981 resultados para Radioactive prospecting


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With the development of oil and gas exploration, the exploration of the continental oil and gas turns into the exploration of the subtle oil and gas reservoirs from the structural oil and gas reservoirs in China. The reserves of the found subtle oil and gas reservoirs account for more than 60 percent of the in the discovered oil and gas reserves. Exploration of the subtle oil and gas reservoirs is becoming more and more important and can be taken as the main orientation for the increase of the oil and gas reserves. The characteristics of the continental sedimentary facies determine the complexities of the lithological exploration. Most of the continental rift basins in East China have entered exploration stages of medium and high maturity. Although the quality of the seismic data is relatively good, this areas have the characteristics of the thin sand thickness, small faults, small range of the stratum. It requests that the seismic data have high resolution. It is a important task how to improve the signal/noise ratio of the high frequency of seismic data. In West China, there are the complex landforms, the deep embedding the targets of the prospecting, the complex geological constructs, many ruptures, small range of the traps, the low rock properties, many high pressure stratums and difficulties of boring well. Those represent low signal/noise ratio and complex kinds of noise in the seismic records. This needs to develop the method and technique of the noise attenuation in the data acquisition and processing. So that, oil and gas explorations need the high resolution technique of the geophysics in order to solve the implementation of the oil resources strategy for keep oil production and reserves stable in Ease China and developing the crude production and reserves in West China. High signal/noise ratio of seismic data is the basis. It is impossible to realize for the high resolution and high fidelity without the high signal/noise ratio. We play emphasis on many researches based on the structure analysis for improving signal/noise ratio of the complex areas. Several methods are put forward for noise attenuation to truly reflect the geological features. Those can reflect the geological structures, keep the edges of geological construction and improve the identifications of the oil and gas traps. The ideas of emphasize the foundation, give prominence to innovate, and pay attention to application runs through the paper. The dip-scanning method as the center of the scanned point inevitably blurs the edges of geological features, such as fault and fractures. We develop the new dip scanning method in the shap of end with two sides scanning to solve this problem. We bring forward the methods of signal estimation with the coherence, seismic wave characteristc with coherence, the most homogeneous dip-sanning for the noise attenuation using the new dip-scanning method. They can keep the geological characters, suppress the random noise and improve the s/n ratio and resolution. The rutine dip-scanning is in the time-space domain. Anew method of dip-scanning in the frequency-wavenumber domain for the noise attenuation is put forward. It use the quality of distinguishing between different dip events of the reflection in f-k domain. It can reduce the noise and gain the dip information. We describe a methodology for studying and developing filtering methods based on differential equations. It transforms the filtering equations in the frequency domain or the f-k domain into time or time-space domains, and uses a finite-difference algorithm to solve these equations. This method does not require that seismic data be stationary, so their parameters can vary at every temporal and spatial point. That enhances the adaptability of the filter. It is computationally efficient. We put forward a method of matching pursuits for the noise suppression. This method decomposes any signal into a linear expansion of waveforms that are selected from a redundant dictionary of functions. These waveforms are chosen in order to best match the signal structures. It can extract the effective signal from the noisy signal and reduce the noise. We introduce the beamforming filtering method for the noise elimination. Real seismic data processing shows that it is effective in attenuating multiples and internal multiples. The s/n ratio and resolution are improved. The effective signals have the high fidelity. Through calculating in the theoretic model and applying it to the real seismic data processing, it is proved that the methods in this paper can effectively suppress the random noise, eliminate the cohence noise, and improve the resolution of the seismic data. Their practicability is very better. And the effect is very obvious.

