bluuebunny/crossref_metadata_2025 huggingface dataset:
Solid-State Digital Micro-Mirror Array Spectrometer for Hadamard Transform Measurements of Glucose and Lactate in Aqueous Solutions
Authors: Xiang Dong , Arnold Mark A.
Published: October 2011

A novel solid-state near-infrared spectrometer is presented based on a digital micro-mirror array device (DMD) that is well designed for Hadamard transform spectroscopy. This spectrometer is designed for the collection of transmission spectra over the C–H first overtone region of the near-infrared spectrum (6500–5500 cm−1). A spectral resolution of 2.2 nm (∼11 cm−1) is realized by using a 25 μm diameter linear tungsten filament as the source. Such a thin filament reduces imaging aberrations into the micro-mirror array, thereby enhancing spectral resolution. After passing through the sample, the transmitted radiation is dispersed with a grating before being imaged onto the surface of the DMD. Hadamard transform masks are implemented through the DMD and the reflected light is monitored by a single-element photodiode detector. The analytical utility of this approach is demonstrated through the multivariate quantification of glucose and lactate in binary mixtures composed in an aqueous buffer solution. A signal-to-noise ratio of 35000 is achieved through these aqueous samples, and the resulting quantitative measurements provide a standard error of prediction of 1.4 and 0.9 mM for glucose and lactate, respectively. The selectivity of the resulting calibration models is established by using both a pure component selectivity analysis as well as analysis of the net analyte signal for each component. These quantitative results from the DMD Hadamard transform spectrometer compare favorably to similar measurements performed with a commercial Fourier transform spectrometer.
Calculation of Optical Thicknesses of Magnesium Emission Spectral Lines for Diagnostics of Laser-Induced Plasmas
Authors: Pace Diego M. Díaz , D'Angelo Cristian A. , Bertuccelli Graciela
Published: October 2011

In this work, plasma characterization by laser-induced breakdown spectroscopy (LIBS) has been investigated. We propose a method based on the calculation of the optical thicknesses of emission spectral lines in the framework of a homogeneous optically thick plasma in local thermodynamic equilibrium (LTE). In this approach, self-absorption is taken into account to retrieve the optically thin intensities and plasma characterization is achieved. The developed procedure is applied to magnesium (Mg) lines measured from plasmas generated in air at atmospheric pressure from calcium hydroxide samples using an infrared Nd:YAG laser. The influence of laser irradiance on both plasma shape and emission intensity was studied to select the most suitable experimental conditions. Spectral lines of Mg I–II were measured and analyzed for different laser energies, delay times, and concentrations of the analyte. In each case, the plasma temperature, the electron density, and the parameters Nl were determined, without employing curves-of-growth. The results obtained showed the practical usefulness of the method to provide valuable information in LIBS experiments.
Time-Resolved Resonance Raman Spectroscopy: Exploring Reactive Intermediates
Authors: Sahoo Sangram Keshari , Umapathy Siva , Parker Anthony W.
Published: October 2011

The study of reaction mechanisms involves systematic investigations of the correlation between structure, reactivity, and time. The challenge is to be able to observe the chemical changes undergone by reactants as they change into products via one or several intermediates such as electronic excited states (singlet and triplet), radicals, radical ions, carbocations, carbanions, carbenes, nitrenes, nitrinium ions, etc. The vast array of intermediates and timescales means there is no single “do-it-all” technique. The simultaneous advances in contemporary time-resolved Raman spectroscopic techniques and computational methods have done much towards visualizing molecular fingerprint snapshots of the reactive intermediates in the microsecond to femtosecond time domain. Raman spectroscopy and its sensitive counterpart resonance Raman spectroscopy have been well proven as means for determining molecular structure, chemical bonding, reactivity, and dynamics of short-lived intermediates in solution phase and are advantageous in comparison to commonly used time-resolved absorption and emission spectroscopy. Today time-resolved Raman spectroscopy is a mature technique; its development owes much to the advent of pulsed tunable lasers, highly efficient spectrometers, and high speed, highly sensitive multichannel detectors able to collect a complete spectrum. This review article will provide a brief chronological development of the experimental setup and demonstrate how experimentalists have conquered numerous challenges to obtain background-free (removing fluorescence), intense, and highly spectrally resolved Raman spectra in the nanosecond to microsecond (ns–μs) and picosecond (ps) time domains and, perhaps surprisingly, laid the foundations for new techniques such as spatially offset Raman spectroscopy.
Export Promotion Strategy and Performance: The Role of International Experience
Authors: Hultman Magnus , Katsikeas Constantine S. , Robson Matthew J.
Published: October 2011

