). Furthermore, applying a numerical model, we show that the local sulfate/methane transition zone shifted upward by several meters due to the increased methane flux and simulated sulfate profiles very closely match measured ones in a comparable time frame of 50-70 years. We thus propose a causal relation between the earthquake and the amplified gas flux and present reflection seismic data supporting our hypothesis that co-seismic ground shaking induced mechanical fracturing of gas hydrate-bearing sediments

  1. Thermal stability of hydrocarbons in nature: Limits, evidence, characteristics, and possible controls

    Science.gov (United States)

    Price, L.C.

    1993-01-01

    Numerous petroleum-geochemical analyses of deeply buried, high-rank, fine-grained rocks from ultra-deep wellbores by different investigators demonstrate that C15+ hydrocarbons (HCs) persist in moderate to high concentrations at vitrinite reflectance (R0) values of 2.0-5.0% and persist in measurable concentrations up to R0 = 7.0-8.0%, at which point the thermal deadline for C15+ HC's is finally approached. Qualitative analyses have been carried out on 1. (1) high-rank gas condensates which have been exposed to the HC-thermal-destructive phase, 2. (2) bitumens from high-temperature aqueous-pyrolysis experiments in the HC-thermal-destructive phase, and 3. (3) bitumens from high-rank, fine-grained rocks near the HC-thermal-destructive phase. These analyses clearly demonstrate that well-defined compositional suites are established in the saturated, aromatic, and sulfur-bearing aromatic HCs in and near the HC-thermal-destructive phase. On the other hand, accepted petroleum-geochemical paradigms place rigid limits on HC thermal stability: C15+ HCs begin thermal cracking at R0 values of 0.9% and are completely thermally destroyed by R0 = 1.35%; C2-C4 HC gases are thermally destroyed by R0 = 2.0% and methane is thermally destroyed by R0 = 4.0%. Furthermore, published data and observations in many HC basins worldwide support these models; for example, 1. (1) sharp basinal zonations of gas and oil deposits vs. maturation rank in HC basins and 2. (2) decreasing C15+ HC concentrations in some fine-grained rocks at ranks of R0 ??? 0.9%. The fact that observed data (C15+ HCs thermally stable to R0 = 7.0-8.0%) is so far removed from predicted behavior (C15+) HCs expected to be thermally destroyed by R0 = 1.35%) may be due to 1. (1) a lack of recognition of some important possible controlling parameters of organic matter (OM) metamorphism and too much importance given to other assumed controlling parameters; and 2. (2) assigning HC distribution patterns in petroleum basins to HC

  2. Dynamics of a bright soliton in Bose-Einstein condensates with time-dependent atomic scattering length in an expulsive parabolic potential

    International Nuclear Information System (INIS)

    Liang, Z.X.; Zhang, Z.D.; Liu, W.M.

    2005-01-01

    We present a family of exact solutions of the one-dimensional nonlinear Schroedinger equation which describes the dynamics of a bright soliton in Bose-Einstein condensates with the time-dependent interatomic interaction in an expulsive parabolic potential. Our results show that, under a safe range of parameters, the bright soliton can be compressed into very high local matter densities by increasing the absolute value of the atomic scattering length, which can provide an experimental tool for investigating the range of validity of the one-dimensional Gross-Pitaevskii equation. We also find that the number of atoms in the bright soliton keeps dynamic stability: a time-periodic atomic exchange is formed between the bright soliton and the background

  3. Improved ZIF-8 membrane: Effect of activation procedure and determination of diffusivities of light hydrocarbons

    KAUST Repository

    Pan, Yichang; Liu, Wei; Zhao, Yingjie; Wang, Chongqing; Lai, Zhiping

    2015-01-01

    Zeolitic imidazolate framework ZIF-8 has shown great potential for effective separation of hydrocarbon mixtures based on its intrinsic ultramicroporous feature. In order to explore the permeation and diffusion properties of hydrocarbons through ZIF-8 membrane, high-quality ZIF-8 membranes with a separation factor of ~90 for propylene/propane are successfully prepared via optimizing the activation processes. Single-component permeation data for hydrocarbons (C1–C4) through the improved ZIF-8 membrane are measured and analyzed by Maxwell-Stefan (MS) model to get the transport diffusivities of these hydrocarbons. The diffusivity values of hydrocarbon compare well with those obtained by other experimental techniques. Binary mixture permeation also can be well predicted through single-component adsorption parameters.

  4. Improved ZIF-8 membrane: Effect of activation procedure and determination of diffusivities of light hydrocarbons

    KAUST Repository

    Pan, Yichang

    2015-06-23

    Zeolitic imidazolate framework ZIF-8 has shown great potential for effective separation of hydrocarbon mixtures based on its intrinsic ultramicroporous feature. In order to explore the permeation and diffusion properties of hydrocarbons through ZIF-8 membrane, high-quality ZIF-8 membranes with a separation factor of ~90 for propylene/propane are successfully prepared via optimizing the activation processes. Single-component permeation data for hydrocarbons (C1–C4) through the improved ZIF-8 membrane are measured and analyzed by Maxwell-Stefan (MS) model to get the transport diffusivities of these hydrocarbons. The diffusivity values of hydrocarbon compare well with those obtained by other experimental techniques. Binary mixture permeation also can be well predicted through single-component adsorption parameters.

  5. Self-ignition and oxidation of various hydrocarbons between 600 and 1000 K at high pressure: experimental study with fast compression machine and modeling; Autoinflammation et oxydation de divers hydrocarbures entre 600 et 1000 K a haute pression: etude experimentale en machine a compression rapide et modelisation

    Energy Technology Data Exchange (ETDEWEB)

    Ribaucour, M.

    2002-12-01

    Low- and intermediate-temperature oxidation and self-ignition of hydrocarbons play a major role in spark ignition, diesel and HCCI (homogenous charge compression ignition) engines. A deep understanding of the chemistry linked with both phenomena is necessary to improve the engines efficiency and to reduce the formation of pollutants. This document treats of works about the self-ignition and oxidation at high pressure of various hydrocarbons between 600 and 1000 deg. K. The experimental tool used is a fast compression machine fitted with a fast sampling system for the measurement of self-ignition delays and of the concentrations of intermediate oxidation products. The advantages and limitations of this tool are discussed. The self-ignition of various hydrocarbons is compared using pre-defined data which characterize the phenomenologies like cold flames, negative temperature coefficients and self-ignition limits. The hydrocarbons considered are pure or binary mixtures of alkanes, pent-1-ene and n-butyl-benzene. The development of high pressure oxidation reaction schemes of alkanes between 600 and 1000 deg. K is described. It is directly based on the analysis of intermediate oxidation products. This methodology is also applied to pent-1-ene and n-butyl-benzene. The construction of detailed thermo-kinetic models of oxidation and the modeling of phenomena are made for n-butane, n-heptane, for the 3 pentane isomers, for pent-1-ene and n-butyl-benzene. Finally, the perspectives of future works are evoked. They concern new modeling and new methodologies to be applied in more predictive thermo-kinetic models and the reduction of detailed models in order to include them inside fluid dynamics codes. (J.S.)

  6. Calculating in situ degradation rates of hydrocarbon compounds in deep waters of the Gulf of Mexico.

    Science.gov (United States)

    Thessen, Anne E; North, Elizabeth W

    2017-09-15

    Biodegradation is an important process for hydrocarbon weathering that influences its fate and transport, yet little is known about in situ biodegradation rates of specific hydrocarbon compounds in the deep ocean. Using data collected in the Gulf of Mexico below 700m during and after the Deepwater Horizon oil spill, we calculated first-order degradation rate constants for 49 hydrocarbons and inferred degradation rate constants for an additional 5 data-deficient hydrocarbons. Resulting calculated (not inferred) half-lives of the hydrocarbons ranged from 0.4 to 36.5days. The fastest degrading hydrocarbons were toluene (k=-1.716), methylcyclohexane (k=-1.538), benzene (k=-1.333), and C1-naphthalene (k=-1.305). The slowest degrading hydrocarbons were the large straight-chain alkanes, C-26 through C-33 (k=-0.0494 through k=-0.007). Ratios of C-18 to phytane supported the hypothesis that the primary means of degradation in the subsurface was microbial biodegradation. These degradation rate constants can be used to improve models describing the fate and transport of hydrocarbons in the event of an accidental deep ocean oil spill. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. The use of paleo-thermo-barometers and coupled thermal, fluid flow and pore fluid pressure modelling for hydrocarbon and reservoir prediction in fold and thrust belts

    NARCIS (Netherlands)

    Roure, F.; Andriessen, P.A.M.; Callot, J.P.; Ferket, H.; Gonzales, E.; Guilhaumou, N.; Hardebol, N.J.; Lacombe, O.; Malandain, J.; Mougin, P.; Muska, K.; Ortuno, S.; Sassi, W.; Swennen, R.; Vilasi, N.

    2010-01-01

    Basin modelling tools are now more efficient to reconstruct palinspastic structural cross sections and compute the history of temperature, pore-fluid pressure and fluid flow circulations in complex structural settings. In many cases and especially in areas where limited erosion occurred, the use of

  8. Thermodynamic Description of Liquid-Liquid Equilibria in Systems 1-Ethyl-3-methylimidazolium Ethylsulfate + C7-Hydrocarbons by Polymer-Solution Models

    Czech Academy of Sciences Publication Activity Database

    Bendová, Magdalena; Wagner, Zdeněk

    2009-01-01

    Roč. 284, č. 2 (2009), s. 80-85 ISSN 0378-3812 R&D Projects: GA ČR GA104/07/0444; GA ČR GP104/06/P066; GA AV ČR IAA400720710 Institutional research plan: CEZ:AV0Z40720504 Keywords : liquid-liquid equilibrium * ionic liquids * thermodynamic model Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.857, year: 2009

  9. Detection of hydrocarbons in irradiated foods

    International Nuclear Information System (INIS)

    Miyahara, Makoto; Maitani, Tamio; Saito, Akiko; Kamimura, Tomomi; Nagasawa, Taeko; Kobayashi, Yasuo; Ito, Hitoshi

    2003-01-01

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

  10. Detection of hydrocarbons in irradiated foods

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-06-01

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

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

    OpenAIRE

    Kleindienst, Sara

    2012-01-01

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

  12. Halogenated hydrocarbons - an environmental problem

    Energy Technology Data Exchange (ETDEWEB)

    Schoeler, H F; Thofern, E

    1984-01-01

    The paper provides a survey of the incidence of highly volatile halogenated hydrocarbons in ground, surface and drinking water as well as in the snows of Western Germany. Almost the entire production of chlorinated solvents is released into the environment. The absorption media are mostly soil, water and atmosphere. Whereas in the atmosphere elimination reactions take place, solvents that have passed the soil get into the ground water owing to their persistence and can cause considerable pollutions of drinking water. Moreover haloforms may occur in drinking water, which are produced during chlorine disinfection of pre-treated water.

  13. Catalytic treatment of hydrocarbon oils

    Energy Technology Data Exchange (ETDEWEB)

    1940-02-23

    A process is described for increasing the octane number of a hydrocarbon oil. The substance is subjected under pressure to a temperature between 800 and 1100/sup 0/C. Catalysts include metal compounds of Groups IV, V, Vi, or VIII (Group VI is perferred). Experiments are performed under a hydrogen atmosphere. Reaction time, temperature, pressure, and partial pressure of the hydrogen are adjusted so that there will be no net hydrogen consumption. The reaction gases (including the products) are recycled in whole or in part to supply the hydrogen gas required.

  14. Catalytic cracking of hydrocarbon oils

    Energy Technology Data Exchange (ETDEWEB)

    1940-09-12

    A process is described for the vapor phase catalytic cracking of hydrocarbon oils boiling substantially in the gas oil range. The reaction takes place in the presence of a solid catalyst between 700 to 900/sup 0/F under pressure between atmospheric and 400 psi. A gas containing between 20 and 90 mol % of free hydrogen is used. The reaction is allowed to proceed until consumption of the free begins. The reaction is discontinued at that point and the catalyst is regenerated for further use.

  15. Performance of a Throttle Cycle Refrigerator with Nitrogen-Hydrocarbon and Argon-Hydrocarbon Mixtures

    Science.gov (United States)

    Venkatarathnam, G.; Senthil Kumar, P.; Srinivasa Murthy, S.

    2004-06-01

    Throttle cycle refrigerators are a class of vapor compression refrigerators that can provide refrigeration at cryogenic temperatures and operate with refrigerant mixtures. The performance of our prototype refrigerators with nitrogen-hydrocarbon, nitrogen-hydrocarbon-helium and argon-hydrocarbon refrigerant mixtures is presented in this paper.

  16. Hydrocarbons and energy from plants: Final report, 1984-1987

    Energy Technology Data Exchange (ETDEWEB)

    Calvin, M.; Otvos, J.; Taylor, S.E.; Nemethy, E.K.; Skrukrud, C.L.; Hawkins, D.R.; Lago, R.

    1988-08-01

    Plant hydrocarbon (isoprenoid) production was investigated as an alternative source to fossil fuels. Because of their high triterpenoid (hydrocarbon) content of 4--8%, Euphorbia lathyris plants were used as a model system for this study. The structure of the E. lathyris triterpenoids was determined, and triterpenoid biosynthesis studied to better understand the metabolic regulation of isoprenoid production. Triterpenoid biosynthesis occurs in two distinct tissue types in E. lathyris plants: in the latex of the laticifer cells; and in the mesophyll cells of the leaf and stem. The latex has been fractionated by centrifugation, and it has been determined that the later steps of isoprenoid biosynthesis, the conversion of mevalonic acid to the triterpenes, are compartmentized within a vacuole. Also identified was the conversion of hydroxymethyl glutaryl-CoA to mevalonic acid, catalyzed by the enzyme Hydroxymethyl glutaryl-CoA Reductase, as a key rate limiting step in isoprenoid biosynthesis. At least two isozymes of this enzyme, one in the latex and another in the leaf plastids, have been identified. Environmental stress has been applied to plants to study changes in carbon allocation. Salinity stress caused a large decrease in growth, smaller decreases in photosynthesis, resulting in a larger allocation of carbon to both hydrocarbon and sugar production. An increase in Hydroxymethyl glutaryl-CoA Reductase activity was also observed when isoprenoid production increased. Other species where also screened for the production of hydrogen rich products such as isoprenoids and glycerides, and their hydrocarbon composition was determined.

