bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluating the Impact of Fracture Proppant Tonnage on Well Performances in Eagle Ford Play Using the Data of Last 3-4 Years
Authors: Gao Chao , Du C. Mike
Published: October 2012

Since 2008, horizontal wells completed with multi-stage hydraulic fracturing have dramatically boosted Eagle Ford production. Due to high drilling and completion costs, operators have been trying to improve development economics by optimizing the stimulation treatments. This paper presents a look-back analysis on the stimulation treatments performed by different Eagle Ford operators from 2008-2012 using data mining methodologies, focusing on how proppant tonnage has impacted early-time production of their Eagle Ford wells. The Eagle Ford wells have been observed having high decline rates and the early time production performance evaluation will be critical in project economics evaluations and EUR forecasts. The results of this look-back analysis may be used for field development optimization, where to drill and how much proppant should be pumped in each of different areas of Eagle Ford play.

The focus of this paper is to present how proppant tonnage could impact the early time production performance. However, there are many variables affecting the early time performance of Eagle Ford wells. In this paper, we present data using bubble maps, contour maps, grid maps and scatter plots to show how some major geological and reservoir engineering variables could affect the early time performance of the Eagle Ford wells. The wells with similarities are grouped in order to minimize the variation of geological variables and other engineering variables and to derive consistent correlations between proppant tonnage and early time performances in different well groups. We present data in different well groups to show the correlations between proppant tonnage and early time well performance.

For this study, the authors built a database of 3000+ Eagle Ford wells (including 2300+ horizontals). The authors found that it was very challenging to clean the public data and reformat it to a presentable manner.
Assessment of Artificial Lifts for Oil Wells in Egypt
Authors: Ghareeb M. , Ellaithy W. F. , Zahran I. F.
Published: October 2012

One of the challenges facing the Egyptian oil industry is to increase production and maximize reserves especially in mature and marginal fields.

The fast and continuous development in artificial lift technology plays a role in solving these problems. Recent improvements in technology, automation and metallurgy have reduced lifting costs through system components that resist hostile environments, optimize power usage, and improve reliability allowing profitable production from previously uneconomic fields or wells.

Since the oil industry first emerged in Egypt, over 200 oil and gas fields have come on-stream. Natural producing wells represent less than 9% of this total; other wells are lifted artificially.

This paper will present the history, present day, and the future application of artificial lift systems in Egyptian oil fields, covering the main problems encountered in the operation of each single system of artificial lift including the actions taken to overcome or eliminate these problems. Special emphasis will be given to marginal and mature oil fields because of the economical limitations accompanied with development costs.
Vector Field Based Fault Modelling and Stratigraphic Horizons Deformation
Authors: Bouziat Antoine
Published: October 2012

Consequent choices during hydrocarbon exploration and field developement depend on 3D numerical models of the main geological interfaces and the major faults in the area of interest. Such structural models provide decisive informations like reservoir rock volume or compartmentalization, and are unavoidable stages to build the reservoir grids used for resources estimation, flow simulations and well planning. However, these models need to be continually modified, either to integrate new information from well drilling and production history or to consider several hypotheses about the most uncertain features of the fault network. To do so, petroleum engineers involved in reservoir modeling need flexible and efficient tools to easily edit parts of structural models while preserving their general consistency.

In a first step to handle structural model edition challenges, we propose a new way to numerically model a fault object and deform previously modelled stratigraphic horizons. This method is inspired by the "Vector Field based Shape Deformations" (VFSD ) techniques used by the Computer Graphics community. Our approach considers a fault as a 3D vector field, interpolated thanks to several scalar fields linked to the fault geometry and few scattered data points if available. This vector field is then integrated into path lines able to drive the deformation of the surrounding objects in a purely geometrical manner. The so-obtained deformation is limited to an influence region neighboring the fault and can affect several horizons simultaneously in a consistent and reversible way. Moreover, self-intersections can be prevented and both the first order smoothness and the fine-scale features of the deformed horizons are conserved.

The vector field interpolation methodology we present is based on a user-defined conceptual model for deformation attenuation and a direction constraint on the displacement. It was implemented in common geomodelling software. The resulting tool is applicable on a wide range of fault geometries, and can be added as a new exit condition for fault network stochastic simulation algorithms. Last, some derived applications, related to salt diapir modelling or paleotopography restoration, are also conceivable.
Application of Nanotechnology on Borehole Wall Stability in Gas-Liquid Medium Transition during Gas Drilling
Authors: Xu Zichen
Published: October 2012