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Oil and gas exploration of marine strata in China's Pre-Cenozoic residual basins is regarded as a worldwide puzzle because of existent problems and cruxes. Objectively speaking, the subsurface geologic structure is complicated, and the surface conditions of some areas are tough. On the other hand, there are still many problems to be solved in oil and gas exploration technologies of Pre-Cenozoic marine fades, and theoretic cognition about petroleum geology is not profound yet. Therefore, it is principal to explore integrated geophysical research ways of Pre-Cenozoic residual basins. Seismic prospecting and geophysical integrated interpretation technologies aimed at middle Paleozoic marine facies with deeper burial and complicated geologic conditions have not formed due to bad quality of deep strata data. Pre-Cenozoic strata, and especially extension, thickness and internal structure of Paleozoic strata can not be recognized from seismic profiles, so it is hard to systematically cognize structural features and oil-gas resources prospect of Pre-Cenozoic basins. To further investigation of fabric and structural features, basin prototype, formation and evolution pattern of Pre-Cenozoic basins, and also their control over formation, migration and aggregation of oil and gas, will play a guiding and promotive role in developing new surveying areas, selecting advantageous zones and predicting oil-gas resources.This paper follows the modem macrocontrol theory of "Region constrains local, deep strata controls shallow ones", and uses the integrated geophysical method of "One guide, two hinges, three combinations and multi feedbacks'*. Based on several years of geological and geophysical results of the Shengli Oilfield, and 14 newly-joint regional seismic profiles, deep structure and oil-gas bearing capacity of the Jiyang area are discussed and new cognitions are drawn as below.Seismic identification marks Tr, Tg, Tgl and Tg2 are established for importantPre-Cenozoic geological interfaces, and promoted to the whole Jiyang area.Through area-wide tracking and clogging of important seismic reflection marker,the isochronic framework of pre-Tertiary basin is set up in the Jiyang area for the firsttime, which is vital for basin research.Integrated with geological and geophysical research results, the Jiyang area isdivided into four first-order tectonic sequences- basement, lower tectonic layer,upper tectonic layer, and top tectonic layer. The basement and lower tectonic sequence which are related to Pre-Cenozoic are studied with emphasis.Through the research of regional seismic profiles, the point of view is given thatthe Kongdian Formation of Jiyang is structural transition period. The top-bottomunconformable interface of the Kongdian Formation is found out for the first time,and the basin model is determined primarily, which lay a basis for prototype basinresearch of the Jiyang Kongdian Formation.The distribution status of Middle-Paleozoic is delineated in the Jiyang area.The maximum thickness of Paleozoic lies in the top of the south declivity of half-graben. The thickness gets thinner towards the center of Mesozoic and Cenozoic half-graben basin, and even disappears. Structural action in the west-north affects the distribution of Paleozoic residual strata.6. The features of second-order tectonic sequence of the Jiyang depression isstudied and its evolution history of is rebuilt.Combined with the 5-stage evolution history of the China continent and structure evolution features of the Jiyang area, the structure sedimentary process since Paleozoic is divided into 5 periods - basement forming , Indosinian orogenic, Yanshan negative reversal, Himalayan extension and Neogene subsidence period.Combined with the research results of gravity, magnetic surveying and regionalprofiles, this paper brings forward the idea for the first time that the western boundaryof the Jiyang depression is the Ningjin-Yangpan fracture zone, and forms aside-column assemblage with the Wudi fracture zone.The opinion that under Middle-Cenozoic basins in the middle Jiyang area theremight superimpose an old residual basin is given for the first time. And if it is provedto be true, a new exploration space will be pioneered for Jiyang and even north China.There exists many types of tectonic-stratigraphic traps formed under piezotropy,extension and compound action in Pre-Cenozoic Jiyang. Therein all kinds of burialhills are the most important oil-gas trap type of Pre-Cenozoic, which should besurveyed layeredly according to the layout of oil sources.As such a new challenging project and field, the paper systematically analyses different geophysical responses of the Jiyang area, frames the deep structure of the area, and preliminarily recognizes the Pre-Cenozoic residual basins. It breaks through to a certain extent in both theory and practice, and is expected to provide new geophysical and geotectonic clues for deep exploration in Shengli.

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The reflection seismic prospecting technique is an important and a widely used method in the petroleum and coal surveying, and has been developed to a perfectly mature technique from the aspects of data acquisition, data processing to data interpretation. However, the metallic mine seismic prospecting, especially the high resolution seismic prospecting technique are being still in the course of studying and probing up to now. In this paper, the basic theory and the present situation of study on metallic mine seismic reflection are expatiated, the basic theory, the improving measure, the converging velocity and the ability on the integrating global optimization method are also illuminated in detail at first. Then the basic theory, the realization process and the practicing effects of the vector suppressing noise algorithm are also introduced. On the basis of studying of applying the integrating global optimization method to static correction and the vector suppressing noise algorithm, we elaborate processed the seismic data of Tongling metallic mine. We introduced the processing flow, the key steps and the processing effects. Basing on the processing results, we analyzed the major reflection characteristics, the geological interpretation results and the earth's crust top reflection structure and the space distribution status of Wutong set, the space shape of part lithological body and the contacting relations of horizonsunveiled.

