bluuebunny/crossref_metadata_2025_split huggingface dataset:
Field Development Study: Channel Fracturing Achieves Both Operational and Productivity Goals in the Barnett Shale
Authors: Samuelson M. , Stefanski J. , Downie R. , Mikhaylov A. , Ovsyannikov D. , Peña A. 
Published: June 2012

Abstract
The Barnett shale has an extensive history of various hydraulic fracture methodologies aimed at creating both reservoir connection via complex fracture networks and a conductive proppant pack for fluid flow to the wellbore. Multiple studies indicate that effective stimulation of shale plays like the Barnett shale require extensive conductive complex fracture development coupled with sufficient proppant-pack retained permeability to maximize well productivity. Studies have also shown that wells very often underperform expectations after the application of low proppant concentrations with slickwater fluids and/or hybrid designs with linear or crosslinked fluids. Furthermore, recent increased restrictions on fracturing operations in urban areas have created a need to reduce the operational footprint of the treatments without compromising production results. The need exists for novel stimulation methods capable of addressing these challenges.
The channel hydraulic fracturing technique creates open pathways within the proppant pack by combining specific surface equipment controls and pumping protocols with fluid and fiber technologies. The engineered network of channels provides highly conductive paths for the flow of fluids from the reservoir to the wellbore.
We conducted a study including more than 50 treatments performed in the Barnett shale with this technique. These treatments reduced proppant and water used per well up to 40% and 36%, respectively, compared to treatments with conventional methods in offset wells. The study includes the use of advanced modeling software, coupled with microseismic evaluation and comparison of conventional job designs with the channel-fracturing approach, to evaluate the impact on fracture geometry.
The results of the study indicate that the channel fracturing technique increased operational efficiency at equivalent well production in the study area of the Barnett shale. Microseismic comparisons show similar fracture heights and transverse fracture lengths. Coupling of conventional higher rate slickwater treatments with the channel fracturing technique yields equivalent well production while achieving significant reductions in fluid and proppant used in the job designs. The project demonstrated that such reductions have led to more than 38 million gallons of water and over 3,000 proppant and water-hauling trips saved for every 50 stages using this technology for the stimulation of wells in the Barnett shale.
A Pore Scale Gas Flow Model for Shale Gas Reservoir
Authors: Swami Vivek , Settari A. (Tony) 
Published: June 2012

Abstract
It has been observed that the shale gas production modeled with conventional simulators/models is much lower than actually observed field data. Generally reservoir and/or stimulated reservoir volume (SRV) parameters are modified (without much physical support) to match production data. One of the important parameters controlling flow is the effective permeability of the intact shale. In this project we aim to model flow in shale nano pores by capturing the physics behind the actual process. For the flow dynamics, in addition to Darcy flow, the effects of slippage at the boundary of pores and Knudsen diffusion have been included. For the gas source, the compressed gas stored in pore spaces, gas adsorbed at pore walls and gas diffusing from the kerogen have been considered. To imitate the actual scenario, real gas has been considered to model the flow. Partial differential equations were derived capturing the physics and finite difference method was used to solve the coupled differential equations numerically. The contribution of Knudsen diffusion and gas slippage, gas desorption and gas diffusion from kerogen to total production was studied in detail. It was seen that including the additional physics causes significant differences in pressure gradients and increases cumulative production. We conclude that the above effects should be considered while modeling and making production forecasts for shale gas reservoirs.
Effect of Capillary Relaxation on Water Entrapment after Hydraulic Fracturing Stimulation
Authors: Michel G. , Sigal R. , Civan F. , Devegowda D. 
Published: June 2012

