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)

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

Diagnostic performance of sonoelastographic Tsukuba score and strain ratio in evaluation of breast masses

Directory of Open Access Journals (Sweden)

Mahmoud Abd Elaziz Dawood

2018-03-01

Full Text Available The aim of this prospective study was to evaluate the diagnostic performance of the use of strain index ratio by sonoelastography to differentiate between benign and malignant breast lesions. Patients & Methods: This prospective study including 40 females, complaining of breast masses which were suspicious to be malignant on clinical examination. All patients were submitted to B-mode Ultrasound and sonoelastography. Biopsy as a gold standard and pathological study were done for all breast lesions. Results: US examination of every mass was done and categorized according to BI-RADS categories according to ACR2013, according to US lexicon. Sonoelastography examination with Lesions classification was performed on the basis of a 5-point scoring method proposed by Tsukuba elasticity score. Then measurements of strain ratio were done. Statistical analysis of combination of the three methods was sensitivity of 96.7%, specificity of 100% when we use cut off value of 3–4 in elastography score and ≤3 cut off value of strain ratio. Conclusion: The combined use of strain ratio with Tsukuba score and BI-RADS categorization increased the diagnostic performance in differentiation between benign and malignant breast lesions. Keywords: Elastography, Breast masses, Strain ratio, Ultrasound, BI-RADS classification, Tsukuba score

Variations in the stable isotope ratios of specific aromatic and aliphatic hydrocarbons from coal conversion processes

Energy Technology Data Exchange (ETDEWEB)

McRae, C.; Snape, C.E.; Fallick, A.E. [University of Strathclyde, Glasgow (United Kingdom). Dept. of Pure and Applied Chemistry

1998-07-01

To establish the scope for applying gas chromatography-isotope ratio mass spectrometry ({sup {delta}-13}C GC-IRMS) to molecular recognition problems in coal utilisation, {sup 13}C/{sup 12}C isotope ratios were determined for n-alkanes and polycyclic aromatic hydrocarbons (PAHs) as a function of coal rank and process conditions. Six coals ranging from a lignite to a low volatile bituminous coal were subjected to chloroform extraction, fixed-bed pyrolysis under hydrogen pressure (hydropyrolysis) and fluidised-bed (flash) pyrolysis. No significant variations in the stable isotope ratios of n-alkanes were evident as a function of either rank or conversion regime. In contrast, the isotope ratios of PAHs show large variations with those for hydropyrolysis (-23 to -25 parts per thousand) being similar to the bulk values of the initial coals and being isotopically heavier (less negative) than their fluidised-bed pyrolysis counterparts by 2-3 parts per thousand. However, the PAHs from fluidised-bed pyrolysis, which resemble closely those obtained from high temperature coal carbonization, are still heavier (by 2-3 parts per thousand) than those from diesel particulates and coal gasification and combustion residues. This provides a firm basis for the source apportionment of airborne PAHs in the proximity of coking plants, particularly with no major variations in the PAH isotope ratios being found as a function of rank.

Sources and distribution of aromatic hydrocarbons in a tropical marine protected area estuary under influence of sugarcane cultivation.

Science.gov (United States)

Arruda-Santos, Roxanny Helen de; Schettini, Carlos Augusto França; Yogui, Gilvan Takeshi; Maciel, Daniele Claudino; Zanardi-Lamardo, Eliete

2018-05-15

Goiana estuary is a well preserved marine protected area (MPA) located on the northeastern coast of Brazil. Despite its current state, human activities in the watershed represent a potential threat to long term local preservation. Dissolved/dispersed aromatic hydrocarbons and polycyclic aromatic hydrocarbons (PAHs) were investigated in water and sediments across the estuarine salt gradient. Concentration of aromatic hydrocarbons was low in all samples. According to results, aromatic hydrocarbons are associated to suspended particulate matter (SPM) carried to the estuary by river waters. An estuarine turbidity maximum (ETM) was identified in the upper estuary, indicating that both sediments and contaminants are trapped prior to an occasional export to the adjacent sea. PAHs distribution in sediments were associated with organic matter and mud content. Diagnostic ratios indicated pyrolytic processes as the main local source of PAHs that are probably associated with sugarcane burning and combustion engines. Low PAH concentrations probably do not cause adverse biological effects to the local biota although their presence indicate anthropogenic contamination and pressure on the Goiana estuary MPA. Copyright © 2017 Elsevier B.V. All rights reserved.

Monitoring in situ biodegradation of hydrocarbons by using stable carbon isotopes

International Nuclear Information System (INIS)

Aggarwal, P.K.; Hinchee, R.E.

1991-01-01

Spilled or leaked nonhalogenated petroleum hydrocarbons in the soil can generally be metabolized by indigenous, aerobic bacteria. In situ biological degradation of hydrocarbons may be accelerated by supplying inorganic nutrients and/or oxygen. Approaches to monitoring and verifying enhanced in situ biodegradation have included measurements of changes over time in the (a) concentration of hydrocarbons, (b) temperature, (c) number of hydrocarbon-degrading microorganisms, (d) ratio of fast-degrading hydrocarbons (e.g., pristanes or phytanes), and (e) metabolic intermediates. Measurements of oxygen consumption over time and elevated carbon dioxide concentrations in soil gas also have been used as indicators of hydrocarbon degradation. An alternative approach that may help substantiate biodegradation is to measure stable carbon isotope ratios in soil gas CO 2 . Stable carbon isotope ratio analysis is inexpensive and commercially available at many laboratories. Carbon dioxide produced by hydrocarbon degradation may be distinguished from that produced by other processes based on the carbon isotopic compositions characteristic of the source material and/or fractionation accompanying microbial metabolism. Here the authors demonstrate the applicability of the stable isotope technique for monitoring enhanced. aerobic biodegradation of hydrocarbons using data from three locations in the United States

Source identification and seasonal variation of polycyclic aromatic hydrocarbons associated with atmospheric fine and coarse particles in the Metropolitan Area of Porto Alegre, RS, Brazil

Science.gov (United States)

Teixeira, Elba Calesso; Agudelo-Castañeda, Dayana M.; Fachel, Jandyra Maria Guimarães; Leal, Karen Alam; Garcia, Karine de Oliveira; Wiegand, Flavio

2012-11-01

The purpose of the present study was to evaluate the polycyclic aromatic hydrocarbons (PAHs) in fine (PM2.5) and coarse particles (PM2.5-10) in an urban and industrial area in the Metropolitan Area of Porto Alegre (MAPA), Brazil. Sixteen U.S. Environmental Protection Agency (EPA) priority polycyclic aromatic hydrocarbons (PAHs) were measured. Filters containing ambient air particulate were extracted with dichloromethane using Soxhlet. Extracts were later analyzed, for determining PAH concentrations, using a gaseous chromatograph coupled with a mass spectrometer (GC-MS). The polycyclic aromatic hydrocarbons (PAHs) were more concentrated in PM2.5 with an average of 70% of total PAHs in the MAPA. The target PAH apportionment among the main emission sources was carried out by diagnostic PAH concentration ratios, and principal component analysis (PCA). PAHs with higher molecular weight showed higher percentages in the fine particles in the MAPA. Based on the diagnostic ratios and PCA analysis, it may be concluded that the major contribution of PAHs was from vehicular sources (diesel and gasoline), especially in the PM2.5 fraction, as well as coal and wood burning. The winter/summer ratio in the PM2.5 and PM2.5-10 fractions in the MAPA was 3.1 and 1.8, respectively, revealing the seasonal variation of PAHs in the two fractions. The estimated toxicity equivalent factor (TEF), used to assess the contribution of the carcinogenic potency, confirms a significant presence of the moderately active carcinogenic PAHs BaP and DahA in the samples collected in the MAPA.

Comparison of atmosphere/aquatic environment concentration ratio of volatile chlorinated hydrocarbons between temperate regions and Antarctica.

Science.gov (United States)

Zoccolillo, Lelio; Amendola, Luca; Insogna, Susanna

2009-09-01

For the purpose of understanding the transport and deposition mechanisms and the air-water distribution of some volatile chlorinated hydrocarbons (VCHCs), their atmosphere/aquatic environment concentration ratio was evaluated. In addition, for the purpose of differentiating VCHC behaviour in a temperate climate from its behaviour in a polar climate, the atmosphere/aquatic environment concentration ratio evaluated in matrices from temperate zones was compared with the concentration ratio evaluated in Antarctic matrices. In order to perform air samplings also at rigid Antarctic temperatures, the sampling apparatus, consisting of a diaphragm pump and canisters, was suitably modified. Chloroform, 1,1,1-trichloroethane, tetrachloromethane, 1,1,2-trichloroethylene and tetrachloroethylene were measured in air, water and snow using specific techniques composed of a purpose-made cryofocusing-trap-injector (for air samples) and a modified purge-and-trap injector (for aqueous samples) coupled to a gas chromatograph with mass spectrometric detection operating in selected ion monitoring mode. The VCHCs were retrieved in all the investigated matrices, both Italian and Antarctic, with concentrations varying from tens to thousands of ng m(-3) in air and from digits to hundreds of ng kg(-1) in water and snow. The atmosphere/aquatic environment concentration ratios were always found to be lower than 1. In particular, the Italian air/water concentration ratios were smaller than the Antarctic ones, by reason of the higher atmospheric photochemical activity in temperate zones. On the other hand, the Antarctic air/snow concentration ratios proved to be largely in favour of snow with respect to the Italian ratios, thus corroborating the hypothesis of a more efficient VCHC deposition mechanism and accumulation on Antarctic snow.

The Attribute for Hydrocarbon Prediction Based on Attenuation

International Nuclear Information System (INIS)

Hermana, Maman; Harith, Z Z T; Sum, C W; Ghosh, D P

2014-01-01

Hydrocarbon prediction is a crucial issue in the oil and gas industry. Currently, the prediction of pore fluid and lithology are based on amplitude interpretation which has the potential to produce pitfalls in certain conditions of reservoir. Motivated by this fact, this work is directed to find out other attributes that can be used to reduce the pitfalls in the amplitude interpretation. Some seismic attributes were examined and studies showed that the attenuation attribute is a better attribute for hydrocarbon prediction. Theoretically, the attenuation mechanism of wave propagation is associated with the movement of fluid in the pore; hence the existence of hydrocarbon in the pore will be represented by attenuation attribute directly. In this paper we evaluated the feasibility of the quality factor ratio of P-wave and S-wave (Qp/Qs) as hydrocarbon indicator using well data and also we developed a new attribute based on attenuation for hydrocarbon prediction -- Normalized Energy Reduction Stack (NERS). To achieve these goals, this work was divided into 3 main parts; estimating the Qp/Qs on well log data, testing the new attribute in the synthetic data and applying the new attribute on real data in Malay Basin data. The result show that the Qp/Qs is better than Poisson's ratio and Lamda over Mu as hydrocarbon indicator. The curve, trend analysis and contrast of Qp/Qs is more powerful at distinguishing pore fluid than Poisson ratio and Lamda over Mu. The NERS attribute was successful in distinguishing the hydrocarbon from brine on synthetic data. Applying this attribute on real data on Malay basin, the NERS attribute is qualitatively conformable with the structure and location where the gas is predicted. The quantitative interpretation of this attribute for hydrocarbon prediction needs to be investigated further

Identifying risk sources of air contamination by polycyclic aromatic hydrocarbons.

Science.gov (United States)

Huzlik, Jiri; Bozek, Frantisek; Pawelczyk, Adam; Licbinsky, Roman; Naplavova, Magdalena; Pondelicek, Michael

2017-09-01

This article is directed to determining concentrations of polycyclic aromatic hydrocarbons (PAHs), which are sorbed to solid particles in the air. Pollution sources were identified on the basis of the ratio of benzo[ghi]perylene (BghiPe) to benzo[a]pyrene (BaP). Because various important information is lost by determining the simple ratio of concentrations, least squares linear regression (classic ordinary least squares regression), reduced major axis, orthogonal regression, and Kendall-Theil robust diagnostics were utilized for identification. Statistical evaluation using all aforementioned methods demonstrated different ratios of the monitored PAHs in the intervals examined during warmer and colder periods. Analogous outputs were provided by comparing gradients of the emission factors acquired from the measured concentrations of BghiPe and BaP in motor vehicle exhaust gases. Based on these outputs, it was possible plausibly to state that the influence of burning organic fuels in heating stoves is prevalent in colder periods whereas in warmer periods transport was the exclusive source because other sources of PAH emissions were not found in the examined locations. Copyright © 2017 Elsevier Ltd. All rights reserved.

USEFULNESS OF FREE THYROXINE TO FREE TRIIODOTHYRONINE RATIO FOR DIAGNOSTICS OF VARIOUS TYPES OF HYPERTHYROIDISM

Directory of Open Access Journals (Sweden)

Jernej Grmek

2015-06-01

Full Text Available Background: Different types of hyperthyroidism are treated differently. The correct diagnosis enables the adequate treatment. Clinical experiences suggest that free thyroxine (fT4 to free triiodothyronine (fT3 ratio is different for different types of hyperthyroidism. Considering the paucity of literature data on the topic our aim was to evaluate the role of the serum fT4 to fT3 (fT4/fT3ratio in diagnostics of various types of hyperthyroidism.Methods: In retrospective clinical study we included 440 consecutive subjects, examined between February and August 2010, 350 females and 90 males aged between 15 and 97 years, among them 225 healthy subjects (HS, 80 patients with Graves' disease (GD, 48 with toxic adenoma (TA, 61 patients with hyperthyroid Hashimoto’s thyroiditis (HHT, 17 with subacute thyroiditis (ST, and 9 patients with iodine-induced hyperthyroidism (IIH. Thyrotropin (TSH, fT4, fT3 and thyroid autoantibodies were measured. The fT4/fT3 ratio was calculated.Results: The fT4/fT3 ratio was significantly different for various disorders causing hyperthyroidism (p<0.001. Compared with the fT4/fT3 ratio in HS (2.86±0.52, the ratio was significantly higher in HHT and ST (3.27±0.72 and 3.31±0.54, respectively, p<0.001 for both. In GD, the fT4/fT3 ratio was the lowest (2.55±0.58 and in IIH the highest (5.13±1.97. Both ratios significantly differed from the ratio in HS (p<0.001 for both and in other hyperthyroid patients (p<0.001 for both. In patients with TA, the fT4/fT3 ratio was similar as in HS (2.85±0.71 (p=0.085.Conclusion: The fT4/fT3 ratio is different in various types of hyperthyroidism and therefore represents a useful tool in the diagnostic procedure.

Evaluation of compression ratio using JPEG 2000 on diagnostic images in dentistry

International Nuclear Information System (INIS)

Jung, Gi Hun; Han, Won Jeong; Yoo, Dong Soo; Kim, Eun Kyung; Choi, Soon Chul

2005-01-01

To find out the proper compression ratios without degrading image quality and affecting lesion detectability on diagnostic images used in dentistry compressed with JPEG 2000 algorithm. Sixty Digora peri apical images, sixty panoramic computed radiographic (CR) images, sixty computed tomography (CT) images, and sixty magnetic resonance (MR) images were compressed into JPEG 2000 with ratios of 10 levels from 5:1 to 50:1. To evaluate the lesion detectability, the images were graded with 5 levels (1 : definitely absent ; 2 : probably absent ; 3 : equivocal ; 4 : probably present ; 5 : definitely present), and then receiver operating characteristic analysis was performed using the original image as a gold standard. Also to evaluate subjectively the image quality, the images were graded with 5 levels (1 : definitely unacceptable ; 2 : probably unacceptable ; 3 : equivocal ; 4 : probably acceptable ; 5 : definitely acceptable), and then paired t-test was performed. In Digora, CR panoramic and CT images, compressed images up to ratios of 15:1 showed nearly the same lesion detectability as original images, and in MR images, compressed images did up to ratios of 25:1. In Digora and CR panoramic images, compressed images up to ratios of 5:1 showed little difference between the original and reconstructed images in subjective assessment of image quality. In CT images, compressed images did up to ratios of 10:1 and in MR images up to ratios of 15:1. We considered compression ratios up to 5:1 in Digora and CR panoramic images, up to 10:1 in CT images, up to 15:1 in MR images as clinically applicable compression ratios.

The analysis of hydrocarbons by dual-energy gamma-ray densitometry

International Nuclear Information System (INIS)

Taylor, T.; Reynolds, P.W.; Lipsett, J.J.

1985-11-01

Various hydrocarbons have been analyzed noninvasively by dual-energy gamma-ray densitometry. The hydrogen/carbon atomic ratio was deduced for pure hydrocarbons while for heavy oil process samples, the ash content was inferred

Partitioning and source diagnostics of polycyclic aromatic hydrocarbons in rivers in Tianjin, China

International Nuclear Information System (INIS)

Shi, Z.; Tao, S.; Pan, B.; Liu, W.X.; Shen, W.R.

2007-01-01

Water, suspended particulate matter (SPM), and sediment samples were collected from ten rivers in Tianjin and analyzed for 16 polycyclic aromatic hydrocarbons (PAHs), dissolved organic carbon (DOC), particulate organic carbon (POC) in SPM and total organic carbon (TOC) in sediment. The behavior and fate of PAHs influenced by these parameters were examined. Generally, organic carbon was the primary factor controlling the behavior of the 16 PAH species. Partitioning of PAHs between SPM and water phase was studied, and K OC for some PAH species were found to be significantly higher than the predicted values. The source of PAHs contamination was diagnosed by using PAH isomer ratios. Coal combustion was identified to be a long-term and prevailing contamination source for sediment, while sewage/wastewater source could reasonably explain a short-term PAHs contamination of SPM. - Distribution of PAHs among water, suspended solids and sediment was under strong influence of naturally occurring organic carbon

Time-dependent analysis of visible helium line-ratios for electron temperature and density diagnostic using synthetic simulations on NSTX-U

Energy Technology Data Exchange (ETDEWEB)

Muñoz Burgos, J. M., E-mail: jmunozbu@pppl.gov; Stutman, D.; Tritz, K. [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218 (United States); Barbui, T.; Schmitz, O. [Department of Engineering Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States)

2016-11-15

Helium line-ratios for electron temperature (T{sub e}) and density (n{sub e}) plasma diagnostic in the Scrape-Off-Layer (SOL) and edge regions of tokamaks are widely used. Due to their intensities and proximity of wavelengths, the singlet, 667.8 and 728.1 nm, and triplet, 706.5 nm, visible lines have been typically preferred. Time-dependency of the triplet line (706.5 nm) has been previously analyzed in detail by including transient effects on line-ratios during gas-puff diagnostic applications. In this work, several line-ratio combinations within each of the two spin systems are analyzed with the purpose of eliminating transient effects to extend the application of this powerful diagnostic to high temporal resolution characterization of plasmas. The analysis is done using synthetic emission modeling and diagnostic for low electron density NSTX SOL plasma conditions by several visible lines. Quasi-static equilibrium and time-dependent models are employed to evaluate transient effects of the atomic population levels that may affect the derived electron temperatures and densities as the helium gas-puff penetrates the plasma. The analysis of a wider range of spectral lines will help to extend this powerful diagnostic to experiments where the wavelength range of the measured spectra may be constrained either by limitations of the spectrometer or by other conflicting lines from different ions.

Analysing Diagnostic Assessment on the Ratio of Sine in a Right Triangle

Science.gov (United States)

Andika, R.; Juandi, D.; Rosjanuardi, R.

2017-09-01

This study aims to develop diagnostic assessment with the special topic of the ratio of sinus in a right triangle and analyze the result whether the students are ready to continue to the next lesson of trigonometry specially the sinus rule. The methodology that use in this study is a design research of Plomp model which is it comprises of 3 phases: (a) preliminary research; (b) prototyping phase; and (c) assessment phase. The findings show that almost half of students made a mistake in determining the ratio of sin in a right triangle, consequently the procedure for solving the problem went wrong. In strategic competency and adaptive communication most of students did not solve the problem that was given. According to the result, the students have to get remedial program before to the next lesson, the rule of sin.

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.

Evaluation of synthetic hydrocarbons for mark-recapture studies on the red milkweed beetle.

Science.gov (United States)

Ginzel, Matthew D; Hanks, Lawrence M

2002-05-01

This study evaluates the potential for using blends of synthetic hydrocarbons in mark-recapture studies of insects. To test the durability of hydrocarbons, we applied a blend of five straight-chain hydrocarbons (C24, C21, C26. C28, C30) to detached elytra of the red milkweed beetle, Tetraopes tetrophthalmus (Forster) (Coleoptera: Cerambycidae), mounted the elytra on pins, and placed them in an exposed location outdoors. The amount of hydrocarbons on the elytra did not change over time, even after two months of exposure to sun and rain. Synthetic hydrocarbons applied to the elytra of living beetles did not significantly influence their longevity or mating success in a laboratory study. and the amounts of hydrocarbons did not change with age. The invariability of hydrocarbon ratios over time suggests that blends could provide a nearly infinite variety of ratios to mark individual insects uniquely and indelibly with a hydrocarbon "fingerprint." This technique offers a convenient, safe, and durable means of individually marking insects and may find application in field studies of larger bodied insects that are long-lived and sedentary.

Study of nitro-polycyclic aromatic hydrocarbons in fine and coarse atmospheric particles

Science.gov (United States)

Teixeira, Elba Calesso; Garcia, Karine Oliveira; Meincke, Larissa; Leal, Karen Alam

2011-08-01

The purpose of the present study was to evaluate six nitro-polycyclic aromatic hydrocarbons (NPAHs) in fine (MAPA), RS, Brazil. The method used was of NPAHs isolation and derivatization, and subsequent gas chromatography by electron capture detection (CG/ECD). Results revealed a higher concentration of NPAHs, especially 3-nitrofluoranthene and 1-nitropyrene, in fine particles in the sampling sites studied within the MAPA. The diagnostic ratios calculated for PAHs and NPAHs identified the influence of heavy traffic, mainly of diesel emissions. The correlation of NPAHs with other pollutants (NO x, NO 2, NO and O 3) evidence the influence of vehicular emissions in the MAPA. The seasonal variation evidenced higher NPAHs concentrations in the fine particles during winter for most compounds studied.

Method for upgrading diene-containing hydrocarbon mixtures

Energy Technology Data Exchange (ETDEWEB)

Kidwell, L.E. Jr.; Holcomb, D.E.

1984-05-22

There is disclosed a method for upgrading of hydrocarbon mixtures, so as to reduce their content of gum precursors such as diolefins and pseudo-diolefins, and provide a resulting product mixture suitable for mild hydrogenation, for use as a motor fuel or as a feed stock to an extraction unit. The process comprises obtaining a hydrocarbon mixture containing about 60-90 wt. % of aromatic components, about 3-40 wt. % of dienes and pseudodienes, and monoolefins, and up to about 6 wt. % of relatively unreactive organic compounds, reacting this mixture with elemental sulfur in the approximate weight ratio of about 5-95 wt. % of the hydrocarbon mixture with about 95-5 wt. % of elemental sulfur, the reaction being carried out at a temperature in the range of 100/sup 0/-150/sup 0/ C. for about 10 minutes to 24 hours with good mixing, removing the unreacted materials by distillation and separating a sulfur-hydrocarbon reaction product to provide the upgraded hydrocarbon mixture.

Aliphatic hydrocarbons and triterpane biomarkers in mangrove oyster (Crassostrea belcheri) from the west coast of Peninsular Malaysia.

Science.gov (United States)

Vaezzadeh, Vahab; Zakaria, Mohamad Pauzi; Bong, Chui Wei

2017-11-15

The Straits of Malacca is one of the world's busiest shipping routes where frequent oil spills occur. Rapid development in the west coast of Peninsular Malaysia is the other major source of petroleum pollution in this narrow waterway. In order to identify occurrence and origin of hydrocarbons in the Straits, mangrove oysters (Crassostrea belcheri) were collected from five sampling locations and analysed for n-alkanes and biomarkers. Soxhlet apparatus and two step column chromatography were used for extraction, purification and fractionation of the oysters. Petroleum origin n-alkanes were detected in majority of the sampling locations which is indicative of anthropogenic activities in this region. Using source and maturity diagnostic ratios for hopanes revealed used crankcase oil as the main source of petroleum hydrocarbons in oysters from all sampling locations except for the Pulau Merambong where signature of South East Asia crude oil (SEACO) was detected. Copyright © 2017 Elsevier Ltd. All rights reserved.

POLYCYCLIC AROMATIC HYDROCARBON AND EMISSION LINE RATIOS IN ACTIVE GALACTIC NUCLEI AND STARBURST GALAXIES

International Nuclear Information System (INIS)

Sales, Dinalva A.; Pastoriza, M. G.; Riffel, R.

2010-01-01

We study the polycyclic aromatic hydrocarbon (PAH) bands, ionic emission lines, and mid-infrared continuum properties in a sample of 171 emission line galaxies taken from the literature plus 15 new active galactic nucleus (AGN) Spitzer spectra. We normalize the spectra at λ = 23 μm and grouped them according to the type of nuclear activity. The continuum shape steeply rises for longer wavelengths and can be fitted with a warm blackbody distribution of T ∼ 150-300 K. The brightest PAH spectral bands (6.2, 7.7, 8.6, 11.3, and 12.7 μm) and the forbidden emission lines of [Si II] 34.8 μm, [Ar II] 6.9 μm, [S III] 18.7 and 33.4 μm were detected in all the starbursts and in ∼80% of the Seyfert 2. Taking under consideration only the PAH bands at 7.7 μm, 11.3 μm, and 12.7 μm, we find that they are present in ∼80% of the Seyfert 1, while only half of this type of activity show the 6.2 μm and 8.6 μm PAH bands. The observed intensity ratios for neutral and ionized PAHs (6.2 μm/7.7 μm x 11.3 μm/7.7 μm) were compared to theoretical intensity ratios, showing that AGNs have higher ionization fraction and larger PAH molecules (≥180 carbon atoms) than SB galaxies. The ratio between the ionized (7.7 μm) and the neutral PAH bands (8.6 μm and 11.3 μm) are distributed over different ranges for AGNs and SB galaxies, suggesting that these ratios could depend on the ionization fraction, as well as on the hardness of the radiation field. The ratio between the 7.7 μm and 11.3 μm bands is nearly constant with the increase of [Ne III]15.5 μm/[Ne II] 12.8 μm, indicating that the fraction of ionized to neutral PAH bands does not depend on the hardness of the radiation field. The equivalent width of both PAH features show the same dependence (strongly decreasing) with [Ne III]/[Ne II], suggesting that the PAH molecules, emitting either ionized (7.7 μm) or neutral (11.3 μm) bands, may be destroyed with the increase of the hardness of the radiation field.

Distribution and origins of n-alkanes, hopanes, and steranes in rivers and marine sediments from Southwest Caspian coast, Iran: implications for identifying petroleum hydrocarbon inputs.

Science.gov (United States)

Shirneshan, Golshan; Bakhtiari, Alireza Riyahi; Memariani, Mahmoud

2016-09-01

The occurrence of n-alkanes and biomarkers (hopane and sterane) in surface sediments from Southwestern coasts of Caspian Sea and 28 rivers arriving to this lake, determined with a gas chromatography-mass spectrometry method, was used to assess the impacts of anthropogenic activities in the studied area. The concentrations of total n-alkanes (Σ21 n-alkane) in costal and riverine sediments varied from 249.2 to 3899.5 and 56 to 1622.4 μg g(-1), respectively. An evaluation of the source diagnostic indices indicated that petroleum related sources (petrogenic) were mainly contributed to n-alkanes in costal and most riverine sediments. Only the hydrocarbons in sediment of 3 rivers were found to be mainly of biogenic origin. Principal component analysis using hopane diagnostic ratios in costal and riverine sediments, and Anzali, Turkmenistan, and Azerbaijan oils were used to identify the sources of hydrocarbons in sediments. It was indicated that the anthropogenic contributions in most of the costal sediment samples are dominated with inputs of oil spills from Turkmenistan and Azerbaijan countries.

Exposure to widespread environmental endocrine disrupting chemicals and human sperm sex ratio

International Nuclear Information System (INIS)

Jurewicz, Joanna; Radwan, Michał; Sobala, Wojciech; Radwan, Paweł; Jakubowski, Lucjusz; Wielgomas, Bartosz; Ligocka, Danuta; Brzeźnicki, Sławomir; Hanke, Wojciech

2016-01-01

In recent years, a trend toward a declining proportion of male births has been noted in several, but not all, industrialized countries. The underlying reason for the drop in the sex ratio is unclear, but one theory states that widespread environmental endocrine disrupting chemicals affecting the male reproductive system in a negative manner could be part of the explanation. The present study was designed to investigate whether the urinary phthalate, pyrethroids and polycyclic aromatic hydrocarbons metabolites concentrations were associated with sperm Y:X ratio. The study population consisted of 194 men aged under 45 years of age who attended infertility clinic in Lodz, Poland for diagnostic purposes with normal semen concentration of 20–300 mln/ml or with slight oligozoospermia (semen concentration of 15–20 mln/ml) (WHO, 1999). The Y:X ratio was assessed by fluorescent in situ hybridization. Urinary concentrations of 1-hydroxypyrene were measured by high performance liquid chromatography, phthalate metabolites were analyzed using a procedure based on the LC-MS/MS methods and metabolites of synthetic pyrethroids were assessed by gas chromatography ion-tap mass spectrometry method. After adjustment for potential confounders (past diseases, age, abstinence, smoking, alcohol consumption, sperm concentration, motility, morphology) 5OH MEHP, CDCCA to TDCCA and 1-OHP was negatively related to Y:X sperm chromosome ratio (p = 0.033, p < 0.001, p = 0.047 respectively). As this is the first study to elucidate the association between the level of metabolites of widespread environmental endocrine disrupting chemicals (phthalates, synthetic pyrethroids, polycyclic aromatic hydrocarbons) on sex chromosome ratio in sperm therefore, these findings require further replication in other populations. - Highlights: • Urinary phthalate metabolites levels were significantly associated with a decrease in Y/X chromosome bearing sperm. • The levels of 1-hydroxypyrene in urine

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).

Diagnostic reference range of κ/λ free light chain ratio to screen for Bence Jones proteinuria is not significantly influenced by GFR.

Science.gov (United States)

Schmidt-Hieltjes, Yvonne; Elshof, Clemens; Roovers, Lian; Ruinemans-Koerts, Janneke

2016-05-01

The aim of our study was to analyse whether the κ/λ free light chain ratio reference range for screening for Bence Jones proteinuria should be dependent on the estimated glomerular filtration rate (eGFR). The serum κ/λ free light chain ratio, eGFR, serum M-protein and Bence Jones protein were measured in 544 patients for whom Bence Jones protein analysis was ordered. In the population of patients without Bence Jones proteinuria or a M-protein (n = 402), there is no gradual increase in κ/λ free light chain ratio with diminishing eGFR. The κ/λ free light chain ratio in this group was 0.56-1.86 (95% interval). With this diagnostic reference range of the κ/λ ratio, 105 of the 110 patients with Bence Jones protein could be identified correctly. Only five patients with Bence Jones proteinuria (free light chain ratio was measured without the presence of Bence Jones proteinuria. A κ/λ free light chain ratio in serum can be used safely and efficiently to select urine samples which should be analysed for Bence Jones proteinuria with an electrophoresis/immunofixation technique. Using this diagnostic reference range, the number of urine samples which should be analysed by electrophoresis/immunofixation could be reduced by 74%. The diagnostic reference interval can be determined best in a group of patients for whom Bence Jones analysis is indicated. For calculation of this reference range, the eGFR value does not need to be taken into account. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Source identification of hydrocarbons following environmental releases

Energy Technology Data Exchange (ETDEWEB)

Birkholz, D.A. [ALS Environmental, Edmonton, AB (Canada)

2010-07-01

Methods of identifying the sources of hydrocarbon contaminations were discussed in this PowerPoint presentation. Laboratories analyze for total petroleum hydrocarbons (TPH) by obtaining chromatograms of observed products. However, many petroleum products provide similar chromatograms. Several independent lines of evidence are needed for the purposes of accurate determination in legal applications. A case study of a lube oil plant spill was used to demonstrate the inconclusiveness of chromatograms and the need to determine petroleum biomarkers. Terpane, sterane, triaromatic sterane, isoprenoid, and alkylcyclohexane analyses were conducted to differentiate between the hydrocarbon samples. The analysis methods are being used with various soil, water, and crab species samples from the BP oil spill. Oil found at the different sites must be directly related to the spill. However, there are 3858 oil and gas platforms currently operating in the Gulf of Mexico. Ratios of biomarkers and polycyclic aromatic hydrocarbons (PAHs) are being developed to generate weight of evidence. A critical difference analysis was also presented. tabs., figs.

Radiolytic degradation of chlorinated hydrocarbons in water

Energy Technology Data Exchange (ETDEWEB)

Wu, Xing-Zheng; Yamamoto, Takeshi [Fukui Univ., Faculty of Engineering, Dept. of Materials Science and Engineering, Fukui (Japan); Hatashita, Masanori [The Wakasa Wan Energy Research Center, Research Dept., Tsuruga, Fukui (Japan)

2002-11-01

Radiolytic degradation of chlorinated hydrocarbons (chloroform, trichloroethylene, and tetrachloroethylene) in water was carried out. Water solutions of the chlorinated hydrocarbons with different concentrations were irradiated with {gamma} rays. Concentrations of methane, ethane, CO, CO{sub 2}, H{sub 2}, and O{sub 2} after the irradiation were determined by gas chromatography. Concentration of chloride ion in the irradiated sample was determined by ion chromatography. Experimental results show that radiolytic degradation of the chlorinated hydrocarbon increased with the radiation dose. Methane, ethane, CO{sub 2}, H{sub 2}, and Cl{sup -} concentrations increased with the radiation dose and the sample concentration. On the other hand, O{sub 2} concentration decreased with the radiation dose and the sample concentration. When sample concentration was high, dissolved oxygen might be not enough for converting most of the C atoms in the sample into CO{sub 2}. This resulted in a low decomposition ratio. Addition of H{sub 2}O{sub 2} as an oxygen resource could increase the decomposition ratio greatly. Furthermore, gas chromatography-mass spectroscopy was applied to identify some intermediates of the radiolytic dehalogenation. Radiolytic degradation mechanisms are also discussed. (author)

Systems and processes for conversion of ethylene feedstocks to hydrocarbon fuels

Science.gov (United States)

Lilga, Michael A.; Hallen, Richard T.; Albrecht, Karl O.; Cooper, Alan R.; Frye, John G.; Ramasamy, Karthikeyan Kallupalayam

2018-04-03

Systems, processes, and catalysts are disclosed for obtaining fuel and fuel blends containing selected ratios of open-chain and closed-chain fuel-range hydrocarbons suitable for production of alternate fuels including gasolines, jet fuels, and diesel fuels. Fuel-range hydrocarbons may be derived from ethylene-containing feedstocks and ethanol-containing feedstocks.

Systems and processes for conversion of ethylene feedstocks to hydrocarbon fuels

Science.gov (United States)

Lilga, Michael A.; Hallen, Richard T.; Albrecht, Karl O.; Cooper, Alan R.; Frye, John G.; Ramasamy, Karthikeyan Kallupalayam

2017-09-26

Systems, processes, and catalysts are disclosed for obtaining fuels and fuel blends containing selected ratios of open-chain and closed-chain fuel-range hydrocarbons suitable for production of alternate fuels including gasolines, jet fuels, and diesel fuels. Fuel-range hydrocarbons may be derived from ethylene-containing feedstocks and ethanol-containing feedstocks.

Utilization of hydrocarbons by cyanobacteria from microbial mats on oily coasts of the Gulf

International Nuclear Information System (INIS)

Al Hasan, R.H.; Sorkhoh, N.A.; Al Bader, D.; Radwan, S.S.

1994-01-01

Several pieces of evidence indicate that Microcoleus chthonoplastes and Phormidium corium, the predominant cyanobacteria in microbial mats on crude oil polluting the Arabian Gulf coasts, contribute to oil degradation by consuming individual n-alkanes. Both cyanobacteria grew phototrophically better in the presence of crude oil or individual n-alkanes than in their absence, indicating that hydrocarbons may have been utilized. This result was true when growth was measured in terms of dry biomass, as well as in terms of the content of biliprotein, the accessory pigment characteristic of cyanobacteria. The phototrophic biomass production by P. corium was directly proportional to the concentration of n-nonadecane (C 19 ) in the medium. The chlorophyll to carotene ratio of hydrocarbon-grown cyanobacteria did not decrease compared to the ratio in the absence of hydrocarbons, indicating that on hydrocarbons the organisms were not stressed. Comparing the fatty acid patterns of total lipids from hydrocarbon-grown cyanobacteria to those of the same organisms grown without hydrocarbons confirms that n-alkanes were taken up and oxidized to fatty acids by both cyanobacteria. (orig.)

Instantaneous wave-free ratio as an alternative to fractional flow reserve in assessment of moderate coronary stenoses: A meta-analysis of diagnostic accuracy studies.

Science.gov (United States)

Maini, Rohit; Moscona, John; Katigbak, Paul; Fernandez, Camilo; Sidhu, Gursukhmandeep; Saleh, Qusai; Irimpen, Anand; Samson, Rohan; LeJemtel, Thierry

2017-12-27

Fractional flow reserve (FFR) remains underutilized due to practical concerns related to the need for hyperemic agents. These concerns have prompted the study of instantaneous wave-free ratio (iFR), a vasodilator-free index of coronary stenosis. Non-inferior cardiovascular outcomes have been demonstrated in two recent randomized clinic trials. We performed this meta-analysis to provide a necessary update of the diagnostic accuracy of iFR referenced to FFR based on the addition of eight more recent studies and 3727 more lesions. We searched the PubMed, EMBASE, Central, ProQuest, and Web of Science databases for full text articles published through May 31, 2017 to identify studies addressing the diagnostic accuracy of iFR referenced to FFR≤0.80. The following keywords were used: "instantaneous wave-free ratio" OR "iFR" AND "fractional flow reserve" OR "FFR." In total, 16 studies comprising 5756 lesions were identified. Pooled diagnostic accuracy estimates of iFR versus FFR≤0.80 were: sensitivity, 0.78 (95% CI, 0.76-0.79); specificity, 0.83 (0.81-0.84); positive likelihood ratio, 4.54 (3.85-5.35); negative likelihood ratio, 0.28 (0.24-0.32); diagnostic odds ratio, 17.38 (14.16-21.34); area under the summary receiver-operating characteristic curve, 0.87; and an overall diagnostic accuracy of 0.81 (0.78-0.84). In conclusion, iFR showed excellent agreement with FFR as a resting index of coronary stenosis severity without the undesired effects and cost of hyperemic agents. When considering along with its clinical outcome data and ease of application, the diagnostic accuracy of iFR supports its use as a suitable alternative to FFR for physiology-guided revascularization of moderate coronary stenoses. We performed a meta-analysis of the diagnostic accuracy of iFR referenced to FFR. iFR showed excellent agreement with FFR as a resting index of coronary stenosis severity without the undesired effects and cost of hyperemic agents. This supports its use as a suitable

Catalysts for the production of hydrocarbons from carbon monoxide and water

Science.gov (United States)

Sapienza, R.S.; Slegeir, W.A.; Goldberg, R.I.

1985-11-06

A method of converting low H/sub 2//CO ratio syngas to carbonaceous products comprising reacting the syngas with water or steam at 200 to 350/sup 0/C in the presence of a metal catalyst supported on zinc oxide. Hydrocarbons are produced with a catalyst selected from cobalt, nickel or ruthenium and alcohols are produced with a catalyst selected from palladium, platinum, ruthenium or copper on the zinc oxide support. The ratio of the reactants are such that for alcohols and saturated hydrocarbons: (2n + 1) greater than or equal to x greater than or equal to O and for olefinic hydrocarbons: 2n greater than or equal to x greater than or equal to O where n is the number of carbon atoms in the product and x is the molar amount of water in the reaction mixture.

Emission factors of polycyclic and nitro-polycyclic aromatic hydrocarbons from residential combustion of coal and crop residue pellets.

Science.gov (United States)

Yang, Xiaoyang; Liu, Shijie; Xu, Yisheng; Liu, Yu; Chen, Lijiang; Tang, Ning; Hayakawa, Kazuichi

2017-12-01

Polycyclic aromatic hydrocarbons (PAHs) and nitro-polycyclic aromatic hydrocarbons (NPAHs) are toxic pollutants mainly produced during fossil fuel combustion. Domestic coal stoves, which emit large amounts of PAHs and NPAHs, are widely used in the Chinese countryside. In this study, emission factors (Efs) for 13 PAH species and 21 NPAH species for four raw coal (three bituminous and one anthracite), one honeycomb briquette, and one crop residue pellet (peanut hulls) samples burned in a typical Chinese rural cooking stove were determined experimentally. The PAH and NPAH Efs for the six fuels were 3.15-49 mg/kg and 0.32-100 μg/kg, respectively. Peanut hulls had very high Efs for both PAHs and NPAHs, and honeycomb briquettes had the lowest Efs. 2-Nitropyrene and 2-nitrofluoranthene, which are NPAHs typically found in secondary organic aerosol, were detected in the emissions from some fuels, suggesting that chemical reactions may have occurred in the dilution tunnel between the flue gas leaving the stove and entering the sampler. The 1-nitropyrene to pyrene diagnostic ratios for coal and peanut hulls were 0.0001 ± 0.0001 and 0.0005, respectively. These were in the same order of magnitude as reference ratios for emissions during coal combustion. The 6-nitrobenzo[a]pyrene to benzo[a]pyrene ratios for the fuels were determined, and the ratios for coal and peanut hulls were 0.0010 ± 0.0001 and 0.0014, respectively. The calculated potential toxic risks indicated that peanut hull emissions were very toxic, especially in terms of NPAHs, compared with emissions from the other fuels. Copyright © 2017 Elsevier Ltd. All rights reserved.

POLYCYCLIC AROMATIC HYDROCARBONS WITH STRAIGHT EDGES AND THE 7.6/6.2 AND 8.6/6.2 INTENSITY RATIOS IN REFLECTION NEBULAE.

Science.gov (United States)

Ricca, Alessandra; Bauschlicher, Charles W; Roser, Joseph E; Peeters, Els

2018-01-01

We have investigated the mid-infrared spectral characteristics of a series of polycyclic aromatic hydrocarbons (PAHs) with straight edges and containing an even or odd number of carbons using density functional theory (DFT). For several even and odd-carbon PAHs, the 8.6/6.2 and 7.6/6.2 intensity ratios computed in emission after the absorption of a 8 eV photon match the observed ratios obtained for three reflection nebulae (RNe), namely NGC 1333, NGC 7023, and NGC 2023. Odd-carbon PAHs are favored, particularly for NGC 1333. Both cations and anions are present with the cations being predominant. Relevant PAHs span sizes ranging from 46 to 103-113 carbons for NGC 7023 and NGC 2023 and from 38 to 127 carbons for NGC 1333 and have symmetries ranging from D 2 h to C s . Our work suggests that even and odd-carbon PAHs with straight edges are viable candidates for the PAH emission seen towards irradiated Photo-Dissociation Regions (PDRs).

Polycyclic Aromatic Hydrocarbons with Straight Edges and the 7.6/6.2 and 8.6/6.2 Intensity Ratios in Reflection Nebulae

Science.gov (United States)

Ricca, Alessandra; Bauschlicher, Charles W., Jr.; Roser, Joseph E.; Peeters, Els

2018-02-01

Using density functional theory, we have investigated the mid-infrared spectral characteristics of a series of polycyclic aromatic hydrocarbons (PAHs) that have straight edges and that contain an even or odd number of carbons. For several even and odd-carbon PAHs, the 8.6/6.2 and 7.6/6.2 intensity ratios computed in emission after the absorption of a 8 eV photon match the observed ratios obtained for three reflection nebulae (RNe), namely NGC 1333, NGC 7023, and NGC 2023. Odd-carbon PAHs are favored, particularly for NGC 1333. Both cations and anions are present, with the cations being predominant. Relevant PAHs span sizes ranging from 46 to 113 carbons for NGC 7023 and NGC 2023 and from 38 to 127 carbons for NGC 1333, and have symmetries ranging from D2h to C s . Our work suggests that even- and odd-carbon PAHs with straight edges are viable candidates for the PAH emission seen toward irradiated photodissociation regions.

Histopathological Diagnostic Value of the IgG4+/IgG+ Ratio of Plasmacytic Infiltration for IgG4-Related Diseases

Science.gov (United States)

Deng, Chuiwen; Li, Wenli; Chen, Si; Zhang, Wen; Li, Jing; Hu, Chaojun; Wen, Xiaoting; Zhang, Fengchun; Li, Yongzhe

2015-01-01

Abstract This article aims to perform a meta-analysis to evaluate the diagnostic value of the immunoglobulin G (IgG)4+/IgG+ ratio of plasmacytic infiltration for IgG4-related diseases. Four databases—EMBASE, ISI Web of Knowledge, PubMed, and the Cochrane Library—were systematically searched. Approximately 200 participants from several studies were included in this research. STATA 11.2 software (Stata Corporation, College Station, TX) and Meta-DiSc 1.4 (Unit of Clinical Biostatistics, Ramon y Cajal Hospital, Madrid, Spain) were used to perform the meta-analysis. Nine studies were included in the meta-analysis. The pooled diagnostic odds ratio was 18.94 [95% confidence interval (CI), 2.89–124.30]. The sensitivity was 58.80% (95% CI, 50.90–66.30) and the specificity was 90.20% (95% CI, 81.20–95.80). The positive and negative likelihood ratios were 3.12 (95% CI, 1.07–9.16) and 0.26 (95% CI, 0.09–0.70), respectively. The area under the curve of the summary receiver-operating characteristic was 0.88. To conclude, the IgG4+/IgG+ ratio of plasmacytic infiltration is modestly effective in diagnosing IgG-related disease. PMID:25738476

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

The diagnostic odds ratio: a single indicator of test performance

NARCIS (Netherlands)

Glas, Afina S.; Lijmer, Jeroen G.; Prins, Martin H.; Bonsel, Gouke J.; Bossuyt, Patrick M. M.

2003-01-01

Diagnostic testing can be used to discriminate subjects with a target disorder from subjects without it. Several indicators of diagnostic performance have been proposed, such as sensitivity and specificity. Using paired indicators can be a disadvantage in comparing the performance of competing

Correlation between the solubility of aromatic hydrocarbons in water and micellar solutions, with their normal boiling points

International Nuclear Information System (INIS)

Almgren, M.; Grieser, F.; Powell, J.R.; Thomas, J.K.

1979-01-01

A linear correlation between the logarithm of the solubility in water of aromatic hydrocarbons and their normal boiling points is shown. Similarly, the logarithm of the distribution ratio of aromatic hydrocarbons in aqueous micellar solution is shown to be linearly related to the boiling points of the hydrocarbons. 2 figures, 2 tables

Characteristics of atmospheric non-methane hydrocarbons in Foshan City, China.

Science.gov (United States)

Tan, Jihua; Guo, Songjun; Ma, Yongliang; He, Kebin; Yang, Fumo; Yu, Yongchang; Wang, Jiewen

2011-12-01

Foshan is the most air-polluted city in Pearl River Delta. Non-methane hydrocarbons (NMHCs) were investigated for the first time in Foshan in winter 2008. Ethene, ethane, ethyne, propane, i-pentane, and toluene were the most abundant hydrocarbons and observed to be higher in Foshan than those in many other cities in China. Different from other cities, ethene and ethane were observed to be the two highest compounds in Foshan. Generally, the most abundant hydrocarbons showed high mixing ratios in the morning (0930-1030 hours), decreased to the lowest level in the afternoon (1430-1530 hours), and increased to higher value in the evening (1930-2030 hours). But i-pentane exhibited a different diurnal pattern with the highest level (13.4 ± 5.8 ppbv) in the afternoon, implying the acceleration of solvent evaporation resulting from higher temperature. Correlation coefficients (R(2) = 66% for n = 6 at 95% confidence level) of the individual hydrocarbons with ethyne and i-pentane indicated vehicular emissions were the main sources of ethene, propene, i-butene, isoprene, benzene and toluene, while gasoline evaporation was responsible for n-pentane, n-hexane, and n-heptane. The good correlation of most of the hydrocarbons with ethyne, indicating vehicular emissions, were the main sources of NMHCs. B/T ratio was 0.36 ± 0.06, implying vehicular emissions acted as the major contributors as well as additional emissions of toluene emitted from solvent usage. According to investigation, it also suggested that LPG leakage was the main source of propane, while NG leakage was responsible for ethane in Foshan City.

Diagnostic pharmaco-scintigraphy with hepatic intra-arterial technetium-99m macroaggregated albumin in the determination of tumour to non-tumour uptake ratio in hepatocellular carcinoma

International Nuclear Information System (INIS)

Lau, W.Y.; Leung, T.W.T.; Chan, M.; Leung, N.W.Y.; Metreweli, C.; Li, A.K.C.

1994-01-01

Between October 1990 and March 1993, 124 patients with hepatocellular carcinoma (HCC) underwent diagnostic pharmaco-scintigraphy with hepatic intraarterial technetium-99m macroaggregated albumin (TcMAA) to determine the tumorous to non-tumorous liver tissue uptake ratio (T/N ratio). There were 110 males and 14 females. Ages ranged from 16 to 73 with a median of 55 years. The range of T/N ratio was 0.7 to 19.3 with a median of 3.8. 12 patients with inoperable HCC were subsequently selected by predetermined criteria to undergo treatment with hepatic intraarterial yttrium-90 microspheres and the T/N ratios in these patients were validated by beta probe dosimetry and liquid scintillation count of multiple liver biopsies. The T/N ratio determined by preoperative diagnostic TcMAA scan corrected well with intraoperative beta probe dosimetry, with coefficient of correlation r = 0.82. Preoperative TcMAA scan also correlated well with liquid scintillation count of biopsy specimens. (author)

Distribution, Source, and Ecological Risk Assessment of Polycyclic Aromatic Hydrocarbons in Surface Sediment of Liaodong Bay, Northeast China

Science.gov (United States)

Xu, Shuang; Tao, Ping; Li, Yuxia; Guo, Qi; Zhang, Yan; Wang, Man; Jia, Hongliang; Shao, Mihua

2018-01-01

Sixteen polycyclic aromatic hydrocarbons (PAHs) were determined in surface sediments from Liaodong Bay, northeast China. The concentration levels of total PAHs (Σ16PAHs) in sediment were 11.0˜249.6 ng·g-1 dry weight (dw), with a mean value of 89.9 ng·g-1 dry weight (dw). From the point of the spatial distribution, high PAHs levels were found in the western areas of Liaodong Bay. In the paper, sources of PAHs were investigated by diagnostic ratios, which indicated that pyrogenic sources were the main sources of PAHs in the sediment of Liaodong Bay. Therefore, selected PAH levels in sediments were compared with Sediments Quality Guidelines (ERM-ERL indexes) for evaluation probable toxic effects on marine organism.

Influence of traffic conditions on polycyclic aromatic hydrocarbon abundance in street dust.

Science.gov (United States)

Xiang, Li; Li, Yingxia; Yang, Zhifeng; Shi, Jianghong

2010-01-01

Polycyclic aromatic hydrocarbon (PAH) concentrations were quantified in sieved street dusts from eight sampling sites with different traffic conditions in Beijing. The parent diagnostic ratio test and multi-regression analysis were used to identify the different PAH pollution sources. Results showed that more than 93% of the cumulative 16 priority pollutant PAHs (Sigma 16EPA-PAH) load was present in street dust with a diameter less than 300 microm across all the sampling sites. The concentration of Sigma 4-6 ring PAHs was 93 to 284% higher than that of Sigma 2-3 ring PAHs for most of the sites except the cycle lane site, indicating the dominance of pyrogenic inputs in street dusts at these sites. Cooking oil is an important PAH source in street dusts for all the sampling sites. Tire debris and vehicle emissions were also identified as significant contributors to the PAH loading in the heavy traffic zone, vehicle parking areas, the frequent brake usage zone, and the construction area.

The use of polynuclear aromatic hydrocarbon (PAH) alkyl homologues in determining petroleum source identification and weathering

International Nuclear Information System (INIS)

Brown, J.S.; Boehm, P.D.; Sauer, T.C.; Wong, W.M.C.

1993-01-01

Techniques utilizing double ratio plots of selected polynuclear aromatic hydrocarbon (PAH) alkyl homologues were used to identify and distinguish crude oils and refined petroleum products from each other and to distinguish petroleum sources in complex pollutant regimes. Petroleum samples were fractionated by high performance liquid chromatography (HPLC) into saturated and aromatic (PAH) hydrocarbon fractions. The saturated hydrocarbon fractions were then analyzed by gas chromatography/flame ionization detection (GC/FID) to obtain a resolved/unresolved alkane fingerprint of each oil. The aromatic fractions of the oils were analyzed by gas chromatography/mass spectrometry (GC/MS) for PAH and selected alkyl homologues. Comparisons of the saturated hydrocarbon fingerprints indicated that some oils were indistinguishable based on the alkane fingerprint alone. Another double ratio plot of the alkyl chrysenes and alkyl dibenzothiophenes was effective in establishing the weathering of oil in environmental samples which were processed using the same analytical techniques, since the dibenzothiophenes are degraded more rapidly than the chrysenes. The application of selected ratios in oil spill source identification in complex environmental samples from Suisin Bay California and Boston Harbor are discussed. The use of ratios to measure the extent of weathering in oil spill samples from Prince William Sound and the Gulf of Alaska is examined

Environmental forensic principals for sources allocation of polycyclic aromatic hydrocarbons

International Nuclear Information System (INIS)

O'Sullivan, G.; Martin, E.; Sandau, C.D.

2008-01-01

Polycyclic aromatic hydrocarbons (PAH) are organic compounds which include only carbon and hydrogen with a fused ring structure containing at least two six-sided benzene rings but may also contain additional fused rings that are not six-sided. The environmental forensic principals for sources allocation of PAHs were examined in this presentation. Specifically, the presentation addressed the structure and physiochemical properties of PAHs; sources and sinks; fate and behaviour; analytical techniques; conventional source identification techniques; and toxic equivalent fingerprinting. It presented a case study where residents had been allegedly exposed to dioxins, PAHs and metals released from a railroad tie treatment plant. The classification of PAHs is governed by thermodynamic properties such as biogenic, petrogenic, and pyrogenic properties. A number of techniques were completed, including chemical fingerprinting; molecular diagnostic ratios; cluster analysis; principal component analysis; and TEF fingerprinting. These techniques have shown that suspected impacted sites do not all share similar PAH signatures indicating the potential for various sources. Several sites shared similar signatures to background locations. tabs., figs

Chemical characterization and stable carbon isotopic composition of particulate Polycyclic Aromatic Hydrocarbons issued from combustion of 10 Mediterranean woods

Directory of Open Access Journals (Sweden)

A. Guillon

2013-03-01

Full Text Available The objectives of this study were to characterize polycyclic aromatic hydrocarbons from particulate matter emitted during wood combustion and to determine, for the first time, the isotopic signature of PAHs from nine wood species and Moroccan coal from the Mediterranean Basin. In order to differentiate sources of particulate-PAHs, molecular and isotopic measurements of PAHs were performed on the set of wood samples for a large panel of compounds. Molecular profiles and diagnostic ratios were measured by gas chromatography/mass spectrometry (GC/MS and molecular isotopic compositions (δ13C of particulate-PAHs were determined by gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS. Wood species present similar molecular profiles with benz(aanthracene and chrysene as dominant PAHs, whereas levels of concentrations range from 1.8 to 11.4 mg g−1 OC (sum of PAHs. Diagnostic ratios are consistent with reference ratios from literature but are not sufficient to differentiate the species of woods. Concerning isotopic methodology, PAH molecular isotopic compositions are specific for each species and contrary to molecular fingerprints, significant variations of δ13C are observed for the panel of PAHs. This work allows differentiating wood combustion (with δ13CPAH = −28.7 to −26.6‰ from others origins of particulate matter (like vehicular exhaust using isotopic measurements but also confirms the necessity to investigate source characterisation at the emission in order to help and complete source assessment models. These first results on woodburnings will be useful for the isotopic approach to source tracking.

Effects of P/Ni ratio and Ni content on performance of γ-Al2O3-supported nickel phosphides for deoxygenation of methyl laurate to hydrocarbons

Science.gov (United States)

Zhang, Zhena; Tang, Mingxiao; Chen, Jixiang

2016-01-01

γ-Al2O3-supported nickel phosphides (mNi-Pn) were prepared by the TPR method and tested for the deoxygenation of methyl laurate to hydrocarbons. The effects of the P/Ni ratio (n = 1.0-2.5) and Ni content (m = 5-15 wt.%) in the precursors on their structure and performance were investigated. Ni/γ-Al2O3 was also studied for comparison. It was found that the formation of AlPO4 in the precursor inhibited the reduction of phosphate and so the formation of nickel phosphides. With increasing the P/Ni ratio and Ni content, the Ni, Ni3P, Ni12P5 and Ni2P phases orderly formed, accompanying with the increases of their particle size and the amount of weak acid sites (mainly due to P-OH group), while the CO uptake and the amount of medium strong acid sites (mainly related to Ni sites) reached maximum on 10%Ni-P1.5. In the deoxygenation reaction, compared with Ni/γ-Al2O3, the mNi-Pn catalysts showed much lower activities for decarbonylation, Csbnd C hydrogenolysis and methanation due to the ligand and ensemble effects of P. The conversion and the selectivity to n-C11 and n-C12 hydrocarbons achieved maximum on 10%Ni-P 2.0 for the 10%Ni-Pn catalysts and on 8%Ni-P2.0 for the mNi-P2.0 catalysts, while the turnover frequency (TOF) of methyl laurate mainly increased with the P/Ni ratio and Ni content. We propose that TOF was influenced by the nickel phosphide phases, the catalyst acidity and the particle size as well as the synergetic effect between the Ni site and acid site. Again, the hydrodeoxygenation pathway of methyl laurate was promoted with increasing P/Ni ratio and Ni content, ascribed to the phase change in the order of Ni, Ni3P, Ni12P5 and Ni2P in the prepared catalysts.

