bluuebunny/crossref_metadata_2025_split huggingface dataset:
1,3-Digerma-2-gallata- and -indataallenic Anions: The First Compounds with Ge=Ga or Ge=In Double Bonds
Authors: Nakata Norio , Izumi Rika , Lee Vladimir Ya , Ichinohe Masaaki , Sekiguchi Akira 
Published: October 2008

Abstract
The novel allenic anions consisting of two germanium atoms and a gallium or indium atom, 1,3-digerma-2-gallata- and -indataallenic anions, [(t-Bu2MeSi)2Gt-Bu2)2]−·[Li+(thf)4] (3a: M=Ga, 3b: M=In) were synthesized by the reaction of the dilithiogermane, (t-Bu2MeSi)2GeLi2 (2) with 0.5 equiv of GaCl3 or InCl3. A crystal structure analysis of 3b showed that the &gt;Ge–In–Ge&lt; framework is bent (158.451(14)°) with the two Ge=In bond lengths (2.5453(4) and 2.5387(4) Å).Ge(SiMe
Reconfirmation of Recognition Site in Composites of Imprinted β-Cyclodextrin Polymer/Solid Support as Stationary Phase of HPLC
Authors: Nagaoka Suguru , Song Shi-hui , Sumaoka Jun , Komiyama Makoto 
Published: October 2008

Abstract
β-Cyclodextrin (β-CyD) was imprinted to a tripeptide H–Phe–Lys–Phe–NH2 on the surface of modified silica-gels, alumina, and Poly-HEMA [poly(hydroxyethyl methacrylate)]. In spite of notable differences in surface charges and other physicochemical properties of these solid supports, all the imprinted β-CyD polymers showed notable imprinting effects, confirming the overwhelming roles of ordered assemblies of β-CyD for the molecular recognition.
Modification Effect of SCN− Ions on the Morphology of α-Fe2O3 Nanoparticles
Authors: Lv Baoliang , Xu Yao , Wu Dong , Sun Yuhan 
Published: October 2008

Abstract
Based on the concentration difference of exposed dangling Fe3+ ions on different crystal facets, an “oriented dissolution” along2O3 was carried out via a redox reaction between coordinative ions SCN− and exposed Fe3+ ions. It is a new effective route to modify the morphology of α-Fe2O3 nanoparticles.direction of α-Fe
A Novel One-step Photocatalytic Synthesis of Benzo[d]oxazol-2(3H)-one with C-doped TiO2 Nanoparticle
Authors: Wang Huqun , Zhang Zhimin , Chang Wenfu 
Published: October 2008

Abstract
A novel approach was proposed to synthesize benzo[d]oxazol-2(3H)-one by photoreduction of o-nitrophenol and cyclization with urea using C-doped TiO2 nanoparticles as photocatalyst which was prepared by a modified sol–gel method using glucose as carbon source.
Least-Squares-basierte Ableitungsschätzung: Theorie und Einstellregeln für den praktischen Einsatz Least Squares based Derivative Estimation: Theory and Tuning Rules for the Practical Application
Authors: Mai Philipp , Hillermeier Claus 
Published: October 2008

Zusammenfassung
In diesem Artikel wird das bekannte Ableitungsschätzverfahren mittels Least-Squares, welches auf polynomialer Approximation des verrauschten Messsignals beruht, im Hinblick auf seine stochastischen Eigenschaften und die auftretende Zeitverzögerung untersucht. Anhand des fehlertoleranten Aufschwingens des Inversen Pendels werden die Ergebnisse experimentell bestätigt.
Long-term and acute effects of zinc contamination of a stream on fish mortality and physiology
Authors: Giardina Andrea , Larson Sandra F. , Wisner Brian , Wheeler John , Chao Matthew 
Published: October 2008

