bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Prognostic Value of Previous Irradiation on Survival of Bladder Cancer Patients
Authors: Krughoff Kevin , Lhungay Tamara P. , Barqawi Zuhair , O’Donnell Colin , Kamat Ashish , Wilson Shandra 
Published: October 2015

Background: Radiation exposure is an established risk factor for bladder cancer, however consensus is lacking on the survival characteristics of bladder cancer patients with a history of radiation therapy (RT). Confounding patient comorbidities and baseline characteristics hinders prior attempts at developing such a consensus. Objective: To compare the survival characteristics of patients with suspected radiation-induced second primary cancer (RISPC) of the bladder to those with de novo bladder cancer, taking into account the patient comorbidities and baseline characteristics predictive of survival. Methods: Retrospective analysis of patients with muscle-invasive (≥T2a) or BCG-refractory stage Tis-T1 urothelial bladder cancer. Patients were excluded if prior RT exposure was used as treatment for bladder cancer or if cause of death was due to post-operative complications. A digit matching propensity score algorithm was used to match patients with prior radiation treatment to those without prior treatment. Cox regression analysis for time until death was performed following creation of the propensity score matched sample. Results: 29 patients with history of RT were matched with two controls each, resulting in a dataset of 87 observations in the event model. Results from the Cox model indicate a significantly increased hazard ratio for death at 2.22 ( p = 0.047, 95% CI: 1.015–4.860) given a history of prior radiation therapy. Conclusions: In a small cohort, bladder cancer patients who underwent cystectomy had a significantly higher risk of death in the face of prior pelvic RT. This effect was found to be independent of surgical complications, numerous established patient characteristics and comorbidities traditionally predictive of survival.
World's First: Annular Barrier Installed in a Subsea, Deepwater Well without the Use of Cement
Authors: Jacinto C. C. , Nardi L. , Da Silva M. F. , Marques M. , Esteves P. , Maciel P. , Vasques R. Reves 
Published: October 2015

It is widely recognized throughout the industry that as wells get deeper and well trajectories get more complex, the challenge to establish effective cement for zonal isolation (ZI) increases.
This paper will present the results of the world's first installation of a cementless liner using state-of-the-art well annular barrier technology within a subsea, deepwater, pre-salt well in Brazil. This new method demonstrates that maintaining an open sand face delivers lower skin and potentially higher productivity.
A New Boosting Concept: Pumps Installed Inside Production Risers in FPSOs
Authors: Rodrigues R. , Foresti B. P. , Vieira T. S. , de Franca A. B. 
Published: October 2015

In oilfield exploitation, pumping is one of the most productive artificial lift methods. The use of downhole pumps, where applicable, allows increasing production. However, service life of this type of systems may be short, around 2.5 years for electrical submersible pumps - ESPs, one of the most widely used types. Furthermore, failures in wet completion subsea wells require tubing removal, a heavy workover operation, demanding high costs offshore rigs. Besides, due to production halt, revenues are impacted.
As a tendency for subsea wells, whenever allowed by production conditions, pumps are installed on the seabed, outside the production well. Depending upon the free gas fraction at pump intake, ESPs (with or without previous gas separation) or multiphase pumps may be used.
Examples of ESP usage outside the producing wells are the pumping module (MOBO) and the Skid-ESP. In such cases, ESPs strings are installed on the seabed. In cases of failure, ESP replacement is simpler and faster, executed by rigs or special vessels, avoiding the costly intervention in the production well. But, even saving resources due to the operation simplification, the costs of required naval resources and the time spent awaiting for their availability and mobilization are still high. Several days may pass from system failure until the intervention is finally performed.
At Perdido and Nansen Spar platforms, operated by Shell and Anadarko respectively, ESP were deployed and installed in the production risers. Recent developments of compact and high speed ESP may contribute for their placement inside production risers for other production unit types, FPSO, for instance.
This paper proposes a new boosting concept based pumps, ESP or Hydraulic Submersible Pumps - HSP, installed inside production risers in FPSO, comparing their advantages and disadvantages of the proposed concept to seabed ESP systems, multiphase pumps and gas-liquid separation systems.
Classification Society Studies on FPSO Life Extension Requirements
Authors: Machado C. L. , Wu J. , Huang W. 
Published: October 2015