Diagnostic value of transmural perfusion ratio derived from dynamic CT-based myocardial perfusion imaging for the detection of haemodynamically relevant coronary artery stenosis

Energy Technology Data Exchange (ETDEWEB)

Coenen, Adriaan; Lubbers, Marisa M.; Dedic, Admir; Chelu, Raluca G.; Geuns, Robert-Jan M. van; Nieman, Koen [Erasmus University Medical Center, Department of Radiology, Rotterdam (Netherlands); Erasmus University Medical Center, Department of Cardiology, Rotterdam (Netherlands); Kurata, Akira; Kono, Atsushi; Dijkshoorn, Marcel L. [Erasmus University Medical Center, Department of Radiology, Rotterdam (Netherlands); Rossi, Alexia [Erasmus University Medical Center, Department of Radiology, Rotterdam (Netherlands); Barts Health NHS Trust, NIHR Cardiovascular Biomedical Research Unit at Barts, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London and Department of Cardiology, London (United Kingdom)

2017-06-15

To investigate the additional value of transmural perfusion ratio (TPR) in dynamic CT myocardial perfusion imaging for detection of haemodynamically significant coronary artery disease compared with fractional flow reserve (FFR). Subjects with suspected or known coronary artery disease were prospectively included and underwent a CT-MPI examination. From the CT-MPI time-point data absolute myocardial blood flow (MBF) values were temporally resolved using a hybrid deconvolution model. An absolute MBF value was measured in the suspected perfusion defect. TPR was defined as the ratio between the subendocardial and subepicardial MBF. TPR and MBF results were compared with invasive FFR using a threshold of 0.80. Forty-three patients and 94 territories were analysed. The area under the receiver operator curve was larger for MBF (0.78) compared with TPR (0.65, P = 0.026). No significant differences were found in diagnostic classification between MBF and TPR with a territory-based accuracy of 77 % (67-86 %) for MBF compared with 70 % (60-81 %) for TPR. Combined MBF and TPR classification did not improve the diagnostic classification. Dynamic CT-MPI-based transmural perfusion ratio predicts haemodynamically significant coronary artery disease. However, diagnostic performance of dynamic CT-MPI-derived TPR is inferior to quantified MBF and has limited incremental value. (orig.)

Apparatus and method for rapid separation and detection of hydrocarbon fractions in a fluid stream

Science.gov (United States)

Sluder, Charles S.; Storey, John M.; Lewis, Sr., Samuel A.

2013-01-22

An apparatus and method for rapid fractionation of hydrocarbon phases in a sample fluid stream are disclosed. Examples of the disclosed apparatus and method include an assembly of elements in fluid communication with one another including one or more valves and at least one sorbent chamber for removing certain classifications of hydrocarbons and detecting the remaining fractions using a detector. The respective ratios of hydrocarbons are determined by comparison with a non separated fluid stream.

GOM Deepwater Horizon Oil Spill: A Time Series Analysis of Variations in Spilled Hydrocarbons

Science.gov (United States)

Palomo, C. M.; Yan, B.

2013-12-01

An estimated amount of 210 million gallons of crude oil was released into the Gulf of Mexico (GOM) from April 20th to July 15th 2010 during the Deepwater Horizon oil rig explosion. The spill caused a tremendous financial, ecological, environmental and health impact and continues to affect the GOM today. Variations in hydrocarbons including alkanes, hopanes and poly-cyclic aromatic hydrocarbons (PAHs) can be analyzed to better understand the oil spill and assist in oil source identification. Twenty-one sediment samples*, two tar ball samples and one surface water oil sample were obtained from distinct locations in the GOM and within varying time frames from May to December 2010. Each sample was extracted through the ASE 200 solvent extractor, concentrated down under nitrogen gas, purified through an alumina column, concentrated down again with nitrogen gas and analyzed via GC X GC-TOF MS. Forty-one different hydrocarbons were quantified in each sample. Various hydrocarbon 'fingerprints,' such as parental :alkylate PAH ratios, high molecular weight PAHs: low molecular weight alkane ratios, and carbon preference index were calculated. The initial objective of this project was to identify the relative hydrocarbon contributions of petrogenic sources and combustion sources. Based on the calculated ratios, it is evident that the sediment core taken in October of 2010 was greatly affected by combustion sources. Following the first month of the spill, oil in the gulf was burned in attempts to contain the spill. Combustion related sources have quicker sedimentation rates, and hydrocarbons from a combustion source essentially move into deeper depths quicker than those from a petrogenic source, as was observed in analyses of the October 2010 sediment. *Of the twenty-one sediment samples prepared, nine were quantified for this project.

Aliphatic hydrocarbons in surface sediments from South China Sea off Kuching Division, Sarawak

International Nuclear Information System (INIS)

Hafidz Yusoff; Zaini Assim; Samsur Mohamad

2012-01-01

Eighteen surface sediment samples collected from South China Sea off Kuching Division, Sarawak were analyzed for aliphatic hydrocarbons. These hydrocarbons were recovered from sediment by Soxhlet extraction method and then analyzed using gas chromatography equipped with mass spectrometer (GC/ MS). Total concentrations of aliphatic hydrocarbons in surface sediments from South China Sea off Kuching division are ranged from 35.6 μg/ g to 1466.1 μg/ g dry weights. The sediments collected from Bako Bay, Kuching showed high concentrations of total aliphatic hydrocarbons. Several molecular indices were used to predict the predominant sources of hydrocarbons. Carbon preference index (CPI) value revealed widespread anthropogenic input in this study area (CPI= 0 to 4.1). The ratio of C 31 / C 19 and C 29 / C 31 indicated that major input of aliphatic hydrocarbon mostly transfer by lateral input to the marine environment than atmospheric movements. Generally, the concentrations of aliphatic hydrocarbons in sediment from South China Sea off Kuching division are generally higher compare to other area in the world. (author)

Application of compound specific 13C isotope investigations of chlorinated hydrocarbons in contaminated groundwaters

International Nuclear Information System (INIS)

Osenbrueck, K.; Heidinger, M.; Voropaev, A.; Ertl, S.; Eichinger, L.

2002-01-01

Full text: Chlorinated hydrocarbons are one of the most common pollutants found in groundwater. Due to complex contamination situations with overlapping contamination plumes the assessment of the organic contaminants requires the installation of expensive observation wells and high analytical effort. Here the determination of the stable isotope ratio 13 C/ 12 C of the organic compounds offers a promising and efficient tool to investigate the origin and the biodegradation characteristics of the chlorinated hydrocarbons in groundwater. The application of the method is based on characteristic isotope fingerprints, differing in chlorinated solvents. This isotope fingerprint is derived from different production pathways and is not influenced by transport or by retardation processes in the underground. Due to the fact, that two different contaminations can easily be distinguished by isotope ratios, an improved distinction of spatially and temporally different contamination plumes might be possible. In course of biologically mediated degradation processes a shift of the isotope ratios between the precursor and the product can frequently be observed, such as with denitrification or sulfate reduction processes. The isotope fractionation is due to a preferential reaction of the bonds formed by the lighter isotopes and leads to a progressive enrichment of the heavy isotopes in the precursor while the product becomes depleted in the heavy isotopes. Biological degradation of the highly chlorinated hydrocarbons is due to a co-metabolic dechlorinisation. Tetrachloroethene (PCE) for example degrades under anoxic conditions via trichloroethene (TCE) to cis-1,2-dichloroethene (cDCE). Subsequent degradation to vinyl chloride (VC) and ethene may appear under aerobic as well as reducing environments depending on the site specific conditions. In several laboratory studies it has been shown, that biodegradation of the chlorinated hydrocarbons is accompanied by an isotope fractionation of

Natural attenuation of diesel aliphatic hydrocarbons in contaminated agricultural soil

International Nuclear Information System (INIS)

Serrano, Antonio; Gallego, Mercedes; Gonzalez, Jose Luis; Tejada, Manuel

2008-01-01

A diesel fuel spill at a concentration of 1 L m -2 soil was simulated on a 12 m 2 plot of agricultural land, and natural attenuation of aliphatic hydrocarbons was monitored over a period of 400 days following the spill after which the aliphatic hydrocarbon concentrations were found to be below the legal contamination threshold for soil. The main fraction of these compounds (95%) remained at the surface layer (0-10 cm). Shortly after the spill (viz. between days 0 and 18), evaporation was the main origin of the dramatic decrease in pollutant concentrations in the soil. Thereafter, soil microorganisms used aliphatic hydrocarbons as sources of carbon and energy, as confirmed by the degradation ratios found. Soil quality indicators, soil microbial biomass and dehydrogenase activity, regained their original levels about 200 days after the spill. - The effect of aliphatic hydrocarbons contamination on soil quality was monitored over a period of 400 days after a Diesel fuel spill

Methanogenic degradation of petroleum hydrocarbons in subsurface environments remediation, heavy oil formation, and energy recovery.

Science.gov (United States)

Gray, N D; Sherry, A; Hubert, C; Dolfing, J; Head, I M

2010-01-01

Hydrocarbons are common constituents of surface, shallow, and deep-subsurface environments. Under anaerobic conditions, hydrocarbons can be degraded to methane by methanogenic microbial consortia. This degradation process is widespread in the geosphere. In comparison with other anaerobic processes, methanogenic hydrocarbon degradation is more sustainable over geological time scales because replenishment of an exogenous electron acceptor is not required. As a consequence, this process has been responsible for the formation of the world's vast deposits of heavy oil, which far exceed conventional oil assets such as those found in the Middle East. Methanogenic degradation is also a potentially important component of attenuation in hydrocarbon contamination plumes. Studies of the organisms, syntrophic partnerships, mechanisms, and geochemical signatures associated with methanogenic hydrocarbon degradation have identified common themes and diagnostic markers for this process in the subsurface. These studies have also identified the potential to engineer methanogenic processes to enhance the recovery of energy assets as biogenic methane from residual oils stranded in petroleum systems. Copyright 2010 Elsevier Inc. All rights reserved.

A search for direct hydrocarbon indicators in the Formby area

International Nuclear Information System (INIS)

Busby, J.P.; Peart, R.J.; Green, C.A.; Ogilvy, R.D.; Williamson, J.P.

1991-01-01

It has been proposed that the high- frequency, low-amplitude magnetic anomalies found over some hydrocarbon deposits are due to long-term microseepage of hydrocarbons into iron-rich sedimentary roof rocks, with subsequent precipitation of diagenetic magnetite or pyrrhotite at or near the water-table. Aerogeophysical data sets, comprising both magnetic and gamma-ray spectrometer measurements, over the Formby, oil-field, Lancashire, U.K., have been analyzed for hydrocarbon-related anomalies. Detailed ground magnetic traverses were also made to investigate some of the aeromagnetic anomalies. No hydrocarbon-induced magnetic anomalies were detected. The majority of the high-frequency events occurring in the aeromagnetic data correlated with cultural features, others were attributed to artifacts of the data processing. In particular there were no extensive areas of high-frequency, low-amplitude anomalies as might be expected from authigenic magnetic minerals. Borehole chippings from inside and outside the oil-field were examined. Anomalies were found to be related to hydrological conditions and to the distribution of surficial deposits. Attempts to suppress the influence of the drift geology had only limited success. In this paper, it is concluded that the effectiveness of high-resolution aeromagnetic onshore surveys for direct hydrocarbon detection has yet to be established. In particular, the anomaly found over the Formby oil-field was caused by the cumulative effect of borehole casing. Similar cultural contamination by oil- field equipment may explain some of the anomalies discovered over hydrocarbon deposits in North America. It is also unlikely that the spectromagnetic method can be applied diagnostically in any but the most simple and drift-free geological environments

Assessing the ecological risk of polycyclic aromatic hydrocarbons in sediments at Langkawi Island, Malaysia.

Science.gov (United States)

Nasher, Essam; Heng, Lee Yook; Zakaria, Zuriati; Surif, Salmijah

2013-01-01

Tourism-related activities such as the heavy use of boats for transportation are a significant source of petroleum hydrocarbons that may harm the ecosystem of Langkawi Island. The contamination and toxicity levels of polycyclic aromatic hydrocarbon (PAH) in the sediments of Langkawi were evaluated using sediment quality guidelines (SQGs) and toxic equivalent factors. Ten samples were collected from jetties and fish farms around the island in December 2010. A gas chromatography/flame ionization detector (GC/FID) was used to analyse the 18 PAHs. The concentration of total PAHs was found to range from 869 ± 00 to 1637 ± 20 ng g⁻¹ with a mean concentration of 1167.00 ± 24 ng g⁻¹, lower than the SQG effects range-low (3442 ng g⁻¹). The results indicated that PAHs may not cause acute biological damage. Diagnostic ratios and principal component analysis suggested that the PAHs were likely to originate from pyrogenic and petrogenic sources. The toxic equivalent concentrations of the PAHs ranged from 76.3 to 177 ng TEQ/g d.w., which is lower compared to similar studies. The results of mean effects range-median quotient of the PAHs were lower than 0.1, which indicate an 11% probability of toxicity effect. Hence, the sampling sites were determined to be the low-priority sites.

Bio-concentration of Polycyclic Aromatic Hydrocarbons in the grey Mangrove (Avicennia marina along eastern coast of the Red Sea

Directory of Open Access Journals (Sweden)

El-Amin Bashir M.

2017-12-01

Full Text Available There are numerous sources of chemical pollutants which can impact the mangrove ecosystem through adjacent waters, industrial and sewage discharges and air depositions. Polycyclic aromatic hydrocarbons (PAHs are semi volatile ubiquitous anthropogenic pollutants detected in all environmental compartments. In the monitoring framework for the mangrove ecosystem along the Red Sea coast of Saudi Arabia, nine mangrove stands were examined for the accumulation of PAHs. Polycyclic aromatic hydrocarbons were measured using Gas Chromatography-Mass Spectrometry (GC-MS. The mean values detected for total PAHs in sediments, roots and leaf were 2.98, 8.57 and 23.43 ng/g respectively. The trend of the total PAHs concentration in all sites showed the descending order: leaf > roots > sediments. Beside the sandy nature of the sediments, the presences of all stands in remote areas fare from the direct anthropogenic effects lead to these relative low values. PAH bio-concentration factors for leaf are two to three magnitudes higher than that in roots, suggesting atmosphere deposition /leaf uptake mechanism in addition to the sediment/root mechanism. The diagnostic ratios revealed that the sources of PAHs are mainly pyrogenic.

Characterization of polycyclic aromatic hydrocarbon emissions in the particulate and gas phase from smoldering mosquito coils containing various atomic hydrogen/carbon ratios

Energy Technology Data Exchange (ETDEWEB)

Yang, Tzu-Ting, E-mail: d89844001@ntu.edu.tw [Department of Environmental Engineering and Health, Yuanpei University, No. 306, Yuanpei St., Hsin Chu 30015, Taiwan (China); Lin, Shaw-Tao [Department of Applied Chemistry, Providence University, No. 200 Chung-Chi Rd., Salu Dist., Taichung City 43301, Taiwan (China); Lin, Tser-Sheng [Department of Safety, Health, and Environmental Engineering, National United University, 2 Lien Da, Maioli 360, Taiwan (China); Chung, Hua-Yi [Department of Environmental Engineering and Health, Yuanpei University, No. 306, Yuanpei St., Hsin Chu 30015, Taiwan (China)

2015-02-15

The polycyclic aromatic hydrocarbon emissions in particulate and gas phases generated from smoldering mosquito coils containing various atomic H/C ratios were examined. Five types of mosquito coils were burned in a test chamber with a total airflow rate of 8.0 L/min at a constant relative humidity and temperature. The concentrations of individual PAHs were determined using the GC/MS technique. Among the used mosquito coils, the atomic H/C ratio ranged from 1.23 to 1.57, yielding total mass, gaseous, and particulate PAH emission factors of 28.17–78.72 mg/g, 26,139.80–35,932.98 and 5735.22–13,431.51 ng/g, respectively. The various partitions of PAHs in the gaseous and particulate phases were in the ranges, 70.26–83.70% and 16.30–29.74% for the utilized mosquito coils. The carcinogenic potency of PAH emissions in the particulate phase (203.82–797.76 ng/g) was approximately 6.92–25.08 times higher than that of the gaseous phase (26.27–36.07 ng/g). Based on the analyses of PAH emissions, mosquito coils containing the lowest H/C ratio, a low oxygen level, and additional additives (i.e., CaCO{sub 3}) are recommended for minimizing the production of total PAH emission factors and carcinogenic potency. - Highlights: • PAHs emissions are influenced by mosquito coils containing various atomic H/C ratios. • The PAHs generated by burning mosquito coils mainly occur in the gaseous phase. • Total TEQ emission factors of PAHs mainly consisted of the particulate phase (> 87%). • The BaP and BaA accounted for 71.13–77.28% of the total TEQ emission factors. • Special PAH ratios were regarded as characteristic ratios for burning mosquito coil.

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.

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.

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...

Fast co-pyrolysis of waste newspaper with high-density polyethylene for high yields of alcohols and hydrocarbons.

Science.gov (United States)

Chen, Weimin; Shi, Shukai; Chen, Minzhi; Zhou, Xiaoyan

2017-09-01

Waste newspaper (WP) was first co-pyrolyzed with high-density polyethylene (HDPE) using pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) to enhance the yields of alcohols and hydrocarbons. The effects of WP: HDPE feed ratio (100:0, 75:25, 50:50, 25:75, 0:100) and temperature (500-800°C) on products distribution were investigated and the interaction mechanism during co-pyrolysis was also proposed. Maximum yields of alcohols and hydrocarbons reached 85.88% (feed ratio 50:50wt.%, 600°C). Hydrogen supplements and deoxidation by HDPE and subsequently fragments recombination result in the conversion of aldehydes and ketones into branched hydrocarbons. Radicals from WP degradation favor the secondary crack for HDPE products resulting in the formation of linear hydrocarbons with low carbon number. Hydrocarbons with activated radical site from HDPE degradation were interacted with hydroxyl from WP degradation promoting the formation of linear long chain alcohols. Moreover, co-pyrolysis significantly enhanced condensable oil qualities, which were close to commercial diesel No. 0. Copyright © 2017 Elsevier Ltd. All rights reserved.

Hydrocarbon Source Signatures in Houston, Texas: Influence of the Petrochemical Industry

Energy Technology Data Exchange (ETDEWEB)

Jobson, B Tom T; Berkowitz, Carl M; Kuster, W C; Goldan, P D; Williams, E J; Fesenfeld, F; Apel, Eric; Karl, Thomas G; Lonneman, William A; Riemer, D

2004-12-22

Observations of C1-C10 hydrocarbon mixing ratios measured by in-situ instrumentation at the La Porte super site during the TexAQS 2000 field experiment are reported. The La Porte data were compared to a roadway vehicle exhaust signature obtained from canister samples collected in the Houston Washburn tunnel during the same summer to better understand the impact of petrochemical emissions of hydrocarbons at the site. It is shown that the abundance of ethene, propene, 1-butene, C2-C4 alkanes, hexane, cyclohexane, methylcyclohexane, isopropylbenzene, and styrene at La Porte were systematically impacted by petrochemical industry emissions. Coherent power law relationships between frequency distribution widths of hydrocarbon mixing ratios and their local lifetimes clearly identify two major source groups, roadway vehicle emissions and industrial emissions. Distributions of most aromatics and long chain alkanes were consistent with roadway vehicle emissions as the dominant source. Airmass reactivity was generally dominated by C1-C3 aldehydes. Propene and ethene sometimes dominated air mass reactivity with HO loss frequencies often greater than 10 s-1. Ozone mixing ratios near 200 ppbv were observed on two separate occasions and these air masses appear to have been impacted by industrial emissions of alkenes from the Houston Ship Channel. The La Porte data provide evidence of the importance of industrial emissions of ethene and propene on air masses reactivity and ozone formation in Houston.

Diagnostic Evaluation of Effective Thyroxine Ratio

International Nuclear Information System (INIS)

Lee, Myung Chul; Choi, Sang Jae; Ro, Heung Kyu; Lee, Hong Kyu; Koh, Chang Soon; Lee, Mun Ho

1975-01-01

The purpose of the present study is to evaluate the diagnostic value of the ETR test as compared to other thyroid function tests in normal persons, patients with thyroid disorders and patients with alterations of thyroxine-binding proteins. The ETR values were obtained from 35 cases as normal control, 63 hyperthyroid patients, 56 euthyroid patients, 23 hypothyroid patients, 10 pregnant women, 5 women taking oral contraceptive medication, 8 liver cirrhosis patients and 4 nephrotic syndrome patients. The results obtained were as follows. 1) The mean value of ETR obtained from the normal controls was 0.99±0.06. 2) The mean ETR values of various thyroid states were 1.25±0.16 in hyperthyroidism, 0.99±0.08 in euthyroidism and 0.82±0.05 in hypothyroidism and significant difference was found between these groups. 3) Seven out of 63 hyperthyroid patients (11.1%) and 2 out of 23 hypothyroid patients (8.7%) had ETR values within normal range and among the 56 euthyroid patients 6 (10.7%) had ETR values outside normal range, so the diagnostic compatibility of ETR was 89.4% in thyroid diseases. 4) Even though the ETR value was well correlated with 131 I-thyroid uptake rate, serum T 3 resin uptake rate and serum T 4 , a high positive correlation was found (r=0.79) between ETR and T 7 . 5) The mean ETR values from patients with alteration in TBG binding capacity were 0.99±0.05 in pregnant women, 0.98±0.04 in women with oral contraceptive medication, 1.04±0.09 in liver cirrhosis patients and 0.94±0.02 in nephrotic syndrome patients and most of them (85.2%) had ETR values within normal range. Our results, therefore, suggests that the ETR estimation does offer the simplest and most reliable single procedure for the screening and diagnosis of various thyroid diseases as a indirect indicator of serum-free thyroxine concentration without essential influence of changes in the thyroxine-binding proteins in serum.

Diagnostic Evaluation of Effective Thyroxine Ratio

Energy Technology Data Exchange (ETDEWEB)

Lee, Myung Chul; Choi, Sang Jae; Ro, Heung Kyu; Lee, Hong Kyu; Koh, Chang Soon; Lee, Mun Ho [Seoul National University College of Medicine, Seoul (Korea, Republic of)

1975-09-15

The purpose of the present study is to evaluate the diagnostic value of the ETR test as compared to other thyroid function tests in normal persons, patients with thyroid disorders and patients with alterations of thyroxine-binding proteins. The ETR values were obtained from 35 cases as normal control, 63 hyperthyroid patients, 56 euthyroid patients, 23 hypothyroid patients, 10 pregnant women, 5 women taking oral contraceptive medication, 8 liver cirrhosis patients and 4 nephrotic syndrome patients. The results obtained were as follows. 1) The mean value of ETR obtained from the normal controls was 0.99+-0.06. 2) The mean ETR values of various thyroid states were 1.25+-0.16 in hyperthyroidism, 0.99+-0.08 in euthyroidism and 0.82+-0.05 in hypothyroidism and significant difference was found between these groups. 3) Seven out of 63 hyperthyroid patients (11.1%) and 2 out of 23 hypothyroid patients (8.7%) had ETR values within normal range and among the 56 euthyroid patients 6 (10.7%) had ETR values outside normal range, so the diagnostic compatibility of ETR was 89.4% in thyroid diseases. 4) Even though the ETR value was well correlated with {sup 131}I-thyroid uptake rate, serum T{sub 3} resin uptake rate and serum T{sub 4}, a high positive correlation was found (r=0.79) between ETR and T{sub 7}. 5) The mean ETR values from patients with alteration in TBG binding capacity were 0.99+-0.05 in pregnant women, 0.98+-0.04 in women with oral contraceptive medication, 1.04+-0.09 in liver cirrhosis patients and 0.94+-0.02 in nephrotic syndrome patients and most of them (85.2%) had ETR values within normal range. Our results, therefore, suggests that the ETR estimation does offer the simplest and most reliable single procedure for the screening and diagnosis of various thyroid diseases as a indirect indicator of serum-free thyroxine concentration without essential influence of changes in the thyroxine-binding proteins in serum.

Characteristics of atmospheric non-methane hydrocarbons during high PM 10 episodes and normal days in Foshan, China

Science.gov (United States)

Guo, Songjun; Tan, Jihua; Ma, Yongliang; Yang, Fumo; Yu, Yongchan; Wang, Jiewen

2011-08-01

Atmospheric non-methane hydrocarbons (NMHCs) were firstly studied during high PM 10 episodes and normal days in December 2008 in Foshan, China. Ethyne, ethene, i-pentane, toluene, ethane and propane are six abundant hydrocarbons, accounting for round 80% of total NMHCs. Both diurnal variations and concentration ratios of morning (evening)/afternoon implied vehicular emission for most hydrocarbons. Correlation coefficients (R 2) of ethene, propene, i-butene, benzene, toluene and i-/n-butanes with ethyne were 0.60-0.88 (they were 0.64-0.88 during high PM 10 episode and 0.60-0.85 in normal days) except for ethene and i-butene in normal days, indicating these hydrocarbons are mainly related to vehicular emission. It suggests liquefied petroleum gas (LPG) and natural gas (NG) leakages are responsible for propane and ethane, respectively. The measured mean benzene/toluene (B/T) ratio (wt/wt) was 0.45 ± 0.29 during total sampling periods together with R 2 analysis, again indicating vehicular emission is main contributor to ambient hydrocarbons. And the lower B/T ratio (0.29 ± 0.11) during high PM 10 episodes than that (0.75 ± 0.29) in normal days is likely caused by air transport containing low B/T value (0.23) from Guangzhou as well as solvent application containing toluene in Foshan.

Enhancement of aromatic and saturated hydrocarbon by modified ...

African Journals Online (AJOL)

Three sediment samples collected from the Qua Iboe River System and eighteen different column packing ratios of silica gel and alumina were used in this investigation. The variation of the composition of the stationary phase (silica gel and alumina, SA) gave different yields of aromatic and saturated hydrocarbons. In all the ...

Temperature effect on hydrocarbon deposition on molybdenum mirrors under ITER-relevant long-term plasma operation

NARCIS (Netherlands)

Rapp, J.; van Rooij, G. J.; Litnovsky, A.; Marot, L.; De Temmerman, G.; Westerhout, J.; Zoethout, E.

2009-01-01

Optical diagnostics in ITER will rely on mirrors near the plasma and the deterioration of the reflectivity is a concern. The effect of temperature on the deposition efficiency of hydrocarbons under long-term operation conditions similar to ITER was investigated in the linear plasma generator

Composite catalyst for carbon monoxide and hydrocarbon oxidation

Science.gov (United States)

Liu, Wei; Flytzani-Stephanopoulos, Maria

1996-01-01

A method and composition for the complete oxidation of carbon monoxide and/or hydrocarbon compounds. The method involves reacting the carbon monoxide and/or hydrocarbons with an oxidizing agent in the presence of a metal oxide composite catalyst. The catalyst is prepared by combining fluorite-type oxygen ion conductors with active transition metals. The fluorite oxide, selected from the group consisting of cerium oxide, zirconium oxide, thorium oxide, hafnium oxide, and uranium oxide, and may be doped by alkaline earth and rare earth oxides. The transition metals, selected from the group consisting of molybdnum, copper, cobalt, maganese, nickel, and silver, are used as additives. The atomic ratio of transition metal to fluorite oxide is less than one.

Deciphering biodegradation effects on light hydrocarbons in crude oils using their stable carbon isotopic composition: a case study from the Gullfaks oil field, offshore Norway

OpenAIRE

Andrea Vieth-Hillebrand [Vieth; Heinz Wilkes

2006-01-01

Compound-specific isotope analysis has become an important tool in environmental studies and is an especially powerful way to evaluate biodegradation of hydrocarbons. Here, carbon isotope ratios of light hydrocarbons were used to characterise in-reservoir biodegradation in the Gullfaks oil field, offshore Norway. Increasing biodegradation, as characterised, for example, by increasing concentration ratios of Pr/n-C17 and Ph/n-C18, and decreasing concentrations of individual light hydrocarbons ...

Isotopic 32S/33S ratio as a diagnostic of presolar grains from novae

Directory of Open Access Journals (Sweden)

A. Parikh

2014-10-01

Full Text Available Measurements of sulphur isotopes in presolar grains can help to identify the astrophysical sites in which these grains were formed. A more precise thermonuclear rate of the 33S(p,γ34Cl reaction is required, however, to assess the diagnostic ability of sulphur isotopic ratios. We have studied the 33S(3He,d34Cl proton-transfer reaction at 25 MeV using a high-resolution quadrupole–dipole–dipole–dipole magnetic spectrograph. Deuteron spectra were measured at ten scattering angles between 10° and 55°. Twenty-four levels in 34Cl over Ex=4.6–5.9 MeV were observed, including three levels for the first time. Proton spectroscopic factors were extracted for the first time for levels above the 33S + p threshold, spanning the energy range required for calculations of the thermonuclear 33S(p,γ34Cl rate in classical nova explosions. We have determined a new 33S(p,γ34Cl rate using a Monte Carlo method and have performed new hydrodynamic nova simulations to determine the impact on nova nucleosynthesis of remaining nuclear physics uncertainties in the reaction rate. We find that these uncertainties lead to a factor of ≤5 variation in the 33S(p,γ34Cl rate over typical nova peak temperatures, and variation in the ejected nova yields of SCa isotopes by ≤20%. In particular, the predicted 32S/33S ratio is 110–130 for the nova model considered, compared to 110–440 with previous rate uncertainties. As recent type II supernova models predict ratios of 130–200, the 32S/33S ratio may be used to distinguish between grains of nova and supernova origin.

Ultraviolet Studies of Jupiter's Hydrocarbons and Aerosols from Galileo

Science.gov (United States)

Gladstone, G. Randall

2001-01-01

This is the final report for this project. The purpose of this project was to support PI Wayne Pryor's effort to reduce and analyze Galileo UVS (Ultraviolet Spectrometer) data under the JSDAP program. The spectral observations made by the Galileo UVS were to be analyzed to determine mixing ratios for important hydrocarbon species (and aerosols) in Jupiter's stratosphere as a function of location on Jupiter. Much of this work is still ongoing. To date, we have concentrated on analyzing the variability of the auroral emissions rather than the absorption signatures of hydrocarbons, although we have done some work in this area with related HST-STIS data.

Diesel-related hydrocarbons can dominate gas phase reactive carbon in megacities

Directory of Open Access Journals (Sweden)

R. E. Dunmore

2015-09-01

Full Text Available Hydrocarbons are key precursors to two priority air pollutants, ozone and particulate matter. Those with two to seven carbons have historically been straightforward to observe and have been successfully reduced in many developed cities through air quality policy interventions. Longer chain hydrocarbons released from diesel vehicles are not considered explicitly as part of air quality strategies and there are few direct measurements of their gaseous abundance in the atmosphere. This study describes the chemically comprehensive and continuous measurements of organic compounds in a developed megacity (London, which demonstrate that on a seasonal median basis, diesel-related hydrocarbons represent only 20–30 % of the total hydrocarbon mixing ratio but comprise more than 50 % of the atmospheric hydrocarbon mass and are a dominant local source of secondary organic aerosols. This study shows for the first time that 60 % of the winter primary hydrocarbon hydroxyl radical reactivity is from diesel-related hydrocarbons and using the maximum incremental reactivity scale, we predict that they contribute up to 50 % of the ozone production potential in London. Comparing real-world urban composition with regulatory emissions inventories in the UK and US highlights a previously unaccounted for, but very significant, under-reporting of diesel-related hydrocarbons; an underestimation of a factor ~4 for C9 species rising to a factor of over 70 for C12 during winter. These observations show that hydrocarbons from diesel vehicles can dominate gas phase reactive carbon in cities with high diesel fleet fractions. Future control of urban particulate matter and ozone in such locations requires a shift in policy focus onto gas phase hydrocarbons released from diesels as this vehicle type continues to displace gasoline world-wide.

Particulate matter and polycyclic aromatic hydrocarbons in a selected athletic hall: ambient concentrations, origin and effects on human health

Science.gov (United States)

Kuskowska, Karolina; Rogula-Kozłowska, Wioletta; Rogula-Kopiec, Patrycja

2018-01-01

The paper presents the results of research on the concentration of 16 polycyclic aromatic hydrocarbons (PAHs) associated with total suspended particles (TSP) and their respirable fraction (PM4) in one of the Warsaw sports halls. Samples of dust were collected for 15 days simultaneously inside and outside (atmospheric air) of the sports hall. The obtained data allowed calculating diagnostic ratios indicating the origin of the PAHs and selected indicators of cumulative exposure to the PAH mixture. Both PM and PAH in the surveyed area were derived from the combustion of solid fuels; this involved pollution both in the atmospheric air and in the air inside the sports hall. It has been shown that the exposure of sports hall users to PAHs is significantly higher than the exposure resulting from concentrations recorded in the atmospheric air.

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.

Development of a Raman spectroscopy technique to detect alternate transportation fuel hydrocarbon intermediates in complex combustion environments.

Energy Technology Data Exchange (ETDEWEB)

Ekoto, Isaac W.; Barlow, Robert S.

2012-12-01

Spontaneous Raman spectra for important hydrocarbon fuels and combustion intermediates were recorded over a range of low-to-moderate flame temperatures using the multiscalar measurement facility located at Sandia/CA. Recorded spectra were extrapolated to higher flame temperatures and then converted into empirical spectral libraries that can readily be incorporated into existing post-processing analysis models that account for crosstalk from overlapping hydrocarbon channel signal. Performance testing of the developed libraries and reduction methods was conducted through an examination of results from well-characterized laminar reference flames, and was found to provide good agreement. The diagnostic development allows for temporally and spatially resolved flame measurements of speciated hydrocarbon concentrations whose parent is more chemically complex than methane. Such data are needed to validate increasingly complex flame simulations.

Subsurface biogenic gas rations associated with hydrocarbon contamination

International Nuclear Information System (INIS)

Marrin, D.L.

1991-01-01

Monitoring the in situ bioreclamation of organic chemicals in soil is usually accomplished by collecting samples from selected points during the remediation process. This technique requires the installation and sampling of soil borings and does not allow for continuous monitoring. The analysis of soil vapor overlying hydrocarbon-contaminated soil and groundwater has been used to detect the presence of nonaqueous phase liquids (NAPL) and to locate low-volatility hydrocarbons that are not directly detected by more conventional soil gas methods. Such soil vapor sampling methods are adaptable to monitoring the in situ bioremediation of soil and groundwater contamination. This paper focuses on the use of biogenic gas ratio in detecting the presence of crude oil and gasoline in the subsurface

Aliphatic and polycyclic aromatic hydrocarbons characterisation of Coimbra and Oporto PM2.5 urban aerosol

Science.gov (United States)

Rocha, A. C.; Mirante, F.; Gonçalves, C.; Nunes, T.; Alves, C.; Evtyugina, M.; Kowacz, M.; Pio, C.; Rocha, C.; Vasconcelos, T.

2009-04-01

The concentration of organic pollutants in urban areas is mostly due to incomplete combustion from vehicles, industries and domestic heating. Some of these compounds, principally the aliphatic (ALIPH) and polycyclic aromatic hydrocarbons (PAHs) promote harmful effects in human health. The determination of the ALIPH and PAHs concentration levels and their possible emission sources are useful for air quality management and source apportionment studies. In order to estimate and compare the ambient concentrations and establish the main sources of these compounds, the fine fraction of the atmospheric particulate matter (PM2.5) was collected simultaneously in Oporto and Coimbra during summer and winter seasons using a high volume sampler. The organic compounds were extracted from the particulate matter, under reflux with dichloromethane and the total organic extract (TOE) was fractionated by flash chromatography using five different eluents with increasing polarity. The hydrocarbon fractions were analysed by gas chromatography/mass spectrometry (GC/MS). Here we present and discuss the qualitative and quantitative composition of the aliphatic and aromatic fractions present in PM2.5 samples from both cities. The homologous series of C14 to C34 n-alkanes, isoprenoid hydrocarbons (pristane and phytane), PAHs and some petroleum markers have been identified and quantified. With the purpose of identifying the possible sources, various molecular diagnostic ratios were calculated. The global carbon preference index (CPI) closer to the unity, the large concentration of the unresolved complex mixture (UCM) and the presence of PAHs indicate that motor vehicle exhaust was the main emission source of the aliphatic and polycyclic aromatic fractions of Oporto and Coimbra aerosol, especially in the first city. Also, the remarkable presence of petroleum biomarkers such, as hopanes, confirms the previous results. Concentration ratios between PAHs were calculated and used to assign emission

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

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.

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.

Effects of blend ratio between high density polyethylene and biomass on co-gasification behavior in a two-stage gasification system

KAUST Repository

Park, Jae Hyun

2016-08-12

The co-gasification of a high density polyethylene (HDPE) blended with a biomass has been carried out in a two-stage gasification system which comprises an oxidative pyrolysis reactor and a thermal plasma reactor. The equivalence ratio was changed from 0.38 to 0.85 according to the variation of blend ratio between HDPE and biomass. The highest production yield was achieved to be 71.4 mol/h, when the equivalence ratio was 0.47. A large amount of hydrocarbons was produced from the oxidative pyrolysis reactor as decreasing equivalence ratio below 0.41, while the CO2 concentration significantly increased with a high equivalence ratio over 0.65. The production yield was improved by the thermal plasma reactor due to the conversion of hydrocarbons into syngas in a high temperature region of thermal plasma. At the equivalence ratio of 0.47, conversion selectivities of CO and H2 from hydrocarbons were calculated to be 74% and 44%, respectively. © 2016 Hydrogen Energy Publications LLC.

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

Diagnostic performance of instantaneous wave-free ratio for the evaluation of coronary stenosis severity confirmed by fractional flow reserve: A PRISMA-compliant meta-analysis of randomized studies.

Science.gov (United States)

Man, Wanrong; Hu, Jianqiang; Zhao, Zhijing; Zhang, Mingming; Wang, Tingting; Lin, Jie; Duan, Yu; Wang, Ling; Wang, Haichang; Sun, Dongdong; Li, Yan

2016-09-01

The instantaneous wave-free ratio (iFR) is a new vasodilator-free index of coronary stenosis severity. The aim of this meta-analysis is to assess the diagnostic performance of iFR for the evaluation of coronary stenosis severity with fractional flow reserve as standard reference. We searched PubMed, EMBASE, CENTRAL, ProQuest, Web of Science, and International Clinical Trials Registry Platform (ICTRP) for publications concerning the diagnostic value of iFR. We used a random-effects covariate to synthesize the available data of sensitivity, specificity, positive likelihood ratio (LR+), negative likelihood ratio (LR-), and diagnostic odds ratio (DOR). Overall test performance was summarized by the summary receiver operating characteristic curve (sROC) and the area under the curve (AUC). Eight studies with 1611 subjects were included in the meta-analysis. The pooled sensitivity, specificity, LR+, LR-, and DOR for iFR were respectively 73.3% (70.1-76.2%), 86.4% (84.3-88.3%), 5.71 (4.43-7.37), 0.29 (0.22-0.38), and 20.54 (16.11-26.20). The area under the summary receiver operating characteristic curves for iFR was 0.8786. No publication bias was identified. The available evidence suggests that iFR may be a new, simple, and promising technology for coronary stenosis physiological assessment.

SDSS-IV MaNGA: the impact of diffuse ionized gas on emission-line ratios, interpretation of diagnostic diagrams and gas metallicity measurements

Science.gov (United States)

Zhang, Kai; Yan, Renbin; Bundy, Kevin; Bershady, Matthew; Haffner, L. Matthew; Walterbos, René; Maiolino, Roberto; Tremonti, Christy; Thomas, Daniel; Drory, Niv; Jones, Amy; Belfiore, Francesco; Sánchez, Sebastian F.; Diamond-Stanic, Aleksandar M.; Bizyaev, Dmitry; Nitschelm, Christian; Andrews, Brett; Brinkmann, Jon; Brownstein, Joel R.; Cheung, Edmond; Li, Cheng; Law, David R.; Roman Lopes, Alexandre; Oravetz, Daniel; Pan, Kaike; Storchi Bergmann, Thaisa; Simmons, Audrey

2017-04-01

Diffuse ionized gas (DIG) is prevalent in star-forming galaxies. Using a sample of 365 nearly face-on star-forming galaxies observed by Mapping Nearby Galaxies at APO, we demonstrate how DIG in star-forming galaxies impacts the measurements of emission-line ratios, hence the interpretation of diagnostic diagrams and gas-phase metallicity measurements. At fixed metallicity, DIG-dominated low ΣHα regions display enhanced [S II]/Hα, [N II]/Hα, [O II]/Hβ and [O I]/Hα. The gradients in these line ratios are determined by metallicity gradients and ΣHα. In line ratio diagnostic diagrams, contamination by DIG moves H II regions towards composite or low-ionization nuclear emission-line region (LI(N)ER)-like regions. A harder ionizing spectrum is needed to explain DIG line ratios. Leaky H II region models can only shift line ratios slightly relative to H II region models, and thus fail to explain the composite/LI(N)ER line ratios displayed by DIG. Our result favours ionization by evolved stars as a major ionization source for DIG with LI(N)ER-like emission. DIG can significantly bias the measurement of gas metallicity and metallicity gradients derived using strong-line methods. Metallicities derived using N2O2 are optimal because they exhibit the smallest bias and error. Using O3N2, R23, N2 = [N II]/Hα and N2S2Hα to derive metallicities introduces bias in the derived metallicity gradients as large as the gradient itself. The strong-line method of Blanc et al. (IZI hereafter) cannot be applied to DIG to get an accurate metallicity because it currently contains only H II region models that fail to describe the DIG.

Remediation of total petroleum hydrocarbons using combined in-vessel composting ‎and oxidation by activated persulfate

Directory of Open Access Journals (Sweden)

A.R. Asgari

2017-12-01

Full Text Available This study was investigated the efficiency of activated persulfate and ‎in-vessel composting for removal of total petroleum hydrocarbons. ‎Remediation by activated persulfate with ferrous sulfate as pre-treatment was done at batch system. In the chemical oxidation, various variables including persulfate concentrations (10-3000 mg/g as waste, pH (3-7, ferrous sulfate (0.5-4 mg/g as wasteand temperature (20-60°C were studied. In the biological system, premature compost was added as an amendment. The filter cake to compost ratio were 1:0 (as control and 1:5 to 15 (as dry basis. C: N: P ratio and moisture content were 100:5:1 and 45-60%, respectively. The results showed that acidic pH (pH=3 had high efficiency for the removal of total petroleum hydrocarbons by activated persulfate. Temperature had the significant effect during the persulfate oxidation. When ferrous sulfate was used as an activator for degradation at acidic condition and 60°C, removal efficiency increased to 47.32%. The results of biological process showed that the minimum total petroleum hydrocarbons removal in all reactors was 62 percent. The maximum and minimum removal efficiency was obtained at 1:5 (69.46% and 1:10 (62.42% mixing ratios, respectively. Kinetic study showed that second order kinetic model (R2>0.81 shows the best agreement with the experimental data and the rate of TPH degradation at low mixing ratio (1:3 was faster than high mixing ratio (1:15. Therefore, according to the results, in-vessel composting after pre-treatment by activated persulfate is suggested as an efficient process for degradation of total petroleum hydrocarbons.

Phytoremediation of hydrocarbon-contaminated soil using plants adapted to western Canadian climate

International Nuclear Information System (INIS)

Robson, D.B.

2003-01-01

Phytoremediation relies on the use of plants for in-situ treatment of hydrocarbon contaminated soils. It is based on relationships between plants, microorganisms and the environment. The advantages of the process are its low cost and minimal soil disturbance. Phytoremediation has not been widely implemented in Canada because only a few native or non-native plant species have been tested for hydrocarbon tolerance or degradation ability. More studies are needed to fully understand why some plants are more tolerant of hydrocarbons than others, and whether tolerant species increase hydrocarbon degradation. In this study, several field and growth chamber experiments were conducted to examine hydrocarbon tolerance in plants. Hydrocarbon contaminated field plots had higher soil pH, carbon to nitrogen ratio and bare ground, lower total nitrogen, available phosphorous and litter cover. The mean diversity at the uncontaminated sites was 0.52. It was 0.45 at the contaminated sites. Mean species similarity between contaminated and uncontaminated sites was 31.1 per cent and cover similarity was 22.2 per cent. The common plants in the contaminated field included kochia, wild barley, salt grass, bluegrass, and wheatgrass. The plants that formed most plant cover on contaminated plots were non-mycorrhizal, self-pollinating, and large seeded. The species with the highest survival after 5 weeks in hydrocarbon contaminated soils included one native and 4 non-native grasses, 2 native and 3 non-native legumes and 2 native forbs. All plants (with the exception of Indian breadroot) grown in hydrocarbon contaminated potting soil had lower total biomass and lower growth rates compared to the control

Phytoremediation of hydrocarbon-contaminated soil using plants adapted to western Canadian climate

Energy Technology Data Exchange (ETDEWEB)

Robson, D.B.

2003-07-01

Phytoremediation relies on the use of plants for in-situ treatment of hydrocarbon contaminated soils. It is based on relationships between plants, microorganisms and the environment. The advantages of the process are its low cost and minimal soil disturbance. Phytoremediation has not been widely implemented in Canada because only a few native or non-native plant species have been tested for hydrocarbon tolerance or degradation ability. More studies are needed to fully understand why some plants are more tolerant of hydrocarbons than others, and whether tolerant species increase hydrocarbon degradation. In this study, several field and growth chamber experiments were conducted to examine hydrocarbon tolerance in plants. Hydrocarbon contaminated field plots had higher soil pH, carbon to nitrogen ratio and bare ground, lower total nitrogen, available phosphorous and litter cover. The mean diversity at the uncontaminated sites was 0.52. It was 0.45 at the contaminated sites. Mean species similarity between contaminated and uncontaminated sites was 31.1 per cent and cover similarity was 22.2 per cent. The common plants in the contaminated field included kochia, wild barley, salt grass, bluegrass, and wheatgrass. The plants that formed most plant cover on contaminated plots were non-mycorrhizal, self-pollinating, and large seeded. The species with the highest survival after 5 weeks in hydrocarbon contaminated soils included one native and 4 non-native grasses, 2 native and 3 non-native legumes and 2 native forbs. All plants (with the exception of Indian breadroot) grown in hydrocarbon contaminated potting soil had lower total biomass and lower growth rates compared to the control.

Hydrocarbons on Phoebe, Iapetus, and Hyperion: Quantitative Analysis

Science.gov (United States)

Cruikshank, Dale P.; MoreauDalleOre, Cristina; Pendleton, Yvonne J.; Clark, Roger Nelson

2012-01-01

We present a quantitative analysis of the hydrocarbon spectral bands measured on three of Saturn's satellites, Phoebe, Iaperus, and Hyperion. These bands, measured with the Cassini Visible-Infrared Mapping Spectrometer on close fly-by's of these satellites, are the C-H stretching modes of aromatic hydrocarbons at approximately 3.28 micrometers (approximately 3050 per centimeter), and the are four blended bands of aliphatic -CH2- and -CH3 in the range approximately 3.36-3.52 micrometers (approximately 2980- 2840 per centimeter) bably indicating the presence of polycyclic aromatic hydrocarbons (PAH), is unusually strong in comparison to the aliphatic bands, resulting in a unique signarure among Solar System bodies measured so far, and as such offers a means of comparison among the three satellites. The ratio of the C-H bands in aromatic molecules to those in aliphatic molecules in the surface materials of Phoebe, NAro:NAliph approximately 24; for Hyperion the value is approximately 12, while laperus shows an intermediate value. In view of the trend of the evolution (dehydrogenation by heat and radiation) of aliphatic complexes toward more compact molecules and eventually to aromatics, the relative abundances of aliphatic -CH2- and -CH3- is an indication of the lengths of the molecular chain structures, hence the degree of modification of the original material. We derive CH2:CH3 approximately 2.2 in the spectrum of low-albedo material on laperus; this value is the same within measurement errors to the ratio in the diffuse interstellar medium. The similarity in the spectral signatures of the three satellites, plus the apparent weak trend of aromatic/aliphatic abundance from Phoebe to Hyperion, is consistent with, and effectively confirms that the source of the hydrocarbon-bearing material is Phoebe, and that the appearance of that material on the other two satellites arises from the deposition of the inward-spiraling dust that populates the Phoebe ring.

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.

Long term trends in atmospheric concentrations of polycyclic aromatic hydrocarbons and nitropolycyclic aromatic hydrocarbons: A study of Japanese cities from 1997 to 2014.

Science.gov (United States)

Hayakawa, Kazuichi; Tang, Ning; Nagato, Edward Gou; Toriba, Akira; Sakai, Shigekatsu; Kano, Fumio; Goto, Sumio; Endo, Osamu; Arashidani, Kei-Ichi; Kakimoto, Hitoshi

2018-02-01

Total suspended particulate matter (TSP) was collected during the summer and winter in five Japanese cities spanning Hokkaido to Kyushu (Sapporo, Kanazawa, Tokyo, Sagamihara and Kitakyushu) from 1997 to 2014. Nine polycyclic aromatic hydrocarbons (PAHs) with four to six rings, including pyrene (Pyr) and benzo[a]pyrene (BaP), were identified using high-performance liquid chromatography (HPLC) with fluorescence detection. Two nitropolycyclic aromatic hydrocarbons (NPAHs), 1-nitropyrene (1-NP) and 6-nitrobenzo[a]pyrene (6-NBaP), were identified by HPLC with chemiluminescence detection. A comparison of PAH and NPAH concentrations and [NPAH]/[PAH] ratios such as [1-NP]/[Pyr] and [6-NBaP]/[BaP] revealed the following characteristics in the five cities: (1) In Sapporo, Kanazawa, Tokyo and Sagamihara, the concentrations of PAHs and NPAHs were high at the beginning of the sampling period and then steadily decreased, with NPAHs decreasing faster than PAHs. The large initial [1-NP]/[Pyr] ratios suggest that the major contributor was automobiles but subsequent decreases in this ratio suggest decreased automobile contributions. (2) By contrast, PAH concentrations in Kitakyushu did not decrease during the sampling period, though concentrations of NPAHs decreased. The consistently smaller [1-NP]/[Pyr] ratio and larger [6-NBaP]/[BaP] ratio in Kitakyushu suggests that the major contributor of PAHs was not automobiles but iron manufacturing which uses a large amount of coal. The sudden increase in atmospheric PAH concentrations in the winter of 2014 may also be due to iron manufacturing. Copyright © 2017 Elsevier Ltd. All rights reserved.

Particulate matter and polycyclic aromatic hydrocarbons in a selected athletic hall: ambient concentrations, origin and effects on human health

Directory of Open Access Journals (Sweden)

Kuskowska Karolina

2018-01-01

Full Text Available The paper presents the results of research on the concentration of 16 polycyclic aromatic hydrocarbons (PAHs associated with total suspended particles (TSP and their respirable fraction (PM4 in one of the Warsaw sports halls. Samples of dust were collected for 15 days simultaneously inside and outside (atmospheric air of the sports hall. The obtained data allowed calculating diagnostic ratios indicating the origin of the PAHs and selected indicators of cumulative exposure to the PAH mixture. Both PM and PAH in the surveyed area were derived from the combustion of solid fuels; this involved pollution both in the atmospheric air and in the air inside the sports hall. It has been shown that the exposure of sports hall users to PAHs is significantly higher than the exposure resulting from concentrations recorded in the atmospheric air.

D/H ratio for Jupiter

International Nuclear Information System (INIS)

Smith, H.; Schempp, W.V.; Baines, K.H.

1989-01-01

Observations of Jupiter's spectrum near the R5(0) HD line at 6063.88 A are reported. A feature with an equivalent width of 0.065 + or - 0.021 mA is coincident with the expected line. This feature is compared with HD profiles computed for inhomogeneous scattering models for Jupiter to yield a range for the Jovian D/H ratio of 1.0-2.9 x 10 to the -5th. This D/H ratio is in the lower range of previously reported D/H values for Jupiter and corresponds to an essentially solar D/H ratio for Jupiter. The detection of HD features in the presence of probable blends with spectral features of minor atmospheric hydrocarbon molecules is discussed. Such blends may make unambiguous identification of HD features difficult. 26 references

Effects of P/Ni ratio and Ni content on performance of γ-Al_2O_3-supported nickel phosphides for deoxygenation of methyl laurate to hydrocarbons

International Nuclear Information System (INIS)

Zhang, Zhena; Tang, Mingxiao; Chen, Jixiang

2016-01-01

Graphical abstract: - Highlights: • The formation of AlPO_4 was unfavorable for that of nickel phosphides. • The phase compositions of nickel phosphide depended on the amount of reduced P. • Catalytic activity was determined by surface Ni site density and catalyst acidity. • HDO pathway was promoted by increasing P/Ni ratio and Ni content. • Nickel phosphide gave much higher carbon yield and lower H_2 consumption than Ni. - Abstract: γ-Al_2O_3-supported nickel phosphides (mNi-Pn) were prepared by the TPR method and tested for the deoxygenation of methyl laurate to hydrocarbons. The effects of the P/Ni ratio (n = 1.0–2.5) and Ni content (m = 5–15 wt.%) in the precursors on their structure and performance were investigated. Ni/γ-Al_2O_3 was also studied for comparison. It was found that the formation of AlPO_4 in the precursor inhibited the reduction of phosphate and so the formation of nickel phosphides. With increasing the P/Ni ratio and Ni content, the Ni, Ni_3P, Ni_1_2P_5 and Ni_2P phases orderly formed, accompanying with the increases of their particle size and the amount of weak acid sites (mainly due to P-OH group), while the CO uptake and the amount of medium strong acid sites (mainly related to Ni sites) reached maximum on 10%Ni-P1.5. In the deoxygenation reaction, compared with Ni/γ-Al_2O_3, the mNi-Pn catalysts showed much lower activities for decarbonylation, C−C hydrogenolysis and methanation due to the ligand and ensemble effects of P. The conversion and the selectivity to n-C11 and n-C12 hydrocarbons achieved maximum on 10%Ni-P 2.0 for the 10%Ni-Pn catalysts and on 8%Ni-P2.0 for the mNi-P2.0 catalysts, while the turnover frequency (TOF) of methyl laurate mainly increased with the P/Ni ratio and Ni content. We propose that TOF was influenced by the nickel phosphide phases, the catalyst acidity and the particle size as well as the synergetic effect between the Ni site and acid site. Again, the hydrodeoxygenation pathway of methyl

Oil-shale gasification for obtaining of gas for synthesis of aliphatic hydrocarbons

Energy Technology Data Exchange (ETDEWEB)

Strizhakova, Yu. [Samara State Univ. (Russian Federation); Avakyan, T.; Lapidus, A.L. [I.M. Gubkin Russian State Univ. of Oil and Gas, Moscow (Russian Federation)

2011-07-01

Nowadays, the problem of qualified usage of solid fossil fuels as raw materials for obtaining of motor fuels and chemical products is becoming increasingly important. Gasification with further processing of gaseous products is a one of possible ways of their use. Production of synthesis gas with H{sub 2}/CO ratio equal 2 is possible by gasification of oil-shale. This gas is converted into the mixture of hydrocarbons over cobalt catalyst at temperature from 160 to 210 C at atmospheric pressure. The hydrocarbons can be used as motor, including diesel, or reactive fuel. (orig.)

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.

Diagnostic Development on NSTX

International Nuclear Information System (INIS)

A.L. Roquemore; D. Johnson; R. Kaita; et al

1999-01-01

Diagnostics are described which are currently installed or under active development for the newly commissioned NSTX device. The low aspect ratio (R/a less than or equal to 1.3) and low toroidal field (0.1-0.3T) used in this device dictate adaptations in many standard diagnostic techniques. Technical summaries of each diagnostic are given, and adaptations, where significant, are highlighted

A mid-infrared absorption diagnostic for acetylene detection

KAUST Repository

KC, Utsav

2015-05-14

Acetylene is an important combustion intermediate and plays a critical role in soot formation. Accurate measurements of trace concentrations of acetylene can be very useful in validating hydrocarbon oxidation and soot formation mechanisms. Strongest vibrational band of acetylene near 13.7 μm is probed here to develop a highly sensitive absorption diagnostic. Experiments are carried out behind reflected shock waves to measure absorption cross sections of acetylene near 730 cm−1 over a wide range of temperatures (1000–2200 K) and pressures (1–5 bar). The diagnostic is demonstrated by measuring acetylene formation during the shock-heated pyrolysis and oxidation of propene. © 2015 Springer-Verlag Berlin Heidelberg

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.

Gamma ray spectrometry logs as a hydrocarbon indicator for clastic reservoir rocks in Egypt

International Nuclear Information System (INIS)

Al-Alfy, I.M.; Nabih, M.A.; Eysa, E.A.

