bluuebunny/crossref_metadata_2025_split huggingface dataset:
An Improved Approach for Ensemble-Based Production Optimization
Authors: Chaudhri Masroor M. , Phale Hemant A. , Liu Ning , Oliver Dean S. 
Published: March 2009

Abstract
For oil reservoirs under water and/or gas drive, it is challenging and rewarding to effectively manage the water/gas fronts to maximize the sweep efficiency. In the past, a wide variety of approaches were developed and implemented for optimizing the reservoir performance by smartly adjusting operational controls. With recent developments in monitoring and control, the opportunity to optimize reservoir production through frequent adjustment of well controls has substantially increased. In this paper, we propose an improved ensemble-based approach for production optimization using Conjugate Gradient method (CGEnOpt). The proposed method results in faster convergence rate as a result of using the conjugate gradient directions instead of steepest ascent search directions. The net present value (NPV) of a single reservoir is optimized by obtaining the gradient of the NPV from an ensemble of control variables.
The effectiveness of the proposed method is demonstrated on a 3-D synthetic reservoir problem with 8 producers and 3 injectors. The production and injection rates are used as control variables to maximize NPV of the reservoir.
The results indicate that the control settings from the proposed method result in a significantly higher NPV of the reservoir as compared to the reference case. The number of iterations needed for the proposed method is significantly reduced compared to the standard ensemble-based optimization. The proposed method is able to allocate the production and injection rates effectively which results in a substantial decrease in the amount of water produced.
The proposed method is completely adjoint-free and is independent of the reservoir simulator used for the prediction simulation run which makes it fairly robust. Thus, it can be used with any existing simulator with minimal code development. The CGEnOpt technique is innovative for not requiring explicit computation of the gradient which makes it easy to implement.
Development and Application of a Fully-Coupled Thermal Compositional Wellbore Flow Model
Authors: Livescu S. , Aziz K. , Durlofsky L. J. 
Published: March 2009

Abstract
Thermal recovery processes are widely used for heavy oil production and are under investigation for other unconventional resources. The management and optimization of these processes require accurate representations of relevant physical phenomena in simulation models. An important aspect of the simulation capability is the modeling of flow in the wellbore and the coupling of wellbore and reservoir flows. In previous work, we developed and applied a black-oil thermal multiphase wellbore model and linked it to Stanford's General Purpose Research Simulator (GPRS). In this paper, we extend this formulation to treat thermal compositional systems. GPRS already contains a thermal compositional capability for reservoir flow; here we develop and test a thermal compositional wellbore model. This wellbore model includes an energy conservation equation, mass conservation equations for each component, and a general pressure drop relationship. The multiphase wellbore flow is represented using a drift-flux model, which includes slip between the three phases. The model determines the temperature, pressure, mixture flow velocity and component fractions as functions of time and axial position along the well. We apply the coupled thermal compositional wellbore-reservoir model to the simulation of several cases involving thermal effects. These include a verification example, in which we compare results from the compositional formulation to those of a black-oil model, and an example with seven components. Different well geometries (e.g., dual-lateral and deviated with varying inclination angle) are considered in these applications.
A Novel Method for Mapping Fractures and High Permeability Channels in Waterfloods Using Injection and Production Rates
Authors: Lee Kun-Han , Ortega Antonio , Nejad Amir Mohammad , Jafroodi Nelia , Ershaghi Iraj 
Published: March 2009