Abstract
A section of the Upper Enoree River in South Carolina, USA, was contaminated with chemical waste in 1985, and high concentrations of zinc persist decades later. In this study, we examined the zinc concentrations in the water, the accumulation of zinc in a variety of fish tissues, the effects of the contaminated water on fish sperm motility in vitro, and the mortality rates of introduced fish. Zinc concentrations in the water samples collected from six sites decreased as distance from the spill site increased, ranging from 7.3 to 0.34 mg/L (p &lt; 0.001). The zinc concentrations of tissues from native fish were highest in liver (mean across sites of 110 ppm/g tissue) and gills (77.4 ppm/g tissue), followed by gonads (30.7 ppm/g tissue) and muscle (6.9 ppm/g tissue) (p &lt; 0.001). The duration of fast motility of Salmo trutta sperm was significantly diminished in sperm activated in samples from the contaminated stream compared with the control stream (p &lt; 0.05). To further evaluate the ability of fish to survive at the sites with different zinc concentrations, groups of Gambusia holbrooki were placed in traps at a reference site (uncontaminated local tributary), and three sites along the contaminated stream. Rapid mortality was observed in the two sites closest to the spill, including one site in which native fish had been found. The introduced G. holbrooki expressed higher zinc concentration in gills than gonads or muscle (p &lt; 0.001), and water zinc concentration significantly affected fish mortality (p &lt; 0.001). The results from these experiments indicate that zinc contamination of streams can have sublethal effects on populations and physiology of fish that are able to survive in the contaminated water.
Uptake and elimination of hydrophobic organic contaminants in estuarine copepods: An experimental study
Authors: Cailleaud Kévin , Budzinski Hélène , Menach Karyn Le , Souissi Sami , Forget-Leray Joëlle 
Published: October 2008

AbstractPolycyclic aromatic hydrocarbons (PAHs) are considered to be rapidly biotransformed by organisms, whereas poly-chlorinated biphenyls (PCBs) are strongly bioaccumulated. In the present study, the estuarine copepod Eurytemora affinis was exposed in a continuous flow-through system to dissolved PAH (500 ng/L) and PCB (300 ng/L) mixtures for 86 h, whereas control groups were placed in a continuous flow-through system with clean water. Both PCB and PAH body residues were measured and compared in exposed and in nonexposed copepods to assess the uptake and the elimination of these two contaminant classes in this copepod species. After the exposure, exposed copepods exhibited concentration factors, based on a dry-weight basis, of 25, 750, and 1,200, respectively, for total PCBs and PAHs. The lower concentrations of PAHs in the nonexposed versus exposed copepods in contrast to small differences for PCBs suggest a higher rate of metabolism of PAHs compared with PCBs and could explain the differences observed in the accumulation. Furthermore, uptake as well as elimination of both PCBs and PAHs were compound selective in E. affinis. Therefore, higher-molecular-weight PCBs and PAHs were preferentially accumulated, while lower-molecular-weight compounds were preferentially eliminated. These results suggest the importance of copepods in the biogeochemical cycles of hydrophobic organic contaminants in estuarine ecosystems.
Feather growth influences blood mercury level of young songbirds
Authors: Condon Anne M. , Cristol Daniel A. 
Published: October 2008

Abstract
Dynamics of mercury in feathers and blood of free-living songbirds is poorly understood. Nestling eastern bluebirds (Sialia sialis) living along the mercury-contaminated South River (Virginia, USA) had blood mercury levels an order of magnitude lower than their parents (nestling: 0.09 ± 0.06 mg/kg [mean ± standard deviation], n = 156; adult: 1.21 ± 0.57 mg/kg, n = 86). To test whether this low blood mercury was the result of mercury sequestration in rapidly growing feathers, we repeatedly sampled free-living juveniles throughout the period of feather growth and molt. Mean blood mercury concentrations increased to 0.52 ± 0.36 mg/kg (n = 44) after the completion of feather growth. Some individuals had reached adult blood mercury levels within three months of leaving the nest, but levels dropped to 0.20 ± 0.09 mg/kg (n = 11) once the autumn molt had begun. Most studies of mercury contamination in juvenile birds have focused on recently hatched young with thousands of rapidly growing feathers. However, the highest risk period for mercury intoxication in young birds may be during the vulnerable period after fledging, when feathers no longer serve as a buffer against dietary mercury. We found that nestling blood mercury levels were not indicative of the extent of contamination because a large portion of the ingested mercury ended up in feathers. The present study demonstrates unequivocally that in songbirds blood mercury level is influenced strongly by the growth and molt of feathers.
Acoustic Leak Monitoring on Subsea Valves
Authors: Instanes Geir , Pedersen Audun 
Published: October 2008