Abstract
Effect of retardation in fluid displacement on transport inside capillary tubes during leak-off and clean-up for hydraulically stimulated reservoirs is investigated by modeling of the relevant phenomena. The effect of wall proximity during the transport in narrow capillaries is formulated. The importance of the critical properties alteration due to confinement is demonstrated by modification of the real gas deviation factor. The relaxation in fluid displacement observed in the fluid transport dynamics is coupled with the bundle of tubes representation of porous media for investigation of the relaxation effects on fluid saturation, capillary pressure, and relative permeability. An analytical formulation of the relaxation time corresponding to water removal during clean-up processes following hydraulic fracture stimulation is presented. The dynamics of advancement of the wetting and non-wetting fluids inside capillary tubes are illustrated by various applications.
Resolving Audit Engagement Challenges through Communication
Authors: Bobek Donna D. , Daugherty Brian E. , Radtke Robin R. 
Published: June 2012

SUMMARY
This paper investigates the successful resolution of audit challenges faced by auditing professionals. We use an experiential questionnaire (EQ) (Gibbins and Qu 2005) to elicit practicing auditors' experiences with resolving challenges personally encountered on an audit engagement. One hundred ninety-seven auditing professionals from all levels (staff to partners) and firm types (local to Big 4) responded to our EQ, and 130 provided complete information about a self-identified challenge they had encountered. Over 70 percent of these challenges were successfully resolved wherein communication with other auditors on the engagement, along with communication with the client, aided most in the resolution process. These results provide evidence confirming theory-based research indicating the importance of knowledge sharing for CPAs (Vera-Muñoz et al. 2006). Our findings also extend prior research on the components of professional judgment (Gibbins and Emby 1985; Emby and Gibbins 1988; Gibbins and Mason 1988) by providing insight into the potentially troublesome area of challenges that are often encountered during an audit, and how effective communication can lead to successful resolution of such challenges.
Effect of ovarian activity on orthodontic tooth movement and gingival crevicular fluid levels of interleukin-1β and prostaglandin E2 in cats
Authors: Celebi Ahmet Arif , Demirer Serhat , Catalbas Bulent , Arikan Sevket 
Published: June 2012

AbstractObjective:To evaluate whether there is any correlation between ovarian activity and two potent bone-resorbing mediators (prostaglandin E2 [PGE2], interleukin-1β [IL-1β]) secreted from the gingival crevicular fluid (GCF) during orthodontic tooth movement.Materials and Methods:Eighteen female cats were included in this study. Animals were randomly divided into three groups (estrous, anestrous, and ovariectomized groups), each having six queens. Estrous was induced by administration of 150 IU equine chorionic gonadotropin (eCG) to queens of the estrous group. A closed-coil spring, applied with 80 g of tipping force to the canine, was attached between the maxillary canine and mini-implant. GCF was collected on days 0, 6, and 12 from each cat to examine PGE2 and IL-1β during orthodontic tooth movement in cats. The PGE2 and IL-1β levels were determined with enzyme-linked immunosorbent assay.Results:There was no significant difference (P &gt; .05) between anestrous and the ovariectomized groups in terms of tooth movement on days 6 and 12 of distalization. In contrast, tooth movement in the estrous group was lower (P &lt; .05) than in the remaining two groups (anestrous and ovariectomized). The mean PGE2 and IL-1β levels of the canine teeth of the estrous groups were significantly lower than the remaining two groups on days 6 and 12 (P &lt; .05) of coil spring applications.Conclusions:These results indicate that ovarian activity can affect orthodontic tooth movement and GCF levels of IL-1β and PGE2 in cats.
The Relationship Between Brain Volume and Walking Outcomes in Older Adults With and Without Diabetic Peripheral Neuropathy
Authors: Manor Brad , Newton Elizabeth , Abduljalil Amir , Novak Vera 
Published: June 2012

OBJECTIVE
Diabetic peripheral neuropathy (DPN) alters walking. Yet, the compensatory role of central locomotor circuits remains unclear. We hypothesized that walking outcomes would be more closely related to regional gray matter volumes in older adults with DPN as compared with nonneuropathic diabetic patients and nondiabetic control subjects.

RESEARCH DESIGN AND METHODS
Clinically important outcomes of walking (i.e., speed, stride duration variability, and double support time) were measured in 29 patients with DPN (type 2 diabetes with foot-sole somatosensory impairment), 68 diabetic (DM) patients (type 2 diabetes with intact foot-sole sensation), and 89 control subjects. Global and regional gray matter volumes were calculated from 3 Tesla magnetic resonance imaging.