2013-01-01

Petroleum oil is an important source for the energy in the world. The Gulf of Suez, Nile Delta and South Valley are important regions for studying hydrocarbon potential in Egypt. A thorium normalization technique was applied on the sandstone reservoirs in the three regions to determine the hydrocarbon potentialities zones using the three spectrometric radioactive gamma ray-logs (eU, eTh and K% logs). The conventional well logs (gamma-ray, deep resistivity, shallow resistivity, neutron, density and sonic logs) are analyzed to determine the net pay zones in these wells. Indices derived from thorium normalized spectral logs indicate the hydrocarbon zones in petroleum reservoirs. The results of this technique in the three regions (Gulf of Suez, Nile Delta and South Valley) are in agreement with the results of the conventional well log analyses by ratios of 82%, 78% and 71% respectively. - Highlights: ► The positive DRAD values indicate the hydrocarbon zones in petroleum reservoirs. ► Thorium normalization was applied to determine the hydrocarbon potentialities. ► The conventional well logs are analyzed to determine the net pay zones in wells. ► Determining hydrocarbon potentialities zones using spectrometric gamma-ray logs

Molecular Tracers of Saturated and Polycyclic Aromatic Hydrocarbon Inputs into Central Park Lake, New York City

Science.gov (United States)

YAN, BEIZHAN; ABRAJANO, TEOFILO A.; BOPP, RICHARD F.; CHAKY, DAMON A.; BENEDICT, LUCILLE A.; CHILLRUD, STEVEN N.

2011-01-01

Saturated hydrocarbons (SH) and polycyclic aromatic hydrocarbons (PAHs) have been quantified in a sediment core obtained from Central Park Lake, New York City. Radionuclides 210Pb and 137Cs were used to assign approximate dates to each individual section in the core. The dating profile based on 210Pb matches very well with the time constraints provided by 137Cs. Radionuclide-derived depositional dates are consistent with temporal information from the petroleum-indicator ratio U/R [the ratio of unresolved complex mixture (UCM) to saturated hydrocarbons in the aliphatic fraction] and the history of fuel use in the NYC area. Ratios of 1,7-dimethylphenanthrane (DMP) to 1,7-DMP plus 2,6-DMP [1,7/(1,7 + 2,6)-DMP], retene to retene plus chrysene [Ret/(Ret + Chy)], and fluoranthene to fluoranthene plus pyrene [Fl/(Fl + Py)] provide additional source discrimination throughout the core. Results show that the ratio U/R is sensitive to petroleum inputs and Ret/(Ret + Chy) is responsive to contributions from softwood combustion, whereas both Fl/(Fl + Py) and 1,7/(1,7 + 2,6)-DMP can be used to discriminate among wood, coal, and petroleum combustion sources. Combined use of these ratios suggests that in New York City, wood combustion dominated 100 years ago, with a shift to coal combustion occurring from the 1900s to the 1950s. Petroleum use began around the 1920s and has dominated since the 1940s. PMID:16201624

Determination and Distribution of Polycyclic Aromatic Hydrocarbons in Rivers, Sediments and Wastewater Effluents in Vhembe District, South Africa

Directory of Open Access Journals (Sweden)

Joshua N. Edokpayi

2016-03-01

Full Text Available Polycyclic aromatic hydrocarbons are very toxic and persistent environmental contaminants. This study was undertaken to assess the concentrations and possible sources of 16 PAHs (Polycyclic aromatic hydrocarbons classified by the United State Environmental Protection Agency as priority pollutants in water and sediments of the Mvudi and Nzhelele Rivers. Effluents from Thohoyandou wastewater treatment plant and Siloam waste stabilization ponds were also investigated. Diagnostic ratios were used to evaluate the possible sources of PAHs. PAHs in the water samples were extracted using 1:1 dichloromethane and n-hexane mixtures, while those in the sediment samples were extracted with 1:1 acetone and dichloromethane using an ultrasonication method. The extracts were purified using an SPE technique and reconstituted in n-hexane before analyses with a gas chromatograph time of flight—mass spectrometer. The results obtained indicate the prevalence of high molecular weight PAHs in all the samples. PAHs concentrations in water and sediment samples from all the sampling sites were in the range of 13.174–26.382 mg/L and 27.10–55.93 mg/kg, respectively. Combustion of biomass was identified as the major possible source of PAHs. Effluents from wastewater treatment facilities were also considered as major anthropogenic contributions to the levels of PAHs found in both river water and sediments. Mvudi and Nzhelele Rivers show moderate to high contamination level of PAHs.

Chemical characterization and spatial distribution of PAHs and heavy hydrocarbons in rural sites of Campania Region, South Italy.

Science.gov (United States)

Monaco, D; Riccio, A; Chianese, E; Adamo, P; Di Rosa, S; Fagnano, M

2015-10-01

In this paper, the behaviour and distribution patterns of heavy hydrocarbons and several polycyclic aromatic hydrocarbon (PAH) priority pollutants, as listed by the US Environmental Protection Agency, were evaluated in 891 soil samples. The samples were collected in three expected polluted rural sites in Campania (southern Italy) as part of the LIFE11 ECOREMED project, funded by the European Commission, to test innovative agriculture-based soil restoration techniques. These sites have been selected because they have been used for the temporary storage of urban and building waste (Teverola), subject to illicit dumping of unknown material (Trentola-Ducenta), or suspected to be polluted by metals due to agricultural practices (Giugliano). Chemical analysis of soil samples allowed the baseline pollution levels to be determined prior to any intervention. It was found that these areas can be considered contaminated for residential use, in accordance with Italian environmental law (Law Decree 152/2006). Statistical analysis applied to the data proved that average mean concentrations of heavy hydrocarbons could be as high as 140 mg/kg of dry soil with peaks of 700 mg/kg of dry soil, for the Trentola-Ducenta site; the median concentration of analytical results for hydrocarbon (HC) concentration for the Trentola-Ducenta and Giugliano sites was 63 and 73.4 mg/kg dry soil, respectively; for Teverola, the median level was 35 mg/kg dry soil. Some PAHs (usually benzo(a)pyrene) also exceeded the maximum allowed level in all sites. From the principal component analysis applied to PAH concentrations, it emerged that pollutants can be supposed to derive from a single source for the three sites. Diagnostic ratios calculated to determine possible PAH sources suggest petroleum combustion or disposal practice. Our sampling protocol also showed large dishomogeneity in soil pollutant spatial distribution, even at a scale as small as 3.3 m, indicating that variability could emerge at very

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.

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.

Hyperfine Induced Transitions as Diagnostics of Low Density Plasmas and Isotopic Abundance ratios.

Science.gov (United States)

Brage, T.; Judge, P. G.; Aboussaid, A.; Godefroid, M. R.; Jonsson, P.; Leckrone, D. S.

1996-05-01

We propose a new diagnostics of isotope abundance ratios and electron densities for low density plasmas, in the form of J = 0 -> J(') = 0 radiative transitions. These are usually viewed as being allowed only through two-photon decay, but they may also be induced by the hyperfine (HPF) interaction in atomic ions. This predicts a companion line to the E1] and M2 lines in the UV0.01 multiplet of ions isoelectronic to beryllium (e.g. C III, N IV, O V and Fe XXII) or magnesium (e.g. Si II, Ca IX, Fe XV and Ni XVII). As an example the companion line to the well known lambda lambda 1906.7,1908.7 lines in C III will be at 1909.597 Angstroms, but only present in the (13) C isotope (which has nuclear spin different from zero). We present new and accurate decay rates for the nsnp (3P^oJ) -> ns(2) (1S_{J('}=0)) transitions in ions of the Be (n=2) and Mg (n=3) isoelectronic sequences. We show that the HPF induced decay rates for the J = 0 -> J(') = 0 transitions are many orders of magnitude larger than those for the competing two-photon processes and, when present, are typically one or two orders of magnitude smaller than the decay rates of the magnetic quadrupole ( J = 2-> J(') = 0) transitions for these ions. We show that several of these HPF-induced transitions are of potential astrophysical interest, in ions of C, N, Na, Mg, Al, Si, K, Cr, Fe and Ni. We highlight those cases that may be of particular diagnostic value for determining isotopic abundance ratios and/or electron densities from UV or EUV emission line data. We present our atomic data in the form of scaling laws so that, given the isotopic nuclear spin and magnetic moment, a simple expression yields estimates for HPF induced decay rates. We examine some UV solar and nebular data in the light of these new results and suggest possible cases for future study. We could not find evidence for the existence of HPF induced lines in the spectra we examined, but we demonstrate that existing data have come close to providing

Concentrations and sources of polycyclic aromatic hydrocarbons in surface coastal sediments of the northern Gulf of Mexico

Science.gov (United States)

2014-01-01

Background Coastal sediments in the northern Gulf of Mexico have a high potential of being contaminated by petroleum hydrocarbons, such as polycyclic aromatic hydrocarbons (PAHs), due to extensive petroleum exploration and transportation activities. In this study we evaluated the spatial distribution and contamination sources of PAHs, as well as the bioavailable fraction in the bulk PAH pool, in surface marsh and shelf sediments (top 5 cm) of the northern Gulf of Mexico. Results PAH concentrations in this region ranged from 100 to 856 ng g−1, with the highest concentrations in Mississippi River mouth sediments followed by marsh sediments and then the lowest concentrations in shelf sediments. The PAH concentrations correlated positively with atomic C/N ratios of sedimentary organic matter (OM), suggesting that terrestrial OM preferentially sorbs PAHs relative to marine OM. PAHs with 2 rings were more abundant than those with 5–6 rings in continental shelf sediments, while the opposite was found in marsh sediments. This distribution pattern suggests different contamination sources between shelf and marsh sediments. Based on diagnostic ratios of PAH isomers and principal component analysis, shelf sediment PAHs were petrogenic and those from marsh sediments were pyrogenic. The proportions of bioavailable PAHs in total PAHs were low, ranging from 0.02% to 0.06%, with higher fractions found in marsh than shelf sediments. Conclusion PAH distribution and composition differences between marsh and shelf sediments were influenced by grain size, contamination sources, and the types of organic matter associated with PAHs. Concentrations of PAHs in the study area were below effects low-range, suggesting a low risk to organisms and limited transfer of PAHs into food web. From the source analysis, PAHs in shelf sediments mainly originated from direct petroleum contamination, while those in marsh sediments were from combustion of fossil fuels. PMID:24641695

Polycyclic Aromatic Hydrocarbons Bound to PM 2.5 in Urban Coimbatore, India with Emphasis on Source Apportionment

Directory of Open Access Journals (Sweden)

R. Mohanraj

2012-01-01

Full Text Available Coimbatore is one of the fast growing industrial cities of Southern India with an urban population of 1.9 million. This study attempts to evaluate the trends of airborne fine particulates (PM 2.5 and polyaromatic hydrocarbons (PAH on them. The PM 2.5 mass was collected in polytetra fluoroethylene filters using fine particulate sampler at monthly intervals during March 2009 to February 2010. PAHs were extracted from PM 2.5 and estimated by high-performance liquid chromatography. It is alarming to note that PM 2.5 values ranged between 27.85 and 165.75 μg/m3 and exceeded the air quality standards in many sampling events. The sum of 9 PAHs bound to PM 2.5 in a single sampling event ranged from 4.1 to 1632.3 ng/m3. PAH diagnostic ratios and principal component analysis results revealed vehicular emissions and diesel-powered generators as predominant sources of PAH in Coimbatore.

Hydrocarbons on Saturn's satellites Iapetus and Phoebe

Science.gov (United States)

Cruikshank, D.P.; Wegryn, E.; Dalle, Ore C.M.; Brown, R.H.; Bibring, J.-P.; Buratti, B.J.; Clark, R.N.; McCord, T.B.; Nicholson, P.D.; Pendleton, Y.J.; Owen, T.C.; Filacchione, G.; Coradini, A.; Cerroni, P.; Capaccioni, F.; Jaumann, R.; Nelson, R.M.; Baines, K.H.; Sotin, Christophe; Bellucci, G.; Combes, M.; Langevin, Y.; Sicardy, B.; Matson, D.L.; Formisano, V.; Drossart, P.; Mennella, V.

2008-01-01

Material of low geometric albedo (pV ??? 0.1) is found on many objects in the outer Solar System, but its distribution in the saturnian satellite system is of special interest because of its juxtaposition with high-albedo ice. In the absence of clear, diagnostic spectral features, the composition of this low-albedo (or "dark") material is generally inferred to be carbon-rich, but the form(s) of the carbon is unknown. Near-infrared spectra of the low-albedo hemisphere of Saturn's satellite Iapetus were obtained with the Visible-Infrared Mapping Spectrometer (VIMS) on the Cassini spacecraft at the fly-by of that satellite of 31 December 2004, yielding a maximum spatial resolution on the satellite's surface of ???65 km. The spectral region 3-3.6 ??m reveals a broad absorption band, centered at 3.29 ??m, and concentrated in a region comprising about 15% of the low-albedo surface area. This is identified as the C{single bond}H stretching mode vibration in polycyclic aromatic hydrocarbon (PAH) molecules. Two weaker bands attributed to {single bond}CH2{single bond} stretching modes in aliphatic hydrocarbons are found in association with the aromatic band. The bands most likely arise from aromatic and aliphatic units in complex macromolecular carbonaceous material with a kerogen- or coal-like structure, similar to that in carbonaceous meteorites. VIMS spectra of Phoebe, encountered by Cassini on 11 June 2004, also show the aromatic hydrocarbon band, although somewhat weaker than on Iapetus. The origin of the PAH molecular material on these two satellites is unknown, but PAHs are found in carbonaceous meteorites, cometary dust particles, circumstellar dust, and interstellar dust. ?? 2007 Elsevier Inc. All rights reserved.

Effects of hydrocarbon contamination on ozone generation with dielectric barrier discharges

Science.gov (United States)

Lopez, Jose L.; Vezzu, Guido; Freilich, Alfred; Paolini, Bernhard

2013-08-01

The increasing usage of the feed gases of lower grade liquid oxygen (LOX) containing higher levels of trace hydrocarbon impurities in dielectric barrier discharge (DBD) for ozone generation requires a better understanding of the kinetics of the by-product formation resulting from reactions involving these hydrocarbon impurities. As a case study of hydrocarbon impurities, the kinetics of CH4 conversion in DBDs and the subsequent HNO3 formation were investigated by means of gas-phase plasma diagnostics, supported by detailed process modeling, and extensive in-situ and ex-situ by-product analysis. The by-products formation in the plasma with the presence of CH4, were found to differ significantly in oxygen-fed generators as compared to generators fed with oxygen/nitrogen mixtures. The amount of HNO3 formed depends on the concentration of NOx formed in the plasma and the amount of CH4 that is converted, but not on the O3 concentration. In the present work we have investigated CH4 concentrations of up to 1.95 wt% of the feed gas. The rate of deterioration of the overall ozone generator performance was found to be affected by the concentration of nitrogen in the oxygen/nitrogen mixture.

Diagnostic accuracy of liver fibrosis based on red cell distribution width (RDW) to platelet ratio with fibroscan in chronic hepatitis B

Science.gov (United States)

Sembiring, J.; Jones, F.

2018-03-01

Red cell Distribution Width (RDW) and platelet ratio (RPR) can predict liver fibrosis and cirrhosis in chronic hepatitis B with relatively high accuracy. RPR was superior to other non-invasive methods to predict liver fibrosis, such as AST and ALT ratio, AST and platelet ratio Index and FIB-4. The aim of this study was to assess diagnostic accuracy liver fibrosis by using RDW and platelets ratio in chronic hepatitis B patients based on compared with Fibroscan. This cross-sectional study was conducted at Adam Malik Hospital from January-June 2015. We examine 34 patients hepatitis B chronic, screen RDW, platelet, and fibroscan. Data were statistically analyzed. The result RPR with ROC procedure has an accuracy of 72.3% (95% CI: 84.1% - 97%). In this study, the RPR had a moderate ability to predict fibrosis degree (p = 0.029 with AUC> 70%). The cutoff value RPR was 0.0591, sensitivity and spesificity were 71.4% and 60%, Positive Prediction Value (PPV) was 55.6% and Negative Predictions Value (NPV) was 75%, positive likelihood ratio was 1.79 and negative likelihood ratio was 0.48. RPR have the ability to predict the degree of liver fibrosis in chronic hepatitis B patients with moderate accuracy.

Development of air fuel ratio sensor; A/F sensor no kaihatsu

Energy Technology Data Exchange (ETDEWEB)

Sakawa, T; Hori, M [Denso Corp., Aichi (Japan); Nakamura, Y [Toyota Motor Corp., Aichi (Japan)

1997-10-01

The Air Fuel Ratio Sensor (A/F sensor), which is applied to a 1997 model year Low Emission Vehicle (LEV) was developed. This sensor enables the detection of the exhaust gas air fuel ratio, both lean and rich of stoichiometric. It has an effective air fuel ratio range from 12 to 18 as required for LEV regulation. It has the fast light off, - within 20 seconds - to minimize exhaust hydrocarbon content. Further, it has fast response time, less than 200 msec, to improve the air fuel ratio controllability. 3 refs., 7 figs.

Chemistry of Volatile Organic Compounds in the Los Angeles basin: Nighttime Removal of Alkenes and Determination of Emission Ratios

Science.gov (United States)

de Gouw, J. A.; Gilman, J. B.; Kim, S.-W.; Lerner, B. M.; Isaacman-VanWertz, G.; McDonald, B. C.; Warneke, C.; Kuster, W. C.; Lefer, B. L.; Griffith, S. M.; Dusanter, S.; Stevens, P. S.; Stutz, J.

2017-11-01

We reanalyze a data set of hydrocarbons in ambient air obtained by gas chromatography-mass spectrometry at a surface site in Pasadena in the Los Angeles basin during the NOAA California Nexus study in 2010. The number of hydrocarbon compounds quantified from the chromatograms is expanded through the use of new peak-fitting data analysis software. We also reexamine hydrocarbon removal processes. For alkanes, small alkenes, and aromatics, the removal is determined by the reaction with hydroxyl (OH) radicals. For several highly reactive alkenes, the nighttime removal by ozone and nitrate (NO3) radicals is also significant. We discuss how this nighttime removal affects the determination of emission ratios versus carbon monoxide (CO) and show that previous estimates based on nighttime correlations with CO were too low. We analyze model output from the Weather Research and Forecasting-Chemistry model for hydrocarbons and radicals at the Pasadena location to evaluate our methods for determining emission ratios from the measurements. We find that our methods agree with the modeled emission ratios for the domain centered on Pasadena and that the modeled emission ratios vary by 23% across the wider South Coast basin. We compare the alkene emission ratios with published results from ambient measurements and from tunnel and dynamometer studies of motor vehicle emissions. We find that with few exceptions the composition of alkene emissions determined from the measurements in Pasadena closely resembles that of motor vehicle emissions.

A diagnostic-ratio approach to measuring beliefs about the leadership abilities of male and female managers.

Science.gov (United States)

Martell, R F; Desmet, A L

2001-12-01

This study departed from previous research on gender stereotyping in the leadership domain by adopting a more comprehensive view of leadership and using a diagnostic-ratio measurement strategy. One hundred and fifty-one managers (95 men and 56 women) judged the leadership effectiveness of male and female middle managers by providing likelihood ratings for 14 categories of leader behavior. As expected, the likelihood ratings for some leader behaviors were greater for male managers, whereas for other leader behaviors, the likelihood ratings were greater for female managers or were no different. Leadership ratings revealed some evidence of a same-gender bias. Providing explicit verification of managerial success had only a modest effect on gender stereotyping. The merits of adopting a probabilistic approach in examining the perception and treatment of stigmatized groups are discussed.

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.

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.

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

Coupling spectroscopic and chromatographic techniques for evaluation of the depositional history of hydrocarbons in a subtropical estuary

International Nuclear Information System (INIS)

Martins, César C.; Doumer, Marta E.; Gallice, Wellington C.; Dauner, Ana Lúcia L.; Cabral, Ana Caroline; Cardoso, Fernanda D.

2015-01-01

Spectroscopic and chromatographic techniques can be used together to evaluate hydrocarbon inputs to coastal environments such as the Paranaguá estuarine system (PES), located in the SW Atlantic, Brazil. Historical inputs of aliphatic hydrocarbons (AHs) and polycyclic aromatic hydrocarbons (PAHs) were analyzed using two sediment cores from the PES. The AHs were related to the presence of biogenic organic matter and degraded oil residues. The PAHs were associated with mixed sources. The highest hydrocarbon concentrations were related to oil spills, while relatively low levels could be attributed to the decrease in oil usage during the global oil crisis. The results of electron paramagnetic resonance were in agreement with the absolute AHs and PAHs concentrations measured by chromatographic techniques, while near-infrared spectroscopy results were consistent with unresolved complex mixture (UCM)/total n-alkanes ratios. These findings suggest that the use of a combination of techniques can increase the accuracy of assessment of contamination in sediments. - Highlights: • Historical inputs of hydrocarbons in a subtropical estuary were evaluated. • Spectroscopic and chromatographic methods were used in combination. • High hydrocarbon concentrations were related to anthropogenic activities. • Low hydrocarbon levels could be explained by the 1970s global oil crisis. - Spectroscopic and chromatographic techniques could be used together to evaluate hydrocarbon inputs to coastal environments

A quantum cascade laser infrared spectrometer for CO2 stable isotope analysis: Field implementation at a hydrocarbon contaminated site under bio-remediation.

Science.gov (United States)

Guimbaud, Christophe; Noel, Cécile; Chartier, Michel; Catoire, Valéry; Blessing, Michaela; Gourry, Jean Christophe; Robert, Claude

2016-02-01

Real-time methods to monitor stable isotope ratios of CO2 are needed to identify biogeochemical origins of CO2 emissions from the soil-air interface. An isotope ratio infra-red spectrometer (IRIS) has been developed to measure CO2 mixing ratio with δ(13)C isotopic signature, in addition to mixing ratios of other greenhouse gases (CH4, N2O). The original aspects of the instrument as well as its precision and accuracy for the determination of the isotopic signature δ(13)C of CO2 are discussed. A first application to biodegradation of hydrocarbons is presented, tested on a hydrocarbon contaminated site under aerobic bio-treatment. CO2 flux measurements using closed chamber method is combined with the determination of the isotopic signature δ(13)C of the CO2 emission to propose a non-intrusive method to monitor in situ biodegradation of hydrocarbons. In the contaminated area, high CO2 emissions have been measured with an isotopic signature δ(13)C suggesting that CO2 comes from petroleum hydrocarbon biodegradation. This first field implementation shows that rapid and accurate measurement of isotopic signature of CO2 emissions is particularly useful in assessing the contribution of contaminant degradation to the measured CO2 efflux and is promising as a monitoring tool for aerobic bio-treatment. Copyright © 2016. Published by Elsevier B.V.

Effects of P/Ni ratio and Ni content on performance of γ-Al{sub 2}O{sub 3}-supported nickel phosphides for deoxygenation of methyl laurate to hydrocarbons

Energy Technology Data Exchange (ETDEWEB)

Zhang, Zhena; Tang, Mingxiao; Chen, Jixiang, E-mail: jxchen@tju.edu.cn

2016-01-01

Graphical abstract: - Highlights: • The formation of AlPO{sub 4} was unfavorable for that of nickel phosphides. • The phase compositions of nickel phosphide depended on the amount of reduced P. • Catalytic activity was determined by surface Ni site density and catalyst acidity. • HDO pathway was promoted by increasing P/Ni ratio and Ni content. • Nickel phosphide gave much higher carbon yield and lower H{sub 2} consumption than Ni. - Abstract: γ-Al{sub 2}O{sub 3}-supported nickel phosphides (mNi-Pn) were prepared by the TPR method and tested for the deoxygenation of methyl laurate to hydrocarbons. The effects of the P/Ni ratio (n = 1.0–2.5) and Ni content (m = 5–15 wt.%) in the precursors on their structure and performance were investigated. Ni/γ-Al{sub 2}O{sub 3} was also studied for comparison. It was found that the formation of AlPO{sub 4} in the precursor inhibited the reduction of phosphate and so the formation of nickel phosphides. With increasing the P/Ni ratio and Ni content, the Ni, Ni{sub 3}P, Ni{sub 12}P{sub 5} and Ni{sub 2}P phases orderly formed, accompanying with the increases of their particle size and the amount of weak acid sites (mainly due to P-OH group), while the CO uptake and the amount of medium strong acid sites (mainly related to Ni sites) reached maximum on 10%Ni-P1.5. In the deoxygenation reaction, compared with Ni/γ-Al{sub 2}O{sub 3}, the mNi-Pn catalysts showed much lower activities for decarbonylation, C−C hydrogenolysis and methanation due to the ligand and ensemble effects of P. The conversion and the selectivity to n-C11 and n-C12 hydrocarbons achieved maximum on 10%Ni-P 2.0 for the 10%Ni-Pn catalysts and on 8%Ni-P2.0 for the mNi-P2.0 catalysts, while the turnover frequency (TOF) of methyl laurate mainly increased with the P/Ni ratio and Ni content. We propose that TOF was influenced by the nickel phosphide phases, the catalyst acidity and the particle size as well as the synergetic effect between the Ni site and

Ambient aromatic hydrocarbon measurements at Welgegund, South Africa

Science.gov (United States)

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

2014-07-01

observed. Air mass back trajectory analysis indicated that the lack of seasonal cycles could be attributed to patterns determining the origin of the air masses sampled. Aromatic hydrocarbon concentrations were in general significantly higher in air masses that passed over anthropogenically impacted regions. Inter-compound correlations and ratios gave some indications of the possible sources of the different aromatic hydrocarbons in the source regions defined in the paper. The highest contribution of aromatic hydrocarbon concentrations to ozone formation potential was also observed in plumes passing over anthropogenically impacted regions.

Particulate-bound polycyclic aromatic hydrocarbon sources and determinants in residential homes.

Science.gov (United States)

Cattaneo, Andrea; Fermo, Paola; Urso, Patrizia; Perrone, Maria Grazia; Piazzalunga, Andrea; Tarlassi, Jessica; Carrer, Paolo; Cavallo, Domenico Maria

2016-11-01

Human exposure to polycyclic aromatic hydrocarbons (PAHs) in indoor environments can be particularly relevant because people spend most of their time inside buildings, especially in homes. This study aimed to investigate the most important particle-bound PAH sources and exposure determinants in PM 2.5 samples collected in 19 homes located in northern Italy. Complementary information about ion content in PM 10 was also collected in 12 of these homes. Three methods were used for the identification of PAH sources and determinants: diagnostic ratios with principal component and hierarchical cluster analyses (PCA and HCA), chemical mass balance (CMB) and linear mixed models (LMMs). This combined and tiered approach allowed the infiltration of outdoor PAHs into indoor environments to be identified as the most important source in winter, with a relevant role played by biomass burning and traffic exhausts to be identified as a general source of PAHs in both seasons. Tobacco smoke exhibited an important impact on PAH levels in smokers' homes, whereas in the whole sample, cooking food and natural gas sources played a minor or negligible role. Nitrate, sulfate and ammonium were the main inorganic constituents of indoor PM 10 owing to the secondary formation of ammonium sulfates and nitrates. Copyright © 2016 Elsevier Ltd. All rights reserved.

Natural revegetation of hydrocarbon-contaminated soil in semi-arid grasslands

International Nuclear Information System (INIS)

Bizecki Robson, D.; Knight, J. D.; Farrell, R. E.; Germida, J. J.

2004-01-01

Phytoremediation, or the use of plants to degrade and contain soil contaminants is considered a cost-effective decontaminant for sites contaminated by spills in the oil and gas producing areas of Western Canada. The objective of this study was to determine if contamination by hydrocarbons changes soil properties, species composition, and species abundance when compared with uncontaminated plots, and to identify species and functional groups unique to contaminated sites that may be further screened for their hydrocarbon-degrading ability. In pursuit of these objectives the effect of contamination on coverage, litter and bare ground was examined, differences in species composition between contaminated and uncontaminated sites were assessed, and the ability to fix nitrogen, and form mycorrhiza, life form, pollination mode, seed dispersal and reproduction mode of each species was determined. Results showed less vegetation and litter cover in contaminated plots, and significantly higher soil carbon to nitrogen ratios. Species diversity was also lower on contaminated sites, although species richness was not significantly different. Self-pollinated species were significantly more common on contaminated sites. Five grasses and three forbs were identified as tolerant of hydrocarbon-contaminated soils, with two grasses -- Agropyron smithii, and Agropyron trachycaulum -- being the most promising for reclamation. The low vegetation cover on contaminated plots is attributed to high pH and carbon to nitrogen ratios, and low nitrogen and phosphorus that results from soil disturbance. High electrical conductivity is also considered to adversely affect vegetation and litter cover on contaminated sites. 54 refs., 3 tabs., 1 fig

Natural revegetation of hydrocarbon-contaminated soil in semi-arid grasslands

Energy Technology Data Exchange (ETDEWEB)

Bizecki Robson, D.; Knight, J. D.; Farrell, R. E.; Germida, J. J. [University of Saskatchewan, Dept. of Soil Science, Saskatoon, SK (Canada)

2004-01-01

Phytoremediation, or the use of plants to degrade and contain soil contaminants is considered a cost-effective decontaminant for sites contaminated by spills in the oil and gas producing areas of Western Canada. The objective of this study was to determine if contamination by hydrocarbons changes soil properties, species composition, and species abundance when compared with uncontaminated plots, and to identify species and functional groups unique to contaminated sites that may be further screened for their hydrocarbon-degrading ability. In pursuit of these objectives the effect of contamination on coverage, litter and bare ground was examined, differences in species composition between contaminated and uncontaminated sites were assessed, and the ability to fix nitrogen, and form mycorrhiza, life form, pollination mode, seed dispersal and reproduction mode of each species was determined. Results showed less vegetation and litter cover in contaminated plots, and significantly higher soil carbon to nitrogen ratios. Species diversity was also lower on contaminated sites, although species richness was not significantly different. Self-pollinated species were significantly more common on contaminated sites. Five grasses and three forbs were identified as tolerant of hydrocarbon-contaminated soils, with two grasses -- Agropyron smithii, and Agropyron trachycaulum -- being the most promising for reclamation. The low vegetation cover on contaminated plots is attributed to high pH and carbon to nitrogen ratios, and low nitrogen and phosphorus that results from soil disturbance. High electrical conductivity is also considered to adversely affect vegetation and litter cover on contaminated sites. 54 refs., 3 tabs., 1 fig.

Fetal cerebro-placental ratio and adverse perinatal outcome: systematic review and meta-analysis of the association and diagnostic performance.

Science.gov (United States)

Nassr, Ahmed Abobakr; Abdelmagied, Ahmed M; Shazly, Sherif A M

2016-03-01

The objective of this meta-analysis is to assess the value of fetal cerebro-placental Doppler ratio (CPR) in predicting adverse perinatal outcome in pregnancies with fetal growth restriction (FGR). Three databases were used: MEDLINE, EMBASE (with online Ovid interface) and SCOPUS and studies from inception to April 2015 were included. Studies that reported perinatal outcomes of fetuses at risk of FGR or sonographically diagnosed FGR that were evaluated with CPR were considered eligible. Perinatal outcomes include cesarean section (CS) for fetal distress, APGAR scores at 5 min, neonatal complications and admission to neonatal intensive care unit (NICU). Pooled data were expressed as odds ratio (OR) and confidence intervals (CI), and the summary receiver operating characteristic (SROC) curve was used to illustrate the diagnostic accuracy of CPR. Seven studies were eligible (1428 fetuses). Fetuses with abnormal CPR were at higher risk of CS for fetal distress (OR=4.49, 95% CI [1.63, 12.42]), lower APGAR scores (OR=4.01, 95% CI [2.65, 6.08]), admission to NICU (OR=9.65, 95% CI [3.02, 30.85]), and neonatal complications (OR=11.00, 95% [3.64, 15.37]) than fetuses who had normal CPR. These risks were higher among studies that included fetuses diagnosed with FGR than fetuses at risk of FGR. Abnormal CPR had higher diagnostic accuracy for adverse perinatal outcomes among "sonographically diagnosed FGR" studies than "at risk of FGR" studies. Abnormal CPR is associated with substantial risk of adverse perinatal outcomes. The test seems to be particularly useful for follow up of fetuses with sonographically diagnosed FGR.

Ambient aromatic hydrocarbon measurements at Welgegund, South Africa

Energy Technology Data Exchange (ETDEWEB)

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

2014-07-11

attributed to patterns determining the origin of the air masses sampled. Aromatic hydrocarbon concentrations were in general significantly higher in air masses that passed over anthropocentrically impacted regions. Interspecies correlations and ratios gave some indications of the possible sources for the different aromatic hydrocarbons in the source regions defined in the paper. The highest contribution of aromatic hydrocarbon concentrations to ozone formation potential was also observed in plumes passing over anthropocentrically impacted regions.

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

Enhanced NIF neutron activation diagnostics.

Science.gov (United States)

Yeamans, C B; Bleuel, D L; Bernstein, L A

2012-10-01

The NIF neutron activation diagnostic suite relies on removable activation samples, leading to operational inefficiencies and a fundamental lower limit on the half-life of the activated product that can be observed. A neutron diagnostic system measuring activation of permanently installed samples could remove these limitations and significantly enhance overall neutron diagnostic capabilities. The physics and engineering aspects of two proposed systems are considered: one measuring the (89)Zr/(89 m)Zr isomer ratio in the existing Zr activation medium and the other using potassium zirconate as the activation medium. Both proposed systems could improve the signal-to-noise ratio of the current system by at least a factor of 5 and would allow independent measurement of fusion core velocity and fuel areal density.

Seasonal variation of the particle size distribution of n-alkanes and polycyclic aromatic hydrocarbons (PAHs) in urban aerosol of Guangzhou, China.

Science.gov (United States)

Tang, X L; Bi, X H; Sheng, G Y; Tan, J H; Fu, J M

2006-06-01

Seasonal aerosol samples have been collected by Andersen Hi-Vol pumping system equipped with a five stage cascade impactor and a backup filter (size range: 10-7.2 microm, 7.2-3.0 microm, 3.0-1.5 microm, 1.5-0.95 microm, 0.95-0.49 microm, gas chromatography and PAHs were measured using gas chromatography/mass spectrometry analysis. The bimodal log-normal distributions of n-alkanes and semi-volatile PAHs were found, while for non-volatile PAHs that was unimodal, so much as the mode of semi-volatile PAHs was similar with that of the particles. The n-alkanes and PAHs were preferably associated with fine particles. C (max) (carbon number maximum) (C(22)-C(26)), CPI (carbon preference index) (1.12-1.21), U/R (unresolved to resolved components ratio) (7.42-10.7), wax% (0.9-3.12%) and the diagnostic ratios for PAHs revealed that vehicular emission was the major source of these organic compounds during the study periods, while the contribution of epicuticular waxes emitted by terrestrial plants was minor. CPI(2) (values for petrogenic hydrocarbons), CPI(3) (values for biogenic n-alkanes) and wax% revealed that the natural preferentially accumulated in the larger aerosol while the anthropogenic in the smaller. In addition, the different MMDs (mass median diameters) for n-alkanes and PAHs were observed in different seasons. The MMDs for n-alkanes and PAHs were higher in autumn/winter than those in spring/summer. The seasonal effect was related to the hydrocarbon content in the individual particulate fractions, showing a preferential association of n-alkanes and PAHs with larger particles in the autumn/winter season.

Diagnostics of capacitively-coupled hydrocarbon plasmas for deposition of diamond-like carbon films using quadrupole mass spectrometry and Langmuir probe

Science.gov (United States)

Oda, Akinori; Fukai, Shun; Kousaka, Hiroyuki; Ohta, Takayuki

2015-09-01

Diamond-like carbon (DLC) films are the hydrogenated amorphous carbon films, which contains a mixture of sp2- and sp3-bonded carbon. The DLC films have been widely used for various applications, such as automotive, semiconductors, medical devices, since have excellent material properties in lower friction, higher chemical stability, higher hardness, higher wear resistance. Until now, numerous investigations on the DLC films using plasma assisted chemical vapor deposition have been done. For precise control of coating technique of DLC films, it is enormously important to clarify the fundamental properties in hydrocarbon plasmas, as a source of hydrocarbon ions and radicals. In this paper, the fundamental properties in a low pressure radio-frequency hydrocarbon (Ar/CH4 (1 %) gas mixture) plasmas have been diagnosed using a quadrupole mass spectrometer (HIDEN ANARYTICAL Ltd., EQP-300) and Langmuir probe system (HIDEN ANARYTICAL Ltd., ESPion). This work was partly supported by KAKENHI (No.26420247), and a ``Grant for Advanced Industrial Technology Development (No.11B06004d)'' in 2011 from the New Energy and Industrial Technology Development Organization (NEDO) of Japan.

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)

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)

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)

Catalyst for reforming hydrocarbons with water vapors

International Nuclear Information System (INIS)

Nicklin, T.; Farrington, F.; Whittaker, J.R.

1979-01-01

The catalyst should reform hydrocarbons with water vapour. It consists of a carrier substance (preferably clay) on whose surface the catalytically active substances are formed. By impregnation one obtains this with a mixture of thermally destructable nickel and uranium compounds and calcination of the impregnated carrier. The catalyst is marked by a definite weight ratio of uranium to nickel (about 0.6 to 1), the addition of barium compounds and a maximum limit of these additives. All details of manufacture and the range of variations are described in detail. (UWI) [de

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.

Sources and distribution of polycyclic aromatic hydrocarbons in sediments from the Spanish northern continental shelf. Assessment of spatial and temporal trends

International Nuclear Information System (INIS)

Vinas, Lucia; Angeles Franco, M.; Antonio Soriano, J.; Jose Gonzalez, J.; Pon, Jordi; Albaiges, Joan

2010-01-01

The distribution of polycyclic aromatic hydrocarbons was determined in surface sediments collected at 36 stations along the Spanish Northern continental shelf in March and September 2003, and February 2005. Concentrations of PAHs (Σ13 parent components) were in the range of 22-47528 μg/kg dw, the highest values corresponding to coastal urban-industrial hotspots and decreasing offshore. Sediment quality guidelines (SQGs) showed that concentrations of total PAHs were below the threshold effect level (TEC) in 27 stations (81%) and above in 7, two of which (Gijon and Bilbao) were above the probable effect concentration (PEC). The detailed study of diagnostic ratios suggested a rather uniform mixture of petrogenic and pyrolytic PAH sources along the continental shelf, with a slight decrease of the latter moving westwards and offshore. In order to assess the incidence of sediment sampling on the variability of the results, selected stations were also monitored in February and September 2004 and September 2005. The average field variance of the values obtained for each station was 31% that decreased to 23% when the values were normalized to TOC. - PAHs in the Spanish Atlantic coastal sediments reflect chronic inputs of petrogenic and pyrolytic hydrocarbons, with a decrease of the latter moving westwards and offshore and representing low to moderate pollution according to established sediment quality guidelines.

Sources and distribution of polycyclic aromatic hydrocarbons in sediments from the Spanish northern continental shelf. Assessment of spatial and temporal trends

Energy Technology Data Exchange (ETDEWEB)

Vinas, Lucia, E-mail: lucia.vinas@vi.ieo.e [Instituto Espanol de Oceanografia, Centro Oceanografico de Vigo, Cabo Estai - Canido, 36200 Vigo (Spain); Angeles Franco, M.; Antonio Soriano, J.; Jose Gonzalez, J. [Instituto Espanol de Oceanografia, Centro Oceanografico de Vigo, Cabo Estai - Canido, 36200 Vigo (Spain); Pon, Jordi [Department of Environmental Chemistry, CID-CSIC, Jordi Girona Salgado, 18-26, 08034-Barcelona (Spain); Albaiges, Joan, E-mail: albqam@cid.csic.e [Department of Environmental Chemistry, CID-CSIC, Jordi Girona Salgado, 18-26, 08034-Barcelona (Spain)

2010-05-15

The distribution of polycyclic aromatic hydrocarbons was determined in surface sediments collected at 36 stations along the Spanish Northern continental shelf in March and September 2003, and February 2005. Concentrations of PAHs (SIGMA13 parent components) were in the range of 22-47528 mug/kg dw, the highest values corresponding to coastal urban-industrial hotspots and decreasing offshore. Sediment quality guidelines (SQGs) showed that concentrations of total PAHs were below the threshold effect level (TEC) in 27 stations (81%) and above in 7, two of which (Gijon and Bilbao) were above the probable effect concentration (PEC). The detailed study of diagnostic ratios suggested a rather uniform mixture of petrogenic and pyrolytic PAH sources along the continental shelf, with a slight decrease of the latter moving westwards and offshore. In order to assess the incidence of sediment sampling on the variability of the results, selected stations were also monitored in February and September 2004 and September 2005. The average field variance of the values obtained for each station was 31% that decreased to 23% when the values were normalized to TOC. - PAHs in the Spanish Atlantic coastal sediments reflect chronic inputs of petrogenic and pyrolytic hydrocarbons, with a decrease of the latter moving westwards and offshore and representing low to moderate pollution according to established sediment quality guidelines.

The prospect for fuel ion ratio measurements in ITER by collective Thomson scattering

DEFF Research Database (Denmark)

Stejner Pedersen, Morten; Korsholm, Søren Bang; Nielsen, Stefan Kragh

2012-01-01

We show that collective Thomson scattering (CTS) holds the potential to become a new diagnostic principle for measurements of the fuel ion ratio, nT/nD, in ITER. Fuel ion ratio measurements will be important for plasma control and machine protection in ITER. Measurements of ion cyclotron structures...... in CTS spectra have been suggested as the basis for a new fuel ion ratio diagnostic which would be well suited for reactor environments and capable of providing spatially resolved measurements in the plasma core. Such measurements were demonstrated in recent experiments in the TEXTOR tokamak. Here we...... conduct a sensitivity study to investigate the potential measurement accuracy of a CTS fuel ion ratio diagnostic on ITER. The study identifies regions of parameter space in which CTS can be expected to provide useful information on plasma composition, and we find that a CTS fuel ion ratio diagnostic could...

Financial ratios in diagnostic radiology practices: variability and trends.

Science.gov (United States)

Hogan, Christopher; Sunshine, Jonathan H

2004-03-01

To evaluate variation in financial ratios for radiology practices nationwide and trends in these ratios and in payments. In 1999, the American College of Radiology surveyed radiology practices by mail. The final response rate was 66%. Weighting was used to make responses representative of all radiology practices in the United States. Self-reported financial ratios (payments, charges, accounts receivable turnover) were analyzed; 449 responses had usable data on these ratios. Comparison with results of a similar 1992 survey and combined analysis with Medicare data on billed charges provided information on trends. All measures of payment collections declined sharply from 1992 to 1999, with the gross collections rate (revenues as percentage of billed charges) decreasing from 71% to 55%. Average payment for a typical radiology service decreased approximately 4% in dollar terms or approximately 19% in inflation-adjusted terms. In 1999, nonmetropolitan practices appeared to fare better than others. Among insurers, Medicaid stood out as a low and slow payer, but neither managed care nor Medicare had a consistent effect on financial ratios. The gross collections rate varied substantially across geographic areas, as did, in an inverse pattern, the level of billed charges. One-quarter of practices had accounts receivable equal to 90 or more days of billings. The opposing geographic pattern of billed charges and gross collection rate suggests that geographic variation in the latter is driven more by variation in billed charges than by variation in payment levels. Radiologists saw a substantial decrease in the real (inflation-adjusted) value of payment per service during the 1990s. The large fraction of practices with accounts receivable of 90 or more days of billings-a level considered potentially imprudent by financial management advisors-suggests that many practices should improve financial management and that state prompt-payment laws have not had a substantial positive

The Charge State of Polycyclic Aromatic Hydrocarbons across a Reflection Nebula, an H II Region, and a Planetary Nebula

Science.gov (United States)

Boersma, C.; Bregman, J.; Allamandola, L. J.

2018-05-01

Low-resolution Spitzer-IRS spectral map data of a reflection nebula (NGC 7023), H II region (M17), and planetary nebula (NGC 40), totaling 1417 spectra, are analyzed using the data and tools available through the NASA Ames PAH IR Spectroscopic Database. The polycyclic aromatic hydrocarbon (PAH) emission is broken down into PAH charge and size subclass contributions using a database-fitting approach. The resulting charge breakdown results are combined with those derived using the traditional PAH band strength ratio approach, which interprets particular PAH band strength ratios as proxies for PAH charge. Here the 6.2/11.2 μm PAH band strength ratio is successfully calibrated against its database equivalent: the {n}PAH}+}/{n}PAH}0} ratio. In turn, this ratio is converted into the PAH ionization parameter, which relates it to the strength of the radiation field, gas temperature, and electron density. Population diagrams are used to derive the {{{H}}}2 density and temperature. The bifurcated plot of the 8.6 versus 11.2 μm PAH band strength for the northwest photo dissociation region in NGC 7023 is shown to be a robust diagnostic template for the {n}PAH}+}/{n}PAH}0} ratio in all three objects. Template spectra for the PAH charge and size subclasses are determined for each object and shown to favorably compare. Using the determined template spectra from NGC 7023 to fit the emission in all three objects yields, upon inspection of the Structure SIMilarity maps, satisfactory results. The choice of extinction curve proves to be critical. Concluding, the distinctly different astronomical environments of a reflection nebula, H II region, and planetary nebula are reflected in their PAH emission spectra.

Atmospheric concentrations and phase partitioning of polycyclic aromatic hydrocarbons in Izmir, Turkey

Energy Technology Data Exchange (ETDEWEB)

Demircioglu, Eylem; Odabasi, Mustafa [Faculty of Engineering, Department of Environmental Engineering, Dokuz Eylul University, Izmir (Turkey); Sofuoglu, Aysun [Faculty of Engineering, Department of Chemical Engineering, Izmir Institute of Technology, Gulbahce-Urla (Turkey)

2011-04-15

Ambient air polycyclic aromatic hydrocarbon (PAH) samples were collected at a suburban (n = 63) and at an urban site (n = 14) in Izmir, Turkey. Average gas-phase total PAH (sum {sub 14}PAH) concentrations were 23.5 ng m{sup -3} for suburban and 109.7 ng m{sup -3} for urban sites while average particle-phase total PAH concentrations were 12.3 and 34.5 ng m{sup -3} for suburban and urban sites, respectively. Higher ambient PAH concentrations were measured in the gas-phase and sum {sub 14}PAH concentrations were dominated by lower molecular weight PAHs. Multiple linear regression analysis indicated that the meteorological parameters were effective on ambient PAH concentrations. Emission sources of particle-phase PAHs were investigated using a diagnostic plot of fluorene (FLN)/(fluorine + pyrene; PY) versus indeno[1,2,3-cd]PY/(indeno[1,2,3-cd]PY + benzo[g,h,i]perylene) and several diagnostic ratios. These approaches have indicated that traffic emissions (petroleum combustion) were the dominant PAH sources at both sites for summer and winter seasons. Experimental gas-particle partition coefficients (K{sub P}) were compared to the predictions of octanol-air (K{sub OA}) and soot-air (K{sub SA}) partition coefficient models. The correlations between experimental and modeled K{sub P} values were significant (r{sup 2} = 0.79 and 0.94 for suburban and urban sites, respectively, p < 0.01). Octanol-based absorptive partitioning model predicted lower partition coefficients especially for relatively volatile PAHs. However, overall there was a relatively good agreement between the measured K{sub P} and soot-based model predictions. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Microbial activity and soil organic matter decay in roadside soils polluted with petroleum hydrocarbons

Science.gov (United States)

Mykhailova, Larysa; Fischer, Thomas; Iurchenko, Valentina

2015-04-01

It has been demonstrated previously that hydrocarbon addition to soil provokes soil organic matter priming (Zyakun et al., 2011). It has further been shown that petroleum hydrocarbons deposit to roadside soils bound to fine mineral particles and together with vehicle spray (Mykhailova et al., 2014), and that hydrocarbon concentrations decrease to safe levels within the first 15 m from the road, reaching background concentrations at 60-100 m distance (Mykhailova et al., 2013). It was the aim of this study to (I) identify the bioavailability of different petroleum hydrocarbon fractions to degradation and to (II) identify the native (i.e. pedogenic) C fraction affected by hydrocarbon-mediated soil organic matter priming during decay. To address this aim, we collected soil samples at distances from 1 to 100 m (sampling depth 15 cm) near the Traktorostroiteley avenue and the Pushkinskaya street in Kharkov, as well as near the country road M18 near Kharkov, Ukraine. The roads have been under exploitation for several decades, so microbial adaptation to enhanced hydrocarbon levels and full expression of effects could be assumed. The following C fractions were quantified using 13C-CP/MAS-NMR: Carbohydrates, Proteins, Lignin, Aliphates, Carbonyl/Carboxyl as well as black carbon according to Nelson and Baldock (2005). Petroleum hydrocarbons were determind after hexane extraction using GC-MS and divided into a light fraction (chain-length C27, Mykhailova et al., 2013). Potential soil respiration was determined every 48 h by trapping of CO2 evolving from 20 g soil in NaOH at 20 ° C and at 60% of the maximum water holding capacity and titration after a total incubation period of 4 weeks in the lab. It was found that soil respiration positively correlated with the ratio of the light fraction to the sum of medium and heavy fractions of petroleum hydrocarbons, which indicates higher biodegradation primarily of the light petroleum hydrocarbon fraction. Further, soil respiration was

Bioremediation of soils contaminated by hydrocarbons at the coastal zone of “Punta Majagua”.

Directory of Open Access Journals (Sweden)

Jelvys Bermúdez Acosta

2012-03-01

Full Text Available The purpose of this research was to describe and assess the main results in the process of bioremediation of 479 m3 of petroleum residuals spilled on the soil and restrained into four deposits of fuel on the coastal zone of “Punta Majagua”, Cienfuegos. The volume of hydrocarbons spilled and contained into the tanks was determined by means of their previous mixture with fertile ground in a ratio of 3/1. The hydrocarbons were disposed in a bioremediation area of 115 m X 75m built in situ. In turn 54, 5 m3 of BIOIL - FC were applied, which were fermented in an industrial bioreactor of 12000 L. An initial sampling was carried out registering values of total hydrocarbons (HTP higher than 41880 mg/kg, with high concentrations of Saturated hydrocarbons, aromatics, resins, asphaltens (SARA. Three subsequent samples were taken with a sampling interval of 0, 45, 90 and 120 days of the application. An average concentration of 1884.57 mg/kg of total hydrocarbons was obtained at 120 days with an average removal rate of 94.8%, moreover values of 94.6%, 90.78%, 86.99% y 79.9% of SARA were respectively reported.

Development of a two-wavelength IR laser absorption diagnostic for propene and ethylene

Science.gov (United States)

Parise, T. C.; Davidson, D. F.; Hanson, R. K.

2018-05-01

A two-wavelength infrared laser absorption diagnostic for non-intrusive, simultaneous quantitative measurement of propene and ethylene was developed. To this end, measurements of absorption cross sections of propene and potential interfering species at 10.958 µm were acquired at high-temperatures. When used in conjunction with existing absorption cross-section measurements of ethylene and other species at 10.532 µm, a two-wavelength diagnostic was developed to simultaneously measure propene and ethylene, the two small alkenes found to generally dominate the final decomposition products of many fuel hydrocarbon pyrolysis systems. Measurements of these two species is demonstrated using this two-wavelength diagnostic scheme for propene decomposition between 1360 and 1710 K.

Isotope reversals in hydrocarbon gases of natural shale systems and well head production data

Energy Technology Data Exchange (ETDEWEB)

Berner, U.; Schloemer, S.; Stiller, E. [Bundesanstalt fuer Geowissenschaften und Rohstoffe (BGR), Hannover (Germany); Marquardt, D. [Rijksuniversiteit Utrecht (Netherlands)

2013-08-01

Relationships between gas geochemical signatures and the thermal maturity of source rocks containing aquatic organic matter are based on on pyrolysis experiments and have been successfully used in conventional hydrocarbon exploration since long. We demonstrate how these models can be applied to the evaluation of unconventional shale resources. For this purpose hydrocarbon gases have been extracted from low and high mature source rocks (type II kerogens) using laboratory desorption techniques. We determined the molecular composition of the gases as well as the carbon isotope ratios of methane to propane. In the extracted gases we observe an increase of {sup 13}C content in methane with increasing dry gas ratio (C1/{Sigma}C1-6). The carbon isotope ratios of ethane and propane initially increase with increasing dryness but start to become isotopically lighter above a dry gas ratio of 0.8. We show that oil-to-gas cracking explains the observed gas geochemical data, and that mixing between gases from different processes is a key factor to describe natural hydrocarbon systems of shales. However, data from published case studies using well head gases which show 'isotope roll-over' effects indicate that the isotopic reversal observed in well head samples deviate from those observed in natural shale systems in a fundamental way. We show that isotope reversals related to well head gases are best explained by an additional isotope fractionation effect induced through hydraulic fracturing and gas migration from the shale to the well head. Although, this induced isotope fractionation is an artifact which obscures isotopic information of natural systems to a large extend, we suggest a simple classification scheme which allows distinguishing between hot and cool spot areas using well head or mud line gas data. (orig.)

Low-maturity Kulthieth Formation coal : a possible source of polycyclic aromatic hydrocarbons in benthic sediment of the Northern Gulf of Alaska

International Nuclear Information System (INIS)

Van Kooten, G.K.; Short, J.W.; Kolak, J.J.

2002-01-01

This study addressed the issue of sources of hydrocarbons for benthic sediments in the Gulf of Alaska (GOA) with particular reference to the application of forensic geology to identify end members and to explain the geologic setting and processes affecting the system. Native coals and natural seep oils have been questioned in the past decade as possible sources of background hydrocarbons because the pattern of relative polycyclic aromatic hydrocarbon (PAH) abundance characteristic of benthic GOA sediments is inconsistent with patterns typical of weathered seep oils. Native coal has also been dismissed as a pollution source because ratios of labile hydrocarbons to total organic carbon for Bering River coal field (BRCF) sources are too low to be consistent with GOA sediments. The authors present evidence that perhaps native coal has been prematurely dismissed as a pollution source because BRCF coals do not represent adequately the geochemical signatures of coals elsewhere in the Kulthieth Formation which have much higher PAH:TOC ratios. The patterns of labile hydrocarbons in these low thermal maturity coals indicate a genetic relationship between Kulthieth Formation coals and nearby oil seeps on the Sullivan anticline. Analysis of the coal suggests it is a significant source of PAH, and it was cautioned that source models that do not include this source will underestimate the contribution of native coals to the background hydrocarbon signature in the Gulf of Alaska. 32 refs., 2 tabs., 8 figs

The influence of cyclic structure on the radiolysis of hydrocarbons

International Nuclear Information System (INIS)

Foeldiak, G.; Cserep, Gy.; Horvath, Zs.; Wojnarovits, L.

1975-01-01

Aliphatic and cyclic C 3 -C 12 alkanes and alkenes have been irradiated in liquid phase by a 60 Co-γ-source with the nominal activity of 80 000 Ci. The dose rate was 1-2 Mrad/hr, the doses were between 0 and 10 Mrad. The following conclusions can be drawn from the experiments: 1., While no significant difference can be observed between radiolytic decomposition of n-hydrocarbon homologues, that of cyclic hydrocarbons is the function of the size of the ring. 2., Reactivity of cyclic hydrocarbons is influenced not only by their surplus enthalpy of formation (strain energy) but also by the individual components of this surplus enthalpy, e.g. bond deformation or repulsion between hydrogen atoms. 3., The overall yield of decomposition of higher than C 4 straightchain and cyclic alkanes activated by radiation and reacting via either C-C or C-H fission is approximately constant, with a G value of 6.5+-0.5. The structure of the molecules affects mainly the ratio of C-C and C-H bond rupture, i.e. these two processes are in competition. 4., Hydrogen yields from alkenes are affected mainly by the order and number of allylic C-H bonds, and by the possibility of the formation of allyl-type radicals. This latter is facilitated by ''free'' rotation in the case of open-chain hydrocarbons whereas it is hindered in the case of small and medium size cycles. (K.A.)

Distribution and sources of n-alkanes and polycyclic aromatic hydrocarbons in shellfish of the Egyptian Red Sea coast

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Ahmed El Nemr

2016-06-01

Full Text Available Aromatic hydrocarbons and n-alkanes were analyzed in shellfish collected from 13 different sites along the Egyptian Red Sea coast. All samples were analyzed for n-alkanes (C8–C40 and polycyclic aromatic hydrocarbons (EPA list of PAHs. n-Alkanes in shellfish samples from 13 locations were found to be in the range of 71.0–701.1 ng/g with a mean value of 242.2 ± 192.1 ng/g dry wt. Different indices were calculated for the n-alkanes to assess their sources. These were carbon preference index (CPI, average chain length (ACL, terrigenous/aquatic ratio (TAR, natural n-alkane ratio (NAR and proxy ratio (Paq. Most of the collected samples of n-alkanes were discovered to be from natural sources. Aromatic hydrocarbons (16 PAHs from 13 sites varied between 1.3 and 160.9 ng/g with an average of 47.9 ± 45.5 ng/g dry wt. Benzo(apyrine (BaP, a cancer risk assessment, was calculated for the PAHs and resulted in ranges between 0.08 and 4.47 with an average of 1.25 ng/g dry wt.

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.