The last couple of decades have seen the conversion of a large number of trading tankers into floating production, storage, and offloading units (FPSOs). ABS records indicate that about a fifth of the worldwide FPSO fleet is approaching the end of its designed service life, with a significant number of these operating in Brazilian waters. Meanwhile, new discoveries in pre-salt reservoirs and the recent proven technologies for oil recovery have been pushing operators and concessionaires to extend oil production in these fields beyond their originally predicted life. Additionally, recent pre-salt oil developments offshore Brazil have increased the demand for new units. The result of these developments is a stated industry need to extend the service lives of existing FPSOs.
This need in association with the refinement of environmental data and enhancement of Rules requires the verification of the adequacy of the FPSO unit to withstand the design operational loads, and its updates, refurbishments and additional equipment using currently available engineering tools for numerical simulations and the current Code and Class Rule requirements.
A new methodology to review these units employing state-of-art technology tools was developed using studies comparing existing FPSO arrangements based on prescriptive classification rule requirements and finite element analyses. Comparisons were performed between the results of these analyses and the original approved design data. Such comparisons are significant in understanding FPSO structural capacity at the conversion stage, its performance during its intended service, and its remaining service life. Differences were mapped and the reasons for these differences were investigated to determine typical engineering procedures needed for predicting the estimated remaining service life. The resulting approach is a new method for evaluating the remaining structural life of existing FPSOs.
This approach also enlists an in-service inspection program to provide the necessary information regarding structural degradation during years of operation, previous repairs, and the most current condition. A similar approach also can be used for other hull forms.
Fulfilling Local Content Requirements Within The First Six Months of Country Operation: A Case Study
Authors: MacDonald S. , Shah B. , Almeida C. , Daher E. 
Published: October 2015

In Latin America, a Company required the provision of H2S and CO2 safety services for ten offshore drilling rigs with an extremely tight timeline. The operator decided to choose a safety solutions provider based in North America to provide the services. As a new player in the region, a major challenge was to comply with operator and government requirements to have 60% local content at project launch.A methodology of accelerated nationalization of the workforce was put in place. This methodology covers all the elements of sourcing, recruiting, onboarding, integrating and operating phases for any new worker joining the new operation. With a mobilization of local language-speaking process excellence supervisors from its African operations, this was a key initiative to the accelerated success of this methodology. During the transition period, the African supervisors conducted an intensive New Hire Program for all local nationals. The training was in addition to those required by the government and the operator. The technical team also customized and localized the corporate Quality Management System (QMS) that was delivered in time for the training period.Within the first month of operation, 75% local content was achieved. Through on-the-job training and mentoring by the African supervisors, the Nationals quickly transitioned into Onsite H2S / CO2 Technicians. In turn, the African Supervisors transitioned into Quality Control Supervisors. The mobilization of the African supervisors from a similar offshore safety project was aimed at overcoming initial language and cultural barriers. Learning from previous country start-up experience, miscommunication and misunderstanding due to language and cultural barriers has the potential to cause unnecessary cost and project delays. Twelve months after project launch, 100% local content was achieved with the capacity to support further expansion.The company developed a nationalization program designed to promote career development and core competency progression to retain the local, national workforce, increase loyalty and continuously improve safety standards wherever they operate. This case study discusses the value of a adopting a sound local content program with a view to sustaining a long- term presence in the region.
A Simulation Model for Electromagnetic Wave Propagation Within Production Pipes of Oil Wells
Authors: Cunha A. A. L. , Pacheco M. A. 
Published: October 2015

Abstract
The propagation of electromagnetic waves within oil production pipes has been studied, taking into account the variation in oil temperature along the pipe. This work shows the development of a simulation model under uncertainties, which is able to simulate the electromagnetic propagation in an inhomogeneous medium by dividing the production pipe into smaller pipe segments, each one approximately homogeneous (constant electrical conductivity). In each segment, the model assumes that the electrical conductivity of oil is a constant and, therefore, the sub pipe is a homogeneous medium. Within each homogeneous medium, the solution is analytically represented by an expansion in basis functions (called modes), that are obtained by the solution of the vector wave equation in a cylinder with lossless walls. Boundary conditions are then applied between adjacent segments to ensure the continuity of both the electric field and the magnetic field, leading into a system of linear equations on the coefficients of the series expansion in basis functions. The solution of this linear system gives the fields in each pipe segment, thus solving the original inhomogeneous problem. In order to account for uncertainties, Monte-Carlo sampling has been used to add small perturbations to pre-defined oil conductivity profiles along the production pipe. The results show that this model can simulate a thousand of scenarios in less than a second, thus making it ideal for use with optimization algorithms which objective function depends on simulating the propagation of electromagnetic waves inside the well.
Evaluation of Local Joint Flexibility Effects in Fixed Oil Platforms
Authors: Martins J. L. , Silva R. P. 
Published: October 2015