RESULTS
DPN subjects walked more slowly (P = 0.005) with greater stride duration variability (P &lt; 0.001) and longer double support (P &lt; 0.001) as compared with DM and control subjects. Diabetes was associated with less cerebellar gray matter volume (P &lt; 0.001), but global gray matter volume was similar between groups. DPN subjects with lower gray matter volume globally (P &lt; 0.004) and regionally (i.e., cerebellum, right-hemisphere dorsolateral prefrontal cortex, basal ganglia, P &lt; 0.005) walked more slowly with greater stride duration variability and/or longer double support. Each relationship was stronger in DPN than DM subjects. In control subjects, brain volumes did not relate to walking patterns.

CONCLUSIONS
Strong relationships between brain volumes and walking outcomes were observed in the DPN group and to a lesser extent the DM group, but not in control subjects. Individuals with DPN may be more dependent upon supraspinal elements of the motor control system to regulate several walking outcomes linked to poor health in elderly adults.
Alterations of the Hsp70/Hsp90 chaperone and the HOP/CHIP co-chaperone system in cancer
Authors: Ruckova Eva , Muller Petr , Nenutil Rudolf , Vojtesek Borivoj 
Published: June 2012

AbstractActivation of the Hsp90 chaperone system is a characteristic of cancer cells. The regulation of chaperone activities involves their interaction with cochaperones; therefore we investigated the expression of Hsp70 and Hsp90 and their specific co-chaperones HOP and CHIP in cancer cell lines and primary cancers. Inhibition of Hsp90 by 17AAG increased the levels of Hsp70, Hsp90 and HOP but not CHIP mRNA in cancer cells. These changes are linked to activation of the HSF1 transcription factor and we show that the HOP promoter contains HSF1 binding sites, and that HSF1 binding to the HOP promoter is increased following 17AAG. The lack of alteration in the co-chaperone CHIP is explained by a lack of HSF response elements in the CHIP promoter. Non-proliferating cells expressed higher levels of CHIP and lower HOP, Hsp70 and Hsp90 levels compared to proliferating cells. Decreased expression of CHIP in proliferating cancer cells is in keeping with its proposed tumor suppressor properties, while over-expression of HOP in proliferating cells may contribute to excessive Hsp90 activity and stabilization of client proteins in tumors. In a panel of colorectal cancer samples, increased expression of Hsp70 and an increased ratio of HOP to CHIP were found, and were associated with decreased median survival. These data indicate that multiple changes occur in the chaperone/co-chaperone system in cancer that impact patient survival. It is likely that the ability to identify individual alterations to this system will be beneficial for treatment strategy decisions, particularly those that employ chaperone inhibitors.
Angiogenin and vascular endothelial growth factor expression in lungs of lung cancer patients
Authors: Rozman Ales , Silar Mira , Kosnik Mitja 
Published: June 2012

Background. Lung cancer is the leading cause of cancer deaths. Angiogenesis is crucial process in cancer growth and progression. This prospective study evaluated expression of two central regulatory molecules: angiogenin and vascular endothelial growth factor (VEGF) in patients with lung cancer.
Patients and methods. Clinical data, blood samples and broncho-alveolar lavage (BAL) from 23 patients with primary lung carcinoma were collected. BAL fluid was taken from part of the lung with malignancy, and from corresponding healthy side of the lung. VEGF and angiogenin concentrations were analysed by an enzyme-linked immunosorbent assay. Dilution of bronchial secretions in the BAL fluid was calculated from urea concentration ratio between serum and BAL fluid.
Results. We found no statistical correlation between angiogenin concentrations in serum and in bronchial secretions from both parts of the lung. VEGF concentrations were greater in bronchial secretions in the affected side of the lung than on healthy side. Both concentrations were greater than serum VEGF concentration. VEGF concentration in serum was in positive correlation with tumour size (p = 0,003) and with metastatic stage of disease (p = 0,041). There was correlation between VEGF and angiogenin concentrations in bronchial secretions from healthy side of the lung and between VEGF and angiogenin concentrations in bronchial secretions from part of the lung with malignancy.
Conclusion. Angiogenin and VEGF concentrations in systemic, background and local samples of patients with lung cancer are affected by different mechanisms. Pro-angiogenic activity of lung cancer has an important influence on the levels of angiogenin and VEGF.
Ultrasound elastography as an objective diagnostic measurement tool for lymphoedema of the treated breast in breast cancer patients following breast conserving surgery and radiotherapy
Authors: Adriaenssens Nele , Belsack Dries , Buyl Ronald , Ruggiero Leonardo , Breucq Catherine , De Mey Johan , Lievens Pierre , Lamote Jan 
Published: June 2012