  17. Degradation of polynuclear aromatic hydrocarbons by two strains of Pseudomonas.

    Science.gov (United States)

    Nwinyi, Obinna C; Ajayi, Oluseyi O; Amund, Olukayode O

    2016-01-01

    The goal of this investigation was to isolate competent polynuclear aromatic hydrocarbons degraders that can utilize polynuclear aromatic hydrocarbons of former industrial sites at McDoel Switchyard in Bloomington, Indiana. Using conventional enrichment method based on soil slurry, we isolated, screened and purified two bacterial species strains PB1 and PB2. Applying the ribotyping technique using the 16S rRNA gene analysis, the strains were assigned to the genus Pseudomonas (Pseudomonas plecoglossicida strain PB1 and Pseudomonas sp. PB2). Both isolates showed promising metabolic capacity on pyrene sprayed MS agar plates during the preliminary investigations. Using time course studies in the liquid cultures at calculated concentrations 123, 64, 97 and 94ppm for naphthalene, chrysene, fluroanthene and pyrene, P. plecoglossicida strain PB1 and Pseudomonas sp. PB2 showed partial utilization of the polynuclear aromatic hydrocarbons. Naphthalene was degraded between 26% and 40%, chrysene 14% and 16%, fluroanthene 5% and 7%; pyrene 8% and 13% by P. plecoglossicida strain PB1 and Pseudomonas sp. PB2 respectively. Based on their growth profile, we developed a model R(2)=1 to predict the degradation rate of slow polynuclear aromatic hydrocarbon-degraders where all the necessary parameters are constant. From this investigation, we confirm that the former industrial site soil microbial communities may be explored for the biorestoration of the industrial site. Copyright © 2016. Published by Elsevier Editora Ltda.

  18. Positron induced scattering cross sections for hydrocarbons relevant to plasma

    Science.gov (United States)

    Singh, Suvam; Antony, Bobby

    2018-05-01

    This article explores positron scattering cross sections by simple hydrocarbons such as ethane, ethene, ethyne, propane, and propyne. Chemical erosion processes occurring on the surface due to plasma-wall interactions are an abundant source of hydrocarbon molecules which contaminate the hydrogenic plasma. These hydrocarbons play an important role in the edge plasma region of Tokamak and ITER. In addition to this, they are also one of the major components in the planetary atmospheres and astrophysical mediums. The present work focuses on calculation of different positron impact interactions with simple hydrocarbons in terms of the total cross section (Qtot), elastic cross section (Qel), direct ionization cross section (Qion), positronium formation cross section (Qps), and total ionization cross section (Qtion). Knowing that the positron-plasma study is one of the trending fields, the calculated data have diverse plasma and astrophysical modeling applications. A comprehensive study of Qtot has been provided where the inelastic cross sections have been reported for the first time. Comparisons are made with those available from the literature, and a good agreement is obtained with the measurements.

  19. Direct hydrocarbon exploration and gas reservoir development technology

    Energy Technology Data Exchange (ETDEWEB)

    Kwak, Young Hoon; Oh, Jae Ho; Jeong, Tae Jin [Korea Inst. of Geology Mining and Materials, Taejon (Korea, Republic of); and others

    1995-12-01

    In order to enhance the capability of petroleum exploration and development techniques, three year project (1994 - 1997) was initiated on the research of direct hydrocarbon exploration and gas reservoir development. This project consists of four sub-projects. (1) Oil(Gas) - source rock correlation technique: The overview of bio-marker parameters which are applicable to hydrocarbon exploration has been illustrated. Experimental analysis of saturated hydrocarbon and bio-markers of the Pohang E and F core samples has been carried out. (2) Study on surface geochemistry and microbiology for hydrocarbon exploration: the test results of the experimental device for extraction of dissolved gases from water show that the device can be utilized for the gas geochemistry of water. (3) Development of gas and gas condensate reservoirs: There are two types of reservoir characterization. For the reservoir formation characterization, calculation of conditional simulation was compared with that of unconditional simulation. In the reservoir fluid characterization, phase behavior calculations revealed that the component grouping is more important than the increase of number of components. (4) Numerical modeling of seismic wave propagation and full waveform inversion: Three individual sections are presented. The first one is devoted to the inversion theory in general sense. The second and the third sections deal with the frequency domain pseudo waveform inversion of seismic reflection data and refraction data respectively. (author). 180 refs., 91 figs., 60 tabs.

  20. Decontamination of hydrocarbon contaminated soil

    International Nuclear Information System (INIS)

    Smith, A.J.

    1991-01-01

    This patent describes the method of treating hydrocarbon contaminated soil. It comprises forming the soil into a flowing particulate stream, forming an aqueous liquid mixture of water and treating substance that reacts with hydrocarbon to form CO 2 and water, dispersing the liquid mixture into the particulate soil stream to wet the particulate, allowing the substance to react with the wetted soil particulate to thereby form CO 2 and water, thereby the resultant soil is beneficially treated, the stream being freely projected to dwell at a level and then fall, and the dispersing includes spraying the liquid mixture into the projected stream at the dwell, the substance consisting of natural bacteria, and at a concentration level in the mixture of between 100 to 3,000 PPM of bacteria to water, the soil forming step including impacting the soil to reduce it to particles less than about 1 inches in cross dimension, and including forming the wetting particulate into a first layer on a surface to allow the substance to react

  1. Hydrocarbon production with nuclear explosives

    International Nuclear Information System (INIS)

    Wade Watkins, J.

    1970-01-01

    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)

  2. Hydrocarbon production with nuclear explosives

    Energy Technology Data Exchange (ETDEWEB)

    Wade Watkins, J [Petroleum Research, Bureau of Mines, U.S. Department of the Interior, Washington, DC (United States)

    1970-05-01

    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)

  3. Unsaturated medium hydrocarbons pollution evaluation

    International Nuclear Information System (INIS)

    Di Luise, G.

    1991-01-01

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

  4. Production of hydrogen from hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Lohmueller, R

    1984-03-01

    Hydrocarbons are the preferred starting materials for the industrial production of hydrogen. Most hydrogen is produced by steam reforming of light hydrocarbons. Partial oxidation of heavy oil and residue is used for the production of H/sub 2/ and synthesis gas in large plants. In both cases gas purification was improved. Hydrogen-rich gases like coke oven gas, refinery-offgas, and offgases from the chemical and petrochemical industry have high potential for becoming a major source of hydrogen. Processes for recovering H/sub 2/ (and by-products) are condensation and rectification at low temperatures and, most attractive and versatile for the production of very pure H/sub 2/, adsorption (PSA). The environmental impact of H/sub 2/ production lies mainly in the emission of CO/sub 2/ and heat. Other forms of pollution can be considerably reduced by conventional methods. The economy of H/sub 2/ production depends essentially on price and availability of the raw materials.

  5. The electrostatic atomization of hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, A J

    1984-06-01

    Exploitation of the unique and potentially beneficial characteristics of electrostatic atomization in combustion systems has foundered upon the inability of two element, diode devices to operate at flow rates that are larger than a fraction of a millilitre per second. This restriction has been attributed to the high innate electrical resistivity of hydrocarbon fuels. A discussion of proposed electrostatic fuel atomizers and their limitations is presented from the vantage of a recently developed theory of electrostatic spraying. Comparison of theory and experiment reveals the existence of a 'constant of spraying' and the presence of an operational regime in which low charge density droplet development is possible. Operation with hydrocarbons in this regime occurs when the mean droplet size is greater than or equal to 10 ..mu..m and fluid viscosity is below about 250 cp. The resulting spray has a mean droplet size that is functionally dependent only upon the free charge density level of the fluid. Consequently there is no theoretical impediment to the attainment of high flow rate electrostatic atomization with fluids of arbitrary conductivity. Implementation is achieved by a general class of electrostatic spray devices which employ direct charge injection. The Spray Triode, a submerged field-emission electron gun, represents a particularly simple member of this new class of atomizer. Among the Spray Triode operational characteristics to be discussed is insensitivity to spray fluid properties and flow rate.

  6. Primary biodegradation of petroleum hydrocarbons in seawater

    Energy Technology Data Exchange (ETDEWEB)

    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

    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.

  7. Identification and Characterisation of Major Hydrocarbons in ...

    African Journals Online (AJOL)

    Identification and Characterisation of Major Hydrocarbons in Thermally Degraded Low Density Polyethylene Films. ... There were alkanes, alkenes, halogenated alkanes, and very few aromatics in the liquid product and, the hydrocarbons were observed to range between C10 - C27. The FTIR and GC-MS results show the ...

  8. Molecular characterization of autochthonous hydrocarbon utilizing ...

    African Journals Online (AJOL)

    Prof. Ogunji

    Materials and Methods ... culturable hydrocarbon utilizing bacteria (HUB) were enumerated by vapour phase ... hydrocarbon utilizing bacterial isolates by boiling method according to ... obtained in this investigation are consistent with past field studies (Kostka et ... Microbial and other related changes in a Niger sediment.

  9. Versatility of hydrocarbon production in cyanobacteria.

    Science.gov (United States)

    Xie, Min; Wang, Weihua; Zhang, Weiwen; Chen, Lei; Lu, Xuefeng

    2017-02-01

    Cyanobacteria are photosynthetic microorganisms using solar energy, H 2 O, and CO 2 as the primary inputs. Compared to plants and eukaryotic microalgae, cyanobacteria are easier to be genetically engineered and possess higher growth rate. Extensive genomic information and well-established genetic platform make cyanobacteria good candidates to build efficient biosynthetic pathways for biofuels and chemicals by genetic engineering. Hydrocarbons are a family of compounds consisting entirely of hydrogen and carbon. Structural diversity of the hydrocarbon family is enabled by variation in chain length, degree of saturation, and rearrangements of the carbon skeleton. The diversified hydrocarbons can be used as valuable chemicals in the field of food, fuels, pharmaceuticals, nutrition, and cosmetics. Hydrocarbon biosynthesis is ubiquitous in bacteria, yeasts, fungi, plants, and insects. A wide variety of pathways for the hydrocarbon biosynthesis have been identified in recent years. Cyanobacteria may be superior chassis for hydrocabon production in a photosynthetic manner. A diversity of hydrocarbons including ethylene, alkanes, alkenes, and terpenes can be produced by cyanobacteria. Metabolic engineering and synthetic biology strategies can be employed to improve hydrocarbon production in cyanobacteria. This review mainly summarizes versatility and perspectives of hydrocarbon production in cyanobacteria.

  10. 33 CFR 157.166 - Hydrocarbon emissions.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Hydrocarbon emissions. 157.166 Section 157.166 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... Crude Oil Washing (COW) System on Tank Vessels Cow Operations § 157.166 Hydrocarbon emissions. If the...

  11. Hydrocarbon formation mechanism during uranium monocarbide hydrolysis

    International Nuclear Information System (INIS)

    Ermolaev, M.I.; Tishchenko, G.V.

    1979-01-01

    The hydrolysis of uranium monocarbide in oxidative media and in the presence of excessive hydrogen in statu nascendi has been investigated. It was found that oxydants promote the formation of elementary carbon, while in the presence of hydrogen the yield of light C-C hydrocarbons increases. EPR data confirm the radical mechanism of hydrocarbons formation during the decomposition of uranium monocarbide

  12. George A. Olah, Carbocation and Hydrocarbon Chemistry

    Science.gov (United States)

    dropdown arrow Site Map A-Z Index Menu Synopsis George A. Olah, Carbocation and Hydrocarbon Chemistry George Olah received the 1994 Nobel Prize in Chemistry "for his contribution to carbocation chemistry" and his 'role in the chemistry of hydrocarbons. In particular, he developed superacids

  13. Hydrocarbons biodegradation in unsaturated porous medium

    International Nuclear Information System (INIS)

    Gautier, C.

    2007-12-01

    Biological processes are expected to play an important role in the degradation of petroleum hydrocarbons in contaminated soils. However, factors influencing the kinetics of biodegradation are still not well known, especially in the unsaturated zone. To address these biodegradation questions in the unsaturated zone an innovative experimental set up based on a physical column model was developed. This experimental set up appeared to be an excellent tool for elaboration of a structured porous medium, with well defined porous network and adjusted water/oil saturations. Homogeneous repartition of both liquid phases (i.e., aqueous and non aqueous) in the soil pores, which also contain air, was achieved using ceramic membranes placed at the bottom of the soil column. Reproducible interfaces (and connectivity) are developed between gas, and both non mobile water and NAPL phases, depending on the above-defined characteristics of the porous media and on the partial saturations of these three phases (NAPL, water and gas). A respirometric apparatus was coupled to the column. Such experimental set up have been validated with hexadecane in dilution in an HMN phase. This approach allowed detailed information concerning n-hexadecane biodegradation, in aerobic condition, through the profile of the oxygen consumption rate. We have taken benefit of this technique, varying experimental conditions, to determine the main parameters influencing the biodegradation kinetics and compositional evolution of hydrocarbons, under steady state unsaturated conditions and with respect to aerobic metabolism. Impacts of the nitrogen quantity and of three different grain sizes have been examined. Biodegradation of petroleum cut, as diesel cut and middle distillate without aromatic fraction, were, also studied. (author)

  14. Interaction between hydrocarbon seepage, chemosynthetic communities, and bottom water redox at cold seeps of the Makran accretionary prism: insights from habitat-specific pore water sampling and modeling

    Directory of Open Access Journals (Sweden)

    D. Fischer

    2012-06-01

    Full Text Available The interaction between fluid seepage, bottom water redox, and chemosynthetic communities was studied at cold seeps across one of the world's largest oxygen minimum zones (OMZ located at the Makran convergent continental margin. Push cores were obtained from seeps within and below the core-OMZ with a remotely operated vehicle. Extracted sediment pore water was analyzed for sulfide and sulfate concentrations. Depending on oxygen availability in the bottom water, seeps were either colonized by microbial mats or by mats and macrofauna. The latter, including ampharetid polychaetes and vesicomyid clams, occurred in distinct benthic habitats, which were arranged in a concentric fashion around gas orifices. At most sites colonized by microbial mats, hydrogen sulfide was exported into the bottom water. Where macrofauna was widely abundant, hydrogen sulfide was retained within the sediment.