Most of the fixed offshore platforms installed in Brazil are reaching or exceeding their design life. Even with the sharp fall in oil prices and the discovery of new oil fields, many of these installations remain economically viable in spite of their age; therefore, there is a need to extend their operational life. To ensure the platform structural integrity, the most sensitive structural joints and elements are systematically inspected. These inspections are based on structural analyses that identify all elements in which the working stress or design life do not comply with adopted codes. Underwater inspections can be difficult and very expensive. The use of local joint flexibility can lead to a reduction in the number of joints to be inspected. For that reason, this work aims to present an evaluation of the effects using methodologies of local joint flexibility.
This work was conducted for six fixed oil platforms installed in Brazil between 1988 and 2012 with water depths ranging from 82m to 177m and was fully developed using finite element software. The analysis results were obtained taking into account three distinct methodologies of local joint flexibility and compared to the standard model, without considering local joint flexibility. The influence of different parameters were evaluated, such as water depth, natural frequency, maximum displacement, ratio between brace to chord diameter (d/D), ratio between chord diameter to chord wall thickness (D/T), angle between chord and brace axial and bending stresses.
The results allowed a better understanding of each parameter influence and the impact that each methodology has in punching shear verification and in the structural behavior of the global model. In some analyzed offshore platforms the results indicated that the consideration of local joint flexibility may produce significant reduction in punching shear stress ratio, while at the same time enables an identification of critical joints that may have been over looked otherwise.
Big Data Analytics for Predictive Maintenance Modeling: Challenges and Opportunities
Authors: Santos I. H. F. , Machado M. M. , Russo E. E. , Manguinho D. M. , Almeida V. T. , Wo R. C. , Bahia M. , Constantino D. J. S. , Salomone D. , Pesce M. L. , Souza C. , Oliveira A. C. , Lima A. , Gois J. , Tavares L. G. , Prego T. , Netto S. , Silva E. 
Published: October 2015

Big data analytics, applied in the industry to leverage data collection, processing and analysis, can allow a better understanding of production system's abnormal behavior. This knowledge is essential for the adoption of a proactive maintenance approach instead of conventional time-based strategies, leading to a paradigm shift towards Condition-Based Maintenance (CBM) since decision is now based on the usage of a huge, diverse, and dynamic amounts of data as a means to optimize operational costs. This paper reports an investigation of the emerging aspects in the design and implementation of big data analytics solutions for offshore installations in order to allow predictive maintenance practices.
Condition-based maintenance focuses on performing interventions based on the actual and future states (health) of a system by monitoring the underlying deterioration processes. One of the building blocks of a CBM design and implementation is the prognostic approach/system, which aims to detect, classify and predict critical failures. Considering the massive amounts of data available from a Stationary Production Unity (SPU), the use of techniques that properly deal with such a big data scenario became essential. The use of parallel processing to ingest, transform, and analyze different kinds of data in near real-time basis allows the construction of a valuable tool for implementing CBM.
This paper presents a comparison of different approaches for RUSBoost and Random Forest (RF) classification, in constructing a prognostic system for a specific class of turbogenerator failures from a chosen Petrobras' Floating Production Storage and Offloading (FPSO). Besides the comparison of different classifiers, a contribution of this work lies on the use of data acquired not only from machine sensors (telemetry data) but also non-structured data regarding the most critical failures acquired from official reports, e.g. operator's machine event annotations. Those reported annotations were correlated to telemetry data to identify real critical failures, and simultaneously avoid false positives.
A Methodology to Incorporate the Phase Equilibrium Kinetics in a Compositional Reservoir Simulator
Authors: Santos L. O. S. , Rios V. S. , Lins A. G. , Oliveira T. D. S. 
Published: October 2015

Commercial compositional reservoir simulators do not consider the kinetic effects in the phase equilibrium calculation. Phase equilibrium is calculated using a conventional flash. Therefore, there is an instantaneous equilibrium between the injected gas and the reservoir fluid. In most cases, this is a reasonable assumption, since the gas will be in contact with the reservoir fluid for a long period of time. There are cases though, where miscibility plays an important role in the total recovery and where the instantaneous equilibrium can be an optimistic assumption.
This work aims at implementing a methodology to incorporate the kinetic effects of the phase equilibrium in a compositional reservoir simulator. The methodology was inspired in the "DRSDT" keyword widely used in black oil simulators. In this methodology, the maximum solubilization ratio is defined by the user and the fugacity equations were modified to guarantee that this target would never be violated.
The implementation was tested for different scenarios using real field data. The main objective of these simulations was to evaluate the importance of the kinetic effects for different fluid models and different injected gas compositions. These analyses demonstrated to be rather challenging, since there is a lack of experimental data in the literature. Therefore, a workflow was developed that isolates the phenomenon analyzed. Using this workflow, we could evaluate three different real fluid models and the importance of phase equilibrium kinetics on the recovery forecast.
Singing Mitigation in Corrugated Risers by Liquid Injection
Authors: Golliard J. , Belfroid S. , Lunde K. 
Published: October 2015