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The seismic data acquisition system is the most important equipment for seismic prospecting. The geophysicists have been paying high attention to the specification of the equipment used in seismic prospecting. Its specification and performance are of great concerned to acquire precisely and accurately seismic data, which show us stratum frame. But, by this time, limited by the technology, most of the Broad-band Seismic Recorder (BSR) for lithosphere research of our country were bought from fremdness which were very costliness and maintained discommodiously. So it is very important to study the seismic data acquisition system.The subject of the thesis is the research of the BSR, several items were included, such as: seismic data digitizer and its condition monitor design.In the first chapter, the author explained the significance of the implement of BSR, expatiated the requirement to the device and introduced the actuality of the BSR in our country.In the second chapter, the collectivity architecture of the BSR system was illustrated. Whereafter, the collectivity target and guideline of the performance of the system design were introduced. The difficulty of the system design and some key technology were analyzed, such as the Electro Magnetic Compatibility (EMC), system reliability technology and so on.In the third chapter, some design details of BSR were introduced. In the recorder, the former analog to digital converter (ADC) was separated from the later data transition module. According to the characteristic of seismic data acquisition system, a set high-resolution 24-bit ADC chip was chosen to the recorder design scheme. As the following part, the noise performance of the seismic data channel was analyzed.In the fourth chapter, the embedded software design of each board and the software design of the workstation were introduced. At the same time the communication protocol of the each module was recommendedAt the last part of this thesis, the advantages and the practicability of the BSR system design were summarized, and the next development items were suggested.

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赤泥是氧化铝生产过程中的工业固体废弃物,具有强碱性和高放射性两个特点。目前赤泥的处置方法主要是建设赤泥堆场,供长期堆放,尚没有对其进行大规模利用的成熟技术。 随着铝工业的发展,亟需开发赤泥处置与资源化利用的新工艺技术。本论文运用环境地球化学的理论方法,采用化学分析、选矿分离、放射性测试等技术手段,对贵州铝厂拜耳法赤泥的放射性特征进行了矿物学研究,并利用铁钛着色机理生产赤泥墙体装修材料进行了应用试验研究,指明了赤泥规模化综合利用的途径。 通过研究,得到以下主要结论: 1)初步确定了赤泥放射性元素主要来源于铝土矿原矿,并赋存于原矿残留的锆石和独居石中。 2) 贵州铝厂拜耳法赤泥所含放射性偏高,倘若利用赤泥制作建筑主体材料,需要慎重考虑。 3)探讨了不同选矿方法对赤泥放射性强度的变化情况,重选、磁选、加磁粉磁选所得赤泥组分与赤泥原样放射性相比较,没有显著性差异。采用现有选矿技术,难以达到分离富集赤泥中含放射性组分。 4)利用拜耳法赤泥中富含Fe2O3和TiO2的着色机理,加入一定量的页岩可以制得金红-褐色系列颜色的彩色墙体装修材料。采用现有烧结砖厂一般生产工艺,利用拜耳法赤泥生产烧结制品,是规模化处理赤泥的一条可行途径。 本论文的研究结果指明了赤泥可行的利用途径是用于建材领域,为制定赤泥大规模资源化利用的技术路线提供了一定的理论基础。

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Measurement of antigen-specific T cell responses is an adjunctive parameter to evaluate protection induced by a previous Bordetella pertussis infection or vaccination. The assessment of T cell responses is technically complex and usually performed on fresh peripheral blood mononuclear cells (PBMC). The objective of this study was to identify simplified methods to assess pertussis specific T cell responses and verify if these assays could be performed using frozen/thawed (frozen) PBMC. Three read-outs to measure proliferation were compared: the fluorescent dye 5,6-carboxylfluorescein diacetate succinimidyl ester (CFSE) dilution test, the number of blast cells defined by physical parameters, and the incorporation of (3)H-thymidine. The results of pertussis-specific assays performed on fresh PBMC were compared to the results on frozen PBMC from the same donor. High concordance was obtained when the results of CFSE and blast read-outs were compared, an encouraging result since blast analysis allows the identification of proliferating cells and does not require any use of radioactive tracer as well as any staining. The results obtained using fresh and frozen PBMC from the same donor in the different T cell assays, including IFNγ and TNFα cytokine production, did not show significant differences, suggesting that a careful cryopreservation process of PBMC would not significantly influence T cell response evaluation. Adopting blast analysis and frozen PBMC, the possibility to test T cell responses is simplified and might be applied in population studies, providing for new instruments to better define correlates of protection still elusive in pertussis.

