bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of Waterflooding and Solvent Injection on the Solvent Vapour Extraction (VAPEX) Heavy Oil Recovery
Authors: Derakhshanfar M. , Jia X. , Jiang T. , Zeng F. , Gu Y. 
Published: December 2011

Abstract
Solvent vapour extraction (VAPEX) process is an economically viable, technically sound, and environmentally friendly in-situ heavy oil recovery method to exploit tremendous heavy oil and bitumen reserves. In this recovery process, significant heavy oil viscosity reduction is achieved through sufficient solvent dissolution and possible asphaltene precipitation. Over the past two decades, several researchers have carefully studied the effects of some major factors on the VAPEX process, such as the test pressure, reservoir porosity and permeability, solvent and heavy oil types, well configuration, and connate water saturation. However, it is unclear how waterflooding and solvent injection will affect a typical VAPEX process.
In this paper, waterflooding and solvent injection effects are experimentally studied by using a visual rectangular sand-packed high-pressure VAPEX physical model with a low permeability. The physical model is packed and then saturated with a heavy oil sample at the connate water saturation. Pure propane and a mixture of n-butane and methane are used as respective solvents to extract two different heavy oil samples. The waterflooding effect is examined by performing a series of VAPEX tests with the initial waterflooding, prior to the subsequent solvent injection/soaking. In addition to the visual observation of the solvent chamber evolution, the heavy oil production rate, produced solvent–oil ratio, and asphaltene content of the produced heavy oil are measured during the waterflooding and solvent injection/soaking. It is found that the initial waterflooding causes an oil production reduction in the subsequent solvent injection. Also solvent breakthrough occurs earlier and a small amount of water is produced afterwards. This is because the initial waterflooding creates some low-resistance channels for the injected solvent to bypass the untouched heavy oil. As a result, the heavy oil is not diluted enough to be produced during the subsequent solvent injection/soaking. In the absence of waterflooding, however, solvent injection alone can increase the heavy oil production in comparison with the solvent-soaking process. Moreover, it is visually observed that solvent injection leads to less asphaltene deposition onto the porous media. This is quantitatively verified by a higher measured asphaltene content of the produced heavy oil at a higher solvent injection rate.
Informing Our Elders About Dialysis
Authors: Schmidt Rebecca J. 
Published: December 2011

Summary
As the fastest growing sector of the incident ESRD population, older patients constitute a group for which renal replacement therapy has special implications. Older CKD patients have unique needs by virtue of advanced age, high prevalence of comorbid conditions, slower progression of renal disease, and reduced survival. Burdens and risks attendant to dialysis may be amplified in the older patient and patients with impaired functional status or comorbid conditions, and therefore, dialysis may confer little to no survival benefit. Rates of dialysis withdrawal are highest among the oldest patients, raising the possibility that the standard content of informed consent for dialysis warrants an age-sensitive approach that is attuned to the very different balance of pros and cons of dialysis for older patients with multiple comorbidities and younger patients with limited comorbidity. Informed consent for older patients should include presentation of risks, benefits, and burdens associated with dialysis, age-specific estimates of prognosis with and without dialysis, and potential for loss of independence and decline in functional status with initiation of dialysis. In this article, medical evidence and clinical practice guidelines relevant to advance care planning for the older patient with CKD are reviewed, issues to consider in the dialogue with older patients contemplating dialysis are presented, and recommendations for an age-attuned approach to informed consent for older CKD patients are made.
Accounting Restatements and the Timeliness of Disclosures
Authors: Badertscher Brad A. , Burks Jeffrey J. 
Published: December 2011

SYNOPSIS
Regulators are concerned that during the process of restating financial statements, firms fail to provide timely progress updates, and delay earnings announcements and regulatory filings. To reduce these perceived lags in disclosure, an advisory group to the Securities and Exchange Commission recommends more use of catch-up adjustments rather than restatements to correct accounting errors. Some investor groups oppose the recommendations because they fear that preparers will begin to correct important errors through catch-up adjustments, which are less transparent than restatements.
We inform this debate by examining (1) the length of disclosure lags around restatements to understand the extent of the problem, and (2) the causes of disclosure lags to evaluate whether the reforms would address the root causes of the lags. We find that lengthy lags are uncommon and appear to be largely unavoidable consequences of fraud investigations. When fraud is a factor, the firm typically takes weeks or months to release restatement details, quarterly earnings, and SEC filings, likely because investigations are necessary to restore the firm's ability to produce reliable information. When fraud is not a factor, the firm typically discloses the restatement's earnings impact within a day of the initial restatement announcement, and delays the quarterly earnings announcement and SEC filing by less than a week. Although fraud is by far the most economically significant cause of lags, we also find that lags increase when a restatement involves multiple, long-standing, or large errors. Finally, we show that the restatements targeted by the reforms tend to have the shortest lags, even among non-fraudulent restatements. Thus, the proposed reforms would have a negligible effect on disclosure timeliness because the targeted restatements tend to have short lags to begin with, and because long lags appear to be caused by inherent constraints on producing reliable information.
JEL Classifications: M41, G38.
Data Availability: Data are available from sources identified in the paper.
Perceptions and Misperceptions Regarding the Unqualified Auditor's Report by Financial Statement Preparers, Users, and Auditors
Authors: Gray Glen L. , Turner Jerry L. , Coram Paul J. , Mock Theodore J. 
Published: December 2011