This study examines how international experience shapes managerial judgment in the formation of effective export promotion strategies. Drawing from contingency theory and the organizational learning perspective, the authors develop and test a model of the effects of different forms of international experience—duration, scope, and intensity—on the performance outcomes of promotion adaptation. Using data from 336 export ventures, the authors find that promotion adaptation relates positively to performance when duration is short and intensity is low, but there is a nonsignificant moderating effect for scope. However, the subsequent analysis suggests that scope, together with sociocultural distance and promotion adaptation, exerts a complex three-way effect on export performance, highlighting the need for more research attention in this area.
Research on Half of the Bandwidth of the En-/Decoding Spectrum Application Based on SSFBG
Authors: FenFei Hou
Published: October 2011

A scheme for half of the bandwidth of the en-/decoding spectrum application based on superstructured fiber Bragg grating (SSFBG) is presented in this paper. As verified by theoretical and simulation analysis, the half of the bandwidth of the en-/decoding spectrum has already contained all code information and en-/decoding function can be completed as long as the reflection spectrum covers half of the original bandwidth (half of the bandwidth of the en-/decoding spectrum). As indicated by the en-/decoding experiment, the en-/decoding performance of the half of the bandwidth of the en-/decoding spectrum application is better than that of the conventional mode of center alignment. The half of the bandwidth of the en-/decoding spectrum application shall choose half of en-/decoding spectrum inclining to Level 0, thus both ensuring auto-/cross-correlation of the en-/decoding and minimizing insertion loss. The half of the bandwidth of the en-/decoding spectrum application reduces costs for light sources and improves performance of the receiver, being conducive to the practical design of the system.
Investigation of Microstructured Optical Fiber in Eight Fiber Laser
Authors: Bahloul Faouzi , Ennejah Tarek , Attia Rabah
Published: October 2011

In passively mode locked fiber laser, case of 8FL (Eight Fiber Laser), the management of length, linear and non linear parameters of the cavity plays a paramount role in the generation of stable ultra short pulses with high peak powers. In this work, we propose an 8FL consisted of MOF (Microstructured Optical Fiber). According to the various properties of the MOF, we studied the variation of the pulses peak power and width. We demonstrated that there are optimal parameters of the MOF for which the peak power is maximal and the width is minimal.
Performance Analysis of Optical CDMA Systems Utilizing Optical Encoding in Presence of Interference and Receiver Noises
Authors: Sabbagh Abbasali Ghorban , Kakhki Mohammad Molavi
Published: October 2011

In this paper, performance of incoherent and asynchronous optical CDMA (OCDMA) systems employing “optical encoding” is investigated and the results are compared with the results obtained when the encoding is performed in electrical domain. These investigations are performed for receiver structures that employ a single hard limiter (SHL), a double optical hard limiter (DHL) and also for the structures without a hard limiter (WHL). In addition, “electrical encoding” OCDMA systems using DHL in their receiver structures are investigated. In this work, conventional optical orthogonal codes are used and Gaussian approximation is assumed for the output of APD. Besides interference, other destructive effects such as APD and thermal noises are also taken into account.

It is shown that when the number of users N is equal to or greater than pulsed laser's modulation extinction ratio Me
, for all receiver structures (SHL, DHL and WHL) “optical encoding” systems are superior to their “electrical encoding” counterparts and this superiority becomes much more apparent in SHL and DHL receivers. We will also show that when N < Me
, “optical encoding” WHL systems outperform their “electrical encoding” counterparts. Our results also indicate that the performance of “optical encoding” SHL systems approaches the performance of DHL systems as the transmitted power increases.
Analysis of Impulse Responses Characteristics of an Optical Delayed Feedback Semiconductor Laser
Authors: Senlin Yan
Published: October 2011

Impulse response characteristics of a semiconductor laser with weak optical feedback (OF) is studied. Equations about the amplitude and frequency responses of the laser under the current modulation condition are deduced. We demonstrate theoretically that the equations are the function of the modulation frequency, optical feedback level and delayed time. We give the impulse response function under the jump signal modulation condition with OF and without OF, this is helpful for digital laser communications. The numerical results demonstrated that OF can make the laser obtain the enhancement of the modulation response and bandwidth and can reduce the frequency respond in the some parameters range. OF can enhance gently the relaxation oscillation of the foreland or the tail of the impulse response signal under the weak OF case while the oscillation can be enhanced sensitivity to the modulation under the larger OF case
A Modified Oxygen Consumption Test to Evaluate Gas Flux through Oxygen Barrier Cover Systems
Authors: Dagenais Anne-Marie , Mbonimpa Mamert , Bussière Bruno , Aubertin Michel
Published: October 2011