Abstract
Acoustic leak monitors in mechanical contact with components of special interest have clear advantages over many alternatives, in particular for continuous monitoring over time or during specific operations. Non-invasiveness and repeatability are among the most important benefits of this technology. In connection with a delivery of self-contained, battery operated subsea leak monitors, the technology was demonstrated in a laboratory environment. A 20″ subsea valve was fitted with acoustic leak monitors, pressure sensors and a mass flow meter. Artificial damages were made to the valve in three incremental steps. One port was pressurized with nitrogen, and the resulting leakage flow was detected and quantified. Detection thresholds as low as 1 SCM/h were observed in the demonstration. Higher thresholds are however predicted for most field situations.
New High-Temperature Optical Fiber Technology Successfully Provides Continuous DTS Data under Severe SAGD Conditions
Authors: Kaura Jiten , Sierra Jose , Park Bob 
Published: October 2008

Abstract
The use of optical fibers in the oil and gas industry is becoming more viable for several applications, particularly in permanent reservoir monitoring, such as distributed temperature sensing (DTS) and optical pressure transducers. However, poor long-term performance of fibers, especially at elevated temperatures, is still an issue yet to be fully resolved. This problem is critically important in steam assisted gravity drainage (SAGD) applications, where wells operate in extreme conditions of high temperatures, often exceeding 250°C, as well as in high pressures within a hydrogen-rich environment. Optical fiber performance is seriously affected by many factors, including: Hydrogen ingressionThermal resistance of the materialsMechanical resistance of the fiber
Exposure of optical fibers to hydrogen changes the performance of the fibers through what is referred to in the industry as "hydrogen aging" or "hydrogen darkening." Hydrogen darkening is increased absorption or light loss due to various chemical species in the glass fiber resulting from the presence of hydrogen.
The Reservoir Suitability Studies of Nitrogen Foam Flooding in Shengli Oilfield
Authors: Liu Renjing , Liu Huiqing , Li Xiusheng , Fan Zhicheng 
Published: October 2008

Abstract
Many previous researches have proved that foam can increase the sweep efficiency and control gas mobility, and thus increase oil recovery. However, research on the effects of reservoir conditions such as the permeability, reservoir heterogeneity, formation rhythm and the viscosity of prude oil remains incomplete. Therefore, it is significant to study the foam efficiency in different reservoir conditions for large scale application of foam flooding.
The foaming agent was evaluated in laboratory and flooding experiments were conducted upon two groups of long real formation cores from Shengli oilfield to study foam flooding efficiencies. The effects of core permeability and gas liquid ratio on foam resistance factor were discussed. And then operating parameters including gas liquid injection ratio, injection rate and foam injection time were optimized and the influence of reservoir heterogeneity, the viscosity of crude oil and formation rhythm on nitrogen foam flooding efficiency were investigated at length by means of numerical simulation in the light of Shengli specific reservoir conditions.
The results show that, nitrogen foam flooding has excellent blocking ability and the optimum ratio of gas to liquid is 1.5:1; and the optimum foam rate is0.2 pore volume; the best foam flooding time is when the water cut of production well is 85%~ 90%. Nitrogen foam flooding is more effective for heterogeneous formations rather than for homogeneous ones. Furthermore, the efficiency of the flooding system decreases with the increasing viscosity of crude oil and is better in regular rhythm formation than that in negative rhythm formation. Finally, some easy-to-use and practical charts are drawn to analyze the economic benefits of nitrogen foam flooding for the given reservoir.
The study results provide a set of reservoir criteria that can be used as guidelines to choose potential reservoir candidates for nitrogen foam flooding.
Moving from Vision to Reality – The State of Optimal Value Testing
Authors: Elshahawi Hani , Hite Robert H. , Hows Melton P. 
Published: October 2008