Abstract
This paper extends the work reported in SPE114222 for managing waterfloods using estimation of flow characteristics from only injection and production rates. The method first estimates the finite impulse response (FIR) curve corresponding to the fluid-flow between all injector-producer pairs. This FIR curve is analogous to the pressure curves obtained from pulse testing. Reservoir parameters, such as connectivity between wells, can be estimated from this curve, which can also be used to characterize variations of relative flow as a function of storage capacity (F-C plots), thus making it possible to quantify the heterogeneity of flow paths between wells.
Our proposed method is capable of identifying the flow channel relationships between all injector-producer well pairs. This helps in reservoir characterization, where information provided by the proposed procedure can describe the characteristics of flow-path between injector-producer pairs. It can also help in waterflood optimization by tracking sweep efficiency and balancing voidage-replacement. The method has been successfully tested and calibrated for simulated line drive patterns with various fracture geometry conditions. It successfully quantifies the interwell connectivity and the heterogeneous properties in the numerical simulations.
Our procedure has several advantages over pulse testing and tracer tests. In comparison to pulse testing, pressure data is not required and the only data needed are injection/production rates, which are often routinely available with high temporal resolution for many reservoirs. The quality of measured production rates affects the estimated properties. Because the proposed procedure can be routinely performed and implemented, the proposed procedure leads to a dynamic approach for reservoir and fluid flow mapping, where the results can be refined over time. Additionally, our procedure could also be used for better designs of pulse or tracer tests. Finally, once the flow channels are mapped, one can balance the flood and make diagnostic predictions about future response under any given injector scenarios.
Implementation of Efficient Plant Designs in a Time Constrained Market
Authors: Hoyer D. , Gray T. 
Published: March 2009

Abstract
This paper compares different energy conversion rates for some geothermal power plant cycles. These are being implemented at two high temperature, liquid dominated reservoirs; Kawerau and Rotokawa.
The power plant cycle selected for the first development is a dual flash, condensing steam turbine; however, optimisation with higher pressures and enthalpies resulted in a triple flash, condensing steam turbine for the second development. This will be the largest single cylinder geothermal steam turbine in the world. The project is currently under construction with commercial operation scheduled for the first half of 2010.
The environmental consent process in New Zealand provides a fixed average fluid extraction rate and an instantaneous maximum. Geothermal fluid conditions, (including; enthalpy, non-condensable gas content and chemistry) were defined from well test results and reservoir modelling. The owners’ financial model has been used to provide key metrics for selection of the plant cycle giving the maximum revenue from the consented geothermal fluid flow, considering life cycle costs. In one example, a triple flash cycle developed 6MW more than the comparable dual flash cycle, for which the economic benefit exceeded the additional capital and life cycle cost. Alternatives using multiple turbines were considered and interesting options developed. A risk review was completed to evaluate operating experience of similar equipment and design features.
Forecasting the Post-Fracturing Response of Oil Wells in a Tight Reservoir
Authors: Joo Jhiin , Wu Dongrui , Mendel Jerry M. , Bugacov Alejandro 
Published: March 2009

AbstractThis paper proposes a two-stage multi-system architecture for forecasting post-fracturing responses in a tight oil reservoir using historical fracturing data. The first stage predicts the 180-day cumulative liquid (oil + water) production directly, and the second stage uses differential correction to predict the prediction error resulting from the first stage. The final prediction is a combination of the two stages. 5-fold cross-validation is used in each stage, resulting in five forecasters for each stage. The average of the five predictions is taken as the output of the corresponding stage. Each of the five forecasters in each stage consists of three independent subsystems (Location, Completion and Fracturing), whose inputs are subsets of the well properties. The Location subsystem is constructed by a weighted average, whereas Completion and Fracturing are constructed by fuzzy logic systems. The parameters of the three subsystems are optimized simultaneously using simulated annealing. The final design achieved over 70% prediction accuracy for more than 96% of the testing wells. The main advantages of our approach are that 1) it does not require a large training dataset; 2) it can cope well with incomplete data entries and uncertainties; and, 3) the redundancy in the input parameters is used to improve accuracy.
Estimating the Price Effects of Non-Tariff Barriers
Authors: Dean Judith M , Signoret José E , Feinberg Robert M. , Ludema Rodney D. , Ferrantino Michael J 
Published: March 2009

