bluuebunny/crossref_metadata_2025 huggingface dataset:
Stochastic Collocation Methods for Efficient and Accurate Quantification of Uncertainty in Multiphase Reservoir Simulations
Authors: Li Heng , Chang Haibin , Zhang Dongxiao
Published: February 2009

Reservoir simulation is subject to uncertainties, which may stem from inaccurate and imprecise measurements or inadequate characterization of spatially or temporally varying medium properties. Such uncertainties render the model parameters random and the equations describing flow and transport in the media stochastic. There exist several stochastic approaches for quantifying uncertainties, which, however, are either incompatible with existing deterministic simulators or are too demanding computationally. In this study, an alternative approach is proposed that is both accurate and efficient. In this approach, the uncertainty quantities such as permeability and porosity fields are represented by the Karhunen-Loeve expansions while the fluid saturations and reservoir production quantities are expressed by the polynomial chaos or Lagrange polynomial expansions. Two collocation-based methods, i.e. probabilistic collocation method (PCM) and Smolyak method are used to determine the coefficients of the polynomials expansions by solving for the fluid saturations and pressures at different collocation points via the original partial differential equations. This approach is non-intrusive in that it results in independent deterministic differential equations, which similar to the Monte Carlo method, can be implemented with existing codes or simulators. However, the required number of simulations in PCM or Smolyak method is much smaller than that in the Monte Carlo method. The approach is demonstrated with three-phase flow problems in heterogeneous reservoirs using Eclipse. The accuracy, efficiency, and compatibility of this approach are compared against Monte Carlo simulations. This study reveals that while their computational efforts are greatly reduced compared to Monte Carlo method, the stochastic collocation methods are able to accurately estimate the statistical moments and probability density functions of the fluid saturations, pressures, and production quantities of interest.
Results of the Brugge Benchmark Study for Flooding Optimization and History Matching
Authors: Peters E. , Arts R. J. , Brouwer G. K. , Geel C. K.
Published: February 2009

In preparation for the SPE-ATW held in Brugge in June 2008 a unique benchmark project to test the use of flooding optimization and history-matching methods was organized in the form of an interactive competition during the months preceding the ATW. In total nine different groups participated and presented their results during the workshop.

Prior to the Brugge workshop, early 2008, a 3D synthetic dataset was made available to the participants by TNO. The dataset consisted of 104 upscaled realizations of a 3D geological model, well-log data from wells with fixed positions, the first 10 years of the production history of the field (including measurement errors), inverted time-lapse seismic data in terms of (uncertain) pressures and saturations, and economic parameters for oil and water (price and discount rate).

Participants were asked to provide a history match (either a single matched "best" model or a matched ensemble) based on the available data, and an optimal production strategy (without infill drilling) for the next period (10-20 years). Their strategy was tested on the "real field" to obtain additional production data over the 10-year period. Using these production data, the participants updated their reservoir model and revised their optimal production strategy for the final period of production (20-30 year).

The final objective of the exercise was to optimize, within a time constraint, the NPV of a waterflooded oilfield having smart wells that can be controlled by an inflow control valve per completed layer. The results of the nine participants are compared to an optimization of the "real field" as performed by TNO.

This paper gives an overview of the results obtained from this benchmark study. After the Brugge workshop the participants that were not able to finalize the exercise in time were given an additional two months time. The results of this additional exercise are reported in this paper as well.
Accurate Inflow Profile Prediction of Horizontal Wells through Coupling of a Reservoir and a Wellbore Simulator
Authors: Kabir Akim , Sanchez Gerardo
Published: February 2009

Predicting accurate inflow pressure and flow profile of horizontal laterals is one of the biggest impediments in achieving their optimum performance. Reservoir simulators are capable of simulating flow in the reservoir up to the fluid entry points in the well reasonably well. Wellbore simulators can simulate flow from the fluid entry points up to the surface delivery system. The integrated system can be simulated numerical reservoir simulators adequately assuming a single point fluid entry to the well. However, accurate foot by foot prediction of pressure and flow profile at the reservoir/well interface of long horizontal wells is a challenge. Some simulators attempt to simulate this detailed inflow profile using some simplified approach. A few semi-analytical modeling approach is also available in the literature. They use average parameter values in their calculation. These simplifying assumptions result in less than accurate inflow profile prediction to the extent that they are inadequate for some design optimization studies.

In this paper we describe coupling of a 3-D numerical reservoir simulator with a wellbore simulator in a simple manner which is capable of predicting a detailed inflow profile along long horizontal wells. Flow and pressure along the laterals are iterated between the simulators at each point of interface until they converge. This convergence is repeated at desired time intervals ultimately resulting in a fully converged integrated reservoir-wellbore simulation with the detailed and accurate inflow profile. The algorithm was initially tested manually and later automated. Results of the work is presented along with an application (designing Inflow Control Devices) aimed at achieving uniform flow profile along horizontal laterals. This is a powerful capability which will enable us optimize horizontal completions to the extent which was not possible before.
Closed Loop Reservoir Management Using the Ensemble Kalman Filter and Sequential Quadratic Programming
Authors: Lorentzen Rolf J. , Shafieirad Ali , Naevdal Geir
Published: February 2009

As part of the SPE-ATW"Closed-loop reservoir management" held in Bruges, June 2008, a synthetic data set was made available to the participants. This paper describes our workflow and results for closed-loop reservoir management using this synthetic model. The closed-loop exercise is divided into two cycles, each consisting of data assimilation and production optimization. The data assimilation is done using the ensemble Kalman filter, and the optimization is done using sequential quadratic programming after a reformulation of the problem to reduce the number of variables.