Study of mixtures based on hydrocarbons used in ORC (Organic Rankine Cycle) for engine waste heat recovery

International Nuclear Information System (INIS)

Shu, Gequn; Gao, Yuanyuan; Tian, Hua; Wei, Haiqiao; Liang, Xingyu

2014-01-01

For high temperature ORC (Organic Rankine Cycle) used in engine waste heat recovery, it's very critical to select a high temperature working fluid. HCs (Hydrocarbons) usually have excellent cycle performance, but the flammability limits their practical application. Considering that some retardants can be used to suppress flammability, the paper presents an application of mixtures based on hydrocarbons blending with refrigerant retardants to engine waste heat ORC. Three pure hydrocarbons (cyclopentane, cyclohexane, benzene) and two retardants (R11, R123) are selected for combination. Thermal efficiency and exergy loss are selected as the main objective functions. Based on thermodynamic model, the effects of retardants mass fraction, evaporation temperature and IHE (internal heat exchanger) are investigated. Results show that zeotropic mixtures do have higher thermal efficiency and lower exergy loss than pure fluids, at a certain mixture ratio. There exists the OMR (optimal mixture ratio) for different mixtures, and it changes with the evaporation temperature. When adding IHE to system, cycle performance could be obviously improved, and for benzene/R11 (0.7/0.3), the efficiency growth is about 7.12%∼9.72%. Using it, the maximum thermal efficiency of the system can achieve 16.7%, and minimum exergy loss is only 30.76 kW. - Highlights: • A theoretical analysis of Organic Rankine Cycle for engine exhaust heat recovery is proposed. • Mixtures based on hydrocarbons as working fluids have been suggested. • Effects of the IHE (internal heat exchanger) on ORC system are investigated. • OMR (Optimal mixture ratio) changes with the evaporation temperature. • Using the system, maximum thermal efficiency can achieve 16.7%

Hydrocarbon pollution fixed to combined sewer sediment: a case study in Paris.

Science.gov (United States)

Rocher, Vincent; Garnaud, Stéphane; Moilleron, Régis; Chebbo, Ghassan

2004-02-01

Over a period of two years (2000-2001), sediment samples were extracted from 40 silt traps (STs) spread through the combined sewer system of Paris. All sediment samples were analysed for physico-chemical parameters (pH, organic matter content, grain size distribution), with total hydrocarbons (THs) and 16 polycyclic aromatic hydrocarbons (PAHs) selected from the priority list of the US-EPA. The two main objectives of the study were (1) to determine the hydrocarbon contamination levels in the sediments of the Paris combined sewer system and (2) to investigate the PAH fingerprints in order to assess their spatial variability and to elucidate the PAH origins. The results show that there is some important inter-site and intra-site variations in hydrocarbon contents. Despite this variability, TH and PAH contamination levels (50th percentile) in the Parisian sewer sediment are estimated at 530 and 18 microg g(-1), respectively. The investigation of the aromatic compound distributions in all of the 40 STs has underlined that there is, at the Paris sewer system scale, a homogeneous PAH background pollution. Moreover, the study of the PAH fingerprints, using specific ratios, suggests the predominance of a pyrolytic origin for those PAHs fixed to the sewer sediment.

Bioavailability of polycyclic aromatic hydrocarbons (PAHs) to short-neck clam (Paphia undulata) from sediment matrices in mudflat ecosystem of the west coast of Peninsular Malaysia.

Science.gov (United States)

Keshavarzifard, Mehrzad; Zakaria, Mohamad Pauzi; Hwai, Tan Shau

2017-06-01

The bioaccumulation and bioavailability of polycyclic aromatic hydrocarbons (PAHs) were characterized in sediment and Paphia undulata (short-neck clam) from six mudflat areas in the west coasts of Peninsular Malaysia. The concentrations of total PAHs varied from 357.1 to 6257.1 and 179.9 ± 7.6 to 1657.5 ± 53.9 ng g -1 dry weight in sediment and short-neck clam samples, respectively. PAHs can be classified as moderate to very high level of pollution in sediments and moderate to high level of pollution in short-neck clams. The diagnostic ratios of individual PAHs and principal component analysis indicate both petrogenic and pyrogenic sources with significant dominance of pyrogenic source. The first PAHs biota-sediment accumulation factors and relative biota-sediment accumulation factors data for short-neck clam were obtained in this study, indicating a preferential accumulation of lower molecular weight PAHs. Evaluation of PAH levels in sediments and short-neck clams indicates that short-neck clam could be introduced as a good biomonitor in mudflats. The results also demonstrated that under environmental conditions, the sedimentary load of hydrocarbons appears to be one of the factors controlling their bioavailability to biota.

Selective transformation of syngas into gasoline-range hydrocarbons over mesoporous H-ZSM-5-supported cobalt nanoparticles.

Science.gov (United States)

Cheng, Kang; Zhang, Lei; Kang, Jincan; Peng, Xiaobo; Zhang, Qinghong; Wang, Ye

2015-01-26

Bifunctional Fischer-Tropsch (FT) catalysts that couple uniform-sized Co nanoparticles for CO hydrogenation and mesoporous zeolites for hydrocracking/isomerization reactions were found to be promising for the direct production of gasoline-range (C5-11 ) hydrocarbons from syngas. The Brønsted acidity results in hydrocracking/isomerization of the heavier hydrocarbons formed on Co nanoparticles, while the mesoporosity contributes to suppressing the formation of lighter (C1-4 ) hydrocarbons. The selectivity for C5-11 hydrocarbons could reach about 70 % with a ratio of isoparaffins to n-paraffins of approximately 2.3 over this catalyst, and the former is markedly higher than the maximum value (ca. 45 %) expected from the Anderson-Schulz-Flory distribution. By using n-hexadecane as a model compound, it was clarified that both the acidity and mesoporosity play key roles in controlling the hydrocracking reactions and thus contribute to the improved product selectivity in FT synthesis. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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.

Petroleum Hydrocarbon Profiles of Water and Sediment of Algoa Bay, Eastern Cape, South Africa

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Abiodun O. Adeniji

2017-10-01

Full Text Available Petroleum hydrocarbon profiles of water and sediment samples of Algoa Bay in the Eastern Cape Province of South Africa were assessed using standard analytical procedures. Water (from surface and bottom levels and sediment samples were collected from five locations in the bay from February to June 2016. Extraction of the petroleum hydrocarbons from the water and sediment samples collected was achieved using liquid-liquid and Soxhlet extraction techniques, respectively, followed by column clean up. Target compounds were analytically determined with gas chromatography–flame ionization detector (GC-FID and quantified by integrating the areas of both the resolved and unresolved components. Physicochemical properties of the water samples were also determined on site using a SeaBird 19plusV2 CTD SBE 55 device. Estimated limit of detection, limit of quantitation and relative standard deviation for the 35 n-alkane standards ranged from 0.06 to 0.13 μg/L, 0.30 to 0.69 μg/L and 3.61 to 8.32%, respectively. Results showed that total petroleum hydrocarbon (TPH varied from 45.07 to 307 μg/L in the water and 0.72 to 27.03 mg/kg in the sediments. The mean concentrations of TPH in both the water and sediment samples from Algoa Bay revealed a slight level of pollution. The diagnostic indices used showed that the hydrocarbons in the area were from both biogenic and anthropogenic sources. Hence, there is need for adequate regulation and control of all activities contributing to the levels of petroleum hydrocarbon in the marine environment for the safety of human, aquatic and wild lives in the area.

Petroleum Hydrocarbon Profiles of Water and Sediment of Algoa Bay, Eastern Cape, South Africa.

Science.gov (United States)

Adeniji, Abiodun O; Okoh, Omobola O; Okoh, Anthony I

2017-10-20

Petroleum hydrocarbon profiles of water and sediment samples of Algoa Bay in the Eastern Cape Province of South Africa were assessed using standard analytical procedures. Water (from surface and bottom levels) and sediment samples were collected from five locations in the bay from February to June 2016. Extraction of the petroleum hydrocarbons from the water and sediment samples collected was achieved using liquid-liquid and Soxhlet extraction techniques, respectively, followed by column clean up. Target compounds were analytically determined with gas chromatography-flame ionization detector (GC-FID) and quantified by integrating the areas of both the resolved and unresolved components. Physicochemical properties of the water samples were also determined on site using a SeaBird 19plusV2 CTD SBE 55 device. Estimated limit of detection, limit of quantitation and relative standard deviation for the 35 n -alkane standards ranged from 0.06 to 0.13 μg/L, 0.30 to 0.69 μg/L and 3.61 to 8.32%, respectively. Results showed that total petroleum hydrocarbon (TPH) varied from 45.07 to 307 μg/L in the water and 0.72 to 27.03 mg/kg in the sediments. The mean concentrations of TPH in both the water and sediment samples from Algoa Bay revealed a slight level of pollution. The diagnostic indices used showed that the hydrocarbons in the area were from both biogenic and anthropogenic sources. Hence, there is need for adequate regulation and control of all activities contributing to the levels of petroleum hydrocarbon in the marine environment for the safety of human, aquatic and wild lives in the area.

Automatic reduction of the hydrocarbon reaction mechanisms in fusion edge plasmas

International Nuclear Information System (INIS)

Dauwe, A.; Tytgadt, M.; Reiter, D.; Baelmans, M.

2006-11-01

For predictions of the tritium inventory in future fusion devices like ITER, the amount of eroded carbon and the hydrogen concentrations in co-deposited hydrocarbon layers have to be predicted quantitatively. Predictions about the locations of co-deposited layers are also necessary in order to design deposition diagnostics and layer removal methods. This requires a detailed physical understanding of the erosion and carbon migration processes, and computer simulations. For accurate simulation the multi-species code EIRENE would require to include over 50 participating species. Because such a calculation is computationally prohibitive current codes are being reduced, typically in an ad hoc fashion. In this work the potential of the mathematically sound method of intrinsic low dimensional manifolds (ILDM) for computational speed-up of the hydrocarbon transport problem simulation is thoroughly investigated. It is basically the Monte Carlo implementation of EIRENE that makes this task so challenging. As the method can substantially ameliorate the results in comparison to the conventional reduction mechanisms a step towards ILDM-reduced kinetics is conceived and tested. (orig.)

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

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.

Identification of emission sources of particle-bound polycyclic aromatic hydrocarbons in the vicinity of the industrial zone of the city of Novi Sad

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Jovčić Nataša S.

2013-01-01

Full Text Available Data on polycyclic aromatic hydrocarbons (PAHs in ambient air accessed at selected locations in the vicinity of the industrial zone of the city of Novi Sad, Serbia, have been presented and analyzed in order to determine seasonal and spatial variations and to identify emission sources of particle-bound PAHs. Previous studies have demonstrated that the major contributors of PAHs in urban areas are the emissions from vehicle exhaust, and emissions releases from industrial processes like aluminium production, creosote and wood preservation, waste incineration, cement manufacture, petrochemical and related industries, commercial heat/power production etc. The sampling campaigns have been conducted at three sampling sites, during the two 14-day periods. The first site was situated near industrial area, with a refinery, power plant and heavy-traffic road in the vicinity. The second site was located nearby the heavy traffic area, especially busy during the rush hour. The third site was residential district. Summer sampling period lasted from June 26th to July 10th 2008, while sampling of ambient air during the winter was undertaken from January 22nd to February 5th 2009. Eighty-four (84 air samples were collected using a high volume air sampler TCR Tecora H0649010/ECHO. 16 US EPA polycyclic aromatic hydrocarbons were determined in all samples using a gas chromatographer with a mass spectrometer as a detector (Shimatzu MDGC/GCMS-2010. The total average concentrations of PAHs ranged from 1.21 to 1.77 ng/m3 during the summer period and from 6.31 to 7.25 ng/m3 in the winter. Various techniques, including diagnostic ratio (DR and principal component analysis (PCA, have been used to define and evaluate potential emission sources of PAHs. Diagnostic ratio analysis indicated that vehicles, diesel or/and gasoline, industrial and combustion emissions were sources of PAHs in the vicinity of the industrial zone. Additionally, principal component analysis was used

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.

Impact of Increased Thermokarst Activity on Polycyclic Aromatic Compound (PAC) Accumulation in Sediment of Lakes in the Hydrocarbon-Rich Uplands Adjacent to the Mackenzie Delta, NT, Canada

Science.gov (United States)

Eickmeyer, D.; Thienpont, J. R.; Blais, J. M.

2017-12-01

In ecologically sensitive, hydrocarbon-rich regions like the western Canadian Arctic, environmental monitoring of oil and gas development often focuses on both direct and unintentional consequences of increased exploration and extraction of hydrocarbon resources. However, proper assessments of impact from these activities could be confounded by natural petrogenic sources in permafrost-rich regions where increased thermokarst activity results in permafrost exposure and erosion of hydrocarbon-rich deposits. Using a paired-lake design in the tundra uplands adjacent to the Mackenzie Delta, NT, we examined 4 lakes with retrogressive thaw slump scars along their shores, and 4 nearby undisturbed reference lakes, focusing on polycyclic aromatic compound (PAC) deposition and composition in the sediment. Total organic carbon (TOC)-normalized concentrations for parent and alkylated PACs were higher in surface sediments of slump-affected lakes than the reference lakes. This followed the pattern previously observed for persistent organic pollutants in these lakes where presence of thaw slumps on the lake shore was associated with lower TOC content in the water column, resulting in a smaller pool of available organic carbon, leading to higher PAC concentrations. Diagnostic ratios of specific PACs also suggested the sediment of slump-affected lakes had greater influence from petroleum-based PAC sources than their reference counterparts. This interpretation was corroborated by a principle components analysis of the metal content in the sediment. Slump-affected lakes were enriched in metals related to shale-based, Quaternary deposits of the Mackenzie Basin (e.g. Ca, Sr, Mg) when compared to reference lakes where these surficial materials were not exposed by thermokarst activity. Higher PAC concentrations and composition indicative of petrogenic sources observed in sediment of slump-affected lakes were best explained as a combination of low TOC availability and increased inputs of

Graz Endocrine Causes of Hypertension (GECOH study: a diagnostic accuracy study of aldosterone to active renin ratio in screening for primary aldosteronism

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Dobnig Harald

2009-04-01

Full Text Available Abstract Background Primary aldosteronism (PA affects approximately 5 to 10% of all patients with arterial hypertension and is associated with an excess rate of cardiovascular complications that can be significantly reduced by a targeted treatment. There exists a general consensus that the aldosterone to renin ratio should be used as a screening tool but valid data about the accuracy of the aldosterone to renin ratio in screening for PA are sparse. In the Graz endocrine causes of hypertension (GECOH study we aim to prospectively evaluate diagnostic procedures for PA. Methods and design In this single center, diagnostic accuracy study we will enrol 400 patients that are routinely referred to our tertiary care center for screening for endocrine hypertension. We will determine the aldosterone to active renin ratio (AARR as a screening test. In addition, all study participants will have a second determination of the AARR and will undergo a saline infusion test (SIT as a confirmatory test. PA will be diagnosed in patients with at least one AARR of ≥ 5.7 ng/dL/ng/L (including an aldosterone concentration of ≥ 9 ng/dL who have an aldosterone level of ≥ 10 ng/dL after the saline infusion test. As a primary outcome we will calculate the receiver operating characteristic curve of the AARR in diagnosing PA. Secondary outcomes include the test characteristics of the saline infusion test involving a comparison with 24 hours urine aldosterone levels and the accuracy of the aldosterone to renin activity ratio in diagnosing PA. In addition we will evaluate whether the use of beta-blockers significantly alters the accuracy of the AARR and we will validate our laboratory methods for aldosterone and renin. Conclusion Screening for PA with subsequent targeted treatment is of great potential benefit for hypertensive patients. In the GECOH study we will evaluate a standardised procedure for screening and diagnosing of this disease.

Serum Steroid Ratio Profiles in Prostate Cancer: A New Diagnostic Tool Toward a Personalized Medicine Approach.

Science.gov (United States)

Albini, Adriana; Bruno, Antonino; Bassani, Barbara; D'Ambrosio, Gioacchino; Pelosi, Giuseppe; Consonni, Paolo; Castellani, Laura; Conti, Matteo; Cristoni, Simone; Noonan, Douglas M

2018-01-01

Serum steroids are crucial molecules altered in prostate cancer (PCa). Mass spectrometry (MS) is currently the elected technology for the analysis of steroids in diverse biological samples. Steroids have complex biological pathways and stoichiometry and it is important to evaluate their quantitative ratio. MS applications to patient hormone profiling could lead to a diagnostic approach. Here, we employed the Surface Activated Chemical Ionization-Electrospray-NIST (SANIST) developed in our laboratories, to obtain quantitative serum steroid ratio relationship profiles with a machine learning Bayesian model to discriminate patients with PCa. The approach is focused on steroid relationship profiles and disease association. A pilot study on patients affected by PCa, benign prostate hypertrophy (BPH), and control subjects [prostate-specific antigen (PSA) lower than 2.5 ng/mL] was done in order to investigate the classification performance of the SANIST platform. The steroid profiles of 71 serum samples (31 controls, 20 patients with PCa and 20 subjects with benign prostate hyperplasia) were evaluated. The levels of 10 steroids were quantitated on the SANIST platform: Aldosterone, Corticosterone, Cortisol, 11-deoxycortisol, Androstenedione, Testosterone, dehydroepiandrosterone, dehydroepiandrosterone sulfate (DHEAS), 17-OH-Progesterone and Progesterone. We performed both traditional and a machine learning analysis. We show that the machine learning approach based on the steroid relationships developed here was much more accurate than the PSA, DHEAS, and direct absolute value match method in separating the PCa, BPH and control subjects, increasing the sensitivity to 90% and specificity to 84%. This technology, if applied in the future to a larger number of samples will be able to detect the individual enzymatic disequilibrium associated with the steroid ratio and correlate it with the disease. This learning machine approach could be valid in a personalized medicine

Optical diagnostics in the advanced test accelerator (ATA) environment

International Nuclear Information System (INIS)

Chong, Y.P.; Cornish, J.P.; Donnelly, D.

1987-05-01

The ATA is a 50-MeV, 10-kA, 70-ns pulsed electron beam accelerator that generates an extremely harsh environment for diagnostic measurements. Diagnostic targets placed in the beamline are subject to damage, frequently being destroyed by a single pulse. High radiation (x-ray, gamma, and neutron) and electromagnetic interference levels preclude placing components near the beamline that are susceptible to radiation damage. Examples of such components are integrated circuit elements, hydrocarbons such as Teflon insulation, and optical components that darken, resulting in transmission loss. Optical diagnostics play an important part in measuring experimental parameters such as the beam current density profile. A large number of optical lines of sight (LOS) are routinely deployed along the experimental beamlines that use the ATA beam. Gated TV cameras are located outside the accelerator tunnel, because the tunnel is inaccessible during operations. We will describe and discuss the difficulties, problems, and solutions encountered in making optical measurements in the ATA environment

Optimising the bio-piling of weathered hydrocarbons within a risk management framework

International Nuclear Information System (INIS)

Hough, R.; Brassington, K.; Sinke, A.; Crossley, J.; Paton, G.; Semple, K.; Risdon, G.; Jacobson, Ch.; Daly, P.; Jackman, S.; Lethbridge, G.; Pollard, S.

2005-01-01

Thirty years of research into petroleum microbiology and bio-remediation have bypassed an important observation - that many hydrocarbon contaminated sites posing potential risks to human health harbour weathered, 'mid-distillate' or heavy oils rather than 'fresh product'. Ex-situ bio-piling is an important technology for treating soils contaminated with weathered hydrocarbons. However, its performance continues to be represented by reference to reductions in the hydrocarbon 'load' in the soils being treated, rather than reductions in the risks posed by the hydrocarbon contamination. The absence of 'risk' from the vocabulary of many operators and remediation projects reduces stakeholder (regulatory, investor, landowner, and public) confidence in remediation technologies, and subsequently limits the market potential of these technologies. Stakeholder confidence in the bio-piling of weathered hydrocarbons may be improved by demonstrating process optimisation within a validated risk management framework. To address these issues, a consortium led by Cranfield University's Integrated Waste Management Centre has secured funding from the UK Government's Bio-remediation LINK programme. Project PROMISE (involving BP, SecondSite Regeneration Ltd., Dew Remediation Ltd., TES Bretby (Mowlem Group), technology translators PERA, and academics from Aberdeen, Cranfield and Lancaster Universities) aims to improve market confidence in bio-piling by demonstrating how this treatment may be applied within a risk management context. For weathered hydrocarbons in particular, the underpinning scientific components of process control, waste diagnostics, environmental fate modelling, and risk assessment have yet to be fully integrated to allow bio-piling projects to be verified with improved confidence. The Joint Research Council Review of Bio-remediation recognised this in calling explicitly for the positioning of bio-remediation within a risk management framework. The PERF report (Thermo

Seasonal Variations and Sources of Airborne Polycyclic Aromatic Hydrocarbons (PAHs in Chengdu, China

Directory of Open Access Journals (Sweden)

Ju Yang

2018-02-01

Full Text Available The concentrations of polycyclic aromatic hydrocarbons (PAHs in the air of Chengdu, a southwest city of China, were determined from March 2015 to February 2016. Here, two diagnostic ratios (DR were determined and a principal component analysis/multiple linear regression (PCA/MLR analysis was performed to identify the sources of PAHs during the four seasons. The gaseous and particle phase samples were analyzed separately. The sampled air had a gas-to particle ratio of 4.21, and between 18.7% and 31.3% of the total detected PAHs were found in the particulate phase. The total concentration of all 16-PAHs combined (gas + particles varied from 176.94 in summer to 458.95 ng·m−3 in winter, with a mean of 300.35 ± 176.6 ng·m−3. In the gas phase, phenanthrene(Phe was found at the highest concentrations in all four seasons, while benzo[b]fluoranthene(BbF and (in winter chrysene(Chr were the highest in the particle phase. The DR of Fluroanthene (Flua/(Flua + Pyrene (Pyr was higher in the gas phase than in the particle phase, while the Indeno[1,2,3-cd]pyrene(IcdP/(IcdP + Benzo[ghi]perylene (BghiP ratio was more variable in the gas than that in the particle phase. The main sources for both phases were a mixture of liquid fossil fuel combustion and the burning of biomass and coal, with clear seasonal variation. Principal Component Analysis/Multiple Linear Regression (PCA/MLR analysis identified the main PAH sources as coal burning (52% with motor vehicle exhaust and coke (48% in spring; coal (52%, coke (21%, and motor vehicle exhaust (27% in summer; coal (47%, vehicle exhaust (34%, and coke (19% in autumn; and coal (58% and vehicle exhaust (42% in winter.

Identifying the source of petroleum pollution in sediment cores of southwest of the Caspian Sea using chemical fingerprinting of aliphatic and alicyclic hydrocarbons.

Science.gov (United States)

Shirneshan, Golshan; Bakhtiari, Alireza Riyahi; Memariani, Mahmoud

2017-02-15

In this study, the concentration and sources of aliphatic and petroleum markers were investigated in 105 samples of Anzali, Rezvanshahr and Astara cores from the southwest of Caspian Sea. Petroleum importation was diagnosed as a main source in most depths of cores by the results of unresolved complex mixture, carbon preference index and hopanes and steranes. From the chemical diagnostic parameters, petroleum inputs in sediment of cores were determined to be different during years and the sources of hydrocarbons in some sections differed than Anzali and Turkmenistan and Azerbaijan oils. Diagenic ratios in most sediments of upper and middle sections in Astara core were determined to be highly similar to those of Azerbaijan oil, while the presence of Turkmenistan and Anzali oils were detected in a few sections of Anzali and Rezvanshahr cores and only five layers of downer section in Anzali core, respectively. Copyright © 2016. Published by Elsevier Ltd.

Diagnostic value of serum free PSA and the ratio of free to total PSA in the diagnosis of prostate cancer

International Nuclear Information System (INIS)

Qiu Ningyan; Zhang Jingxin; Wu Jinchang; Gong Yiming; Li Huiping

2005-01-01

In order to evaluate the value of free prostate specific antigen (FPSA) and F/T PSA ratio in differential diagnosis of benign prostate hyperplasia (BPH) from prostate cancer (PC), serum FPSA and TPSA levels were measured in 85 patients with PC, 97 BPH and 89 healthy volunteers by chemiluminescence enzyme immunoassay (CLEIA), and the ratio of F/T PSA was calculated. The results showed that serum FPSA and TPSA levels were increased in healthy volunteers of 41-88 years old and were significantly higher in healthy volunteers of 61-88 years old than that in 20-40 gear old (P 10.0 μg/L were 65.0%, 30.9% and 4.1%, respectively, while they were 5.9%, 20.0% and 74.1% in PC patients (P<0.01). When the TPSA value was between 4.0-10.0 μg/L and the ratio of F/T PSA was at 0.10 and below, the probability of PC was larger(88.9%). But the ratio of F/T PSA was at 0.25 and above, the probability of PC was smaller(6.20%). Serum FPSA and TPSA both increased with age in healthy volunteers of 41-88 years old and were positively correlated with age. There were about 30.9% of BPH and 20.0% of PC patients with overlapping of TPSA level. Our conclusion is that the F/T PSA ratio can significantly enhance the specificity for PC diagnosis, especially when the TPSA is within the diagnostic gray zone. (authors)

Characteristics of particulate-bound polycyclic aromatic hydrocarbons emitted from industrial grade biomass boilers.

Science.gov (United States)

Yang, Xiaoyang; Geng, Chunmei; Sun, Xuesong; Yang, Wen; Wang, Xinhua; Chen, Jianhua

2016-02-01

Polycyclic aromatic hydrocarbons (PAHs) are carcinogenic or mutagenic and are important toxic pollutants in the flue gas of boilers. Two industrial grade biomass boilers were selected to investigate the characteristics of particulate-bound PAHs: one biomass boiler retro-fitted from an oil boiler (BB1) and one specially designed (BB2) biomass boiler. One coal-fired boiler was also selected for comparison. By using a dilution tunnel system, particulate samples from boilers were collected and 10 PAH species were analyzed by gas chromatography-mass spectrometry (GC-MS). The total emission factors (EFs) of PAHs ranged from 0.0064 to 0.0380 mg/kg, with an average of 0.0225 mg/kg, for the biomass boiler emission samples. The total PAH EFs for the tested coal-fired boiler were 1.8 times lower than the average value of the biomass boilers. The PAH diagnostic ratios for wood pellets and straw pellets were similar. The ratio of indeno(1,2,3-cd)pyrene/[indeno(1,2,3-cd)pyrene+benzo(g,h,i)perylene] for the two biomass boilers was lower than those of the reference data for other burning devices, which can probably be used as an indicator to distinguish the emission of biomass boilers from that of industrial coal-fired boilers and residential stoves. The toxic potential of the emission from wood pellet burning was higher than that from straw pellet burning, however both of them were much lower than residential stove exhausts. Copyright © 2015. Published by Elsevier B.V.

Source Apportionment of Particle Bound Polycyclic Aromatic Hydrocarbons at an Industrial Location in Agra, India

Directory of Open Access Journals (Sweden)

Anita Lakhani

2012-01-01

Full Text Available 16 US EPA priority polycyclic aromatic hydrocarbons (PAHs were quantified in total suspended ambient particulate matter (TSPM collected from an industrial site in Agra (India using gas chromatography. The major industrial activities in Agra are foundries that previously used coal and coke as fuel in cupola furnaces. These foundries have now switched over to natural gas. In addition, use of compressed natural gas has also been promoted and encouraged in automobiles. This study attempts to apportion sources of PAH in the ambient air and the results reflect the advantages associated with the change of fuel. The predominant PAHs in TSPM include high molecular weight (HMW congeners BghiP, DbA, IP, and BaP. The sum of 16 priority PAHs had a mean value of 72.7 ± 4.7 ng m−3. Potential sources of PAHs in aerosols were identified using diagnostic ratios and principal component analysis. The results reflect a blend of emissions from diesel and natural gas as the major sources of PAH in the city along with contribution from emission of coal, coke, and gasoline.

Novel techniques for characterization of hydrocarbon emission sources in the Barnett Shale

Science.gov (United States)

Nathan, Brian Joseph

Changes in ambient atmospheric hydrocarbon concentrations can have both short-term and long-term effects on the atmosphere and on human health. Thus, accurate characterization of emissions sources is critically important. The recent boom in shale gas production has led to an increase in hydrocarbon emissions from associated processes, though the exact extent is uncertain. As an original quantification technique, a model airplane equipped with a specially-designed, open-path methane sensor was flown multiple times over a natural gas compressor station in the Barnett Shale in October 2013. A linear optimization was introduced to a standard Gaussian plume model in an effort to determine the most probable emission rate coming from the station. This is shown to be a suitable approach given an ideal source with a single, central plume. Separately, an analysis was performed to characterize the nonmethane hydrocarbons in the Barnett during the same period. Starting with ambient hourly concentration measurements of forty-six hydrocarbon species, Lagrangian air parcel trajectories were implemented in a meteorological model to extend the resolution of these measurements and achieve domain-fillings of the region for the period of interest. A self-organizing map (a type of unsupervised classification) was then utilized to reduce the dimensionality of the total multivariate set of grids into characteristic one-dimensional signatures. By also introducing a self-organizing map classification of the contemporary wind measurements, the spatial hydrocarbon characterizations are analyzed for periods with similar wind conditions. The accuracy of the classification is verified through assessment of observed spatial mixing ratio enhancements of key species, through site-comparisons with a related long-term study, and through a random forest analysis (an ensemble learning method of supervised classification) to determine the most important species for defining key classes. The hydrocarbon

Kinetics of hydrocarbon extraction from oil shale using biosurfactant producing bacteria

International Nuclear Information System (INIS)

Haddadin, Malik S.Y.; Abou Arqoub, Ansam A.; Abu Reesh, Ibrahim; Haddadin, Jamal

2009-01-01

This study was done to extract hydrocarbon compounds from El-Lajjun oil shale using biosurfactant produced from two strains Rhodococcus erythropolis and Rhodococcus ruber. The results have shown that, optimal biosurfactant production was found using naphthalene and diesel as a carbon source for R. erthropolis and R. ruber, respectively. Optimum nitrogen concentration was 9 g/l and 7 g/l for R. erthropolis and R. ruber, respectively. Optimum K 2 HPO 4 to KH 2 PO 4 ratio, temperature, pH, and agitation speeds were 2:1, 37 deg. C, 7 and 200 rpm. Under optimal conditions R. erthropolis and R. ruber produced 5.67 and 6.9 g/l biosurfactant, respectively. Maximum recovery of oil achieved with hydrogen peroxide pre-treatment was 25% and 26% at biosurfactant concentration of 8 g/l and 4 g/l for R. erthropolis and R. ruber, respectively. The extent desorption of hydrocarbons from the pre-treated oil shale by biosurfactant were inversely related to the concentration of high molecular weight hydrocarbons, asphaltenes compounds. Pre- treatment of oil shale with hydrogen peroxide produced better improvement in aromatic compounds extraction in comparison with improvement which resulted from demineralization of the oil shale

Bioremediation of soils containing petroleum hydrocarbons, chlorinated phenols, and polycyclic aromatic hydrocarbons

International Nuclear Information System (INIS)

Seech, A.; Burwell, S.; Marvan, I.

1994-01-01

Bench-scale treatability investigations, pilot-scale and full-scale bioremediation projects were conducted to evaluate Daramend trademark bioremediation of soils containing petroleum hydrocarbons, heavy oils, paraffins, chlorinated phenols and polycyclic aromatic hydrocarbons (PAHs). Bench-scale investigations were conducted using glass microcosms. Pilot-scale and full-scale demonstrations were conducted at industrial sites and included treatment of excavated soils and sediments in on-site cells constructed using synthetic liners and covered by steel/polyethylene structures as well as in-situ treatment. A total of approximately 5,000 tons of soil was treated. The soil treatment included organic soil amendments, specialized tillage/aeration apparatus, and strict control of soil moisture. The amendments are composed of naturally-occurring organic materials prepared to soil-specific particle size distributions, nutrient profiles, and nutrient-release kinetics. Bench-scale work indicated that in refinery soil containing high concentrations of heavy oils, extractable hydrocarbon concentrations could be rapidly reduced to industrial clean-up criteria, and that the hydrocarbons were fully mineralized with release of CO 2

Comparing diagnostic tests on benefit-risk.

Science.gov (United States)

Pennello, Gene; Pantoja-Galicia, Norberto; Evans, Scott

2016-01-01

Comparing diagnostic tests on accuracy alone can be inconclusive. For example, a test may have better sensitivity than another test yet worse specificity. Comparing tests on benefit risk may be more conclusive because clinical consequences of diagnostic error are considered. For benefit-risk evaluation, we propose diagnostic yield, the expected distribution of subjects with true positive, false positive, true negative, and false negative test results in a hypothetical population. We construct a table of diagnostic yield that includes the number of false positive subjects experiencing adverse consequences from unnecessary work-up. We then develop a decision theory for evaluating tests. The theory provides additional interpretation to quantities in the diagnostic yield table. It also indicates that the expected utility of a test relative to a perfect test is a weighted accuracy measure, the average of sensitivity and specificity weighted for prevalence and relative importance of false positive and false negative testing errors, also interpretable as the cost-benefit ratio of treating non-diseased and diseased subjects. We propose plots of diagnostic yield, weighted accuracy, and relative net benefit of tests as functions of prevalence or cost-benefit ratio. Concepts are illustrated with hypothetical screening tests for colorectal cancer with test positive subjects being referred to colonoscopy.

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.

Distribution and Fractional Composition of Petroleum Hydrocarbons in Roadside Soils

Directory of Open Access Journals (Sweden)

Larysa Mykhailova

2013-01-01

Full Text Available Total petroleum hydrocarbon (TPH concentrations and their fractional composition (medium fraction: n-alkane chain-length C15 to C27, heavy fraction: >C27 were determined at distances from 1 to 60 m from roads and at soil depths from 0.5 to 15 cm. The traffic intensities were up to 25000 vehicles per day. Soil TPH concentrations were highest within 15 m distance (665 and 3198 mg kg−1 at the windward and leeward sides, resp., followed by a rapid drop to background values beyond (196 and 115 mg kg−1 in 60 m distance at the windward and leeward sides, resp.. The data variability was lowest at distances of 1 m and highest within tree plantations at distances of 15 m from the road. The TPH concentrations decreased with depth but were significantly higher than the background at all depths investigated. A principal component analysis revealed a positive relation between the medium-to-heavy fraction ratio and soil depth. A fractional differentiation of hydrocarbons with distance from road was not observed. It was concluded that the assessment of the potential of hydrocarbons to translocate, accumulate, or degrade in soil necessitates their subdivision into fractions based on their physicochemical and metabolic properties.

The diagnostic value of pleural effusion ferritin and the ratio of it to serum ferritin in differentiating exudates from transudates

International Nuclear Information System (INIS)

Yang Liu; Liu Junfeng; Yu Jiuru; Ju Ping; Ke Caiming

2003-01-01

To explore the diagnostic value of measuring the level of ferritin in pleural and peritoneal effusion for differentiating exudates from transudates, 128 effusion samples were initially detected for differentiating exudates from transudates by traditional method and Light's criteria. Ferritin in the effusions and serum ferritin were detected simultaneously, and the ratio of effusion ferritin (P Ft ) to serum ferritin (S Ft ) was counted. Based on the clinical data, the samples were divided into four groups and P Ft and P Ft /S Ft were compared. At the same time, the sensitivity and specificity of P Ft and P Ft /S Ft in differentiating exudates from transudates were compared with traditional method and Light's criteria. The results showed that in the groups of tuberculous pleurisy, non-tuberculous, benign pleurisy, and malignant tumor, the concentration of Ft in the effusions was significantly higher than that in the group of congestive heart failure and cirrhosis; and the Ft in exudates was significantly higher than that in transudates (P 0.05). If the cut-off value was set up for Ft in the effusion as 100 μg/L and P Ft /S Ft ratio as 0.5, respectively, the differentiating sensitivity and specificity were 94.2% and 87.0%, respectively. Conclusion was that the concentration of P Ft and P Ft /S Ft in exudates are higher than 100 μg/L and 0.5, respectively. On the contrary, they are lower than the cut-off level in transudates. P Ft and P Ft /S Ft have high sensitivity and high specificity in differentiating exudates from transudates, and have great diagnostic value

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.

Measurement of the C / H ratio using neutrons; Mesure du rapport C / H au moyen des neutrons

Energy Technology Data Exchange (ETDEWEB)

Martinelli, P [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires; Ricci, H [Universite de Lima (Peru)

1960-07-01

A probe made up of a Ra ({alpha}, n) Be neutron source and a proportional counter filled with boron trifluoride has been used to measure the C/H ratio in hydrocarbons. The intensity of the thermal neutron flux in the neighbourhood of the detector increases with the concentration of the hydrocarbon hydrogen surrounding it. By measuring the density it is possible to deduce the C/H ratio. It is thus possible to evaluate the C/H ratio with a precision equal to that given by the {beta}-ray transmission method. The errors arising from the chemical nature of the hydrocarbon can be reduced to a minimum. This method has the advantage of allowing the measurement of the C/H ratio of hydrocarbons contained in recipients or thick steel tubing by means an independent portable apparatus. (author) [French] Une sonde constituee d'une source de neutrons Ra ({alpha}, n) Be et d'un compteur proportionnel a remplissage de trifluorure de bore a ete utilisee pour mesurer le rapport C/H dans les hydrocarbures. Le flux des neutrons thermiques au voisinage du detecteur est d'autant plus intense que la concentration en hydrogene de l'hydrocarbure qui entoure la sonde est plus elevee. Une mesure de densite permet d'en deduire le rapport C/H. On peut ainsi evaluer le rapport C/H avec une precision aussi bonne que celle que l'on obtient par transmission de rayons {beta}. Les erreurs provenant de la nature chimique de l'hydrocarbure peuvent etre minimisees. Cette methode presente l'avantage de permettre la mesure du rapport C/H d'hydrocarbures contenus dans des recipients ou des canalisations epaisses en acier a l'aide d'un appareil exterieur transportable. (auteur)

Method and apparatus for synthesizing hydrocarbons

Science.gov (United States)

Colmenares, C.A.; Somorjai, G.A.; Maj, J.J.

1985-04-16

A method and apparatus for synthesizing a mixture of aliphatic alcohols having five carbons or less is disclosed. An equal molar ratio of CO and H/sub 2/ gases is caused to pass through a ThO/sub 2/ catalyst having a surface area of about 80 to 125 m/sup 2//g. The catalyst further optionally includes Na ions present as substitutional cations in an amount of about 5 to 10 atom %. At a temperature of about 570 to 630/sup 0/K, and at pressures of about 20 to 50 atm, methanol and isobutanol are the predominant products and are produced in amounts of about 90 wt % of the total hydrocarbon mixture. 6 figs.

Non-methane hydrocarbons in a controlled ecological life support system.

Science.gov (United States)

Dai, Kun; Yu, Qingni; Zhang, Zhou; Wang, Yuan; Wang, Xinming

2018-02-01

Non-methane hydrocarbons (NMHCs) are vital to people's health and plants' growth, especially inside a controlled ecological life support system (CELSS) built for long-term space explorations. In this study, we measured 54 kinds of NMHCs to study their changing trends in concentration levels during a 4-person-180-day integrated experiment inside a CELSS with four cabins for plants growing and other two cabins for human daily activities and resources management. During the experiment, the total mixing ratio of measured NMHCs was 423 ± 283 ppbv at the first day and it approached 2961 ± 323 ppbv ultimately. Ethane and propane were the most abundant alkanes and their mixing ratios kept growing from 27.5 ± 19.4 and 31.0 ± 33.6 ppbv to 2423 ± 449 ppbv and 290 ± 10 ppbv in the end. For alkenes, ethylene and isoprene presented continuously fluctuating states during the experimental period with average mixing ratios of 30.4 ± 19.3 ppbv, 7.4 ± 5.8 ppbv. For aromatic hydrocarbons, the total mixing ratios of benzene, toluene, ethylbenzene and xylenes declined from 48.0 ± 44 ppbv initially to 3.8 ± 1.1 ppbv ultimately. Biomass burning, sewage treatment, construction materials and plants all contributed to NMHCs inside CELSS. In conclusion, the results demonstrate the changing trends of NMHCs in a long-term closed ecological environment's atmosphere which provides valuable information for both the atmosphere management of CELSS and the exploration of interactions between humans and the total environment. Copyright © 2017 Elsevier Ltd. All rights reserved.

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.

Gamma ray spectrometry logs as a hydrocarbon indicator for clastic reservoir rocks in Egypt.

Science.gov (United States)

Al-Alfy, I M; Nabih, M A; Eysa, E A

2013-03-01

Petroleum oil is an important source for the energy in the world. The Gulf of Suez, Nile Delta and South Valley are important regions for studying hydrocarbon potential in Egypt. A thorium normalization technique was applied on the sandstone reservoirs in the three regions to determine the hydrocarbon potentialities zones using the three spectrometric radioactive gamma ray-logs (eU, eTh and K% logs). The conventional well logs (gamma-ray, deep resistivity, shallow resistivity, neutron, density and sonic logs) are analyzed to determine the net pay zones in these wells. Indices derived from thorium normalized spectral logs indicate the hydrocarbon zones in petroleum reservoirs. The results of this technique in the three regions (Gulf of Suez, Nile Delta and South Valley) are in agreement with the results of the conventional well log analyses by ratios of 82%, 78% and 71% respectively. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

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)

Hydrous pyrolysis/oxidation process for in situ destruction of chlorinated hydrocarbon and fuel hydrocarbon contaminants in water and soil

Science.gov (United States)

Knauss, Kevin G.; Copenhaver, Sally C.; Aines, Roger D.

2000-01-01

In situ hydrous pyrolysis/oxidation process is useful for in situ degradation of hydrocarbon water and soil contaminants. Fuel hydrocarbons, chlorinated hydrocarbons, polycyclic aromatic hydrocarbons, petroleum distillates and other organic contaminants present in the soil and water are degraded by the process involving hydrous pyrolysis/oxidation into non-toxic products of the degradation. The process uses heat which is distributed through soils and water, optionally combined with oxygen and/or hydrocarbon degradation catalysts, and is particularly useful for remediation of solvent, fuel or other industrially contaminated sites.

Experimental investigation of hydrocarbon mixtures to replace HFC-134a in an automotive air conditioning system

International Nuclear Information System (INIS)

Wongwises, Somchai; Kamboon, Amnouy; Orachon, Banchob

2006-01-01

This paper presents an experimental study on the application of hydrocarbon mixtures to replace HFC-134a in automotive air conditioners. The hydrocarbons investigated are propane (R290), butane (R600) and isobutane (R600a). The measured data are obtained from an automotive air conditioning test facility utilizing HFC-134a as the refrigerant. The air conditioner, with a capacity of 3.5 kW driven by a Diesel engine, is charged and tested with four different ratios of hydrocarbon mixtures. The experiments are conducted at the same surrounding conditions. The temperature and pressure of the refrigerant at every major position in the refrigerant loop, the temperature, flow rate and humidity of air, torque and engine speed are recorded and analyzed. The parameters investigated are the refrigeration capacity, the compressor power and the coefficient of performance (COP). The results show that propane/butane/isobutane: 50%/40%/10% is the most appropriate alternative refrigerant to replace HFC-134a, having the best performance of all the hydrocarbon mixtures investigated

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.

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

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.

Reassessment of the hydrocarbons in Prince William Sound and the Gulf of Alaska : identifying the source using partial least squares

International Nuclear Information System (INIS)

Mudge, S.M.

2001-01-01

Since the Exxon Valdez oil spill in Prince William Sound, Alaska there has been much discussion regarding the clean-up and long term fate of the oil. There has also been debate regarding the origin of the background hydrocarbons present within Prince William Sound (PWS) and the Gulf of Alaska (GoA). There is evidence that background (pre-spill) hydrocarbons may come from either nearby coal deposits or from natural oil seeps and eroding source rocks in the region. This paper presented a study in which the multivariate statistical methodology of the Partial Least Squares (PLS) was used to reassess the percentage contribution of coal, seep oil, shales and rivers to the hydrocarbon loading in the GoA. Data was provided by researchers at the National Ocean and Atmospheric Administration (NOAA) and the Bowdoin College, for Exxon. The data was analysed using selected sites as sources in order to develop signatures. The signatures were based on 40 and 136 compounds respectively, including the polyaromatic hydrocarbon (PAH) and terpane biomarkers from the Exxon data. The key components describing the sources were fitted to the data for other sites around the GoA to determine the proportion of the variability described by each source. The large complex datasets can be used to develop complex fingerprints for sources rather than using relatively simplistic ratios between selected compounds. The results indicate that 30 per cent of the signature is common between each source and that the small PAHs are the best diagnostic compounds in the model for the oil signature and the large PAHs are good for coal. Naphthalene, methyl and dimethyl naphthalene are the best markers for the seep oil signature. For the pre-spill background, coals and shales are best defined by the larger PAHs such as perylene and benzo(ghi)perylene. In general, the average partitioning between the two sources across all the sampling sites within the region indicated that 53 per cent is attributable to the

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.

Diagnostic value of multiple tumor markers for patients with esophageal carcinoma.

Science.gov (United States)

Zhang, Jun; Zhu, Zhenli; Liu, Yan; Jin, Xueyuan; Xu, Zhiwei; Yu, Qiuyan; Li, Ke

2015-01-01

Various studies assessing the diagnostic value of serum tumor markers in patients with esophageal cancer remain controversial. This study aims to comprehensively and quantitatively summarize the potential diagnostic value of 5 serum tumour markers in esophageal cancer. We systematically searched PubMed, Embase, Chinese National Knowledge Infrastructure (CNKI) and Chinese Biomedical Database (CBM), through February 28, 2013, without language restriction. Studies were assessed for quality using QUADAS (quality assessment of studies of diagnostic accuracy). The positive likelihood ratio (PLR) and negative likelihood ratio (NLR) were pooled separately and compared with overall accuracy measures using diagnostic odds ratios (DORs) and symmetric summary receiver operating characteristic (SROC) curves. Of 4391 studies initially identified, 44 eligible studies including five tumor markers met the inclusion criteria for the meta-analysis, while meta-analysis could not be conducted for 12 other tumor markers. Approximately 79.55% (35/44) of the included studies were of relatively high quality (QUADAS score≥7). The summary estimates of the positive likelihood ratio (PLR), negative likelihood ratio (NLR) and diagnostic odds ratio (DOR) for diagnosing EC were as follows: CEA, 5.94/0.76/9.26; Cyfra21-1, 12.110.59/22.27; p53 antibody, 6.71/0.75/9.60; SCC-Ag, 7.66/0.68/12.41; and VEGF-C, 0.74/0.37/8.12. The estimated summary receiver operating characteristic curves showed that the performance of all five tumor markers was reasonable. The current evidence suggests that CEA, Cyfra21-1, p53, SCC-Ag and VEGF-C have a potential diagnostic value for esophageal carcinoma.

Petroleum hydrocarbons in sediment from the northern Gulf of Mexico shoreline, Texas to Florida

Science.gov (United States)

Rosenbauer, Robert J.; Campbell, Pamela L.; Lam, Angela; Lorenson, T.D.; Hostettler, Frances D.; Thomas, Burt; Wong, Florence L.

2011-01-01

Petroleum hydrocarbons were extracted and analyzed from shoreline sediment collected from the northern Gulf of Mexico (nGOM) coastline that could potentially be impacted by Macondo-1 (M-1) well oil. Sediment was collected before M-1 well oil made significant local landfall and analyzed for baseline conditions by a suite of diagnostic petroleum biomarkers. Oil residue in trace quantities was detected in 45 of 69 samples. With the aid of multivariate statistical analysis, three different oil groups, based on biomarker similarity, were identified that were distributed geographically along the nGOM from Texas to Florida. None of the sediment hydrocarbon extracts correlated with the M-1 well oil extract, however, the similarity of tarballs collected at one site (FL-18) with the M-1 well oil suggests that some oil from the Deepwater Horizon spill may have been transported to this site in the Florida Keys, perhaps by a loop current, before that site was sampled.

Effect of hydrocarbon chain length of aliphatic diluents on hydrodynamic properties of irradiated solutions of extractant

International Nuclear Information System (INIS)

Gumenyuk, V.E.; Pribush, A.G.; Egorov, G.F.

1990-01-01

To optimize the composition of n-paraffin mixtures with different molecular weight, used as a diluent (D) of extractant during extraction reprocessing of spent fuel, interrelation between D hydrocarbon chain length and change in hydrodynamic properties of extraction mixture on D basis depending on the dose has been considered. It is shown that the value of threshold dose loading (D crit ), at which a sharp change in hydrodynamic properties of tri-n-butyl phosphate solutions in D is observed, decreases with hydrocarbon chain length growth. Empiric ratio relating D crit value and the number of carbon atoms of D is obtained

Aliphatic hydrocarbon and polycyclic aromatic hydrocarbon geochemistry of twelve major rivers in the Northwest Territories

International Nuclear Information System (INIS)

Backus, S.; Swyripa, M.; Peddle, J.; Jeffries, D.S.

1995-01-01

Suspended sediment and water samples collected from twelve major rivers in the Northwest Territories were analyzed for aliphatic hydrocarbons and polycyclic aromatic hydrocarbons (PAHs) to assess the sources and transport of hydrocarbons entering the Arctic Ocean. Three stations on the Mackenzie River and one station near the mouth of eleven other northern rivers were selected for sampling. Samples were collected on the Mackenzie River on four occasions to characterize spring, summer and fall flow conditions and once on the remaining eleven rivers during high flow conditions. The Mackenzie River is distinctively different then the other eleven rivers. Naturally occurring hydrocarbons predominate in the river. These hydrocarbons include biogenic alkanes, diagenic PAHs, petrogenic alkanes, and PAHs from oil seeps and/or bitumens. Anthropogenic inputs of PAHs are low as indicated by low concentrations of combustion PAHs. Alkyl PAH distributions indicate that a significant component of the lower molecular weight PAH fraction is petrogenic. The majority of the high molecular weight PAHs, together with the petrogenic PAHs have a principal source in the Mackenzie River

Molecular dynamics simulation of chemical vapor deposition of amorphous carbon. Dependence on H/C ratio of source gas

International Nuclear Information System (INIS)

Ito, Atsushi M.; Takayama, Arimichi; Nakamura, Hiroaki; Saito, Seiki; Ohno, Noriyasu; Kajita, Shin

2011-01-01

By molecular dynamics simulation, the chemical vapor deposition of amorphous carbon onto graphite and diamond surfaces was studied. In particular, we investigated the effect of source H/C ratio, which is the ratio of the number of hydrogen atoms to the number of carbon atoms in a source gas, on the deposition process. In the present simulation, the following two source gas conditions were tested: one was that the source gas was injected as isolated carbon and hydrogen atoms, and the other was that the source gas was injected as hydrocarbon molecules. Under the former condition, we found that as the source H/C ratio increases, the deposition rate of carbon atoms decreases exponentially. This exponential decrease in the deposition rate with increasing source H/C ratio agrees with experimental data. However, under the latter molecular source condition, the deposition rate did not decrease exponentially because of a chemical reaction peculiar to the type of hydrocarbon in the source gas. (author)

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.

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.

Zn-Mo/HZSM-5 Catalyst for Gasoil Range Hydrocarbon Production by Catalytic Hydrocracking of Ceiba pentandra oil

Directory of Open Access Journals (Sweden)

Yustia Wulandari Mirzayanti

2018-01-01

Full Text Available Biofuel from vegetable oil becomes one of the most suitable and logical alternatives to replace fossil fuel. The research focused on various metal ratio Zinc/Molybdenum/HZSM-5 (Zn-Mo/HZSM-5 catalyst to produce liquid hydrocarbon via catalytic hydrocracking of Ceiba penandra oil. The catalytic hydrocracking process has been applied in this study to crack Ceiba pentandra oil into a gasoil range hydrocarbon using Zn-Mo/HZSM-5 as a catalyst. The effect of various reaction temperature on the catalytic hydrocracking of Ceiba pentandra oil were studied. The Zn-Mo/HZSM-5 catalyst with metal ratio was prepared by incipient wetness impregnation method. This process used slurry pressure batch reactor with a mechanical stirrer. A series of experiments were carried out in the temperature range from 300-400 oC for 2 h at pressure between 10-15 bar. The conversion and selectivity were estimated. The liquid hydrocarbon product were identified to gasoline, kerosene, and gas oil. The results show that the use of Zn-Mo/HZSM-5 can produce gas oil as the most component in the product. Overall, the highest conversion and selectivity of gas oil range hydrocarbon was obtained when the ZnMo/HZSM-5 metal ratio was Zn(2.86 wt.%-Mo(5.32 wt.%/HZSM-5 and the name is Zn-Mo/HZSM-5_102. The highest conversion was obtained at 63.31 % and n-paraffin (gas oil range selectivity was obtained at 90.75 % at a temperature of 400 oC. Ceiba pentandra oil can be recommended as the source of inedible vegetable oil to produce gasoil as an environmentally friendly transportation fuel. Copyright © 2018 BCREC Group. All rights reserved Received: 8th September 2017; Revised: 9th September 2017; Accepted: 17th September 2017; Available online: 22nd January 2018; Published regularly: 2nd April 2018 How to Cite: Mirzayanti, Y.W., Kurniawansyah, F., Prajitno, D.H., Roesyadi, A. (2018. Zn-Mo/HZSM-5 Catalyst for Gasoil Range Hydrocarbon Production by Catalytic Hydrocracking of Ceiba pentandra

Polycyclic aromatic hydrocarbons in urban soil of Novi Sad, Serbia: occurrence and cancer risk assessment.

Science.gov (United States)

Škrbić, Biljana D; Đurišić-Mladenović, Nataša; Tadić, Đorđe J; Cvejanov, Jelena Đ

2017-07-01

Contents of 16 polycyclic aromatic hydrocarbons were analyzed in 30 soil samples from 15 locations in Novi Sad, Serbia, assessing for the first time the corresponding health risks in the Serbian urban zone. Total concentrations were in the range of 22-2247 μg kg -1 , with a mean and median value of 363 and 200 μg kg -1 , respectively. Comparison with the relevant maximum allowed contents proposed by the Serbian government and with the Dutch target values implied that soils from the urban area of Novi Sad were "suitable as residential soils" and that no intervention would be needed if the current levels were retained. Seven diagnostic ratios were calculated, indicating the pyrogenic sources of PAHs as the dominant. Cancer risks in humans via accidental ingestion, inhalation of soil particles, and dermal contact with soil were estimated. Cancer risk for soil ingestion by children was the highest. The total lifetime carcinogenic risk as sum of individual cancer risks for seven carcinogenic polycyclic aromatic hydrocarbons was within the range 10 -4 to 10 -6 , indicating acceptable risks at 30 and 47% of sites for children and adults, respectively. However, for the rest of the samples, total lifetime cancer risk was >10 -4 indicating over the acceptable risk, even though the contents in soil were not of concern as the comparison with the environmental guidance previously showed. This could be explained by (a) the dominant concentrations of higher molecular weight compounds with 4 to 6 rings, among which there are compounds with higher toxicity equivalents, but also with (b) the extreme conditions used for the conservative risk assessment under maximal exposure frequency, exposure time, and ingestion rates.

Filtered x-ray diode diagnostics fielded on the Z-accelerator for source power measurements

International Nuclear Information System (INIS)

Chandler, G.A.; Deeney, C.; Cuneo, M.

1998-01-01

Filtered x-ray diode, (XRD), detectors are used as primary radiation flux diagnostics on Sandia's Z-accelerator, which generates nominally a 200 TW, 2 MJ, x-ray pulse. Given such flux levels and XRD sensitivities the detectors are being fielded 23 meters from the source. The standard diagnostic setup and sensitivities are discussed. Vitreous carbon photocathodes are being used to reduce the effect of hydrocarbon contamination present in the Z-machine vacuum system. Nevertheless pre- and post-calibration data taken indicate spectrally dependent changes in the sensitivity of these detectors by up to factors up to 2 or 3

Methodology of diagnostic tests in hepatology

DEFF Research Database (Denmark)

Christensen, Erik

2009-01-01

The performance of diagnostic tests can be assessed by a number of methods. These include sensitivity, specificity,positive and negative predictive values, likelihood ratios and receiver operating characteristic (ROC) curves. This paper describes the methods and explains which information...... they provide. Sensitivity and specificity provides measures of the diagnostic accuracy of a test in diagnosing the condition. The positive and negative predictive values estimate the probability of the condition from the test-outcome and the condition's prevalence. The likelihood ratios bring together......' and plotting sensitivity as a function of 1-specificity. The ROC-curve can be used to define optimal cut-off values for a test, to assess the diagnostic accuracy of the test, and to compare the usefulness of different tests in the same patients. Under certain conditions it may be possible to utilize a test...

Advantages of the nested case-control design in diagnostic research

Directory of Open Access Journals (Sweden)

Hoes Arno W

2008-07-01

Full Text Available Abstract Background Despite its benefits, it is uncommon to apply the nested case-control design in diagnostic research. We aim to show advantages of this design for diagnostic accuracy studies. Methods We used data from a full cross-sectional diagnostic study comprising a cohort of 1295 consecutive patients who were selected on their suspicion of having deep vein thrombosis (DVT. We draw nested case-control samples from the full study population with case:control ratios of 1:1, 1:2, 1:3 and 1:4 (per ratio 100 samples were taken. We calculated diagnostic accuracy estimates for two tests that are used to detect DVT in clinical practice. Results Estimates of diagnostic accuracy in the nested case-control samples were very similar to those in the full study population. For example, for each case:control ratio, the positive predictive value of the D-dimer test was 0.30 in the full study population and 0.30 in the nested case-control samples (median of the 100 samples. As expected, variability of the estimates decreased with increasing sample size. Conclusion Our findings support the view that the nested case-control study is a valid and efficient design for diagnostic studies and should also be (reappraised in current guidelines on diagnostic accuracy research.