Abstract
As multilateral negotiations focus more on reductions and removal of non-tariff barriers (NTBs), the importance of quantifying the impact of these barriers has increased. Recent studies have derived ad valorem equivalents for NTBs for a large number of countries and/or products, but the derivation has been indirect, due to either lack of price data or NTB incidence measures. This paper uses city level retail price data to directly estimate the average impact of core NTBs on prices of 47 consumer products, grouped into four separate sectors, for more than 60 countries in 2001. The analysis uses both government self-reported data and a new database of private sector complaint data to assess NTB incidence. A differentiated products model is used to capture imperfect substitutability between products. With city level price dataincluding both inter- and intra-country price differencesa more precise distinction can be made between the impact of NTBs and the impact of local distribution costs in raising price. The model is estimated using an instrumental variables approach to incorporate the endogeneity of NTBs. Results suggest that core NTBs are still highly restrictive in many countries and for many traded goods. While NTBs appear to be complements to tariffs, in some sectors the presence of a tariff reduces the price impact of the NTB. Results also suggest that in some sectors, the restrictiveness of NTBs is highly correlated with country income.
Effects of acyl donor type, catalyst type, and reaction conditions on the activity and selectivity of Friedel-Crafts acylation
Authors: Wolfson Adi , Madhusudhan Rao , Shapira-Tchelet Ayelet , Landau Miron 
Published: March 2009

AbstractAcylation of anisole and 3-methylanisole was performed with several acylating reagents (acetylation by AcCl and Ac2O and bromoacetylation by BrAcCl and (BrAc)2O) over different solid acid catalysts. The reaction conditions were optimized with respect to the acylation reagent, overall yield, solid acid catalyst, and the products selectivities. While acylation of anisole with acetyl chloride or acetic anhydride resulted in its full conversion to para-substituted acetophenone, the use of bromoacetyl bromide or bromoacetic anhydride yielded also the ortho-substituted product. Acylation of 3-methylanisole also yielded both para- and ortho-substitutions, and the products distribution was affected by the reaction conditions and catalyst type. It was found that while more acidic catalysts (caesium salt of heteropolyacid and zeolites) were the most active towards anisole acylation, the most active catalysts for the acylation of 3-methylanisole were ion-exchange catalysts. Employing HY-740 zeolite resulted in the highest ortho-selectivity in the acylation of anisole with bromoacetyl bromide and bromoacetic anhydride and in the acylation of 3-methylanisole with acetic anhydride.
Solid‐Supported Reagents for Synthesis of Nucleoside Monothiophosphates, Dithiodiphosphates, and Trithiotriphosphates
Authors: Ahmadibeni Yousef , Parang Keykavous 
Published: March 2009

AbstractThis unit describes procedures for the selective synthesis of nucleoside monothiophosphates, dithiodiphosphates, and trithiotriphosphates from solid‐supported phosphitylating reagents. Rigid and sterically hindered polymer‐bound 1,3,2‐oxathiaphospholane is reacted selectively with the 5′‐hydroxyl group of nucleosides in the presence of 1H‐tetrazole. Sulfurization in the presence of Beaucage's reagent (3H‐1,2‐benzodithiole‐3‐one 1,1‐dioxide) followed by ring‐opening with 3‐hydroxypropionitrile and basic cleavage in the presence of 1,8‐diazabicyclo[5.4.0]undec‐7‐ene (DBU) through the elimination of polymer‐bound ethylene episulfide afford nucleoside monothiophosphates. Furthermore, reaction of polymer‐bound diphosphitylating and triphosphitylating reagents, prepared from polymer‐bound benzyl alcohol, with unprotected nucleosides, sulfurization with Beaucage's reagent, and acidic cleavage using trifluoroacetic acid cocktail produce nucleoside dithiodiphosphates and trithiotriphosphates in moderate yields. Curr. Protoc. Nucleic Acid Chem. 36:13.9.1‐13.9.16. © 2009 by John Wiley & Sons, Inc.
Social learning and mother's behavior in manipulative tasks in infant marmosets
Authors: Dell'Mour Vera , Range Friederike , Huber Ludwig 
Published: March 2009