The methodology performs well on the case considered here, and high NPV values are obtained. In particular we have proposed a new strategy for production optimization that makes a large scale optimization problem feasible through a proper reduction of control variables based on analysis of the properties of the field and application of a state of the art optimization method.
An EOS-Based Compositional Thermal Reservoir Simulator
Authors: Varavei Abdoljalil , Sepehrnoori Kamy
Published: February 2009

In the past thirty years, the development of compositional reservoir simulators using various equations of state (EOS) has been addressed in the SPE literature. However, the development of compositional thermal simulators in conjunction with EOS formulation has been ignored, in particular. Therefore, a fully implicit, parallel, compositional EOS-based simulator has been developed. In this model, an equation of state is used for equilibrium calculations among all phases (oil, gas, and aqueous). Also, the physical properties are calculated based on an EOS, hence obviating the need for using steam tables for calculation of water/steam properties. The governing equations for the model comprise fugacity equations between the three phases, material balance, pore volume constraint and energy equations. The governing partial differential equations are solved using finite difference or finite volume approximations. In the steam injection process, the solubility of oil in water-rich phase and the solubility of water in oil phase can be high. This model takes into account the solubility of water in oil phase and the solubility of hydrocarbon components in water-rich phase, using three-phase flash calculations.

This simulator can be used in various thermal flooding processes (i.e. hot water or steam injections). Since the simulator was implemented for parallel computers, it is capable of solving large-scale thermal flooding problems. The simulator is successfully validated using analytical solutions. Also, simulations are carried out to compare this model with commercial simulators.

The use of an EOS for calculation of various properties for each phase automatically satisfies the thermodynamic consistency requirements. On the other hand, using the K-value approach, which is not thermodynamically robust, may lead to results that are thermodynamically inconsistent. This simulator accurately tracks all components and mass transfer between phases using an EOS; hence, it will produce thermodynamically consistent results and project accurate prediction of thermal recovery processes.
Dynamic Upscaling of Multiphase Flow in Porous Media via Adaptive Reconstruction of Fine Scale Variables
Authors: Lee S. H. , Wang X. , Zhou H. , Tchelepi H. A.
Published: February 2009

We propose an upscaling method that is based on dynamic simulation of a given model in which the accuracy of the upscaled model is continuously monitored via indirect error-measures. If the indirect error measures are bigger than a specified tolerance, the upscaled model is dynamically updated with approximate fine scale information that is reconstructed by a multi-scale finite volume method (Jenny et al., JCP 217: 627–641, 2006). Upscaling of multi-phase flow entails a detailed flow information in the underlying fine scale. We apply adaptive prolongation and restriction operators for flow and transport equations in constructing an approximate fine scale solution. This new method eliminates inaccuracy associated with the traditional upscaling method which relies on prescribed inaccurate boundary conditions in computing upscaled variables. The new upscaling algorithm is validated for two-phase, incompressible flow in two dimensional porous media with heterogeneous permeabilities. It is demonstrated that the dynamically upscaled model achieves high numerical efficiency than the fine-scale models and also provides an excellent agreement with the reference solution computed from fine-scale simulation.
Higher Order Multidimensional Wave Oriented Upwind Schemes for Flow in Porous Media on Unstructured Grids
Authors: Lamine Sadok , Edwards Michael G.
Published: February 2009

Standard reservoir simulation schemes employ single-point upstream weighting for convective flux approximation. These schemes introduce both coordinate-line numerical diffusion and cross-wind diffusion into the solution that is grid and geometry dependent.

New locally conservative higher-order multi-dimensional upwind schemes that minimize both directional and cross-wind diffusion are presented for convective flow approximation. The new schemes are comprised of two steps; (a) Higher-order approximation that corrects the directional diffusion of the approximation, (b) Truly multi-dimensional upwind approximation, which involves flux approximation using upwind information obtained by upstream tracing along wave-vector paths where wave information travels in multiple dimensions. This approximation reduces cross-wind diffusion. Conditions on tracing direction and CFL number lead to a local maximum principle that ensures stable solutions free of spurious oscillations. The schemes are coupled with full-tensor Darcy flux approximations.

Benefits of the resulting schemes are demonstrated for classical convective test cases in reservoir simulation including cases with full tensor permeability fields, where the methods prove to be particularly effective. The test cases involve a range of unstructured grids with variations in orientation and permeability that lead to flow fields that are poorly resolved by standard simulation methods. The higher dimensional formulations are shown to effectively reduce numerical cross-wind diffusion effects, leading to improved resolution of concentration and saturation fronts.
Convergence of MPFA on Hexahedra
Authors: Matringe S. F. , Juanes R. , Tchelepi H. A.
Published: February 2009

