bluuebunny/crossref_metadata_2025_split huggingface dataset:
Field Scale Production Decline Characteristics During Gravity Drainage
Authors: Sahni Akshay , Beeson Dale , DiCarlo David A. 
Published: March 2012

Abstract
Gas or steam gravity drainage is a very efficient recovery mechanism. Field observations, laboratory studies and pore network modeling have pointed towards very low residual oil saturations and high recovery with gravity drainage. While work during the last three decades has focused on understanding the physics of three-phase flow, literature on field scale gravity drainage production decline characteristics is somewhat limited. Understanding field level production decline characteristics is important as it enables better production forecasting, resource estimation and reservoir management.
In this paper production data from two fields under gravity drainage is evaluated and it shows strong exponential decline characteristics. After an initial period of rapid decline, there is a period of lower decline for a long period of time. The paper relates field scale observations of gravity drainage to laboratory observations of gravity drainage in long cores. The laboratory experiments show similar behaviors where a period of initial rapid decline is followed by a long period of lower&lt;br/&gt; decline, resulting in very low remaining oil saturation in the gas invaded zone. The paper discusses physics of gravity drainage displacement and summarizes similarities and differences between field and laboratory observations.
Disability in a Community Population with MS with and without Mental Disorders
Authors: Patten Scott B. , Williams Jeanne V. A. , Lavorato Dina H. , Metz Luanne M. , Bulloch Andrew G. M. 
Published: March 2012

Objective: Psychiatric conditions are known to have a detrimental impact on functioning and may therefore influence patterns of disability associated with MS. Population-based studies are needed to evaluate such interactions. The objective of this study was to describe the pattern of interaction of MS and mental disorders on health-related impairments. Methods: The Participation and Activity Limitation Survey (PALS) was a post-censual survey conducted by Statistics Canada in association with the 2006 Canadian Census. PALS collected detailed data from a random sample of n = 28,640 respondents with health-related impairments reported on their census form. The PALS interview collected self-reported diagnostic data and included scales to assess functioning and participation in society. Results: PALS identified 245 individuals with MS, leading to an estimated (weighted) population prevalence of 0.2% (200 per 100,000), consistent with other Canadian estimates. As expected, impaired agility, vision, communication, mobility, pain, and memory were strongly associated with MS. Mental disorders were also associated with impairment, but interactions between these conditions and MS were generally not evident. Conclusions: Mental disorders are associated with a higher level of disability in MS but, with the exception of communication, there was no evidence of synergistic interaction between mental disorders and MS in contributing to health-related impairments.
Multi-residue analytical methods for the determination of pesticides and PPCPs in water by LC-MS/MS: a review
Authors: Primel Ednei , Caldas Sergiane , Escarrone Ana 
Published: March 2012

Abstract
Residues of pesticides, pharmaceutical and personal care products (PPCPs) are contaminants of world-wide concern. Consequently, there is a growing need to develop reliable analytical methods, which enable rapid, sensitive and selective determination of these pollutants in environmental samples, at trace levels. In this paper, a review of the liquid chromatography-tandem mass spectrometry (LC-MS/MS) based methods for the determination of pesticides and PPCPs in the environment is presented. Advanced aspects of current LC-MS/MS methodology, including sample preparation and matrix effects, are discussed.
Chromatographic techniques in analysis of cyclooxygenase-2 inhibitors in drugs and biological samples
Authors: Starek Małgorzata , Dąbrowska Monika 
Published: March 2012

Abstract
Non-steroidal anti-inflammatory drugs, as a therapeutic class, are among the most often used active pharmaceutical ingredients in heath care in the world. They are mostly available without prescription and often used for treatment of fever and pain. An extensive research of the literature published in analytical and pharmaceutical chemistry journals has been conducted and the chromatographic methods which were used for the purity, stability and pharmacokinetic studies of the cyclooxygenase-2 inhibitors, in formulations and biological materials have been reviewed. The methodology for the analysis of selected drugs is very well documented and many examples are available in the literature. The common use of chromatographic techniques with various detection attachments provide possibility for monitoring of drugs in therapy.
Accurate calculation of the eigenvalues of non-uniform strings and membranes
Authors: Amore Paolo , Fernandez Francisco , Rodriguez Martin 
Published: March 2012

Abstract
We describe a pseudospectral approach which combines a mapping procedure with the principle of minimal sensitivity to obtain accurate estimates for the eigenvalues of non-uniform strings and both uniform and nonuniform membranes. We illustrate the method on specific examples, including the case of a cross shaped membrane, with arms of infinite length.
A mixed active and passive GLR test for a fault tolerant control system
Authors: Jamouli Hicham , El Hail Mohamed , Sauter Dominique 
Published: March 2012