    Numerical modeling of pore water profiles was performed in order to assess rates of fluid advection and bioirrigation. While the magnitude of upward fluid flow decreased from 11 cm yr−1 to <1 cm yr−1 and the sulfate/methane transition (SMT deepened with increasing distance from the central gas orifice, the fluxes of sulfate into the SMT did not significantly differ (6.6–9.3 mol m−2 yr−1. Depth-integrated rates of bioirrigation increased from 120 cm yr−1 in the central habitat, characterized by microbial mats and sparse macrofauna, to 297 cm yr−1 in the habitat of large and few small vesicomyid clams. These results reveal that chemosynthetic macrofauna inhabiting the outer seep habitats below the core-OMZ efficiently bioirrigate and thus transport sulfate down into the upper 10 to 15 cm of the sediment. In this way the animals deal with the lower upward flux of methane in outer habitats by stimulating rates of anaerobic oxidation of methane (AOM with sulfate high enough to provide

  15. Decree 316/011. It approve the bases for the oil companies selection process about the hydrocarbons exploration and exploitation in the Republica Oriental del Uruguay offshore Round II including the respective model contract

    International Nuclear Information System (INIS)

    2011-01-01

    This decree approve the bases for the oil companies interested in the hydrocarbons exploration and exploitation in the Republica Oriental del Uruguay. The energetic fossil research is regulated by the energetic sector with rules defined by the executive. Ancap evaluate the company proposals in relation of different topics such as drilling and processing, electromagnetism, sea floor sediments samples, oil well evidences and seismic information

  16. The microbial nitrogen cycling potential in marine sediments is impacted by polyaromatic hydrocarbon pollution

    Directory of Open Access Journals (Sweden)

    Nicole M Scott

    2014-03-01

    Full Text Available During petroleum hydrocarbon exposure the composition and functional dynamics of marine microbial communities are altered, favoring bacteria that can utilize this rich carbon source. Initial exposure of high levels of hydrocarbons in aerobic surface sediments can enrich growth of heterotrophic microorganisms having hydrocarbon degradation capacity. As a result, there can be a localized reduction in oxygen potential, if the sediments are aerobic, within the surface layer of marine sediments resulting in anaerobic zones. We hypothesized that increasing exposure to elevated hydrocarbon concentrations would positively correlate with an increase in denitrification processes and the net accumulation of dinitrogen. This hypothesis was tested by comparing the relative abundance of genes associated with nitrogen metabolism and nitrogen cycling identified in 6 metagenomes from sediments contaminated by polyaromatic hydrocarbons from the Deepwater Horizon oil spill in the Gulf of Mexico, and 3 metagenomes from sediments associated with natural oil seeps in the Santa Barbara Channel. An additional 8 metagenomes from uncontaminated sediments from the Gulf of Mexico were analyzed for comparison. We predicted relative changes in metabolite turnover as a function of the differential microbial gene abundances, which showed predicted accumulation of metabolites associated with denitrification processes, including anammox, in the contaminated samples compared to uncontaminated sediments, with the magnitude of this change being positively correlated to the hydrocarbon concentration and exposure duration. These data highlight the potential impact of hydrocarbon inputs on N cycling processes in marine sediments and provide information relevant for system scale models of nitrogen metabolism in affected ecosystems.

  17. Ignition behavior of aviation fuels and some hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Koerber, F.

    1975-01-01

    Air relighting of jet engines is an important contribution to the operation safety of aircraft engines. Reignition is influenced by fuel properties in addition to the engine design. A survey is presented on the problems, considering the specific fuel properties. Investigations were made on the ignition behavior of aviation fuels and hydrocarbons in a simplified model combustion chamber. Air inlet conditions were 200 to 800 mbar and 300 to 500 K. Correlation between physical and chemical properties and ignitability is discussed.

  18. Photodynamic activity of polycyclic hydrocarbon

    Energy Technology Data Exchange (ETDEWEB)

    Epstein, S S

    1963-01-01

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

  19. The pulsed migration of hydrocarbons across inactive faults

    Directory of Open Access Journals (Sweden)

    S. D. Harris

    1999-01-01

    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.

  20. Piston ring lubrication and hydrocarbon emissions from internal combustion engines

    Energy Technology Data Exchange (ETDEWEB)

    Froelund, K.

    1997-11-01

    Is it the intention with this project to improve the existing hydrocarbon emission model at the Institute by combining it with a model for predicting the piston ring lubrication. The piston ring lubrication model should be experimentally verified to ensure the validity of the model. The following items were the objectives of the current study: Develop a piston ring lubrication model. This implies the development of a ring-pack gas flow model; Examine the response of the piston ring lubrication model to changing engineer conditions. Especially, it would be interesting to look at the engine warm-up phase since this is the phase where the engine-out emissions are highest and where the commonly used three way catalyst is not capable of converting the engine-out emissions, thereby leading the engine-out emissions directly out in to the environment with the exhaust gases; In order to verify the piston ring lubrication model the lubricant distribution on the cylinder liner should be investigated experimentally. Here again it would be of great interesting to look at the engine warm-up phase; The piston ring lubrication model should be adjusted for application together with the new hydrocarbon emission model for SI-engines at the Institute in order to increase the accuracy of the latter; The piston ring lubrication model could be used for describing the transport of PAH`s in diesel engines. (EG)

  1. Technical evaluation summary of the in situ vitrification melt expulsion at the Oak Ridge National Laboratory on April 21, 1996, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    1996-07-01

    On April 21, 1996, at 6:12 PM, about 20 tons of molten glass were expelled from a 216-ton body of molten (1600 C) radioactively contaminated soil (containing 2.4 Ci 137 Cs) at an ORNL site. This was caused by pressurized steam venting rapidly through, rather than around, the molten body. During the previous 17 days, an old seepage pit was undergoing in situ vitrification to convert porous, leachable soil into an impermeable waste form. Analyses revealed that 0.13 μCi of 137 Cs could have been released and would have delivered a hypothetical, unmeasurable dose of 0.02 μrem to the nearest private residence outside the Oak Ridge Reservation. The expelled glass particles, having a uniform specific activity of 1.2E-08 Ci/g, contained no smearable or transferrable activity. Thus, the overall environmental impact was insignificant. Fire damage was completely limited to the off-gas hood. Techniques were identified to minimize the probability of future melt expulsions

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

    International Nuclear Information System (INIS)

    Roubal, G.; Atlas, R.M.

    1978-01-01

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

  3. Hydrocarbon pollution from marinas in estuarine sediments

    Science.gov (United States)

    Voudrias, Evangelos A.; Smith, Craig L.

    1986-03-01

    A measure of the impact of marinas on three Eastern Virginia estuarine creeks was obtained by a study of hydrocarbons in their sediments. Two of the creeks support considerable marine activity, including pleasure boat marinas, boat repair facilities, and commercial fishing operations. The third creek, which served as a control, is seldom used by boats, and is surrounded by marsh and woodland. Sediments from the creeks with marinas contained significantly higher levels of both aromatic and aliphatic hydrocarbons than did the control. Differences in the concentrations of certain oil-pollution indicators, such as the 17α,21β-hopane homologs and phytane, and low molecular weight aromatic hydrocarbons, are indicative of light petroleum fractions. Most of the aromatic hydrocarbons from all creeks, however, appear to have a pyrogenic origin. Although hydrocarbons from three probable origins (petroleum, pyrogenesis, and recent biosynthesis) were detected in all locations, the petroleum-derived and pyrogenic hydrocarbons were of only minor importance relative to the biogenic hydrocarbons in the control creek.

  4. Detection of irradiated meats by hydrocarbon method

    International Nuclear Information System (INIS)

    Goto, Michiko; Miyakawa, Hiroyuki; Fujinuma, Kenji; Ozawa, Hideki

    2005-01-01

    Meats, for example, lamb, razorback, wild duck and turkey were irradiated by gamma ray, and the amounts of hydrocarbons formed from fatty acids were measured. Since C 20:0 was found from wild duck and turkey. C 1-18:1 was recommended for internal standard. Good correlation was found between the amount of hydrocarbons and the doses of gamma irradiation. This study shows that such hydrocarbons induced after radiation procedure as C 1,7-16:2 , C 8-17:1 , C 1-14:1 , and C 15:0 may make it possible to detect irradiated lamb, razorback, wild duck and turkey. (author)

  5. Process for recovery of liquid hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Millar, J.F.; Cockshott, J.E.

    1978-04-11

    Methane is recovered as a gas for discharge to a pipeline from a gas stream containing methane and heavier hydrocarbons, principally ethane and propane. Separation is accomplished by condensing the heavier hydrocarbons and distilling the methane therefrom. A liquid product (LPG) comprising the heavier hydrocarbons is subsequently recovered and transferred to storage. Prior to being discharged to a pipeline, the recovered methane gas is compressed and in undergoing compression the gas is heated. The heat content of the gas is employed to reboil the refrigerant in an absorption refrigeration unit. The refrigeration unit is used to cool the LPG prior to its storage.

  6. Method of recovering hydrocarbons from oil shale

    Energy Technology Data Exchange (ETDEWEB)

    Walton, D.K.; Slusser, M.S.

    1970-11-24

    A method is described for recovering hydrocarbons from an oil-shale formation by in situ retorting. A well penetrating the formation is heated and gas is injected until a pressure buildup within the well is reached, due to a decrease in the conductivity of naturally occurring fissures within the formation. The well is then vented, in order to produce spalling of the walls. This results in the formation of an enlarged cavity containing rubberized oil shale. A hot gas then is passed through the rubberized oil shale in order to retort hydrocarbons and these hydrocarbons are recovered from the well. (11 claims)

  7. The offshore hydrocarbon releases (HCR) database

    International Nuclear Information System (INIS)

    Bruce, R.A.P.

    1995-01-01

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

  8. Waste Plastic Converting into Hydrocarbon Fuel Materials

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-09-15

    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.

  9. Conversion of hydrocarbon oils into motor fuels

    Energy Technology Data Exchange (ETDEWEB)

    1937-11-09

    The abstract describes a process for producing lower boiling hydrocarbon motor fuels with a starting material of wide boiling range composed primarily of hydrocarbon oils boiling substantially above the boiling range of the desired product. Separate catalytic and pyrolytic conversion zones are simultaneously maintained in an interdependent relationship. Higher boiling constituents are separated from residual constituents by fractionation while desirable reaction conditions are maintained. All or at least a portion of the products from the catalytic and pyrolytic conversion zones are blended to yield the desired lower boiling hydrocarbons or motor fuels.

  10. Algal Lipid Extraction and Upgrading to Hydrocarbons Technology Pathway

    Energy Technology Data Exchange (ETDEWEB)

    Davis, Ryan; Biddy, Mary J.; Jones, Susanne B.

    2013-03-31

    In support of the Bioenergy Technologies Office, the National Renewable Energy Laboratory (NREL) and the Pacific Northwest National Laboratory (PNNL) are undertaking studies of biomass conversion technologies to 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 technology pathway case investigates the cultivation of algal biomass followed by further lipid extraction and upgrading to hydrocarbon biofuels. Technical barriers and key research needs have been assessed in order for the algal lipid extraction and upgrading pathway to be competitive with petroleum-derived gasoline, diesel and jet range hydrocarbon blendstocks.

  11. Two-step processing of oil shale to linear hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Eliseev, O.L.; Ryzhov, A.N.; Latypova, D.Zh.; Lapidus, A.L. [Russian Academy of Sciences, Moscow (Russian Federation). N.D. Zelinsky Institute of Organic Chemistry; Avakyan, T.A. [Gubkin Russian State University of Oil and Gas, Moscow (Russian Federation)

    2013-11-01

    Thermal and catalytic steam reforming of oil shale mined from Leningrad and Kashpir deposits was studied. Experiments were performed in fixed bed reactor by varying temperature and steam flow rate. Data obtained were approximated by empirical formulas containing some parameters calculated by least-squares method. Thus predicting amount of hydrogen, carbon monoxide and methane in producer gas is possible for given particular kind of oil shale, temperature and steam flow rate. Adding Ni catalyst enriches hydrogen and depletes CO content in effluent gas at low gasification temperatures. Modeling gas simulating steam reforming gases (H{sub 2}, CO, CO{sub 2}, and N{sub 2} mixture) was tested in hydrocarbon synthesis over Co-containing supported catalyst. Selectivity of CO conversion into C{sub 5+} hydrocarbons reaches 84% while selectivity to methane is 7%. Molecular weight distribution of synthesized alkanes obeys Anderson-Schulz-Flory equation and chain growth probability 0.84. (orig.)

  12. Biological Conversion of Sugars to Hydrocarbons Technology Pathway

    Energy Technology Data Exchange (ETDEWEB)

    Davis, Ryan; Biddy, Mary J.; Tan, Eric; Tao, Ling; Jones, Susanne B.

    2013-03-31

    In support of the Bioenergy Technologies Office, the National Renewable Energy Laboratory (NREL) and the Pacific Northwest National Laboratory (PNNL) are undertaking studies of biomass conversion technologies to 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 technology pathway case investigates the biological conversion of biomass derived sugars to hydrocarbon biofuels, utilizing data from recent literature references and information consistent with recent pilot scale demonstrations at NREL. Technical barriers and key research needs have been identified that should be pursued for the pathway to become competitive with petroleum-derived gasoline, diesel and jet range hydrocarbon blendstocks.