We present a new mixed finite element for hexahedra, conforming in H(div). The new velocity space is similar in construction to that of BDDF of order one, but has four degrees of freedom per face instead of three. The natural degrees of freedom defining the velocity field are the components of the velocity normal to each face at the vertices of that face. We apply the new element to the numerical solution of second order elliptic equations with full tensor coefficients. We prove convergence of the method and provide optimal error estimates for the scalar and vector fields. We use an appropriate numerical quadrature to localize the mixed finite element method into a cell-centered finite difference method. For diagonal tensor coefficients, we recover the usual 7-point stencil. For full tensors, the method leads to a 27-point stencil of multipoint flux approximation (MPFA) methods—specifically the well-known O-method. Our construction allows us to prove, for the first time, convergence of the MFPA O-method on three-dimensional rectangular hexahedra. The results of the error analysis are confirmed by numerical experiments. Although our analysis is restricted to rectangular parallelepipeds, our implementation allows for distorted elements and unstructured grids.
Linear Solver Performance Optimization in Reservoir Simulation Studies
Authors: Mishev Ilya , Beckner Bret , Fedorova Nelli , Terekhov Serge
Published: February 2009

The numerical simulation of oil and gas reservoirs requires the solution of many large linear systems at each time step. The performance of the linear solver depends strongly on the proper choice of parameters for the iterative method and preconditioner. We describe a suite of adaptive algorithms to optimize solver performance that systematically adjusts solver parameters during a simulation. These algorithms are implemented into a software system called Intelligent Performance Assistant (IPA) that has been successfully integrated into ExxonMobil's proprietary reservoir simulator, EMpower™.

The IPA system consists of three parts: IPALight, IPADataBase, and IPAFactory. IPALight implements an online adaptive control mechanism to provide parameters for each linear solver in a simulation. IPALight selects an initial parameter set from IPADataBase of solved cases and manipulates parameters based on the performance of the solver (e.g., solver CPU time, number of iterations, memory usage) using multi-objective optimization algorithms. This strategy improves the CPU time of the solver (frequently by 30% or more) for realistic simulation models when compared to default solver settings.

Runtime solver performance statistics gathered by IPALight for different parameter combinations are stored in IPADataBase. This data can be used by the IPA offline data analysis system, IPAFactory, to exclude all combinations that generated unsatisfactory solver performance including CPU time, memory costs and/or convergence rate. In addition, IPAFactory is used to generate good initial sets of solver parameter combinations that can be used by IPALight for similar cases. This gives improved robustness of reservoir simulations and an additional 10-20% CPU time savings.
First Application of Concentric Nitrogen Injection Technique for a Managed Pressure Drilling Depleted Well in Southern Mexico
Authors: Urbieta A. , Tellez C. Perez , Lupo C. , Castellanos J. M. , Ramirez O. , Puerto G. , Bedoya J.
Published: February 2009

Samaria field in southern Mexico is one of the oldest light oil producers. Reservoir pressures can be classified as highly depleted in cretaceous, the use of nitrogen injection thru the drill pipe to lighten the mud column is a common practice to reach low equivalent circulating densities and avoid massive loss circulation and related hole cleaning problems. Large amounts of nitrogen injection rates are also a common scenario in this specific field many times reaching the technical limit of a multiphase Managed Pressure Drilling application avoiding the friction dominated side of pressure curves. Natural tendency to achieve more production is to drill horizontal wells as demonstrated by the production results of a number of attempts made in the past. However, the presence of high N2 injection rates thru the drill pipe represents a serious challenge for measuring and logging while drilling pulse type downhole tools frustrating the possibility of achieving a full directional control in the reservoir section. Dowhole temperatures are also higher than conventional drilling because of the presence of high gas vs liquid ratios, reaching very fast the technology limits. This document presents the engineering process, planning and design for the drilling with concentric casing nitrogen injection technique in a horizontal well with directional control in real time, into a low pressure reservoir. The technique allowed building up and correcting the well trajectory successfully reaching the proposed targets. (Horizontal length, Drain Area) The steady stable and transient simulations to validate stabilization are also presented along with the final results in terms of production and skin damage.
Evaluation of Well Productivity Loss due to Formation Damage Caused by Spontaneous Imbibition in Underbalanced Drilling
Authors: Khansari Alireza Naziri
Published: February 2009

Under balanced drilling (UBD) is a drilling operation in which effective bottom hole pressure caused by circulation of drilling fluid is taken under near well bore formation pressure. As a result influx of water from aqueous drilling fluid into the formation is prevented. Even though UBD is expected to prevent formation damage and improve well productivity, in some low permeability cases with high capillary pressure counter-current imbibition occurs and reduces well productivity specially for open hole completed horizontal wells. In this paper a new approach to model possible spontaneous imbibition during UBD are presented and the related formation damage is taken into account. The impact of this type of formation damage on well productivity is simulated using a commercial reservoir simulator coupled with a developed toolbox. The simulation result is compared against the absence of spontaneous imbibition in reservoir models with lower capillary pressure. Sensitivity analysis shows that formation damage caused by UBD depends on various reservoir parameters and drilling conditions. Different cases of ROP, hydrostatic pressure of drilling fluid, initial water saturation, and porosity in low permeability reservoir caused by capillary pressure are considered. Surface tension can vary with pressure and temperature; however, it is assumed as negligible in this study. Results show this formation damage should be considered during economics and feasibility studies.
Multiscale Model of the GaAs MOVPE Process for the Fast Numerical Simulation
Authors: Im Ik-Tae , Sugiyama Masakazu , Shimogaki Yukihiro , Nakano Yoshyaki
Published: February 2009