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An investigation of the potential environmental and health impacts in the immediate aftermath of one of the largest coal ash spills in U.S. history at the Tennessee Valley Authority (TVA) Kingston coal-burning power plant has revealed three major findings. First the surface release of coal ash with high levels of toxic elements (As = 75 mg/kg; Hg = 150 microg/kg) and radioactivity (226Ra + 228Ra = 8 pCi/g) to the environment has the potential to generate resuspended ambient fine particles (< 10 microm) containing these toxics into the atmosphere that may pose a health risk to local communities. Second, leaching of contaminants from the coal ash caused contamination of surface waters in areas of restricted water exchange, but only trace levels were found in the downstream Emory and Clinch Rivers due to river dilution. Third, the accumulation of Hg- and As-rich coal ash in river sediments has the potential to have an impact on the ecological system in the downstream rivers by fish poisoning and methylmercury formation in anaerobic river sediments.

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Wastewaters generated during hydraulic fracturing of the Marcellus Shale typically contain high concentrations of salts, naturally occurring radioactive material (NORM), and metals, such as barium, that pose environmental and public health risks upon inadequate treatment and disposal. In addition, fresh water scarcity in dry regions or during periods of drought could limit shale gas development. This paper explores the possibility of using alternative water sources and their impact on NORM levels through blending acid mine drainage (AMD) effluent with recycled hydraulic fracturing flowback fluids (HFFFs). We conducted a series of laboratory experiments in which the chemistry and NORM of different mix proportions of AMD and HFFF were examined after reacting for 48 h. The experimental data combined with geochemical modeling and X-ray diffraction analysis suggest that several ions, including sulfate, iron, barium, strontium, and a large portion of radium (60-100%), precipitated into newly formed solids composed mainly of Sr barite within the first ∼ 10 h of mixing. The results imply that blending AMD and HFFF could be an effective management practice for both remediation of the high NORM in the Marcellus HFFF wastewater and beneficial utilization of AMD that is currently contaminating waterways in northeastern U.S.A.

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The safe disposal of liquid wastes associated with oil and gas production in the United States is a major challenge given their large volumes and typically high levels of contaminants. In Pennsylvania, oil and gas wastewater is sometimes treated at brine treatment facilities and discharged to local streams. This study examined the water quality and isotopic compositions of discharged effluents, surface waters, and stream sediments associated with a treatment facility site in western Pennsylvania. The elevated levels of chloride and bromide, combined with the strontium, radium, oxygen, and hydrogen isotopic compositions of the effluents reflect the composition of Marcellus Shale produced waters. The discharge of the effluent from the treatment facility increased downstream concentrations of chloride and bromide above background levels. Barium and radium were substantially (>90%) reduced in the treated effluents compared to concentrations in Marcellus Shale produced waters. Nonetheless, (226)Ra levels in stream sediments (544-8759 Bq/kg) at the point of discharge were ~200 times greater than upstream and background sediments (22-44 Bq/kg) and above radioactive waste disposal threshold regulations, posing potential environmental risks of radium bioaccumulation in localized areas of shale gas wastewater disposal.

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OBJECTIVE: The diagnosis of Alzheimer's disease (AD) remains difficult. Lack of diagnostic certainty or possible distress related to a positive result from diagnostic testing could limit the application of new testing technologies. The objective of this paper is to quantify respondents' preferences for obtaining AD diagnostic tests and to estimate the perceived value of AD test information. METHODS: Discrete-choice experiment and contingent-valuation questions were administered to respondents in Germany and the United Kingdom. Choice data were analyzed by using random-parameters logit. A probit model characterized respondents who were not willing to take a test. RESULTS: Most respondents indicated a positive value for AD diagnostic test information. Respondents who indicated an interest in testing preferred brain imaging without the use of radioactive markers. German respondents had relatively lower money-equivalent values for test features compared with respondents in the United Kingdom. CONCLUSIONS: Respondents preferred less invasive diagnostic procedures and tests with higher accuracy and expressed a willingness to pay up to €700 to receive a less invasive test with the highest accuracy.

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Previous studies from this laboratory have shown that CNS myelin is phagocytized and metabolized by cultured rat macrophages to a much larger extent when myelin is pretreated with serum containing antibodies to myelin constituents than when it is left untreated or pretreated with non-specific serum. In this study the effect of cerebrospinal fluid (CSF) from rabbits with experimental allergic encephalomyelitis (EAE) in promoting myelin phagocytosis was examined. Fourteen rabbits were immunized with purified myelin in Freund's complete adjuvant, seven of which developed clinical EAE symptoms. Serum and CSF were collected from EAE and control rabbits, and the CSF was centrifuged to remove cells. Sera and CSF from these rabbits and from Freund's adjuvant-immunized controls and untreated controls were measured for IgG content by radial diffusion assay, their myelin antibody characteristics were analyzed by immunoblots, and the ability of these serum and CSF samples to promote myelin phagocytosis when used for myelin opsonization was examined. The ability of a CSF sample to enhance radioactive myelin uptake and phagocytosis by cultured macrophages as measured by the appearance of radioactive cholesterol ester was linearly proportional to its total IgG titer, and correlated approximately both with clinical symptoms of the animal and the presence of antibody against the myelin constituents myelin basic protein, proteolipid protein, and galactocerebroside. The cholesterol esterification activities of EAE sera correlated to a lesser extent with IgG levels and clinical symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)