Abstract
Over the past few years, there has been a vision in Shell that Optimal Value Testing (OVT) would some day replace conventional drill stem tests for in-situ measurement of dynamic reservoir properties such as permeability and drainage volume. This vision is that OVT would be safer, less costly, and friendlier to the environment, but the key impediment to OVT was that the quality of the results might be inadequate for the difficult development decisions that we face.
Definitions of OVT may vary, but in Shell we define it as the testing method that yields fit-for-purpose results with the lowest cost and HSE impact. In more pragmatic terms, it is any pressure transient test in which live hydrocarbons are not produced directly to surface. Currently we have three types of well tests in our OVT toolbox – wireline formation testers, the closed system test with cleanup and repeat surges, and injectivity testing. We have recent examples of closed system tests and wireline formation tests that show we can get comparable data quality to a conventional DST. Injection testing, aimed at determining drainage volume, is less mature and we have yet to execute an injection test. However, there has been considerable design work that makes us believe, given the recent experience with closed chamber systems, that that technology can also be successful.
This paper describes the strengths, weaknesses, and opportunities of each OVT type. We present several examples of design, execution, and analysis of these tests. The technology is immature, and there are more issues to resolve than with a conventional drill stem testing. However, by drawing on our increasing breadth of experience, future value of information decisions we take about doing in-situ dynamic measurements will more often include the cheaper, safer, and more environmentally friendly OVT.
Steam Flooding Field Fault Reactivation Maximum Reservoir Pressure Prediction Using Deterministic and Probabilistic Approaches
Authors: Yi X. 
Published: October 2008

Abstract
Fault reactivation induced by excessive reservoir steam pressure in heavy oil fields is suspected as one of the possible perpetrators that caused steam eruption to the surface. This can lead to significant financial losses related to environment cleanup and curtailed oil production. A traditional approach to fault reactivation prediction provides a deterministic critical reservoir pressure without proper regard to the uncertainties in the model input parameters and the predicted results. A probability distribution of the fault reactivation maximum reservoir pressure provides a better means to calculate a risk weighted Expected Net Present Value for management to make better decisions on steam flooding and to anticipate potential consequences.
In this study, a geomechanical model was established for the Batang Field, Central Sumatra, Indonesia. Using the geomechanical model, first, a fault seal analysis was performed and indicated that all faults were sealed in sands under initial stress and pore pressure conditions. Second, fault reactivation reservoir pressures for major faults in the field were predicted assuming a frictional sliding frictional coefficient of 0.5, which was derived using frictional faulting theory by a geomechanics services provider for the nearby Duri Field. Two scenarios were run in this case. One assumed a stress path coefficient of zero for horizontal stresses (decoupled); the other assumed a stress path coefficient of 0.4 (coupled). It was found that the coupling of stress and reservoir pressure provides a less conservative value of maximum reservoir pressure. Lastly, Monte Carlo simulations were run to consider the uncertainties of frictional sliding coefficient, and especially the stress path coefficient among the input parameters. It was found that the results from Monte Carlo simulations and deterministic approach were largely consistent but the resulting probability distribution from the Monte Carlo simulation approach provides significantly more information.
Determination of Gas Well Deliverability in Volcanic Gas Reservoir Using Transient Testing Data
Authors: Qinglong Xu , Rui Shao , Shiquan Yu , Baizhou Fu 
Published: October 2008