As a successive work to clarify the film growth kinetics of GaAs, a new lumped model for computer simulation of film growth during MOCVD process is proposed. The film growth process in a horizontal reactor using trimethylgallium (TMGa) and tertiarybutylarsine (TBAs) is considered. Analyzing methodologies at two different scales have been used to revise our previous simulation model. One is the micro-scale analysis using a selective-area growth method and the other is the reactor-scale macro analysis using numerical simulation. Species concentration profiles are obtained from the macro-scale computational fluid dynamics study incorporated with chemical reactions. Surface reaction rate constants are extracted from the selective-area growth experiments. From the multi-scale analysis that combined the two-scale analyses, surface formation from the source gas, TMGa, is included to the previous model. The kinetic data for the surface reaction of TMGa are deduced from the quantitative analysis for the species concentrations from both of the analyses. Simulation results using the new model show that monomethylgallium is the major source of film deposition, but deposition from TMGa is important in the upstream region of the reactor.
The Impact of Auditor-Related Tax Services on Corporate Debt Pricing
Authors: Fortin Steve , Pittman Jeffrey A.
Published: February 2009

ABSTRACT: We examine the link between auditor-related tax services and corporate debt pricing. After controlling for security-level and other firm-level determinants, we provide strong, robust evidence that bondholders reward public firms that pay proportionately more tax fees to their auditor with lower yield spreads. Our results include that the influence of auditor-related tax services on lowering borrowing costs is stronger for issues made by firms suffering worse information asymmetry. This research, which helps to resolve whether audit quality hinges on the relative amount of tax services, may have important policy implications given that regulators continue to debate whether to impose further restrictions on the tax services that auditors can provide to their clients. Altogether, our evidence implies that the benefit of tax services in improving auditor knowledge—stemming from public accounting firms learning more about their clients over successive engagements—outweighs any concurrent sacrifice in auditor independence in shaping debt market perceptions.
Genetic Deficiency of Itgb2 or ItgaL Prevents Autoimmune Diabetes Through Distinctly Different Mechanisms in NOD/LtJ Mice
Authors: Glawe John D. , Patrick D. Ross , Huang Meng , Sharp Christopher D. , Barlow Shayne C. , Kevil Christopher G.
Published: February 2009

OBJECTIVE

Insulitis is an important pathological feature of autoimmune diabetes; however, mechanisms governing the recruitment of diabetogenic T-cells into pancreatic islets are poorly understood. Here, we determined the importance of leukocyte integrins β2(Itgb2) and αL (ItgaL) in developing insulitis and frank diabetes.

RESEARCH DESIGN AND METHODS

Gene-targeted mutations of either Itgb2 or ItgaL were established on the NOD/LtJ mouse strain. Experiments were performed to measure insulitis and diabetes development. Studies were also performed measuring mutant T-cell adhesion to islet microvascular endothelial cells under hydrodynamic flow conditions. T-cell adhesion molecule profiles and adoptive transfer studies were also performed.

RESULTS

Genetic deficiency of either Itgb2 or ItgaL completely prevented the development of hyperglycemia and frank diabetes in NOD mice. Loss of Itgb2 or ItgaL prevented insulitis with Itgb2 deficiency conferring complete protection. In vitro hydrodynamic flow adhesion studies also showed that loss of Itgb2 completely abrogated T-cell adhesion. However, ItgaL deficiency did not alter NOD T-cell adhesion to or transmigration across islet endothelial cells. Adoptive transfer of ItgaL-deficient splenocytes into NOD/Rag-1 mice did not result in development of diabetes, suggesting a role for ItgaL in NOD/LtJ T-cell activation.

CONCLUSIONS

Together, these data demonstrate that genetic deficiency of Itgb2 or ItgaL confers protection against autoimmune diabetes through distinctly different mechanisms.
Medium-Chain Fatty Acids Improve Cognitive Function in Intensively Treated Type 1 Diabetic Patients and Support In Vitro Synaptic Transmission During Acute Hypoglycemia
Authors: Page Kathleen A. , Williamson Anne , Yu Namyi , McNay Ewan C. , Dzuira James , McCrimmon Rory J. , Sherwin Robert S.
Published: February 2009

OBJECTIVE

We examined whether ingestion of medium-chain triglycerides could improve cognition during hypoglycemia in subjects with intensively treated type 1 diabetes and assessed potential underlying mechanisms by testing the effect of β-hydroxybutyrate and octanoate on rat hippocampal synaptic transmission during exposure to low glucose.

RESEARCH DESIGN AND METHODS

A total of 11 intensively treated type 1 diabetic subjects participated in stepped hyperinsulinemic- (2 mU · kg−1 · min−1) euglycemic- (glucose ∼5.5 mmol/l) hypoglycemic (glucose ∼2.8 mmol/l) clamp studies. During two separate sessions, they randomly received either medium-chain triglycerides or placebo drinks and performed a battery of cognitive tests. In vitro rat hippocampal slice preparations were used to assess the ability of β-hydroxybutyrate and octanoate to support neuronal activity when glucose levels are reduced.

RESULTS

Hypoglycemia impaired cognitive performance in tests of verbal memory, digit symbol coding, digit span backwards, and map searching. Ingestion of medium-chain triglycerides reversed these effects. Medium-chain triglycerides also produced higher free fatty acids and β-hydroxybutyrate levels compared with placebo. However, the increase in catecholamines and symptoms during hypoglycemia was not altered. In hippocampal slices β-hydroxybutyrate supported synaptic transmission under low-glucose conditions, whereas octanoate could not. Nevertheless, octanoate improved the rate of recovery of synaptic function upon restoration of control glucose concentrations.