Low-maturity Kulthieth Formation coal: A possible source of polycyclic aromatic hydrocarbons in benthic sediment of the northern Gulf of Alaska

Science.gov (United States)

Van Kooten, G. K.; Short, J.W.; Kolak, J.J.

2002-01-01

The successful application of forensic geology to contamination studies involving natural systems requires identification of appropriate endmembers and an understanding of the geologic setting and processes affecting the systems. Studies attempting to delineate the background, or natural, source for hydrocarbon contamination in Gulf of Alaska (GOA) benthic sediments have invoked a number of potential sources, including seep oils, source rocks, and coal. Oil seeps have subsequently been questioned as significant sources of hydrocarbons present in benthic sediments of the GOA in part because the pattern of relative polycyclic aromatic hydrocarbon (PAH) abundance characteristic of benthic GOA sediments is inconsistent with patterns typical of weathered seep oils. Likewise, native coal has been dismissed in part because ratios of labile hydrocarbons to total organic carbon (e.g. PAH:TOC) for Bering River coal field (BRCF) sources are too low - i.e. the coals are over mature - to be consistent with GOA sediments. We present evidence here that native coal may have been prematurely dismissed, because BRCF coals do not adequately represent the geochemical signatures of coals elsewhere in the Kulthieth Formation. Contrary to previous thought, Kulthieth Formation coals east of the BRCF have much higher PAH: TOC ratios, and the patterns of labile hydrocarbons in these low thermal maturity coals suggest a possible genetic relationship between Kulthieth Formation coals and nearby oil seeps on the Sullivan anticline. Analyses of low-maturity Kulthieth Formation coal indicate the low maturity coal is a significant source of PAH. Source apportionment models that neglect this source will underestimate the contribution of native coals to the regional background hydrocarbon signature. ?? Published by Elsevier Science Ltd. on behalf of AEHS.

Characterization of polycyclic aromatic hydrocarbons in fog-rain events.

Science.gov (United States)

Li, Xiang; Li, Pengfei; Yan, Lili; Chen, Jianmin; Cheng, Tiantao; Xu, Shifen

2011-11-01

Atmospheric polycyclic aromatic hydrocarbons (PAHs) mainly originate from incomplete combustion or pyrolysis of materials containing carbon and hydrogen. They exist in gas and particle phases, as well as dissolved or suspended in precipitation (fog or rain). Current studies in atmospheric PAHs are predominantly focused on fog and rainwater samples. Some sampling difficulties are associated with fog samples. This study presented the first observation of the characteristics of PAHs in fog samples using a solid phase microextraction (SPME) technique. Eighteen fog samples were collected during ten fog events from March to December 2009 in the Shanghai area. PAHs were extracted by SPME and analyzed by gas chromatography-mass spectrometry (GC-MS). As the compounds were partially soluble in water, with solubility decreasing with increasing molecular weight, low molecular weight (LMW) PAH compounds were universally found in the fog water samples. Naphthalene (NaP), phenanthrene (Phe), anthracene (Ant) and fluoranthene (Flo) were dominant compounds in fog water. The total PAH concentration in fog water ranged from 0.03 to 6.67 μg L(-1) (mean of 1.06 μg L(-1)), and was much higher in winter than in summer. The concentration of PAHs in fog or rain water decreased after undergoing a pre-rain or pre-fog wash. The average concentration of PAHs was higher in fog than in rain. Diagnostic ratio analysis suggested that petroleum and combustion were the dominant contributors to PAHs in urban Shanghai. Backward trajectories were calculated to determine the origin of the air masses, showing that air masses were mostly from the northeast territory.

Advanced oxygen-hydrocarbon Earth-to-orbit propulsion

Science.gov (United States)

Obrien, C. J.

1981-01-01

Liquid oxygen/hydrocarbon (LO2/HC) rocket engine cycles for a surface to orbit transportation system were evaluated. A consistent engine system data base is established for defining advantages and disadvantages, system performance and operating limits, engine parametric data, and technology requirements for candidate engine systems. Preliminary comparisons of the engine cycles utilizing delivered specific impulse values are presented. Methane and propane staged combustion cycles are the highest LO2/HC performers. The hydrogen cooled LO2/methane dual throat engine was found to be the highest performing. Technology needs identified in the study include: high temperature turbines; oxidizer-rich preburners; LO2, methane, and propane cooling; methane and propane fuel-rich preburners; the HC fuel turbopump; and application of advanced composite materials to the engine system. Parametric sensitivity analysis data are displayed which show the effect of variations in engine thrust, mixture ratio, chamber pressure, area ratio, cycle life, and turbine inlet temperature on specific impulse and engine weight.

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.

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.

Coronal temperature diagnostics from high-resolution soft X-ray spectra

Science.gov (United States)

Strong, K. T.; Claflin, E. S.; Lemen, J. R.; Linford, G. A.

1988-01-01

The problem of deriving the temperature of the coronal plasma from soft X-ray spectra is discussed. Spectral atlas scans of the soft X-ray spectrum from the Flat Crystal Spectrometer on the Solar Maximum Mission are compared with theoretical predictions of the relative intensities of some of the brighter lines to determine which line intensity ratios give the most reliable temperature diagnostics. The techniques considered include line widths, He-like G ratios, intensity ratios, and ratios of lines formed by different elements. It is found that the best temperature diagnostics come from the ratios of lines formed by successive ionization stages of the same element.

Long range transport of hydrocarbons in the Southern Ocean

International Nuclear Information System (INIS)

Pinturier, L.; Leureillard, J.; Arnold, M.; Tisnerat, N.; Pichon, J.J.; Gireaudau, J.

1999-01-01

We report here the first results for hydrocarbon analyses of deep surface sediments collected in the Indian sector of the Southern Ocean. The samples were taken along a north-south transect ranging from 43 deg. S to 55 deg. S in the southwestern Crozet Basin. In order to identify these compounds and elucidate their origins, various techniques were used: gas chromatography and gas chromatography coupled with mass spectrometry; Accelerator Mass Spectrometry (Tandetron: mass spectrometer coupled with a Tandem accelerator allowing the measure of 14 C/ 12 C ratio)

Kinetics of hydrocarbon extraction from oil shale using biosurfactant producing bacteria

Energy Technology Data Exchange (ETDEWEB)

Haddadin, Malik S.Y.; Abou Arqoub, Ansam A.; Abu Reesh, Ibrahim [Faculty of Graduate Studies, Jordan University, Queen Rania Street, Amman, 11942 (Jordan); Haddadin, Jamal [Faculty of Agriculture, Mutah University, P.O. Box 59, Mutah 61710 (Jordan)

2009-04-15

This study was done to extract hydrocarbon compounds from El-Lajjun oil shale using biosurfactant produced from two strains Rhodococcus erythropolis and Rhodococcus ruber. The results have shown that, optimal biosurfactant production was found using naphthalene and diesel as a carbon source for R. erthropolis and R. ruber, respectively. Optimum nitrogen concentration was 9 g/l and 7 g/l for R. erthropolis and R. ruber, respectively. Optimum K{sub 2}HPO{sub 4} to KH{sub 2}PO{sub 4} ratio, temperature, pH, and agitation speeds were 2:1, 37 C, 7 and 200 rpm. Under optimal conditions R. erthropolis and R. ruber produced 5.67 and 6.9 g/l biosurfactant, respectively. Maximum recovery of oil achieved with hydrogen peroxide pre-treatment was 25% and 26% at biosurfactant concentration of 8 g/l and 4 g/l for R. erthropolis and R. ruber, respectively. The extent desorption of hydrocarbons from the pre-treated oil shale by biosurfactant were inversely related to the concentration of high molecular weight hydrocarbons, asphaltenes compounds. Pre-treatment of oil shale with hydrogen peroxide produced better improvement in aromatic compounds extraction in comparison with improvement which resulted from demineralization of the oil shale. (author)

Investigation of Factors Influencing Dispersion of Liquid Hydrocarbons in Porous Media

Directory of Open Access Journals (Sweden)

Hussain Ali Baker

2016-08-01

Full Text Available An experimental work has been done to study the major factors that affect the axial dispersion of some hydrocarbons during liquid-liquid miscible displacement. Kerosene and gas oil are used as displacing phase while seven liquid hydrocarbons of high purity represent the displaced phase, three of the liquids are aromatics and the rest are of paraffinic base. In conducting the experiments, two packed beds of different porosity and permeability are used as porous media. The results showed that the displacement process is not a piston flow, breakthrough of displacing fluids are shown before one pore volume has been injected. The processes are stable with no evidence of viscous fingering. Dispersion model as adapted by Brigham et.al (1961 is used to determine the axial dispersion coefficient of displacing fluid. The results show an increasing in dispersion coefficient as the interstitial velocity and viscosity ratio increases.

Galaxy emission line classification using three-dimensional line ratio diagrams

Energy Technology Data Exchange (ETDEWEB)

Vogt, Frédéric P. A.; Dopita, Michael A.; Kewley, Lisa J.; Sutherland, Ralph S. [Research School of Astronomy and Astrophysics, Australian National University, Canberra, ACT 2611 (Australia); Scharwächter, Julia [Observatoire de Paris, LERMA (CNRS: UMR8112), 61 Av. de l' Observatoire, F-75014 Paris (France); Basurah, Hassan M.; Ali, Alaa; Amer, Morsi A., E-mail: frederic.vogt@anu.edu.au [Astronomy Department, King Abdulaziz University, P.O. Box 80203, Jeddah (Saudi Arabia)

2014-10-01

Two-dimensional (2D) line ratio diagnostic diagrams have become a key tool in understanding the excitation mechanisms of galaxies. The curves used to separate the different regions—H II-like or excited by an active galactic nucleus (AGN)—have been refined over time but the core technique has not evolved significantly. However, the classification of galaxies based on their emission line ratios really is a multi-dimensional problem. Here we exploit recent software developments to explore the potential of three-dimensional (3D) line ratio diagnostic diagrams. We introduce the ZQE diagrams, which are a specific set of 3D diagrams that separate the oxygen abundance and the ionization parameter of H II region-like spectra and also enable us to probe the excitation mechanism of the gas. By examining these new 3D spaces interactively, we define the ZE diagnostics, a new set of 2D diagnostics that can provide the metallicity of objects excited by hot young stars and that cleanly separate H II region-like objects from the different classes of AGNs. We show that these ZE diagnostics are consistent with the key log [N II]/Hα versus log [O III]/Hβ diagnostic currently used by the community. They also have the advantage of attaching a probability that a given object belongs to one class or the other. Finally, we discuss briefly why ZQE diagrams can provide a new way to differentiate and study the different classes of AGNs in anticipation of a dedicated follow-up study.

Syngas Conversion to Gasoline-Range Hydrocarbons over Pd/ZnO/Al2O3 and ZSM-5 Composite Catalyst System

Energy Technology Data Exchange (ETDEWEB)

Dagle, Robert A.; Lizarazo Adarme, Jair A.; Lebarbier, Vanessa MC; Gray, Michel J.; White, James F.; King, David L.; Palo, Daniel R.

2014-07-01

A composite Pd/ZnO/Al2O3-HZSM-5 (Si/Al=40) catalytic system was evaluated for the synthesis of gasoline-range hydrocarbons directly from synthesis gas. Bifunctional catalyst comprising PdZn metal and acid sites present the required catalytically active sites necessary for the methanol synthesis, methanol dehydration, and methanol-to-gasoline reactions. This system provides a unique catalytic pathway for the production of liquid hydrocarbons directly from syngas. However, selectivity control is difficult and poses many challenges. The composite catalytic system was evaluated under various process conditions. Investigated were the effects of temperature (310-375oC), pressure (300-1000 psig), time-on-stream (50 hrs), and gas-hour space velocity (740-2970 hr-1), using a H2/CO molar syngas ratio of 2.0. By operating at the lower end of the temperature range investigated, liquid hydrocarbon formation was favored, as was decreased amounts of undesirable light hydrocarbons. However, lower operating temperatures also facilitated undesirable CO2 formation via the water-gas shift reaction. Higher operating pressures slightly favored liquid synthesis. Operating at relatively low pressures (e.g. 300 psig) was made possible, whereas for methanol synthesis alone higher pressure are usually required to achieve similar conversion levels (e.g. 1000 psig). Thermodynamic constraints on methanol synthesis are eased by pushing the equilibrium through hydrocarbon formation. Catalytic performance was also evaluated by altering Pd and Zn composition of the Pd/ZnO/Al2O3 catalyst. Of the catalysts and conditions tested, selectivity toward liquid hydrocarbon was highest when using a 5% Pd metal loading and Pd/Zn molar ratio of 0.25 and mixed with HZMS-5, operating at 310oC and 300 psig, CO conversion was 43 % and selectivity (carbon weight basis) to hydrocarbons was 49 wt. %. Of the hydrocarbon fraction, 44wt. % was in the C5-C12 liquid product range and consisted primarily of aromatic

Enhanced aerobic biodegradation of some toxic hydrocarbon pollutants

International Nuclear Information System (INIS)

Elshahawy, M.R.M.

2007-01-01

samples were collected from the same location in Suez Gulf during the period from June, 2004 to April 2006 then microbiologically and chemically analyzed . the TPH levels ranged from 55 to 86 ppm and exceeded the known permissible limits referring to a settled situation of chronic hydrocarbon pollution in the studied area. on the other hand the biodegrading bacterial counts cfu clearly reflected the great adaptation of endogenous bacteria to use hydrocarbons as a sole source of carbon . the ratio of biodegrading bacteria to heterotrophic ones ranged between 26 and 50% over the period of collection. the biodegradation potentials of suez gulf consortia were studied at different concentrations of phenanthrene as a sole carbon source. it was found that the degradation kinetics of phenanthrene either due to biotic or abiotic factors is affected with the initial concentration of PAHs. twenty PAHs degraders were isolated from Suez Gulf consortia after different adaptation periods on phenanthrene.ten isolates were selected to be promising due to their ability to tolerate high base oil concentrations, grow at wide range of temperatures and their short incubation period on MSO. the biodegradation kinetics of 200 ppm phenanthrene by the selected isolates was monitored by HPLC

Gamma-radiation induced polymerization of methyl methacrylate in aliphatic hydrocarbons: kinetics and evidence for incorporation of hydrocarbon in the polymer chain

International Nuclear Information System (INIS)

Mohan, H.; Iyer, R.M.

1989-01-01

On γ-radiolysis, the rate of polymerization of methyl methacrylate in hydrocarbon solvents is observed to decrease. It is explained by hydrocarbon entry into the polymer chains. The hydrocarbon entry into the polymer chains is observed to take place at later stages of polymerization and increases with hydrocarbon chain length. The extent of hydrocarbon entry into the polymer chains is estimated by NMR and GLC analysis. It is observed to be equal to ∼ 12% corresponding to ∼ 97 hexadecane molecules in each polymer chain. The IR, DSC, MW determination and radiation effects on the polymer showed evidences for hydrocarbon entry into the polymer. It is explained by chain transfer from the growing polymer radical to the hydrocarbon molecules. The chain transfer constant is determined to be equal to 1 x 10 -2 . (author)

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2005-07-01

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

Evaluation of the Removal of Hydrocarbons from Soil Media Using Persulfate Oxidation in the Presence of Mineral Siderite

Directory of Open Access Journals (Sweden)

Farzad Mohammadi

2016-09-01

Full Text Available Introduction and purpose: Soil contamination by petroleum is mostly resulted from oil exploration, refining processes, leaking of oil products from storage tanks, leaking from pipelines due to pipe friction and decay, refinery wastewater discharge and agricultural irrigation with such materials. Sodium persulfate (Na2S2O8, which is a chemical oxidant, could be activated in the presence of ferrous (Fe2+ and, leading to the treatment of a wide range of soil contaminants. Therefore, this study aimed to evaluate the removal of hydrocarbons from soil media using persulfate oxidation in the presence of mineral siderite. Methods: Initially, oil-contaminated soil was prepared in the form of two separate samples, including silt-clay and sandy-loam soils, which were orderly spiked with 5000 mg fuel oil per kilogram of dry soil. Following that, the effects of various factors, such as different concentrations of persulfate (100-500 mmol/L and siderite (0.1-0.5 g/L, pH (3-9 and temperature (20-60◦C and the removal of petroleum hydrocarbon were assessed.Results: In this study, the optimum condition for degeneration of total petroleum hydrocarbon in silt-clay soils was reported, as follows: temperature: 60◦C, pH: 3, and persulfate/siderite molar ratio of 400 mmol/L to 4.0 g/L. Meanwhile, the optimum condition for the removal of hydrocarbon from sandy-loam soils was pH: 3, temperature: 60◦C and persulfate/siderite molar ratio of 300 mmol/L to 3.0 g/L.Conclusion: According to the results of this study, the optimal amount of persulfate and siderite could be used to remove hydrocarbons from contaminated soils.

Russia and China hydrocarbon relations. A building block toward international hydrocarbon regulation?

International Nuclear Information System (INIS)

Locatelli, Catherine; Abbas, Mehdi; Rossiaud, Sylvain

2015-12-01

This article is a first step of a research agenda on international hydrocarbon regulations. With regards to both: i) the new wealth and power equilibrium in the international political economy and ii) the new political economy of carbon that is emerging from The Paris agreement on Climate changes, this research agenda aims at analysing the changing national structures of governance and the ways these changes lead to international, bilateral, pluri-lateral or multilateral hydrocarbon regulation

PROPERTIES OF POLYCYCLIC AROMATIC HYDROCARBONS IN THE NORTHWEST PHOTON DOMINATED REGION OF NGC 7023. III. QUANTIFYING THE TRADITIONAL PROXY FOR PAH CHARGE AND ASSESSING ITS ROLE

Energy Technology Data Exchange (ETDEWEB)

Boersma, C.; Bregman, J.; Allamandola, L. J., E-mail: Christiaan.Boersma@nasa.gov [NASA Ames Research Center, MS 245-6, Moffett Field, CA 94035-0001 (United States)

2015-06-10

Polycyclic aromatic hydrocarbon (PAH) emission in the Spitzer/IRS spectral map of the northwest photon dominated region (PDR) in NGC 7023 is analyzed. Here, results from fitting the 5.2–14.5 μm spectrum at each pixel using exclusively PAH spectra from the NASA Ames PAH IR Spectroscopic Database (www.astrochem.org/pahdb/) and observed PAH band strength ratios, determined after isolating the PAH bands, are combined. This enables the first quantitative and spectrally consistent calibration of PAH charge proxies. Calibration is straightforward because the 6.2/11.2 μm PAH band strength ratio varies linearly with the ionized fraction (PAH ionization parameter) as determined from the intrinsic properties of the individual PAHs comprising the database. This, in turn, can be related to the local radiation field, electron density, and temperature. From these relations diagnostic templates are developed to deduce the PAH ionization fraction and astronomical environment in other objects. The commonly used 7.7/11.2 μm PAH band strength ratio fails as a charge proxy over a significant fraction of the nebula. The 11.2/12.7 μm PAH band strength ratio, commonly used as a PAH erosion indicator, is revealed to be a better tracer for PAH charge across NGC 7023. Attempting to calibrate the 12.7/11.2 μm PAH band strength ratio against the PAH hydrogen adjacency ratio (duo+trio)/solo is, unexpectedly, anti-correlated. This work both validates and extends the results from Paper I and Paper II.

Allocation of multiple, widely spread oil spills associated with one polluter : GC-MS fingerprinting and diagnostic ratios of spilled oil and oiled seabirds

International Nuclear Information System (INIS)

Hansen, A.B.; Avnskjold, J.

2005-01-01

In January 2005, a Cypriot cargo ship leaked about 5 tons of heavy fuel bunker oil in Kerteminde Bay in the Great Belt, Denmark. The ship was stopped to inspect and collect oil samples from its 2 damaged tanks for forensic oil spill identification by gas chromatography and mass spectrometry. Two weeks following the accident, a series of waterborne and stranded oil spills showed up in the Great Belt area, north and south of the vessel's route. Thousands of oiled seabirds on small islands and coastlines were affected. The Danish Coast Guard suspected that the vessel might be responsible for the observed spills. More than 50 oil samples were collected and sent for forensic analysis at the National Environmental Research Institute. Both waterborne and stranded spill samples showed an almost perfect match of diagnostic ratios and chromatograph with the potential responsible party (PRP) bunker. The spill samples therefore matched the reference oil and were allocated to the spill associated with the Cypriot cargo ship. One sample deviated significantly from the other samples and was not allocated to the ship's accidental spill. Oil samples collected from oiled seabirds showed larger variations between diagnostic ratios and the reference bunker oils. The variations can be attributed to weathering and biodegradation, but also to contamination by non-petrogenic material. It was concluded that the oiled seabirds represented non-match samples that cannot be allocated to the oil spill associated with the Cypriot cargo ship. 14 refs., 3 tabs., 4 figs

27 CFR 21.125 - Rubber hydrocarbon solvent.

Science.gov (United States)

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Rubber hydrocarbon solvent. 21.125 Section 21.125 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU....125 Rubber hydrocarbon solvent. (a) Rubber hydrocarbon solvent is a petroleum derivative. (b...

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)

Diagnostic Accuracy of Preoperative Neutrophil-to-Lymphocyte and Platelet-to-Lymphocyte Ratios in Detecting Occult Papillary Thyroid Microcarcinomas in Benign Multinodular Goitres

Directory of Open Access Journals (Sweden)

Dimitrios K. Manatakis

2018-01-01

Full Text Available Objective. To investigate the diagnostic accuracy of neutrophil-to-lymphocyte (NLR and platelet-to-lymphocyte (PLR ratios in detecting occult papillary thyroid microcarcinomas in benign, multinodular goitres. Methods. 397 total thyroidectomy patients were identified from the institutional thyroid surgery database between 2007 and 2016 (94 males, 303 females, mean age 53 ± 14.5 years. NLR and PLR were calculated as the absolute neutrophil and absolute platelet counts divided by the absolute lymphocyte count, respectively, based on the preoperative complete blood cell count. Results. NLR was significantly higher in carcinomas and microcarcinomas compared to benign pathology (p=0.026, whereas a direct association could not be established for PLR. Both NLR and PLR scored low in all parameters of diagnostic accuracy, with overall accuracy ranging between 45 and 50%. Conclusions. As surrogate indices of the systemic inflammatory response, NLR and PLR are inexpensive and universally available from routine blood tests. Although we found higher NLR values in cases of malignancy, NLR and PLR cannot effectively predict the presence of occult papillary microcarcinomas in otherwise benign, multinodular goitres.

A method for removing sulfur bearing compounds from paraffinous hydrocarbons or a directly distilled benzine fraction

Energy Technology Data Exchange (ETDEWEB)

Konyukhova, T.P.; Bolotskaya, I.A.; Mikhaylova, L.A.; Sadykov, A.N.; Shitovkin, N.T.; Vlasov, V.V.

1983-01-01

In the known method for removing sulfurorganic compounds from paraffinous hydrocarbons or a directly distilled gasoline fraction through their adsorption using natural zeolite, in order to increase the degree of purification, clinoptilolite (Kp), which contains SiO2 and A12O3 in a molar ratio of 10.6 to 16.7 is used as the natural zeolite. The purification of the paraffinous hydrocarbons through clinoptilolite adsorption as compared with mordenite adsorption makes it possible to increase the degree of their purification of ethylmercaptane and dimethylsulfide. The effectiveness of clinoptilolite is also confirmed in removing mercaptanes and sulfides from directly distilled gasoline fractions.

Molecular Diagnostics of Fusion and Laboratory Plasmas

Science.gov (United States)

Fantz, U.

2005-05-01

The presence of molecules in the cold scrape-off layer of fusion experiments and industrial plasmas requires an understanding of the molecular dynamics in these low temperature plasmas. Suitable diagnostic methods can provide an insight in molecular processes in the plasma volume as well as for plasma surface interactions. A very simple but powerful technique is the molecular emission spectroscopy. Spectra are obtained easily, whereas interpretation might be very complex and relies on the availability of atomic and molecular data. Examples are given for hydrogen plasmas and plasmas with hydrocarbons which both are of importance in industrial applications as well as in fusion experiments.

Molecular Diagnostics of Fusion and Laboratory Plasmas

International Nuclear Information System (INIS)

Fantz, U.

2005-01-01

The presence of molecules in the cold scrape-off layer of fusion experiments and industrial plasmas requires an understanding of the molecular dynamics in these low temperature plasmas. Suitable diagnostic methods can provide an insight in molecular processes in the plasma volume as well as for plasma surface interactions. A very simple but powerful technique is the molecular emission spectroscopy. Spectra are obtained easily, whereas interpretation might be very complex and relies on the availability of atomic and molecular data. Examples are given for hydrogen plasmas and plasmas with hydrocarbons which both are of importance in industrial applications as well as in fusion experiments

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.

Hydrocarbon-degrading bacteria isolation and surfactant influence ...

African Journals Online (AJOL)

Hydrocarbons are substantially insoluble in water, often remaining partitioned in the non-aqueous phase liquid (NAPL). However, there had been little or no attempts to advance the bioavailability of hydrocarbons through the use of surfactants. This study was conducted based on the need to isolate hydrocarbon degrading ...

Sensitivity ranking for freshwater invertebrates towards hydrocarbon contaminants.

Science.gov (United States)

Gerner, Nadine V; Cailleaud, Kevin; Bassères, Anne; Liess, Matthias; Beketov, Mikhail A

2017-11-01

Hydrocarbons have an utmost economical importance but may also cause substantial ecological impacts due to accidents or inadequate transportation and use. Currently, freshwater biomonitoring methods lack an indicator that can unequivocally reflect the impacts caused by hydrocarbons while being independent from effects of other stressors. The aim of the present study was to develop a sensitivity ranking for freshwater invertebrates towards hydrocarbon contaminants, which can be used in hydrocarbon-specific bioindicators. We employed the Relative Sensitivity method and developed the sensitivity ranking S hydrocarbons based on literature ecotoxicological data supplemented with rapid and mesocosm test results. A first validation of the sensitivity ranking based on an earlier field study has been conducted and revealed the S hydrocarbons ranking to be promising for application in sensitivity based indicators. Thus, the first results indicate that the ranking can serve as the core component of future hydrocarbon-specific and sensitivity trait based bioindicators.

Diagnostic Role of Neutrophil-Lymphocyte Ratio in Oral Cavity ...

African Journals Online (AJOL)

2018-02-07

Feb 7, 2018 ... operating characteristics curve analysis suggested cutoff value of ... helpful in identifying the oral cavity lesions at high risk for harboring malignancy. ... After taking approval from local ethics committee, ... used for comparison of gender distributions. ... difference in M/F ratio revealed between groups (P =.

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...

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)

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)

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.

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.

Spatial Distribution of Polycyclic Aromatic Hydrocarbon (PAH) Concentrations in Soils from Bursa, Turkey.

Science.gov (United States)

Karaca, Gizem

2016-02-01

The objectives of this study were to identify regional variations in soil polycyclic aromatic hydrocarbon (PAH) contamination in Bursa, Turkey, and to determine the distributions and sources of various PAH species and their possible sources. Surface soil samples were collected from 20 different locations. The PAH concentrations in soil samples were analyzed using gas chromatography-mass spectrometry (GC-MS). The total PAH concentrations (∑12 PAH) varied spatially between 8 and 4970 ng/g dry matter (DM). The highest concentrations were measured in soils taken from traffic+barbecue+ residential areas (4970 ng/g DM) and areas with cement (4382 ng/g DM) and iron-steel (4000 ng/g DM) factories. In addition, the amounts of ∑7 carcinogenic PAH ranged from 1 to 3684 ng/g DM, and between 5 and 74 % of the total PAHs consisted of such compounds. Overall, 4-ring PAH compounds (Fl, Pyr, BaA and Chr) were dominant in the soil samples, with 29-82 % of the ∑12 PAH consisting of 4-ring PAH compounds. The ∑12 BaPeq values ranged from 0.1 to 381.8 ng/g DM. Following an evaluation of the molecular diagnostic ratios, it was concluded that the PAH pollution in Bursa soil was related to pyrolytic sources; however, the impact of petrogenic sources should not be ignored.

Polycyclic Aromatic Hydrocarbons in the Dagang Oilfield (China: Distribution, Sources, and Risk Assessment

Directory of Open Access Journals (Sweden)

Haihua Jiao

2015-05-01

Full Text Available The levels of 16 polycyclic aromatic hydrocarbons (PAHs were investigated in 27 upper layer (0–25 cm soil samples collected from the Dagang Oilfield (China in April 2013 to estimate their distribution, possible sources, and potential risks posed. The total concentrations of PAHs (∑PAHs varied between 103.6 µg·kg−1 and 5872 µg·kg−1, with a mean concentration of 919.8 µg·kg−1; increased concentrations were noted along a gradient from arable desert soil (mean 343.5 µg·kg−1, to oil well areas (mean of 627.3 µg·kg−1, to urban and residential zones (mean of 1856 µg·kg−1. Diagnostic ratios showed diverse source of PAHs, including petroleum, liquid fossil fuels, and biomass combustion sources. Combustion sources were most significant for PAHs in arable desert soils and residential zones, while petroleum sources were a significant source of PAHs in oilfield areas. Based ontheir carcinogenity, PAHs were classified as carcinogenic (B or not classified/non-carcinogenic (NB. The total concentrations of carcinogenic PAHs (∑BPAHs varied from 13.3 µg·kg−1 to 4397 µg·kg−1 across all samples, with a mean concentration of 594.4 µg·kg−1. The results suggest that oilfield soil is subject to a certain level of ecological environment risk.

Using Lead Concentrations and Stable Lead Isotope Ratios to Identify Contamination Events in Alluvial Soils

International Nuclear Information System (INIS)

Saint-Laurent, D.; St-Laurent, J.; Hahni, M.; Chapados, C.; Ghaleb, B.

2010-01-01

Soils contaminated with hydrocarbons (C10,C50), polycyclic aromatic hydrocarbons (PAHs), and other contaminants (e.g., As, Cd, Cu, Pb) were recently discovered on the banks of the Saint-Francois and Massawippi rivers. Alluvial soils are contaminated over a distance of 100 kilometers, and the level of the contaminated-hydrocarbon layer in the soil profiles is among the highest at the Windsor and Richmond sites. Concentrations of lead and stable lead isotope ratios ( 204 Pb/ 206 Pb, 206 Pb/ 207 Pb, 208 Pb/ 20 '6Pb) are also used to identify contamination events. The maximum and minimum values detected in soil profiles for arsenic, cadmium, and lead vary from 3.01 to 37.88?mg kg -1 (As), 0.11 to 0.81?mg kg-1 (Cd) 12.32 to 149.13?mg kg -1 (Pb), respectively, while the 207 Pb/ 206 Pb isotopic ratio values are between 0.8545 and 0.8724 for all the profiles. The highest values of trace elements (As, Pb and Zn) were detected in the hydrocarbon layer (C10,C50), most often located at the bottom of the profiles (160, 200, and 220 cm in depth). The various peaks recorded in the soils and the position of the profiles suggest that various contaminants were transported by the river on several occasions and infiltrated the soil matrix or deposited on flood plains during successive floods. Atmospheric particles which entered the river or deposited on riverbanks must also be considered as another source of pollution recorded in soils

Using Lead Concentrations and Stable Lead Isotope Ratios to Identify Contamination Events in Alluvial Soils

Directory of Open Access Journals (Sweden)

Diane Saint-Laurent

2010-01-01

Full Text Available Soils contaminated with hydrocarbons (C10–C50, polycyclic aromatic hydrocarbons (PAHs, and other contaminants (e.g., As, Cd, Cu, Pb were recently discovered on the banks of the Saint-François and Massawippi rivers. Alluvial soils are contaminated over a distance of 100 kilometers, and the level of the contaminated-hydrocarbon layer in the soil profiles is among the highest at the Windsor and Richmond sites. Concentrations of lead and stable lead isotope ratios (204Pb/206Pb, 207Pb/206Pb, 208Pb/206Pb are also used to identify contamination events. The maximum and minimum values detected in soil profiles for arsenic, cadmium, and lead vary from 3.01 to 37.88 mg kg-1 (As, 0.11 to 0.81 mg kg-1 (Cd 12.32 to 149.13 mg kg-1 (Pb, respectively, while the 207Pb/206Pb isotopic ratio values are between 0.8545 and 0.8724 for all the profiles. The highest values of trace elements (As, Pb and Zn were detected in the hydrocarbon layer (C10–C50, most often located at the bottom of the profiles (160, 200, and 220 cm in depth. The various peaks recorded in the soils and the position of the profiles suggest that various contaminants were transported by the river on several occasions and infiltrated the soil matrix or deposited on floodplains during successive floods. Atmospheric particles which entered the river or deposited on riverbanks must also be considered as another source of pollution recorded in soils.

Rate constants for the reaction of CF3O radicals with hydrocarbons at 298 K

DEFF Research Database (Denmark)

Kelly, C.; Treacy, J.; Sidebottom, H.W.

1993-01-01

Rate constant ratios of the reactions of CF3O radicals with a number of hydrocarbons have been determined at 298 +/- 2 K and atmospheric pressure using a relative rate method. Using a previously determined value k(CF30 + C2H6) = 1.2 x 10(-12) cm3 molecule-1 s-1 these rate constant ratios provide...... estimates of the rate constants: k(CF3O + CH4) = (1.2 +/- 0.1) x 10(-14), k(CF3O + c-C3H6) = (3.6 +/- 0.2) x 10(-13), k(CF3O + C3H8) = (4.7 +/- 0.7) x 10(-12), k(CF3O + (CH3)3CH) = (7.2 +/- 0.5) x 10(-12), k(CF3O + C2H4) = (3.0 +/- 0.1) x 10(-11) and k(CF3O + C6H6) = (3.6 +/- 0.1) x 10(-11) cm3 molecule-1 s......-1. The importance of the reactions of CF3O radicals with hydrocarbons under atmospheric conditions is discussed....

Air-dust-borne associations of phototrophic and hydrocarbon-utilizing microorganisms: promising consortia in volatile hydrocarbon bioremediation.

Science.gov (United States)

Al-Bader, Dhia; Eliyas, Mohamed; Rayan, Rihab; Radwan, Samir

2012-11-01

Aquatic and terrestrial associations of phototrophic and heterotrophic microorganisms active in hydrocarbon bioremediation have been described earlier. The question arises: do similar consortia also occur in the atmosphere? Dust samples at the height of 15 m were collected from Kuwait City air, and analyzed microbiologically for phototrophic and heterotrophic hydrocarbon-utilizing microorganisms, which were subsequently characterized according to their 16S rRNA gene sequences. The hydrocarbon utilization potential of the heterotrophs alone, and in association with the phototrophic partners, was measured quantitatively. The chlorophyte Gloeotila sp. and the two cyanobacteria Nostoc commune and Leptolyngbya thermalis were found associated with dust, and (for comparison) the cynobacteria Leptolyngbya sp. and Acaryochloris sp. were isolated from coastal water. All phototrophic cultures harbored oil vapor-utilizing bacteria in the magnitude of 10(5) g(-1). Each phototrophic culture had its unique oil-utilizing bacteria; however, the bacterial composition in Leptolyngbya cultures from air and water was similar. The hydrocarbon-utilizing bacteria were affiliated with Acinetobacter sp., Aeromonas caviae, Alcanivorax jadensis, Bacillus asahii, Bacillus pumilus, Marinobacter aquaeolei, Paenibacillus sp., and Stenotrophomonas maltophilia. The nonaxenic cultures, when used as inocula in batch cultures, attenuated crude oil in light and dark, and in the presence of antibiotics and absence of nitrogenous compounds. Aqueous and diethyl ether extracts from the phototrophic cultures enhanced the growth of the pertinent oil-utilizing bacteria in batch cultures, with oil vapor as a sole carbon source. It was concluded that the airborne microbial associations may be effective in bioremediating atmospheric hydrocarbon pollutants in situ. Like the aquatic and terrestrial habitats, the atmosphere contains dust-borne associations of phototrophic and heterotrophic hydrocarbon

The distribution and sources of polycyclic aromatic hydrocarbons in shallow groundwater from an alluvial-diluvial fan of the Hutuo River in North China

Science.gov (United States)

Wang, Jincui; Zhao, Yongsheng; Sun, Jichao; Zhang, Ying; Liu, Chunyan

2018-06-01

This paper has investigated the concentration and distribution of polycyclic aromatic hydrocarbons in shallow groundwater from an alluvial-diluvial fan of the Hutuo River in North China. Results show that the concentration levels of 16 priority polycyclic aromatic hydrocarbons range from 0 to 92.06 ng/L, do not conform to drinking water quality standards in China (GB 5749- 2006). However, the concentration figures of priority polycyclic aromatic hydrocarbons are much lower than that of other studies conducted elsewhere in China. In addition, highly-concentrated polycyclic aromatic hydrocarbons (50-92 ng/L) are fragmentarily distributed. The composition of polycyclic aromatic hydrocarbons from this study indicates that low molecular polycyclic aromatic hydrocarbons are predominant in groundwater samples, medium molecular compounds occur at low concentrations, and high molecular hydrocarbons are not detected. The polycyclic aromatic hydrocarbon composition in groundwater samples is basically the same as that of gaseous samples in the atmosphere in this study. Therefore, the atmospheric input is assumed to be an important source of polycyclic aromatic hydrocarbons, no less than wastewater discharge, adhesion on suspended solids, and surface water leakage. Ratios of specific polycyclic aromatic hydrocarbons demonstrate that they mainly originate from wood or coal combustion as well as natural gas and partially from petroleum according to the result of principal component analysis. On the whole, conclusions are drawn that the contamination sources of these polycyclic aromatic hydrocarbons are likely petrogenic and pyrolytic inputs. Future investigations by sampling topsoil, vadose soil, and the atmosphere can further verify aforementioned conclusions.

Bioremediation: Technology for treating hydrocarbon-contaminated wastewater

Energy Technology Data Exchange (ETDEWEB)

Towprayoon, S.; Kuntrangwattana, S. [King Mongkut`s Institute of Technology, Bangkok (Thailand)

1996-12-31

Cutting oil wastewater from an iron and steel factory was applied to the soil windrow. Self-remediation was then compared with remediation with acclimatized indigenous microbes. The incremental reduction rate of the microorganisms and hydrocarbon-degradable microbes was slower in self-remediation than in the latter treatment. Within 30 days, when the acclimatized indigenous microbes were used, there was a significant reduction of the contaminated hydrocarbons, while self-remediation took longer to reduce to the same concentration. Various nitrogen sources were applied to the soil pile, namely, organic compost, chemical fertilizer, ammonium sulfate, and urea. The organic compost induced a high yield of hydrocarbon-degradable microorganisms, but the rate at which the cutting oil in the soil decreased was slower than when other nitrogen sources were used. The results of cutting oil degradation studied by gas chromatography showed the absence of some important hydrocarbons. The increment of the hydrocarbon-degradable microbes in the land treatment ecosystem does not necessarily correspond to the hydrocarbon reduction efficiency. 3 refs., 3 figs.

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

Influence of fuel type, dilution and equivalence ratio on the emission reduction from the auto-ignition in an Homogeneous Charge Compression Ignition engine

Energy Technology Data Exchange (ETDEWEB)

Machrafi, Hatim [UPMC Universite Paris 06, ENSCP, 11 rue de Pierre et Marie Curie, 75005 Paris (France); UPMC Universite Paris 06, Institut Jean Le Rond D' Alembert, 4 place Jussieu, 75252 Paris cedex 05 (France); Universite Libre de Bruxelles, TIPs - Fluid Physics, CP165/67, 50 Avenue F.D. Roosevelt, 1050 Brussels (Belgium); Cavadias, Simeon [UPMC Universite Paris 06, ENSCP, 11 rue de Pierre et Marie Curie, 75005 Paris (France); UPMC Universite Paris 06, Institut Jean Le Rond D' Alembert, 4 place Jussieu, 75252 Paris cedex 05 (France); Amouroux, Jacques [UPMC Universite Paris 06, ENSCP, 11 rue de Pierre et Marie Curie, 75005 Paris (France)

2010-04-15

One technology that seems to be promising for automobile pollution reduction is the Homogeneous Charge Compression Ignition (HCCI). This technology still faces auto-ignition and emission-control problems. This paper focuses on the emission problem, since it is incumbent to realize engines that pollute less. For this purpose, this paper presents results concerning the measurement of the emissions of CO, NO{sub x}, CO{sub 2}, O{sub 2} and hydrocarbons. HCCI conditions are used, with equivalence ratios between 0.26 and 0.54, inlet temperatures of 70 C and 120 C and compression ratios of 10.2 and 13.5, with different fuel types: gasoline, gasoline surrogate, diesel, diesel surrogate and mixtures of n-heptane/toluene. The effect of dilution is considered for gasoline, while the effect of the equivalence ratio is considered for all the fuels. No significant amount of NO{sub x} has been measured. It appeared that the CO, O{sub 2} and hydrocarbon emissions were reduced by decreasing the toluene content of the fuel and by decreasing the dilution. The opposite holds for CO{sub 2}. The reduction of the hydrocarbon emission appears to compete with the reduction of the CO{sub 2} emission. Diesel seemed to produce less CO and hydrocarbons than gasoline when auto-ignited. An example of emission reduction control is presented in this paper. (author)

Preliminary Geospatial Analysis of Arctic Ocean Hydrocarbon Resources

Energy Technology Data Exchange (ETDEWEB)

Long, Philip E.; Wurstner, Signe K.; Sullivan, E. C.; Schaef, Herbert T.; Bradley, Donald J.

2008-10-01

Ice coverage of the Arctic Ocean is predicted to become thinner and to cover less area with time. The combination of more ice-free waters for exploration and navigation, along with increasing demand for hydrocarbons and improvements in technologies for the discovery and exploitation of new hydrocarbon resources have focused attention on the hydrocarbon potential of the Arctic Basin and its margins. The purpose of this document is to 1) summarize results of a review of published hydrocarbon resources in the Arctic, including both conventional oil and gas and methane hydrates and 2) develop a set of digital maps of the hydrocarbon potential of the Arctic Ocean. These maps can be combined with predictions of ice-free areas to enable estimates of the likely regions and sequence of hydrocarbon production development in the Arctic. In this report, conventional oil and gas resources are explicitly linked with potential gas hydrate resources. This has not been attempted previously and is particularly powerful as the likelihood of gas production from marine gas hydrates increases. Available or planned infrastructure, such as pipelines, combined with the geospatial distribution of hydrocarbons is a very strong determinant of the temporal-spatial development of Arctic hydrocarbon resources. Significant unknowns decrease the certainty of predictions for development of hydrocarbon resources. These include: 1) Areas in the Russian Arctic that are poorly mapped, 2) Disputed ownership: primarily the Lomonosov Ridge, 3) Lack of detailed information on gas hydrate distribution, and 4) Technical risk associated with the ability to extract methane gas from gas hydrates. Logistics may control areas of exploration more than hydrocarbon potential. Accessibility, established ownership, and leasing of exploration blocks may trump quality of source rock, reservoir, and size of target. With this in mind, the main areas that are likely to be explored first are the Bering Strait and Chukchi

Process for in-situ biodegradation of hydrocarbon contaminated soil

International Nuclear Information System (INIS)

Ely, D.L.; Heffner, D.A.

1991-01-01

This patent describes an in situ process for biodegrading hydrocarbons by drawing oxygen into an undisturbed hydrocarbon contaminated zone in a fluid permeable soil. It comprises: establishing a borehole extending from the earth's surface through a hydrocarbon contaminated zone having hydrocarbon degrading microbes therein; lining the borehole with a fluid impermeable liner coaxially spaced and sealingly connected to the inside surface of the borehole and extending from the earth's surface to the hydrocarbon-contaminated zone; the liner including a fluid permeable portion extending from the lower end thereof and through at least a portion of the hydrocarbon contaminated zone, fluidly connecting a source of negative pressure to the fluid impermeable line; evacuating gas from the borehole through the fluid permeable portion of the liner at a rate sufficient to draw air from the earth's surface into the hydrocarbon containing zone; and adjusting the flow rate of the evacuated gas so that the amount of hydrocarbon biodegradation therein is within 50% of the maximum hydrocarbon biodegradation rate as detected by the volume of carbon dioxide in the evacuated gas

Changes in Atmospheric Butanes and Pentanes and Their Isomeric Ratios in the Continental United States

Science.gov (United States)

Rossabi, Sam; Helmig, Detlev

2018-04-01

Nonmethane hydrocarbons have been used as tracers in research on emissions and atmospheric oxidation chemistry. This research investigates source region mixing ratio trends of the nonmethane hydrocarbons i-butane, n-butane, i-pentane, and n-pentane, and the (i/n) isomeric ratios of these compounds between 2001 and 2015. Data collected at Photochemical Assessment Monitoring Stations, mandated by the U.S. Environmental Protection Agency in ozone nonattainment areas, and data collected at Global Greenhouse Gas Reference Network sites within the National Oceanic and Atmospheric Administration network, and analyzed at the Institute of Arctic and Alpine Research at the University of Colorado-Boulder, were examined. Among all considered species, linear regression analyses on concentration time series had negative slopes at 81% of sites, indicating predominantly declining butane and pentane atmospheric concentrations. Mostly negative slopes (78% of sites) were found for the (i/n) butane and pentane isomeric ratios, including all six and seven statistically significant (i/n) butane and pentane trends, respectively. Over the 15 year investigation period and averaged over all sites, total relative changes were 30 and 45% for the (i/n) ratios of butanes and pentanes, respectively, with a relative increase in the prominence of the n-isomers. Most likely causes include changing isomeric ratios in gasoline sector emissions, and increasing influence of oil and natural gas industry emissions. Changes in concentrations and isomeric ratios depend on proximity of contributing emission sources to measurement sites.

Measurement of the Water to Scintillator Charged-Current Cross-Section Ratio for Muon Neutrinos at the T2K Near Detector

CERN Document Server

AUTHOR|(CDS)2083872

2017-10-02

The T2K experiment is a 295-km long-baseline neutrino experiment which aims at the measurement of neutrino oscillation parameters. Precise measurements of these parameters require accurate extrapolation of interaction rates from the near detector, ND280, mainly made of scintillator (hydrocarbon), to Super-Kamiokande, the water Cherenkov far detector. Measurements on water and of the water to hydrocarbon ratio, contribute to eliminate the uncertainties arising from carbon/oxygen differences. The cross section on water is obtained by subtraction of event distributions in two almost identical sub-detectors, one of which is equipped with water-filled modules. The measurement is performed by selecting a muon neutrino charged-current sample, in an exposure of 5.80 × 10^(20) protons on target. The water to hydrocarbon cross-section ratio is extracted for good acceptance kinematic regions (only forward muons with momentum higher than 100 MeV), in bins of reconstructed energy, the very quantity used in T2K oscillatio...

Characteristics of atmospheric non-methane hydrocarbons during haze episode in Beijing, China.

Science.gov (United States)

Guo, Songjun; Tan, Jihua; Duan, Jingchun; Ma, Yongliang; Yang, Fumo; He, Kebin; Hao, Jimin

2012-12-01

This study firstly focused on non-methane hydrocarbons (NMHCs) during three successive days with haze episode (16-18 August 2006) in Beijing. Concentrations of alkanes, alkenes, aromatic hydrocarbons, and ethyne all peaked at traffic rush hour, implying vehicular emission; and alkanes also peaked at non-traffic rush hour in the daytime, implying additional source. Especially, alkanes and aromatics clearly showed higher levels in the nighttime than that in the daytime, implying their active photochemical reactions in the daytime. Correlation coefficients (R (2)) showed that propane, n-butane, i-butane, ethene, propene, and benzene correlated with ethyne (R (2) = 0.61-0.66), suggesting that their main source is vehicular emission; 2-methylpentane and n-hexane correlated with i-pentane (R (2) = 0.61-0.64), suggesting that gasoline evaporation is their main source; and ethylbezene, m-/p-xylene, and o-xylene correlated with toluene (R (2) = 0.60-0.79), suggesting that their main source is similar to that of toluene (e.g., solvent usage). The R (2) of ethyne, i-pentane, and toluene with total NMHCs were 0.58, 0.76, and 0.60, respectively, indicating that ambient hydrocarbons are associated with vehicular emission, gasoline evaporation, and solvent usage. The sources of other hydrocarbons (e.g., ethane) might be natural gas leakage, biogenic emission, or long-range transport of air pollutants. Measured higher mean B/T ratio (0.78 ± 0.27) was caused by the more intensive photochemical activity of toluene than benzene, still indicating the dominant emission from vehicles.

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.

Hydrocarbon contamination of coastal sediments from the Sfax area (Tunisia), Mediterranean Sea.

Science.gov (United States)

Louati, A; Elleuch, B; Kallel, M; Saliot, A; Dagaut, J; Oudot, J

2001-06-01

The coastal area off the city of Sfax (730,000 inhabitants), well-known for fisheries and industrial activities, receives high inputs of organic matter mostly anthropogenic. Eighteen stations were selected in the vicinity of the direct discharge of industrial sewage effluents in the sea in order to study the spatial distribution of the organic contamination. Surface sediments sampled in the shallow shelf were analysed for hydrocarbons by Fourier transform infrared spectroscopy, gas chromatography and gas chromatography/mass spectrometry. Total hydrocarbon distributions revealed high contamination as compared to other coastal Mediterranean sites, with an average concentration of 1865 ppm/dry weight sediment. Gas chromatographic distribution patterns, values of unresolved mixture/n-alkane ratio and distributions of steranes and hopanes confirmed a petroleum contamination of the Arabian light crude oil type. Biogenic compounds were also identified with a series of short-chain carbon-numbered n-alkenes in the carbon range 16-24.

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

Science.gov (United States)

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

2013-02-01

Light hydrocarbons in soil have been used as direct indicators in geochemical hydrocarbon exploration, which remains an unconventional path in the petroleum industry. The occurrence of adsorbed soil gases, methane and heavier homologues were recorded in the near-surface soil samples collected from Kutch-Saurashtra, India. Soil gas alkanes were interpreted to be derived from deep-seated hydrocarbon sources and have migrated to the surface through structural discontinuities. The source of hydrocarbons is assessed to be thermogenic and could have been primarily derived from humic organic matter with partial contribution from sapropelic matter. Gas chromatographic analyses of hydrocarbons desorbed from soil samples through acid extraction technique showed the presence of methane through n-butane and the observed concentrations (in ppb) vary from: methane (C1) from 4-291, ethane (C2) from 0-84, propane (C3) from 0-37, i-butane (iC4) from 0-5 and n-butane (nC4) from 0-4. Carbon isotopes measured for methane and ethane by GC-C-IRMS, range between -42.9‰ to -13.3‰ (Pee Dee Belemnite - PDB) and -21.2‰ to -12.4‰ (PDB), respectively. The increased occurrence of hydrocarbons in the areas near Anjar of Kutch and the area south to Rajkot of Saurashtra signifies the area potential for oil and gas.

In-situ hydrocarbon delineation using laser-induced fluorescence

International Nuclear Information System (INIS)

Taer, A.D.; Hastings, R.W.; Brown, A.Y.; Frend, R.

1996-01-01

An investigation of hydrocarbons in soils was conducted at an active Shell Oil Company petroleum products terminal, located in Carson, California. An investigation approach involving Laser-Induced Fluorescence (LIF) and Cone Penetrometer Testing (CPT) technologies was implemented to provide real-time, in-situ characterization of site stratigraphy, hydrocarbon distribution and importantly, hydrocarbon product differentiation. The area of investigation is located along a property boundary, where a plume of separate phase hydrocarbons has been actively recovered for several years. CPT/LIF technology was selected for the investigation since previous delineation efforts using hydrocarbon fingerprinting methods proved inconclusive. Additionally, the CPT/LIF technology had the potential to provide a cost effective solution to accomplish project objectives. Based on the information obtained during this investigation, it was determined that the plume of separate phase hydrocarbons along the northern property boundary is from a source distinctly different than any identified hydrocarbons known to be from on-site sources. In addition, the plume was determined to not be connected with any other known on-site hydrocarbon plumes. The results of this CPT/LIF investigation were consistent with the known hydrogeologic conditions. This evaluation determined that CPT/LIF technology was very effective in addressing project objectives and resulted in a significant cost savings

Constructed wetlands for treatment of dissolved phase hydrocarbons

Energy Technology Data Exchange (ETDEWEB)

Moore, B J; Ross, S D [Komex International, Calgary, AB (Canada); Gibson, D [Calgary Univ., AB (Canada); Hardisty, P E [Komex Clarke Bond, Bristol (United Kingdom)

1999-01-01

The use of constructed wetlands as an alternative to conventional treatment of condensate-contaminated groundwater was studied. In 1997 a pilot scale wetland was constructed and implemented at the Gulf Strachan Gas Processing Plant to determine its ability in treating extracted groundwater contaminated with natural gas condensates. This paper presented the results of hydrocarbon removal efficiency, hydrocarbon removal mechanisms, winter operation, and the effect of hydrocarbons on vegetation health. The inflow water to the wetland contains 15 to 20 mg/L of C[sub 5]-C[sub 10] hydrocarbons, including 50 per cent BTEX compounds. During the summer months, hydrocarbon removal efficiency was 100 per cent, but decreased to 60 and 30 per cent in the spring and late fall, respectively. The hydrocarbons not removed in the wetland were eventually removed along the outflow channel. Temperature was determined to be an important factor in the variable removal rates, particularly when there is no aeration. The main hydrocarbon removal mechanisms appear to be volatilization, biodegradation and dilution. At present, plant uptake is not a factor. 12 refs., 1 tab., 3 figs.

Constructed wetlands for treatment of dissolved phase hydrocarbons

International Nuclear Information System (INIS)

Moore, B.J.; Ross, S.D.; Gibson, D.; Hardisty, P.E.

1999-01-01

The use of constructed wetlands as an alternative to conventional treatment of condensate-contaminated groundwater was studied. In 1997 a pilot scale wetland was constructed and implemented at the Gulf Strachan Gas Processing Plant to determine its ability in treating extracted groundwater contaminated with natural gas condensates. This paper presented the results of hydrocarbon removal efficiency, hydrocarbon removal mechanisms, winter operation, and the effect of hydrocarbons on vegetation health. The inflow water to the wetland contains 15 to 20 mg/L of C 5 -C 10 hydrocarbons, including 50 per cent BTEX compounds. During the summer months, hydrocarbon removal efficiency was 100 per cent, but decreased to 60 and 30 per cent in the spring and late fall, respectively. The hydrocarbons not removed in the wetland were eventually removed along the outflow channel. Temperature was determined to be an important factor in the variable removal rates, particularly when there is no aeration. The main hydrocarbon removal mechanisms appear to be volatilization, biodegradation and dilution. At present, plant uptake is not a factor. 12 refs., 1 tab., 3 figs

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.

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

Development of in situ cleaning techniques for diagnostic mirrors in ITER

International Nuclear Information System (INIS)

Litnovsky, A.; Laengner, M.; Matveeva, M.; Schulz, Ch.; Marot, L.; Voitsenya, V.S.; Philipps, V.; Biel, W.; Samm, U.

2011-01-01

Mirrors will be used in all optical and laser-based diagnostic systems of ITER. In the severe environment, the optical characteristics of mirrors will be degraded, hampering the entire performance of the respective diagnostics. A minute impurity deposition of 20 nm of carbon on the mirror is sufficient to decrease the mirror reflectivity by tens of percent outlining the necessity of the mirror cleaning in ITER. The results of R and D on plasma cleaning of molybdenum diagnostic mirrors are reported. The mirrors contaminated with amorphous carbon films in the laboratory conditions and in the tokamaks were cleaned in steady-state hydrogenic plasmas. The maximum cleaning efficiency of 4.2 nm/min was reached for the laboratory and soft tokamak hydrocarbon films, whereas for the hard tokamak films the carbidization of mirrors drastically decreased the cleaning efficiency down to 0.016 nm/min. This implies the necessity of sputtering cleaning of contaminated mirrors as the only reliable tool to remove the deposits by plasma cleaning. An overview of R and D program on mirror cleaning is provided along with plans for further studies and the recommendations for ITER mirror-based diagnostics.

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.

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 ...

GC×GC measurements of C7-C11 aromatic and n-alkane hydrocarbons on Crete, in air from Eastern Europe during the MINOS campaign

Science.gov (United States)

Xu, X.; Williams, C.; Plass-Dülmer, H.; Berresheim, H.; Salisbury, G.; Lange, L.; Lelieveld, J.