Gas drilling has many advantages such as high drilling speed, low damage to reservoir and avoiding circulation lose, etc. However, when gas drilling encounters geological risks, drilling fluid must be filled, which may lead to serious borehole wall collapse. These problems severely restrict the application of gas-drilling technology. Thus, this paper puts forward using nano technology to reverse the wetting characteristics of borehole-wall surrounding rock before filling water based drilling fluid into the well. In this way, the capillary effect can prevent further penetration of drilling fluid, and avoid the swelling of shale and propagating of fractures on the surrounding rock. The strength of the borehole wall can be improved by taking advantage of this technology. The author puts forward that the application of the high-speed gas current to atomize the solution. The atomized solution will carry nano wetting reverse agent and anti-swelling agent rise with gas along borehole wall. Instead of the previous research method from perspective of drilling fluid, this technology can directly change the surface character of fracture surface with small amount of treating agent to avoid the propagating of fractures. Besides, the technique can effectively reduce the friction of the drill string and the impact of the drill string on the borehole wall. The technology is expected to achieve the goal of keeping the wellbore stability in gas liquid medium transition during gas drilling process.
Oil Shale Technology and Efficient Utilization of Oil Shale Resources in Egypt
Authors: Khaled Mohamed Shafik
Published: October 2012

In The Name of God the Merciful

The availability of energy resources is of paramount importance to society. The greatest challenge facing the energy sector today is how to meet the rising demand for energy and on the other hand, the depletion of crude oil resources. To solve this dilemma, greater efforts should be devoted to develop alternative energy resources such as oil shale as a supplement of conventional oil supplies.

However combinations of high oil prices, improved extraction technologies and increasing energy depend have reignited interest oil shale industry.

Oil shale is a rock that contains kerogen, an organic substance that breaks down when heated to yield combustible liquids, gases, and solids. The liquid product – crude shale oil can be transformed into a replacement for conventional crude. Shale oil is expensive to produce, and it has never been able to compete with conventional crude for very long time. However, crude prices have risen in the past few years and are expected to stay high which could make oil shale development practical. The quality of oil shale is either expressed by its heating value or the amount of shale oil that can derived from it liter/ton. Oil shale is considered commercial for use if its quality from 100 – 200 liter/ton.

Processes for producing shale oil generally fall into one of two groups: mining followed by surface retorting and in-situ retorting.

In this paper we try to study the strategic significance of oil shale development in Egypt from many aspects (economic profit – employment benefits – socioeconomic).

On the other hand there are critical issues with oil shale project, I try to suggest practical solutions that can help to reduce the severity of these critical issues and improve shale oil production cost.
Fluid Flow and Heat Transfer in the Top Hat Oil Recovery System
Authors: Mathews Kyle J.
Published: October 2012

In 2010, as part of the remediation efforts surrounding the Deepwater Horizon drilling rig incident, also known as the Macondo incident, multiple containment and collection systems were deployed in an attempt to capture as much oil as possible, as well as minimizing the amount of oil released into the Gulf of Mexico. The Top Hat was one of the recovery systems implemented to collect oil. In a Top Hat recovery system, oil is produced up the tubing and hot water is injected down an annulus (riser and drill pipe—two concentric pipes are required) to prevent the onset of hydrate formation. Recovery data of collected oil was readily accessible [10]. However, no data was available concerning the temperature and flowrate of the injected water. A coupled model of fluid flow and heat transfer was developed to estimate the hot water injection temperature and flow rate needed to keep the oil warm enough to avoid hydrate formation.

Existing well production data was extensively analyzed to determine the fluid flow and heat transfer of the oil produced through the tubing in the riser. The fluid flow analysis of the production data, coupled with the surrounding seawater pressure and temperature distribution, was used to model the flow and heat transfer of the injected water in the Top Hat recovery system. Two cases were studied in detail—the first assumed a riser made up of uninsulated steel, and the second assumed a steel riser with an outer insulation sheath. The goal was to maintain a water injection temperature high enough to agree with the production data, as well as to maintain a pressure versus temperature distribution outside the hydrate forming region. The flow rate, injection temperature and injection pressure of the hot water are the desired parameters. In order to approximate the operating conditions of the collection system, a coupled model of fluid flow and heat transfer was developed.
Laboratory study of Fracturing Fluid Migration due to Spontaneous Imbibition in Fractured Tight Formations
Authors: Dutta Riteja
Published: October 2012

During hydraulic fracturing operations in low permeability formations, spontaneous imbibition of fracturing fluid into the rock matrix may be responsible for having a significant impact on the retention of water-based fracturing fluids in the neighborhood of the induced fracture. This may consequently affect the post-frac productivity of the well. However, there is lack of direct quantitative and visual evidence of the extent of retention, evolution of the resulting imbibing fluid front, and how they relate to potential productivity hindrance. In this paper, laboratory experiments have been carefully designed to represent the vicinity of a hydraulic fracture. The evolution of fracturing fluid leak-off is monitored as a function of space and time using X-ray computed tomography (CT). The X-ray CT imaging technique allows us to map saturations at controlled time intervals to monitor the migration of fracturing fluid into the reservoir formation. It is generally expected for low permeability formations to show strong capillary forces due to their small characteristic pore radii, but this driving mechanism is in competition with the low permeability and spatial heterogeneities found in tight gas sands. The relevance of capillarity as a driver of fluid migration and retention in a tight gas sand sample is interpreted visually, quantified and compared with high permeability Berea sandstone in our experiments. It is seen that although these formations demonstrate strong capillarity, the effect can be suppressed by the low permeability of the formation and the heterogeneous nature of the sample. However, saturation values attained during imbibition experiments are comparable to those previously obtained for high permeability samples, which can have significant implications in terms of phase mobilities in the neighborhood of induced fractures. Results from this investigation are expected to provide fundamental insight regarding critical variables affecting the retention and migration of water-based fracturing fluids in the neighborhood of hydraulic fractures, and consequently on the post-frac productivity of the well.
Experimental Investigation of Formation Damage Reduction: Mud Cake Removal and Mud Filtration Treatment using Ultrasonic Wave Radiation
Authors: Vakilinia Bahador
Published: October 2012