CONCLUSIONS

Medium-chain triglyceride ingestion improves cognition without adversely affecting adrenergic or symptomatic responses to hypoglycemia in intensively treated type 1 diabetic subjects. Medium-chain triglycerides offer the therapeutic advantage of preserving brain function under hypoglycemic conditions without causing deleterious hyperglycemia.
Changes in Insulin Sensitivity and Insulin Release in Relation to Glycemia and Glucose Tolerance in 6,414 Finnish Men
Authors: Stančáková Alena , Javorský Martin , Kuulasmaa Teemu , Haffner Steven M. , Kuusisto Johanna , Laakso Markku
Published: February 2009

OBJECTIVE

We evaluated insulin sensitivity and insulin secretion across the entire range of fasting (FPG) and 2-h plasma glucose (PG), and we investigated the differences in insulin sensitivity and insulin release in different glucose tolerance categories.

RESEARCH DESIGN AND METHODS

A total of 6,414 Finnish men (aged 57 ± 7 years, BMI 27.0 ± 3.9 kg/m2) from our ongoing population-based METSIM (Metabolic Syndrome in Men) study were included. Of these subjects, 2,168 had normal glucose tolerance, 2,859 isolated impaired fasting glucose (IFG), 217 isolated impaired glucose tolerance (IGT), 701 a combination of IFG and IGT, and 469 newly diagnosed type 2 diabetes.

RESULTS

The Matsuda index of insulin sensitivity decreased substantially within the normal range of FPG (−17%) and 2-h PG (−37%) and was approximately −65 and −53% in the diabetic range of FPG and 2-h PG, respectively, compared with the reference range (FPG and 2-h PG <5.0 mmol/l). Early-phase insulin release declined by only approximately −5% within the normal range of FPG and 2-h PG but decreased significantly in the diabetic range of FPG (by 32–70%) and 2-h PG (by 33–51%). Changes in insulin sensitivity and insulin secretion in relation to hyperglycemia were independent of obesity. The predominant feature of isolated IGT was impaired peripheral insulin sensitivity. Isolated IFG was characterized by impaired early and total insulin release.

CONCLUSIONS

Peripheral insulin sensitivity was already decreased substantially at low PG levels within the normoglycemic range, whereas impairment in insulin secretion was observed mainly in the diabetic range of FPG and 2-h PG. Obesity did not affect changes in insulin sensitivity or insulin secretion in relation to hyperglycemia.
Long-Term Prognosis of Diabetic Patients With Critical Limb Ischemia
Authors: Faglia Ezio , Clerici Giacomo , Clerissi Jacques , Gabrielli Livio , Losa Sergio , Mantero Manuela , Caminiti Maurizio , Curci Vincenzo , Quarantiello Antonella , Luppattelli Tommaso , Morabito Alberto
Published: February 2009

OBJECTIVE

To evaluate the long-term prognosis of critical limb ischemia (CLI) in diabetic patients.

RESEARCH DESIGN AND METHODS

A total of 564 consecutive diabetic patients were hospitalized for CLI from January 1999 to December 2003; 554 were followed until December 2007.

RESULTS

The mean follow-up was 5.93 ± 1.28 years. Peripheral angioplasty (PTA) was performed in 420 (74.5%) and bypass graft (BPG) in 117 (20.6%) patients. Neither PTA nor BPG were possible in 27 (4.9%) patients. Major amputations were performed in 74 (13.4%) patients: 34 (8.2%) in PTA, 24 (21.1%) in BPG, and 16 (59.2%) in a group that received no revascularization. Restenosis occurred in 94 patients, bypass failures in 36 patients, and recurrent ulcers in 71 patients. CLI was observed in the contralateral limb of 225 (39.9%) patients; of these, 15 (6.7%) required major amputations (rate in contralateral compared with initial limb, P = 0.007). At total of 276 (49.82%) patients died. The Cox model showed significant hazard ratios (HRs) for mortality with age (1.05 for 1 year [95% CI 1.03–1.07]), unfeasible revascularization (3.06 [1.40–6.70]), dialysis (3.00 [1.63–5.53]), cardiac disease history (1.37 [1.05–1.79]), and impaired ejection fraction (1.08 for 1% point [1.05–1.09]).

CONCLUSIONS

Diabetic patients with CLI have high risks of amputation and death. In a dedicated diabetic foot center, the major amputation, ulcer recurrence, and major contralateral limb amputation rates were low. Coronary artery disease (CAD) is the leading cause of death, and in patients with CAD history the impaired ejection fraction is the major independent prognostic factor.
Phobic Anxiety Is Associated With Higher Serum Concentrations of Adipokines and Cytokines in Women With Diabetes
Authors: Brennan Aoife M. , Fargnoli Jessica L. , Williams Catherine J. , Li Tricia , Willett Walter , Kawachi I. , Qi Lu , Hu Frank B. , Mantzoros Christos S.
Published: February 2009

OBJECTIVE

Phobic anxiety has been associated with increased risk of cardiovascular disease (CVD), but the underlying mechanisms are poorly understood. We aimed to determine whether associations of phobic anxiety with several known markers of CVD might be contributors.