A mixed active and passive GLR test for a fault tolerant control system
This paper presents an adaptive Generalized Likelihood Ratio (GLR) test for multiple Faults Detection and Isolation (FDI) in stochastic linear dynamic systems. Based on the work of Willsky and Jones (1976), we propose a modified generalized likelihood ratio test, allowing detection, isolation and estimation of multiple sequential faults. Our contribution aims to maximise the good decision rate of fault detection using another updating strategy. This is based on a reference model updated on-line after each detection and isolation of one fault. To reduce the computational requirement, the passive GLR test will be derived from a state estimator designed on a fixed reference model directly sensitive to system changes. We will show that active and passive GLR tests will be mixed and give interesting results compared with the GLR of Willsky and Jones (1976), and that they can be easily integrated in a reconfigurable Fault-Tolerant Control System (FTCS) to asymptotically recover the nominal system performances of the jump-free system.
Signed directed graph based modeling and its validation from process knowledge and process data
Authors: Yang Fan , Shah Sirish , Xiao Deyun 
Published: March 2012

Signed directed graph based modeling and its validation from process knowledge and process data
This paper is concerned with the fusion of information from process data and process connectivity and its subsequent use in fault diagnosis and process hazard assessment. The Signed Directed Graph (SDG), as a graphical model for capturing process topology and connectivity to show the causal relationships between process variables by material and information paths, has been widely used in root cause and hazard propagation analysis. An SDG is usually built based on process knowledge as described by piping and instrumentation diagrams. This is a complex and experience-dependent task, and therefore the resulting SDG should be validated by process data before being used for analysis. This paper introduces two validation methods. One is based on cross-correlation analysis of process data with assumed time delays, while the other is based on transfer entropy, where the correlation coefficient between two variables or the information transfer from one variable to another can be computed to validate the corresponding paths in SDGs. In addition to this, the relationship captured by data-based methods should also be validated by process knowledge to confirm its causality. This knowledge can be realized by checking the reachability or the influence of one variable on another based on the corresponding SDG which is the basis of causality. A case study of an industrial process is presented to illustrate the application of the proposed methods.
Sliding mode methods for fault detection and fault tolerant control with application to aerospace systems
Authors: Edwards Christopher , Alwi Halim , Tan Chee 
Published: March 2012

Sliding mode methods for fault detection and fault tolerant control with application to aerospace systemsSliding mode methods have been historically studied because of their strong robustness properties with regard to a certain class of uncertainty, achieved by employing nonlinear control/injection signals to force the system trajectories to attain in finite time a motion along a surface in the state-space. This paper will consider how these ideas can be exploited for fault detection (specifically fault signal estimation) and subsequently fault tolerant control. It will also describe applications of these ideas to aerospace systems, including piloted flight simulator results associated with the GARTEUR AG16 Action Group on Fault Tolerant Control. The results demonstrate a successful real-time implementation of the proposed fault tolerant control scheme on a motion flight simulator configured to represent the post-failure EL-AL aircraft.
Model-free reconfiguration mechanism for fault tolerance
Authors: Jain Tushar , Yamé Joseph , Sauter Dominique 
Published: March 2012

Model-free reconfiguration mechanism for fault toleranceThe problem of fault tolerant control is studied from the behavioral point of view. In this mathematical framework, the concept of interconnection among the variables describing the system is a key point. The problem is that the behavior we intend to control is not known. Therefore, we are interested in designing a fault accommodation scheme for an unknown behavior through an appropriate behavioral interconnection. Here we deal simply with the trajectories that are generated by the system in real time. These trajectories determine the behavior of a system in various (faulty/healthy) modes. Based on the desired interconnected behavior, only the trajectories that obey certain laws are selected. These laws, representing the desired behavior, can indeed be achieved by a regular interconnection. Thus, when the trajectories do not belong to a certain desired behavior, it is considered to be due to the occurrence of a fault in the system. The vantage point is that the fault tolerant control problem now becomes completely a model-free scheme. Moreover, no explicit fault diagnosis module is required in our approach. The proposed fault tolerance mechanism is illustrated on an aircraft during the landing phase.
Reconfigurable control design with integration of a reference governor and reliability indicators
Authors: Weber Philippe , Boussaid Boumedyen , Khelassi Ahmed , Theilliol Didier , Aubrun Christophe 
Published: March 2012