SYNOPSIS
U.S. and international auditing standard setters continue to raise questions about standard auditors' reports and are exploring alternatives to those reports. Government agencies and professional organizations are also raising questions about the auditor's report. These questions point to a continued existence of an “audit expectation gap.” To investigate perceptions and misperceptions regarding the auditor's report, we conducted focus groups with five different stakeholder groups—financial statement preparers (CFOs), users (bankers, analysts, and non-professional investors), and external auditors. This approach allows detailed comparisons between the perceptions of the different stakeholder groups affected by the auditor's report. Findings include that financial statement users value the audit, but do not read the entire auditor's report. It is not clear to users, preparers, and auditors what the auditor's report is intended to communicate or the level of assurance being provided by the report. Stakeholders offered numerous suggestions to improve the auditor's report, but they also recognize those suggestions could significantly change the auditor's risk profile and increase audit fees. We suggest future research to determine if potential changes to the auditor's report would change users' behavior and if any resulting benefits outweigh the additional risks and costs.
Pulmonary Arterial Hypertension in Systemic Sclerosis Is Associated with Profound Impairment of Microvascular Endothelium-dependent Vasodilatation
Authors: HOFSTEE HERMAN M.A. , VOSKUYL ALEXANDRE E. , VONK NOORDEGRAAF ANTON , SMULDERS YVO M. , POSTMUS PIET E. , DIJKMANS BEN A.C. , SERNÉ ERIK H. 
Published: December 2011

Objective.Impaired microvascular function may contribute to organ complications in patients with systemic sclerosis (SSc). We investigated whether SSc patients with and without pulmonary arterial hypertension (PAH) show a graded impairment of microvascular function compared to healthy controls.Methods.Twenty-two patients with SSc and 22 controls were studied. All patients underwent right heart catheterization; 6 had no PAH (SSc-nonPAH) and 16 had PAH (SSc-PAH). Acetylcholine (ACh)-mediated endothelium-dependent vasodilatation and sodium nitroprusside (SNP)-mediated endothelium-independent vasodilatation were assessed by iontophoresis combined with laser Doppler flowmetry.Results.Compared to sex- and age-matched controls, ACh-mediated vasodilatation was reduced in SSc-PAH (340.4% vs 79.5%, respectively; p < 0.01), but not in SSc-nonPAH (340.4% vs 397.9%; p = 0.90). No significant differences were present between the groups in SNP-mediated vasodilatation.Conclusion.Systemic microvascular endothelium-dependent vasodilatation is markedly reduced in SSc complicated by PAH.
Effectiveness of Rituximab in Patients with Rheumatoid Arthritis: Observational Study from the British Society for Rheumatology Biologics Register
Authors: SOLIMAN MOETAZA M. , HYRICH KIMME L. , LUNT MARK , WATSON KATH D. , SYMMONS DEBORAH P.M. , ASHCROFT DARREN M. ,   the British Society for Rheumatology Biologics Register
Published: December 2011

