bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Creation and Annealing Kinetics of Fast Light Induced Defect States created by 1 Sun Illumination in a-Si:H
Authors: Albert M.L. , Deng J. , Niu X. , Pearce J.M. , Collins R.W. , Wronski C.R. 
Published: December 2012

AbstractPreliminary results are presented on the kinetics of fast states at 25°C created by 1 sun illumination in protocrystalline hydrogen diluted a-Si:H films. The results are for the bulk properties of the a-Si:H films which was confirmed by the similarity of results obtained on corresponding intrinsic layers in p-i-n solar cells. It is found that the kinetics exhibit two regimes. The first regime is in the form of a delay before the onset of an A·log(t) time dependence indicative of a dispersive process. Despite the unexpected effect of a dependence of this first regime on the degradation/annealing history of the samples, it was possible to characterize the highly reproducible logarithmic dependences for different illumination times as well as in the presence of different carrier generation/recombination rates. It is found that for the degradation times studied, the annealing kinetics associated with the second regime are independent of the 1 sun illumination time but are dependent on the recombination introduced by illuminations as low as ∼0-5 of 1 sun. These fast states are located close to midgap, similar to the position of dangling bond defects. The results presented raise interesting questions that still need to be answered about the nature and origin of the fast defects in order to assess their contribution to the long term degradation and the overall stability a-Si:H materials.
Advanced Characterization of the Electronic Structure of MEH-PPV
Authors: Chambers David Keith , Selmic Sandra 
Published: December 2012

AbstractIn this paper, we present research results that explore the basic molecular structure, orientation, and electrical properties of the conjugated polymer poly(2-methoxy-5- (2,9-ethyl-hexyloxy)-1,4-phenylenevinylene) (MEH-PPV). The bandgap structure of MEH-PPV was investigated through optical absorption and emission spectra, and ultraviolet photoemission spectroscopy (UPS). Based on the optical absorption of MEH-PPV, the π-π* bandgap energy is 2.14eV. The emission spectrum of ITO/MEH-PPV/Al light emitting diode has a peak at 590nm in wavelength which corresponds to photon energies of 2.1eV. By using ultraviolet synchrotron radiation to investigate the highest occupied molecular orbitals (HOMO) of the MEH-PPV, the relative change in photoemission cross-section for various electron states was measured. The HOMO to Fermi level gap obtained from UPS spectra is about 3eV. The UPS measurements include angle-resolved and incident energy dependent spectra. Some indication of bulk film orientation was inferred by dispersion of incident energy dependent UPS. Disparities in these spectra imply some role for defect states, extrinsic carrier involvement, or Fermi-level pinning.
Simplified Drilling Technique Does Not Decrease Dental Implant Osseointegration: A Preliminary Report
Authors: Jimbo Ryo , Giro Gabriela , Marin Charles , Granato Rodrigo , Suzuki Marcelo , Tovar Nick , Lilin Thomas , Janal Malvin , Coelho Paulo G. 
Published: December 2012

Background: To date, some experimental studies have addressed the effect of bone drilling technique and sequence on dental implant osseointegration. In the present study, the authors hypothesize that there would be no differences in osseointegration when reducing the number of drills for osteotomy compared to the conventional drilling protocols.Methods: Seventy‐two implants (diameters 3.75 mm and 4.2 mm; n = 36 for each diameter) were bilaterally placed in the tibia of 18 beagles for 1, 3, and 5 weeks. Half of the implants of each diameter were placed using a simplified drilling procedure (pilot and final drill), and the other half were placed using a conventional drilling procedure (all drills in sequence). The retrieved samples were subjected to histologic and histomorphometric evaluation.Results: Histology showed that new bone formed around the implant, and inflammation or bone resorption was not evident for both groups. Histomorphometrically, the simplified group presented significantly higher bone‐to‐implant contact and bone area fraction occupancy compared to the conventional group after 1 week; however, no differences were detected at 3 and 5 weeks.Conclusion: Bone responses to the implant with the simplified protocol can be comparable to the conventional protocol.
Underbalance Drilling of an Above Sea Level, Sub-Hydrostatic Reservoir; Recompenses – A Case History
Authors: Malik Saeed Aslam , Channa Munsif Hussain , Majeed Arshad , Latif Muhammad Khalid , Asrar Muhammad 
Published: December 2012