  13. Seismic Evaluation of Hydrocarbon Saturation in Deep-Water Reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Michael Batzle

    2006-04-30

    During this last period of the ''Seismic Evaluation of Hydrocarbon Saturation in Deep-Water Reservoirs'' project (Grant/Cooperative Agreement DE-FC26-02NT15342), we finalized integration of rock physics, well log analysis, seismic processing, and forward modeling techniques. Most of the last quarter was spent combining the results from the principal investigators and come to some final conclusions about the project. Also much of the effort was directed towards technology transfer through the Direct Hydrocarbon Indicators mini-symposium at UH and through publications. As a result we have: (1) Tested a new method to directly invert reservoir properties, water saturation, Sw, and porosity from seismic AVO attributes; (2) Constrained the seismic response based on fluid and rock property correlations; (3) Reprocessed seismic data from Ursa field; (4) Compared thin layer property distributions and averaging on AVO response; (5) Related pressures and sorting effects on porosity and their influence on DHI's; (6) Examined and compared gas saturation effects for deep and shallow reservoirs; (7) Performed forward modeling using geobodies from deepwater outcrops; (8) Documented velocities for deepwater sediments; (9) Continued incorporating outcrop descriptive models in seismic forward models; (10) Held an open DHI symposium to present the final results of the project; (11) Relations between Sw, porosity, and AVO attributes; (12) Models of Complex, Layered Reservoirs; and (14) Technology transfer Several factors can contribute to limit our ability to extract accurate hydrocarbon saturations in deep water environments. Rock and fluid properties are one factor, since, for example, hydrocarbon properties will be considerably different with great depths (high pressure) when compared to shallow properties. Significant over pressure, on the other hand will make the rocks behave as if they were shallower. In addition to the physical properties, the scale and

  14. Radiolysis of hydrocarbons in liquid phase (Modern state of problem)

    International Nuclear Information System (INIS)

    Saraeva, V.V.

    1986-01-01

    Problems of ionizing radiation effect on hydrocarbons and hydrocarbon systems in a liquid phase are considered. Modern representations on the mechanism of hydrocarbon radiolysis are presented. Electron moderation and ion-electron pair formation, behaviour of charged particles, excited states, radical formation and their reactions are discussed. Behaviour of certain hydrocarbon classes: alkanes, cyclic hydrocarbons, olefines, aromatic hydrocarbons as well as different hydrocarbon mixtures is considered in detail. Radiation-chemical changes in organic coolants and ways of increasing radiation resistance are considered. Polyphenyl compounds are noted to be most perspective here

  15. Using microorganisms to aid in hydrocarbon degradation

    International Nuclear Information System (INIS)

    Black, W.; Zamora, J.

    1993-01-01

    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 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

  16. Volatilisation of aromatic hydrocarbons from soil

    DEFF Research Database (Denmark)

    Lindhardt, B.; Christensen, T.H.

    1996-01-01

    The non-steady-state fluxes of aromatic hydrocarbons were measured in the laboratory from the surface of soils contaminated with coal tar Four soil samples from a former gasworks site were used for the experiments. The fluxes were quantified for 11 selected compounds, 4 mono- and 7 polycyclic...... aromatic hydrocarbons, for a period of up to 8 or 16 days. The concentrations of the selected compounds in the soils were between 0.2 and 3,100 mu g/g. The study included the experimental determination of the distribution coefficient of the aromatic hydrocarbons between the sorbed phase and the water under...... saturated conditions. The determined distribution coefficients showed that the aromatic hydrocarbons were more strongly sorbed to the total organic carbon including the coal tar pitch - by a factor of 8 to 25 - than expected for natural organic matter. The fluxes were also estimated using an analytical...

  17. Recovering low-boiling hydrocarbons, etc

    Energy Technology Data Exchange (ETDEWEB)

    Pier, M

    1934-10-03

    A process is described for the recovery of low-boiling hydrocarbons of the nature of benzine through treatment of liquid carbonaceous materials with hydrogen under pressure at raised temperature, suitably in the presence of catalysts. Middle oils (practically saturated with hydrogen) or higher boiling oils at a temperature above 500/sup 0/ (with or without the addition of hydrogen) containing cyclic hydrocarbons not saturated with hydrogen are changed into low boiling hydrocarbons of the nature of benzine. The cracking takes place under strongly hydrogenating conditions (with the use of a strongly active hydrogenating catalyst or high pressure) at temperatures below 500/sup 0/. If necessary, the constituents boiling below 200/sup 0/ can be reconverted into cyclic hydrocarbons partially saturated with hydrogen. (BLM)

  18. Determination of polynuclear aromatic hydrocarbons (PAHs) in ...

    African Journals Online (AJOL)

    AJB SERVER

    2006-11-02

    Nov 2, 2006 ... Several water bodies in the Niger Delta region of Nigeria where extensive crude oil ..... hydrocarbons (PAHs) in fish from the Red Sea Coast of Yemem. ... smoked meat products and smoke flavouring food additives. J.

  19. Population dynamics and distribution of hydrocarbon utilizing ...

    African Journals Online (AJOL)

    Bacillus species was found to be present in all the soil samples analysed ... The presence of these organisms in soils contaminated with spent and unspent lubricating oil ... hydrocarbon utilizing bacteria, bioremediation, enrichment medium,

  20. Collision data involving hydro-carbon molecules

    International Nuclear Information System (INIS)

    Tawara, H.; Itikawa, Y.; Nishimura, H.; Tanaka, H.; Nakamura, Y.

    1990-07-01

    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)

  1. Study and modelling of deactivation by coke in catalytic reforming of hydrocarbons on Pt-Sn/Al{sub 2}O{sub 3} catalyst; La microbalance inertielle: etude et modelisation cinetique de la desactivation par le coke en reformage catalytique des hydrocarbures sur catalyseur Pt-Sn/Al{sub 2}O{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Mathieu-Deghais, S.

    2004-07-01

    Catalytic reforming is the refining process that produces gasoline with a high octane number. During a reforming operation, undesired side reactions promote the formation of carbon deposits (coke) on the surface of the catalyst. As the reactions proceed, the coke accumulation leads to a progressive decrease of the catalyst activity and to a change in its selectivity. Getting this phenomenon under control is interesting to optimize the industrial plants. This work aims to improve the comprehension and the modeling of coke formation and its deactivating effect on reforming reactions, while working under conditions chosen within a range as close as possible to the industrial conditions of the regenerative process. The experimental study is carried out with a micro unit that is designed to observe simultaneously the coke formation and its influence on the catalyst activity. A vibrational microbalance reactor (TEOM - Tapered Element Oscillating Microbalance) is used to provide continuous monitoring of coke. On-line gas chromatography is used to observe the catalyst activity and selectivity as a function of the coke content. The coking experiments are performed on a fresh Pt-Sn/alumina catalyst, with mixtures of hydrocarbon molecules of 7 carbon atoms as hydrocarbon feeds. The coking tests permitted to highlight the operating parameters that may affect the amount of coke, and to identify the hydrocarbon molecules that behave as coke intermediate. A kinetic model for coke formation could be developed through the compilation of these results. The catalytic activity analysis permitted to point out the coke effect on both of the active phases of the catalyst, to construct a simplified reforming kinetic model that simulates the catalyst activity under the reforming conditions, and to quantify deactivation via deactivation functions. (author)

  2. Preliminary Economics for Hydrocarbon Fuel Production from Cellulosic Sugars

    Energy Technology Data Exchange (ETDEWEB)

    Collett, James R.; Meyer, Pimphan A.; Jones, Susanne B.

    2014-05-18

    Biorefinery process and economic models built in CHEMCAD and a preliminary, genome-scale metabolic model for the oleaginous yeast Lipomyces starkeyi were used to simulate the bioconversion of corn stover to lipids, and the upgrading of these hydrocarbon precursors to diesel and jet fuel. The metabolic model was based on the recently released genome sequence for L. starkeyi and on metabolic pathway information from the literature. The process model was based on bioconversion, lipid extraction, and lipid oil upgrading data found in literature, on new laboratory experimental data, and on yield predictions from the preliminary L. starkeyi metabolic model. The current plant gate production cost for a distillate-range hydrocarbon fuel was estimated by the process model Base Case to be $9.5/gallon ($9.0 /gallon of gasoline equivalent) with assumptions of 2011$, 10% internal return on investment, and 2205 ton/day dry feed rate. Opportunities for reducing the cost to below $5.0/gallon, such as improving bioconversion lipid yield and hydrogenation catalyst selectivity, are presented in a Target Case. The process and economic models developed for this work will be updated in 2014 with new experimental data and predictions from a refined metabolic network model for L. starkeyi. Attaining a production cost of $3.0/gallon will require finding higher value uses for lignin other than power generation, such as conversion to additional fuel or to a co-product.

  3. Zeolitic catalytic conversion of alcohols to hydrocarbons

    Science.gov (United States)

    Narula, Chaitanya K.; Davison, Brian H.; Keller, Martin

    2018-04-10

    A method for converting an alcohol to a hydrocarbon, the method comprising contacting said alcohol with a metal-loaded zeolite catalyst at a temperature of at least 100.degree. C. and up to 550.degree. C., wherein said alcohol can be produced by a fermentation process, said metal is a positively-charged metal ion, and said metal-loaded zeolite catalyst is catalytically active for converting said alcohol to said hydrocarbon.

  4. Formation of hydrocarbons by bacteria and algae

    Energy Technology Data Exchange (ETDEWEB)

    Tornabene, T.G.

    1980-12-01

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

  5. Nitrocarburizing in ammonia-hydrocarbon gas mixtures

    DEFF Research Database (Denmark)

    Pedersen, Hanne; Christiansen, Thomas; Somers, Marcel A. J.

    2011-01-01

    The present work investigates the possibility of nitrocarburising in ammonia-acetylene-hydrogen and ammonia-propene-hydrogen gas mixtures, where unsaturated hydrocarbon gas is the carbon source during nitrocarburising. Consequently, nitrocarburising is carried out in a reducing atmosphere...... microscopy and X-ray diffraction analysis. It is shown that the use of unsaturated hydrocarbon gas in nitrocarburising processes is a viable alternative to traditional nitrocarburising methods....

  6. Nitrocarburising in ammonia-hydrocarbon gas mixtures

    DEFF Research Database (Denmark)

    Pedersen, Hanne; Christiansen, Thomas; Somers, Marcel A. J.

    2010-01-01

    The present work investigates the possibility of nitrocarburising in ammonia-acetylene-hydrogen and ammoniapropene- hydrogen gas mixtures, where unsaturated hydrocarbon gas is the carbon source during nitrocarburising. Consequently, nitrocarburising is carried out in a reducing atmosphere...... microscopy and X-ray diffraction analysis. It is shown that the use of unsaturated hydrocarbon gas in nitrocarburising processes is a viable alternative to traditional nitrocarburising methods....

  7. The future of oil and hydrocarbon man

    CERN Document Server

    Campbell, Colin

    1999-01-01

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

  8. Zeolitic catalytic conversion of alochols to hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Narula, Chaitanya K.; Davison, Brian H.; Keller, Martin

    2017-01-03

    A method for converting an alcohol to a hydrocarbon, the method comprising contacting said alcohol with a metal-loaded zeolite catalyst at a temperature of at least 100.degree. C. and up to 550.degree. C., wherein said alcohol can be produced by a fermentation process, said metal is a positively-charged metal ion, and said metal-loaded zeolite catalyst is catalytically active for converting said alcohol to said hydrocarbon.

  9. Birds and polycyclic aromatic hydrocarbons

    Science.gov (United States)

    Albers, P.H.

    2006-01-01

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

  10. PROTONATED POLYCYCLIC AROMATIC HYDROCARBONS REVISITED

    International Nuclear Information System (INIS)

    Ricca, Alessandra; Bauschlicher, Charles W. Jr; Allamandola, Louis J.

    2011-01-01

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

  11. Polycyclic hydrocarbons - occurrence and determination

    International Nuclear Information System (INIS)

    Drzewicz, P.

    2007-01-01

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

  12. Dewaxing hydrocarbon oils. [British patent

    Energy Technology Data Exchange (ETDEWEB)

    1933-06-23

    In dewaxing hydrocarbon oils such as residium stocks, overhead distillates and crude petroleum or shale oils, by admixing with a liquefied normally gaseous solvent, such as liquefied propane, and cooling to crystallize the wax, the rate of crystallization diminishes rapidly when a certain temperature in an example about 20/sup 0/F is reached. The diminution is prevented during further cooling by removing solvent by evaporation at such a rate that the proporation of solvent in the oil solvent component is maintained at about that existing at the temperature at which the alteration in the rate of crystallization takes place. The evaporation is effected by adjusting the pressure on the mixture, preferably in stages. Solvents for coloring matters and asphaltic compounds, such as carbon disulfide sulfur dioxide, methyl chloride or butyl alcohol may be added to the mixture before crystallization. Chilled solvent may be added to the chilled mixture before separation of the wax in a centrifuge, in order to increase the difference in specific gravity between the wax and the oil-solvent component.

  13. Behaviour of polycyclic aromatic hydrocarbons (PAH) in soils under freeze-thaw cycles

    Science.gov (United States)

    Zschocke, Anne; Schönborn, Maike; Eschenbach, Annette

    2010-05-01

    the frozen part of the column. However these results were not statistically significant they could proof results from Chuvilin et al. (2001). Who found similar results in sandy and clayey material and presumed the expulsion of petroleum hydrocarbons. Barnes et al. (2004) specified that the exclusion of petroleum hydrocarbons due to freezing is caused by displacement from the pore spaces due to expansion of the ice and the forming of crystalline ice structure. Further experimental approaches to investigate the effect of freezing and thawing of permafrost influenced soils on PAH migration will be discussed. References: Barnes, D. L.; Wolfe, S. M. & Filler, D. M. (2004): Equilibrium distribution of petroleum hydrocarbons in freezing ground, Polar Record, 40, 245-251. Börresen M.H., Barnes D.L., Rike A.G. (2007): Repeated freeze-thaw cycles and their effects on mineralization of hexadecane and phenanthrene in cold climate soils. Cold Regions Science and Technology 49, 215-225. Chuvilin, E.; Naletova, N.; Miklyaeva, E.; Kozlova, E. & Instanes, A. (2001): Factors affecting spreadability and transportation of oil in regions of frozen ground. Polar Record 37, 229-238. Curtosi, A.; Pelletier, E.; Vodopivez, C.L.; Mac Cormack, W.P. (2007): Polycyclic aromatic hydrocarbons in soil and surface marine sediment near Jubany Station (Antarctica). Role of permafrost as a low-permeability barrier. Science of The Total Environment 383, 1-3, 193-204. Eschenbach, A.; Wienberg, R.; Mahro, B. (2000): Formation, long-term stability and fate of non-extractable 14C-PAH-residues in contaminated soils. In: Wise, D.L.; Trantolo, D.J.; Cichon, E.J.; Inyang, H.J.; Stottmeister, U. (eds): Remediation Engineering of Contaminated Soils, 2nd Edition; Marcel-Dekker, New York, p. 427-446.