Reconfigurable control design with integration of a reference governor and reliability indicatorsA new approach to manage actuator redundancy in the presence of faults is proposed based on reliability indicators and a reference governor. The aim is to preserve the health of the actuators and the availability of the system both in the nominal behavior and in the presence of actuator faults. The use of reference governor control allocation is a solution to distribute the control efforts among a redundant set of actuators. In a degraded situation, a reconfigured control allocation strategy is proposed based on on-line re-estimation of the actuator reliability. A benefit of incorporating reliability indicators into over-actuated control system design is the smart management of the redundant actuators and improvement of the system safety. Moreover, when the fault is severe, an adaptation approach using the reference governor is proposed. The reference governor unit is a reference-offset governor based on a discrete-time predictive control strategy. The idea is to modify the reference according to the system constraints, which become stricter after the occurrence of an actuator fault. The proposed approach is illustrated with a flight control application.
LPV design of fault-tolerant control for road vehicles
Authors: Gáspár Péter , Szabó Zoltán , Bokor József 
Published: March 2012

LPV design of fault-tolerant control for road vehiclesThe aim of the paper is to present a supervisory decentralized architecture for the design and development of reconfigurable and fault-tolerant control systems in road vehicles. The performance specifications are guaranteed by local controllers, while the coordination of these components is provided by a supervisor. Since the monitoring components and FDI filters provide the supervisor with information about the various vehicle maneuvers and the different fault operations, it is able to make decisions about necessary interventions into the vehicle motions and guarantee reconfigurable and fault-tolerant operation of the vehicle. The design of the proposed reconfigurable and fault-tolerant control is based on an LPV method that uses monitored scheduling variables during the operation of the vehicle.
Experimental and numerical investigation of electrostatic spray liquid-liquid extraction with ionic liquids
Authors: Krawczyk Marek , Kamiński Kamil , Petera Jerzy 
Published: March 2012

Experimental and numerical investigation of electrostatic spray liquid-liquid extraction with ionic liquids
A new concept of an electrostatic spray column for liquid-liquid extraction was investigated. An important problem for separation processes is the presence of azeotropic or close-boiling mixtures in their production, for example heptane with ethanol, since the separation is impossible by ordinary distillation. The use of ionic liquids (IL) as a dispersed solvent specially engineered for any specific organic mixture in terms of selectivity is a key factor to successful separation. As IL present particularly attractive combination of favorable characteristics for the separation of heptane and ethanol, in this work we use 1-butyl-3-methylimidazolium methyl sulfate [BMIM][MeSO4]. Because of high viscosity and relatively high cost of IL a new technique was introduced, consisting in the electrostatically spray generation to enhance the mass transport between the phases. In order to optimally design the geometry of the contactor a series of numerical simulation was performed. Especially multi-nozzle variants for better exploitation of contactor volume were investigated. Experiments showed excellent possibility of control of the dispersion characteristics by applied voltage and thus control of the rate of extraction. The preliminary simulations based on our mathematical model for a three nozzle variant exhibited visual agreement with the theory of electrostatics.
Thermal and thermo-catalytic conversion of waste polyolefins to fuel-like mixture of hydrocarbons
Authors: Stelmachowski Marek , Słowiński Krzysztof 
Published: March 2012

Thermal and thermo-catalytic conversion of waste polyolefins to fuel-like mixture of hydrocarbons
Results of the investigation of thermal degradation of polyolefins in the laboratory-scale set-up reactors are presented in the paper. Melting and cracking processes were carried out in two different types of reactors at the temperature of 390-420°C. This article presents the results obtained for conversion of polyolefin waste in a reactor with a stirrer. Next, they were compared with the results obtained for the process carried out in a reactor with a molten metal bed, which was described in a previous publication. For both processes, the final product consisted of a gaseous (2-16 % mass) and a liquid (84-98 % mass) part. No solid product was produced. The light, "gasoline" fraction of the liquid hydrocarbons mixture (C4-C10) made up over 50% of the liquid product. The overall (vapor) product may be used for electricity generation and the liquid product for fuel production.
Sustainability and the Scholarly Enterprise
Authors: Seaman John T. , Graham Margaret B. W. 
Published: March 2012

This article analyses the origins, development, and impact of Gutenberg-e, a digital publishing program in historical scholarship sponsored by the American Historical Association (AHA), with the support of the Andrew W. Mellon Foundation. Intended as an experiment in developing and legitimizing new modes of historical scholarship, Gutenberg-e quickly evolved, under pressure to become economically sustainable, into a traditional publishing enterprise bent on making books cheaper and paying for itself in the process. Digital technology, which had the power to transform the whole scholarly enterprise, instead became a means to shore up the existing system of scholarly publishing, with all its flaws intact. Though Gutenberg-e has much to teach us about the costs and consequences of that system, especially for the scholars it is meant to serve, it also offers a glimpse of an alternative future. Almost in spite of itself, Gutenberg-e produced a handful of innovative works of digital scholarship, experimented with new forms of scholarly collaboration and community, and highlighted the opportunities of an expanded audience for specialized academic work. These modest achievements suggest the potential of digital technology to create things which scholars value and thereby sustain the scholarly enterprise over the long term.
Morbidity profile following aggressive resection of parietal lobe gliomas
Authors: Sanai Nader , Martino Juan , Berger Mitchel S. 
Published: March 2012

Object
The impact of parietal lobe gliomas is typically studied in the context of parietal lobe syndromes. However, critical language pathways traverse the parietal lobe and are susceptible during tumor resection. The authors of this study reviewed their experience with parietal gliomas to characterize the impact of resection and the morbidity associated with language.