2003-09-01

During the Mediterranean Intensive Oxidant Study (MINOS) campaign in August 2001 gas-phase organic compounds were measured using comprehensive two-dimensional gas chromatography (GCxGC) at the Finokalia ground station, Crete. In this paper, C7-C11 aromatic and n-alkane measurements are presented and interpreted. The mean mixing ratios of the hydrocarbons varied from 1±1 pptv (i-propylbenzene) to 43±36 pptv (toluene). The observed mixing ratios showed strong day-to-day variations and generally higher levels during the first half of the campaign. Mean diel profiles showed maxima at local midnight and late morning, and minima in the early morning and evening. Results from analysis using a simplified box model suggest that both the chemical sink (i.e. reaction with OH) and the variability of source strengths were the causes of the observed variations in hydrocarbon mixing ratios. The logarithms of hydrocarbon concentrations were negatively correlated with the OH concentrations integral over a day prior to the hydrocarbon measurements. Slopes of the regression lines derived from these correlations for different compounds are compared with literature rate constants for their reactions with OH. The slopes for most compounds agree reasonably well with the literature rate constants. A sequential reaction model has been applied to the interpretation of the relationship between ethylbenzene and two of its potential products, i.e. acetophenone and benzeneacetaldehyde. The model can explain the good correlation observed between [acetophenone]/[ethylbenzene] and [benzeneacetaldehyde]/[ethylbenzene]. The model results and field measurements suggest that the reactivity of benzeneacetaldehyde may lie between those of acetophenone and ethylbenzene and that the ratio between yields of acetophenone and benzeneacetaldehyde may be up to 28:1. Photochemical ages of trace gases sampled at Finokalia during the campaign are estimated using the sequential reaction model and related data

Separation of toluene from cyclic hydrocarbons using 1-butyl-3-methylimidazolium methylsulfate ionic liquid at T = 298.15 K and atmospheric pressure

International Nuclear Information System (INIS)

Dominguez, Irene; Calvar, Noelia; Gomez, Elena; Dominguez, Angeles

2011-01-01

Highlights: → [BMim][MSO 4 ] was studied as solvent to extract toluene from cyclic hydrocarbons. → (Liquid + liquid) equilibrium data were measured at 298.15K and atmospheric pressure. → Selectivity and solute distribution ratio were obtained and compared with literature. → Experimental data were satisfactorily correlated using NRTL and UNIQUAC models. → [BMim][MSO 4 ] can be used as solvent for the studied (liquid + liquid) extraction. - Abstract: In this paper the extraction of toluene from cyclic hydrocarbons (cyclohexane, or methylcyclohexane, or cyclooctane, or cyclohexene) was analyzed by liquid extraction with 1-butyl-3-methylimidazolium methylsulfate ionic liquid, [BMim][MSO 4 ], as solvent. The experimental (liquid + liquid) equilibrium (LLE) data were determined at T = 298.15 K and atmospheric pressure. Solubility curves were obtained by the cloud point method and tie-line compositions were determined by density measurement. An analysis of the influence of different cyclic hydrocarbons on the extraction was performed. The effectiveness of the extraction of toluene from cyclic hydrocarbons was evaluated by means of the solute distribution ratio and selectivity values. The degree of consistency of the experimental LLE data was ascertained using the Othmer-Tobias and Hand equations. The experimental data for the (liquid + liquid) equilibria of the ternary systems were correlated with the Non-Random Two-Liquid (NRTL) and UNIversal QUAsi-Chemical (UNIQUAC) thermodynamic models.

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)

Sustainable treatment of hydrocarbon-contaminated industrial land

OpenAIRE

Cunningham, Colin John

2012-01-01

Land contamination by petroleum hydrocarbons is a widespread and global environmental pollution issue from recovery and refining of crude oil and the ubiquitous use of hydrocarbons in industrial processes and applications. Sustainable treatment of hydrocarbon-contaminated industrial land was considered with reference to seven published works on contaminated railway land including the track ballast, crude oil wastes and contaminated refinery soils. A methodology was developed...

Development of a new method for hydrogen isotope analysis of trace hydrocarbons in natural gas samples

Directory of Open Access Journals (Sweden)

Xibin Wang

2016-12-01

Full Text Available A new method had been developed for the analysis of hydrogen isotopic composition of trace hydrocarbons in natural gas samples by using solid phase microextraction (SPME combined with gas chromatography-isotope ratio mass spectrometry (GC/IRMS. In this study, the SPME technique had been initially introduced to achieve the enrichment of trace content of hydrocarbons with low abundance and coupled to GC/IRMS for hydrogen isotopic analysis. The main parameters, including the equilibration time, extraction temperature, and the fiber type, were systematically optimized. The results not only demonstrated that high extraction yield was true but also shows that the hydrogen isotopic fractionation was not observed during the extraction process, when the SPME device fitted with polydimethylsiloxane/divinylbenzene/carbon molecular sieve (PDMS/DVB/CAR fiber. The applications of SPME-GC/IRMS method were evaluated by using natural gas samples collected from different sedimentary basins; the standard deviation (SD was better than 4‰ for reproducible measurements; and also, the hydrogen isotope values from C1 to C9 can be obtained with satisfying repeatability. The SPME-GC/IRMS method fitted with PDMS/DVB/CAR fiber is well suited for the preconcentration of trace hydrocarbons, and provides a reliable hydrogen isotopic analysis for trace hydrocarbons in natural gas samples.

Hydrocarbon toxicity: an analysis of AAPCC TESS data.

Science.gov (United States)

Cobaugh, Daniel J; Seger, Donna L; Krenzelok, Edward P

2007-01-01

Human hydrocarbon exposures have the potential to cause significant morbidity and mortality. To determine which hydrocarbons were associated with the most severe adverse outcomes, human exposure data reported to American poison information centers were analyzed. Outcome data for single-substance, hydrocarbon exposures reported to the American Association of Poison Control Centers Toxic Exposure Surveillance System from 1994 through 2003 were analyzed. Only cases with definitive medical outcomes were included. Analyses were stratified by five age groups: 59 years. Hazard factors were determined by calculating the sum of the major effects and fatalities for each hydrocarbon category and dividing this by the total number of exposures for that category. To normalize the data, the overall rate of major effects and deaths for each age group was assigned hazard factor value of 1. Hydrocarbon categories with a HF of > or = 1.5 were included in the final analyses. Estimated rates of major effect and fatal outcomes (outcomes/1000 people) were also calculated. 318,939 exposures were analyzed. Exposures to benzene, toluene/xylene, halogenated hydrocarbons, kerosene and lamp oil resulted in the highest hazard factor values. These data demonstrate that hydrocarbons that are absorbed systemically and those with low viscosities are associated with higher hazard factors. The risks associated with hydrocarbons often implicated in abuse by older children and adolescents are also confirmed.

Thermophilic slurry-phase treatment of petroleum hydrocarbon waste sludges

International Nuclear Information System (INIS)

Castaldi, F.J.; Bombaugh, K.J.; McFarland, B.

1995-01-01

Chemoheterotrophic thermophilic bacteria were used to achieve enhanced hydrocarbon degradation during slurry-phase treatment of oily waste sludges from petroleum refinery operations. Aerobic and anaerobic bacterial cultures were examined under thermophilic conditions to assess the effects of mode of metabolism on the potential for petroleum hydrocarbon degradation. The study determined that both aerobic and anaerobic thermophilic bacteria are capable of growth on petroleum hydrocarbons. Thermophilic methanogenesis is feasible during the degradation of hydrocarbons when a strict anaerobic condition is achieved in a slurry bioreactor. Aerobic thermophilic bacteria achieved the largest apparent reduction in chemical oxygen demand, freon extractable oil, total and volatile solid,s and polycyclic aromatic hydrocarbons (PAHs) when treating oily waste sludges. The observed shift with time in the molecular weight distribution of hydrocarbon material was more pronounced under aerobic metabolic conditions than under strict anaerobic conditions. The changes in the hydrocarbon molecular weight distribution, infrared spectra, and PAH concentrations during slurry-phase treatment indicate that the aerobic thermophilic bioslurry achieved a higher degree of hydrocarbon degradation than the anaerobic thermophilic bioslurry during the same time period

The utility of preoperative acth/cortisol ratio for the diagnosis and prognosis of cushing's disease

Directory of Open Access Journals (Sweden)

Alev Selek

2018-01-01

Full Text Available Purpose: Cushing's syndrome (CS is a rare disease having diagnostic difficulties. Many diagnostic tests have been defined but none of these are diagnostic alone. Determination of the cause is another problem which sometimes requires more sophisticated and invasive procedures. Therefore, we aimed to evaluate the utility of pretreatment plasma adrenocorticotropic hormone (ACTH/cortisol ratios in patients with confirmed endogenous CS for the diagnosis and differential diagnosis of CS. Materials and Methods: This retrospective evaluation included 145 patients with the diagnosis of CS, 119 patients with Cushing's disease (CD, and 26 patients with ACTH-independent CS (AICS, in a university hospital. Furthermore, 114 individuals in whom CS diagnosis was excluded with at least one negative screening test were enrolled to the study as control group. The clinical, laboratory, imaging, postsurgical pathologic records and also clinical follow-up data of all patients were evaluated. Results: The median basal ACTH/cortisol ratio of the patients with CD was significantly higher than AICS and controls. A cutoff ACTH/cortisol ratio >2.5 was found to be diagnostic for CD with 82% specificity and 63% sensitivity. Among CD group, patients with recurrent disease had higher preoperative ACTH levels and ACTH/cortisol ratio than patients with sustained remission. Furthermore, these patients had more invasive, atypical, and larger tumors. Conclusion: An ACTH/cortisol ratio >2.5 would be beneficial to diagnose CD together with other diagnostic tests. It is a simple test with no additional cost. Higher ratios might be related with larger, invasive, and atypical adenoma and also might be helpful to predict recurrence.

Degradation of volatile hydrocarbons from steam-classified solid waste by a mixture of aromatic hydrocarbon-degrading bacteria.

Science.gov (United States)

Leahy, Joseph G; Tracy, Karen D; Eley, Michael H

2003-03-01

Steam classification is a process for treatment of solid waste that allows recovery of volatile organic compounds from the waste via steam condensate and off-gases. A mixed culture of aromatic hydrocarbon-degrading bacteria was used to degrade the contaminants in the condensate, which contained approx. 60 hydrocarbons, of which 38 were degraded within 4 d. Many of the hydrocarbons, including styrene, 1,2,4-trimethylbenzene, naphthalene, ethylbenzene, m-/p-xylene, chloroform, 1,3-dichloropropene, were completely or nearly completely degraded within one day, while trichloroethylene and 1,2,3-trichloropropane were degraded more slowly.

Interpretation of diagnostic data: 5. How to do it with simple maths.

Science.gov (United States)

1983-11-01

The use of simple maths with the likelihood ratio strategy fits in nicely with our clinical views. By making the most out of the entire range of diagnostic test results (i.e., several levels, each with its own likelihood ratio, rather than a single cut-off point and a single ratio) and by permitting us to keep track of the likelihood that a patient has the target disorder at each point along the diagnostic sequence, this strategy allows us to place patients at an extremely high or an extremely low likelihood of disease. Thus, the numbers of patients with ultimately false-positive results (who suffer the slings of labelling and the arrows of needless therapy) and of those with ultimately false-negative results (who therefore miss their chance for diagnosis and, possibly, efficacious therapy) will be dramatically reduced. The following guidelines will be useful in interpreting signs, symptoms and laboratory tests with the likelihood ratio strategy: Seek out, and demand from the clinical or laboratory experts who ought to know, the likelihood ratios for key symptoms and signs, and several levels (rather than just the positive and negative results) of diagnostic test results. Identify, when feasible, the logical sequence of diagnostic tests. Estimate the pretest probability of disease for the patient, and, using either the nomogram or the conversion formulas, apply the likelihood ratio that corresponds to the first diagnostic test result. While remembering that the resulting post-test probability or odds from the first test becomes the pretest probability or odds for the next diagnostic test, repeat the process for all the pertinent symptoms, signs and laboratory studies that pertain to the target disorder. However, these combinations may not be independent, and convergent diagnostic tests, if treated as independent, will combine to overestimate the final post-test probability of disease. You are now far more sophisticated in interpreting diagnostic tests than most of

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.

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.

Seawater-cultured Botryococcus braunii for efficient hydrocarbon extraction.

Directory of Open Access Journals (Sweden)

Kenichi Furuhashi

Full Text Available As a potential source of biofuel, the green colonial microalga Botryococcus braunii produces large amounts of hydrocarbons that are accumulated in the extracellular matrix. Generally, pretreatment such as drying or heating of wet algae is needed for sufficient recoveries of hydrocarbons from B. braunii using organic solvents. In this study, the Showa strain of B. braunii was cultured in media derived from the modified Chu13 medium by supplying artificial seawater, natural seawater, or NaCl. After a certain period of culture in the media with an osmotic pressure corresponding to 1/4-seawater, hydrocarbon recovery rates exceeding 90% were obtained by simply mixing intact wet algae with n-hexane without any pretreatments and the results using the present culture conditions indicate the potential for hydrocarbon milking.Seawater was used for efficient hydrocarbon extraction from Botryococcus braunii. The alga was cultured in media prepared with seawater or NaCl. Hydrocarbon recovery rate exceeding 90% was obtained without any pretreatment.

Effect of hydrocarbons on plasma treatment of NOx

Energy Technology Data Exchange (ETDEWEB)

Penetrante, B.M.; Pitz, W.J.; Hsaio, M.C.; Merritt, B.T.; Vogtlin, G.E. [Lawrence Livermore National Lab., CA (United States)

1997-12-31

Lean burn gasoline engine exhausts contain a significant amount of hydrocarbons in the form of propene. Diesel engine exhausts contain little gaseous hydrocarbon; however, they contain a significant amount of liquid-phase hydrocarbons (known as the volatile organic fraction) in the particulates. The objective of this paper is to examine the fate of NO{sub x} when an exhaust gas mixture that contains hydrocarbons is subjected to a plasma. The authors will show that the hydrocarbons promote the oxidation of NO to NO{sub 2}, but not the reduction of NO to N{sub 2}. The oxidation of NO to NO{sub 2} is strongly coupled with the hydrocarbon oxidation chemistry. This result suggests that gas-phase reactions in the plasma alone cannot lead to the chemical reduction of NO{sub x}. Any reduction of NO{sub x} to N{sub 2} can only be accomplished through heterogeneous reactions of NO{sub 2} with surfaces or particulates.

Conversion of Methane to C2 Hydrocarbons and Hydrogen Using a Gliding Arc Reactor

International Nuclear Information System (INIS)

Hu Shuanghui; Wang Baowei; Lv Yijun; Yan Wenjuan

2013-01-01

Methane conversion has been studied using gliding arc plasma in the presence of argon. The process was conducted at atmospheric pressure and ambient temperature. The focus of this research was to develop a process of converting methane to C 2 hydrocarbons and hydrogen. The main parameters, including the CH 4 /Ar mole ratio, the CH 4 flow rate, the input voltage, and the minimum electrode gap, were varied to investigate their effects on methane conversion rate, product distribution, energy consumption, carbon deposit, and reaction stability. The specific energy requirement (SER) was used to express the energy utilization efficiency of the process and provided a practical guidance for optimizing reaction conditions for improving energy efficiency. It was found that the carbon deposition was not conducive to methane conversion, and the gliding arc plasma discharge reached a stable state twelve minutes later. Optimum conditions for methane conversion were suggested. The maximum methane conversion rate of 43.39% was obtained under the optimum conditions. Also, C 2 hydrocarbons selectivity, C 2 hydrocarbons yield, H 2 selectivity, H 2 yield and SER were 87.20%, 37.83%, 81.28%, 35.27%, and 2.09 MJ/mol, respectively.

Magnetic enhancement caused by hydrocarbon migration in the Mawangmiao Oil Field, Jianghan Basin, China

Energy Technology Data Exchange (ETDEWEB)

Liu, Qingsheng; Yang, Tao [Department of Geophysics, China University of Geosciences, Wuhan 430074 (China); Liu, Qingsong [National Oceanography Centre Southampton, University of Southampton, European Way, Southampton SO14 3ZH (United Kingdom); Chan, Lungsang [Department of Earth Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong (China); Xia, Xianghua; Cheng, Tongjin [Wuxi Institute of Petroleum Geology, SNOPEC, Jiangsu Wuxi 214151 (China)

2006-08-15

Magnetic parameters (volume-specific susceptibility k, and hysteresis parameters and ratios) of 47 samples, collected from an oil-producing well (M{sub 36}) and a dry well (M{sub 46}) from the oil-bearing II-You Formation of Paleogene Xingouzui Group in the Mawangmiao Oil Field in China, were measured to address the secondary alteration of iron-bearing minerals associated with hydrocarbon migration. Our results indicated that both k and magnetization (saturation magnetization J{sub s} and saturation isothermal remanent magnetization J{sub rs}) of oil-bearing formation have been dramatically enhanced. Further grain size estimation reveals that the background samples (samples both in M{sub 46} and outside the oil-bearing formation in M{sub 36}) contain coarser-grained magnetic particles (circa 30{mu}m) of detrital origin. In contrast, the alteration of hydrocarbon produces finer-grained (circa 25nm) magnetic particles. The new constraints on grain sizes and its origin of the hydrocarbon-related magnetic particles improve our understanding of the mechanism of formation of these secondary finer-grained particles, even though the precise nature of this process is still unknown. (author)

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.

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...

Can hydrocarbons entrapped in seep carbonates serve as gas geochemistry recorder?

Science.gov (United States)

Blumenberg, Martin; Pape, Thomas; Seifert, Richard; Bohrmann, Gerhard; Schlömer, Stefan

2018-04-01

The geochemistry of seep gases is useful for an understanding of the local petroleum system. Here it was tested whether individual light hydrocarbons in seep gases are representatively entrapped in authigenic carbonates that formed near active seep sites. If applicable, it would be possible to extract geochemical information not only on the origin but also on the thermal maturity of the hydrocarbon source rocks from the gases entrapped in carbonates in the past. Respective data could be used for a better understanding of paleoenvironments and might directly serve as calibration point for, amongst others, petroleum system modeling. For this approach, (sub)-recent seep carbonates from the Black Sea (Paleodnjepr region and Batumi seep area), two sites of the Campeche Knoll region in the Gulf of Mexico, and the Venere mud volcano (Mediterranean Sea) were selected. These seep carbonates derive from sites for which geochemical data on the currently seeping gases exist. During treatment with phosphoric acid, methane and higher hydrocarbons were released from all carbonates, but in low concentrations. Compositional studies demonstrate that the ratio of methane to the sum of higher hydrocarbons (C1/(C2+C3)) is (partly strongly) positively biased in the entrapped gas fraction. δ13C values of C1 were determined for all samples and, for the samples from the Gulf of Mexico and the Mediterranean Sea, also of C2 and C3. The present dataset from six seep sites indicates that information on the seeped methane can be—although with a scatter of several permil—recorded in seep carbonate matrices, but other valuable information like the composition and δ13C of ethane and propane appears to be modified or lost during, for example, enclosure or at an early stage of diagenesis.

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.

Oils; lubricants; paraffin-wax compositions; hydrocarbon condensation products

Energy Technology Data Exchange (ETDEWEB)

1934-04-04

Petroleum hydrocarbons such as gasoline, kerosene, Diesel fuel oil, lubricating-oil, and paraffin wax, and like hydrocarbons such as are obtainable from shale oil and by the hydrogenation of carbonaceous materials, are improved by addition of products obtained by condensing a cyclic hydrocarbon with a saturated dihalogen derivative of an aliphatic hydrocarbon containing less than five carbon atoms. The addition of the condensation products increases the viscosity of the hydrocarbon oils specified, and is particularly useful in the case of lubricating-oils; addition of the condensation products to paraffin wax increases the transparency and adherent properties of the wax, and is useful in the manufacture of moulded articles such as candles; the products may also be used in solid lubricating-compositions.

Imaging fluid/solid interactions in hydrocarbon reservoir rocks.

Science.gov (United States)

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

1993-08-01

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

A method of refining aromatic hydrocarbons from coal chemical production

Energy Technology Data Exchange (ETDEWEB)

Zieborak, K.; Koprowski, A.; Ratajczak, W.

1979-10-01

A method is disclosed for refining aromatic hydrocarbons of coal chemical production by contact of liquid aromatic hydrocarbons and their mixtures with a strongly acid macroporous sulfocationite in the H-form at atmospheric pressure and high temperature. The method is distinguished in that the aromatic hydrocarbons and their mixtures, from which alkali compounds have already been removed, are supplied for refinement with the sulfocationite with simultaneous addition of olefin derivatives of aromatic hydrocarbons, followed by separation of pure hydrocarbons by rectification. Styrene or alpha-methylstyrene is used as the olefin derivatives of the aromatic hydrocarbons. The method is performed in several stages with addition of olefin derivatives of aromatic hydrocarbons at each stage.

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.

Improved Resolution of Hydrocarbon Structures and Constitutional Isomers in Complex Mixtures Using Gas Chromatography-Vacuum Ultraviolet-Mass Spectrometry

Energy Technology Data Exchange (ETDEWEB)

Isaacman, Gabriel [Univ. of California, Berkeley, CA (United States); Wilson, Kevin R. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Chan, Arthur W. H. [Univ. of California, Berkeley, CA (United States); Worton, David R. [Univ. of California, Berkeley, CA (United States). Aerosol Dynamics Inc., Berkeley, CA (United States); Kimmel, Joel R. [Aerodyne Research, Inc., Billerica, MA (United States); Univ. of Colorado, Boulder, CO (United States). Tofwerk AG, Thun (Switzerland); Nah, Theodora [Univ. of California, Berkeley, CA (United States); Hohaus, Thorsten [Aerodyne Research, Inc., Billerica, MA (United States); Gonin, Marc [Tofwerk AG, Thun (Switzerland); Kroll, Jesse H. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Worsnop, Douglas R. [Aerodyne Research, Inc., Billerica, MA (United States); Goldstein, Allen H. [Univ. of California, Berkeley, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

2012-01-30

Understanding the composition of complex hydrocarbon mixtures is important for environmental studies in a variety of fields, but many prevalent compounds cannot be confidently identified using traditional gas chromatography/mass spectrometry (GC/MS) techniques. In this study, we use vacuum-ultraviolet (VUV) ionization to elucidate the structures of a traditionally “unresolved complex mixture” by separating components by GC retention time, t_R, and mass-to-charge ratio, m/z, which are used to determine carbon number, N_C, and the number of rings and double bonds, N_DBE. Constitutional isomers are resolved on the basis of t_R, enabling the most complete quantitative analysis to date of structural isomers in an environmentally relevant hydrocarbon mixture. Unknown compounds are classified in this work by carbon number, degree of saturation, presence of rings, and degree of branching, providing structural constraints. The capabilities of this analysis are explored using diesel fuel, in which constitutional isomer distribution patterns are shown to be reproducible between carbon numbers and follow predictable rules. Nearly half of the aliphatic hydrocarbon mass is shown to be branched, suggesting branching is more important in diesel fuel than previously shown. Lastly, the classification of unknown hydrocarbons and the resolution of constitutional isomers significantly improves resolution capabilities for any complex hydrocarbon mixture.

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

Hydrocarbon-degradation by Isolate Pseudomonas lundensis UTAR FPE2

Directory of Open Access Journals (Sweden)

Adeline, S. Y. Ting

2009-01-01

Full Text Available In this study, the potential of isolate Pseudomonas lundensis UTAR FPE2 as a hydrocarbon degrader was established. Their biodegradation activity was first detected with the formation of clearing zones on Bushnell-Hass agar plates, with the largest diameter observed on plates supplemented with paraffin, followed by mineral oil and petrol. Utilization of hydrocarbon sources were again detected in broth cultures supplemented with similar hydrocarbon substrates, where the mean viable cell count recovered from hydrocarbon-supplemented broth cultures were higher than the initial inoculum except for napthalene. In both tests, the isolate showed higher degradability towards aliphatic hydrocarbon sources, and the least activity towards the aromatic hydrocarbon naphthalene. The isolate P. lundensis UTAR FPE2 (8 log10 cfu/mL also degraded crude diesel sample, with 69% degradation during the first three days. To conclude, this study suggests the potential use of this isolate for bioremediation of hydrocarbon-contaminated environments.

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.

Alkane and polycyclic aromatic hydrocarbons in sediments and benthic invertebrates of the northern Chukchi Sea

Science.gov (United States)

Harvey, H. Rodger; Taylor, Karen A.

2017-10-01

The Hanna Shoal region represents an important northern gateway for transport and deposition in the Chukchi Sea. This study determined the concentration and distribution of organic contaminants (aliphatic hydrocarbon and polycyclic aromatic hydrocarbons, PAHs) in surface sediments from 34 sites across Hanna Shoal. Up to 31 total PAHs, including parent and alkyl homologues were detected with total concentrations ranging from a low of 168 ng g-1 the western flank of Hanna Shoal (station H34) to 1147 ng g-1 at station in Barrow Canyon (station BarC5). Alkyl PAHs were more abundant than parent structures and accounted for 53-64% of the summed concentrations suggesting overall at background levels (< 1600 ng g-1) in sediments. Alkane (C15-C33) hydrocarbons ranged from 4.3 μg g-1 on the southern flank of Hanna shoal to 31 μg g-1 at a northern station. Sediments were often dominated by short chain (C15-C22) alkanes with overall terrestrial aquatic ratios (TAR) for the region averaging 0.20. Based on the ratio of Fl/(Fl+ Py) and BaF/(Baf+BeP) verses (BA/BA+Ch) in sediments, PAHs are largely derived from petrogenic sources with minor amounts of mixed combustion sources. A diversity of PAHs were detected in the northern whelk Neptunea heros foot muscle with total concentrations ranging from 0.14 to 1.5 μg g-1 dry tissue wt. Larger (and presumably older) animals showed higher levels of PAH per unit muscle tissue, suggesting that animals may bioaccumulate PAHs over time, with low but increasing concentrations also present in internal and external eggs. Alkane hydrocarbons were also higher in whelks with distributions similar to that seen in sediments. The mussel Muscularus discors collected in Barrow Canyon showed constrained distributions and substantially lower concentrations of both PAHs and alkanes than the surrounding surface sediments.

Measurements of atmospheric hydrocarbons and biogenic emission fluxes in the Amazon boundary layer

Science.gov (United States)

Zimmerman, P. R.; Greenberg, J. P.; Westberg, C. E.

1988-01-01

Tropospheric mixing ratios of methane, C2-C10 hydrocarbons, and carbon monoxide were measured over the Amazon tropical forest near Manaus, Amazonas, Brazil, in July and August 1985. The measurements, consisting mostly of altitude profiles of these gases, were all made within the atmospheric boundary layer up to an altitude of 1000 m above ground level. Data characterize the diurnal hydrocarbon composition of the boundary layer. Biogenic emissions of isoprene control hydroxyl radical concentrations over the forest. Biogenic emission fluxes of isoprene and terpenes are estimated to be 25,000 micrograms/sq m per day and 5600 micrograms/sq m per day, respectively. This isoprene emission is equivalent to 2 percent of the net primary productivity of the tropical forest. Atmospheric oxidation of biogenic isoprene and terpenes emissions from the Amazon forest may account for daily increases of 8-13 ppb for carbon monoxide in the planetary boundary layer.

Method of preparing and utilizing a catalyst system for an oxidation process on a gaseous hydrocarbon stream

Science.gov (United States)

Berry, David A; Shekhawat, Dushyant; Smith, Mark; Haynes, Daniel

2013-07-16

The disclosure relates to a method of utilizing a catalyst system for an oxidation process on a gaseous hydrocarbon stream with a mitigation of carbon accumulation. The system is comprised of a catalytically active phase deposited onto an oxygen conducting phase, with or without supplemental support. The catalytically active phase has a specified crystal structure where at least one catalytically active metal is a cation within the crystal structure and coordinated with oxygen atoms within the crystal structure. The catalyst system employs an optimum coverage ratio for a given set of oxidation conditions, based on a specified hydrocarbon conversion and a carbon deposition limit. Specific embodiments of the catalyst system are disclosed.

Diagnostics systems for the TBR-E tokamak

International Nuclear Information System (INIS)

Ueda, M.; Ferreira, J.L.; Aso, Y.; Ferreira, J.G.

1992-08-01

A general view of the several diagnostics systems proposed for the TBR-E tokamak is given. This project is a joint undertaking of INPE, USP and UNICAMP plasma laboratories. The requirements for the measurements of the plasma produced parameters are described. Special attention is given for diagnostics used to investigate new physical issues on a low aspect ratio tokamak such as TBR-E. (author)

SPITZER IRAC COLOR DIAGNOSTICS FOR EXTENDED EMISSION IN STAR-FORMING REGIONS

International Nuclear Information System (INIS)

Ybarra, Jason E.; Tapia, Mauricio; Román-Zúñiga, Carlos G.; Lada, Elizabeth A.

2014-01-01

The infrared data from the Spitzer Space Telescope are an invaluable tool for identifying physical processes in star formation. In this study, we calculate the Infrared Array Camera (IRAC) color space of UV fluorescent H 2 and polycyclic aromatic hydrocarbon (PAH) emission in photodissociation regions (PDRs) using the Cloudy code with PAH opacities from Draine and Li. We create a set of color diagnostics that can be applied to study the structure of PDRs and to distinguish between FUV-excited and shock-excited H 2 emission. To test this method, we apply these diagnostics to Spitzer IRAC data of NGC 2316. Our analysis of the structure of the PDR is consistent with previous studies of the region. In addition to UV excited emission, we identify shocked gas that may be part of an outflow originating from the cluster

SPITZER IRAC COLOR DIAGNOSTICS FOR EXTENDED EMISSION IN STAR-FORMING REGIONS

Energy Technology Data Exchange (ETDEWEB)

Ybarra, Jason E.; Tapia, Mauricio; Román-Zúñiga, Carlos G. [Instituto de Astronomía, Universidad Nacional Autónoma de Mexíco, Unidad Académica en Ensenada, Km 103 Carr. Tijuana-Ensenada, 22860 Ensenada BC (Mexico); Lada, Elizabeth A., E-mail: jybarra@astro.unam.mx [Department of Astronomy, University of Florida, 211 Bryant Space Science Center, Gainesville, FL 32611 (United States)

2014-10-20

The infrared data from the Spitzer Space Telescope are an invaluable tool for identifying physical processes in star formation. In this study, we calculate the Infrared Array Camera (IRAC) color space of UV fluorescent H{sub 2} and polycyclic aromatic hydrocarbon (PAH) emission in photodissociation regions (PDRs) using the Cloudy code with PAH opacities from Draine and Li. We create a set of color diagnostics that can be applied to study the structure of PDRs and to distinguish between FUV-excited and shock-excited H{sub 2} emission. To test this method, we apply these diagnostics to Spitzer IRAC data of NGC 2316. Our analysis of the structure of the PDR is consistent with previous studies of the region. In addition to UV excited emission, we identify shocked gas that may be part of an outflow originating from the cluster.

Potential hydrocarbon producing species of Western Ghats, Tamil Nadu, India

Energy Technology Data Exchange (ETDEWEB)

Augustus, G.D.P.S.; Jayabalan, M.; Rajarathinam, K. [Research Centre in Bombay, V.H.N.S.N. College, Virudhunagar (India); Ray, A.K. [Sardar Patel Univ., Anand (India). Dept. of Chemistry; Seiler, G.J. [USDA, ARS, Northern Crop Science Lab., Fargo, ND (United States)

2002-09-01

The decline in the world supplies of hydrocarbons has led to the search for alternate sources of fuel and chemicals. Plant species are potential sources of hydrocarbons. Large-scale screening of plants growing in the Western Ghats, Tamil Nadu, India was conducted to assess the hydrocarbon production and the type of isoprene compound(s) present. Three species contained more than 3% hydrocarbon. Sarcostemma brevistigma had the highest concentration of hydrocarbon with 3.6%. Seven species contained more than 2% of hydrocarbons among the plant species screened. The hydrocarbon fraction of Ficus elastica (leaf) had a gross heat value of 9834 cal/g (41.17 MJ/kg), which is close to the caloric value of fuel oil. Six hydrocarbon fractions contained gross heat values of more than 9000 cal/g (37.68 MJ/kg). Of the 13 species hydrocarbon fraction analysed, seven species contained cis-polyisoprene compounds, while two species contained trans-polyisoprenes. Cis and trans polyisoprenes are potential alternative energy sources for fuel and/or as industrial raw materials. (author)

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)

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.

Seasonal effect on biomarkers of exposure to petroleum hydrocarbons in fish from Kuwait's marine area.

Science.gov (United States)

Beg, M U; Al-Subiai, S N; Al-Jandal, N; Butt, S A; Beg, K R; Al-Husaini, M

2015-11-30

The aquatic biota of the Arabian Gulf deals with exposure to chronic oil pollution, several constituents of which cause induction of Cytochrome P450 1A that serves as a biomarker of AhR ligand exposure. In this study, fluorescent aromatic compounds (FACs) in bile and 7-ethoxyresorufin-o-deethylase (EROD) catalytic activity were determined as a measure of exposure biomarkers in two fish species, yellow fin seabream (Acanthopagrus latus) and tonguesole (Cynoglossus arel) captured from Kuwait Bay and outside the Bay area. FACs in fish bile determined by using fixed-wavelength fluorescence (FF) showed high fluorescence ratios between FF290/335 and FF380/430 indicating predominant exposure to low molecular weight, naphthalene-rich petroleum products (375±91.0 pg ml(-1)). Exposures to benzo(a)pyrene-type high-molecular weight polycyclic aromatic hydrocarbons (PAHs) originating from burnt fuel were also present in appreciable concentration in the bile. The ratio of petrogenic to pyrogenic hydrocarbon was twofold higher in winter compared to summer months in both species. Seasonal effect on EROD was significant in tonguesole in Auha site (Ppollution in Kuwait Bay area. Copyright © 2015 Elsevier Ltd. All rights reserved.

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.

Characterization, Distribution, Sources and Origins of Aliphatic Hydrocarbons from Surface Sediment of Prai Strait, Penang, Malaysia: A Widespread Anthropogenic Input

Directory of Open Access Journals (Sweden)

Mahyar Sakari

2008-07-01

Full Text Available Persistent organic pollutants such as petroleum hydrocarbons are one of the most serious and important class of pollutants that face to many countries including Malaysia. Aliphatic hydrocarbons contain straight chain alkane; derive from anthropogenic and natural sources to the marine environment. The multi-purpose strait of Prai is located in the Northwest of Peninsular Malaysia plays an important economic role in the Southeast Asia. Twenty surface sediment samples were collected using Eckman dredge to measure the concentration and determine the characterization, sources and origins of the aliphatic hydrocarbons in December 2006. Samples (top 4 cm were extracted with Soxhlet, treated with activated copper and subjected to 2 steps column chromatography for purification and fractionation. Alkane fraction injected into Gas Chromatography–Flame Ionization Detector (GC-FID for instrumental analysis. The results showed that total n-alkane concentrations are ranging from 512 to 10770 ng/mg d. w. Carbon Preferences Index (CPI revealed an extreme widespread anthropogenic input and naturally derived (CPI= 0 to 4.88 hydrocarbons in the study area. The ratio of C31/C19 indicated that natural hydrocarbons are generating from terrestrial vascular plants and transferring by rivers. The characteristics of Major Hydrocarbons provided evidences that oil and its derivatives either fresh or degraded are the major contributors of the pollution in the study area. Statistical approaches also confirmed that 85% of study area affected by oil sources of pollution. It is seen that aliphatic hydrocarbons mostly transfer by lateral input to the marine environment than atmospheric movements.

Mid-IR Absorption Cross-Section Measurements of Hydrocarbons

KAUST Repository

Alrefae, Majed Abdullah

2013-05-01

Laser diagnostics are fast-response, non-intrusive and species-specific tools perfectly applicable for studying combustion processes. Quantitative measurements of species concentration and temperature require spectroscopic data to be well-known at combustion-relevant conditions. Absorption cross-section is an important spectroscopic quantity and has direct relation to the species concentration. In this work, the absorption cross-sections of basic hydrocarbons are measured using Fourier Transform Infrared (FTIR) spectrometer, tunable Difference Frequency Generation laser and fixed wavelength helium-neon laser. The studied species are methane, methanol, acetylene, ethylene, ethane, ethanol, propylene, propane, 1-butene, n-butane, n-pentane, n-hexane, and n-heptane. The Fourier Transform Infrared (FTIR) spectrometer is used for the measurements of the absorption cross-sections and the integrated band intensities of the 13 hydrocarbons. The spectral region of the spectra is 2800 – 3400 cm-1 (2.9 – 3.6 μm) and the temperature range is 673 – 1100 K. These valuable data provide huge opportunities to select interference-free wavelengths for measuring time-histories of a specific species in a shock tube or other combustion systems. Such measurements can allow developing/improving chemical kinetics mechanisms by experimentally determining reaction rates. The Difference Frequency Generation (DFG) laser is a narrow line-width, tunable laser in the 3.35 – 3.53 μm wavelength region which contains strong absorption features for most hydrocarbons due to the fundamental C-H vibrating stretch. The absorption cross-sections of propylene are measured at seven different wavelengths using the DFG laser. The temperature range is 296 – 460 K which is reached using a Reflex Cell. The DFG laser is very attractive for kinetic studies in the shock tube because of its fast time response and the potential possibility of making species-specific measurements. The Fixed wavelength

Synthesis of Biokerosene through Electrochemical Hydrogenation of Terpene Hydrocarbons from Turpentine Oil

Directory of Open Access Journals (Sweden)

Tedi Hudaya

2016-12-01

Full Text Available Indonesia possesses great potential for developing renewable resources as alternative fuels. For example, turpentine oil obtained from Pinus merkusii, which contains mostly monoterpene hydrocarbons (C10H16. The oil is highly suitable to be processed for biokerosene or even jet biofuel. It consists of hydrocarbons within the range of C10 to C15. However, it contains insufficient H and thus needs to be upgraded. In the present work, electrochemical hydrogenation was used for upgrading. In the electrochemical cell, stainless steel, silver, and carbon were used alternately for the anode, while copper and silver Raschig rings were used for the cathode. An electrolyte solution of cuprous ammonium formate was utilized not only as a source of H but also to draw the unsaturated hydrocarbons into the aqueous phase. The electrolyte : oil ratio (up to 2:1, electrolyte concentration (between 0.4 and 2 M and reaction time were varied throughout the experiments. The bromine number (unsaturation level of the turpentine oil, which was initially 1,86 (mole Br2/mole, was lowered significantly to 0.69-0.90. Promising increase of smoke point values were observed from 11 mm to 16-24 mm, indicating a higher H content of the processed oil, thus making it suitable as a substitute for petroleum kerosene.

Oil spill aftermath : temporal evaluation of hydrocarbon sources in Guanabara Bay, Brazil

International Nuclear Information System (INIS)

Meniconi, M.F.G.; Massone, C.G.; Scofield, A.L.; Junior, V.J.F.

2005-01-01

The sources of polycyclic aromatic hydrocarbons (PAH) in environmental ecosystems are both natural and anthropogenic. PAHs interact with different types of environmental compartments and are subject to processes that lead to geochemical fates such as physical-chemical transformation, biodegradation and photo-oxidation. This study examined the sources of PAHs in the estuarine sediment of Guanabara Bay, Brazil following an accidental oil spill from an oil refinery in January 2000. The main portion of the oil was carried by tidal currents and wind. It spread over the water and reached islands and shorelines at the north part of the bay. The objective of this study was to determine the likely sources of hydrocarbons in the bay where untreated municipal sewage and industrial wastes are also dumped. Sediment samples were collected using cores and dredges from the intertidal and subtidal regions of the bay, reflecting both affected and unaffected areas. This paper summarized the results of 16 EPA priority PAH and their alkylated homologues from 21 sediment samples collected in the bay 10 days after the oil spill, immediately after the clean up effort, and then 3 years later. The hydrocarbon source was determined using PAH ratios for the samples studied. The highest PAH concentration was observed in 2000 as a result of the petrogenic and pyrolytic contribution to the sediments. 38 refs., 3 tabs., 9 figs

Culture-dependent characterization of hydrocarbon utilizing bacteria ...

African Journals Online (AJOL)

EARNEST

Hydrocarbons interact with the environment and micro- organisms determining the .... it is pertinent to study the community dynamics of hydrocarbon degrading bacteria ... Chikere CB (2013). Application of molecular microbiology techniques in.

Identifying future directions for subsurface hydrocarbon migration research

Science.gov (United States)

Leifer, I.; Clark, J. F.; Luyendyk, B.; Valentine, D.

Subsurface hydrocarbon migration is important for understanding the input and impacts of natural hydrocarbon seepage on the environment. Great uncertainties remain in most aspects of hydrocarbon migration, including some basic mechanisms of this four-phase flow of tar, oil, water, and gas through the complex fracture-network geometry particularly since the phases span a wide range of properties. Academic, government, and industry representatives recently attended a workshop to identify the areas of greatest need for future research in shallow hydrocarbon migration.Novel approaches such as studying temporal and spatial seepage variations and analogous geofluid systems (e.g., geysers and trickle beds) allow deductions of subsurface processes and structures that remain largely unclear. Unique complexities exist in hydrocarbon migration due to its multiphase flow and complex geometry, including in-situ biological weathering. Furthermore, many aspects of the role of hydrocarbons (positive and negative) in the environment are poorly understood, including how they enter the food chain (respiration, consumption, etc.) and “percolate” to higher trophic levels. But understanding these ecological impacts requires knowledge of the emissions' temporal and spatial variability and trajectories.

Distribution, Seasonal Variations and Ecological Risk Assessment of Polycyclic Aromatic Hydrocarbons in Foliar Dust of Nanjing, China.

Science.gov (United States)

Zha, Yan; Zhang, Yinlong; Ma, Zilong; Tang, Jie; Sun, Kai

2018-04-01

Polycyclic aromatic hydrocarbons (PAHs) are of concern for both ecosystem and human health due to their potential teratogenic, carcinogenic, and mutagenic properties. The concentration of ∑ 16 PAHs in foliar dust ranged from 49.4 to 19,018.1 µg kg -1 , with a mean value of 7074.5 µg kg -1 . There were significant seasonal variations in the concentration of ∑ 16 PAHs, with the concentration in winter being almost twice as high as in summer. Similarly, the differences between PAH profiles in different seasons indicated that they had common sources, which were attributed to the combined effect of regional transport and local emissions. The diagnostic ratios of indicator compounds indicated that PAHs detected in foliar dust originated from a mixture of gasoline vehicle emissions, biomass, and coal combustion in Nanjing. According to the ecological risk classification of ∑ 16 PAHs, the ecological risk caused by PAHs was high since the value of RQ ∑16PAHs(MPCs) was ≥ 1 and RQ ∑16PAHs(NCs) were ≥ 800. The mean values for RQ∑ 16 PAHs (MPCs) and RQ∑ 16 PAHs (NCs) were 14.8 and 2368.9, which indicated a relatively high ecological risks of PAHs in foliar dust in Nanjing.

Bio-accumulation of Polycyclic Aromatic Hydrocarbons in the Grey Mangrove (Avicennia marina along Arabian Gulf, Saudi Coast

Directory of Open Access Journals (Sweden)

Orif Mohammed

2018-04-01

Full Text Available The Arabian Gulf is considered as one of the most important sources for the crude oil all over the world. Due to the vast oil exploration and exploitation, huge amounts of organic pollutants infiltrate to the gulf. An important class of organic pollutants is polycyclic aromatic hydrocarbons (PAHs. One of the marine habitats in Arabian Gulf area is the mangrove stands, that are undoubtedly impacted by all anthropogenic factors like oil industries and sewage discharge. In the monitoring framework for mangrove ecosystem along Saudi coasts, nine mangrove stands were examined for the accumulation of PAHs in the Arabian Gulf coast. PAHs were measured using Gas Chromatography-Mass Spectrometry. The mean values detected for total PAHs in mangrove sediments, roots and leaf were 105.39, 680.0 and 282.4 ng/g, respectively. The trend of total PAHs concentrations in all sites showed the descending order: roots > leaf > sediments. Despite the sandy nature and low organic carbon contents of the mangrove sediments, moderate values of PAHs were detected in the major sites. PAH bio-accumulation factors for roots are higher than that in leaf. The diagnostic ratios revealed that the sources of PAHs are mainly pyrogenic, except for Damam and Damam Port that were found to be petrogenic.

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...

Enhanced bioremediation of hydrocarbon-contaminated soil using pilot-scale bioelectrochemical systems

International Nuclear Information System (INIS)

Lu, Lu; Yazdi, Hadi; Jin, Song; Zuo, Yi; Fallgren, Paul H.; Ren, Zhiyong Jason

2014-01-01

Highlights: • Pilot bioelectrochemical system showed high-performance hydrocarbon remediation. • Radius of influence characterization demonstrated system efficacy. • Current serves as degradation indicator. - Abstract: Two column-type bioelectrochemical system (BES) modules were installed into a 50-L pilot scale reactor packed with diesel-contaminated soils to investigate the enhancement of passive biodegradation of petroleum compounds. By using low cost electrodes such as biochar and graphite granule as non-exhaustible solid-state electron acceptors, the results show that 82.1–89.7% of the total petroleum hydrocarbon (TPH) was degraded after 120 days across 1–34 cm radius of influence (ROI) from the modules. This represents a maximum of 241% increase of biodegradation compared to a baseline control reactor. The current production in the BESs correlated with the TPH removal, reaching the maximum output of 70.4 ± 0.2 mA/m 2 . The maximum ROI of the BES, deducting influence from the baseline natural attenuation, was estimated to be more than 90 cm beyond the edge of the reactor (34 cm), and exceed 300 cm should a non-degradation baseline be used. The ratio of the projected ROI to the radius of BES (ROB) module was 11–12. The results suggest that this BES can serve as an innovative and sustainable technology for enhanced in situ bioremediation of petroleum hydrocarbons in large field scale, with additional benefits of electricity production and being integrated into existing field infrastructures

Enhanced bioremediation of hydrocarbon-contaminated soil using pilot-scale bioelectrochemical systems

Energy Technology Data Exchange (ETDEWEB)

Lu, Lu; Yazdi, Hadi [Department of Civil, Environmental, and Architectural Engineering, University of Colorado Boulder, Boulder, CO (United States); Jin, Song [Department of Civil and Architectural Engineering, University of Wyoming, Laramie, WY (United States); Zuo, Yi [Chevron Energy Technology Company, San Ramon, CA (United States); Fallgren, Paul H. [Department of Civil Engineering, University of Colorado Denver, Denver, CO (United States); Ren, Zhiyong Jason, E-mail: jason.ren@colorado.edu [Department of Civil, Environmental, and Architectural Engineering, University of Colorado Boulder, Boulder, CO (United States); Department of Civil Engineering, University of Colorado Denver, Denver, CO (United States)

2014-06-01

Highlights: • Pilot bioelectrochemical system showed high-performance hydrocarbon remediation. • Radius of influence characterization demonstrated system efficacy. • Current serves as degradation indicator. - Abstract: Two column-type bioelectrochemical system (BES) modules were installed into a 50-L pilot scale reactor packed with diesel-contaminated soils to investigate the enhancement of passive biodegradation of petroleum compounds. By using low cost electrodes such as biochar and graphite granule as non-exhaustible solid-state electron acceptors, the results show that 82.1–89.7% of the total petroleum hydrocarbon (TPH) was degraded after 120 days across 1–34 cm radius of influence (ROI) from the modules. This represents a maximum of 241% increase of biodegradation compared to a baseline control reactor. The current production in the BESs correlated with the TPH removal, reaching the maximum output of 70.4 ± 0.2 mA/m{sup 2}. The maximum ROI of the BES, deducting influence from the baseline natural attenuation, was estimated to be more than 90 cm beyond the edge of the reactor (34 cm), and exceed 300 cm should a non-degradation baseline be used. The ratio of the projected ROI to the radius of BES (ROB) module was 11–12. The results suggest that this BES can serve as an innovative and sustainable technology for enhanced in situ bioremediation of petroleum hydrocarbons in large field scale, with additional benefits of electricity production and being integrated into existing field infrastructures.

Continuous flow isotope ratio mass spectrometer (CF-IRMS) and its applications in hydrocarbon research and exploration

International Nuclear Information System (INIS)

Kalpana, G.; Patil, D.J.; Kumar, B.

2004-01-01

Stable isotope ratio mass spectrometers have been widely used to determine the isotopic ratios of light elements such as hydrogen, carbon, nitrogen, oxygen and sulphur. Continuous Flow Isotope Ratio Mass Spectrometry (CFIRMS) provides reliable data on nanomole amount of sample gas without the need for cryogenic trapping using cold fingers as in dual inlet isotope ratio mass spectrometer. High sample throughput is achieved as the system is configured with automated sample preparation devices and auto samplers. This paper presents a brief description of CFIRMS exploration

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...

Polycyclic’ Aromatic Hydrocarbon Induced Intracellular Signaling and Lymphocyte Apoptosis

DEFF Research Database (Denmark)

Schneider, Alexander M.

The aryl hydrocarbon (dioxin) receptor (AhR) is a transcription factor possessing high affinity to potent environmental pollutants, polycyclic aromatic hydrocarbons (PAH) and related halogenated hydrocarbons (e.g. dioxins). Numerous research attribute toxicity of these compounds to the receptor...

Analytical system for stable carbon isotope measurements of low molecular weight (C2-C6 hydrocarbons

Directory of Open Access Journals (Sweden)

T. Röckmann

2011-06-01

Full Text Available We present setup, testing and initial results from a new automated system for stable carbon isotope ratio measurements on C2 to C6 atmospheric hydrocarbons. The inlet system allows analysis of trace gases from air samples ranging from a few liters for urban samples and samples with high mixing ratios, to many tens of liters for samples from remote unpolluted regions with very low mixing ratios. The centerpiece of the sample preparation is the separation trap, which is used to separate CO2 and methane from the compounds of interest. The main features of the system are (i the capability to sample up to 300 l of air, (ii long term (since May 2009 operational δ13C accuracy levels in the range 0.3–0.8 ‰ (1-σ, and (iii detection limits of order 1.5–2.5 ngC (collected amount of substance for all reported compounds. The first application of this system was the analysis of 21 ambient air samples taken during 48 h in August 2009 in Utrecht, the Netherlands. Results obtained are generally in good agreement with those from similar urban ambient air studies. Short sample intervals allowed by the design of the instrument help to illustrate the complex diurnal behavior of hydrocarbons in an urban environment, where diverse sources, dynamical processes, and chemical reactions are present.

Method for production of unsaturated gaseous hydrocarbons, particularly ethylene, and of aromatic hydrocarbons, adapted as motor fuels

Energy Technology Data Exchange (ETDEWEB)

1952-10-24

A method is described for the production of unsaturated gaseous hydrocarbons, in particular of ethylene, and of aromatic hydrocarbons from hydrocarbon oils or from fractions of the same, characterized by the fact that the raw materials are brought into contact with porous, inert substances in the form of fine distribution or of pieces at a temperature of above 500 and in particular from 600 to about 700/sup 0/C and with a traversing speed of from 0.3 up to about 3.0 volumetric parts, preferably up to 1.5 volumetric parts of raw material per volumetric part of the chamber and per hour.

Patterns and sources of particle-phase aliphatic and polycyclic aromatic hydrocarbons in urban and rural sites of western Greece

Science.gov (United States)

Kalaitzoglou, Maria; Terzi, Eleni; Samara, Constantini

Particle-bound aliphatic and polycyclic aromatic hydrocarbons (AHs and PAHs, respectively) were determined in the ambient air of the Eordea basin, in western Greece, where intensive coal burning for power generation takes place. Thirteen PAHs, n-alkanes (C 14-C 35), hopanes, and isoprenoid hydrocarbons (pristane and phytane) were determined in the total suspended particles collected from the atmosphere of four sites within the basin receiving potential impacts from various sources, such as fly ash, coal mining, automobile traffic, domestic heating, and agricultural or refuse burning. The same organic species were also determined in the fly ash generated in power stations, and in particulate emissions from open burning of biomass (dry corn leaves) and refuse burning. Organic particle sources were resolved using concentration diagnostic ratios and factor analysis (FA). A multivariate statistical receptor model (Absolute Principal Component Analysis, APCA) was finally employed to estimate the contribution of identified sources to the measured concentrations of organic pollutants. Four major sources for ambient PAHs and AHs were identified displaying variable contribution in different sites: (a) fossil fuel combustion, (b) biogenic emissions, (c) refuse burning, and (d) oil residues. Fuel combustion was the major source of ambient PAHs and an important source of n-alkanes in the range C 21-C 28. Oil residues were found to be the major source of low molecular weight n-alkanes (particularly the C 14-C 16), and an important source of pristane, phytane and UCM. Biogenic sources were primarily responsible for the high molecular weight n-alkanes explaining almost the entire concentration levels of homologues >C 32. Biomass burning was particularly important for the C 23-C 26n-alkanes. Despite the vicinity of certain sampling sites to power stations, coal fly ash was not identifiable as a source for ambient PAHs and AHs.

Titan's Carbon Isotopic Ratio: A Clue To Atmospheric Evolution?

Science.gov (United States)

Nixon, C. A.; Jennings, D. E.; Romani, P. N.; Jolly, A.; Teanby, N. A.; Irwin, P. G.; Bézard, B.; Vinatier, S.; Coustenis, A.; Flasar, F. M.

2009-12-01

In this presentation we describe the latest results to come from Cassini CIRS and ground-based telescopic measurements of Titan's 12C/13C ratio in atmospheric molecules, focusing on hydrocarbons. Previously, the Huygens GCMS instrument measured 12CH4/13CH4 to be 82±1 (Niemann et al., Nature, 438, 779-784, 2005), substantially and significantly lower than the VPDB inorganic Earth standard of 89.4. It is also at odds with measurements for the giant planets. Cassini CIRS infrared spectra have confirmed this enhancement in 13CH4, but also revealed that the ratio in ethane, the major photochemical product of methane photolysis, does not appear enhanced (90±7) (Nixon et al.. Icarus, 195, 778-791, 2008) and is compatible with the terrestrial and combined giant planet value (88±7, Sada et al., Ap. J., 472, p. 903-907, 1996). Recently-published results from spectroscopy using the McMath-Pierce telescope at Kitt Pitt (Jennings et al., JCP, 2009, in press) have confirmed this deviation between methane and ethane, and an explanation has been proposed. This invokes a kinetic isotope effect (KIE) in the abstraction of methane by ethynyl, a major ethane formation pathway, to preferentially partition 12C into ethane and leave an enhancement in atmospheric 13CH4 relative to the incoming flux from the reservoir. Modeling shows that a steady-state solution exists where the 12C/13C methane is decreased from the reservoir value by exactly the KIE factor (the ratio of 12CH4 to 13CH4 abstraction reaction rates): which is plausibly around 1.08, very close to the observed amount. However, a second solution exists in which we are observing Titan about ~1 methane lifetime after a major injection of methane into the atmosphere which is rapidly being eliminated. Updated measurements by Cassini CIRS of both the methane and ethane 12C/13C ratios will be presented, along with progress in interpreting this ratio. In addition, we summarize the 12C/13C measurements by CIRS in multiple other Titan

Catalytic conversion of alcohols to hydrocarbons with low benzene content

Energy Technology Data Exchange (ETDEWEB)

Narula, Chaitanya K.; Davison, Brian H.; Keller, Martin

2016-03-08

A method for converting an alcohol to a hydrocarbon fraction having a lowered benzene content, the method comprising: converting said alcohol to a hydrocarbon fraction by contacting said alcohol, under conditions suitable for converting said alcohol to said hydrocarbon fraction, with a metal-loaded zeolite catalyst catalytically active for converting said alcohol to said hydrocarbon fraction, and contacting said hydrocarbon fraction with a benzene alkylation catalyst, under conditions suitable for alkylating benzene, to form alkylated benzene product in said hydrocarbon fraction. Also described is a catalyst composition useful in the method, comprising a mixture of (i) a metal-loaded zeolite catalyst catalytically active for converting said alcohol to said hydrocarbon, and (ii) a benzene alkylation catalyst, in which (i) and (ii) may be in a mixed or separated state. A reactor for housing the catalyst and conducting the reaction is also described.

Catalytic conversion of alcohols to hydrocarbons with low benzene content

Energy Technology Data Exchange (ETDEWEB)

Narula, Chaitanya K.; Davison, Brian H.; Keller, Martin

2016-09-06

A method for converting an alcohol to a hydrocarbon fraction having a lowered benzene content, the method comprising: converting said alcohol to a hydrocarbon fraction by contacting said alcohol, under conditions suitable for converting said alcohol to said hydrocarbon fraction, with a metal-loaded zeolite catalyst catalytically active for converting said alcohol to said hydrocarbon fraction, and contacting said hydrocarbon fraction with a benzene alkylation catalyst, under conditions suitable for alkylating benzene, to form alkylated benzene product in said hydrocarbon fraction. Also described is a catalyst composition useful in the method, comprising a mixture of (i) a metal-loaded zeolite catalyst catalytically active for converting said alcohol to said hydrocarbon, and (ii) a benzene alkylation catalyst, in which (i) and (ii) may be in a mixed or separated state. A reactor for housing the catalyst and conducting the reaction is also described.

Methods for reformation of gaseous hydrocarbons using electrical discharge

KAUST Repository

Cha, Min Suk

2017-02-16

Methods for the reformation of gaseous hydrocarbons are provided. The methods can include forming a bubble containing the gaseous hydrocarbon in a liquid. The bubble can be generated to pass in a gap between a pair of electrodes, whereby an electrical discharge is generated in the bubble at the gap between the electrodes. The electrodes can be a metal or metal alloy with a high melting point so they can sustain high voltages of up to about 200 kilovolts. The gaseous hydrocarbon can be combined with an additive gas such as molecular oxygen or carbon dioxide. The reformation of the gaseous hydrocarbon can produce mixtures containing one or more of H2, CO, H2O, CO2, and a lower hydrocarbon such as ethane or ethylene. The reformation of the gaseous hydrocarbon can produce low amounts of CO2 and H2O, e.g. about 15 mol-% or less.

Methods for reformation of gaseous hydrocarbons using electrical discharge

KAUST Repository

Cha, Min; Zhang, Xuming

2017-01-01

Methods for the reformation of gaseous hydrocarbons are provided. The methods can include forming a bubble containing the gaseous hydrocarbon in a liquid. The bubble can be generated to pass in a gap between a pair of electrodes, whereby an electrical discharge is generated in the bubble at the gap between the electrodes. The electrodes can be a metal or metal alloy with a high melting point so they can sustain high voltages of up to about 200 kilovolts. The gaseous hydrocarbon can be combined with an additive gas such as molecular oxygen or carbon dioxide. The reformation of the gaseous hydrocarbon can produce mixtures containing one or more of H2, CO, H2O, CO2, and a lower hydrocarbon such as ethane or ethylene. The reformation of the gaseous hydrocarbon can produce low amounts of CO2 and H2O, e.g. about 15 mol-% or less.