  14. Biodegradation of petroleum hydrocarbons at low temperatures

    International Nuclear Information System (INIS)

    Whyte, L. G.; Greer, C W.

    1999-01-01

    Bioremediation of contaminated Arctic sites has been proposed as the logistically and economically most favorable solution despite the known technical difficulties. The difficulties involve the inhibition of pollutants removal by biodegradation below freezing temperatures and the relative slowness of the process to remove enough hydrocarbon pollutants during the above-freezing summer months. Despite these formidable drawbacks, biodegradation of hydrocarbon contaminants is possible even in below-zero temperatures, especially if indigenous psychrophilic and psychrotropic micro-organism are used. This paper reports results of a study involving several hydrocarbon-degrading psychrotropic bacteria and suggests bioaugmentation with specific cold-adapted organisms and/or biostimulation with commercial fertilizers for enhancing degradation of specific contaminants in soils from northern Canada. An evaluation of the biodegradation potential of hydrocarbon contaminated soils in the high Arctic suggested that the contaminated soils contained sufficient numbers of cold-adapted hydrocarbon-degrading bacteria and that the addition of fertilizer was sufficient to enhance the level of hydrocarbon degradation at low ambient summer temperatures. 9 refs., 2 tabs., 3 figs

  15. Improved Detection and Mapping of Deepwater Hydrocarbon Seeps: Optimizing Acquisition and Processing Parameters for Marine Seep Hunting

    Science.gov (United States)

    Mitchell, G. A.; Orange, D.; Gharib, J. J.; Saade, E. J.; Joye, S. B.

    2016-12-01

    Marine seep hunting surveys are a current focus of hydrocarbon exploration due to recent advances in offshore geophysical and geochemical technologies. Hydrocarbon seeps are ephemeral, small, discrete, and often difficult to sample on the deep seafloor. Low to mid-frequency multibeam echosounders (MBES) are an ideal exploration tool to remotely locate and map seafloor features associated with seepage. Geophysical signatures from hydrocarbon seeps are evident in bathymetric datasets (fluid expulsion features), seafloor backscatter datasets (carbonate outcrops, gassy sediments, methane hydrate deposits), and midwater backscatter datasets (gas bubble and oil droplet plumes). Interpretation of these geophysical seep signatures in backscatter datasets is a fundamental component in seep hunting. Degradation of backscatter datasets resulting from environmental, geometric, and system noise can interfere with the detection and delineation of seeps. We present a backscatter intensity normalization method and a 2X acquisition technique that can enhance the geologic resolvability within backscatter datasets and assist in interpretation and characterization of seeps. We use GC600 in the Northern Gulf of Mexico as a seep calibration site for a Kongsberg EM302 30 kHz MBES prior to the start of the Gigante seep hunting survey. We analyze the results of a backscatter intensity normalization, assess the effectiveness of 2X seafloor coverage in resolving geologic features in backscatter data, and determine off-nadir detection limits of bubble plumes. GC600's location and robust venting make it a natural laboratory in which to study natural hydrocarbon seepage. The site has been the focus of several near-seafloor surveys as well as in-situ studies using advanced deepwater technologies analyzing fluid flux and composition. These datasets allow for ground-truthing of our remote backscatter measurements prior to commencing exploration within the frontier regions of the Southern Gulf of

  16. Leaf swallowing and parasite expulsion in Khao Yai white-handed gibbons (Hylobates lar), the first report in an Asian ape species.

    Science.gov (United States)

    Barelli, Claudia; Huffman, Michael A

    2017-03-01

    Leaf swallowing behavior, known as a form of self-medication for the control of nematode and tapeworm infection, occurs widely in all the African great apes (Pan troglodytes schweinfurthii, P. t. troglodytes, P. t. verus, P. t. vellerosus, Pan paniscus, Gorilla gorilla graueri), except mountain gorillas. It is also reported to occur in a similar context across a wide array of other animal taxa including, domestic dogs, wolves, brown bears, and civets. Despite long-term research on Asian great and small apes, this is the first report of leaf swallowing in an Asian species, the white-handed gibbon (Hylobates lar) in Khao Yai National Park, central Thailand. We present the first evidence of leaf swallowing (Gironniera nervosa Planch CANNABACEA) behavior (N = 5 cases) and parasite (Streptopharagus pigmentatus) expulsion (N = 4 cases), recorded during 4,300 hr of direct animal observations during two distinct research projects. We recovered 4-18 rough, hairy, and hispid surfaced leaves from each sample, undigested and folded, from the freshly evacuated feces of five different individuals (2 males, 3 females, 5 to 34+ years old) living in three different social groups, between the hours of 06:00 to 10:30. Based on close inspection of the leaves, as observed in chimpanzees, it was clear that they were taken into the mouth, one at a time, folded and detached from the stem with the teeth before swallowing them whole. All instances occurred during the rainy season, the time when nematode worms were also found in the feces, although they were not found together with leaves in the same feces. These striking similarities in the details of leaf swallowing between white-handed gibbons and African great apes, and other animal species, suggest a similar self-medicative function. © 2016 Wiley Periodicals, Inc.

  17. Using maya chair during the expulsive phase of delivery and its relation to the lower incidence of episiotomy or perineal tears

    Directory of Open Access Journals (Sweden)

    Laura López Quirós

    2014-04-01

    Full Text Available The aims of this article is to present the results obtained from the development of a clinical question about using maya obstetric chair during the expulsive phase of delivery and its relation to the lower incidence of episiotomy and perineal tears. In traditional cultures, the women give birth naturally in vertical positions as kneeling, standing, among others. In Western societies, physicians have influenced women will deliver in the supine position, sometimes with legs raised using stirrups. For women of our country is difficult to adopt "alternative" positions that have traditionally been seen as 'normal'. The maya chair is used in the countries of South America, and it appears to be an effective way to prevent perineal tears and the lower incidence of episiotomy duringchildbirth. To carry out this secondary research methodology for clinical practice based on evidence that consists of five steps was used. A question was developed in PICO format (patient, intervention, comparison and observation, then an information search was performed in different databases like Ebsco Host, Google Scholar, PubMed, Medline plus, Embase. 30 articles were found, were analyzed according to the criteria set FCL version 2.0, of which only one was close to answering the clinical question. Information was socialized in a formalpresentation by CIEBE-CR. It is conclude that there is insufficient evidence that the use of maya chair during theexpulsive phase of delivery significantly reduces the risk of perianal tear and lower incidence of episiotomy.

  18. Study of liquid hydrocarbons subjected to ionizing radiations

    International Nuclear Information System (INIS)

    Grob, Robert.

    1977-01-01

    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 α 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 [fr

  19. Hydrocarbon analysis using desorption atmospheric pressure chemical ionization

    KAUST Repository

    Jjunju, Fred Paul Mark; Badu-Tawiah, Abraham K.; Li, Anyin; Soparawalla, Santosh; Roqan, Iman S.; Cooks, Robert Graham

    2013-01-01

    Characterization of the various petroleum constituents (hydronaphthalenes, thiophenes, alkyl substituted benzenes, pyridines, fluorenes, and polycyclic aromatic hydrocarbons) was achieved under ambient conditions without sample preparation by desorption atmospheric pressure chemical ionization (DAPCI). Conditions were chosen for the DAPCI experiments to control whether ionization was by proton or electron transfer. The protonated molecule [M+H]+ and the hydride abstracted [MH]+ form were observed when using an inert gas, typically nitrogen, to direct a lightly ionized plasma generated by corona discharge onto the sample surface in air. The abundant water cluster ions generated in this experiment react with condensed-phase functionalized hydrocarbon model compounds and their mixtures at or near the sample surface. On the other hand, when naphthalene was doped into the DAPCI gas stream, its radical cation served as a charge exchange reagent, yielding molecular radical cations (M+) of the hydrocarbons. This mode of sample ionization provided mass spectra with better signal/noise ratios and without unwanted side-products. It also extended the applicability of DAPCI to petroleum constituents which could not be analyzed through proton transfer (e.g., higher molecular PAHs such as chrysene). The thermochemistry governing the individual ionization processes is discussed and a desorption/ionization mechanism is inferred. © 2012 Elsevier B.V.

  20. Microplasma reforming of hydrocarbons for fuel cell power

    Science.gov (United States)

    Besser, R. S.; Lindner, P. J.

    The implementation of a microplasma approach for small scale reforming processes is explored as an alternative to more standard catalyst-based processes. Plasmas are a known approach to activating a chemical reaction in place of catalysts, and microplasmas are particularly attractive owing to their extremely high electron and power densities. Their inherent compactness gives them appeal for portable applications, but their modularity leads to scalability for higher capacity. We describe the realization of experimental microplasma reactors based on the microhollow cathode discharge (MHCD) structure by silicon micromachining for device fabrication. Experiments were carried out with model hydrocarbons methane and butane in the reactors within a microfluidic flow and analytical setup. We observe several key phenomena, including the ability to liberate hydrogen from the hydrocarbons at temperatures near ambient and sub-Watt input power levels, the tendency toward hydrocarbon decomposition rather than oxidation even in the presence of oxygen, and the need for a neutral carrier to obtain conversion. Mass and energy balances on these experiments revealed conversions up to nearly 50%, but the conversion of electrical power input to chemical reaction enthalpy was only on the order of 1%. These initial, exploratory results were recorded with devices and at process settings without optimization, and are hence promising for an emerging, catalyst-free reforming approach.

  1. Hydrocarbon analysis using desorption atmospheric pressure chemical ionization

    KAUST Repository

    Jjunju, Fred Paul Mark

    2013-07-01

    Characterization of the various petroleum constituents (hydronaphthalenes, thiophenes, alkyl substituted benzenes, pyridines, fluorenes, and polycyclic aromatic hydrocarbons) was achieved under ambient conditions without sample preparation by desorption atmospheric pressure chemical ionization (DAPCI). Conditions were chosen for the DAPCI experiments to control whether ionization was by proton or electron transfer. The protonated molecule [M+H]+ and the hydride abstracted [MH]+ form were observed when using an inert gas, typically nitrogen, to direct a lightly ionized plasma generated by corona discharge onto the sample surface in air. The abundant water cluster ions generated in this experiment react with condensed-phase functionalized hydrocarbon model compounds and their mixtures at or near the sample surface. On the other hand, when naphthalene was doped into the DAPCI gas stream, its radical cation served as a charge exchange reagent, yielding molecular radical cations (M+) of the hydrocarbons. This mode of sample ionization provided mass spectra with better signal/noise ratios and without unwanted side-products. It also extended the applicability of DAPCI to petroleum constituents which could not be analyzed through proton transfer (e.g., higher molecular PAHs such as chrysene). The thermochemistry governing the individual ionization processes is discussed and a desorption/ionization mechanism is inferred. © 2012 Elsevier B.V.

  2. Chemical deactivation of Ag/Al2O3 by sulphur for the selective reduction of NOx using hydrocarbons

    International Nuclear Information System (INIS)

    Houel, Valerie; Millington, Paul; Pollington, Stephen; Poulston, Stephen; Rajaram, Raj R.; Tsolakis, Athanasios

    2006-01-01

    The hydrocarbon-SCR activity of Ag/Al 2 O 3 catalysts is severely deactivated after low temperature (350 o C) sulphur ageing in the form of SO 2 exposure. Catalysts aged with SO 2 , NO and hydrocarbon present accumulate a significantly larger amount of SO 4 2- than those aged in the presence of only O 2 , H 2 O and SO 2 when exposed to an equivalent amount of S. Following sulphation of the catalyst most of the sulphur can be removed by a high temperature (600 o C) treatment in the reaction gas. Regeneration in the absence of hydrocarbon is ineffective. The hydrocarbon-SCR activity of the sulphated catalyst using model hydrocarbons such as n-C 8 H 18 can be restored after a high temperature pre-treatment in the reaction gases. However this desulphation process fails to regenerate the hydrocarbon-SCR activity when diesel fuel is used in the activity test. TPR studies show that a major fraction of the sulphur species present in the catalyst is removed by such pre-treatment, but the slight residual amount of sulphur is sufficient to inhibit the activation of the diesel fuel on the Ag catalyst. The nature of the hydrocarbon species present for the hydrocarbon-SCR reaction and during the regeneration strongly influences the activity. In general aromatics such as C 7 H 8 are less effective for reducing NO x and regenerating the sulphated catalyst. (author)

  3. Enhanced characterization of reservoir hydrocarbon components using electromagnetic data attributes

    KAUST Repository

    Katterbauer, Klemens

    2015-12-23

    Advances in electromagnetic imaging techniques have led to the growing utilization of this technology for reservoir monitoring and exploration. These exploit the strong conductivity contrast between the hydrocarbon and water phases and have been used for mapping water front propagation in hydrocarbon reservoirs and enhancing the characterization of the reservoir formation. The conventional approach for the integration of electromagnetic data is to invert the data for saturation properties and then subsequently use the inverted properties as constraints in the history matching process. The non-uniqueness and measurement errors may however make this electromagnetic inversion problem strongly ill-posed, leading to potentially inaccurate saturation profiles. Another limitation of this approach is the uncertainty of Archie\\'s parameters in relating rock conductivity to water saturation, which may vary in the reservoir and are generally poorly known. We present an Ensemble Kalman Filter framework for efficiently integrating electromagnetic data into the history matching process and for simultaneously estimating the Archie\\'s parameters and the variance of the observation error of the electromagnetic data. We apply the proposed framework to a compositional reservoir model. We aim at assessing the relevance of EM data for estimating the different hydrocarbon components of the reservoir. The experimental results demonstrate that the individual hydrocarbon components are generally well matched, with nitrogen exhibiting the strongest improvement. The estimated observation error standard deviations are also within expected levels (between 5 and 10%), significantly contributing to the robustness of the proposed EM history matching framework. Archie\\'s parameter estimates approximate well the reference profile and assist in the accurate description of the electrical conductivity properties of the reservoir formation, hence leading to estimation accuracy improvements of around

  4. Enhanced characterization of reservoir hydrocarbon components using electromagnetic data attributes

    KAUST Repository

    Katterbauer, Klemens; Arango, Santiago; Sun, Shuyu; Hoteit, Ibrahim

    2015-01-01

    Advances in electromagnetic imaging techniques have led to the growing utilization of this technology for reservoir monitoring and exploration. These exploit the strong conductivity contrast between the hydrocarbon and water phases and have been used for mapping water front propagation in hydrocarbon reservoirs and enhancing the characterization of the reservoir formation. The conventional approach for the integration of electromagnetic data is to invert the data for saturation properties and then subsequently use the inverted properties as constraints in the history matching process. The non-uniqueness and measurement errors may however make this electromagnetic inversion problem strongly ill-posed, leading to potentially inaccurate saturation profiles. Another limitation of this approach is the uncertainty of Archie's parameters in relating rock conductivity to water saturation, which may vary in the reservoir and are generally poorly known. We present an Ensemble Kalman Filter framework for efficiently integrating electromagnetic data into the history matching process and for simultaneously estimating the Archie's parameters and the variance of the observation error of the electromagnetic data. We apply the proposed framework to a compositional reservoir model. We aim at assessing the relevance of EM data for estimating the different hydrocarbon components of the reservoir. The experimental results demonstrate that the individual hydrocarbon components are generally well matched, with nitrogen exhibiting the strongest improvement. The estimated observation error standard deviations are also within expected levels (between 5 and 10%), significantly contributing to the robustness of the proposed EM history matching framework. Archie's parameter estimates approximate well the reference profile and assist in the accurate description of the electrical conductivity properties of the reservoir formation, hence leading to estimation accuracy improvements of around 15%.