RESEARCH DESIGN AND METHODS

We used a 16-point validated index (Crown-Crisp) measured in 1988 to categorize 984 women with type 2 diabetes from the Nurses' Health Study as having low, moderate, or high phobic anxiety. Groups were then compared for differences in adipokines (adiponectin and leptin), inflammatory markers (C-reactive protein and tumor necrosis factor [TNF]-α receptor II), and markers of endothelial function (sE-selectin, soluble intercellular adhesion molecule [sICAM]-1) measured on blood samples provided between 1989 and 1990.

RESULTS

Higher levels of phobic anxiety were associated with higher BMI and lower education. Higher levels of phobic anxiety were also associated with higher leptin and soluble TNF-α receptor II in both crude analyses and after adjustment for potential confounders. sICAM and sE-selectin were higher in the highest tertile compared with the middle tertile, but there was no significant trend across tertiles. We found no association between phobic anxiety and adiponectin.

CONCLUSIONS

High levels of phobic anxiety are associated with increased levels of leptin and inflammatory markers, which may in part explain the previously observed relationship between anxiety and other psychosocial disorders with CVD.
Terminal Ileal Atresia, Total Colonic Aganglionosis, and Thrombophilia
Authors: de Chadarévian Jean-Pierre , Bouie Shondell M. , Peddinghaus Marie E. , Luck Lori R. , Schwartz Marshall Z. , Prasad Rajeev , Faerber Eric N.
Published: February 2009

Inherited thrombophilia, a predisposition for a hypercoagulable state, has been associated with cases of intestinal atresia. In this communication, we report a case of terminal ileal atresia and total colonic aganglionosis (Hirschsprung's disease), a rarely documented association, in a neonate who seemed to have a hypercoagulable state. The case stresses the need for recognition of this sequence of events in order to achieve optimal management.
Phase relations up to the solidus line in the part of the Sb-Zn-O system
Authors: Filipek Elżbieta , Dąbrowska Grażyna
Published: February 2009

Phase relations up to the solidus line in part of the Sb-Zn-O system have been investigated over the entire concentration range of the α-Sb2O4-ZnO system in air ( \( P_{O_2 } \) = 0.21 atm) using XRD and DTA/TG. The components of this system in air form ZnSb2O6 and Zn7Sb2O12. The results allow division of the system into three subsystems, i.e. α-Sb2O4-ZnSb2O6; ZnSb2O6Zn7Sb2O12 and Zn7Sb2O12-ZnO. The temperature ranges over which the ZnSb2O6 and Zn7Sb2O12 remain at equilibrium with other solid compounds depend on the gaseous atmosphere.
New paradigm of a metastable phase diagram presenting structural transformations induced by annealing of Si–C–N amorphous ceramics derived from polymer precursors
Authors: Golczewski Jerzy Andrzej
Published: February 2009

Amorphous Si – C – N domains, nanocrystalline SiC and nanocrystalline Si3N4identified in the structure of Si – C – N polymer derived ceramics (SiCN PDCs) have been proposed as metastable phases am-SICN, NASIC and NASIN. To study structural transformations of SiCN PDCs, the thermodynamic equilibria of these phases have been computed using previously derived Gibbs energies G(am-SICN), G(NASIC) and G(NASIN). The computational results are presented in the form of metastable phase diagrams. A new paradigm of these diagrams is explained as due to time dependence implemented into the Gibbs energies G(NASIC) and G(NASIN) and the application to interpretation of the crystallization course observed for SiCN PDCs is discussed.
Phase equilibria and thermal analysis in the Fe–Mn–Ni system
Authors: Zhang Lijun , Du Yong , Xu Honghui , Liu Shuhong , Liu Yajun , Zheng Feng , Dupin Nathalie , Zhou Huaiying , Tang Chengying
Published: February 2009

Based on the critical review of the experimental data available in the literature, 7 decisive ternary alloys were prepared. New phase transition temperatures and phase equilibria at 800°C in the Fe – Mn – Ni system were measured. An effective method to accurately determine phase transition temperatures from differential thermal analysis curves with overlapped peaks and nonlevel baselines within a narrow temperature range was developed. A massive transformation was observed in one quenched Fe-rich alloy. In order to make the fcc_A1 phase always in the fully disordered state in the ternary system, the effect of the binary reciprocal parameter on the Gibbs energy of ternary ordered L12 phase was considered. It was found that the introduction of only one parameter could describe all reliable experimental data in the Fe – Mn – Ni system satisfactorily. The presently obtained parameters were successfully applied in two practical cases.
Thermodynamic assessment of the Ce–Si, Y–Si, Mg–Ce–Si and Mg–Y–Si systems
Authors: Shukla Adarsh , Kang Youn-Bae , Pelton Arthur D.
Published: February 2009

The binary Ce – Si and Y – Si systems have been critically evaluated based upon available phase equilibrium and thermodynamic data, and optimized model parameters have been obtained giving the Gibbs energies of all phases as functions of temperature and composition. The liquid solution has been modeled with the Modified Quasichemical Model to account for the short-range ordering. The results have been combined with those of our previous optimizations of the Mg – Si, Mg – Ce and Mg – Y systems to predict the phase diagrams of the Mg – Ce – Si and Mg – Y – Si systems. The predictions have been compared with available data.
Matrix induced synthesis of Y3Al5O12: Ce phosphor through the Pechini method
Authors: Zhang Kai , Hu Wenbin , Li Jun , Tang Yiping , Liu Hezhou
Published: February 2009