AbstractHigh levels of social tolerance are considered to promote social learning, as they allow direct observation of a manipulating conspecific and facilitate scrounging. Owing to tolerance toward infants, infancy is thought to be especially suited for learning socially transmitted behaviors. Despite this, few studies have investigated social learning of infants, particularly in manipulative tasks where observation might be most helpful. Here, we investigated (1) the influence of social learning on task acquisition in infant marmosets, and (2) whether the mother augments her behavior in a way that may enhance social learning by her infants. We tested infant and juvenile marmosets in four different complex foraging‐related tasks, featuring large living insects (two tasks) or artificially embedded prey (two tasks). Each individual observed the mother solving two of the tasks and served as a control in the other two tasks. Observers manipulated more and succeeded sooner than control animals, suggesting that observing the mother promoted learning either directly or by decreasing neophobia. Moreover, the data suggest that learning in 11–15 week‐old infants might be promoted actively by the mother. She solved the tasks, consumed less food, and consumed it later than when foraging with older offspring or alone. Furthermore, the results indicate the possible importance of the third and fourth month of infancy as the crucial ontogenetic period for social learning in marmosets, corroborating recent observations of free‐living common marmosets. Am. J. Primatol. 71:503–509, 2009. © 2009 Wiley‐Liss, Inc.
Titelbild: Compartmentalization of Chemically Separated Components into Droplets (Angew. Chem. 15/2009)
Authors: Edgar J. Scott , Milne Graham , Zhao Yiqiong , Pabbati Chaitanya P. , Lim David S. W. , Chiu Daniel T. 
Published: March 2009

AbstractElektroosmotische Tröpfchenerzeugung in Kombination mit Kapillarelektrophorese ermöglicht die Kompartimentalisierung molekularer Komponenten in einem Tröpfchenstrom, wie D. T. Chiu et al. in der Zuschrift auf S. 2757 ff. berichten und wie das Titelbild illustriert. Die tröpfchenweise separierten Banden können entweder auf einem Chip untersucht oder isoliert und einzeln analysiert werden.magnified image
Acrylic rubber/nitrile rubber blends: The effect of curatives on the mechanical, morphological, and dynamic mechanical properties
Authors: Celestino Micheli L. , de Oliveira Marlucy , Sirqueira Alex S. , Soares Bluma G. 
Published: March 2009

AbstractThe curing characteristics and mechanical properties of blends constituted by acrylic rubber (ACM) and nitrile rubber (NBR) were investigated. The curing process was performed by a combination of curing systems specific for each rubber component. The curing system for the ACM phase consisted of hexamethylene diamine carbamate/sodium stearate, whereas the NBR phase was cured with different systems: accelerated sulfur or bismaleimide/peroxide. In all of the curing systems employed, the blends presented more outstanding ultimate tensile properties than the individual rubbers, which indicated a compatibilization effect of the curing systems. Dynamic mechanical analysis of the blends revealed a broadening of tan δ peak and a shift in the glass‐transition temperature of the ACM phase in the direction of the NBR transition in most of the systems studied and an increase in the storage modulus, which was also an indication of a compatibilization effect. Scanning electron microscopy also revealed a very thin rubber phase, which confirmed the compatibilization. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Monitoring cure in epoxies containing carbon nanotubes with an optical‐fiber Fresnel refractometer
Authors: Dimopoulos Athanasios , Buggy Stephen J. , Skordos Alexandros A. , James Stephen W. , Tatam Ralph P. , Partridge Ivana K. 
Published: March 2009

AbstractFresnel refractometry was used to follow the changes in the refractive index during the isothermal curing of a simple difunctional epoxy resin, a commercial formulated multifunctional epoxy blend, and the same two resin systems modified by the addition of multiwalled carbon nanotubes. The refractive index change, monitored via an embedded optical fiber, was correlated with the degree of cure established from isothermal differential scanning calorimetry measurements. A good correlation was established in all cases, indicating the potential of the technique to be used for online cure monitoring in thermosetting resin carbon nanocomposites. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Venom of Pteromalus puparum (Hymenoptera: Pteromalidae) induced endocrine changes in the hemolymph of its host, Pieris rapae (Lepidoptera: Pieridae)
Authors: Zhu Jia‐Ying , Ye Gong‐Yin , Dong Sheng‐Zhang , Fang Qi , Hu Cui 
Published: March 2009