  5. Upgrading of syngas hydrotreated fractionated oxidized bio-oil to transportation grade hydrocarbons

    International Nuclear Information System (INIS)

    Luo, Yan; Hassan, El Barbary; Guda, Vamshi; Wijayapala, Rangana; Steele, Philip H.

    2016-01-01

    Highlights: • Hydrotreating of fractionated oxidized bio-oil with syngas was feasible. • Hydrocarbon properties were similar with all syngas H_2/CO molar ratios except viscosity. • Syngas with H_2/CO molar ratio of (4:6) produced the highest hydrocarbon yield. • The produced hydrocarbons were in the range of gasoline, jet fuel and diesel boiling points. - Abstract: Fast pyrolysis bio-oils have the potential to replace a part of transportation fuels obtained from fossil. Bio-oil can be successfully upgraded into stable hydrocarbons (gasoline, jet fuel and diesel) through a two-stage hydrodeoxygenation process. Consumption large amount of expensive hydrogen during this process is the major hurdle for commercialization of this technology. Applying syngas in the hydrotreating step can significantly reduce the cost of the whole process and make it competitive. In this study, four different models of syngas with different H_2 concentrations (H_2/CO molar ratios = 2:8, 4:6, 6:4 and 8:2) were used for the 1st-stage hydrotreating step of oxidized fractionated bio-oil (OFB). The 2nd-stage hydrocracking step was performed on the produced organic liquid products (OLPs) by using pure H_2 gas. The effect of syngas H_2 concentrations on the yields and properties of OLPs and the 2nd-stage hydrocarbons (HCs) was investigated. Physical and chemical properties of the 2nd-stage hydrocarbons were similar regardless syngas H_2 content, with the exception of the viscosity. Syngas with H_2/CO molar ratio of 4:6 gave significantly highest HCs yield (24.8 wt.%) based on the OFB. Simulated distillation analysis proved that all 2nd-stage hydrocarbons were mixture from a wide range boiling point fuels. These results also indicated that the successful 1st-stage syngas hydrotreating step was having the potential to produce different hydrocarbons.

  6. Heterogeneous OH oxidation of motor oil particles causes selective depletion of branched and less cyclic hydrocarbons.

    Science.gov (United States)

    Isaacman, Gabriel; Chan, Arthur W H; Nah, Theodora; Worton, David R; Ruehl, Chris R; Wilson, Kevin R; Goldstein, Allen H

    2012-10-02

    Motor oil serves as a useful model system for atmospheric oxidation of hydrocarbon mixtures typical of anthropogenic atmospheric particulate matter, but its complexity often prevents comprehensive chemical speciation. In this work we fully characterize this formerly "unresolved complex mixture" at the molecular level using recently developed soft ionization gas chromatography techniques. Nucleated motor oil particles are oxidized in a flow tube reactor to investigate the relative reaction rates of observed hydrocarbon classes: alkanes, cycloalkanes, bicycloalkanes, tricycloalkanes, and steranes. Oxidation of hydrocarbons in a complex aerosol is found to be efficient, with approximately three-quarters (0.72 ± 0.06) of OH collisions yielding a reaction. Reaction rates of individual hydrocarbons are structurally dependent: compared to normal alkanes, reaction rates increased by 20-50% with branching, while rates decreased ∼20% per nonaromatic ring present. These differences in rates are expected to alter particle composition as a function of oxidation, with depletion of branched and enrichment of cyclic hydrocarbons. Due to this expected shift toward ring-opening reactions heterogeneous oxidation of the unreacted hydrocarbon mixture is less likely to proceed through fragmentation pathways in more oxidized particles. Based on the observed oxidation-induced changes in composition, isomer-resolved analysis has potential utility for determining the photochemical age of atmospheric particulate matter with respect to heterogeneous oxidation.

  7. Development changes of cuticular hydrocarbons in Chrysomya rufifacies larvae: potential for determining larval age.

    Science.gov (United States)

    Zhu, G H; Ye, G Y; Hu, C; Xu, X H; Li, K

    2006-12-01

    Age determination is the basis of determining the postmortem interval using necrophagous fly larvae. To explore the potential of using cuticular hydrocarbons for determining the ages of fly larvae, changes of cuticular hydrocarbons in developing larvae of Chrysomya rufifacies (Macquart) (Diptera: Calliphoridae) were investigated using gas chromatography with flame-ionization detection and gas chromatography-mass spectrometry. This study showed that the larvae produced cuticular hydrocarbons typical of insects. Most of the hydrocarbons identified were alkanes with the carbon chain length of 21-31, plus six kinds of alkenes. The hydrocarbon composition of the larvae correlated with age. The statistical results showed that simple peak ratios of n-C29 divided by another eight selected peaks increased significantly with age; their relationships with age could be modelled using exponential or power functions with R(2) close to or > 0.80. These results suggest that cuticular hydrocarbon composition is a useful indicator for determining the age of larval C. rufifacies, especially for post-feeding larvae, which are difficult to differentiate by morphology.

  8. A method for predicting the extent of petroleum hydrocarbon biodegradation in contaminated soils

    International Nuclear Information System (INIS)

    Huesemann, M.H.

    1994-01-01

    A series of solid- and slurry-phase soil bioremediation experiments involving different crude oils and refined petroleum products were performed to investigate the factors which affect the maximum extent of total petroleum hydrocarbon (TPH) biodegradation. The authors used a comprehensive petroleum hydrocarbon characterization procedure involving group-type separation analyses, boiling-point distributions, and hydrocarbon typing by field ionization mass spectroscopy. Initial and final concentrations of specified hydrocarbon classes were determined in each of seven different bioremediation treatments. Generally, they found that the degree of TPH biodegradation was affected mainly by the type of hydrocarbons in the contaminant matrix. In contrast, the influence of experimental variables such as soil type, fertilizer concentrations, microbial plate counts, and treatment type (slurry versus landfarming) on the overall extent of TPH biodegradation was insignificant. Based on these findings, a predictive algorithm was developed to estimate the extent of TPH biodegradation from the average reduction of 86 individual hydrocarbon classes and their respective initial concentrations. Model predictions for gravimetric TPH removals were in close agreement with analytical results from two independent laboratories

  9. Adaptive immunity alters distinct host feeding pathways during nematode induced inflammation, a novel mechanism in parasite expulsion.

    Directory of Open Access Journals (Sweden)

    John J Worthington

    2013-01-01

    Full Text Available Gastrointestinal infection is often associated with hypophagia and weight loss; however, the precise mechanisms governing these responses remain poorly defined. Furthermore, the possibility that alterations in feeding during infection may be beneficial to the host requires further study. We used the nematode Trichinella spiralis, which transiently inhabits the small intestine before migrating to skeletal muscle, as a biphasic model of infection to determine the cellular and molecular pathways controlling feeding during enteric and peripheral inflammation. Through the infection of genetically modified mice lacking cholecystokinin, Tumor necrosis factor α receptors and T and B-cells, we observed a biphasic hypophagic response to infection resulting from two separate immune-driven mechanisms. The enteroendocrine I-cell derived hormone cholecystokinin is an essential mediator of initial hypophagia and is induced by CD4+ T-cells during enteritis. In contrast, the second hypophagic response is extra-intestinal and due to the anorectic effects of TNFα during peripheral infection of the muscle. Moreover, via maintaining naive levels of the adipose secreted hormone leptin throughout infection we demonstrate a novel feedback loop in the immunoendocrine axis. Immune driven I-cell hyperplasia and resultant weight loss leads to a reduction in the inflammatory adipokine leptin, which in turn heightens protective immunity during infection. These results characterize specific immune mediated mechanisms which reduce feeding during intestinal or peripheral inflammation. Importantly, the molecular mediators of each phase are entirely separate. The data also introduce the first evidence that I-cell hyperplasia is an adaptively driven immune response that directly impinges on the outcome to infection.

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

    International Nuclear Information System (INIS)

    Perez, M.; Gonzalez, D.

    1988-01-01

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

  11. Impact of rock salt creep law choice on subsidence calculations for hydrocarbon reservoirs overlain by evaporite caprocks

    NARCIS (Netherlands)

    Marketos, G.; Spiers, C.J.; Govers, R.

    2016-01-01

    Accurate forward modeling of surface subsidence above producing hydrocarbons reservoirs requires an understanding of the mechanisms determining how ground deformation and subsidence evolve. Here we focus entirely on rock salt, which overlies a large number of reservoirs worldwide, and specifically

  12. Active hydrocarbon (methane) seepage at the Alboran Sea mud volcanoes indicated by specific lipid biomarkers.

    Science.gov (United States)

    Lopez-Rodriguez, C.; Stadnitskaia, A.; De Lange, G. J.; Martínez-Ruiz, F.; Comas, M.; Sinninghe Damsté, J. S.

    2012-04-01

    Mud volcanoes (MVs) and pockmark fields are known to occur in the Alboran Basin (Westernmost Mediterranean). These MVs occur above a major sedimentary depocenter that includes up to 7 km thick early Miocene to Holocene sequences. MVs located on the top of diapiric structures that originated from undercompacted Miocene clays and olistostromes. Here we provide results from geochemical data-analyses of four gravity cores acquired in the Northern Mud Volcano Field (north of the 36°N): i.e. Perejil, Kalinin and Schneiderś Heart mud expulsion structures. Extruded materials include different types of mud breccias. Specific lipid biomarkers (n-alkanes, hopanes, irregular isoprenoid hydrocarbons and Dialkyl Glycerol Diethers (DGDs) were analysed by gas chromatography (GC) and gas chromatography mass spectrometry (GC-MS). Determination of Glycerol Dialkyl Glycerol Tetraethers (GDGTs) by high performance liquid chromatography-spectrometry (HPLC-MS), and analysis of biomarker δ13C values were performed in selected samples. Lipid biomarker analysis from the three MVs revealed similar n-alkane distributions in all mud breccia intervals, showing significant hydrocarbon-derived signals and the presence of thermally immature organic-matter admixture. This suggests that similar strata fed these MVs. The hemipelagic drapes reveal comparable n-alkane distributions, suggesting that significant upward diffusion of fluids occurs. Distributions of GDGTs are generally accepted as usefull biomarkers to locate the anaerobic oxidation of methane (AOM) in marine sediments. However, our GDGT profiles only reflect the marine thaumarchaeotal signature. There seems to be no archaea producing specific GDGTs involved in AOM in the recovered interval. Evidence of recent activity (i.e., methane gas-bubbling and chemosynthetic fauna at the Perejil MV) and the presence of specific lipid biomarker related with methanotropic archaea (Irregular Isoprenoids and DGDs), however, suggest the existence of

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

    International Nuclear Information System (INIS)

    Zheng, G.J.; Richardson, B.J.