Interactions of reservoir with drilling and completion fluids, mud cake and mud filtration, lead to formation permeability damages which result in reduction of production rate. For increasing the production rate and treating the formation damage, normally Matrix Acidizing and Hydraulic Fracturing treatment are used. Although hydraulic fracturing and matrix acidizing are effective operations, they have some critical issues. For instance, they need some specialized fluids that require the petroleum industry to spend over millions of dollars per year for this treatment.

Applications of ultrasonic waves have been widely developed in petroleum processes due to its significant positive effects. In this study, wellbore stimulation using ultrasonic wave radiation has been experimentally investigated. The experiment is categorized in two steps: At first, the effect of sonication on mud cake removal has been studied and next, the effect of ultrasonic wave on mud filtration treatment has been surveyed. Glass beads ranging from 70 to 100 mesh sizes were packed as the porous media and three kinds of water based mud in different weights were used as the samples for making the damage on glass bead pack to simulate the reservoir formation damage. Various ultrasonic wave intensities have been examined with different radiation times in order to find the optimum radiation time. The results show that at early time of ultrasonic exposing for mud filtration treatment, the permeability decreases by pervading the mud filtration in porous media while at the late time it increases, which shows that ultrasonic radiation removed mud cake form porous media and improved permeability. Finally, an optimum time obtained and it has been proved that ultrasonic radiation can increases the permeability of damaged zone.
New Guidelines Document Assists With PRMS Applications
Authors: Lee W. John , Purewal Satinder , Harrell D. Ronald
Published: October 2012

Continuing their leadership in developing consistent, clear, and reliable practices and guidance for international use in reserves reporting, SPE and sister organizations (AAPG, WPC, SPEE, and SEG) issued in November 2011 a new document entitled Guidelines for Application of the Petroleum Resources Management System (AG) to accompany and support PRMS. The AG updates the 2001 document Guidelines for the Evaluation of Petroleum Reserves and Resources, also published by SPE, which was issued prior to adoption of PRMS by three of these major professional organizations. This new document will assist reserves evaluators throughout the world in understanding PRMS and how it should be applied in financial, regulatory, and reporting activities. Two new chapters (on deterministic reserves estimation and on unconventional resources) have been added to the AG; eight others have been updated; and a comprehensive glossary entitled "Reference Terms" has been added.

The AG is available free to the public (not just to SPE members) on the SPE website. In addition, the SPE Oil and Gas Reserves Committee (OGRC) has begun to conduct Advanced Technology Workshops throughout the world. These workshops are intended to provide opportunities to discuss the AG and to present and discuss regional examples of PRMS applications.
A Semi-Analytic Solution for Flow in Finite-Conductivity Vertical Fractures Using Fractal Theory
Authors: Cossio Manuel
Published: October 2012

The exploitation of unconventional reservoirs goes hand in hand with the practice of hydraulic fracturing and, with an ever increasing demand in energy, this practice is set to experience significant growth in the coming years. Sophisticated analytic models are needed to accurately describe fluid flow in a hydraulic fracture and the problem has been approached from different directions in the past 3 decades, starting with the work of Gringarten et al. (1974) for an infinite conductivity case, followed by contributions from Cinco et al. (1978), Lee and Brockenbrough (1986), Ozkan and Raghavan (1991) and Blasingame and Poe (1993) for a finite-conductivity case. This topic is still an active area of research and, for the more complicated physical scenarios such as multiple transverse fractures in ultra-tight reservoirs, answers are presently being sought.