Objective.To assess the effectiveness of rituximab (RTX) in patients with rheumatoid arthritis (RA) in routine clinical practice, and to identify predictors of 6-month response to RTX in patients for whom at least 1 anti-tumor necrosis factor-α (anti-TNF) therapy has failed.Method.The analysis involved 646 patients with RA registered with the British Society for Rheumatology Biologics Register (BSRBR) who were starting RTX and were followed for at least 6 months. Change in the 28-joint Disease Activity Score (DAS28), European League Against Rheumatism (EULAR) response, and proportions of patients achieving disease remission were used to assess the clinical response 6 months after starting RTX. Regression analyses were used to identify factors associated with the response in the patients for whom anti-TNF therapy had not worked. The models included baseline demographics, disease characteristics, baseline Health Assessment Questionnaire (HAQ), and drug history including biologic history.Results.The mean DAS28 at baseline was 6.2 (95% CI 6.1, 6.3), which decreased significantly to 4.8 (95% CI 4.7, 4.9) at the 6-month followup. Seventeen percent of the patients were EULAR good responders and 43% were moderate responders. Eight percent of the patients achieved disease remission. Subjects with higher baseline DAS28 score and those with positive rheumatoid factor (RF) status were significantly associated with a decrease in their DAS28 score (improvement), while women and patients with higher baseline HAQ score were less likely to improve.Conclusion.RTX has proven to be effective in routine clinical practice. When anti-TNF therapy fails, response to RTX was influenced by baseline DAS28 score, RF status, baseline HAQ score, and sex.
Integrated Methodology for Mapping and Monitoring Permafrost and Seasonally Frozen Ground
Authors: Walter G.R. , Stothoff S.A. , Necsoiu D.M. , Dinwiddie C.L. 
Published: December 2011

Abstract
Arctic regions have been determined to be particularly sensitive to a warming global climate both on the basis of climatic modeling and observation of dramatic changes in arctic landscapes and sea ice. As early as the 1990s, air temperatures in interior northwest Alaska were warming at a rate of 0.75 °C per decade. The resulting thawing of permafrost causes significant damage to buildings, roadways, and can lead to increased mass wasting (e.g., active layer detachments and thaw slumps) by melting the soil ice that " cements?? the grains together to resist soil movement, as well as ground subsidence. These climate-induced ground movements can threaten infrastructure, such as road, bridges, and pipelines, either by direct physical damage or indirectly, such as through changes in drainage patterns, increased risk of flooding and forest fires.
Because these geohazards often occur in remote locations with harsh weather conditions and limited access, and the precursor conditions for initiating them can occur gradually, methods for remotely monitoring changes in ground conditions and estimating ground failure risks have significant engineering and economic value. The research described in this paper addresses this need by developing techniques for detecting changes in permafrost and seasonally frozen soil terrains using satellite and airborne remote sensing data, and combining these data with mathematical models to estimate the risk of ground failures due to soil thawing. The methodology consists of combining multiple sources of satellite-acquired synthetic aperture radar (SAR) data with high resolution optical-band data and aerial photography to map frozen ground and associated changes in soil moisture, and to detect vertical and lateral ground movements.
The remote sensing data interpretations along with traditional soil and vegetation mapping are used to inform mathematical models of permafrost and frozen soil stability. These models are used to develop maps of the probability of ground movements associated with permafrost degradation and seasonally frozen soil under current and future climate conditions. The models and slope stability risk algorithm were applied to a portion of Kobuk Valley National Park, Alaska for which soil and vegetation land cover maps were available. The cryosphere model results suggest that the same relative change in active-layer thickness occurs across the landscape, but warmer locations experience a larger absolute change in active-layer thickness and may experience permafrost loss as a consequence. The slope failure risk algorithm indicates that the upland areas are most susceptible to slope failure, particularly south-facing slopes, but low-cohesion low-land soils and steep river banks are also susceptible to failure.
Wave Propagation at Marginal Ice Zone
Authors: Petrie F. , Rousse B. , Cholley J.M. 
Published: December 2011

Abstract
Moving in Artic and Sub-Artic regions imposes significant challenges on engineering aspects of offshore Oil & Gas fields development. These new developments have to be subjected to environment composed of level ice sheets, ice ridges, marginal ice zones and free sea.
Marginal ice zone means the transition between the free sea (no ice) and ice. It is accepted that waves damp out in heavy pack ice, but the relationship between the amount of wave damping with ice concentration and distance into the ice field is not fully understood, area requiring further research and development.
This paper presents the main results of the program "wave propagation in marginal ice zone" initiated through a French JIP in 2009. It identifies the state of practices and state of art on wave propagation at marginal ice zone. A comparison is presented between ice floe modelling technique, experimental results and theoretical values. Finally the wave tank experiments carried out in the BGO First basin are presented in detail for this program.