The evaluation of an oxygen barrier cover performance is an integral part of many reclamation programs that aim at limiting acid mine drainage (AMD) production from sulphide tailings. The oxygen flux through the cover to the underlying reactive tailings should then be much smaller (by a factor of 1000 or more) than the flux into exposed (uncovered) tailings. Different techniques have been developed over the years to assess this flux. Given the limitations encountered when using available approaches to measure such low oxygen flux, the authors have developed a modified testing and interpretation method based on the oxygen consumption (OC) test, which is commonly used to determine oxidation rates of uncovered tailings. The proposed modifications to the OC testing procedure are presented in this paper, together with the new interpretation method. Typical tests results obtained with the modified OC method on an existing site, reclaimed using a layered cover with capillary barrier effects (CCBE), are presented and discussed. The results demonstrate that the modified oxygen consumption (MOC) test is an effective tool to assess the performance of oxygen barrier covers used to prevent AMD.
Experimental Testing and Numerical Evaluation on Freezing for Water Hydraulics Application under Sub-Freezing Ambient Temperature Environment
Authors: Chua Patrick S. K. , Tan F. L. , Zhang J.
Published: October 2011

The work reported in this paper explores both experimental and numerical simulations on the process of freezing of pressurized fluids in stainless steel pipes for water hydraulics systems under sub-freezing ambient temperature conditions. Preliminary experimental studies were conducted to investigate the time taken for water to freeze under sub-freezing temperature conditions and to explore ways to delay and prevent the water from freezing. A test rig was designed and tested. The results of the experiments deduced that the use of insulation would delay the time for water to freeze and the use of heating pads (heaters) mounted on the insulated piping could prevent freezing altogether. Computational Fluid Dynamics (CFD) simulation software, FLUENT, was used to identify the relevant parameters, such as the thickness of the insulation, flow velocity, pipe length, and the heat flux applied along the pipe length, which could prevent the freezing of the water throughout the solution domain with proper geometries and boundary conditions.
The Effect of Nano-precipitates on Strength in a Micro-alloyed Ferritic Steel
Authors: Askari H.A. , Shen Y.F. , Wang C.M. , Sun X. , Zbib H.M.
Published: October 2011

A high strength ferritic steel with finely dispersive precipitates was investigated to reveal the fundamental strengthening mechanisms in this alloy. Using energy dispersive X-ray spectroscopy (EDXS) and transmission electron microscope (TEM), fine carbides with an average diameter of 10 nm were observed in the ferrite matrix of the 0.08%Ti steel, and some cubic M23C6 precipitates were also observed at the grain boundaries and the interior of grains. The dual precipitate structure of finely dispersive TiC precipitates in the matrix and coarse M23C6 at grain boundaries provides combined matrix and grain boundary strengthening. The resulting yield stress is two or three times higher than that of conventional Ti-bearing high strength hot-rolled sheet steels. The effect of the particle size, particle distribution and intrinsic particle strength have been investigated through dislocation dynamics (DD) simulations and the relationship for resolved shear stress for single crystal under this condition has been presented using simulation data. The results show that the finely dispersive precipitates can strengthen the material by pinning the dislocations up to a certain shear stress and retarding the recovery as well as annihilation of dislocations. The DD results also show that strengthening is not only a function of the density of the nano-scale precipitates but also of their size. This size effect is explained using a mechanistic model developed based on dislocation-particle interaction.
Tuning lattice thermal conductance in ultra-scaled hollow SiNW: Role of porosity size, density and distribution
Authors: Pau Abhijeet , Miao Kai , Luisier Mathieu , Klimeck Gerhard
Published: October 2011

Porous crystalline Si nanowires (PC-SiNW) represent an attractive solution for enhancing the thermoelectric efficiency (ZT) of SiNWs by reducing the lattice thermal conductance (κl). A modified valence force field (MVFF) phonon model along with Landauer’s approach is used to analyze the ballistic κl in PC-SiNWs. A systematic study focusing on the influence of pore size, density, and distribution on the ballistic κl of PC-SiNWs is presented. The model predicts a maximum reduction of ∼19%, ∼23% and ∼30% for 1, 2 and 3 pores, respectively with a constant removal of ∼12% of the atoms in all the cases. The model also predicts a higher reduction of the ballistic κl as the pore separation increases, in the case of 2, 3 and 4 pores, for the same percentage of atoms removed (∼12%) in all the cases. Thus, the presence of a high number of small, well-separated pores suppress κl strongly. This reduction in ballistic κl, in the coherent limit, is attributed to the reduction of the total number of phonon modes and smaller participation of phonon modes (in κl) with increasing number of pores.
Reflexões sobre a relação entre o trabalho a morte e a própria vida
Authors: Sievers Burkard
Published: October 2011

Em virtude do contínuo empenho do mundo de negócios de hoje e da maioria de nossas empresas em procurar permanente crescimento, expansão e sobrevivência, a noção da morte e da mortalidade está cada vez mais caindo no esquecimento. Este ensaio baseia-se na convicção de que qualidades humanas fundamentais como a significação, a maturidade e mesmo a sabedoria serão enfim expurgadas de nossas atividades econômicas, se as pessoas, individual ou coletivamente, não compreenderem que o trabalho que elas fazem, a vida que levam e a morte que um dia irão inevitavelmente experimentar estão todos inter-relacionados.
The Scotia Sea krill fishery and its possible impacts on dependent predators: modeling localized depletion of prey
Authors: Plagányi Éva E. , Butterworth Doug S.
Published: October 2011