Session 2: economic and environmental aspects of the different sources of hydrocarbons

International Nuclear Information System (INIS)

Susbielles, G.

2006-01-01

Here are given the summaries of the speeches of Mr Bernard Montaron (Schlumberger): the petroleum recovery ratios: a technical challenge for the energetic stake; of Mr Xavier Preel (Total): the non conventional petroleums; of Mr Guy de Kort (Shell): gas to liquids; and of Mrs Nathalie Alazard (IFP): the fuels coming from biomass. All these speeches have been presented at the AFTP petroleum yearly days (12-13 October 2005) during the session 2 concerning the economical and environmental aspects of the different sources of hydrocarbons. (O.M.)

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

Degradation of petroleum hydrocarbons in a laboratory aquifer column

International Nuclear Information System (INIS)

Billowits, M.; Whyte, L.; Greer, C.; Ramsay, J.

1998-01-01

One of the primary mechanisms for eliminating hydrocarbon pollutants from the environment is degradation of hydrocarbons by indigenous microorganisms. This report describes a study in which samples from a petroleum polluted shallow aquifer in the Yukon were used which contained a hundred times greater concentration of psychrotropic bacteria than mesophilic bacteria. Results showed a maximum degradation of 47 per cent of the total petroleum hydrocarbon in columns which simulated the aquifer conditions and to which nutrients were added. It was concluded that although in this case bioaugmentation of the columns with a psychrotropic hydrocarbon-degrading consortium increased microbial numbers, total petroleum hydrocarbon degradation was not much greater than could be achieved by remediation with nutrients alone

Hydrocarbons in Argentina: networks, territories, integration

International Nuclear Information System (INIS)

Carrizo, S.C.

2003-12-01

Argentinean hydrocarbons networks have lived a huge reorganizing the structure, after the State reform in the 90's. Activities deregulation and the privatization of YPF and Gas del Estado forced the sector re-concentration, since then dominated by foreign companies, leaded by Repsol YPF. The hydrocarbons federalization contributed to the weakening and un-capitalization loss of wealth of the State. These changes resulted in an increase of the hydrocarbons production allowing to achieve the self-supply. Nevertheless, the expansion of internal networks has not been large enough to ensure the coverage of new requirements. Besides, several infrastructures have been built up to join external markets. National networks are connected to those of near neighboring countries. This integration is an opportunity for the 'South Cone' countries to enhance their potentials. In the country, hydrocarbons territories undergo the reorganizing the structure effects (unemployment, loss of territorial identity, etc). With many difficulties and very different possibilities, those territories, like Comodoro Rivadavia, Ensenada et and Bahia Blanca, look for their re-invention. (author)

Distributions of nitrated polycyclic aromatic hydrocarbons in the sediment of Osaka Bay, Japan.

Science.gov (United States)

Uno, Seiichi; Tanaka, Hiroyuki; Kokushi, Emiko; Bacolod, Eugene T; Koyama, Jiro

2017-11-30

The distributions of 15 nitrated polycyclic aromatic hydrocarbons (NPAHs) in sediments collected at 44 sites throughout Osaka Bay, Japan were examined. The highest total NPAHs, with a concentration of 1949ng/kg dry weight, were detected near the city of Amagasaki. Some sites near the cities of Osaka, Kishiwada, sand Sakai registered ng/kg levels of NPAHs, but individual NPAH concentrations were relatively lower than those in previous studies. The sources were estimated using principal component analysis, and NPAHs were derived from exhaust gases of automobiles and industries at some sites. However, our results suggest that it is difficult to estimate the source, especially in coastal areas near big cities and large industrial areas, because the generation pathways between parent polycyclic aromatic hydrocarbons (PAHs) and nitrated PAHs are slightly different, and the ratio of PAHs and NPAHs could not be accurately reflect the characters of sources in sediments especially at coastal areas with large-scale industrial zones. Copyright © 2017 Elsevier Ltd. All rights reserved.

Bioremediation in soil contaminated with hydrocarbons in Colombia.

OpenAIRE

María Alejandra Trujillo Toro; Juan Fernando Ramírez Quirama

2012-01-01

This study analyzes bioremediation processes of hydrocarbon contaminated soils in Colombia as a sustainable alternative to the deterioration of environmental quality by hydrocarbon spillage. According to national and international environmental law, all waste contaminated with hydrocarbons is considered dangerous waste, and therefore it cannot be released in the ground, water or be incinerated. Such legislation has motivated companies around the world to implement treatment processes for cont...

Hydrocarbon productivities in different Botryococcus strains: comparative methods in product quantification.

Science.gov (United States)

Eroglu, Ela; Okada, Shigeru; Melis, Anastasios

2011-08-01

Six different strains of the green microalgae Botryococcus belonging to the A-race or B-race, accumulating alkadiene or botryococcene hydrocarbons, respectively, were compared for biomass and hydrocarbon productivities. Biomass productivity was assessed gravimetrically upon strain growth in the laboratory under defined conditions. Hydrocarbon productivities were measured by three different and independent experimental approaches, including density equilibrium of the intact cells and micro-colonies, spectrophotometric analysis of hydrocarbon extracts, and gravimetric quantitation of eluted hydrocarbons. All three hydrocarbon-quantitation methods yielded similar results for each of the strains examined. The B-race microalgae Botryococcus braunii var. Showa and Kawaguchi-1 constitutively accumulated botryococcene hydrocarbons equivalent to 30% and 20%, respectively, of their overall biomass. The A-race microalgae Botryococcus braunii, varieties Yamanaka, UTEX 2441 and UTEX LB572 constitutively accumulated alkadiene hydrocarbons ranging from 14% to 13% and 10% of their overall biomass, respectively. Botryococcus sudeticus (UTEX 2629), a morphologically different green microalga, had the lowest hydrocarbon accumulation, equal to about 3% of its overall biomass. Results validate the density equilibrium and spectrophotometric analysis methods in the quantitation of botryococcene-type hydrocarbons. These analytical advances will serve in the screening and selection of B. braunii and of other microalgae in efforts to identify those having a high hydrocarbon content for use in commercial applications.

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.

Design Features of the Neutral Particle Diagnostic System for the ITER Tokamak

Science.gov (United States)

Petrov, S. Ya.; Afanasyev, V. I.; Melnik, A. D.; Mironov, M. I.; Navolotsky, A. S.; Nesenevich, V. G.; Petrov, M. P.; Chernyshev, F. V.; Kedrov, I. V.; Kuzmin, E. G.; Lyublin, B. V.; Kozlovski, S. S.; Mokeev, A. N.

2017-12-01

The control of the deuterium-tritium (DT) fuel isotopic ratio has to ensure the best performance of the ITER thermonuclear fusion reactor. The diagnostic system described in this paper allows the measurement of this ratio analyzing the hydrogen isotope fluxes (performing neutral particle analysis (NPA)). The development and supply of the NPA diagnostics for ITER was delegated to the Russian Federation. The diagnostics is being developed at the Ioffe Institute. The system consists of two analyzers, viz., LENPA (Low Energy Neutral Particle Analyzer) with 10-200 keV energy range and HENPA (High Energy Neutral Particle Analyzer) with 0.1-4.0MeV energy range. Simultaneous operation of both analyzers in different energy ranges enables researchers to measure the DT fuel ratio both in the central burning plasma (thermonuclear burn zone) and at the edge as well. When developing the diagnostic complex, it was necessary to account for the impact of several factors: high levels of neutron and gamma radiation, the direct vacuum connection to the ITER vessel, implying high tritium containment, strict requirements on reliability of all units and mechanisms, and the limited space available for accommodation of the diagnostic hardware at the ITER tokamak. The paper describes the design of the diagnostic complex and the engineering solutions that make it possible to conduct measurements under tokamak reactor conditions. The proposed engineering solutions provide a safe—with respect to thermal and mechanical loads—common vacuum channel for hydrogen isotope atoms to pass to the analyzers; ensure efficient shielding of the analyzers from the ITER stray magnetic field (up to 1 kG); provide the remote control of the NPA diagnostic complex, in particular, connection/disconnection of the NPA vacuum beamline from the ITER vessel; meet the ITER radiation safety requirements; and ensure measurements of the fuel isotopic ratio under high levels of neutron and gamma radiation.

Characterization of hydrocarbons, halocarbons and carbonyls in the atmosphere of Hong Kong.

Science.gov (United States)

Guo, H; Lee, S C; Louie, P K K; Ho, K F

2004-12-01

Ambient air quality measurements of 156 species including 39 alkanes, 32 alkenes, 2 alkynes, 24 aromatic hydrocarbons, 43 halocarbons and 16 carbonyls, were carried out for 120 air samples collected at two sampling stations (CW and TW) in 2001 throughout Hong Kong. Spatial variations of volatile organic compounds (VOCs) in the atmosphere were investigated. Levels of most alkanes and alkenes at TW site were higher than that at the CW site, while the BTEX concentrations at the two sites were close. The BTEX ratios at CW and TW were 1.6:10.1:1.0:1.6 and 2.1:10.8:1.0:2.0, respectively. For major halogenated hydrocarbons, the mean concentrations of chloromethane, CFCs 12 and 22 did not show spatial variations at the two sites. However, site-specific differences were observed for trichloroethene and tetrachloroethene. Furthermore, there were no significant differences for carbonyls such as formaldehyde, acetaldehyde and acetone between the two sites. The levels of selected hydrocarbons in winter were 1-5 times that in summer. There were no common seasonal trends for carbonyls in Hong Kong. The ambient level of formaldehyde, the most abundant carbonyl, was higher in summer. However, levels of acetaldehyde, acetone and benzaldehyde in winter were 1.6-3.8 times that in summer. The levels of CFCs 11 and 12, and chloromethane in summer were higher than that in winter. Strong correlation of most hydrocarbons with propene and n-butane suggested that the primary contributors of hydrocarbons were vehicular emissions in Hong Kong. In addition, gasoline evaporation, use of solvents, leakage of liquefied petroleum gas (LPG), natural gas leakage and other industrial emissions, and even biogenic emissions affected the ambient levels of hydrocarbons. The sources of halocarbons were mainly materials used in industrial processes and as solvents. Correlation analysis suggested that photochemical reactions made significant contributions to the ambient levels of carbonyls in summer whereas

Italian Advisory Board: sFlt-1/PlGF ratio and preeclampsia, state of the art and developments in diagnostic, therapeutic and clinical management.

Science.gov (United States)

Di Martino, Daniela; Cetin, Irene; Frusca, Tiziana; Ferrazzi, Enrico; Fuse', Federica; Gervasi, Maria Teresa; Plebani, Mario; Todros, Tullia

2016-11-01

Extensive research has been published, showing the usefulness of angiogenic markers in both diagnosis and subsequent prediction and management of preeclampsia and placenta-related disorders. Recent evidence provides a helpful cut off for the Elecsys ratio sFlt-1 to PlGF, that predicts preeclampsia development in women with sign and symptoms, before its clinical onset in the short term. In Europe, no accordance exists for the use of such kind of test in clinical practice; only German guidelines have recently taken it into account, as a diagnostic aid for preeclampsia, in conjunction with other clinical findings. This panel of Italian experts recently met, in order to review the literature and to promote the evaluation of the clinical utility of sFlt-1/PlGF ratio at the Italian country level, as regards: prediction of preeclampsia during the first trimester, prediction or exclusion of new onset or recurrence in patients with risk factors for preeclampsia, triage of patients suffering from gestational hypertension, evaluation of disease severity, prediction of adverse maternal and fetal outcomes. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Radiation-induced volatile hydrocarbon production in platelets

International Nuclear Information System (INIS)

Radha, E.; Vaishnav, Y.N.; Kumar, K.S.; Weiss, J.F.

1989-01-01

Generation of volatile hydrocarbons (ethane, pentane) as a measure of lipid peroxidation was followed in preparations from platelet-rich plasma irradiated in vitro. The hydrocarbons in the headspace of sealed vials containing irradiated and nonirradiated washed platelets, platelet-rich plasma, or platelet-poor plasma increased with time. The major hydrocarbon, pentane, increased linearly and significantly with increasing log radiation dose, suggesting that reactive oxygen species induced by ionizing radiation result in lipid peroxidation. Measurements of lipid peroxidation products may give an indication of suboptimal quality of stored and/or irradiated platelets

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.

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.

Improved resolution of hydrocarbon structures and constitutional isomers in complex mixtures using Gas Chromatography-Vacuum Ultraviolet-Mass Spectrometry (GC-VUV-MS)

Energy Technology Data Exchange (ETDEWEB)

Aerosol Dynamics Inc; Aerodyne Research, Inc.,; Tofwerk AG, Thun; Isaacman, Gabriel; Wilson, Kevin R.; Chan, Arthur W. H.; Worton, David R.; Kimmel, Joel R.; Nah, Theodora; Hohaus, Thorsten; Gonin, Marc; Kroll, Jesse H.; Worsnop, Doug R.; Goldstein, Allen H.

2011-09-13

Understanding the composition of complex hydrocarbon mixtures is important for environmental studies in a variety of fields, but many prevalent compounds cannot be confidently identified using traditional gas chromatography-mass spectrometry (GC-MS) techniques. This work uses vacuum-ultraviolet (VUV) ionization to elucidate the structures of a traditionally"unresolved complex mixture" by separating components by GC retention time, tR, and mass-to-charge ratio, m/Q, which are used to determine carbon number, NC, and the number of rings and double bonds, NDBE. Constitutional isomers are resolved based on tR, enabling the most complete quantitative analysis to date of structural isomers in an environmentally-relevant hydrocarbon mixture. Unknown compounds are classified in this work by carbon number, degree of saturation, presence of rings, and degree of branching, providing structural constraints. The capabilities of this analysis are explored using diesel fuel, in which constitutional isomer distribution patterns are shown to be reproducible between carbon numbers and follow predictable rules. Nearly half of the aliphatic hydrocarbon mass is shown to be branched, suggesting branching is more important in diesel fuel than previously shown. The classification of unknown hydrocarbons and the resolution of constitutional isomers significantly improves resolution capabilities for any complex hydrocarbon mixture.

GC×GC measurements of C7-C11 aromatic and n-alkane hydrocarbons on Crete, in air from Eastern Europe during the MINOS campaign

Directory of Open Access Journals (Sweden)

X. Xu

2003-01-01

Full Text Available During the Mediterranean Intensive Oxidant Study (MINOS campaign in August 2001 gas-phase organic compounds were measured using comprehensive two-dimensional gas chromatography (GCxGC at the Finokalia ground station, Crete. In this paper, C7-C11 aromatic and n-alkane measurements are presented and interpreted. The mean mixing ratios of the hydrocarbons varied from 1±1 pptv (i-propylbenzene to 43±36 pptv (toluene. The observed mixing ratios showed strong day-to-day variations and generally higher levels during the first half of the campaign. Mean diel profiles showed maxima at local midnight and late morning, and minima in the early morning and evening. Results from analysis using a simplified box model suggest that both the chemical sink (i.e. reaction with OH and the variability of source strengths were the causes of the observed variations in hydrocarbon mixing ratios. The logarithms of hydrocarbon concentrations were negatively correlated with the OH concentrations integral over a day prior to the hydrocarbon measurements. Slopes of the regression lines derived from these correlations for different compounds are compared with literature rate constants for their reactions with OH. The slopes for most compounds agree reasonably well with the literature rate constants. A sequential reaction model has been applied to the interpretation of the relationship between ethylbenzene and two of its potential products, i.e. acetophenone and benzeneacetaldehyde. The model can explain the good correlation observed between [acetophenone]/[ethylbenzene] and [benzeneacetaldehyde]/[ethylbenzene]. The model results and field measurements suggest that the reactivity of benzeneacetaldehyde may lie between those of acetophenone and ethylbenzene and that the ratio between yields of acetophenone and benzeneacetaldehyde may be up to 28:1. Photochemical ages of trace gases sampled at Finokalia during the campaign are estimated using the sequential reaction model and

Hydrodeoxygenation processes: advances on catalytic transformations of biomass-derived platform chemicals into hydrocarbon fuels.

Science.gov (United States)

De, Sudipta; Saha, Basudeb; Luque, Rafael

2015-02-01

Lignocellulosic biomass provides an attractive source of renewable carbon that can be sustainably converted into chemicals and fuels. Hydrodeoxygenation (HDO) processes have recently received considerable attention to upgrade biomass-derived feedstocks into liquid transportation fuels. The selection and design of HDO catalysts plays an important role to determine the success of the process. This review has been aimed to emphasize recent developments on HDO catalysts in effective transformations of biomass-derived platform molecules into hydrocarbon fuels with reduced oxygen content and improved H/C ratios. Liquid hydrocarbon fuels can be obtained by combining oxygen removal processes (e.g. dehydration, hydrogenation, hydrogenolysis, decarbonylation etc.) as well as by increasing the molecular weight via C-C coupling reactions (e.g. aldol condensation, ketonization, oligomerization, hydroxyalkylation etc.). Fundamentals and mechanistic aspects of the use of HDO catalysts in deoxygenation reactions will also be discussed. Copyright © 2014 Elsevier Ltd. All rights reserved.

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.

Investigation of polycyclic aromatic hydrocarbons (PAHs) and cyclic terpenoid biomarkers in the sediments of fishing harbors in Taiwan

International Nuclear Information System (INIS)

Kao, Nien-Hsin; Su, Ming-Chien; Fan, Jheng-Rong; Yen, Chih-Chun

2015-01-01

Highlights: • Biomarkers in three fishing harbors were investigated and identified. • 17 terpanes, 10 steranes and 10 bicyclic sesquiterpanes were quantified. • Marine diesel and the three kinds of lubricants were studied. • The study can be applied to other harbors to identify oil products in sediments. - Abstract: Three fishing harbors were investigated to study the polycyclic aromatic hydrocarbons in the sediments and trace possible anthropogenic sources by identification of cyclic terpenoid biomarkers. Seventeen terpanes, 10 steranes and 10 bicyclic sesquiterpanes in the marine diesel and the three kinds of lubricants that are mainly used by fishing boats were identified and quantified. Eighteen biomarker diagnostic ratios are suggested and the correlation coefficients among the lubricants and sediment samples have the R 2 value greater than 0.73. Analyzed 16 PAHs in the sediment shows non-normal distributions and the Kruskal Wallis Test shows the significant differences (p value smaller than 0.05) with the greatest variability in benzo[g,h,i]perylene which more than 84% of the effective size (E.S.) is accounted. X-ray Photoelectron Spectroscopy (XPS) analysis was applied and the Kruskal Wallis Test shows a significant difference (p value smaller than 0.05) among certain atoms with the effective size greater than 60%

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.

Aspects of petroleum hydrocarbon metabolism in marine animals

Science.gov (United States)

Mironov, O. G.

1980-03-01

Studies on hydrocarbon composition of Black Sea mussels Mytilus galloprovincialis sampled from different habitats indicate that the quantity and composition of hydrocarbons distributed in the molluscs depend on season and sea-water quality. The data obtained under experimental conditions testify to the possibility of hydrocarbon concentration in mussel tissues after death. During filtration in sea water containing oil and oil products, these pollutants are bound into faeces and pseudofaeces which contain a greater percentage of aromatic compounds than the oil initially present in sea water. Quantitative data are presented on hydrocarbon changes in mussel excretory products during transfer from oil-polluted to clean sea water. When Black Sea crabs Eriphia verrucosa are fed with mussels containing fuel-oil components accumulated from sea water, the pollutants concentrate in the whole body of the crab. This is in contrast to parenteral oil uptake, which leads to a concentration of most of the hydrocarbon in the muscles.

Total site integration of light hydrocarbons separation process

OpenAIRE

Ulyev, L.; Vasilyev, M.; Maatouk, A.; Duic, Neven; Khusanovc, Alisher

2016-01-01

Ukraine is the largest consumer of hydrocarbons per unit of production in Europe (Ukraine policy review, 2006). The most important point is a reduction of energy consumption in chemical and metallurgical industries as a biggest consumer. This paper deals with energy savings potential of light hydrocarbons separation process. Energy consumption of light hydrocarbons separation process processes typical of Eastern European countries were analysed. Process Integration (PI) was used to perform a ...

Study on surface geochemistry and microbiology for hydrocarbon exploration

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-12-01

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. The device is capable of determining hydrocarbon gases in water to the concentration of less than 5 x 10{sup -4} ml/l of water. According to the results of microbiological studies, the plate count technique can be a useful supplementary method for hydrocarbon exploration. This is based on the facts that the average survival rate to hydrocarbons (pentane, hexane) for heterotrophs is higher in the area known as containing considerable hydrocarbon gases than other areas in the Pohang region. However, it is still necessary to develop techniques to treat the bacteria with gaseous hydrocarbons. (author). 2 figs., 41 tabs.

Distribution and Source Apportionment of Polycyclic Aromatic Hydrocarbons (PAHs) in Forest Soils from Urban to Rural Areas in the Pearl River Delta of Southern China

Science.gov (United States)

Xiao, Yihua; Tong, Fuchun; Kuang, Yuanwen; Chen, Bufeng

2014-01-01

The upper layer of forest soils (0–20 cm depth) were collected from urban, suburban, and rural areas in the Pearl River Delta of Southern China to estimate the distribution and the possible sources of polycyclic aromatic hydrocarbons (PAHs). Total concentrations of PAHs in the forest soils decreased significantly along the urban–suburban–rural gradient, indicating the influence of anthropogenic emissions on the PAH distribution in forest soils. High and low molecular weight PAHs dominated in the urban and rural forest soils, respectively, implying the difference in emission sources between the areas. The values of PAH isomeric diagnostic ratios indicated that forest soil PAHs were mainly originated from traffic emissions, mixed sources and coal/wood combustion in the urban, suburban and rural areas, respectively. Principal component analysis revealed that traffic emissions, coal burning and residential biomass combustion were the three primary contributors to forest soil PAHs in the Pearl River Delta. Long range transportation of PAHs via atmosphere from urban area might also impact the PAHs distribution in the forest soils of rural area. PMID:24599040

Characterization of alkanes, hopanes, and polycyclic aromatic hydrocarbons (PAHs) in tar-balls collected from the East Coast of Peninsular Malaysia.

Science.gov (United States)

Chandru, Kuhan; Zakaria, Mohamad Pauzi; Anita, Sofia; Shahbazi, Azadeh; Sakari, Mahyar; Bahry, Pourya Shahpoury; Mohamed, Che Abd Rahim

2008-05-01

The East Coast of Peninsular Malaysia faces the South China Sea and is vulnerable to oil pollution because of intense petroleum production activities in the area. The South China Sea is also a favored route for supertankers carrying crude oil to the Far East. Consequently, oil spills can occur, causing pollution and contamination in the surrounding areas. Residual oil spills stranded on coastal beaches usually end up as tar-balls. Elucidating the sources of tar-balls using a molecular marker approach is essential in assessing environmental impacts and perhaps settling legal liabilities for affected parties. This study utilizes a multimodal molecular marker approach through the use of diagnostic ratios of alkanes, hopanes, and polycyclic aromatic hydrocarbons (PAHs) to determine the source, distribution and weathering of tar-balls. Hopane ratios (e.g., C29/C30, and summation C31-C35/C30 ratios) were used to identify the sources of tar-balls. The weathering effects were distinguished by using alkanes, namely the unresolved complex mixture (UCM) and low molecular weight/high molecular weight (L/H) ratios. Similarly, PAHs were also used for the determination of weathering processes undergone by the tar-balls. This multimodal molecular marker gave a very strong indication of the sources of tar-balls in this study. For example, 16 out of 17 samples originated from South East Asian Crude Oil (SEACO) with one sample from Merang, Terengganu originating from North Sea Oil (Troll). The TRME-2 sample may have come from a supertanker's ballast water discharge. The second possibility is that the tar-ball may have been transported via oceanographic currents. All 'weathered' sample characterizations were based on the presence of UCM and other ratios. The multimodal molecular marker approach applied in this study has enabled us to partially understand the transport behavior of tar-balls in the marine environment and has revealed insights into the weathering process of tar-balls.

Temperature-dependent mid-IR absorption spectra of gaseous hydrocarbons

International Nuclear Information System (INIS)

Klingbeil, Adam E.; Jeffries, Jay B.; Hanson, Ronald K.

2007-01-01

Quantitative mid-IR absorption spectra (2500-3400 cm -1 ) for 12 pure hydrocarbon compounds are measured at temperatures ranging from 25 to 500 deg. C using an FTIR spectrometer. The hydrocarbons studied are n-pentane, n-heptane, n-dodecane, 2,2,4-trimethyl-pentane (iso-octane), 2-methyl-butane, 2-methyl-pentane, 2,4,4-trimethyl-1-pentene, 2-methyl-2-butene, propene, toluene, m-xylene, and ethylbenzene. Room-temperature measurements of neat hydrocarbon vapor were made with an instrument resolution of both 0.1 and 1 cm -1 (FWHM) to confirm that the high-resolution setting was required only to resolve the propene absorption spectrum while the spectra of the other hydrocarbons could be resolved with 1 cm -1 resolution. High-resolution (0.1 cm -1 ), room-temperature measurements of neat hydrocarbons were made at low pressure (∼1 Torr, 133 Pa) and compared to measurements of hydrocarbon/N 2 mixtures at atmospheric pressure to verify that no pressure broadening could be observed over this pressure range. The temperature was varied between 25 and 500 o C for atmospheric-pressure measurements of hydrocarbon/N 2 mixtures (X hydrocarbon ∼0.06-1.5%) and it was found that the absorption cross section shows simple temperature-dependent behavior for a fixed wavelength over this temperature range. Comparisons with previous FTIR data over a limited temperature range and with high-resolution laser absorption data over a wide temperature range show good agreement

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.

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

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....

Characterization of non-methane hydrocarbons in Asian summer monsoon outflow observed by the CARIBIC aircraft

Directory of Open Access Journals (Sweden)

A. K. Baker

2011-01-01

Full Text Available Between April and December 2008 the CARIBIC commercial aircraft conducted monthly measurement flights between Frankfurt, Germany and Chennai, India. These flights covered the period of the Asian summer monsoon (June–September, during which enhancements in a number of atmospheric species were observed in the upper troposphere over southwestern Asia. In addition to in situ measurements of trace gases and aerosols, whole air samples were collected during the flights, and these were subsequently analyzed for a suite of trace gases that included a number of C₂–C₈ non-methane hydrocarbons. Non-methane hydrocarbons are relatively short-lived compounds and the large enhancements in their mixing ratios in the upper troposphere over southwestern Asia during the monsoon, sometimes more than double their spring and fall means, provides qualitative evidence for the influence of convectively uplifted boundary layer air. The particularly large enhancements of the combustion tracers benzene and ethyne, along with the similarity of their ratios with carbon monoxide and emission ratios from the burning of household biofuels, indicate a strong influence of biofuel burning to NMHC emissions in this region. Conversely, the ratios of ethane and propane to carbon monoxide, along with the ratio between i-butane and n-butane, indicate a significant source of these compounds from the use of fossil fuels, and comparison to previous campaigns suggests that this source could be increasing. Photochemical aging patterns of NMHCs showed that the CARIBIC samples were collected in two distinctly different regions of the monsoon circulation: a southern region where air masses had been recently influenced by low level contact and a northern region, where air parcels had spent substantial time in transit in the upper troposphere before being probed. Estimates of age using ratios of individual NMHCs have ranges of 3–6 days in the south and 9–12 days in

Process for the selective cracking of straight-chained and slightly branched hydrocarbons

Energy Technology Data Exchange (ETDEWEB)

Gorring, R L; Shipman, G F

1975-01-23

The invention describes a method for the selective (hydro) cracking of petroleum materials, containing normal straight-chained and/or slightly branched-chained hydrocarbons. The mixture is brought into contact with a selective, crystalline alumino silicate zeolite cracking catalyst housing a silicon oxide/aluminum oxide ratio of at least about 12 and a constraint index of about 1 to 12 under cracking conditions. A zeolite catalyst with a crystal size of up to 0.05 ..mu.. is used. Solidification point and viscosity in particular of oils are to be lowered through the catalytic dewaxing.

High-resolution record of pyrogenic polycyclic aromatic hydrocarbon deposition during the 20th century.

Science.gov (United States)

Lima, Ana Lúcia C; Eglinton, Timothy I; Reddy, Christopher M

2003-01-01

A high-resolution record of polycyclic aromatic hydrocarbon (PAH) deposition in Rhode Island over the past approximately 180 years was constructed using a sediment core from the anoxic Pettaquamscutt River basin. The record showed significantly more structure than has hitherto been reported and revealed four distinct maxima in PAH flux. The characteristic increase in PAH flux at the turn of the 20th century was captured in detail, leading to an initial maximum prior to the Great Depression. The overall peak in PAH flux in the 1950s was followed by a maximum that immediately preceded the 1973 Organization of Petroleum Exporting Countries (OPEC) oil embargo. During the most recent portion of the record, an abrupt increase in PAH flux between 1996 and 1999 has been found to follow a period of near constant fluxes. Because source-diagnostic ratios indicate that petrogenic inputs are minor throughout the record, these trends are interpreted in terms of past variations in the magnitude and type of combustion processes. For the most recent PAH maximum, energy consumption data suggest that diesel fuel combustion, and hence traffic of heavier vehicles, is the most probable cause for the increase in PAH flux. Systematic variations in the relative abundance of individual PAHs in conjunction with the above changes in flux are interpreted in relation to the evolution of combustion processes. Coronene, retene, and perylene are notable exceptions, exhibiting unique down-core profiles.

THE PENALIZED OPTIMAL EXPERIMENTAL DESIGN: THE PRECISE ESTIMATION OF AN INTERACTION THRESHOLD IN A MIXTURE OF EIGHTEEN POLYHALOGENATED AROMATIC HYDROCARBONS.

Science.gov (United States)

Crofton et al. (EHP, 2005) conducted a study of 18 polyhalogenated aromatic hydrocarbons (PHAHs) on serum total thyroxine (T4). Young female Long-Evans rats were dosed with the 18 single agents or a fixed-ratio mixture, and serum total T4 was measured via radioimmunoassay. The i...

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

Fate of PCBs, PAHs and their source characteristic ratios during composting and digestion of source-separated organic waste in full-scale plants

International Nuclear Information System (INIS)

Braendli, Rahel C.; Bucheli, Thomas D.; Kupper, Thomas; Mayer, Jochen; Stadelmann, Franz X.; Tarradellas, Joseph

2007-01-01

Composting and digestion are important waste management strategies. However, the resulting products can contain significant amounts of organic pollutants such as polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs). In this study we followed the concentration changes of PCBs and PAHs during composting and digestion on field-scale for the first time. Concentrations of low-chlorinated PCBs increased during composting (about 30%), whereas a slight decrease was observed for the higher chlorinated congeners (about 10%). Enantiomeric fractions of atropisomeric PCBs were essentially racemic and stable over time. Levels of low-molecular-weight PAHs declined during composting (50-90% reduction), whereas high-molecular-weight compounds were stable. The PCBs and PAHs concentrations did not seem to vary during digestion. Source apportionment by applying characteristic PAH ratios and molecular markers in input material did not give any clear results. Some of these parameters changed considerably during composting. Hence, their diagnostic potential for finished compost must be questioned. - During field-scale composting, low molecular weight PCBs and PAHs increased and decreased, respectively, whereas high molecular weight compounds remained stable

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)

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)

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

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.)

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.

Carbon Isotope Analyses of Individual Hydrocarbon Molecules in Bituminous Coal, Oil Shale and Murchison Meteorite

Directory of Open Access Journals (Sweden)

Kyoungsook Kim

1998-06-01

Full Text Available To study the origin of organic matter in meteorite, terrestrial rocks which contain organic compounds similar to the ones found in carbonaceous chondrites are studied and compared with Murchison meteorite. Hydrocarbon molecules were extracted by benzene and methanol from bituminous coal and oil shale and the extracts were partitioned into aliphatic, aromatic, and polar fractions by silica gel column chromatography. Carbon isotopic ratios in each fractions were analysed by GC-C-IRMS. Molecular compound identifications were carried by GC-MS Engine. Bituminous coal and oil shale show the organic compound composition similar to that of meteorite. Oil shale has a wide range of δ(13C, -20.1%_0 - -54.4%_0 compared to bituminous coal, -25.2%_0 - -34.3%_0. Delta values of several molecular compounds in two terrestrial samples are different. They show several distinct distributions in isotopic ratios compared to those of meteorite; Murchison meteorite has a range of δ(13C from -13%_0 to +30%_0. These results provide interpretation for the source and the formation condition of each rock, in particular alteration and migration processes of organic matter. Especially, they show an important clue whether some hydrocarbon molecules observed in meteorite are indigenous or not.

The differentiation of the character of solid lesions in the breast in the compression sonoelastography. Part II: Diagnostic value of BIRADS-US classification, Tsukuba score and FLR ratio

OpenAIRE

Dobruch-Sobczak, Katarzyna

2013-01-01

Sonoelastography is a dynamically developing method of ultrasound examination used to differentiate the character of focal lesions in the breasts. The aim of the Part II of the study is to determine the usefulness of sonoelastography in the differentiation diagnosis of focal breast lesions including the evaluation of the diagnostic value of Tsukuba score and FLR ratio in characterizing solid lesions in the breasts. Furthermore, the paper provides a comparison of classic B-mode imaging and son...

Hydrocarbon phytoremediation in the family Fabaceae--a review.

Science.gov (United States)

Hall, Jessica; Soole, Kathleen; Bentham, Richard

2011-04-01

Currently, studies often focus on the use of Poaceae species (grasses) for phytoremediation of hydrocarbon-contaminated soils. Research into the use of Fabaceae species (legumes) to remediate hydrocarbons in soils has been conducted, but these plants are commonly overlooked due to slower recorded rates of degradation compared with many grass species. Evidence in the literature suggests that in some cases Fabaceae species may increase total degradation of hydrocarbons and stimulate degradative capacity of the soil microbial community, particularly for contaminants which are normally more recalcitrant to degradation. As many recalcitrant hydrocarbons have negative impacts on human and ecosystem health, development of remediation options is crucial. Reconsideration of Fabaceae species for removal of such contaminants may lead to environmentally and economically sustainable technologies for remediation of contaminated sites.

The role of mass spectrometry in hydrocarbon analysis

International Nuclear Information System (INIS)

Kerenyi, E.

1980-01-01

Modern mass spectrometry has an outstandin.o role in solving problems concerning the composition and structure of hydrocarbon mixtures and their derivatives, petroleum and petrochemical products. Its efficiency in hydrocarbon analysis has been increased not only by high resolving power and computerized spectrum processing but also by the metastable ion spectrum technique promoting structural examinations, by mild ionization facilitating composition analysis, and by selective ion-detecting technique. The author presents the advantages of the metastable ion spectra, the field ionization, field desorption and other mild ionization methods, and finally, those of fragmentation analysis in connection with the examination of hydrocarbons and hydrocarbon derivatives. Examples taken from the literature and from the research work carried out in the Institute are also given. (author)

Enhancement of in situ Remediation of Hydrocarbon Contaminated Soil

Energy Technology Data Exchange (ETDEWEB)

Palmroth, M.

2006-07-01

Approximately 750 000 sites of contaminated land exist across Europe. The harmful chemicals found in Finnish soils include heavy metals, oil products, polyaromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), chlorophenols, and pesticides. Petroleum and petroleum products enter soil from ruptured oil pipelines, land disposal of refinery products, leaking storage tanks and through accidents. PAH contamination is caused by the spills of coal tar and creosote from coal gasification and wood treatment sites in addition to oil spills. Cleanup of soil by bioremediation is cheaper than by chemical and physical processes. However, the cleaning capacity of natural attenuation and in situ bioremediation is limited. The purpose of this thesis was to find feasible options to enhance in situ remediation of hydrocarbon contaminants. The aims were to increase the bioavailability of the contaminants and microbial activity at the subsurface in order to achieve higher contaminant removal efficiency than by intrinsic biodegradation alone. Enhancement of microbial activity and decrease of soil toxicity during remediation were estimated by using several biological assays. The performance of these assays was compared in order to find suitable indicators to follow the progress of remediation. Phytoremediation and chemical oxidation are promising in situ techniques to increase the degradation of hydrocarbons in soil. Phytoremediation is plant-enhanced decontamination of soil and water. Degradation of hydrocarbons is enhanced in the root zone by increased microbial activity and through the detoxifying enzymes of plants themselves. Chemical oxidation of contaminants by Fenton's reaction can produce degradation products which are more biodegradable than the parent compounds. Fenton's reaction and its modifications apply solutions of hydrogen peroxide and iron for the oxidation of organic chemicals. The cost of oxidation can be reduced by aiming at partial instead of full

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....

Bio-remediation of a sludge containing hydrocarbons

International Nuclear Information System (INIS)

Ayotamuno, M.J.; Okparanma, R.N.; Nweneka, E.K.; Ogaji, S.O.T.; Probert, S.D.

2007-01-01

Bio-augmentation has been used as a bio-remediation option for hydrocarbon-contaminated, oily-sludge restoration. This sludge was obtained from the Bonny-Terminal Improvement Project (BTIP) for Bonny Island, near Port Harcourt, Nigeria. Its total hydrocarbon-content (THC) was 69,372 mg/kg of sludge. Three treatment reactors (X, Y and Z) and one control reactor (A) were charged with 1500 g of oily sludge and 250 g of agricultural soil (i.e. an oily sludge to soil ratio of 6:1), the mixture homogenized and allowed to settle for seven days before various CFUs were added to reactors X, Y and Z. Reactor A did not receive any bio-preparation. The agricultural soil served both as a nutrient and a microbe carrier. With regularly scheduled mixing and watering, the THC reduction in the oily sludge varied between 40.7% and 53.2% within two weeks as well as between 63.7% and 84.5% within six weeks of applying the bio-remediation. The CFU counts of the added bio-preparation varied between 1.2 x 12 12 and 3.0 x 10 12 CFU/g of sludge and decreased to 7.0 x 10 11 CFU/g of sludge by the end of the sixth week. The pH of the degrading sludge fluctuated between 6.5 and 7.8 during the same period. When compared with the performance of the indigenous microbes in the control sample, the added bio-preparation evidently increased the THC reduction rate in the oily sludge

Structural segregation of petroleum and prospective hydrocarbon regions in Azerbaijan

International Nuclear Information System (INIS)

Kerimov, K.M.; Huseynov, A.N.; Hajiyev, F.M.

2002-01-01

Full text : Structural segregation allows identify the earth crust blocks according to their geological setting and structural history conductive for hydrocarbon generation and their entrapment in the sedimentary fill reservoirs. Since then there has been a need to design a new tectonic map of petroleum and hydrocarbons potential systems in Azerbaijan embracing both on- and offshore areas. Map's legend designed upon above mentioned concepts and principles has made it possible to evaluate the role of individual stratigraphic units in hydrocarbon generation and its entrapment, as well as in recognition of regional structural criteria of the hydrocarbon bearing potential of different structural patterns. Tectonic map of petroleum and prospective hydrocarbon bearing on and offshore areas in Azerbaijan for the first time contained a wide range of information related to structural criteria of hydrocarbon bearing potential, sedimentary fill's structural architecture, its thickness, both timing of their formation stages and basement consolidation, its subsidence depth, as well as hydrocarbon deposit areal and vertical distribution across individual regions. This map was considered to be of important implication both for the petroleum geoscience and petroleum industry endeavors.

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)

Process for making unsaturated hydrocarbons using microchannel process technology

Science.gov (United States)

Tonkovich, Anna Lee [Dublin, OH; Yuschak, Thomas [Lewis Center, OH; LaPlante, Timothy J [Columbus, OH; Rankin, Scott [Columbus, OH; Perry, Steven T [Galloway, OH; Fitzgerald, Sean Patrick [Columbus, OH; Simmons, Wayne W [Dublin, OH; Mazanec, Terry Daymo, Eric

2011-04-12

The disclosed invention relates to a process for converting a feed composition comprising one or more hydrocarbons to a product comprising one or more unsaturated hydrocarbons, the process comprising: flowing the feed composition and steam in contact with each other in a microchannel reactor at a temperature in the range from about 200.degree. C. to about 1200.degree. C. to convert the feed composition to the product, the process being characterized by the absence of catalyst for converting the one or more hydrocarbons to one or more unsaturated hydrocarbons. Hydrogen and/or oxygen may be combined with the feed composition and steam.

Identifying Malignant Pleural Effusion by A Cancer Ratio (Serum LDH: Pleural Fluid ADA Ratio).

Science.gov (United States)

Verma, Akash; Abisheganaden, John; Light, R W

2016-02-01

We studied the diagnostic potential of serum lactate dehydrogenase (LDH) in malignant pleural effusion. Retrospective analysis of patients hospitalized with exudative pleural effusion in 2013. Serum LDH and serum LDH: pleural fluid ADA ratio was significantly higher in cancer patients presenting with exudative pleural effusion. In multivariate logistic regression analysis, pleural fluid ADA was negatively correlated 0.62 (0.45-0.85, p = 0.003) with malignancy, whereas serum LDH 1.02 (1.0-1.03, p = 0.004) and serum LDH: pleural fluid ADA ratio 0.94 (0.99-1.0, p = 0.04) was correlated positively with malignant pleural effusion. For serum LDH: pleural fluid ADA ratio, a cut-off level of >20 showed sensitivity, specificity of 0.98 (95 % CI 0.92-0.99) and 0.94 (95 % CI 0.83-0.98), respectively. The positive likelihood ratio was 32.6 (95 % CI 10.7-99.6), while the negative likelihood ratio at this cut-off was 0.03 (95 % CI 0.01-0.15). Higher serum LDH and serum LDH: pleural fluid ADA ratio in patients presenting with exudative pleural effusion can distinguish between malignant and non-malignant effusion on the first day of hospitalization. The cut-off level for serum LDH: pleural fluid ADA ratio of >20 is highly predictive of malignancy in patients with exudative pleural effusion (whether lymphocytic or neutrophilic) with high sensitivity and specificity.

Urine microRNAs as biomarkers for bladder cancer: a diagnostic meta-analysis

Directory of Open Access Journals (Sweden)

Cheng Y

2015-08-01

Full Text Available Yidong Cheng,* Xiaheng Deng,* Xiao Yang,* Pengchao Li, Xiaolei Zhang, Peng Li, Jun Tao, Qiang Lu, Zengjun Wang Department of Urology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, People’s Republic of China *These authors contributed equally to this work Background: The diagnostic value of microRNA (miRNA detection in patients with bladder cancer (BCa is controversial. We performed a diagnostic meta-analysis to evaluate current evidence on the use of miRNA assays to diagnose BCa. Methods: We systematically searched PubMed, Embase, and Web of Science for studies published before March 31, 2015. The pooled sensitivity, specificity, positive and negative likelihood ratios, diagnostic odds ratio, and area under the curve (AUC were calculated to evaluate the overall test performance. Subgroup analyses were used to explore the between-study heterogeneity. Deeks’ funnel plot asymmetry test was used to test publication bias. We applied the software of RevMan 5.2 and Stata 11.0 to the meta-analysis. Results: A total of 23 studies from nine articles were included in the meta-analysis, with a total of 719 patients and 494 controls. The pooled sensitivity and specificity were 0.75 (95% confidence interval [CI], 0.68–0.80 and 0.75 (95% CI, 0.70–0.80, respectively. The pooled positive likelihood ratio was 3.03 (95% CI, 2.50–3.67; negative likelihood ratio was 0.33 (95% CI, 0.27–0.42; and diagnostic odds ratio was 9.07 (95% CI, 6.35–12.95. The pooled AUC was 0.81 (95% CI, 0.78–0.85. Subgroup analyses indicated that the multiple miRNAs assays and urine supernatant assays showed high accuracies in diagnosing BCa. Conclusion: The miRNA assays may serve as potential noninvasive diagnostic tool for the detection of BCa. However, the clinical application of miRNA assays for BCa diagnosis still needs further validation by large prospective studies. Keywords: microRNAs, bladder cancer, diagnostic accuracy, meta-analysis

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 ...

Optimization of a hydrocarbon bioremediation system at laboratory scale; Optimizacion de un sistema de biorremediacion de hidrocarburos a escala de laboratorio

Energy Technology Data Exchange (ETDEWEB)

Acuna, A. J.; Tonin, N. L.; Diaz, V.; Pucci, G. N.; Pucci, O. H. [Centro de Estudios e Investigacion en Microbiologia Aplicada (CEIMA), Universidad Nacional de la Patagonia San Juan Bosco (Argentina); ar, ntonin@unpata. edu.; com, victordj_2003@hotmail.; ar, granapu@unpata. edu.; ar, ceima@unpata. edu.

2012-01-15

The aim of this study was to optimize the parameters of moisture, temperature and ratio of nutrients to estimate the possibility of applying the technique of bioremediation in a soil contaminated with hydrocarbons. For this, an initial characterization of contaminated soil was made according to their physical and chemical characteristics and the number of heterotrophic and hydrocarbon degraders bacteria. Also the contaminant concentration by gravimetric method and by gas chromatography was studied. To optimize moisture and temperature, microcosms with moisture of 3%, 10%, 15% and 20% and temperatures of 5, 15, 28 and 37 degrees Celsius were used. The monitoring of the mineralization of hydrocarbons was performed by measuring the CO{sub 2} produced. To optimize the ratio of nutrients, different microcosms were designed and were monitored by oxygen consumption and by determination of hydrocarbons by gas chromatography. The C:N:P relationships studied were 100:20:2, 100:10:1, 100:5:0,5 and 100:1:0,1. The results indicate that the mineralization of hydrocarbons was optimal for moisture of 10% to 20% and temperatures of 25 degrees Celsius to 37 degrees Celsius with CO{sub 2} production values of 3000-4500 mg CO{sub 2} kg-1. The optimal C:N:P ratio was 100:1:0,1 in which the highest oxygen consumption was and the elimination of 83% of total hydrocarbons determined by gas chromatography with 78% and 89% of n-alkanes and polyaromatic hydrocarbons elimination, respectively. [Spanish] El objeto de este trabajo fue optimizar los parametros de humedad, temperatura y relacion de nutrientes para estimar la posibilidad de aplicar la tecnica de biorremediacion en un suelo contaminado con hidrocarburos. Para esto se realizo una caracterizacion inicial del suelo contaminado en funcion de sus caracteristicas fisicas y quimicas, su cantidad de microorganismos heterotrofos y degradadores de hidrocarburos. Tambien se estudio la concentracion del contaminante por metodo gravimetrico y

Evaluation of environmental samples containing heavy hydrocarbon components in environmental forensic investigations

Energy Technology Data Exchange (ETDEWEB)

Raia, J.C.; Blakley, C.R.; Fuex, A.N.; Villalanti, D.C.; Fahrenthold, P.D. [Triton Anal Corp, Houston, TX (United States)

2004-03-01

This article presents a procedure to evaluate and characterize environmental samples containing mixtures of hydrocarbons over a wide boiling range of materials that include fuels and other products used in commerce. The range of the method extends to the higher boiling and heavier molecular weight hydrocarbon products in the range of motor oil, bunker fuel, and heavier residue materials. The procedure uses the analytical laboratory technique of high-temperature simulated distillation along with mathematical regression of the analytical data to estimate the relative contribution of individual products in mixtures of hydrocarbons present in environmental samples. An analytical technique to determine hydrocarbon-type distributions by gas chromatography-mass spectrometry with nitric oxide ionization spectrometry evaluation is also presented. This type of analysis allows complex hydrocarbon mixtures to be classified by their chemical composition, or types of hydrocarbons that include paraffins, cycloparaffins, monoaromatics, and polycyclic aromatic hydrocarbons. Characteristic hydrocarbon patterns for example, in the relative distribution of polycyclic aromatic hydrocarbons are valuable for determining the potential origin of materials present in environmental samples. These methods provide quantitative data for hydrocarbon components in mixtures as a function of boiling range and 'hydrocarbon fingerprints' of the types of materials present. This information is valuable in assessing environmental impacts of hydrocarbons at contaminated sites and establishing the liabilities and cost allocations for responsible parties.

Combination of the ionic-to-atomic line intensity ratios from two test elements for the diagnostic of plasma temperature and electron number density in Inductively Coupled Plasma Atomic Emission Spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Tognoni, E. [Istituto per i Processi Chimico-Fisici, Area della Ricerca del Consiglio Nazionale delle Ricerche Via Moruzzi 1, 56124 Pisa (Italy)], E-mail: tognoni@ipcf.cnr.it; Hidalgo, M.; Canals, A. [Departamento de Quimica Analitica, Nutricion y Bromatologia. Universidad de Alicante. Apdo. 99, 03080, Alicante (Spain); Cristoforetti, G.; Legnaioli, S.; Salvetti, A.; Palleschi, V. [Istituto per i Processi Chimico-Fisici, Area della Ricerca del Consiglio Nazionale delle Ricerche Via Moruzzi 1, 56124 Pisa (Italy)

2007-05-15

In Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES) spectrochemical analysis, the MgII(280.270 nm)/MgI(285.213 nm) ionic to atomic line intensity ratio is commonly used as a monitor of the robustness of operating conditions. This approach is based on the univocal relationship existing between intensity ratio and plasma temperature, for a pure argon atmospheric ICP in thermodynamic equilibrium. In a multi-elemental plasma in the lower temperature range, the measurement of the intensity ratio may not be sufficient to characterize temperature and electron density. In such a range, the correct relationship between intensity ratio and plasma temperature can be calculated only when the complete plasma composition is known. We propose the combination of the line intensity ratios of two test elements (double ratio) as an effective diagnostic tool for a multi-elemental low temperature LTE plasma of unknown composition. In particular, the variation of the double ratio allows us discriminating changes in the plasma temperature from changes in the electron density. Thus, the effects on plasma excitation and ionization possibly caused by introduction of different samples and matrices in non-robust conditions can be more accurately interpreted. The method is illustrated by the measurement of plasma temperature and electron density in a specific analytic case.

Biofilm comprising phototrophic, diazotrophic, and hydrocarbon-utilizing bacteria: a promising consortium in the bioremediation of aquatic hydrocarbon pollutants.

Science.gov (United States)

Al-Bader, Dhia; Kansour, Mayada K; Rayan, Rehab; Radwan, Samir S

2013-05-01

Biofilms harboring simultaneously anoxygenic and oxygenic phototrophic bacteria, diazotrophic bacteria, and hydrocarbon-utilizing bacteria were established on glass slides suspended in pristine and oily seawater. Via denaturing gradient gel electrophoresis analysis on PCR-amplified rRNA gene sequence fragments from the extracted DNA from biofilms, followed by band amplification, biofilm composition was determined. The biofilms contained anoxygenic phototrophs belonging to alphaproteobacteria; pico- and filamentous cyanobacteria (oxygenic phototrophs); two species of the diazotroph Azospirillum; and two hydrocarbon-utilizing gammaproteobacterial genera, Cycloclasticus and Oleibacter. The coexistence of all these microbial taxa with different physiologies in the biofilm makes the whole community nutritionally self-sufficient and adequately aerated, a condition quite suitable for the microbial biodegradation of aquatic pollutant hydrocarbons.

Microbial consortia involved in the anaerobic degradation of hydrocarbons.

Science.gov (United States)

Zwolinski; Harris, R F; Hickey, W J

2000-01-01

In this review, we examine the energetics of well-characterized biodegradation pathways and explore the possibilities for these to support growth of multiple organisms interacting in consortia. The relevant phenotypic and/or phylogenetic characteristics of isolates and consortia mediating hydrocarbon degradation coupled with different terminal electron-accepting processes (TEAP) are also reviewed. While the information on metabolic pathways has been gained from the analysis of individual isolates, the energetic framework presented here demonstrates that microbial consortia could be readily postulated for hydrocarbon degradation coupled to any TEAP. Several specialized reactions occur within these pathways, and the organisms mediating these are likely to play a key role in defining the hydrocarbon degradation characteristics of the community under a given TEAP. Comparing these processes within and between TEAPs reveals biological unity in that divergent phylotypes display similar degradation mechanisms and biological diversity in that hydrocarbon-degraders closely related as phylotypes differ in the type and variety of hydrocarbon degradation pathways they possess. Analysis of microcosms and of field samples suggests that we have only begun to reveal the diversity of organisms mediating anaerobic hydrocarbon degradation. Advancements in the understanding of how hydrocarbon-degrading communities function will be significantly affected by the extent to which organisms mediating specialized reactions can be identified, and tools developed to allow their study in situ.

Clinical evaluation of free to total prostate specific antigen ratio in serum

International Nuclear Information System (INIS)

Cheng Wei; Deng Shouzhen; Lin Xiangtong

1999-01-01

Free and total prostate specific antigen (F-PSA and T-PSA) in serum were measured with immunoradiometric assay and the F/T-PSA ratio was calculated in 175 patients with T-PSA levels in the range of 4-20 μg/L. Among them 141 patients were benign prostatic hyperplasia (BPH), 23 were untreated prostate cancer (Pca untreated) and 11 were treated prostate cancer (Pca treated). The results showed that difference in F-PSA and F/T-PSA ratio for BPH group and Pca untreated group were statistically significant (P<0.01). The effectiveness of F/T-PSA ratio for Pca (89.9%) was higher than F-PSA (54.8%). The receiver-operating characteristic (ROC) curve showed an improved diagnostic efficacy of F/T-PSA ratio compared with T-PSA for discrimination between BPH and Pca. If mean F/T-PSA ratio value + 1 SE (13.2%) was used in BPH group as discrimination limits of Pca patients, the diagnostic accuracy of BPH group and Pca untreated group were 90.8% and 82.6% respectively. Thereby F/T-PSA ratio may be useful for the differentiation between BPH and prostate cancer

Impact of H2/CO ratios on phase and performance of Mn-modified Fe-based Fischer Tropsch synthesis catalyst

International Nuclear Information System (INIS)

Ding, Mingyue; Yang, Yong; Li, Yongwang; Wang, Tiejun; Ma, Longlong; Wu, Chuangzhi

2013-01-01

Highlights: ► Decreasing H 2 /CO ratio facilitated the conversion of Fe 3 O 4 to iron carbides on the surface layers. ► The formation of surface carbonaceous species was promoted in higher CO partial pressure. ► The formation of iron carbides on the surface of Fe 3 O 4 provided the FTS active sites. ► Decreasing H 2 /CO ratio promoted the product shifting towards heavy hydrocarbons. - Abstract: Impacts of H 2 /CO ratios on both the bulky and surface compositions of an iron–manganese based catalyst were investigated by XRD, MES, N 2 -physisorption, XPS and LRS. Fischer–Tropsch (F–T) synthesis performances were studied in a slurry-phase continuously stirred tank reactor. The characterization results showed that the fresh catalyst was comprised of the hematite, which was converted firstly to Fe 3 O 4 , and then carburized to iron carbides in both the bulk and surface regions under different H 2 /CO ratios atmosphere. Pretreatment in lower H 2 /CO ratio facilitated the formation of iron carbides on the surface of magnetite and surface carbonaceous species. During the F–T synthesis reaction, the catalyst reduced in lower H 2 /CO ratio presented higher catalytic activity, which is assigned probably to the formation of more iron carbides (especially for χ-Fe 5 C 2 ) on the surface of magnetite. The increase of CO partial pressure promoted the product distribution shifting towards heavy hydrocarbons

Global climate change due to the hydrocarbon industry

International Nuclear Information System (INIS)

Almasi, M.; Racz, L.

1999-01-01

An overview is presented on the industry's response to the agreements of the Rio de Janeiro (1992) and Kyoto (1987) conventions on climate change, and to other international agreements. The announcements by large petroleum companies on the changes introduced according to the international commitments in order to fight climatic impacts of hydrocarbon fuels. The problems and foreseeable future of the Hungarian hydrocarbon industry with environmental protection are discussed. Finally, emission abatement and control possibilities of hydrocarbon combustion are considered. (R.P.)

Nature of hydrocarbon activation in oxidative ammonolysis of propane to acrylonitrile over a gallium-antimony oxide catalyst

Energy Technology Data Exchange (ETDEWEB)

Osipova, Z.G.; Sokolovskii, V.D.

1979-03-01

The nature of hydrocarbon activation in oxidative ammonolysis of propane to acrylonitrile over a gallium-antimony oxide catalyst GaSbNiPOx (1:3:1.5:1 atomic ratios of the elements) was studied by comparing the rate of this reaction at 550/sup 0/C and 5Vertical Bar3< by vol propane/6Vertical Bar3< ammonia/18.6Vertical Bar3< oxygen/70.4Vertical Bar3< helium reactant mixture with that of isobutane ammoxidation to methacrylonitrile under the same conditions, at low (Vertical Bar3; 20Vertical Bar3<) conversions that prevent secondary oxidation of the products. Both the over-all hydrocarbon conversion rate and that of nitrile formation were higher for propane, suggesting that the reactions proceed via the respective carbanions (probably primary carbanions), rather than carbocations or uncharged radicals.

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.)

Effects of blend ratio between high density polyethylene and biomass on co-gasification behavior in a two-stage gasification system

KAUST Repository

Park, Jae Hyun; Park, Hyun-Woo; Choi, Sooseok; Park, Dong-Wha

2016-01-01

into syngas in a high temperature region of thermal plasma. At the equivalence ratio of 0.47, conversion selectivities of CO and H2 from hydrocarbons were calculated to be 74% and 44%, respectively. © 2016 Hydrogen Energy Publications LLC.