Starting with the seminal work of Chang and Yortsos (1990), fractal theory has been successfully applied to pressure transient testing, albeit with an emphasis on the effects of natural fractures in pressure-rate behavior. In this paper, we begin by performing a rigorous analytical and numerical study of the Fractal Diffusivity Equation and show that it is more fundamental than the classic linear and radial diffusivity equations. Subsequently, we combine the Fractal Diffusivity Equation with the trilinear flow model (Lee and Brockenbrough 1986), culminating in a new semi-analytic solution for flow in a finite-conductivity vertical fracture which we name the "Fractal Fracture Solution". This new solution is very fast and its accuracy is comparable to that of the Blasingame and Poe solution (1993). In its final, closed form, it is valid for a dimensionless fracture conductivity FcD ≥ 3. Ultimately, this project is a demonstration of the untapped potential of fractal theory; our approach is very flexible and we are optimistic about extending the same methodology to develop new solutions for pressing problems that the industry currently faces, the only caveat being that it must calibrated to a known solution or production history.
Microbial Biomass for Improving Sweep Efficiency in Fractured Carbonate Reservoir Using Date Molasses as Renewable Feed Substrate
Authors: Al-Hattali R.
Published: October 2012

Selective plugging by microbial biomass is one of the proposed mechanisms for improving reservoir sweep efficiency in highly fractured reservoirs. In this study, the potential of Bacillus licheniformis strains isolated from oil contaminated soil from the Sultanate of Oman was tested for their ability to grow in induced fractures in carbonate rocks and to divert subsequent injection water to the unswept matrix zones.

Three B. licheniformis strains were tested: B17, B29 and W16. Their ability to grow in minimal media with Omani date molasses as the sole carbon source was investigated. Two different concentrations of date molasses (3% & 8% w/v) were tested. It was found that the higher concentration of molasses gave higher growth rate for all strains.

The combination of B. licheniformis strain W16 in a minimal medium containing 3% molasses was the optimum condition for maximum cell growth within 18 hours of incubation. Standard Indiana limestone core plugs were used for coreflooding experiments where a fracture was induced by slicing the cores vertically into two sections using a thin blade. The bacterial cells were injected into the cores and the ability of the microbes to grow and plug the fracture was examined.

Coreflooding experiments showed promising results where enhancement of oil recovery was observed after bacterial injection. A total of 28.57% of the residual oil was produced after 18 hours of incubation. The results showed the high potential of using date molasses as the carbon source for microbial biomass production for selective plugging in fractured reservoirs.
Spirituality as a Lived Experience: Exploring the Essence of Spirituality for Women in Late Life
Authors: Manning Lydia K.
Published: October 2012

Against the backdrop of a dramatic increase in the number of individuals living longer, particularly older women, it is vital that researchers explore the intersection of spirituality, gender, and aging. In this qualitative study of six women aged 80 and older, I explore, using, multiple, in-depth interviews, the experiences of spirituality over the life course. A hermeneutic phenomenological analysis of the interviews was performed and provided insights into the nature of their “lived experience” allowing for the understanding of the essence of their spirituality. The results are presented as an interpretation of the participants' perceptions of their spirituality and spiritual experiences. For the women in this study, the essence of their spirituality lies in: being profoundly grateful; engaging in complete acceptance; and having a strong sense of assuredness, while stressing the linkages and importance of spirituality. Implications for understanding spirituality for older adults are considered.
Community Involvement, Perceived Control, and Attitudes toward Aging among Lesbians and Gay Men
Authors: Hostetler Andrew J.
Published: October 2012

A person-environment approach was used to explore the relationship between community involvement and attitudes toward aging among middle-age and older lesbians and gay men. Specifically, this study investigated the relationships between participation in gay community activities, perceived control, and aging-related concerns among two partially-overlapping convenience samples of middle-aged and older lesbians and gay men ( N = 136). As expected, perceived control was negatively associated with aging concerns, while community involvement was surprisingly positively associated with the latter. Although the hypothesized interaction between control and community participation was not supported, exploratory analysis revealed an interaction between participation and a measure of autonomy in the single men sample. Specifically, the combination of high autonomy and low community participation was associated with the lowest levels of aging-related concern. Findings are discussed with respect to the implications of having aging-related concerns, the limitations of both control and community, and different possible pathways to positive aging.
Faith Schools: Democracy, Human Rights and Social Cohesion
Authors: Grace Gerald
Published: October 2012

This article argues that faith-based schools are a necessary feature of democratic and pluralistic societies and a legitimate expression of human rights as constituted in the European Convention in Human Rights (2000). It further argues that if the rights of parents to have a real choice for faith-based schools (regardless of ability to pay) are to be actualised, then state funding for such schools is required. The article concludes by saying that current arguments that faith-based schools are generative of social or community conflict have no basis in existing empirical research. These arguments, when examined, are not evidence based but rather based upon polemical and prejudiced assertions which give a superficial reading of the causes of community conflict, as in the case of Northern Ireland.
Catholic Schools and Sectarianism in Scotland: Educational Places and the Production and Negotiation of Urban Space
Authors: Flint John
Published: October 2012