The nature and impact of fishing on predators that share a fished resource is an important consideration in ecosystem‐based fisheries management. Krill (Euphausia superba) is a keystone species in the Antarctic, serving as a fundamental forage source for predators and simultaneously being subject to fishing. We developed a spatial multispecies operating model (SMOM) of krill–predator fishery dynamics to help advise on allocation of the total krill catch among 15 small‐scale management units (SSMUs) in the Scotia Sea, with a goal to reduce the potential impact of fishing on krill predators. The operating model describes the underlying population dynamics and is used in simulations to compare different management options for adjusting fishing activities (e.g., a different spatial distribution of catches). The numerous uncertainties regarding the choice of parameter values pose a major impediment to constructing reliable ecosystem models. The pragmatic solution proposed here involves the use of operating models that are composed of alternative combinations of parameters that essentially try to bound the uncertainty in, for example, the choice of survival rate estimates as well as the functional relationships between predators and prey. Despite the large uncertainties, it is possible to discriminate the ecosystem impacts of different spatial fishing allocations. The spatial structure of the model is fundamental to addressing concerns of localized depletion of prey in the vicinity of land‐based predator breeding colonies. Results of the model have been considered in recent management deliberations for spatial allocations of krill catches in the Scotia Sea and their associated impacts on dependent predator species.
Injection Fall-Off Analysis of Polymer Flooding EOR
Authors: Mahani H. , Sorop T. G. , van den Hoek P. J. , Brooks A. D. , Zwaan M.
Published: October 2011

Polymer solutions, in contrast to water, exhibit non-Newtonian rheological behavior, such as in-situ shear-thinning and shear-thickening effects, leading to a varying viscosity distribution in the reservoir. Consequently, a different pressure distribution and a rather slower pressure decline rate are exhibited during Pressure Fall-Off (PFO) test (compared to a waterflooding case). Therefore, applying a different interpretation method, compared to conventional approaches for Newtonian fluids is required.

In this paper we provide a new, simple and practical method to infer the in-situ polymer rheology and the induced fracture dimensions from PFO tests performed during polymer injection. This is based on a combination of numerical flow simulations and analytical pressure transient calculations, resulting in generic type curves that are used to compute consistency index, flow behavior index, fracture dimensions, and reservoir parameters (kh, faulting, etc.) from the measured pressure derivative curves.

The novelty of this study are the analysis of interference caused by fracture sizes on the radial stabilization of polymer, as well as the use of realistic polymer rheology, combined with an analysis method that derives polymer rheology parameters based on the pressure derivative curve.

This method can be used for interpretation of PFO tests on existing EOR polymer flooding projects, where monitoring of injection performance and of in-situ effective polymer rheology are key in the success of a project.
Incorporating PLT-Distributed Dynamic Permeability — into Reservoir Simulation Models — Improves and Accelerates the History Matching Process
Authors: Abdel-Ghani Rida , Krinis Dimitris , Camargo Jorge Nieto
Published: October 2011

Integrating dynamic data into reservoir numerical models is essential for capturing the actual dynamic flow behavior. History matching efforts could prove to be fruitless without including such data into the reservoir model. For example, open hole logs and core sampling do not provide a satisfactory characterization of fractures and super-high permeability streaks — two important flow features that can be overlooked.

Failing to incorporate these small but critical flow features can lead to inaccurate simulation models, even if the total rates at the wellhead are captured by the history match. This inaccuracy usually transpires when model results are compared to actual production profiles, and could go unnoticed until the field performance starts to deviate from predictions.

The inclusion of dynamic permeability data into the reservoir model can be performed, either during the static geological modeling, or into the dynamic simulation model, as a conditioning step. Either way, the process starts by comparing the correlation based kh values to those obtained from pressure transient testing. Various methods can be used to utilize the results of this comparison, which vary from simple zone averaging to highly detail vertical permeability profiling.

In the geocellular model, the adjusted dynamic profiles are input for the permeability population by using several methods that range from kriging to stochastic approaches. The final conditioned permeability fields can be in addition to incorporating discrete fracture models or stratiform characterization and mapping as 2D or 3D trend parameters.