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The definitive paper by Stuiver and Polach (1977) established the conventions for reporting of 14C data for chronological and geophysical studies based on the radioactive decay of 14C in the sample since the year of sample death or formation. Several ways of reporting 14C activity levels relative to a standard were also established, but no specific instructions were given for reporting nuclear weapons testing (post-bomb) 14C levels in samples. Because the use of post-bomb 14C is becoming more prevalent in forensics, biology, and geosciences, a convention needs to be adopted. We advocate the use of fraction modern with a new symbol F14C to prevent confusion with the previously used Fm, which may or may not have been fractionation corrected. We also discuss the calibration of post-bomb 14C samples and the available datasets and compilations, but do not give a recommendation for a particular dataset.

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La realidad del voluntariado es sumamente compleja hasta el punto de que resulta complicado definir y caracterizar el trabajo voluntario, dada la gran variedad de interpretaciones, motivaciones, variables sociodemográficas y aspectos culturales que configuran el perfil de los voluntarios. El objetivo de este trabajo es analizar la influencia conjunta de algunas variables sociodemográficas, así como de los valores culturales de índole secular o tradicional, sobre el perfil de los voluntarios en Europa. Además, se investiga qué variables orientan a los voluntarios hacia un determinado tipo de voluntariado u otro. Para ello se ha aplicado principalmente una metodología de regresión logística a partir de la información disponible en la European Value Study. Los resultados obtenidos ayudan a establecer una caracterización del voluntariado en Europa, y confirman la influencia de los valores culturales, en primer lugar, en la realización o no de trabajos de voluntariado, y en segundo lugar, en la elección que hacen estas personas del tipo de actividad con la que están comprometidos. Al analizar dos tipos de voluntariado de motivación supuestamente muy diferente, se concluye que existe un grupo de valores que influyen en ambos, aunque el sentido y la intensidad en la que lo hacen sea diferente; por otra parte, algunos valores tienen influencia o no en la realización de trabajos de voluntariado, dependiendo del tipo específico al que nos refiramos.

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This work deals with removal of Cesium (radioactive waste) in dilute aqueous phase by adsorption. Fullers earth was used as an adsorbent. The adsorption capacity of Fullers earth with respect to Cesium was found to be high, 26.3 mg / g of adsorbent.

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Iron and Mn redistribute in soil and saprolite during weathering. The geological weathering fronts ofcalcareous sedimentary rock were investigated by examining the bulk density, porosity, and distribution ofCa, Fe, and Mn. Core samples were taken ofsoil, saprolite, and bedrock material from both summit (HHMS-4B) and sideslope (HHMS-5A) positions on an interbedded Nolichucky shale and Maryville limestone landform in Solid Waste Storage Area 6 (SWSA-6). This is a low-level radioactive solids waste disposal site on the Dept. ofEnergy (DOE) Oak Ridge Reservation in Roane County Tennessee. This work was initiated because data about the properties of highly weathered sedimentary rock on this site were limited. The core samples were analyzed for pH, calcium carbonate equivalence (CCE), hydroxylamine-extractable (HA) Mn, and dithionite-citrate (CBD)-extractable Fe and Mn. Low pH values occurred from the soil surface down to the depth of the oxidized and leached saprolite in both cores. The CCE and HA-extractable Mn results were also influenced by the weathering that has occurred in these zones. Extractable Mn oxide was higher at a lower depth in the oxidized and leached saprolite compared with the Fe oxide, which was higher in the overlying soil solum. Amounts of Mn oxides were higher in the sideslope core (HHMS-5A) than in the summit core (HHMS-4B). Iron was more abundant in the deeper weathered summit core, but the highest value, 39.4 g kg-1, was found at 1.8 to 2.4 m in the sideslope core. The zone encompassing the oxidized and partially leached saprolite down to the unoxidized and unleached bedrock had higher densities and larger quantities of CaCO3 than the soil solum and oxidized and leached saprolite. The overlying soil and oxidized and leached saprolite had lower pH and CCE values and were higher in Fe and Mn oxides than the oxidized and unleached saprolite. The distribution of Fe and Mn is important when evaluating soil and saprolite for hazardous waste disposal site assessment.