    1999-01-01

    A total of 20 surficial sediment samples, obtained from Hong Kong coastal waters, were analysed for petroleum hydrocarbons (PHCs) and a suite of 15 polycyclic aromatic hydrocarbons (PAHs). The results indicate that Hong Kong coastal sediments are often seriously polluted with petroleum related hydrocarbons. This is especially so in heavily urbanised or industrialized localities, such as Kowloon Bay (Victoria Harbour), Tsing Yi North and Tolo Harbour. Petroleum hydrocarbon pollutants in marine sediments are believed to be mainly derived from the transportation of oil, shipping activities, spillages, and industrial, stormwater and waste wastewater discharge. The ratio of unresolved complex mixture (UCM) to n-alkanes, carbon preference index (CPI), and n-C 16 values indicate that the main contribution to petroleum hydrocarbon contamination is via oil and its products. Pollutant sources appear to be stable and continuing when compared with previous data. (author)

  14. Inhibition of the aryl hydrocarbon receptor prevents Western diet-induced obesity. Model for AHR activation by kynurenine via oxidized-LDL, TLR2/4, TGFβ, and IDO1

    Energy Technology Data Exchange (ETDEWEB)

    Moyer, Benjamin J. [Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth, Dartmouth Hitchcock Medical Center, One Medical Center Drive, Lebanon, NH 03756 (United States); Rojas, Itzel Y. [Department of Medicine, Geisel School of Medicine at Dartmouth, Dartmouth Hitchcock Medical Center, One Medical Center Drive, Lebanon, NH 03756 (United States); Department of Pharmacology & Toxicology, Geisel School of Medicine at Dartmouth, Dartmouth Hitchcock Medical Center, One Medical Center Drive, Lebanon, NH 03756 (United States); Kerley-Hamilton, Joanna S. [Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth, Dartmouth Hitchcock Medical Center, One Medical Center Drive, Lebanon, NH 03756 (United States); Hazlett, Haley F. [Department of Pharmacology & Toxicology, Geisel School of Medicine at Dartmouth, Dartmouth Hitchcock Medical Center, One Medical Center Drive, Lebanon, NH 03756 (United States); Department of Immunology & Microbiology, Geisel School of Medicine at Dartmouth, Dartmouth Hitchcock Medical Center, One Medical Center Drive, Lebanon, NH 03756 (United States); Nemani, Krishnamurthy V. [Department of Radiology, Geisel School of Medicine at Dartmouth, Dartmouth Hitchcock Medical Center, One Medical Center Drive, Lebanon, NH 03756 (United States); Trask, Heidi W.; West, Rachel J. [Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth, Dartmouth Hitchcock Medical Center, One Medical Center Drive, Lebanon, NH 03756 (United States); Lupien, Leslie E. [Department of Medicine, Geisel School of Medicine at Dartmouth, Dartmouth Hitchcock Medical Center, One Medical Center Drive, Lebanon, NH 03756 (United States); Collins, Alan J. [Department of Immunology & Microbiology, Geisel School of Medicine at Dartmouth, Dartmouth Hitchcock Medical Center, One Medical Center Drive, Lebanon, NH 03756 (United States); and others

    2016-06-01

    Obesity is an increasingly urgent global problem, yet, little is known about its causes and less is known how obesity can be effectively treated. We showed previously that the aryl hydrocarbon receptor (AHR) plays a role in the regulation of body mass in mice fed Western diet. The AHR is a ligand-activated nuclear receptor that regulates genes involved in a number of biological pathways, including xenobiotic metabolism and T cell polarization. This study was an investigation into whether inhibition of the AHR prevents Western diet-based obesity. Male C57Bl/6J mice were fed control and Western diets with and without the AHR antagonist α-naphthoflavone or CH-223191, and a mouse hepatocyte cell line was used to delineate relevant cellular pathways. Studies are presented showing that the AHR antagonists α-naphthoflavone and CH-223191 significantly reduce obesity and adiposity and ameliorates liver steatosis in male C57Bl/6J mice fed a Western diet. Mice deficient in the tryptophan metabolizing enzyme indoleamine 2,3-dioxygenase 1 (IDO1) were also resistant to obesity. Using an AHR-directed, luciferase-expressing mouse hepatocyte cell line, we show that the transforming growth factor β1 (TGFβ1) signaling pathway via PI3K and NF-κB and the toll-like receptor 2/4 (TLR2/4) signaling pathway stimulated by oxidized low-density lipoproteins via NF-κB, each induce luciferase expression; however, TLR2/4 signaling was significantly reduced by inhibition of IDO1. At physiological levels, kynurenine but not kynurenic acid (both tryptophan metabolites and known AHR agonists) activated AHR-directed luciferase expression. We propose a hepatocyte-based model, in which kynurenine production is increased by enhanced IDO1 activity stimulated by TGFβ1 and TLR2/4 signaling, via PI3K and NF-κB, to perpetuate a cycle of AHR activation to cause obesity; and inhibition of the AHR, in turn, blocks the cycle's output to prevent obesity. The AHR with its broad ligand binding

  15. Inhibition of the aryl hydrocarbon receptor prevents Western diet-induced obesity. Model for AHR activation by kynurenine via oxidized-LDL, TLR2/4, TGFβ, and IDO1

    International Nuclear Information System (INIS)

    Moyer, Benjamin J.; Rojas, Itzel Y.; Kerley-Hamilton, Joanna S.; Hazlett, Haley F.; Nemani, Krishnamurthy V.; Trask, Heidi W.; West, Rachel J.; Lupien, Leslie E.; Collins, Alan J.

    2016-01-01

    Obesity is an increasingly urgent global problem, yet, little is known about its causes and less is known how obesity can be effectively treated. We showed previously that the aryl hydrocarbon receptor (AHR) plays a role in the regulation of body mass in mice fed Western diet. The AHR is a ligand-activated nuclear receptor that regulates genes involved in a number of biological pathways, including xenobiotic metabolism and T cell polarization. This study was an investigation into whether inhibition of the AHR prevents Western diet-based obesity. Male C57Bl/6J mice were fed control and Western diets with and without the AHR antagonist α-naphthoflavone or CH-223191, and a mouse hepatocyte cell line was used to delineate relevant cellular pathways. Studies are presented showing that the AHR antagonists α-naphthoflavone and CH-223191 significantly reduce obesity and adiposity and ameliorates liver steatosis in male C57Bl/6J mice fed a Western diet. Mice deficient in the tryptophan metabolizing enzyme indoleamine 2,3-dioxygenase 1 (IDO1) were also resistant to obesity. Using an AHR-directed, luciferase-expressing mouse hepatocyte cell line, we show that the transforming growth factor β1 (TGFβ1) signaling pathway via PI3K and NF-κB and the toll-like receptor 2/4 (TLR2/4) signaling pathway stimulated by oxidized low-density lipoproteins via NF-κB, each induce luciferase expression; however, TLR2/4 signaling was significantly reduced by inhibition of IDO1. At physiological levels, kynurenine but not kynurenic acid (both tryptophan metabolites and known AHR agonists) activated AHR-directed luciferase expression. We propose a hepatocyte-based model, in which kynurenine production is increased by enhanced IDO1 activity stimulated by TGFβ1 and TLR2/4 signaling, via PI3K and NF-κB, to perpetuate a cycle of AHR activation to cause obesity; and inhibition of the AHR, in turn, blocks the cycle's output to prevent obesity. The AHR with its broad ligand binding

  16. Worldwide overview of hydrocarbons and perspectives

    International Nuclear Information System (INIS)

    Tonnac, Alain de; Perves, Jean-Pierre

    2013-12-01

    This publication presents and comments data regarding the share of hydrocarbons in the world energy consumption, hydrocarbon trade flows, the new situation created by the emergence of shale hydrocarbons and the consequences for the world economy, and possible risks. The authors first comment the evolution of energy consumption and outline that the objectives of CO 2 and greenhouse gas emission will not be reached (these emissions increased in 2012 and in 2013). They indicate the emission situation in the USA and Japan, and notice that the objectives defined by the IEA are quite different from those defined by the EU. They analyse the evolutions by distinguishing different periods: 2005-2008 as a reference period, 2008-2012 as a period of change, and the current period as a period of flow inversion. Then, the authors propose two different scenarios of evolution of economic and energy policies. The evolution of hydrocarbon demand is commented, and the levels of reserves (oil, conventional gas, coal, nuclear fuels) are discussed. The market evolution is also discussed, not only from an economic point of view, but also in relationship with geopolitics. The authors notably outline that the energy price is different from one country to the other, discuss the issue of hydrocarbon refining, the role of CO 2 tax

  17. Bioremediation of petroleum hydrocarbons in soil environments

    International Nuclear Information System (INIS)

    Rowell, M.J.; Ashworth, J.; Qureshi, A.A.

    1992-12-01

    The bioremediation of petroleum hydrocarbons in soil environments was reviewed via a literature survey and discussions with workers in relevant disciplines. The impacts of hydrocarbons on soil are discussed along with a range of methods available to assist in their decomposition by soil microorganisms. The range of petroleum-based materials considered includes conventional and synthetic crude oils, refined oils, sludges, asphalts and bitumens, drilling mud residues, creosote tars, and some pesticides. The degradability of hydrocarbons largely depends upon their aqueous solubility and their adsorption on soil surfaces and, therefore, is related to their molecular structures. The ease of decomposition decreases with increasing complexity of structure, in the order aliphatics > aromatics > heterocyclics and asphaltenes (most recalcitrant). Most soils contain an adequate population of microorganisms and hence bioaugmentation may only be needed in special circumstances. Decomposition is fastest in soils where the hydrocarbon loading rate, aeration, nutrition, moisture, and pH are all optimized. At spill sites there is little control over the application rate, although containment measures can assist in either limiting contamination or distributing it more evenly. The enhancement of bioremediation is discussed in light of all these factors. Other techniques such as enhanced aeration, hydrocarbon decomposition by anaerobic processes, surfactants, and burning are also discussed. 211 refs., 11 figs., 10 tabs

  18. Bioremediation of petroleum hydrocarbons in soil environments

    Energy Technology Data Exchange (ETDEWEB)

    Rowell, M J; Ashworth, J; Qureshi, A A

    1992-12-01

    The bioremediation of petroleum hydrocarbons in soil environments was reviewed via a literature survey and discussions with workers in relevant disciplines. The impacts of hydrocarbons on soil are discussed along with a range of methods available to assist in their decomposition by soil microorganisms. The range of petroleum-based materials considered includes conventional and synthetic crude oils, refined oils, sludges, asphalts and bitumens, drilling mud residues, creosote tars, and some pesticides. The degradability of hydrocarbons largely depends upon their aqueous solubility and their adsorption on soil surfaces and, therefore, is related to their molecular structures. The ease of decomposition decreases with increasing complexity of structure, in the order aliphatics > aromatics > heterocyclics and asphaltenes (most recalcitrant). Most soils contain an adequate population of microorganisms and hence bioaugmentation may only be needed in special circumstances. Decomposition is fastest in soils where the hydrocarbon loading rate, aeration, nutrition, moisture, and pH are all optimized. At spill sites there is little control over the application rate, although containment measures can assist in either limiting contamination or distributing it more evenly. The enhancement of bioremediation is discussed in light of all these factors. Other techniques such as enhanced aeration, hydrocarbon decomposition by anaerobic processes, surfactants, and burning are also discussed. 211 refs., 11 figs., 10 tabs.

  19. Emissions of hydrocarbons from combustion of biofuels

    International Nuclear Information System (INIS)

    Olsson, Mona; Persson, Eva Marie.

    1991-10-01

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

  20. Geophysical Responses of Hydrocarbon-impacted Zones at the Various Contamination Conditions

    Science.gov (United States)

    Kim, C.; Ko, K.; Son, J.; Kim, J.

    2008-12-01

    One controlled experiment and two field surveys were conducted to investigate the geoelectrical responses of hydrocarbon-contaminated zones, so called smeared zone, on the geophysical data at the hydrocarbon- contaminated sites with various conditions. One controlled physical model experiment with GPR using fresh gasoline and two different 3-D electrical resistivity investigations at the aged sites. One field site (former military facilities for arms maintenance) was mainly contaminated with lubricating oils and the other (former gas station) was contaminated with gasoline and diesel, respectively. The results from the physical model experiment show that GPR signals were enhanced when LNAPL was present as a residual saturation in the water-saturated system due to less attenuation of the electromagnetic energy through the soil medium of the hydrocarbon-impacted zone (no biodegradation), compared to when the medium was saturated with only water (no hydrocarbon impaction). In the former gas station site, 3-D resistivity results demonstrate that the highly contaminated zones were imaged with low resistivity anomalies since the biodegradation of petroleum hydrocarbons has been undergone for many years, causing the drastic increase in the TDS at the hydrocarbon-impacted zones. Finally, 3-D resistivity data obtained from the former military maintenance site show that the hydrocarbon-contaminated zones show high resistivity anomalies since the hydrocarbons such as lubricating oils at the contaminated soils were not greatly influenced by microbial degradation and has relatively well kept their original physical properties of high electrical resistivity. The results of the study illustrated that the hydrocarbon-impacted zones under various contamination conditions yielded various geophysical responses which include (1) enhanced GPR amplitudes at the fresh LNAPL (Gasoline to middle distillates) spill sites, (2) low electrical resistivity anomalies due to biodegradation at the

  1. Prediction of ecotoxicity of hydrocarbon-contaminated soils using physicochemical parameters

    Energy Technology Data Exchange (ETDEWEB)

    Wong, D.C.L.; Chai, E.Y.; Chu, K.K.; Dorn, P.B.

    1999-11-01

    The physicochemical properties of eight hydrocarbon-contaminated soils were used to predict toxicity to earthworms (Eisenia fetida) and plants. The toxicity of these preremediated soils was assessed using earthworm avoidance, survival, and reproduction and seed germination and root growth in four plant species. No-observed-effect and 25% inhibitory concentrations were determined from the earthworm and plant assays. Physical property measurements and metals analyses of the soils were conducted. Hydrocarbon contamination was characterized by total petroleum hydrocarbons, oil and grease, and GC boiling-point distribution. Univariate and multivariate statistical methods were used to examine relationships between physical and chemical properties and biological endpoints. Soil groupings based on physicochemical properties and toxicity from cluster and principal component analyses were generally similar. Correlation analysis identified a number of significant relationships between soil parameters and toxicity that were used in univariate model development. Total petroleum hydrocarbons by gas chromatography and polars were identified as predictors of earthworm avoidance and survival and seed germination, explaining 65 to 75% of the variation in the data. Asphaltenes also explained 83% of the variation in seed germination. Gravimetric total petroleum hydrocarbons explained 40% of the variation in earthworm reproduction, whereas 43% of the variation in plant root growth was explained by asphaltenes. Multivariate one-component partial least squares models, which identified predictors similar to those identified by the univariate models, were also developed for worm avoidance and survival and seed germination and had predictive powers of 42 and 29%, respectively.

  2. Economic analysis of hydrocarbon exploration by simulation with geological uncertainties (exploratory wells)

    International Nuclear Information System (INIS)

    Chungcharoen, E.