This paper explains how PLT profile based distribution of the dynamic permeability resulted in a large improvement of the history match results, and just as importantly, a shorter history matching process for a giant carbonate Middle East reservoir. The paper also shows alternative approaches for incorporating the dynamic permeability into the simulation model, but which did not produce the same desired results.
Slippage Effect and Quasi Starting Pressure in Low Permeability Water-Bearing Gas Reservoirs
Authors: Liu Xiaojuan , Yan Jian , Liu Yi
Published: October 2011

Lab tests were carried out to study the gas slippage and quasi starting pressure in water-bearing gas reservoirs of low permeability. The permeability of the testing cores is mainly lower than 1 mD. The testing results indicate that: for similar water saturation, the lower the permeability is, the more serious the gas slippage is. For similar permeability, with the increasing of water saturation, the gas slippage effect increases first and then decreases. The turning point is called critical water saturation (Sw)c1. The relationship between the critical water saturation and the core coefficient is binomial, where the core coefficient is the ratio between permeability and porosity. By curve fitting, it was found that, when the water saturation is lower than a critical value, gas slip factor is a logarithmic function of the ratio of core coefficient and water saturation; when water saturation is higher than the critical value, the gas slip factor is a logarithmic function of the multiplication of core coefficient and water saturation. The quasi starting pressure gradient may exist when the gas flow in porous media that contains water. The reason is that the increase of capillary resistance is larger than gas slippage as the water saturation rises. In further, it was concluded that there is another critical water saturation (Sw)c2. When the water saturation is larger than the critical value (Sw)c2, the quasi starting pressure gradient exists. The relationship between the quasi starting pressure gradient and the ratio of core coefficient and water saturation is a power function. Further more, the relationship between the critical water saturation and absolute permeability is also a power function.
Seismic-to-Simulation for Unconventional Reservoir Development
Authors: Cipolla C. L. , Fitzpatrick T. , Williams M. J. , Ganguly U. K.
Published: October 2011

The completion strategy and hydraulic fracture stimulation are the keys to economic success in unconventional reservoirs. Therefore, reservoir engineering workflows in unconventional reservoirs need to focus on completion and stimulation optimization as much as they do well placement and spacing. This well-level focus requires the integration of hydraulic fracture modeling software and the ability to utilize measurements specific to unconventional reservoirs. This paper details a comprehensive integration of software, data, and specialized measurements specific to unconventional reservoirs that allows efficient full-cycle seismic-to-simulation evaluations.

It is very important to properly model hydraulic fracture propagation and hydrocarbon production mechanisms in unconventional reservoirs, a significant departure from conventional reservoir simulation workflows. Seismic-to-simulation workflows in unconventional reservoirs require hydraulic fracture models that properly simulate complex fracture propagation which is common in many unconventional reservoirs, algorithms to automatically develop discrete reservoir simulation grids to rigorously model the hydrocarbon production from complex hydraulic fractures, and the ability to efficiently integrate microseismic measurements with geological and geophysical data. The introduction of complex hydraulic fracture propagation models now allows these work-flows to be implemented.

This paper documents an efficient, yet rigorous, integration of geological and geophysical data with complex fracture models, single-well completion and stimulation focused reservoir simulation, and microseismic measurements. The implementation of a common software platform and the development of specialized gridding algorithms allow complex hydraulic fracture models to be calibrated using microseismic measurements in the context of local geology and structure. The complex hydraulic fracture geometry, including the distribution of proppant, is automatically gridded to a common Earth Model for single-well reservoir simulation. The software platform, newly developed complex hydraulic fracture models, and automated gridding algorithms are illustrated in a case history from the Barnett Shale unconventional gas play.
Horizontal Well Modeling in Case of Highly Heterogeneous Anisotropic Reservoir
Authors: Tsyganova E. F.
Published: October 2011

Horizontal wells application in heterogeneous reservoirs is challenging as assumes high expenditures in conditions of problems with such wells modeling. The model matched to history data can show inaccuracy in horizontal wells performance forecast. In this paper the issue is investigated with using of integrated approach.

Uncertainties related to reservoir complexity are considered as possible sources of erroneous prediction. Reservoir study coupled with the review of analytical solutions is conducted to identify the uncertain parameters influencing horizontal well performance. Their ranges of variation obtained from research data are included into qualitative analysis of uncertainties impact. It is performed on the model with estimation of oil production as a main decision criterion. All the uncertainties are incorporated into simulation process with using of Monte Carlo technique and automatic history matching. Non-unique nature of the model is shown and the significance of performing multivariant prediction for horizontal wells is proved.

As a result the modeling procedure with uncertainties inclusion is proposed and methods of uncertainties reduction are recommended in order to increase model reliability. This will allow uncertainties management and more founded decision making.
Assessing Structured Uncertainty in a Mature Fractured Reservoir, Using Combination of Response Surface Method and Reservoir Simulation
Authors: Khosravi Maryam , Fatemi Shohreh , Rostami Behzad
Published: October 2011

In recent years the oil industry has given great importance to reservoir uncertainty analysis, because, it would control the financial uncertainties; however, the development of a method that could model it based on pure reservoir simulation would be complex while the influence of the parameters on reservoir performance is non linear. Therefore, different approaches such as experimental design, response surface methodology and Monte Carlo simulation have been combined with reservoir modeling to simplify addressing the uncertainties.