Abstract
Quite a few large-scale volcanic gas reservoirs have been discovered in deep zone in Songliao Basin of North-East China in recent years. The consequent issue is how to produce this kind of gas reservoir effectively. The interpretive principle and method of gas well multi-point open flow potential test demands that testing technology meet sustained measuring condition, while during actual productivity testing, productivity and bottomhole pressure is not steady yet affected by various reasons, these testing multi-point open flow potential test data can not use conventional productvity analysis method to calculate, especially Daqing deep volcanic gas reservoir is low permeability gas reservoir, productvity testing needs a long steady time, so testing cost is very high. The article is aimed at unsteady testing productivity or bottomhole pressure condition, deduction a new evaluation of gas well productvity equation in theory, base on unsteady seepage theory, using pressure superposition principle deduce variable production rate unsteady seepage gas well binomial productvity equation expressed with pressure square, present relevant analysis method of gas well productivity. This method can save a lot of testing time, improve data utilization factor, provide us a credible method to establish gas well productivity of low permeability gas field.
Gas Monetization for Sustainable Development, The Trinidad and Tobago Experience
Authors: Baksh Timmy 
Published: October 2008

Abstract
Developing new gas markets is a long-term undertaking. It is this thinking that has driven the actions of the Government of Trinidad and Tobago to deliberately pursue a strategy of gas market development. The success story of Trinidad and Tobago's ability to monetize it's hydrocarbon resources is unique and Trinidad and Tobago is one of a few countries that has developed a successful formula to monetize gas in a comprehensive manner, by developing broad-based domestic consumptive industries and also a direct export market in LNG.
The global energy market is very dynamic and the demand for energy, when considering security of supply, safety and the environment, is constantly shifting. Trinidad and Tobago, through aggressive policy initiatives and institutional strengthening of the regulatory agency, has been able to successfully adapt to this volatile global market. This paper will examine the various policies and discuss the restructuring of the regulatory agency within Trinidad and Tobago.
Trinidad and Tobago has built a large and diversified market for natural gas and is one of the most diversified gas-based petrochemicals centres in the Americas. This successful formula for monetization and sustainability has become known as the Trinidad and Tobago Model. This paper will seek to elaborate on this Model and examine the various development strategies pursued, which has successfully lead sustainable and diversified industrialization within the energy sector of the country.
This paper will also focus on the strategic geographical location of Trinidad and Tobago and how the Country has and is continuing to foster regional and international energy and gas-integration ventures. Trinidad and Tobago is well endowed with hydrocarbon reserves and has positioned itself as one of the emerging markets in the Western Hemisphere. This paper will provide an insight on Trinidad and Tobago position as a key player in the global energy market.
Appropriate Assessment of Gas-Liquid Slippage – A Critical Step from a Good Production Logging Survey to a Successful Workover for Gas Wells
Authors: Ouyang Liang-Biao , Suthichoti Polpipat 
Published: October 2008

Abstract
Production logging (PLT) has been routinely applied in oil and gas industry to estimate phase production profile, determine oil/gas/water producing layers, and detect major fluid entry or exit. Through successful PLT surveys and appropriate interpretation, it may also be possible to identify thief zones and high perm channels, locate injected fluid breakthrough, monitor fluid front movements, detect crossflow and fluid migration, assist in reservoir simulation studies, etc.
Subsequent workover operation following a PLT run is frequently performed aiming at reducing water production while maintaining/increasing oil and/or gas production. Unfortunately, in practice, mixing results have been obtained through workover operations designed based on PLTs, due to poor logging procedure, unreasonable PL tool selection, poorly executed surveys, inappropriate interpretation, etc.
In the presence of multiphase flow in a well, interpretation of production logs becomes critical for achieving successful estimate of major fluid entries and thus successful workover operation. Appropriate interpretation of production logs relies heavily on the selection of a reasonable multiphase flow model to correctly estimate gas-liquid slippage and capture complex multiphase flow features.
In this paper, the major flow characteristics of multiphase flow in a wellbore will first be described. Different correlations/models to describe multiphase flow and calculate slippage will then be introduced; the pros and cons of each correlation/model will be highlighted. The impacts of multiphase flow model selection and gas-liquid slippage assessment on the interpretation results of production logs will be investigated.
Field case histories will be described to illustrate the critical roles played by reasonable gas-liquid slippage assessment in production log interpretation. PLT interpretation based on different slippage assessments will be shown and compared with actual workover results. Guidelines for appropriate gas-liquid slippage assessment for production log interpretation will be provided and key lessons learned shared.