Abstract
During this period of energy crisis in Pakistan every effort is being made to produce every molecule of subsurface hydrocarbons. Particularly, the gas reservoirs which were not brought on production, due to low well deliverability or lack of required technology in the past are being explored and exploited. These include Tight, Low BTU, Sour and Acidic gas reservoirs. Such reservoirs pose specific problems related to drilling, production and development aspects.
This paper depicts drilling and testing of a reservoir which is above sea level and its initial reservoir pressure is approximately 1000 psi below the normal hydrostatic pressure. It is one of the lowest pressure reservoirs of the world which has been drilled with successful flow of gas. Underbalance drilling technology was chosen to drill this challenging reservoir. Primary objective of under balance Drilling (UBD) was to establish reservoir potential by acquiring virgin reservoir characteristics.
Historically, three wells have been drilled to test this reservoir. First two wells were drilled using conventional drilling methodology, both the wells experienced heavy mud loses during drilling and it was difficult to evaluate the production potential of this low pressure reservoir. Afterwards, pay zone of SML in third well × #02 was drilled and tested using Underbalance Drilling technique.
This paper further describes the problems faced by the operator to drill first two wells in terms of mud losses and evaluation of production potential of low pressure reservoir of SML. In conclusion, it was a successful application which happened due to exceptional team work from all project parties. This application has opened new horizons of exploration and production of such reservoirs particularly in Baluchistan and generally in Pakistan.
A Comprehensive Shale Gas Explooitation Sequence for Pakistan and Other Emerging Shale Plays
Authors: Haider Batool A. , Aizad Tanweer , Ayaz Syeda Areeba , Shoukry Ahmed 
Published: December 2012

Abstrct
The explosive growth of shale gas production in the US has sparked a global race to determine which other regions from around the world have the potential to replicate this success. One of the main areas offocus is the Asia Pacific region, specifically Pakistan.
In this paper, real results from seven different US shale basins-Marcellus, Eagle Ford, Haynesville, Barnett, Woodford (West-Central Oklahoma), Fayetteville and Bakken- have been used to develop a comprehensive sequence of shale exploitation strategy for emerging shale plays. The study involves integration of shale gas exploitation knowledge reinforced by a decade of experience across most of the North American shale gas basins, with published data. Different reservoir properties have been compared to develop a comprehensive logic of the effective techniques to produce from shale-gas reservoirs. We have validated the sequence with real results from US shale production ventures, published case histories, and by global experts who have been directly involved in shale reserves evaluation and production.
Subsequently, several different reservoir attributes of Pakistan shale plays have been compared with US basins, in an attempt to identify analogues.
It is the intent of this paper to diminish the difficult and often expensive learning cycle time associated with a commercially successful shale project, as well as to attempt to illustrate the most influential factors that determine optimum production. A very few papers in the petroleum literature that provide an extensive and systematic approach towards shale exploitation strategy for given shale-reservoir conditions
An Alternative Approach for Well Test Analysis and Production Performance in Tight Gas Reservoirs Considering Stress Dependent Permeability
Authors: Arif Muhammad , Bhatti Amanat Ali , Khan Ahmed Saeed , AfrazHaider Syed 
Published: December 2012

ABSTRACT
It has long been proved experimentally that the tight gas sands are more pronounced to stress changes as compared to moderate and high permeability reservoirs because of the narrow flow channels of the formation [1]. The consideration of the effect of stress in the evaluation and production performance of tight gas reservoirs is very important in order to make right decisions regarding their development. Due to hydrocarbon production, the effective stress increases causing a reduction in permeability and porosity of the porous medium.
The conventional pressure transient analysis techniques in gas wells based on constant permeability would become unreliable [2]. Consequently, the incorrect evaluation of permeability leads towards wrong decision regarding well stimulation. Also the inflow performance modeling of tight gas reservoirs based on constant permeability will not be corrected as far as evaluation of well's production potential is concerned.
Few studies on tight gas reservoirs considering the effect of stress sensitive permeability used the Raghavan's stress dependent pseudo-pressure approach [3] for which pressure vs. permeability data was determined experimentally. But, if laboratory data is not available then there is need to develop an analytical approach to generate the pressure vs. permeability data required for the use of stress dependent pseudo-pressure in reservoir evaluation and production performance studies in tight gas reservoirs.
The objective of this paper is to develop an analytical approach, in the absence of lab data, to generate pressure vs. permeability data for the determination of stress dependent pseudo-pressure. This stress dependent pseudo-pressure is used for well test analysis to determine the stress sensitive formation permeability and also to generate production performance in tight gas reservoirs. The developed technique has also been implemented on the field data of a tight gas reservoir tovalidate the results by using actual well's production history.
Asphaltene Prediction and Prevention: A Strategy to Control Asphaltene Precipitation
Authors: Buriro Muhammad Ali , Shuker Muhannad Talib 
Published: December 2012