This article explores the role of state-funded Catholic schools in debates about the causes and manifestations of sectarianism in Scotland. It suggests that debates between proponents and opponents of state-funded Catholic schools (and indeed faith schools more generally) have been largely aspatial, focusing on the teaching ethos within schools - empirically weak conceptions of the impacts of segregated schooling on social networks, and abstract national-level accounts of religion, ethnicity, identity and belonging. The article argues for a focus upon the productive power of schools as place nodes within a network of urban spaces and the agency of pupils in identity and friendship construction. It suggests the need to recognise the specifics of the social, spatial and political national and local contexts within which faith schools are situated. It concludes with an examination of educational policy responses to sectarianism in Scotland, arguing that they have focused on disrupting the spatial ordering of faith schools in an attempt to realign the physical boundaries of segregation and the visibility of difference in urban space.
Faith Schools and the Plural Society: Exploring Notions of Diversity in School Provision in England
Authors: Morris Andrew B.
Published: October 2012

Around thirty per cent of all schools in England have a religious character. The author argues that the current ‘faith schools debate’ is more about the nature of its ‘plural society’ than about the place of such schools within the state-maintained sector. He suggests that to assume we are, in fact, living within a determinedly plural society is not as clear-cut as one might suppose, and that the very existence of the current ‘faith school debate’ in England is an indication that we are not as committed to pluralism as we might like to think. First he sets out two differing conceptions of the plural society - one strong, one weak. Then he sketches the historical and legislative backdrop to the present English state-maintained educational system. His third objective is to chart, briefly, the development of the educational system since the 1980s and to describe how it corresponds to changes from a strong to a weak concept of a plural society in which societal attitudes which once championed legislation supporting minority communities now seem to be leaning towards marginalising or even suppressing the contribution of such groups to the common good. Finally, he argues that the continuing existence of a distinctive dual system of educational provision in England, of which the Catholic sector is a paradigm, provides a bulwark against a creeping tide of weak pluralism, which has been likened to a form of damaging totalitarianism.
Sharing Classes between Separate Schools: A Mechanism for Improving Inter-Group Relations in Northern Ireland?
Authors: Hughes Joanne , Lolliot Simon , Hewstone Miles , Schmid Katharina , Carlisle Karen
Published: October 2012

One manifestation of division and the history of conflict in Northern Ireland is the parallel education system that exists for Protestants and Catholics. Although recent decades have seen some advances in the promotion of integrated education, around 95% of children continue to attend schools separated on ethno-religious lines. In 2007 a programme for sharing education was established. Underpinned by intergroup contact theory, and reflecting educational priorities shared by all school sectors, the programme seeks to offer children from different denominational schools an opportunity to engage with each other on a sustained basis. In this article the authors adopt a quantitative approach to examining the impact of participation in the Sharing Education Programme on a range of outcomes (out-group attitudes, positive action tendencies and out-group trust) via, first, intergroup contact (cross-group friendships) and, second, intergroup anxiety. Their findings confirm the value of contact as a mechanism for promoting more harmonious relationships, and affirm the Sharing Education Programme as an initiative that can help promote social cohesion in a society that remains deeply divided.
Defending Identity and Ethos: An Analysis of Teacher Perceptions of School Collaboration in Northern Ireland
Authors: Donnelly Caitlin
Published: October 2012

The purpose of this article is to examine the process of collaborative working between teachers located in separate faith-based schools in Northern Ireland. Drawing on theories of intergroup relations, and with reference to in-depth interviews with teachers in post-primary schools, the article shows that despite earlier research which identified a reluctance amongst teachers in the different sectors to work together, most Catholic and Protestant teachers are motivated to collaborate to develop a more broadly based curriculum for pupils. However, it has also been shown that teachers tend to studiously avoid discussing their differences in mixed-faith contexts, and it is argued that this may have the potential to constrain collaborative relations. It is concluded that without strategic direction from policy makers to assist teachers in negotiating and exploring their differences it will be difficult to build the trust which is likely to sustain collaborative relations.
Teachers' ‘Contact’ at the Integrated Bilingual Schools in Israel
Authors: Bekerman Zvi
Published: October 2012

This article is about teachers working at the bilingual integrated schools in Israel. The study allows us to problematise and critically approach cross-cultural encounters on the basis of contact theory, which posits understandings regarding social interaction across cultural-political boundaries. It exposes potential differences between the outcomes of educational-initiated contact (as the ones initiated for students in the schools) and contact as this occurs in more natural/real settings, such as the workplace (in our case, the school setting as the workplace of the teachers). In the ‘real’ life of the integrated schools, teachers are learning something about the need to accommodate ideological issues to achieve some practical gains. They seem to grasp in some way that ideology sets the human condition upside down, as in a camera obscura. It is as if real-life situations and their practices put the real as a limit to the ideological and set the school in a journey whose end we do not know and which may surprise us. The arguments presented are an attempt to move towards a better understanding of the complexities of the construction and crossing of social borders as well as the practices which might be open to transaction/ negotiation in social encounters and those which might not.
Anger and Political Culture: A Time for Outrage!
Authors: Peters Michael A.
Published: October 2012