Methods
The study population included adults who had undergone resection of parietal gliomas of all grades. Tumor location was identified according to a proposed classification system for parietal region gliomas. Low- and high-grade tumors were volumetrically analyzed using FLAIR and T1-weighted contrast-enhanced MR imaging.

Results
One hundred nineteen patients with parietal gliomas were identified—34 with low-grade gliomas and 85 with high-grade gliomas. The median patient age was 45 years, and most patients (53) presented with seizures, whereas only 4 patients had an appreciable parietal lobe syndrome. The median preoperative tumor volume was 31.3 cm3, the median extent of resection was 96%, and the median postoperative tumor volume was 0.9 cm3. Surprisingly, the most common early postoperative neurological deficit was dysphasia (16 patients), not weakness (12 patients), sensory deficits (14 patients), or parietal lobe syndrome (10 patients). A proposed parietal glioma classification system, based on surgical anatomy, was predictive of language deficits.

Conclusions
This is the largest reported experience with parietal lobe gliomas. The findings suggested that parietal language pathways are compromised at a surprisingly high rate. The proposed parietal glioma classification system is predictive of postoperative morbidity associated with language and can assist with preoperative planning. Taken together, these data emphasize the value of identifying language pathways when operating within the parietal lobe.
Novel strategy to treat a case of recurrent lymphocytic hypophysitis using rituximab
Authors: Schreckinger Matthew , Francis Todd , Rajah Gary , Jagannathan Jay , Guthikonda Murali , Mittal Sandeep 
Published: March 2012

Lymphocytic hypophysitis is an uncommon autoimmune condition that often results in significant morbidity. Although most cases resolve spontaneously or after a short course of steroids, rarely, refractory cases can cause persistent neurological deficits despite aggressive medical and surgical management.
A 41-year-old woman presented with progressive visual loss in the left eye and was found to have a sellar mass. She underwent transsphenoidal surgery because of lesion enlargement. Histopathology was consistent with adenohypophysitis with B-cell predominance. Despite steroid treatment, her neurological condition worsened and she experienced loss of vision in the right eye. Craniotomy with decompression of the right optic nerve was performed. Her condition improved initially, but she continued to have progressive visual compromise over the following months. She was therefore treated with rituximab, a monoclonal antibody against B cells. Her vision improved significantly within a few weeks. There was no clinical or radiographic exacerbation 2 years after starting immunotherapy.
Rituximab, an anti-CD20 antibody that specifically depletes B lymphocytes, can be an effective treatment strategy for patients with steroid-refractory, B cell–predominant lymphocytic hypophysitis.
Assessing the Performance of Imaging Health Systems in Five Selected Hospitals in Uganda
Authors: Kawooya Michael G. , Pariyo George , Malwadde Elsie Kiguli , Byanyima Rosemary , Kisembo Harriet 
Published: March 2012

Objectives:
The first objective of the study was to develop an index termed as the ‘Imaging Coverage’ (IC), for measuring the performance of the imaging health systems. This index together with the Hospital-Based Utilization (HBU) would then be calculated for five Ugandan hospitals. Second, was to relate the financial resources and existing health policy to the performance of the imaging systems.

Materials and Methods:
This was a cross-sectional survey employing the triangulation methodology, conducted in Mulago National Referral Hospital. The qualitative study used cluster sampling, in-depth interviews, focus group discussions, and self-administered questionnaires to explore the non-measurable aspects of the imaging systems’ performances.

Results:
The IC developed and tested as an index for the imaging system′s performance was 36%. General X-rays had the best IC followed by ultrasound. The Hospital-Based Utilization for the five selected hospitals was 186 per thousand and was the highest for general radiography followed by ultrasound.

Conclusion:
The IC for the five selected hospitals was 36% and the HBU was 186 per thousand, reflecting low performance levels, largely attributable to inadequate funding. There were shortfalls in imaging requisitions and inefficiencies in the imaging systems, financing, and health policy. Although the proportion of inappropriate imaging was small, reducing this inappropriateness even further would lead to a significant total saving, which could be channeled into investigating more patients. Financial resources stood out as the major limitation in attaining the desired performance and there is a need to increase budget funding so as to improve the performance of the imaging health systems.