ABSTRACT
Asphaltene Precipitation and Deposition is a serious problem which can reduce the oil recovery by reducing reservoir permeability and altering the wettability. It can plug wells and flow lines through deposition and also cause separation difficulties at the separation facilities. Taking preventive measures are always a wise solution rather than attempting to resolve issues when they are occurred.
This study proposes a strategy and provides the comprehensive review of the methodology required to predict and prevent Asphaltene Precipitation.
Light crude oil samples were taken to be characterized for their thermodynamic properties. The saturation pressure and Asphaltene Onset Point (AOP) were measured at different pressures, temperatures and compositional changes using the Solid Detection System (SDS). Phase diagram and Asphaltene Precipitation Envelopes (APE) were developed. Cubic Plus Association (CPA) equation of state was used to develop the Asphaltene phase envelope using Multiflash (infochem). Titration technique was used to obtain the Asphaltene Floculation point (AFP) using the dead oil and n-Heptane as a precipitant. Effect of different inhibitors was then evaluated using the Solid Detection System (SDS) equipment using the titration technique. Rock-Inhibitor Compatibility was then checked in the reservoir core samples by performing the dynamic core flooding test in the laboratory.
Conclusively, this strategy helps to enhance the reservoir performance by minimizing the asphaltene precipitation and will save the cost associated with the consequences of high asphaltene precipitation.
A New Life to the Abandoned and Suspended Wells of Middle Indus Basin
Authors: Amjad Muhammad , Mugheri Sikandar , Soomoro Moazim , Rosa Giuseppe De , Danilo Albani 
Published: December 2012

ABSTRACT
Widening supply and demand gap in natural gas industry, the advent of tight gas policy and increasing interest of operators in tight gas sands and shale has opened new venues for development of unconventional plays in Pakistan.
Middle Indus Basin hosts important gas fields of Pakistan. Most of the wells in this basin are completed in conventional lower Goru Sands. Lower Goru formation consists of inter-bedded sequences of sands and shale. Its unconventional sand and shale plays hold immense potential which has not yet been exploited due to lack of technology and promising economics. Moreover, Sembar shale is the well known source rock in this basin holding large shale gas potential. GIIP estimates for Lower Goru tight sands excluding the shale prospects are 8.4 TCF which are considered pessimistic due to lack of data in many fields.
From the currently suspended or abandoned wellbores of the Middle Indus Basin, a pilot project needs to be defined in each of the fields, to prove the technical and economical feasibility of tight Gas Potential of the Basin. Commencement of production from unconventional sands will enhance the production in a cost effective manner due to availability of infrastructure and facilities.
This paper focuses on the utilization of existing wellbores as well as data set and highlighting additional data acquisition requirements coupled with completion and multi-stage fracturing techniques for designing a pilot project. Case study of a pilot project in one of the fields of this basin is discussed. It encompasses the basic workflow, candidate selection criterion, Geo-mechanics, sector modeling, hydraulic fracture design and risk evaluation coupled with its use in full field development projects.
Effect of Operator Experience on the Outcome of Fiber Post Cementation With Different Resin Cements
Authors: Gomes GM , Gomes OMM , Reis A , Gomes JC , Loguercio AD , Calixto AL 
Published: December 2012

SUMMARY

Objectives
To evaluate the influence of operator experience (dentist vs student) and cementation system (Adper Scotchbond Multi-Purpose [SBMP] + RelyX ARC [1]; Adper Single Bond 2 [SB] + RelyX ARC [2] and RelyX U100 [3]) on the push-out bond strength (BS) of fiber post to radicular dentin.