This article examines the role of political anger in democracy. It reviews the work of Stéphane Hessel before examining the role and reception of anger in classical and modern thought. The author identifies two main traditions within which the concept of political anger can be located: revolutionary violence of the Marxist tradition and the peaceful, nonviolent tradition of civil disobedience initiated by Gandhi. The culture of anger going back to the ancients is examined, followed by a review of the ‘angry young men’ culture of a group of authors around John Osborne and his famous play Look Back in Anger. The author insists that the culture of political anger is an essential set of readings, techniques and skills that are indispensable in the neoliberal age.
Audit Partner Perceptions of Post-Audit Review Mechanisms: An Examination of Internal Quality Reviews and PCAOB Inspections
Authors: Houston Richard W. , Stefaniak Chad M.
Published: October 2012

SYNOPSIS

This study reports the results of a survey of 107 audit partners from large public accounting firms that investigates and compares partner perceptions of Public Company Accounting Oversight Board (PCAOB) inspections' and Internal Quality Reviews (IQRs): (1) predictability, (2) conduct, (3) reviewer qualifications and behavior, and (4) effects (i.e., on audits, partners, and firms). A majority of partners can or try to predict the year of both reviews and perceive that, relative to PCAOB inspections, IQR reviewers have a better understanding of firms' audit methodologies, IQRs focus more on whether firms follow their methodology, and IQRs examine more audit areas. In addition, partners believe that PCAOB inspectors are more focused on finding deficiencies than are IQR reviewers, and that IQR feedback is more timely and helpful for improving audit quality. Both reviews are perceived to impact professional reputation; however, partners perceive that PCAOB inspections increase their firms' litigation risk more so than do IQRs. Finally, less experienced partners perceive reviews as more invasive and as posing more consequences than do more experienced partners. We provide credible, informed perceptions of partners directly involved in both PCAOB inspections and IQRs (which heretofore have not been examined directly by practitioner or academic research) that should be beneficial to accounting researchers, practicing auditors, and regulatory bodies interested in understanding the perceived effects and effectiveness of PCAOB inspections and IQRs.
The effect of acetylcholine on Characeae K+ channels at rest and during action potential generation
Authors: Kisnieriene Vilma , Ditchenko Tatiana , Kudryashov Anatoly , Sakalauskas Vidmantas , Yurin Vladimir , Ruksenas Osvaldas
Published: October 2012

The role of acetylcholine (ACh) as a signalling molecule in plants was investigated using a model system of Characeae cells. The effect of ACh on conductance of K+ channels in Nitella flexilis cells and on the action potential generation in Nitellopsis obtusa cells after H+-ATPase inhibition, where repolarization occurs after the opening of outward rectifying K+ channels, was investigated. Voltage-clamp method based on only one electrode impalement was used to evaluate the activity of separate potassium ion transport system at rest. We found that ACh at high concentrations (1 mM and 5 mM) activates K+ channels as the main membrane transport system at the resting state involved in electrogenesis of Characeaen membrane potential. We observed that ACh caused an increase in duration of AP repolarization of cells in K+ state when plasmalemma electrical characteristics are determined by large conductance K+ channels irrespective of whether AP were spontaneous or electrically evoked. These results indicate interference of ACh with electrical cellular signalling pathway in plants.
Gender-based differences in the effect of dietary cholesterol in rats
Authors: Marounek Milan , Volek Zdeněk , Skřivanová Eva , Czauderna Marian
Published: October 2012

Male and female rats were fed diets supplemented with cholesterol and palm fat at 10 and 50 g/kg, respectively; serum, hepatic tissue and faeces were analysed. Cholesterol supplementation significantly increased serum and hepatic cholesterol both in male and female rats. Male and female rats fed the cholesterol-containing diet differed significantly in serum cholesterol concentration (2.48 µmol/mL vs 2.92 µmol/mL), concentration of serum triacylglycerols, but not in hepatic cholesterol concentration. The serum and hepatic cholesterol concentrations correlated non-significantly in male rats (r=0.491; P=0.063) and significantly in female rats (r=0.818; P<0.001). Cholesterol supplementation non-significantly decreased relative expression of the hepatic LDL receptor gene and significantly increased relative expression of the hepatic cholesterol 7α-hydroxylase gene in rats of both genders. The faeces of control rats contained similar amounts of cholesterol and bile acids. Cholesterol supplementation increased cholesterol concentration 10 times in the faeces of male rats and 12 times in faeces of female rats. The corresponding increases of bile acid concentration were much lower (83% in male rats and 108% in female rats). It can be concluded that the effects of cholesterol supplementation were more pronounced in female than in male rats.
On complete pseudo-BL-algebras. A Cantor-Bernstein type theorem
Authors: Walendziak Andrzej , Wojciechowska-Rysiawa Magdalena
Published: October 2012

Pseudo-BL-algebras are a noncommutative extention of BL-algebras. In this paper we consider polars in pseudo-BL-algebras and the class of complete pseudo-BL-algebras. In the final section, a version of the Cantor-Bernstein theorem will be proved.
On BO-algebras
Authors: Kim Chang , Kim Hee
Published: October 2012