Trivalent cerium actived yttrium aluminum garnet (YAG: Ce) phosphor was prepared using the Pechini method. Phase transition during calcination was investigated through Fourier transform infrared spectroscopy and X-ray diffraction. The results show that the powders directly transform into the pure YAG phase at 80°C. The dimension of phosphor calcined at 1200°C is micro-scale, which consists of nanometer scale primary particles. The effect of Ce doping content and calcination temperature on the luminescence properties is also discussed. The maximum emission is obtained for about 1 at.% Ce additions. The concentration quench effect is observed when Ce content increases beyond this limit. With the increment of calcination temperature, the emission intensity and lifetime increase.
Microstructure and room temperature compressive properties of holmium doped DS NiAl-Cr(Mo)-Hf eutectic alloy
Authors: Liang Y. C. , Guo J. T. , Xie Y. , Tian Y. X. , Zhou L. Z. , Hu Z. Q.
Published: February 2009

The microstructure and mechanical property of a eutectic Ni-33Al-28Cr-5.94Mo-0.05Hf-0.01Ho (holmium) alloy fabricated by using directional solidification under two withdrawal rates (3 mm min– 1 and 10 mm min– 1) are presented. It is shown that a promising as-cast microstructure is formed under the higher withdrawal rate, which can be characterized by the refinement of eutectic cells as well as eutectic lamellae between the NiAl and Cr(Mo) phases within the cells. As a positive response to this, superior room temperature mechanical properties with yield strength of 1153 MPa and compressive strain of 37 % are obtained. Based on these investigations, the mechanism responsible is discussed.
560°C isothermal section of the Zn–Fe–Ni–Si quaternary system at the zinc-rich corner
Authors: Yin Fucheng , Su Xuping , Wang Xinming , Tu Hao , Zhao Manxiu
Published: February 2009

The 560°C isothermal section of the Zn – Fe – Ni – Si quaternary system with the Zn composition being fixed at 93 at.% has been determined using optical microscopy, scanning electronic microscopy coupled with energy dispersive X-ray spectroscopy, and X-ray diffractometry. It was found that FeSi is in equilibrium with almost all phases in the section, including the δ-Fe – Zn, FeSi2, T (Zn – Fe – Ni ternary compound), γ-Ni – Zn, NiSi2 and liquid phases. The existence of the L + FeSi + NiSi2 + γ-Ni – Zn four-phase equilibrium prevents other Ni-Si compounds from entering equilibrium with the liquid phase at 560°C. No true quaternary compound was found in the present study.
Integrated approach to thermodynamics, phase relations, liquid densities and solidification microstructures in the Al–Bi–Cu system
Authors: Mirković D. , Gröbner J. , Kaban I. , Hoyer W. , Schmid-Fetzer R.
Published: February 2009

Al – Bi – Cu phase equilibria were studied using dedicated thermal analysis and microstructural investigation of slowly solidified samples. Experimentation in the most decisive Cu-rich region was enabled by developing a BN insert in combination with Ta-encapsulation for these challenging samples. A consistent thermodynamic model of the Al – Bi – Cu system is developed for the first time and applied to calculations of the entire phase diagram. The liquid miscibility gap of Al – Bi alloys extends dramatically upon addition of Cu. The density difference of the two liquids was determined in dedicated experimentation on buoyancy forces. The useful composition and temperature range for these experiments in the ternary L′ + L′′ region was provided by the thermodynamic calculations. The density data can be well interpreted on the basis of presently calculated coexisting liquid phase compositions. Finally, distinct ternary monotectic features on solidification microstructures of Al – Bi – Cu alloys are revealed and inter-related with the phase formation from thermodynamic calculations.
Prediction, determination and validation of phase diagrams via the global study of energy landscapes
Authors: Schön J. C. , Jansen M.
Published: February 2009

Traditionally, the determination of phase diagrams has followed the inductive paradigm, where experimental observations provide the phase boundaries in more or less detail and phenomenological and semi-phenomenological models are employed to interpolate between the experimental data points, and by extrapolation to predict the shape of the phase boundaries in experimentally inaccessible regions. Over the past fifteen years, a new methodology has been developing, the aim of which is the prediction, determination and validation of phase diagrams in chemical systems without any recourse to experimental information. The founding stone of this deductive approach is the global study of the energy landscape of the chemical system. In this review, we present an introduction to the concept of energy landscapes in the context of phase diagram calculations, an overview over the large variety of methods employed to study energy landscapes and compute free energies on the ab initio level, and a number of typical examples of first-principle predictions, determinations and validations of phase diagrams.
Calcium and Vitamin D IntakesIn an Adult Canadian Population
Authors: Poliquin Suzette , Joseph Lawrence , Gray-Donald Katherine
Published: February 2009

Purpose: Calcium and vitamin D intakes from food and supplements were estimated in Canadian men and women.

Methods: Calciumintakes fromboth diet and supplements and vitamin D intakes fromfortifiedmilk and supplements were estimated using cross-sectional data from9423 randomly selected subjects aged 25 years or older, who were participating in a longitudinal study on osteoporosis. Subjects completed an abbreviated food frequency questionnaire administered by a trained interviewer between July 1995 and December 1997.