In the last few decades, flexible risers have increasingly been used in the offshore oil and gas industry. In gas applications these risers can generate high amplitude tonal pressure fluctuations when the gas velocity reaches a threshold value. The resulting pressure fluctuations can then cause high vibration and cyclic stress levels in the associated topside and subsea pipe work. On a number of platforms, riser pulsations have led to serious limitations of the production capability and in at least one case to the fatigue failure of two small bore side branches, resulting into a shutdown of the platform for five months.
An acoustic assessment can be performed to determine the risks of a flexible riser to be a source of Flow-Induced Pulsations (FIP) within its intended operating envelope. This assessment is based on models and methods to predict the onset velocity, pulsation frequency and amplitude and is based on actual field measurements on a number of different platforms and on research performed in collaboration with multiple operators and universities. Relevant inputs include the riser carcass geometry, operating conditions and the reflective characteristics of the topside and subsea piping.
One critical parameters is the liquid content. The phenomenon is mainly observed in dry gas systems. At even low liquid fractions, corrugated risers are less prone to generate pulsations. A number of laboratory experiments have been performed to evaluate the singing suppression at different liquid loads for both horizontal as well as vertical (upward) flow. Finally, a field trial was executed by Statoil at an FPSO in the Norwegian Sea. One export riser showed singing tendencies. Due to the vibrations, a reduced production limit was set. A field measurement campaign was started to inject liquid into the export risers to provisionally increase production, while in the meantime permanent solutions were evaluated and installed.
The mechanisms playing a role when liquid is present in corrugated pipe are reviewed in this paper: the cavities are (possibly partially) filled-up by the liquid, the boundary layers are modified by the added roughness of the wall, liquid droplets can interact with the acoustic waves. All these can reduce the source term and increase the acoustic losses in the pipe, therefore delaying or avoiding the singing.
Nuevos en foques en el estudio de los Monasterios Jerónimos Santa María de la Murta y San Lorenzo de El Escorial: organización funcional y tipologías
Authors: Chías Navarro Pilar , Sender Contell Marina 
Published: October 2015

En el estudio de la arquitectura monacal perteneciente a la Orden Jerónima encontramos conjuntos arquitectónicos muy deteriorados o en vías de ruina, como es el caso del Monasterio de Santa María de la Murta. Como sucede ante cualquier intervención en el patrimonio, es necesario un conocimiento previo y exhaustivo del edificio y de su historia a todos los niveles, que no sólo incluyen aspectos formales y constructivos, sino otros como funcionales y tipológicos que requieren considerar tanto cuestiones relativas al diseño y uso de los espacios, como las propias normas monásticas de la Orden, de influencia decisiva en su proceso de configuración. En este sentido, muchos de los vacíos históricos que las ruinas ya no nos permiten documentar pueden llenarse por comparación con otros monasterios mejor conservados, como es el caso del Monasterio del Escorial. El presente estudio propone un análisis sobre unas arquitecturas históricas que conduzca a la reflexión sobre la arquitectura de nuestro tiempo.
Making and Unmaking Bodies: Academic Women in Art Education
Authors: Ward Amber 
Published: October 2015

Abstract
The 2014 suspension of an art education program at State University, a research institution in the Midwest, leads the author’s journey into exploring truths. The exploration begins with biographical artifacts from her academic ancestry at the University. Specifically, the author uses Foucault’s genealogical analysis of descent to investigate visually 10 portrait photographs and two biographies that traverse the 20th century. The visual analysis reveals the ways in which truths both make and unmake the bodies of women academic art teachers at State University. Ultimately, she learns that truths cannot totally imprint bodies without also rendering parts of those truths obsolete. This research also exposes how discourse and the material are marginalized through creative analysis. The concluding discussion challenges art educators to investigate the practices that "disrupt or sustain relations of power and advance knowledge" (Jackson & Mazzei, 2012, p. 57) so that they can continue pushing art education forward in the 21st century.
Antioxidant Activity and Validation of Quantification Method for Lycopene Extracted from Tomato
Authors: Cefali Letícia Caramori , Cazedey Edith Cristina Laignier , Souza-Moreira Tatiana Maria , Correa Marcos Antônio , Salgado Hérida Regina Nunes , Isaac Vera Lucia Borges 
Published: October 2015

Abstract
Lycopene is a carotenoid found in tomatoes with potent antioxidant activity. The aim of the study was to obtain an extract containing lycopene from four types of tomatoes, validate a quantification method for the extracts by HPLC, and assess its antioxidant activity. Results revealed that the tomatoes analyzed contained lycopene and antioxidant activity. Salad tomato presented the highest concentration of this carotenoid and antioxidant activity. The quantification method exhibited linearity with a correlation coefficient of 0.9992. Tests for the assessment of precision, accuracy, and robustness achieved coefficients with variation of less than 5%. The LOD and LOQ were 0.0012 and 0.0039 μg/mL, respectively. Salad tomato can be used as a source of lycopene for the development of topical formulations, and based on performed tests, the chosen method for the identification and quantification of lycopene was considered to be linear, precise, exact, selective, and robust.