In this paper, we introduce the notion of a BO-algebra, and we prove that every BO-algebra is 0-commutative, and we show that BO-algebras, 0-commutative B-algebras, BM-algebras, p-semisimple BCI-algebras and abelian groups are logically equivalent.
Tying up baric algebras
Authors: Oller-Marcén Antonio
Published: October 2012

Given two baric algebras (A
1, ω
1) and (A
2, ω
2) we describe a way to define a new baric algebra structure over the vector space A
1 ⊕ A
2, which we shall denote (A
1 ⋈ A
2, ω
1 ⋈ ω
2). We present some easy properties of this construction and we show that in the commutative and unital case it preserves indecomposability. Algebras of the form A
1 ⋈ A
2 in the associative, coutable-dimensional, zero-characteristic case are classified.
Convergence rates in the complete moment of moving-average processes
Authors: Zang Qing-pei
Published: October 2012

In this paper, we discuss precise asymptotics for a new kind of moment convergence of the moving-average process $$X_k = \sum\limits_{i = - \infty }^\infty {a_{i + k} \varepsilon _i }$$, k ≥1, where {ε
i: −∞ < i < ∞} is a doubly infinite sequence of independent identically distributed random variables with mean zero and the finiteness of variance, {α
i: −∞ < i < ∞} is an absolutely summable sequence of real numbers, i.e., $$\sum\limits_{i = - \infty }^\infty {\left| {a_i } \right| < \infty }$$.
Asymptotic properties for the loglog laws under positive association
Authors: Yang Xiao-Rong , Fu Ke-Ang
Published: October 2012

Let {X
n: n ≥ 1} be a strictly stationary sequence of positively associated random variables with mean zero and finite variance. Set $$S_n = \sum\limits_{k = 1}^n {X_k }$$, $$Mn = \mathop {\max }\limits_{k \leqslant n} \left| {S_k } \right|$$, n ≥ 1. Suppose that $$0 < \sigma ^2 = EX_1^2 + 2\sum\limits_{k = 2}^\infty {EX_1 X_k < \infty }$$. In this paper, we prove that if E|X
1|2+δ
< for some δ ∈ (0, 1], and $$\sum\limits_{j = n + 1}^\infty {Cov\left( {X_1 ,X_j } \right) = O\left( {n^{ - \alpha } } \right)}$$ for some α > 1, then for any b > −1/2 $$\mathop {\lim }\limits_{\varepsilon \searrow 0} \varepsilon ^{2b + 1} \sum\limits_{n = 1}^\infty {\frac{{(\log \log n)^{b - 1/2} }}
{{n^{3/2} \log n}}} E\left\{ {M_n - \sigma \varepsilon \sqrt {2n\log \log n} } \right\}_ + = \frac{{2^{ - 1/2 - b} E\left| N \right|^{2(b + 1)} }}
{{(b + 1)(2b + 1)}}\sum\limits_{k = 0}^\infty {\frac{{( - 1)^k }}
{{(2k + 1)^{2(b + 1)} }}}$$ and $$\mathop {\lim }\limits_{\varepsilon \nearrow \infty } \varepsilon ^{ - 2(b + 1)} \sum\limits_{n = 1}^\infty {\frac{{(\log \log n)^b }}
{{n^{3/2} \log n}}E\left\{ {\sigma \varepsilon \sqrt {\frac{{\pi ^2 n}}
{{8\log \log n}}} - M_n } \right\}} _ + = \frac{{\Gamma (b + 1/2)}}
{{\sqrt 2 (b + 1)}}\sum\limits_{k = 0}^\infty {\frac{{( - 1)^k }}
{{(2k + 1)^{2b + 2} }}} ,$$ where x
+ = max{x, 0}, N is a standard normal random variable, and Γ(·) is a Gamma function.
Determining Predictor Importance in Hierarchical Linear Models Using Dominance Analysis
Authors: Luo Wen , Azen Razia
Published: October 2012

Dominance analysis (DA) is a method used to evaluate the relative importance of predictors that was originally proposed for linear regression models. This article proposes an extension of DA that allows researchers to determine the relative importance of predictors in hierarchical linear models (HLM). Commonly used measures of model adequacy in HLM (i.e., deviance, pseudo- R2, and proportional reduction in prediction error) were evaluated in terms of their appropriateness as measures of model adequacy for DA. Empirical examples were used to illustrate the procedures for comparing the relative importance of Level-1 predictors and Level-2 predictors in a person-in-group design. Finally, a simulation study was conducted to evaluate the performance of the proposed procedures and develop recommendations.
Alternative Multiple Imputation Inference for Mean and Covariance Structure Modeling
Authors: Lee Taehun , Cai Li
Published: October 2012