Results: Themean (standard deviation) daily intake for calciumwas estimated to be 1038 (614)mg for women and 904 (583)mg formen; for vitamin D,mean intakes were 5.6 (5.9) μg and 4.8 (5.5) μg for women andmen, respectively.

Conclusions: Mean intakes for calcium and vitamin D in men and women under age 51 were close to the adequate daily intake levels. Older adults, however, may be at risk of deficiency.
The Experimental Ordinary: Deleuze on Eating and Anorexic Elegance
Authors: Arsic Branka
Published: February 2009

The paper discusses Deleuze's concept of the feminine through exploration of the questions of eating, cooking, and specifically anorexia, as well as an ‘anorexic relation’ to fashion and dressing. It argues that anorexia should be understood as a micro-political experimentation in fashioning one's own body on its flight to becoming woman. In accordance with Deleuze's ontology of the surface, the anorexic body can be seen as the invention of the BWO that forms an assemblage with clothes and, in so becoming different, invents for itself different desires.
MolBank: What Is It Good for?
Authors: Haider Norbert
Published: February 2009

From time to time, the Publisher and the Editor-in-Chief of MolBank are asked the question: “what is the purpose of publishing a journal like MolBank?” We think that the start of a new year is a good opportunity to make the ideas behind such a journal as clear as possible to our readers, authors and reviewers. In principle, the answer to this question might be boiled down to a single term: “usefulness”. But allow me to go a little bit more into detail. [...]
Polyfunctional Nitriles in Organic Syntheses: A Novel Route to Aminopyrroles, Pyridazines and Pyrazolo[3,4-c]pyridazines
Authors: Al-Mousawi Saleh M. , Moustafa Moustafa Sherief , Meier Herbert , Kolshorn Heinz , Elnagdi Mohamed Hilmy
Published: February 2009

Phenacylmalononitrile 1 reacts with dimethylformamide dimethyl acetal to yield an enaminone which could be readily converted into a pyrrole or an aminopyridazine by treating with ammonium acetate and hydrazine hydrate, respectively. Compound 1 reacted with hydrazine hydrate in ethanol at room temperature to yield the dihydropyridazine 9 as a single product. In refluxing ethanol this product further reacted with hydrazine hydrate to yield the novel dihydropyrazolopyridazinamine 10.
Un sceau-cylindre inédit de Tell Khuera (Syrie du Nord) et sa place au sein de la glyptique géométrique du Bronze ancien en Mésopotamie
Authors: Quenet Philippe
Published: February 2009

Résumé J. Lauffray mena une courte campagne à Tell Khuera, dans le Nord syrien, en 1955. Parmi les nombreux objets sortis de cette fouille figure un sceau-cylindre de belle facture, inédit et aujourd’hui conservé et exposé au Musée National de Damas, Syrie. Orné de motifs géométriques, il se rapproche de plusieurs autres exemplaires venant principalement du Sud mésopotamien. L’étude de cette série glyptique confirme sans ambiguïté l’existence d’une production de sceaux-cylindres de style géométrique dans le troisième quart du III e millénaire av. J.-C. Cette série n’est d’ailleurs pas isolée : l’analyse d’un certain nombre de compositions plus ou moins apparentées, jointe à la prise en compte des contextes de trouvaille, permet en effet d’attribuer ou de réattribuer à la fin du D.A. III ou au début d’Agadé quantité de sceaux-cylindres et d’empreintes, même s’il reste indéniable que la période d’élection du style géométrique dans le domaine glyptique fut le début du III e millénaire av. J.-C. En revanche, le corpus disponible à ce jour permet difficilement d’établir la réalité d’une filiation entre les séries des débuts et du milieu du Bronze Ancien.
Anatomie animale : le festin carné des dieux d'après les textes hittites III. le traitement des viandes
Authors: Mouton Alice
Published: February 2009

Résumé Après avoir examiné, dans deux articles précédents, les parties du corps animal que les dieux de l’Anatolie hittite étaient à même de consommer, il s’agit de déterminer ici les traitements que subissaient les viandes consacrées ( šuppa ) lors du rituel sacrificiel. Ces opérations sont de nature variée : après avoir consacré, abattu et débité la victime sacrificielle, on cuit ou non les morceaux de viande consacrés, puis on les dépose devant l’effigie divine. Après ce dépôt qui a manifestement valeur d’oblation, les hommes récupèrent parfois les viandes consacrées pour leur propre consommation. Pour chacune de ces étapes du sacrifice, une infinité de variantes est attestée par les textes hittites, ce qui vient aussi bien de la diversité des contextes rituels que des différentes traditions régionales.
Les conceptions de Winnicott sur le masculin et le féminin
Authors: Lehmann Jean-Pierre
Published: February 2009

En s’appuyant sur sa clinique, Winnicott a élaboré une théorie originale de la bisexualité. Il distingue chez l’homme comme chez la femme, un élément masculin s’appuyant sur la pulsion et un élément féminin qui n’a rien de pulsionnel. L’élément masculin « fait » tandis que l’élément féminin (chez les hommes et chez les femmes) « est ». Il est le fondement de la capacité d’« être » et plus tard d’un sentiment du self. Il ne peut être adéquatement transmis que par un sein maternel capable d’être et non de faire.