Background. Lymphoedema of the operated and irradiated breast is a common complication following early breast cancer treatment. There is no consensus on objective diagnostic criteria and standard measurement tools. This study investigates the use of ultrasound elastography as an objective quantitative measurement tool for the diagnosis of parenchymal breast oedema.
Patients and methods. The elasticity ratio of the subcutis, measured with ultrasound elastography, was compared with high-frequency ultrasound parameters and subjective symptoms in twenty patients, bilaterally, prior to and following breast conserving surgery and breast irradiation.
Results. Elasticity ratio of the subcutis of the operated breast following radiation therapy increased in 88.9% of patients, was significantly higher than prior to surgery, unlike the non operated breast and significantly higher than the non operated breast, unlike preoperative results. These results were significantly correlated with visibility of the echogenic line, measured with high-frequency ultrasound. Big preoperative bra cup size was a significant risk factor for the development of breast oedema.
Conclusions. Ultrasound elastography is an objective quantitative measurement tool for the diagnosis of parenchymal breast oedema, in combination with other objective diagnostic criteria. Further research with longer follow-up and more patients is necessary to confirm our findings.
Demographic processes in rural areas of Belarus: geographical structure and spatial dynamics
Authors: Antipova Ekaterina , Fakeyeva Liudmila 
Published: June 2012

Demographic processes in rural areas of Belarus: geographical structure and spatial dynamics
The study presents the spatiotemporal regularities and shifts in geo-demographic development of rural areas of Belarus at the multiscale level. Trends in rural population size dynamics for the period of 1959-2009 are detected and characterised. In accordance with the trends in the dynamics of the rural population of Belarus spatial regularities were identified. The geo-demographic territory of Belarus is typified on character of demographic dynamics and natural movement processes of rural population. We have identified three types of districts by the nature of the rural population dynamics for the period of 1970-2009: stable, growing and shrinking; and three types of natural population movement dynamics for the same period in accordance with spatial and temporal heterogeneity of the rural depopulation.
Socio-economic potential of Polish cities - a regional dimension
Authors: Bogdański Marcin 
Published: June 2012

Socio-economic potential of Polish cities - a regional dimension
The main aim of the research presented in this paper was to construct and evaluate a synthetic index of socio-economic potential of Polish cities (IoEp) at the level of voivodships and also to examine relations between this potential and the economic development of regions. The index reflects the level of localisation advantages offered by a city. That is why an assumption was made that there is a positive relationship between the level of socio-economic potential of cities in a region (measured by the IoEP index) and its level of economic development. The obtained results show that there are significant and stable differences in the level of economic potential of Polish cities. One can also observe that the higher the level of IoEP was, the higher the value of regional GDP per capita. That gives some basis to positively verify the research hypothesis.
Socio-economic transformation of small towns in East Germany after 1990 - Colditz case study
Authors: Cudny Waldemar 
Published: June 2012