Model-based multiple imputation has become an indispensable method in the educational and behavioral sciences. Mean and covariance structure models are often fitted to multiply imputed data sets. However, the presence of multiple random imputations complicates model fit testing, which is an important aspect of mean and covariance structure modeling. Extending the logic developed by Yuan and Bentler, Cai, and Cai and Lee, we propose an alternative method for conducting multiple imputation–based inference for mean and covariance structure modeling. In addition to computational simplicity, our method naturally leads to an asymptotically chi-square model fit test statistic. Using simulations, we show that our new method is well calibrated, and we illustrate it with analyses of three real data sets. A SAS macro implementing this method is also provided.
Student Mobility, Dosage, and Principal Stratification in School-Based RCTs
Authors: Schochet Peter Z.
Published: October 2012

In school-based randomized control trials (RCTs), a common design is to follow student cohorts over time. For such designs, education researchers usually focus on the place-based (PB) impact parameter, which is estimated using data collected on all students enrolled in the study schools at each data collection point. A potential problem with this approach, however, is that the PB impact parameter could confound intervention effects on student mobility with more policy-relevant intervention effects on student achievement. Furthermore, the PB parameter pertains to students with different levels of intervention exposure, which complicates the interpretation of the impact findings. To address these issues, this article uses a principal stratification approach to examine the survivor average causal effect (SACE) parameter for original cohort students who would remain in their baseline study schools in either the treatment or control condition. The SACE parameter pertains to those who would receive maximum exposure to the intervention, and thus is a relevant parameter for dosage analyses. A strategy to estimate the SACE parameter is discussed using maximum likelihood (ML) methods for finite mixture models, the expectation-maximization (EM) algorithm, and robust standard errors to adjust for clustering. The estimation approach is demonstrated using data from a recent large-scale, school-based RCT where student mobility was common during the 3-year follow-up period.
Political globalization and the shift from adult education to lifelong learning
Authors: Milana Marcella
Published: October 2012

This article reflects on the shift in vocabulary from (adult and continuing) education to (lifelong) learning and the ideological and purposive orientations it carries. It does so by critically addressing the changes occurred in policy discourses concerned with the education of adults after WWII at transnational level. The main argument is that the shift in vocabulary has been favoured by an increased voice acquired by transnational and inter-states entities (i.e. OECD, UNESCO, EU) in educational matters, however in combination with a change in political emphasis, at least within the European Union, from creating jobs opportunities towards securing that citizens acquire marketable skills. While both trends seems to point at the demise of the nation state as a guarantor for social justice, more research is needed to deepen our understandings of the interplay between transnational and nation-state levels; thus the article concludes by suggesting a research agenda to move in this direction.
Discursive turns from 'Bildung' to managerialism
Authors: Filander Karin
Published: October 2012

The article focuses on the struggles over ethos in academic adult education tradition that grows from the frameworks of student generations in Finnish adult education. It brings together elements of present-day analysis and historically sensitizing memory data on generations of the 1960s, 1970s and 1980s. My interest here lies in how the rhetoric of lifelong learning and education has revised the basic assumptions of adult education. The data suggest that the dominant narrative of adult education is increasingly the discourse of marketization. Finnish present-day student generations seem to have lost their intrinsic connections with the Scandinavian traditions of popular enlightenment and the values of equality and basic logics enabling 'second chances' for all adult citizens within the Nordic welfare state. One of the results of the analysis was the following question: Should we reinvent adult education again from the standpoint of sustainable development of 'ordinary people'?
Automatic Joint Alignment Measurements in Pre- and Post-operative Long Leg Standing Radiographs
Authors: Weber G. M. , Dries S. P. M. , Gooßen A.
Published: October 2012

Objectives: For diagnosis or treatment assessment of knee joint osteoarthritis it is required to measure bone morphometry from radiographic images. We propose a method for automatic measurement of joint alignment from pre-operative as well as post-operative radiographs.

Methods: In a two step approach we first detect and segment any implants or other artificial objects within the image. We exploit physical characteristics and avoid prior shape information to cope with the vast amount of implant types. Subsequently, we exploit the implant delineations to adapt the initialization and adaptation phase of a dedicated bone segmentation scheme using deformable template models. Implant and bone contours are fused to derive the final joint segmentation and thus the alignment measurements.

Results: We evaluated our method on clinical long leg radiographs and compared both the initialization rate, corresponding to the number of images successfully processed by the proposed algorithm, and the accuracy of the alignment measurement. Ground truth has been generated by an experienced orthopedic surgeon. For comparison a second reader reevaluated the measurements. Experiments on two sets of 70 and 120 digital radiographs show that 92% of the joints could be processed automatically and the derived measurements of the automatic method are comparable to a human reader for pre-operative as well as post-operative images with a typical error of 0.7° and correlations of r = 0.82 to r = 0.99 with the ground truth.

Conclusions: The proposed method allows deriving objective measures of joint alignment from clinical radiographs. Its accuracy and precision are on par with a human reader for all evaluated measurements.