Introduction
The continuous interest of Total E&P and the engineering companies (Saipem, Technip, Doris, Entrepose) for the Artic and Sub-Artic regions has lead them to begin a R&D study on the topic "wave propagation at marginal ice zone" through a French JIP (ref 1). The objective of this JIP is to analyse wave propagation at marginal ice zone by means of model tests in BGO FIRST.
Firstly, this paper presents an overview of the knowledge on the marginal ice zone and the wave propagation. This preparatory work has lead to a reflection on the way to perform model tests to study the phenomena.
In addition, a number of challenges are developed in relation to the definition of the model tests, the physical model of ice floes, the selection of the parameters to be tested, their range, and the reliability of the experimentation performed in a limited space basin.
This paper will present the model tests setup and the test procedure, including the ice floe modelling and instrumentation. At the end, the results of the experimentation are presented and compared with some analytical calculations.
Ice Actions in ISO 19906 - Overview
Authors: Karna T. , Frederking R. , Shkhinek K. 
Published: December 2011

Abstract
Eighteen ice experts from nine countries were actively involved in the development of new guidelines for ice actions that are an essential part of the new standard ISO 19906. This paper provides an overview of the methods that are recommended for ice action determination.
This standard is based on the limit states design method. Therefore, guidelines are provided for ice actions in four different categories of limit states. Characteristic values of ice actions depend on the limit state concerned and also on the life-safety and consequence categories that are applicable to a structure.
As a general principle, design shall be carried out separately for global ice actions, local ice actions and for dynamic ice actions. Operational procedures may be used to reduce ice actions. Ice action scenarios need to be selected by taking account of the specific conditions in the ice regime for which a structure is designed.
Data from full scale measurements on instrumented structures were the basis for developing methods for calculating ice actions. These methods are recommended for the practical determination of design ice actions on offshore structures. Both probabilistic and deterministic methods can be used. For many action scenarios, it is useful to consider limit-stress, limit-energy and limit-force mechanisms as well as specific ice failure modes. ISO 19906 provides a variety of methods and formulas that consider these limiting mechanisms and ice failure modes for the determination of global ice actions. Three methods for determining local ice actions in different conditions are provided. Basic modes of dynamic ice actions are described and simple models are provided for vertical and conical structures.

1. Introduction
Several surveys of predicted ice actions have been carried out in recent years (Shkhinek et al. (1994); Croasdale (1994) and Timco and Croasdale (2006)). International experts were invited in these surveys to determine ice actions for a few basic scenarios. These studies have revealed little consensus and a wide spread in the predicted values of ice actions. This situation has been a good reason for the development of the new standard ISO 19906, which should significantly reduce the discrepancies in the prediction of ice actions.
The new guidelines of ice action determination are provided in the sub-clauses 8.2 and A.8.2 of the new standard. These clauses were written by an international group of eighteen experts from nine countries, as shown in Table 1. The resulting clause is the consensus of these experts.
It is well known that formulas on ice action can not be derived directly from first principles. Empirical factors that are obtained from experiments play a very central role in all ice load prediction. The new standard emphasizes the importance of full-scale data.
Arctic and Harsh Environment Pipeline Trenching Technologies and Challenges
Authors: Jukes Paul , Kenny Shawn , Panapitiya Upali , Jafri Syed , Eltaher Ayman 
Published: December 2011

Abstract
A primary challenge of Arctic and harsh environment offshore field development is the protection of subsea pipelines and flowlines on the seabed. Damage from ice either through direct contact or through soil movements/pressures acting on the pipeline from ice gouging is a serious risk. Trenching and burial of pipelines in Arctic and harsh environments such as the Beaufort Sea, Chukchi Sea and the Grand Banks are considered to be the primary means of preventing damage from ice. Trenching can provide adequate protection for pipelines in Arctic areas. This paper presents the challenges associated with trenching and burial of pipelines and flowlines in Arctic and harsh environments, and discusses the state-of-the-art trenching and dredging technologies. Future equipment developments required to meet functional specifications for working in Arctic and harsh environments is then presented. Furthermore, key areas surrounding the operability of trenching and associated equipment are also discussed. This paper shows that there are a number of challenges facing trenching pipelines in arctic regions, and there are limitations of current trenching and dredging equipments. A continued effort is required by the industry to overcome a number of key issues and challenges and promote productions in Arctic and harsh environment frontiers.

Introduction
The world demand for oil and gas is growing at an ever increasing rate and, as a result, there is a demand to explore new areas for more petroleum production. The arctic region is one of the remaining unexplored areas where such exploration still can be undertaken. According to the US Geological Survey estimates, the arctic region, mostly offshore, holds as much as 22% of the world's untapped reserve of hydrocarbons where much of the reserve is lying under seasonal or year-round sea ice. The exploitation of these remaining reserves, however, will depend upon meeting the technical challenges of design, construction, and operation of offshore installations. These general Arctic technical challenges have been previously presented [1].