    1997-01-01

    A model was developed to help determine the future development of hydrocarbon reserves. The uncertainties of geological parameters were incorporated into the model in an effort to provide an assessment of the distribution of total hydrocarbon discoveries that are expected to be recovered as a result of exploration activity. The economic parameters were also incorporated into the model in an effort to determine the economic worth of multiple-wells exploration activity. The first part of this study included the geological parameters in the initial field size distribution and the number of fields distribution. Dry hole data was also considered to reflect the exploration risk. The distribution of total hydrocarbon discoveries for a selected number of exploratory wells was determined. The second part of the study included the economic parameters such as the price of oil and gas and the cost of exploration, development and production. The distribution of the number of discoveries and the distribution of total hydrocarbon discoveries was compared to produce a probability distribution of the net present value of a proposed exploration program. The offshore Nova Scotia Shelf basin was chosen for testing the methodology. Several scenarios involving changes in economic parameters were shown. This methodology could help in determining future development programs for hydrocarbon reserves. The methodology can also help governments in policy making decisions regarding taxes and royalty regimes for exploration programs

  3. Mate attraction, retention and expulsion.

    Science.gov (United States)

    Miner, Emily J; Shackelford, Todd K

    2010-02-01

    Sexual selection theory and parental investment theory have guided much of the evolutionary psychological research on human mating. Based on these theories, researchers have predicted and found sex differences in mating preferences and behaviors. Men generally prefer that their long-term partners are youthful and physically attractive. Women generally prefer that their long-term partners have existing resources or clear potential for securing resources and display a willingness to invest those resources in children the relationship might produce. Both men and women, however, desire long-term partners who are kind and intelligent. Once a partner is obtained, men and women act in sex-specific ways to ensure the continuation and exclusivity of the relationship. Men, in particular, engage in behaviors designed to prevent, correct, and anticipate their partner's sexual infidelity. Relationships dissolve for evolutionarily-relevant reasons: infidelity, childlessness, and infertility. The discussion addresses directions for future research.

  4. Condensation Mechanism of Hydrocarbon Field Formation.

    Science.gov (United States)

    Batalin, Oleg; Vafina, Nailya

    2017-08-31

    Petroleum geology explains how hydrocarbon fluids are generated, but there is a lack of understanding regarding how oil is expelled from source rocks and migrates to a reservoir. To clarify the process, the multi-layer Urengoy field in Western Siberia was investigated. Based on this example, we have identified an alternative mechanism of hydrocarbon field formation, in which oil and gas accumulations result from the phase separation of an upward hydrocarbon flow. There is evidence that the flow is generated by the gases released by secondary kerogen destruction. This study demonstrates that oil components are carried by the gas flow and that when the flow reaches a low-pressure zone, it condenses into a liquid with real oil properties. The transportation of oil components in the gas flow provides a natural explanation for the unresolved issues of petroleum geology concerning the migration process. The condensation mechanism can be considered as the main process of oil field formation.

  5. EVALUATION OF PETROLEUM HYDROCARBONS ELUTION FROM SOIL

    Directory of Open Access Journals (Sweden)

    Janina Piekutin

    2015-06-01

    Full Text Available The paper presents studies on oil removal from soil by means of water elution with a help of shaking out the contaminants from the soil. The tests were performed on simulated soil samples contaminated with a mixture of petroleum hydrocarbons. The study consisted in recording the time influence and the number of elution cycles to remove contaminants from the soil. The samples were then subject to the determination of petroleum hydrocarbons, aliphatic hydrocarbons, and BTEX compounds (benzene, toluene, ethylbenzene, xylene. Due to adding various concentrations of petroleum into particular soil samples and applying different shaking times, it was possible to find out the impact of petroleum content and sample shaking duration on the course and possibility of petroleum substances removal by means of elution process.

  6. Direct electroreduction of CO2 into hydrocarbon

    International Nuclear Information System (INIS)

    Winea, Gauthier; Ledoux, Marc-Jacques; Pham-Huu, Cuong; Gangeri, Miriam; Perathoner, Siglinda; Centi, Gabriele

    2006-01-01

    A lot of methods exist to directly reduce carbon dioxide into hydrocarbons: the photoelectrochemical process is certainly the most interesting, essentially due to the similarities with photosynthesis. As the human activities produce a great quantity of CO 2 , this one can then be considered as an infinite source of carbon. The products of this reaction are identical to those obtained during a Fischer-Tropsch reaction, that is to say hydrocarbons, alcohols and carboxylic acids. These works deal with the electrochemical reduction of CO 2 in standard conditions of temperature and pressure. The photochemical part has been replaced by a current generator as electrons source and a KHCO 3 aqueous solution as protons source. The first catalytic results clearly show that it is possible to reduce CO 2 into light hydrocarbons, typically from C1 to C9. (O.M.)

  7. Microbial hydrocarbon degradation - bioremediation of oil spills

    Energy Technology Data Exchange (ETDEWEB)

    Atlas, R M [Louisville Univ., KY (United States). Dept. of Biology

    1991-01-01

    Bioremediation has become a major method employed in restoration of oil-polluted environments that makes use of natural microbial biodegradative activities. Bioremediation of petroleum pollutants overcomes the factors limiting rates of microbial hydrocarbon biodegradation. Often this involves using the enzymatic capabilities of the indigenous hydrocarbon-degrading microbial populations and modifying environmental factors, particularly concentrations of molecular oxygen, fixed forms of nitrogen and phosphate to achieve enhanced rates of hydrocarbon biodegradation. Biodegradation of oily sludges and bioremediation of oil-contaminated sites has been achieved by oxygen addition-e.g. by tilling soils in landfarming and by adding hydrogen peroxide or pumping oxygen into oiled aquifers along with addition of nitrogen- and phosphorous-containing fertilizers. The success of seeding oil spills with microbial preparations is ambiguous. Successful bioremediation of a major marine oil spill has been achieved based upon addition of nitrogen and phosphorus fertilizers. (author).

  8. Scaling Relationships for Adsorption Energies of C2 Hydrocarbons on Transition Metal Surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Jones, G

    2011-08-18

    Using density functional theory calculations we show that the adsorption energies for C{sub 2}H{sub x}-type adsorbates on transition metal surfaces scale with each other according to a simple bond order conservation model. This observation generalizes some recently recognized adsorption energy scaling laws for AH{sub x}-type adsorbates to unsaturated hydrocarbons and establishes a coherent simplified description of saturated as well as unsaturated hydrocarbons adsorbed on transition metal surfaces. A number of potential applications are discussed. We apply the model to the dehydrogenation of ethane over pure transition metal catalysts. Comparison with the corresponding full density functional theory calculations shows excellent agreement.

  9. Bioremediation of Petroleum Hydrocarbon Contaminated Sites

    Energy Technology Data Exchange (ETDEWEB)

    Fallgren, Paul

    2009-03-30

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

  10. The reorganization of the Russian hydrocarbons industry: an overview

    International Nuclear Information System (INIS)

    Locatelli, C.

    1995-01-01

    The purpose of this article is to present the main guidelines for the reorganization of the Russian hydrocarbon industry. Specifically, it focuses on the economic conditions concerning the constitution of Russian oil companies in an uncertain environment. In Russia, one of the main problems is to create autonomous energy enterprises. The main conclusion is that up to now the reorganization has been essentially juridical, connected with the constitution of joint stock companies. From an economic point of view, the organizational model behind these joint stock companies is not very well defined and lacks clearly defined coordination mechanisms. (author)

  11. Extraction Techniques for Polycyclic Aromatic Hydrocarbons in Soils

    Science.gov (United States)

    Lau, E. V.; Gan, S.; Ng, H. K.

    2010-01-01

    This paper aims to provide a review of the analytical extraction techniques for polycyclic aromatic hydrocarbons (PAHs) in soils. The extraction technologies described here include Soxhlet extraction, ultrasonic and mechanical agitation, accelerated solvent extraction, supercritical and subcritical fluid extraction, microwave-assisted extraction, solid phase extraction and microextraction, thermal desorption and flash pyrolysis, as well as fluidised-bed extraction. The influencing factors in the extraction of PAHs from soil such as temperature, type of solvent, soil moisture, and other soil characteristics are also discussed. The paper concludes with a review of the models used to describe the kinetics of PAH desorption from soils during solvent extraction. PMID:20396670

  12. Predicting the distribution of contamination from a chlorinated hydrocarbon release

    Energy Technology Data Exchange (ETDEWEB)

    Lupo, M.J. [K.W. Brown Environmental Services, College Station, TX (United States); Moridis, G.J. [Lawrence Berkeley Laboratory, Berkeley, CA (United States)

    1995-03-01

    The T2VOC model with the T2CG1 conjugate gradient package was used to simulate the motion of a dense chlorinated hydrocarbon plume released from an industrial plant. The release involved thousands of kilograms of trichloroethylene (TCE) and other chemicals that were disposed of onsite over a period of nearly twenty years. After the disposal practice ceased, an elongated plume was discovered. Because much of the plume underlies a developed area, it was of interest to study the migration history of the plume to determine the distribution of the contamination.

  13. Extraction Techniques for Polycyclic Aromatic Hydrocarbons in Soils

    Directory of Open Access Journals (Sweden)

    E. V. Lau

    2010-01-01

    Full Text Available This paper aims to provide a review of the analytical extraction techniques for polycyclic aromatic hydrocarbons (PAHs in soils. The extraction technologies described here include Soxhlet extraction, ultrasonic and mechanical agitation, accelerated solvent extraction, supercritical and subcritical fluid extraction, microwave-assisted extraction, solid phase extraction and microextraction, thermal desorption and flash pyrolysis, as well as fluidised-bed extraction. The influencing factors in the extraction of PAHs from soil such as temperature, type of solvent, soil moisture, and other soil characteristics are also discussed. The paper concludes with a review of the models used to describe the kinetics of PAH desorption from soils during solvent extraction.

  14. Hydrocarbon Plume Dynamics in the Worldś Most Spectacular Hydrocarbon Seeps, Santa Barbara Channel, California

    Science.gov (United States)

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

    2006-12-01

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

  15. Electrochemical removal of NOx and hydrocarbons

    DEFF Research Database (Denmark)

    Friedberg, Anja Zarah

    on the electrodes during polarisation, probably because of strong adsorption of the hydrocarbon relative to NO. On LSF/CGO electrode the impregnation of ionic conducting material increased the oxidation of NO to NO2 which is an important step before nitrogen formation. The propene inhibited this reaction because....... This could only be done if the electrode was impregnated with BaO. The nitrate formation did not seem to be inhibited by the presence of the hydrocarbon. However, the oxidation of propene was inhibited by the BaO because the active sites for oxidations were partially covered by the BaO nanoparticles...

  16. Mathematics of Periodic Tables for Benzenoid Hydrocarbons.

    Science.gov (United States)

    Dias, Jerry Ray

    2007-01-01

    The upper and lower bounds for invariants of polyhex systems based on the Harary and Harborth inequalities are studied. It is shown that these invariants are uniquely correlated by the Periodic Table for Benzenoid Hydrocarbons. A modified periodic table for total resonant sextet (TRS) benzenoids based on the invariants of Ds and r(empty) is presented; Ds is the number of disconnections among the empty rings for fused TRS benzenoid hydrocarbons. This work represents a contribution toward deciphering the topological information content of benzenoid formulas.

  17. Plasma-catalytic reforming of liquid hydrocarbons

    International Nuclear Information System (INIS)

    Nedybaliuk, O.A.; Chernyak, V.Ya; Kolgan, V.V.; Iukhymenko, V.V.; Solomenko, O.V.; Fedirchyk, I.I.; Martysh, E.V.; Demchina, V.P.; Klochok, N.V.; Dragnev, S.V.

    2015-01-01

    The series of experiments studying the plasma-catalytic reforming of liquid hydrocarbons was carried out. The dynamic plasma-liquid system based on a low-power rotating gliding arc with solid electrodes was used for the investigation of liquid hydrocarbons reforming process. Conversion was done via partial oxidation. A part of oxidant flow was activated by the discharge. Synthesis-gas composition was analysed by means of mass-spectrometry and gas-chromatography. A standard boiler, which operates on natural gas and LPG, was used for the burning of synthesis-gas

  18. Motor fuels by hydrogenation of liquid hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    1938-05-07

    A process is disclosed for the production of knock-stable low-boiling motor fuels by conversion of liquid hydrocarbons which are vaporizable under the reaction conditions, which comprises passing the initial material at a temperature above 380/sup 0/C in a true vapor phase under pressure of more than 40 atmospheres together with hydrogen and gaseous hydrocarbons containing more than 1 carbon atom in the molecule in an amount by volume larger than that of the hydrogen over catalysts stable to poisoning stationarily confined in the reaction vessel.

  19. Calculation of Binary Adsorption Equilibria: Hydrocarbons and Carbon Dioxide on Activated Carbon

    DEFF Research Database (Denmark)

    Marcussen, Lis; Krøll, A.

    1999-01-01

    Binary adsorption equilibria are calculated by means of a mathematical model for multicomponent mixtures combined with the SPD (Spreading Pressure Dependent) model for calculation of activity coefficients in the adsorbed phase. The model has been applied successfully for the adsorption of binary ...... mixtures of hydrocarbons and carbon dioxide on activated carbons. The model parameters have been determined, and the model has proven to be suited for prediction of adsorption equilibria in the investigated systems....

  20. Stability of hydrocarbon systems at thermobaric conditions corresponding to depth down to 50 km

    Science.gov (United States)

    Kutcherov, V.; Kolesnikov, A.; Mukhina, E.; Serovaiskii, A.

    2017-12-01

    Most of the theoretical models show that crude oil stability is limited by the depth of 6-8 km (`oil window'). Commercial discovery of crude oil deposits on the depth more than 10 km in the different petroleum basins worldwide casts doubt on the validity of the above-mentioned theoretical calculations. Therefore, the question at which depth complex hydrocarbon systems could be stable is important not only from fundamental research point of view but has a great practical application. To answer this question a hydrocarbon mixture was investigated under thermobaric conditions corresponding to the conditions of the Earth's lower crust. Experiments were conducted by means of Raman Mössbauer spectroscopy. The results obtained show that the complex hydrocarbon systems could be stable and remain their qualitative and quantitative composition at temperature 320-450 °C and pressure 0.7-1.4 GPa. The oxidizing resistance of hydrocarbon system was tested in the modelled the Earth's crust surrounding. The hydrocarbon system stability at the presence of Fe2O3 strongly confirms that the Earth's crust oxygen fugacity does not influence on petroleum composition. The data obtained broaden our knowledge about the possible range of depths for crude oil and natural gas deposits in the Earth's crust and give us the possibility to revise the depth of petroleum deposits occurrence.