AbstractPteromalus puparum is a predominant endoparasitoid wasp of Pieris rapae. Its venom is the only active factor injected into host associated with oviposition. In this report, we explored whether the venom alone from this wasp affects the endocrine system of its host or not. We monitored the changes of hemolymph juvenile hormone (JH; only JH III detected), ecdysteroid, and juvenile hormone esterase activity (JHE) over 72 h in parasitized and venom‐microinjected P. rapae pupae. Non‐parasitized and PBS‐microinjected P. rapae served as controls. Results showed that JH titers were significantly higher in parasitized and venom‐microinjected pupae than that in control pupae during 24 to 72 h. After 12 h, JH titers were significantly promoted by parasitization and venom microinjection. JHE activities of non‐parasitized and PBS‐microinjected pupae were significantly higher than that of parasitized and venom‐microinjected pupae, which was with a peak at 12 h (parasitized pupae) or 24 h (venom‐microinjected pupae) during 6 to 48 and 12 to 36 h, respectively. The hemolymph titers of ecdysteroid in non‐parasitized and PBS‐microinjected pupae increased rapidly during 12 to 36 h with a peak at 36 h, and were higher than treatments before 48 h, while presenting a significant difference at 24 to 48 h between the treatments and controls. The results demonstrate that venom alone of this parasitoid wasp can disrupt its host's endocrine system. © 2009 Wiley Periodicals, Inc.
Revisiting the concept of lineage in prokaryotes: a phylogenetic perspective
Authors: Boucher Yan , Bapteste Eric 
Published: March 2009

AbstractMutation and lateral transfer are two categories of processes generating genetic diversity in prokaryotic genomes. Their relative importance varies between lineages, yet both are complementary rather than independent, separable evolutionary forces. The replication process inevitably merges together their effects on the genome. We develop the concept of “open lineages” to characterize evolutionary lineages that over time accumulate more changes in their genomes by lateral transfer than by mutation. They contrast with “closed lineages,” in which most of the changes are caused by mutation. Open and closed lineages are interspersed along the branches of any tree of prokaryotes. This patchy distribution conflicts with the basic assumptions of traditional phylogenetic approaches. As a result, a tree representation including both open and closed lineages is a misrepresentation. The evolution of all prokaryotic lineages cannot be studied under a single model unless new phylogenetic approaches that are more pluralistic about lineage evolution are designed.
MeCP2 post‐translational regulation through PEST domains: two novel hypotheses
Authors: Thambirajah Anita A. , Eubanks James H. , Ausió Juan 
Published: March 2009

AbstractMutations in the methyl‐CpG‐binding protein 2 (MeCP2) cause Rett syndrome, a severe neurodevelopmental disease associated with ataxia and other post‐natal symptoms similar to autism. Much research interest has focussed on the implications of MeCP2 in disease and neuron physiology. However, little or no attention has been paid to how MeCP2 turnover is regulated. The post‐translational control of MeCP2 is of critical importance, especially as subtle increases or decreases in MeCP2 amounts can affect neuron morphology and function. The latter point is of particular importance for gene therapeutic approaches in which exogenous wild‐type MeCP2 is being introduced into diseased neurons. Further to this, we propose two hypotheses. The first hypothesis discusses the poly‐ubiquitin‐mediated post‐translational regulation of MeCP2 through its two PEST domains. The second hypothesis explores the use of histone deacetylase inhibitors to modulate the amounts of MeCP2 expressed in conjunction with the aforementioned therapeutic approaches.
How did parasitic worms evolve?
Authors: Viney Mark E. 
Published: March 2009

AbstractNematodes are important parasites of humans and other animals. Nematode parasitism is thought to have evolved by free‐living, facultatively developing, arrested larvae becoming associated with animals, ultimately becoming parasites. The formation of free‐living arrested larvae of the nematode Caenorhabditis elegans is controlled by the environment, and involves dafachronic acid (DA) and transforming growth factor (TGF)‐β signalling. Recent data have shown that DA acid signalling plays a conserved role in controlling larval development in both free‐living and parasitic species. In contrast, TGF‐β signalling does not seem to be conserved; this difference perhaps points to how nematode parasitism did evolve.