Distribution and geochemical application of aromatic hydrocarbons in crude oils

International Nuclear Information System (INIS)

Asif, M.; Tahira, F.

2007-01-01

Distribution of aromatic hydrocarbons was studied in a set of crude oils, five from northern Indus basin of potwar area and two from southern Indus basin. Diaromatic and triaromatic hydrocarbons were separated from highly complex mixture of sedimentary organic matter by using liquid chromatography techniques such as column chromatography, TLC and GC-FID. These classes of compounds were identified to alkylated isomers of naphthalenes and phenanthrenes by using reference chromatograms and literature data. High concentration of di-,tri- and tetra-methyl naphthalenes was observed in all crude oils except Kal. The relative increase in concentration of alkyl naphthalenes was found as moved to higher methyl substituted isomers. This suggests that they are the product of sedimentary alkylation reactions during catagensis and metagensis. The significant concentration of methyl phenanthrenes indicated source of organic matter. High levels of both 1-MP and 9-MP showed marine and terrestrial source of organic matter except Umer crude oil which is most likely to have terrestrial origin. The ratios of beta-substituted to the alpha-substituted isomers of both alkyl naphthalenes and alkyl phenanthrene were used to assess the thermal maturity of sedimentary organic matter, which revealed high maturity level of Dhurnal, Pindori, Badin and Toot crude oils. (author)

Novel Photocatalytic Reactor Development for Removal of Hydrocarbons from Water

Directory of Open Access Journals (Sweden)

Morgan Adams

2008-01-01

Full Text Available Hydrocarbons contamination of the marine environment generated by the offshore oil and gas industry is generated from a number of sources including oil contaminated drill cuttings and produced waters. The removal of hydrocarbons from both these sources is one of the most significant challenges facing this sector as it moves towards zero emissions. The application of a number of techniques which have been used to successfully destroy hydrocarbons in produced water and waste water effluents has previously been reported. This paper reports the application of semiconductor photocatalysis as a final polishing step for the removal of hydrocarbons from two waste effluent sources. Two reactor concepts were considered: a simple flat plate immobilised film unit, and a new rotating drum photocatalytic reactor. Both units proved to be effective in removing residual hydrocarbons from the effluent with the drum reactor reducing the hydrocarbon content by 90% under 10 minutes.

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

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.

Evaluation of mineral oil saturated hydrocarbons (MOSH and mineral oil aromatic hydrocarbons (MOAH in pure mineral hydrocarbon-based cosmetics and cosmetic raw materials using 1H NMR spectroscopy [version 2; referees: 3 approved

Directory of Open Access Journals (Sweden)

Dirk W. Lachenmeier

2017-08-01

Full Text Available Mineral hydrocarbons consist of two fractions, mineral oil saturated hydrocarbons (MOSH and mineral oil aromatic hydrocarbons (MOAH. MOAH is a potential public health hazard because it may include carcinogenic polycyclic compounds. In the present study, 400 MHz nuclear magnetic resonance (NMR spectroscopy was introduced, in the context of official controls, to measure MOSH and MOAH in raw materials or pure mineral hydrocarbon final products (cosmetics and medicinal products. Quantitative determination (qNMR has been established using the ERETIC methodology (electronic reference to access in vivo concentrations based on the PULCON principle (pulse length based concentration determination. Various mineral hydrocarbons (e.g., white oils, paraffins or petroleum jelly were dissolved in deuterated chloroform. The ERETIC factor was established using a quantification reference sample containing ethylbenzene and tetrachloronitrobenzene. The following spectral regions were integrated: MOSH δ 3.0 – 0.2 ppm and MOAH δ 9.2 - 6.5, excluding solvent signals. Validation showed a sufficient precision of the method with a coefficient of variation <6% and a limit of detection <0.1 g/100 g. The applicability of the method was proven by analysing 27 authentic samples with MOSH and MOAH contents in the range of 90-109 g/100 g and 0.02-1.10 g/100 g, respectively. It is important to distinguish this new NMR-approach from the hyphenated liquid chromatography-gas chromatography methodology previously used to characterize MOSH/MOAH amounts in cosmetic products. For mineral hydrocarbon raw materials or pure mineral hydrocarbon-based cosmetic products, NMR delivers higher specificity without any sample preparation besides dilution. Our sample survey shows that previous methods may have overestimated the MOAH amount in mineral oil products and opens new paths to characterize this fraction. Therefore, the developed method can be applied for routine monitoring of consumer

Forensic fingerprinting and source identification of the 2009 Sarnia (Ontario) oil spill.

Science.gov (United States)

Wang, Zhendi; Yang, C; Yang, Z; Sun, J; Hollebone, B; Brown, C; Landriault, M

2011-11-01

This paper presents a case study in which integrated forensic oil fingerprinting and data interpretation techniques were used to characterize the chemical compositions and determine the source of the 2009 Sarnia (Ontario) oil spill incident. The diagnostic fingerprinting techniques include determination of hydrocarbon groups and semi-quantitative product-type screening via gas chromatography (GC), analysis of oil-characteristic biomarkers and the extended suite of parent and alkylated PAH (polycyclic aromatic hydrocarbon) homologous series via gas chromatography-mass spectrometry (GC-MS), determination and comparison of a variety of diagnostic ratios of "source-specific marker" compounds, and determination of the weathering degree of the spilled oil, and whether the spilled oil hydrocarbons have been mixed with any other "background" chemicals (biogenic and/or pyrogenic hydrocarbons). The detailed chemical fingerprinting data and results reveal the following: (1) all four samples are mixtures of diesel and lubricating oil with varying percentages of diesel to lube oil. Both samples 1460 and 1462 are majority diesel-range oil mixed with a smaller portion of lube oil. Sample 1461 contains slightly less diesel-range oil. Sample 1463 is majority lubricating-range oil. (2) The diesel in the four diesel/lube oil mixture samples was most likely the same diesel and from the same source. (3) The spill sample 1460 and the suspected-source sample 1462 have nearly identical concentrations and distribution patterns of target analytes including TPHs, n-alkane, PAHs and biomarker compounds; and have nearly identical diagnostic ratios of target compounds as well. Furthermore, a perfect "positive match" correlation line (with all normalized ratio data points falling into the straight correlation line) is clearly demonstrated. It is concluded that the spill oil water sample 1460 (#1, from the water around the vessel enclosed by a boom) matches with the suspected source sample 1462

MAST magnetic diagnostics

Science.gov (United States)

Edlington, T.; Martin, R.; Pinfold, T.

2001-01-01

The mega-ampere spherical tokamak (MAST) experiment is a new, large, low aspect ratio device (R=0.7-0.8 m, a=0.5-0.65 m, maximum BT˜0.63 T at R=0.7 m) operating its first experimental physics campaign. Designed to study a wide variety of plasma shapes with up to 2 MA of plasma current with an aspect ratio down to 1.3, the poloidal field (PF) coils used for plasma formation, equilibrium and shaping are inside the main vacuum vessel. For plasma control and to investigate a wide range of plasma phenomena, an extensive set of magnetic diagnostics have been installed inside the vacuum vessel. More than 600 vacuum compatible, bakeable diagnostic coils are configured in a number of discrete arrays close to the plasma edge with about half the coils installed behind the graphite armour tiles covering the center column. The coil arrays measure the toroidal and poloidal variation in the equilibrium field and its high frequency fluctuating components. Internal coils also measure currents in the PF coils, plasma current, stored energy and induced currents in the mechanical support structures of the coils and graphite armour tiles. The latter measurements are particularly important when halo currents are induced following a plasma termination, for example, when the plasma becomes vertically unstable. The article describes the MAST magnetic diagnostic coil set and their calibration. The way in which coil signals are used to control the plasma equilibrium is described and data from the first MAST experimental campaign presented. These coil data are used as input to the code EFIT [L. Lao et al., Nucl. Fusion 25, 1611 (1985)], for measurement of halo currents in the vacuum vessel structure and for measurements of the structure of magnetic field fluctuations near the plasma edge.

Diagnostic Accuracy of Global Pharma Health Fund Minilab™ in Assessing Pharmacopoeial Quality of Antimicrobials.

Science.gov (United States)

Pan, Hui; Ba-Thein, William

2018-01-01

Global Pharma Health Fund (GPHF) Minilab™, a semi-quantitative thin-layer chromatography (TLC)-based commercially available test kit, is widely used in drug quality surveillance globally, but its diagnostic accuracy is unclear. We investigated the diagnostic accuracy of Minilab system for antimicrobials, using high-performance liquid chromatography (HPLC) as reference standard. Following the Minilab protocols and the Pharmacopoeia of the People's Republic of China protocols, Minilab-TLC and HPLC were used to test five common antimicrobials (506 batches) for relative concentration of active pharmaceutical ingredients. The prevalence of poor-quality antimicrobials determined, respectively, by Minilab TLC and HPLC was amoxicillin (0% versus 14.9%), azithromycin (0% versus 17.4%), cefuroxime axetil (14.3% versus 0%), levofloxacin (0% versus 3.0%), and metronidazole (0% versus 38.0%). The Minilab TLC had false-positive and false-negative detection rates of 2.6% (13/506) and 15.2% (77/506) accordingly, resulting in the following test characteristics: sensitivity 0%, specificity 97.0%, positive predictive value 0, negative predictive value 0.8, positive likelihood ratio 0, negative likelihood ratio 1.0, diagnostic odds ratio 0, and adjusted diagnostic odds ratio 0.2. This study demonstrates unsatisfying diagnostic accuracy of Minilab system in screening poor-quality antimicrobials of common use. Using Minilab as a stand-alone system for monitoring drug quality should be reconsidered.

Analysis of hydrocarbons generated in coalbeds

Science.gov (United States)

Butala, Steven John M.

This dissertation describes kinetic calculations using literature data to predict formation rates and product yields of oil and gas at typical low-temperature conditions in coalbeds. These data indicate that gas formation rates from hydrocarbon thermolysis are too low to have generated commercial quantities of natural gas, assuming bulk first-order kinetics. Acid-mineral-catalyzed cracking, transition-metal-catalyzed hydrogenolysis of liquid hydrocarbons, and catalyzed CO2 hydrogenation form gas at high rates. The gaseous product compositions for these reactions are nearly the same as those for typical natural coalbed gases, while those from thermal and catalytic cracking are more representative of atypical coalbed gases. Three Argonne Premium Coals (Upper-Freeport, Pittsburgh #8 and Lewiston-Stockton) were extracted with benzene in both Soxhlet and elevated pressure extraction (EPE) systems. The extracts were compared on the basis of dry mass yield and hydrocarbon profiles obtained by gas chromatography/mass spectrometry. The dry mass yields for the Upper-Freeport coal gave consistent results by both methods, while the yields from the Pittsburgh #8 and Lewiston-Stockton coals were greater by the EPE method. EPE required ˜90 vol. % less solvent compared to Soxhlet extraction. Single-ion-chromatograms of the Soxhlet extracts all exhibited bimodal distributions, while those of the EPE extracts did not. Hydrocarbons analyzed from Greater Green River Basin samples indicate that the natural oils in the basin originated from the coal seams. Analysis of artificially produced oil indicates that hydrous pyrolysis mimics generation of C15+ n-alkanes, but significant variations were found in the branched alkane, low-molecular-weight n-alkanes, and high-molecular-weight aromatic hydrocarbon distributions.

Characteristics of polycyclic aromatic hydrocarbons in PM2.5 emitted from different cooking activities in China.

Science.gov (United States)

Li, Yun-Chun; Qiu, Jia-Qian; Shu, Man; Ho, Steven Sai Hang; Cao, Jun-Ji; Wang, Ge-Hui; Wang, Xian-Xiang; Zhao, Xiao-Qing

2018-02-01

Nineteen polycyclic aromatic hydrocarbons (PAHs) in PM 2.5 emitted from five different cooking activities were characterized, and their influencing factors were determined. The total quantified particle-bounded PAH concentrations (ΣPAHs) in the airs from the cooking activities were 4.2-36.5-fold higher than those in corresponding backgrounds. The highest ΣPAHs were seen in cafeteria frying (783 ± 499 ng/m 3 ), followed by meat roasting (420 ± 191 ng/m 3 ), fish roasting (210 ± 105 ng/m 3 ), snack-street boiling (202 ± 230 ng/m 3 ), and cafeteria boiling (150 ± 65 ng/m 3 ). The main influencing factors on the PAH emissions were cooking methods, fat contents in raw materials, and oil consumptions. Four- to six-ringed PAHs had the highest contributions to the ΣPAHs (avg. 87.5%). Diagnostic ratios of individual PAH were similar between the two charbroiling and other three conventional Chinese cooking methods, respectively, demonstrating the dominance of cooking methods in the PAH emissions. Remarkably high benzo(b)fluoranthene/benzo(k)fluoranthene (BbF/BkF) ratio (8.31) was seen in the snack-street boiling, attributed to the coal combustion as cooking fuel. Both fluoranthene/(fluoranthene + pyrene) [FLT/(FLT + PYR)] and benzo(a)anthracene/(benzo(a)anthracene + chrysene) [BaA/(BaA + CHR)] ratios were higher for the oil-based cooking than those from the water-based ones. In addition, two ratios of indeno(1,2,3-cd)pyrene/(indeno(1,2,3-cd)pyrene + benzo(g,h,i)perylene) [IPY/(IPY + BPE)] and benzo(a)pyrene/(benzo(a)pyrene + benzo(g,h,i)perylene) [BaP/(BaP + BPE)] were higher for two charbroiling than the three conventional Chinese cooking methods. The characterization work in this study is particularly important since cooking is a potential contributor of atmospheric PAHs in urban China. Carcinogenic potencies of PAHs were assessed by comparison with the air quality guideline and health risk estimation. The BaP and BaP equivalent were

Cuticle hydrocarbons in saline aquatic beetles

Directory of Open Access Journals (Sweden)

María Botella-Cruz

2017-07-01

Full Text Available Hydrocarbons are the principal component of insect cuticle and play an important role in maintaining water balance. Cuticular impermeability could be an adaptative response to salinity and desiccation in aquatic insects; however, cuticular hydrocarbons have been poorly explored in this group and there are no previous data on saline species. We characterized cuticular hydrocarbons of adults and larvae of two saline aquatic beetles, namely Nebrioporus baeticus (Dytiscidae and Enochrus jesusarribasi (Hydrophilidae, using a gas chromatograph coupled to a mass spectrometer. The CHC profile of adults of both species, characterized by a high abundance of branched alkanes and low of unsaturated alkenes, seems to be more similar to that of some terrestrial beetles (e.g., desert Tenebrionidae compared with other aquatic Coleoptera (freshwater Dytiscidae. Adults of E. jesusarribasi had longer chain compounds than N. baeticus, in agreement with their higher resistance to salinity and desiccation. The more permeable cuticle of larvae was characterized by a lower diversity in compounds, shorter carbon chain length and a higher proportion of unsaturated hydrocarbons compared with that of the adults. These results suggest that osmotic stress on aquatic insects could exert a selection pressure on CHC profile similar to aridity in terrestrial species.

Task 8: Evaluation of hydrocarbon potential

International Nuclear Information System (INIS)

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

1994-01-01

Our studies focus on the stratigraphy of Late Devonian to early Pennsylvanian rocks at the NTS, because these are the best potential hydrocarbon source rocks in the vicinity of Yucca Mountain. In the last year, our stratigraphic studies have broadened to include the regional context for both the Chainman and the Eleana formations. New age data based on biostratigraphy constrain the age ranges of both Chainman and Eleana; accurate and reliable ages are essential for regional correlation and for regional paleogeographic reconstructions. Source rock analyses throughout the Chainman establish whether these rocks contained adequate organic material to generate hydrocarbons. Maturation analyses of samples from the Chainman determine whether the temperature history has been suitable for the generation of liquid hydrocarbons. Structural studies are aimed at defining the deformation histories and present position of the different packages of Devonian - Pennsylvanian rocks. This report summarizes new results of our structural, stratigraphic and hydrocarbon source rock potential studies at the Nevada Test Site and vicinity. Stratigraphy is considered first, with the Chainman Shale and Eleana Formation discussed separately. New biostratigraphic results are included in this section. New results from our structural studies are summarized next, followed by source rock and maturation analyses of the Chainman Shale. Directions for future work are included where appropriate

Characterization of light gaseous hydrocarbons of the surface soils of Krishna-Godavari basin, India.

Science.gov (United States)

Lakshmi, M; Rasheed, M A; Madhavi, T; Kalpana, M S; Patil, D J; Dayal, A M

2012-01-01

Several techniques are used for the exploration of hydrocarbons, of which; the geochemical techniques involving the microbiological technique use the principle of detecting the light hydrocarbon seepage activities for indication of sub-surface petroleum accumulations. Asurvey was carried out to characterize the light gaseous hydrocarbons seeping in oil and gas fields of Krishna-Godavari basin ofAndhra Pradesh. Aset of 50 sub-soil samples were collected at depths of about 3 m for geochemical analyses and 1m for microbiological analysis. The microbial prospecting studies showed the presence of high bacterial population for methane 2.5 x 10(2) to 6.0 x 10(6) cfu g(-1), propane 1x10(2) to 8.0 x 10(6) cfu g(-1) in soil samples. The adsorbed soil gas analysis showed the presence of moderate to low concentrations of methane (26 to 139 ppb), ethane (0 to 17 ppb), propane (0 to 8 ppb), butane (0 to 5 ppb) and pentane (0 to 2 ppb) in the soil samples of the study area. Carbon isotope analysis for methane ('13C1) ranging from -36.6 to -22.7 per hundred Pee Dee Belemnite (PDB) suggests these gases are of thermogenic origin. Geo-microbial prospecting method coupled with adsorbed soil gas and carbon isotope ratio analysis have thus shown good correlation with existing oil/gas fields of Krishna-Godavari basin.

Nonmethane hydrocarbons in the rural southeast United States national parks

Science.gov (United States)

Kang, Daiwen; Aneja, Viney P.; Zika, Rod G.; Farmer, Charles; Ray, John D.

2001-02-01

Measurements of volatile organic compounds (VOCs) were made at three rural sites in the southeast U.S. national parks: Mammoth Cave National Park, Kentucky; Cove Mountain, Great Smoky Mountains National Park, Tennessee; and Big Meadows, Shenandoah National Park, Virginia. In 1995 the three locations were sampling sites for the Southern Oxidants Study (SOS) Nashville Intensive, and the measurements of VOCs for Shenandoah were also made under contract with the National Park Service. Starting in 1996, the National Park Service added the other two parks to the monitoring contract. Hydrocarbon measurements made during June through September for the years 1995, 1996, and 1997 were analyzed in this study. Source classification techniques based on correlation coefficient, chemical reactivity, and ratioing were developed and applied to these data. The results show that anthropogenic VOCs from automobile exhaust appeared to be dominant at Mammoth Cave National Park, and at Cove Mountain, Great Smoky Mountains National Park, but other sources were also important at Big Meadows, Shenandoah National Park. Correlation and ratio analysis based on chemical reactivity provides a basis for source-receptor relationship. The most abundant ambient VOCs varied both in concentration and order depending on park and year, but the following VOCs appeared on the top 10 list for all three sites: isoprene (6.3 to 18.4 ppbv), propane (2.1 to 12.9 ppbv), isopentane (1.3 to 5.7 ppbv), and toluene (1.0 to 7.2 ppbv). Isoprene is naturally emitted by vegetation, and the others are produced mainly by fossil fuel combustion and industrial processes. Propylene-equivalent concentrations were calculated to account for differences in reaction rates between the hydroxyl radical and individual hydrocarbons, and to thereby estimate their relative contributions to ozone formation.

Contamination levels, toxicity profiles, and emission sources of polycyclic aromatic hydrocarbons (PAHs) in the soils of an emerging industrial town and its environs in the Southeastern Nigeria.

Science.gov (United States)

Ofomatah, Anthony C; Okoye, Chukwuma O B

2017-11-09

Polycyclic aromatic hydrocarbon (PAH) concentrations in Nnewi and its environs were determined. Soil samples were extracted by sonication using hexane:dichloromethane (3:1) mixture and determined by gas chromatography-flame ionization detection. The total PAHs concentrations (μg/kg) were 16.681 to 46.815, being three orders of magnitude lower than the maximum permissible level recommended by the Agency for Toxic Substances and Disease Registry (ATSDR). These concentrations followed this order: industrial ˃ farmlands ˃ commercial ˃ residential. Industrialized areas showed higher concentrations (p ˂ 0.05) than the other areas. Diagnostic ratios show that the major source of PAHs was the open burning of industrial and agricultural wastes, as shown by the occurrence of highest concentrations in the industrial areas, followed by agricultural areas. Benzo[a]pyrene equivalent values showed non-pollution and very low toxicity. Nevertheless, it was clear that industrialization has had some impact on the PAHs levels in soils and the total environment in this area and could be problematic with time, except with proper environmental management.

Hydrocarbon Reserves: Abundance or Scarcity

Energy Technology Data Exchange (ETDEWEB)

NONE

2005-07-01

IFP and the OAPEC jointly organize a regular international seminar dealing with world oil-related problems appearing in the news. For the first time, this seminar has been opened to oil and gas company specialists, service companies, research centers and independents. This year's theme concerns oil and gas reserves: are they abundant or are we headed towards the shortages announced by some experts? This theme is especially topical in that: oil and gas currently meet two thirds of world energy needs and almost completely dominate the transport sector; the reserves declared by the OAPEC countries account for nearly half of world reserves; the price of a barrel of oil went through the roof in 2004; world energy demand is growing fast and alternative sources of energy are far from ready to take over from oil and gas in the next few decades. Since the reserves correspond to the volume it is technically and economically viable to produce, the seminar has, of course, dealt with the technical and economic questions that arise in connection with exploration and production, but it has also considered changes in the geopolitical context. Presentations by the leading companies of the OAPEC countries and by the IFP group were completed by presentation from the International Energy Agency (IEA), the United States Geological Survey (USGS), the IHS Energy Group, Total and Gaz de France. This document gathers the transparencies of the following presentations: Hydrocarbon reserves in OAPEC members countries: current and future (M. Al-Lababidi); Non OAPEC liquid reserves and production forecasts (Y. Mathieu); World oil and gas resources and production outlook (K. Chew); Global investments in the upstream (F. Birol); Total's policy in the oil and gas sector (C. de Margerie); Gaz de France's policy in the oil and gas sector (J. Abiteboul); NOC/IOC's opportunities in OPEC countries (I. Sandrea); Relationships between companies, countries and investors: How they may impact on the growth

Hydrocarbon Reserves: Abundance or Scarcity

International Nuclear Information System (INIS)

2005-01-01

IFP and the OAPEC jointly organize a regular international seminar dealing with world oil-related problems appearing in the news. For the first time, this seminar has been opened to oil and gas company specialists, service companies, research centers and independents. This year's theme concerns oil and gas reserves: are they abundant or are we headed towards the shortages announced by some experts? This theme is especially topical in that: oil and gas currently meet two thirds of world energy needs and almost completely dominate the transport sector; the reserves declared by the OAPEC countries account for nearly half of world reserves; the price of a barrel of oil went through the roof in 2004; world energy demand is growing fast and alternative sources of energy are far from ready to take over from oil and gas in the next few decades. Since the reserves correspond to the volume it is technically and economically viable to produce, the seminar has, of course, dealt with the technical and economic questions that arise in connection with exploration and production, but it has also considered changes in the geopolitical context. Presentations by the leading companies of the OAPEC countries and by the IFP group were completed by presentation from the International Energy Agency (IEA), the United States Geological Survey (USGS), the IHS Energy Group, Total and Gaz de France. This document gathers the transparencies of the following presentations: Hydrocarbon reserves in OAPEC members countries: current and future (M. Al-Lababidi); Non OAPEC liquid reserves and production forecasts (Y. Mathieu); World oil and gas resources and production outlook (K. Chew); Global investments in the upstream (F. Birol); Total's policy in the oil and gas sector (C. de Margerie); Gaz de France's policy in the oil and gas sector (J. Abiteboul); NOC/IOC's opportunities in OPEC countries (I. Sandrea); Relationships between companies, countries and investors: How they may impact on the growth

A new diagnostic approach for bilious pleural effusion.

Science.gov (United States)

Saraya, Takeshi; Light, Richard W; Sakuma, Sho; Nakamoto, Yasuo; Wada, Shoko; Ishida, Manabu; Inui, Toshiya; Koide, Takashi; Ishii, Haruyuki; Takizawa, Hajime

2016-09-01

Bilious pleural effusion is an extremely rare condition associated with liver diseases, subphrenic or subhepatic abscess formation, biliary peritonitis, and invasive procedures (i.e., percutaneous biliary drainage or liver biopsy). The current diagnostic test is based on the measurement of the ratio of pleural total bilirubin to serum total bilirubin, which is greater than 1 in patients with bilious pleural effusion. Given the low incidence of bilious pleural effusion, the precise diagnostic yield of this ratio based test has not been evaluated. We retrospectively reviewed the medical records of our institution and searched the PubMed database for reports of bilious pleural effusion. We identified a total of 12 cases of bilious pleural effusion (9 from 8 Pubmed reports and 3 from our institutional records). The factors causing this condition were broadly classified into three categories based on the pathophysiology: 1) liver diseases (echinococcosis, tuberculosis and amebiasis); 2) subhepatic/subphrenic abscess or biliary peritonitis, with or without biliary tract obstruction; and 3) iatrogenic disease after percutaneous biliary drainage and/or liver biopsy. The sensitivity of detection was 76.9% when the ratio of pleural total bilirubin to serum total bilirubin was greater than 1. The sensitivity increased to 100% when a combination test including pleural glycoholic acid was adopted. This study demonstrates the high diagnostic yield for bilious pleural effusion using a combination of two test criteria; a ratio of pleural total bilirubin to serum total bilirubin greater than 1 and the presence of pleural glycoholic acid. Copyright © 2016 The Japanese Respiratory Society. Published by Elsevier B.V. All rights reserved.

Magneto-electroluminescence effects in the single-layer organic light-emitting devices with macrocyclic aromatic hydrocarbons

Directory of Open Access Journals (Sweden)

S.-T. Pham

2018-02-01

Full Text Available Magneto-electroluminescence (MEL effects are observed in single-layer organic light-emitting devices (OLEDs comprising only macrocyclic aromatic hydrocarbons (MAHs. The fluorescence devices were prepared using synthesized MAHs, namely, [n]cyclo-meta-phenylene ([n]CMP, n = 5, 6. The MEL ratio of the resulting OLED is 1%–2% in the spectral wavelength range of 400-500 nm, whereas it becomes negative (−1.5% to −2% in the range from 650 to 700 nm. The possible physical origins of the sign change in the MEL are discussed. This wavelength-dependent sign change in the MEL ratio could be a unique function for future single-layer OLEDs capable of magnetic-field-induced color changes.

Magneto-electroluminescence effects in the single-layer organic light-emitting devices with macrocyclic aromatic hydrocarbons

Science.gov (United States)

Pham, S.-T.; Ikemoto, K.; Suzuki, K. Z.; Izumi, T.; Taka, H.; Kita, H.; Sato, S.; Isobe, H.; Mizukami, S.

2018-02-01

Magneto-electroluminescence (MEL) effects are observed in single-layer organic light-emitting devices (OLEDs) comprising only macrocyclic aromatic hydrocarbons (MAHs). The fluorescence devices were prepared using synthesized MAHs, namely, [n]cyclo-meta-phenylene ([n]CMP, n = 5, 6). The MEL ratio of the resulting OLED is 1%-2% in the spectral wavelength range of 400-500 nm, whereas it becomes negative (-1.5% to -2%) in the range from 650 to 700 nm. The possible physical origins of the sign change in the MEL are discussed. This wavelength-dependent sign change in the MEL ratio could be a unique function for future single-layer OLEDs capable of magnetic-field-induced color changes.

Light hydrocarbon emissions from African savanna burnings

International Nuclear Information System (INIS)

Bonsang, B.; Lambert, G.; Boissard, C.C.

1991-01-01

A study was undertaken in West Africa to determine the background mixing ratio of nonmethane hydrocarbons (NMHC) during the dry season and to measure the composition of savanna burnings. The experiment was conducted from 13 to 22 January 1989 in the experimental station located at the border of the tropical rainforest and savanna. Samples were collected during aircraft flights at 2,400 m in the free troposphere, at 400 m in the haze layer and in a smoke plume at 200 m altitude. Samples representing the ground-level evolution of the local background were collected at 10 m altitude. Fire samples were collected at a short distance from the fires during the intensive experiments. Results are presented in tables and indicate that the effect of NMHC produced by biomass burning on the tropospheric photochemistry is limited to a few species, namely, C 2 -C 4 alkenes

High atmosphere–ocean exchange of semivolatile aromatic hydrocarbons

KAUST Repository

González-Gaya, Belén

2016-05-16

Polycyclic aromatic hydrocarbons, and other semivolatile aromatic-like compounds, are an important and ubiquitous fraction of organic matter in the environment. The occurrence of semivolatile aromatic hydrocarbons is due to anthropogenic sources such as incomplete combustion of fossil fuels or oil spills, and other biogenic sources. However, their global transport, fate and relevance for the carbon cycle have been poorly assessed, especially in terms of fluxes. Here we report a global assessment of the occurrence and atmosphere-ocean fluxes of 64 polycyclic aromatic hydrocarbons analysed in paired atmospheric and seawater samples from the tropical and subtropical Atlantic, Pacific and Indian oceans. The global atmospheric input of polycyclic aromatic hydrocarbons to the global ocean is estimated at 0.09 Tg per month, four times greater than the input from the Deepwater Horizon spill. Moreover, the environmental concentrations of total semivolatile aromatic-like compounds were 10 2 -10 3 times higher than those of the targeted polycyclic aromatic hydrocarbons, with a relevant contribution of an aromatic unresolved complex mixture. These concentrations drive a large global deposition of carbon, estimated at 400 Tg C yr -1, around 15% of the oceanic CO2 uptake. © 2016 Macmillan Publishers Limited.

Bioremediation in soil contaminated with hydrocarbons in Colombia.

Directory of Open Access Journals (Sweden)

María Alejandra Trujillo Toro

2012-10-01

Full Text Available This study analyzes bioremediation processes of hydrocarbon contaminated soils in Colombia as a sustainable alternative to the deterioration of environmental quality by hydrocarbon spillage. According to national and international environmental law, all waste contaminated with hydrocarbons is considered dangerous waste, and therefore it cannot be released in the ground, water or be incinerated. Such legislation has motivated companies around the world to implement treatment processes for contaminated soils. Within Colombia, oil companies have been implementing the bioremediation of hydrocarbon contaminated soils in order to manage the waste coming from activities of oil drilling, refinement, transport and distribution.These practices must be considered viable for their ease of implementation, their low overhead costs, and for the benefits they provide towards environmental quality. Among the positive impacts that these practices have generated, it may consider the following: a solution for the problem of hydrocarbon contaminated soils, alternatives for the ultimate disposal of said waste without affecting ground, water or air resources, the low cost of the operation, and the technical experience of sustainable development which can continue to be implemented in companies dealing with dangerous waste.

Do Cuticular Hydrocarbons Provide Sufficient Information for Optimal Sex Allocation in the Ant Formica exsecta?

DEFF Research Database (Denmark)

van Zweden, Jelle Stijn; Vitikainen, Emma; D'Ettorre, Patrizia

2011-01-01

Split sex ratio theory predicts that when kin structure varies among colonies of social insects, in order to maximize the inclusive fitness, colonies with relatively high sister-sister relatedness should specialize in producing reproductive females, whereas in those with relatively low sister......-sister relatedness workers should bias their sex ratio towards males. However, in order to achieve this, workers need to be able to reliably assess the type of colony in which they live. The information on colony kin structure may be encoded in cuticular hydrocarbons (CHCs), assuming that genetic variability....... However, within-colony relatedness remains the key determinant of colony sex ratios. Based on our results, CHC variability cannot serve as accurate information on within-colony relatedness, kin structure, or full-sib affiliation, nor do workers seem to use colony CHC variability as a proxy for sex...

Diagnostic value of WIF1 methylation for colorectal cancer: a meta-analysis

Science.gov (United States)

Chen, Min; Huang, Tianyi; Chen, Yuehong; Ji, Huihui; Pan, Ranran; Wang, Tiangong; Jiang, Danjie; Chen, Yanfei; Yang, Yong; Duan, Shiwei

2018-01-01

As a common antagonist of Wnt/β-catenin signaling, Wnt inhibitory factor 1 (WIF1) plays an important role in the tumor progression. The aim of our meta-analysis was to summarize the diagnostic value of WIF1 methylation in colorectal cancer (CRC). Eligible studies were retrieved by a systemic search among PubMed, Embase, CNKI, and Wanfang literature databases. The diagnostic value of WIF1 methylation for CRC was assessed by the summary receiver operating characteristics (SROC) test. Our meta-analysis of 12 studies between 1420 CRC samples and 946 control samples showed that WIF1 hypermethylation was significantly associated with CRC (P < 0.001, OR = 30.10, 95% CI = 19.48-46.50). WIF1 hypermethylation, as a diagnostic biomarker for CRC, has a pooled sensitivity of 0.40 (95% CI: 0.37-0.42), a pooled specificity of 0.95 (95% CI: 0.93-0.96), a pooled positive-likelihood ratio (PLR) of 8.65 (95% CI, 4.47-16.73), and a pooled negative-likelihood ratio (NLR) of 0.41 (95% CI, 0.30-0.55), a diagnostic odds ratio (DOR) of 26.86 (95% CI: 15.73-45.89), and an area under the curve (AUC) of 0.9115. In conclusion, our study established that WIF1 hypermethylation might be a promising diagnostic biomarker for CRC. PMID:29435185

Compositional changes of aromatic steroid hydrocarbons in naturally weathered oil residues in the Egyptian western desert

International Nuclear Information System (INIS)

Barakat, A.O.; Qian, Y.; Kim, M.; Kennicutt, M.C. II

2002-01-01

Aromatic steranes are geochemical markers that can be used to study the maturation of organic matter of sediments and to correlate crude oils and source rocks. In this study, naturally weathered oil residues from an arid waste disposal site in Al-Alamein, Egypt, were analyzed for monoaromatic and triaromatic steranes to show the usefulness of biomarker compounds in assessing changes in chemical composition during the degradation of oil residues that have been released onto terrestrial environments. Gas chromatography and mass spectrometry were used to characterize the individual aromatic compounds. Results indicate that triaromatic sterane distributions are similar in oil residues with varying extents of weathering. The distribution correlated with a fresh crude oil sample from Western Desert-sourced oil. Molecular ratios of triaromatic sterane compounds were found to be suitable for source identification. The major changes in chemical compositions resulting from the weathering of the oil included the depletion of short chain mono- and tri-aromatic steranes in extremely weathered samples. The results of the triaromatic sterane distribution correspond with weathering classifications based on the analyses of saturated and aromatic hydrocarbons and the ratios of n-alkanes, polycyclic aromatic hydrocarbons, and saturate biomarker compounds. 15 refs., 3 tabs., 3 figs

Mechanics of vacuum-enhanced recovery of hydrocarbons

International Nuclear Information System (INIS)

Barnes, D.L.; McWhorter, D.B.

1995-01-01

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

Antioxidant Functions of the Aryl Hydrocarbon Receptor

Directory of Open Access Journals (Sweden)

Cornelia Dietrich

2016-01-01

Full Text Available The aryl hydrocarbon receptor (AhR is a transcription factor belonging to the basic helix-loop-helix/PER-ARNT-SIM family. It is activated by a variety of ligands, such as environmental contaminants like polycyclic aromatic hydrocarbons or dioxins, but also by naturally occurring compounds and endogenous ligands. Binding of the ligand leads to dimerization of the AhR with aryl hydrocarbon receptor nuclear translocator (ARNT and transcriptional activation of several xenobiotic phase I and phase II metabolizing enzymes. It is generally accepted that the toxic responses of polycyclic aromatic hydrocarbons, dioxins, and structurally related compounds are mediated by activation of the AhR. A multitude of studies indicate that the AhR operates beyond xenobiotic metabolism and exerts pleiotropic functions. Increasing evidence points to a protective role of the AhR against carcinogenesis and oxidative stress. Herein, I will highlight data demonstrating a causal role of the AhR in the antioxidant response and present novel findings on potential AhR-mediated antioxidative mechanisms.

Spectroscopic diagnostics of NIF ICF implosions using line ratios of Kr dopant in the ignition capsule

Science.gov (United States)

Dasgupta, Arati; Ouart, Nicholas; Giuiani, John; Clark, Robert; Schneider, Marilyn; Scott, Howard; Chen, Hui; Ma, Tammy

2017-10-01

X ray spectroscopy is used on the NIF to diagnose the plasma conditions in the ignition target in indirect drive ICF implosions. A platform is being developed at NIF where small traces of krypton are used as a dopant to the fuel gas for spectroscopic diagnostics using krypton line emissions. The fraction of krypton dopant was varied in the experiments and was selected so as not to perturb the implosion. Our goal is to use X-ray spectroscopy of dopant line ratios produced by the hot core that can provide a precise measurement of electron temperature. Simulations of the krypton spectra using a 1 in 104 atomic fraction of krypton in direct-drive exploding pusher with a range of electron temperatures and densities show discrepancies when different atomic models are used. We use our non-LTE atomic model with a detailed fine-structure level atomic structure and collisional-radiative rates to investigate the krypton spectra at the same conditions. Synthetic spectra are generated with a detailed multi-frequency radiation transport scheme from the emission regions of interest to analyze the experimental data with 0.02% Kr concentration and compare and contrast with the existing simulations at LLNL. Work supported by DOE/NNSA; Part of this work was also done under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract No. DE-AC52-07NA27344.

Spot protein-creatinine ratio and spot albumin-creatinine ratio in the assessment of pre-eclampsia: a diagnostic accuracy study with decision-analytic model-based economic evaluation and acceptability analysis.

Science.gov (United States)

Waugh, Jason; Hooper, Richard; Lamb, Edmund; Robson, Stephen; Shennan, Andrew; Milne, Fiona; Price, Christopher; Thangaratinam, Shakila; Berdunov, Vladislav; Bingham, Jenn

2017-10-01

The National Institute for Health and Care Excellence (NICE) guidelines highlighted the need for 'large, high-quality prospective studies comparing the various methods of measuring proteinuria in women with new-onset hypertensive disorders during pregnancy'. The primary objective was to evaluate quantitative assessments of spot protein-creatinine ratio (SPCR) and spot albumin-creatinine ratio (SACR) in predicting severe pre-eclampsia (PE) compared with 24-hour urine protein measurement. The secondary objectives were to investigate interlaboratory assay variation, to evaluate SPCR and SACR thresholds in predicting adverse maternal and fetal outcomes and to assess the cost-effectiveness of these models. This was a prospective diagnostic accuracy cohort study, with decision-analytic modelling and a cost-effectiveness analysis. The setting was 36 obstetric units in England, UK. Pregnant women (aged ≥ 16 years), who were at > 20 weeks' gestation with confirmed gestational hypertension and trace or more proteinuria on an automated dipstick urinalysis. Women provided a spot urine sample for protein analysis (the recruitment sample) and were asked to collect a 24-hour urine sample, which was stored for secondary analysis. A further spot sample of urine was taken immediately before delivery. Outcome data were collected from hospital records. There were four index tests on a spot sample of urine: (1) SPCR test (conducted at the local laboratory); (2) SPCR test [conducted at the central laboratory using the benzethonium chloride (BZC) assay]; (3) SPCR test [conducted at the central laboratory using the pyrogallol red (PGR) assay]; and (4) SACR test (conducted at the central laboratory using an automated chemistry analyser). The comparator tests on 24-hour urine collection were a central test using the BZC assay and a central test using the PGR assay. The primary reference standard was the NICE definition of severe PE. Secondary reference standards were a clinician

Determination of the hydrocarbon-degrading metabolic capabilities of tropical bacterial isolates

Energy Technology Data Exchange (ETDEWEB)

Marquez-Rocha, F.J.; Olmos-Soto, J. [Centro de Investigacion Cientifica y de Educacion Superior de Ensenada, San Diego, CA (United States). Departamento de Biotecnologia Marina; Rosano-Hernandez, M.A.; Muriel-Garcia, M. [Instituto Mexicano del Petroleo, CD Carmen Camp (Mexico). Zona Marina/Tecnologia Ambiental

2005-01-01

Of more than 20 bacteria isolated from a tropical soil using minimal medium supplemented with hydrocarbons, 11 grew well on diesel as sole carbon source, and another 11 grew in the presence of polynuclear aromatic hydrocarbons (PAHs). Ten isolates were identified phenotypically as Pseudomonas sp. and eight as Bacillus sp. Gene sequences representing the catabolic genes (alkM, todM, ndoM, and xylM) and 16S rRNA gene sequences characteristic for Pseudomona and Bacillus were amplified by PCR, using DNA recovered from the supernatant of hydrocarbon-contaminated soil suspensions. Based on their rapid growth characteristics in the presence of hydrocarbons and the formation of PCR products for the catabolic genes alkM and ndoM six isolates were selected for biodegradation assays. After 30 days a mixed culture of two isolates achieved close to 70% hydrocarbon removal and apparent mineralization of 16% of the hydrocarbons present in the soil. Biodegradation rates varied from 275 to 387 mg hydrocarbon kg{sup -1} day{sup -1}. Several bacterial isolates obtained in this study have catabolic capabilities for the biodegradation of alkanes and aromatic hydrocarbons including PAHs. (author)

Alkanes as Components of Soil Hydrocarbon Status: Behavior and Indication Significance

Science.gov (United States)

Gennadiev, A. N.; Zavgorodnyaya, Yu. A.; Pikovskii, Yu. I.; Smirnova, M. A.

2018-01-01

Studies of soils on three key plots with different climatic conditions and technogenic impacts in Volgograd, Moscow, and Arkhangelsk oblasts have showed that alkanes in the soil exchange complex have some indication potential for the identification of soil processes. The following combinations of soil-forming factors and processes have been studied: (a) self-purification of soil after oil pollution; (b) accumulation of hydrocarbons coming from the atmosphere to soils of different land use patterns; and (c) changes in the soil hydrocarbon complex beyond the zone of technogenic impact due to the input of free hydrocarbon-containing gases. At the injection input of hydrocarbon pollutants, changes in the composition and proportions of alkanes allow tracing the degradation trend of pollutants in the soil from their initial content to the final stage of soil self-purification, when the background concentrations of hydrocarbons are reached. Upon atmospheric deposition of hydrocarbons onto the soil, from the composition and mass distribution of alkanes, conclusions can be drawn about the effect of toxicants on biogeochemical processes in the soil, including their manifestation under different land uses. Composition analysis of soil alkanes in natural landscapes can reveal signs of hydrocarbon emanation fluxes in soils. The indication potentials of alkanes in combination with polycyclic aromatic hydrocarbons and other components of soil hydrocarbon complex can also be used for the solution of other soil-geochemical problems.

Transient Elastography vs. Aspartate Aminotransferase to Platelet Ratio Index in Hepatitis C: A Meta-Analysis.

Science.gov (United States)

Mattos, A Z; Mattos, A A

Many different non-invasive methods have been studied with the purpose of staging liver fibrosis. The objective of this study was verifying if transient elastography is superior to aspartate aminotransferase to platelet ratio index for staging fibrosis in patients with chronic hepatitis C. A systematic review with meta-analysis of studies which evaluated both non-invasive tests and used biopsy as the reference standard was performed. A random-effects model was used, anticipating heterogeneity among studies. Diagnostic odds ratio was the main effect measure, and summary receiver operating characteristic curves were created. A sensitivity analysis was planned, in which the meta-analysis would be repeated excluding each study at a time. Eight studies were included in the meta-analysis. Regarding the prediction of significant fibrosis, transient elastography and aspartate aminotransferase to platelet ratio index had diagnostic odds ratios of 11.70 (95% confidence interval = 7.13-19.21) and 8.56 (95% confidence interval = 4.90-14.94) respectively. Concerning the prediction of cirrhosis, transient elastography and aspartate aminotransferase to platelet ratio index had diagnostic odds ratios of 66.49 (95% confidence interval = 23.71-186.48) and 7.47 (95% confidence interval = 4.88-11.43) respectively. In conclusion, there was no evidence of significant superiority of transient elastography over aspartate aminotransferase to platelet ratio index regarding the prediction of significant fibrosis, but the former proved to be better than the latter concerning prediction of cirrhosis.

Cuticular hydrocarbons for species determination of tropical termites

Science.gov (United States)

Michael I. Haverty; Lori J. Nelson; Barbara L. Thorne; Margaret S. Collins; Johanna P.E.C. Darlington; Marion Page

1992-01-01

Cuticular hydrocarbons can be used to discriminate species in Coptotermes and Nasutitermes, here discussed for selected species from locations in the Pacific Rim and several Caribbean islands. We recently reexamined the cuticular hydrocarbons of Coptotermes formosanus and identified several dimethylalkanes that...

Graph theory for alternating hydrocarbons with attached ports

NARCIS (Netherlands)

Hesselink, Wim H.

Properties of molecules of certain hydrocarbons give rise to difficult questions in graph theory. This paper is primarily devoted to the graph theory, but the physico-chemical motivation, which is somewhat speculative, is also presented. Molecules of unsaturated hydrocarbons exhibit alternating

Advanced Diagnostics for High Pressure Spray Combustion.

Energy Technology Data Exchange (ETDEWEB)

Skeen, Scott A.; Manin, Julien Luc; Pickett, Lyle M.

2014-06-01

The development of accurate predictive engine simulations requires experimental data to both inform and validate the models, but very limited information is presently available about the chemical structure of high pressure spray flames under engine- relevant conditions. Probing such flames for chemical information using non- intrusive optical methods or intrusive sampling techniques, however, is challenging because of the physical and optical harshness of the environment. This work details two new diagnostics that have been developed and deployed to obtain quantitative species concentrations and soot volume fractions from a high-pressure combusting spray. A high-speed, high-pressure sampling system was developed to extract gaseous species (including soot precursor species) from within the flame for offline analysis by time-of-flight mass spectrometry. A high-speed multi-wavelength optical extinction diagnostic was also developed to quantify transient and quasi-steady soot processes. High-pressure sampling and offline characterization of gas-phase species formed following the pre-burn event was accomplished as well as characterization of gas-phase species present in the lift-off region of a high-pressure n-dodecane spray flame. For the initial samples discussed in this work several species were identified, including polycyclic aromatic hydrocarbons (PAH); however, quantitative mole fractions were not determined. Nevertheless, the diagnostic developed here does have this capability. Quantitative, time-resolved measurements of soot extinction were also accomplished and the novel use of multiple incident wavelengths proved valuable toward characterizing changes in soot optical properties within different regions of the spray flame.

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.

Method and apparatus for preventing agglomeration within fluid hydrocarbons

International Nuclear Information System (INIS)

Woodbridge, D.D.

1979-01-01

This invention relates to a process for treating a fluid hydrocarbon fuel for retarding the agglomeration between particles thereof and for retarding the growth of bacteria and fungi therein. The process includes that steps of transporting a plurality of unit volumes of said fluid hydrocarbon fuel through an irradiating location and irradiating each unit of the plurality of unit volumes at the irradiating location with either neutron or gamma radiation. An apparatus for treating the fluid hydrocarbon fuels with the nuclear radiation also is provided. The apparatus includes a generally conical central irradiating cavity which is surrounded by a spiral outer irradiating cavity. The fluid hydrocarbon fuel is transported through the cavities while being irradiated by the nuclear radiation

Methods for natural gas and heavy hydrocarbon co-conversion

Science.gov (United States)

Kong, Peter C [Idaho Falls, ID; Nelson, Lee O [Idaho Falls, ID; Detering, Brent A [Idaho Falls, ID

2009-02-24

A reactor for reactive co-conversion of heavy hydrocarbons and hydrocarbon gases and includes a dielectric barrier discharge plasma cell having a pair of electrodes separated by a dielectric material and passageway therebetween. An inlet is provided for feeding heavy hydrocarbons and other reactive materials to the passageway of the discharge plasma cell, and an outlet is provided for discharging reaction products from the reactor. A packed bed catalyst may optionally be used in the reactor to increase efficiency of conversion. The reactor can be modified to allow use of a variety of light sources for providing ultraviolet light within the discharge plasma cell. Methods for upgrading heavy hydrocarbons are also disclosed.

Method of removing deterioration product in hydrocarbon type solvent

International Nuclear Information System (INIS)

Ito, Yoshifumi; Takashina, Toru; Murasawa, Kenji.

1988-01-01

Purpose: To remarkably reduce radioactive wastes by bringing adsorbents comprising titanium oxide and/or zirconium oxide into contact with hydrocarbon type solvents. Method: In a nuclear fuel re-processing step, an appropriate processing is applied to extraction solvents suffering from radioactive degradation, to separate the hydrocarbon solvents and store them in a solvent tank. Then, titanium oxide and/or zirconium oxide adsorbents are continuously mixed and agitated therewith to adsorb degradation products on the adsorbents. Then, they are introduced with adsorbent separators to recover purified hydrocarbon type solvents. Meanwhile, the separated adsorbents are discharged from pipeways. This enables to regenerate the hydrocarbon type solvents for reuse, as well as remarkably reduce the radioactive wastes. (Takahashi, M.)

Diagnostic accuracy of dual-energy computed tomography in patients with gout: A meta-analysis.

Science.gov (United States)

Lee, Young Ho; Song, Gwan Gyu

2017-08-01

This study aimed to evaluate the diagnostic performance of dual-energy computed tomography (DECT) for patients with gout. We searched the Medline, Embase, and Cochrane Library databases, and performed a meta-analysis on the diagnostic accuracy of DECT in patients with gout. A total of eight studies including 510 patients with gout and 268 controls (patients with non-gout inflammatory arthritis) were available for the meta-analysis. The pooled sensitivity and specificity of DECT were 84.7% (95% confidence interval [CI]: 81.3-87.7) and 93.7% (93.0-96.3), respectively. The positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio were 9.882 (6.122-15.95), 0.163 (0.097-0.272), and 78.10 (31.14-195.84), respectively. The area under the curve of DECT was 0.956 and the Q * index was 0.889, indicating a high diagnostic accuracy. Some between-study heterogeneity was found in the meta-analyses. However, there was no evidence of a threshold effect (Spearman correlation coefficient = 0.419; p = 0.035). In addition, meta-regression showed that the sample size, study design, and diagnostic criteria were not sources of heterogeneity, and subgroup meta-analyses did not change the overall diagnostic accuracy. Our meta-analysis of published studies demonstrates that DECT has a high diagnostic accuracy and plays an important role in the diagnosis of gout. Copyright © 2017 Elsevier Inc. All rights reserved.

Risk analysis associated with petroleum hydrocarbons: is everything running smoothly?

International Nuclear Information System (INIS)

Morin, D.

1999-01-01

Petroleum products represent one of the main sources of environmental contamination, and these products are complex, composed of several hundred individual hydrocarbons. The evaluation of the risks associated with petroleum products is often limited by certain specific parameters such as benzene. The petroleum hydrocarbons running from C(10) to C(50) are not often integrated in an analysis of the toxological risks since the toxological characterization of a complex mixture of hydrocarbons is difficult to carry out. There exist in the United States two approaches that were developed recently that allow the integration of various hydrocarbons comprising a mixture. In this presentation, two of these approaches are described and compared. An overview of these approaches related to Canadian regulatory bodies is included, and a case study completes the account. The two approaches that are most well known in this area are: 1) that of the Massachusetts Dept. of Environmental Protection, and 2) that of the Total Petroleum Hydrocarbon Criteria Working Group. The integration of petroleum hydrocarbons in a quantitative evaluation of their toxological risk is possible by present methods. This integration allows a reduction in the uncertainty associated with the use of an integrating parameter in the case of these petroleum hydrocarbons in the C(10) to the C(50) range

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

Studies on hydrocarbon degradation by the bacterial isolate ...

African Journals Online (AJOL)

The hydrocarbon utilizing capability of Stenotrophomonas rhizophila (PM-1), isolated from oil contaminated soil composts from Western Ghats region of Karnataka was analyzed. In the bioremediation experiment, ONGC heavy crude oil and poly aromatic hydrocarbons (PAHs) utilization by the bacterial isolate was studied.

DETECTIONS OF WATER ICE, HYDROCARBONS, AND 3.3 μm PAH IN z ∼ 2 ULIRGs

International Nuclear Information System (INIS)

Sajina, Anna; Spoon, Henrik; Yan Lin; Imanishi, Masatoshi; Fadda, Dario; Elitzur, Moshe

2009-01-01

We present the first detections of the 3 μm water ice and 3.4 μm amorphous hydrocarbon (HAC) absorption features in z ∼ 2 ULIRGs. These are based on deep rest-frame 2-8 μm Spitzer Infrared Spectrograph spectra of 11 sources selected for their appreciable silicate absorption. The HAC-to-silicate ratio for our z ∼ 2 sources is typically higher by a factor of 2-5 than that observed in the Milky Way. This HAC 'excess' suggests compact nuclei with steep temperature gradients as opposed to predominantly host obscuration. Beside the above molecular absorption features, we detect the 3.3 μm polycyclic aromatic hydrocarbon (PAH) emission feature in one of our sources with three more individual spectra showing evidence for it. Stacking analysis suggests that water ice, hydrocarbons, and PAH are likely present in the bulk of this sample even when not individually detected. The most unexpected result of our study is the lack of clear detections of the 4.67 μm CO gas absorption feature. Only three of the sources show tentative signs of this feature at significantly lower levels than has been observed in local ULIRGs. Overall we find that the closest local analogs to our sources, in terms of 3-4 μm color, HAC-to-silicate and ice-to-silicate ratios, as well as low PAH equivalent widths, are sources dominated by deeply obscured nuclei. Such sources form only a small fraction of ULIRGs locally and are commonly believed to be dominated by buried active galactic nuclei (AGNs). Our sample suggests that, in an absolute number, such buried AGNs are at least an order of magnitude more common at z ∼ 2 than today. The presence of PAH suggests that significant levels of star formation are present even if the obscured AGNs typically dominate the power budget.

Hydrocarbon studies in Puget Sound and off the Washington coast. Progress report, March 1978--February 1979

International Nuclear Information System (INIS)

Carpenter, R.; Fairhall, A.W.

1979-01-01

This report summarizes the past year's progress in our studies of the amounts, types, and probable origins of aliphatic, aromatic, S-, and N-containing hydrocarbons in sediments, organisms, and waters of Puget Sound and the Washington coast. We are trying to identify the relative importance of the various possible sources of these substances, the major pathways by which they are transferred through some parts of the marine food web, their rates of transfer, and their ultimate fates. We have found that changes in aliphatic and aromatic hydrocarbon compositions are evident in 210 Pb-dated sediment cores from central Puget Sound. These changes are due both to natural diagenetic processes and to low-level inputs of fossil fuels from a variety of sources. We have found measurable amounts of both S- and N-containing compounds in these Puget Sound sediments. Our studies of the role of zooplankton fecal pellets in the cycling of trace chemicals in the sea have shown that fecal pellets are an important vertical transport agent for hydrocarbons in the sea. We now have defined the natural variations in 14 C and 13 C/ 12 C isotope ratios of the inorganic carbon in Puget Sound seawater. Carbon isotope abundances for organisms and sediments are also reported for selected sites

Mechanical reliability analysis of tubes intended for hydrocarbons

Energy Technology Data Exchange (ETDEWEB)

Nahal, Mourad; Khelif, Rabia [Badji Mokhtar University, Annaba (Algeria)

2013-02-15

Reliability analysis constitutes an essential phase in any study concerning reliability. Many industrialists evaluate and improve the reliability of their products during the development cycle - from design to startup (design, manufacture, and exploitation) - to develop their knowledge on cost/reliability ratio and to control sources of failure. In this study, we obtain results for hardness, tensile, and hydrostatic tests carried out on steel tubes for transporting hydrocarbons followed by statistical analysis. Results obtained allow us to conduct a reliability study based on resistance request. Thus, index of reliability is calculated and the importance of the variables related to the tube is presented. Reliability-based assessment of residual stress effects is applied to underground pipelines under a roadway, with and without active corrosion. Residual stress has been found to greatly increase probability of failure, especially in the early stages of pipe lifetime.

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.

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

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

Process to separate alkali metal salts from alkali metal reacted hydrocarbons

Energy Technology Data Exchange (ETDEWEB)

Gordon, John Howard; Alvare, Javier; Larsen, Dennis; Killpack, Jeff

2017-06-27

A process to facilitate gravimetric separation of alkali metal salts, such as alkali metal sulfides and polysulfides, from alkali metal reacted hydrocarbons. The disclosed process is part of a method of upgrading a hydrocarbon feedstock by removing heteroatoms and/or one or more heavy metals from the hydrocarbon feedstock composition. This method reacts the oil feedstock with an alkali metal and an upgradant hydrocarbon. The alkali metal reacts with a portion of the heteroatoms and/or one or more heavy metals to form an inorganic phase containing alkali metal salts and reduced heavy metals, and an upgraded hydrocarbon feedstock. The inorganic phase may be gravimetrically separated from the upgraded hydrocarbon feedstock after mixing at a temperature between about 350.degree. C. to 400.degree. C. for a time period between about 15 minutes and 2 hours.

Process for scavenging hydrogen sulfide from hydrocarbon gases

International Nuclear Information System (INIS)