Socio-economic transformation of small towns in East Germany after 1990 - Colditz case study
The article presents the main demographic and social, as well as functional and spatial changes that took place in Colditz after 1990. The town is inhabited by 4,870 people (2009) and is situated in Saxony, in the area of the former German Democratic Republic (GDR). The aim of the article is to present the main changes, which took place there after East and West Germany reunited in 1990. The author describes demographic and social changes in the population size, population growth, migration balance, unemployment, and other elements of urban community. Moreover, the article presents the changes in the economic-functional structure, such as de-industrialisation, succession of urban functions, and tourism development, as well as the main spatial changes in Colditz, such as architectural revitalisation and reconstruction of urban infrastructure. In the conclusions, the author briefly presents potential directions in the future development of the town.
Urbanisation and changes in fertility pattern in Poland and in the selected countries of Western and Southern Europe
Authors: Kurek Sławomir , Lange Milena 
Published: June 2012

Urbanisation and changes in fertility pattern in Poland and in the selected countries of Western and Southern EuropeSince the beginning of the 1990s profound changes have occurred in reproductive behaviour in Central and Eastern Europe. They involve a sudden fall in the fertility rate, accompanied by an increase in the age of mothers giving birth to their first child, and a growth in the percentage of extramarital births. A similar course of changes in reproductive behaviour was observed almost a decade earlier in the countries of Southern Europe (Greece, Spain and Italy), and at the beginning of the 1960s in the countries of Western Europe (e.g. France). The aim of the study is to show the spatial changes in the fertility pattern in Poland compared to the selected European countries - Italy, Spain and France. Since new fertility patterns take hold most quickly among the inhabitants of large cities, as a result of the weaker effects of tradition and earlier formation of social norms owing to suburbanisation processes, the analysis of changes in reproductive behaviours will be conducted in the context of changes in urbanisation level. The time frame of the study encompasses an extended duration, especially taking into account the period of 1970-2010. For the comparison of large cities, data from 2010 or the nearest available were examined.
The efficiency of polycentric development strategies in the context of economic crisis. Case study - the development of Southwest Oltenia region - Romania
Authors: Peptenatu Daniel , Pintilii Radu , Draghici Cristian , Peptenatu Alina 
Published: June 2012

The efficiency of polycentric development strategies in the context of economic crisis. Case study - the development of Southwest Oltenia region - RomaniaRomania's polycentric development model was elaborated by the Interdisciplinary Centre for Advanced Researches on Territorial Dynamics within the University of Bucharest and by Urbanproiect SA. The elaboration of the polycentric development strategy is based on the human settlements' classification depending on their polarisation capacity and the designing of a polycentric network, able to ensure the territorial complexity necessary to the attenuation of negative impulses from the suprasystems' level. The world economic crisis may be considered the most powerful negative impulse after the Second World War, generating major disfunctionalities at the level of fragile territorial systems. The elaboration of some specific strategies, able to take into account the new challenges given by the global world, is an important preoccupation of the decision factors in order to increase territorial competitiveness.
Correlation of bio- and magnetostratigraphy of Badenian sequences from western and northern Hungary
Authors: Selmeczi Ildikó , Lantos Miklós , Bohn-Havas Margit , Nagymarosy András , Szegő Éva 
Published: June 2012

Correlation of bio- and magnetostratigraphy of Badenian sequences from western and northern HungaryLithological, magnetostratigraphic and paleontological (nannoplankton, foraminifers, molluscs) studies were carried out on the Badenian successions of boreholes Sopron-89, Nagylózs-1 and Sáta-75 in Hungary. The correlations with the ATNTS2004 scale show that the Badenian sedimentation began during Chron C5Br thus the earliest Badenian deposits are missing in the sections. The first occurrence ofOrbulina suturalisBrönnimann has been observed in Subchron C5Bn.1r, at 14.9 Ma. Although it is older than the interpolated age of 14.74 Ma in Chron C5ADr in the ATNTS2004, it is consistent with the age of 15.1 Ma obtained from recent calibration of planktonic foraminiferal bioevents. The base of the Bulimina-Bolivina Zone has been determined at 13.7 Ma in Chron C5ABr, and the Badenian/Sarmatian boundary is recorded within Chron C5AAn, at 13.15 Ma.