In this work, dynamic model of a fractured mature reservoir has been constructed from a static primary structure. But, this process is totally crucial and challenging, because of limited knowledge of fracture network parameters and characteristic, that could be source of uncertainty in reservoir performance. Therefore, response surface method is used to realize the most influential parameters on pressure drop and recovery factor changes, regarding their practical levels of uncertainties during the development of fractured reservoir model. The present approach is performed to magnify the significant parameters and developing compatible and more realistic proxy equation for forecasting oil recovery from a typical low permeable fractured reservoir. The proxy model allows Monte-Carlo analysis to determine sensitivities and the quantification of the impact of uncertainty on production forecasts. Furthermore, it helps making reliable decision during the reservoir development.

Results indicate that the oil recovery is more sensitive to aquifer strength, fracture permeability and block height. However the interaction between other parameters such as matrix size, fracture permeability and aquifer volume, showed a degree of importance during this analysis. Monte-Carlo analysis forecasts wide range of oil recovery for this field development. The result indicates that the range of fracture permeability and aquifer characteristic should be attained carefully to reduce degree of uncertainties in field development strategies.
Reservoir Rock Typing of a Giant Carbonate Field
Authors: Al Ameri Mohamed B. , Shebl Hesham
Published: October 2011

Reservoir Rock Types of Kharaib reservoirs have been defined as an interval of rock within which the geological and petrophysical properties that effect fluid flow are consistent and predictable. Lithofacies classifications are a purely geological grouping of reservoir rocks, which have similar lithology, texture, grain size, sorting etc. Each lithofacies indicates a certain depositional environment with a distribution trend and dimension. Petrophysical groups are classified by Porosity, Permeability, Capillary Pressure and Pore throat size distribution.

A Rock Type combines both these classifications by linking petrophysical properties and lithofacies as part of the reservoir rock type definition. It has been previously shown that the static rock types are not always representative of multi-phase flow behavior in the reservoir. In this paper, we will present evolution of the rock type scheme within ZADCO. We discuss criteria used to define reservoir rock types in the current unified scheme. The objective of the proposed rock type scheme is to address shortcomings identified with the previous one in use and is based on the following criteria: a) each Rock Type can be characterized by similar depositional environment and diagenetic process; b) Porosity/Permeability overlap is minimal between different rock types; c) each rock type has a typical and unique set of Pore Throat Size Distribution; and d) each rock type has similar set of Capillary Pressure/Relative Permeability curves at a given wettability.

The recognized Reservoir Rock Types have been assigned to reservoir layers were built within a framework based on sequence stratigraphic concepts to ensure that the spatial 3D distribution of each rock types is predictable within a well-defined geological framework and finally to be used in history matching simulation models.
Assessing the Impact of Fault Connectivity Uncertainty in Reservoir Studies using Explicit Discretization
Authors: Cherpeau Nicolas , Caumon Guillaume , Caers Jef , Lévy Bruno
Published: October 2011

Reservoir production curves provide significant information about reservoir compartmentalization and connectivity, but are most often used at late stages of reservoir modeling workflows, leading to possible inconsistencies between static and dynamic reservoir models. In this paper, we propose to use this information during structural modeling to reduce fault-related uncertainties induced by subsurface imaging and interpretation ambiguities.

We first generate stochastic fault networks from prior information about faults hierarchy, size, orientation, roughness and localization. Then, the results are discretized into a set of nodes and pipes, called a pipe network, which represents the control volumes connectivity graph. This discretization data structure accurately represents fault surfaces and fault connections while limiting the number of nodes to represent the domain of interest as a connectivity graph that can be fed to a flow simulator. In a third step, we select models that best match the production curves.

The proposed method is flexible enough to assess high uncertainties that may require to add or remove faults, or to perturb the fault connectivity, without need for simplification of the fault network into a corner-point reservoir grid. The method is applied to a synthetic example of high uncertainties relative to a poorly imaged 3D fault zone.
A Team-Based Approach to History Matching a Giant Carbonate Reservoir Using Sector Models with a Domain Decomposition Workflow
Authors: Brantferger M. , Al-Jenaibi H. M. , Patel H. , Al Harbi A. S. , Kompanik G. S. , Mubarak M.
Published: October 2011

Numerical simulation models have been used to optimize oil recovery since the 1960's. Typical steps to create a simulation model include 1) building a static model based on all available geological and petrophysical data; 2) history matching the static model to tune it to the available production and measured data; and 3) using the conditioned model to design drill-wells, predict pressure evolution, and forecast flow streams for business decisions. Today it is generally accepted that the best models result from using interdisciplinary teams to ensure geologic consistency is maintained during the history matching modifications – e.g. Sibley (1997), Landis (2005).

We discuss herein a unique approach to efficiently manage and expedite the history matching of a giant carbonate reservoir using a team of simulation engineers. The workflow was developed based on domain decomposition principles to divide the problem into manageable sector models with coordinated updates between the sector and full field model to obtain the full-field history match. With this approach, dynamic history matching is divided among many simulation engineers in a way that maintains the base geologic model, vets regional modifications, and transmits local lessons to the full-field model.

The workflow relies on fast extraction, creation, and management of sector models (or subdomains) from the full field. Each sector is linked to the full field by incorporating flux boundary conditions obtained from either a larger sector model or the full-field model. The proposed approach allows for the acceleration of the history match by effectively dividing the work among a team of simulation engineers. The "sector" approach of making smaller models from one large model speeds up the model build and run times making it convenient to have the multiple iterations necessary to achieve a satisfactory history match in a complex, high-contrast flow strata geologic environment.

The goal of the work was to reduce the time to achieve the history match to one year, as opposed to the previous experience requiring several years for similarly sized models. Some critical advantages and lessons from the workflow will be discussed through its application using actual history matching examples from a giant offshore, Middle Eastern, carbonate reservoir having over four decades of production history.
PIV Investigation of Liquid Flow Field in Off-Centered Shaft Stirred Tanks with Floating Particles
Authors: Atibeni Rajab Abd alsalam , Gao Zhengming , Bao Yuyun
Published: October 2011

The local behavior of continuous phase in a stirred tank with floating particles was investigated by using PIV technique. The effect of solid concentration and off-centered shaft position on the fluid field were studied. Experimental measurements were carried out in a fully baffled cylindrical vessel equipped with a flat bottom and an up-pumping 4-Wide-blade Hydrofoil impeller (WHU). The diameter of the vessel, the diameter of the impeller, and the vertical clearance of the bottom were 0.192 m, 0.075 m, and 0.064 m, respectively. The liquid phase was water, and low density polyethylene flat cylindrical particles were used as the floating particles at different concentrations (0.0, 0.6, 0.8, and 1.0 vol.%) and different shaft positions (0.0, 0.0096, 0.0192, and 0.0288 m away from the center of the tank, corresponding to the eccentricities of 0%, 5%, 10%, and 15%, respectively). PIV measurements showed that the velocity increases by approximately 50% in the tank with the most eccentric shaft. Axial and radial mean velocities for the carrier liquid phase were also measured by using fluorescent particles. Results indicated that as the increase of floating particle concentration, the velocity decreases by about 16% in the main flow direction. In addition, the flow behavior is not affected by the presence of floating particles, and the circulation pattern is similar in both the absence and the presence of floating particles.
Polyphenol content and antioxidant activity of sour cherries from Serbia
Authors: Mitic Milan , Obradovic Mirjana , Kostic Danijela , Micic Ruzica , Pecev Emilija
Published: October 2011

The aim of this study is to evaluate the content of phenolics: the total
phenols (TP), flavonoids (TF), anthocyanins (TA), as well as the total
antioxidant capacity (TAC) in three sour cherry cultivars (Prunus cerasus L.)
introduced to the southeast Serbia climate conditions. Among the researched
sour cherries, ?Oblacinska? cultivar contained the highest amounts of all
groups of phenolics, followed by ?Cigancica? > ?Marela?. A significant
difference were observed in the phenolic content among different cultivars
and growing seasons (p<0.05), and the phenolic compounds were significantly
higher in the growing season 2009. The examined cultivars possess a high
antioxidant capacity, and all phenolics of highy correlation with TAC. The
following compounds were identified and quantified using HPLC-DAD: 4
anthocyanins, the most abundant of which was cyaniding-3-glucoside in
?Marela? and ?Oblacinska?, and cyanidin-3-glucosylrutinoside in ?Cigancica?,
and 4 hydroxycinnamic acids, the most abundant of which was neochlorogenic
acid in all sour cherry cultivars. The growing and ripening process on the
tree of sour cherry cv. Oblacinska was evaluated, also. The results showed
significant increases in total phenols during the ripening, the total
anthocyanins and total antioxidant capacity and 4 quantified anthocyanins,
however the neochlorogenic acid decreased during the ripening. The study
indicated that the growing and climate conditions in southeast Serbia are
convenient for introducing sour cherry cultivars.
Effects of microwave pretreatment on the energy and exergy utilization in thin-layer drying of sour pomegranate arils
Authors: Motevali Ali , Minaei Saeid
Published: October 2011

Energy and exergy analyses may be considered as important tools for design,
analysis and optimization of thermal systems. This paper reports on energy
and exergy analyses of thin-layer drying of sour pomegranate arils with
microwave pretreatment. There were two microwave pretreatments (100W for 20
min and 200 W for 10 min) along with a control treatment (convection drying
with no microwave pretreatment). Experiments were carried out at three air
temperatures (50, 60 and 70?C) and three air velocities (0.5, 1 and 1.5 m/s).
Results showed that energy utilization and energy utilization ratio increased
with time, while exergy efficiency decreased. Energy utilization and drying
time decreased considerably with microwave pretreatment of pomegranate arils.
The minimum values of exergy loss and exergy efficiency were associated with
the 200W microwave pretreatment, while they were maximum for control
treatment.
Calling It Mammon
Authors: Murphy Liam D.
Published: October 2011

Competitive funding by the European Union for community projects in Northern Ireland operates according to a political logic in which some groups and projects (deemed progressive, modern and generally secular) are prioritised, while others (discursively positioned as anachronistic, traditional and religious) are precluded. In this process, EU processes of statecraft seek to instrumentalise grassroots organisations as means to the many ends of a disenchanted, modern EU federation. In turn, overtly religious groups (among them churches, parachurches, and confraternities of various kinds) adapt to these conditions by instrumentalising EU processes and goals to the general end of securing a future place for religiosity in the 'new' Northern Ireland. This paper discusses the intersection of religious objectives and ideologies with that of European modernism in the context of two organisations: the Orange Order and the Divine Fellowship Congregation (DFC). Speci fically, I argue that both associations have developed distinctive forms of practice (the 'Orangefest' and 'Utopia' projects, respectively) that re-conceive what is possible for modern EU-funded initiatives. This adaptation has implications for both sets of institutions, in that each is transformed through articulation with the other.
Books Received
Authors: Craith Máiréad Nic
Published: October 2011

Books Received for Review
Cloud Processing of Gases and Aerosols in Air Quality Modeling
Authors: Gong Wanmin , Stroud Craig , Zhang Leiming
Published: October 2011

The representations of cloud processing of gases and aerosols in some of the current state-of-the-art regional air quality models in North America and Europe are reviewed. Key processes reviewed include aerosol activation (or nucleation scavenging of aerosols), aqueous-phase chemistry, and wet deposition/removal of atmospheric tracers. It was found that models vary considerably in the parameterizations or algorithms used in representing these processes. As an emerging area of research, the current understanding of the uptake of water soluble organics by cloud droplets and the potential aqueous-phase reaction pathways leading to the atmospheric secondary organic aerosol (SOA) formation is also reviewed. Sensitivity tests using the AURAMS model have been conducted in order to assess the impact on modeled regional particulate matter (PM) from: (1) the different aerosol activation schemes, (2) the different below-cloud particle scavenging algorithms, and (3) the inclusion of cloud processing of water soluble organics as a potential pathway for the formation of atmospheric SOA. It was found that the modeled droplet number concentrations and ambient PM size distributions were strongly affected by the use of different aerosol activation schemes. The impact on the modeled average ambient PM mass concentration was found to be limited in terms of averaged PM2.5 concentration (~a few percents) but more significant in terms of PM1.0 (up to 10 percents). The modeled ambient PM was found to be moderately sensitive to the below-cloud particle scavenging algorithms, with relative differences up to 10% and 20% in terms of PM2.5 and PM10, respectively, when using the two different algorithms for the scavenging coefficient (Λ) corresponding to the lower and upper bounds in the parameterization for Λ. The model simulation with the additional cloud uptake and processing of water-soluble organic gases was shown to improve the evaluation statistics for modeled PM2.5 OA compared to the IMPROVE network data, and it was demonstrated that the cloud processing of water-soluble organics can indeed be an important mechanism in addition to the traditional secondary organic gas uptake to the particle organic phase.
Expression of Elongation Factor (EF)-Tu Is Correlated with Prognosis of Gastric Adenocarcinomas
Authors: Xu Chaoyang , Wang Jianjun , Li Jiajia , Fang Rengui
Published: October 2011

Altered expressions of mitochondria elongation factor Tu (EF-Tu) have been observed in certain types of cancers, including gastric cancer cell lines, but the impact of the alterations in gastric adenocarcinoma remains unclear. The purpose of this study was to investigate the expression of EF-Tu in gastric adenocarcinoma and to assess its clinical significance. A total of 104 paired resected gastric adenocarcinoma and corresponding normal specimens were collected in this study. EF-Tu expression was assessed by immunohistochemical staining. The correlation of EF-Tu expression and patients’ clinicopathological parameters was statically evaluated and the prognostic significance of EF-Tu expression was assessed by univariate and multivariate analyses. Forty-nine out of 104 (47.1%) gastric adenocarcinoma specimens showed high expression of EF-Tu, while the remaining 55 specimens showed weak or negative expression of EF-Tu. In contrast, EF-Tu high expression was detected in 62.5% (65 of 104) normal tissues. Down-regulation of EF-Tu was associated with serosal invasion (P = 0.042) and node involvement (P = 0.005), and down-regulation of EF-Tu was correlated with poor overall survival (P = 0.020). In curative resection (R0) patients, there were also significant differences (P = 0.043). In the multivariate analysis, the EF-Tu expression remained a significant independent prognostic factor (P = 0.038). Our results indicate that EF-Tu is expressed in both gastric adenocarcinoma and corresponding normal tissues. Down-regulation of EF-Tu expression is associated with advanced disease stage and EF-Tu expression maybe served as an independent prognostic factor.