Materials and Methods
The roots of 48 extracted human maxillary central incisors were prepared and divided into six groups (n=8), according to combination of the above factors. Glass fiber posts were cemented in accordance with the instructions of the manufacturer of each cementation system. After water storage at 37°C for one week, the roots were cross-sectioned into six 1-mm thick slices and the push-out test was performed (0.5 mm/min). Data were statistically analyzed by two-way analysis of variance and Tukey tests (α=0.05). The BS results obtained by dentist and student for each cementation system were compared using the Student t-test (α=0.05).

Results
Higher BS means were observed for the expert operators, irrespective of the cementation system used (p=0.006). RelyX U100 showed the highest bond strength, but it did not differ from SBMP + RelyX ARC. The Student t-test revealed that only RelyX U100 was not affected by the operator's experience.

Conclusion
Within the limitations of this in vitro study, it can be concluded that the self-adhesive cement RelyX U100 showed the highest bond strength to the root canal in the student's group, and its performance was not affected by the operator's experience.
Les « décrocheurs » scolaires : une manifestation de l'effondrement de la fonction paternelle ?
Authors: Delaroche Patrick 
Published: December 2012

Résumé L’auteur constate que le « décrochage scolaire » est devenu un phénomène de société lié à l’effondrement de la fonction paternelle. Le passage, en 1970, dans les textes de loi, de l’autorité paternelle à l’autorité parentale en est le reflet concret. Il distingue la phobie scolaire du décrochage : si la première requiert avant tout des soins psychiatriques, le second nécessite une autre approche. Celle-ci, selon lui, réclame d’abord la restauration de l’autorité dans le dialogue, et ensuite seulement des solutions adaptées à la jeunesse actuelle.
External Fixation for Displaced 2-part Proximal Humeral Fractures
Authors: Benetos Ioannis S. , Karampinas Panayiotis K. , Mavrogenis Andreas F. , Romoudis Pavlos , Pneumaticos Spiros G. , Vlamis John 
Published: December 2012

Studies have reported conflicting results regarding external fixation for displaced proximal humeral fractures. Compared with open reduction and internal fixation, external fixation for displaced proximal humeral fractures avoids dissection and soft tissue stripping and leads to higher union rates, a lower incidence of avascular necrosis, less scaring of the scapulohumeral interface, and faster rehabilitation. Some authors have reported good or excellent results and minimum complications compared with open reduction and internal fixation; however, others have reported that external fixation does not ensure acceptable reduction and fracture stability, especially in patients with osteoporosis.
This article describes 18 patients with displaced 2-part fractures of the surgical neck of the humerus treated with closed reduction and external fixation using the Tension Guide Fixator (Gexfix SA, Carouge, Switzerland) external fixation system between 2010 and 2011. The patients included 14 women and 4 men with a mean age of 39 years. Mean follow-up was 18 months (range, 15–24 months). Fracture union; function using the Constant score, University of California Los Angeles score, Oxford score, and Quick Disabilities of the Arm, Shoulder and Hand shoulder score; and complications were evaluated. All patients experienced fracture union at a mean of 11 weeks (range, 9–13 weeks). The Tension Guide Fixator was removed without anesthesia at the outpatient clinic at a mean of 6 weeks (range, 4–8 weeks) with no loss of reduction or secondary displacement after removal. At 1-year follow-up, mean Constant and University of California Los Angeles scores were excellent, mean Oxford score showed satisfactory joint function, and mean Quick Disabilities of the Arm, Shoulder and Hand score showed minimal pain with no disability.
Intramedullary Nailing and Angulation Prevention in Distal Metaphyseal Tibial Fractures
Authors: Isik Mustafa , Subasi Mehmet , Karsli Burcin , Saricicek Vahap , Karsli Gulseren 
Published: December 2012

Intramedullary nailing, which is preferred in tibial diaphyseal fractures, is also frequently used in distal third tibial fractures. Various angular deformities, including varus/valgus deformity, may be observed during postintramedullary nailing. Orthopedic surgeons use several methods to prevent this problem.
In this study, at least 2 static locking screws were placed proximal and distal to the nail during intramedullary nailing of distal third tibial fractures. No additional supportive methods were used. The efficacy of this technique in the prevention of postoperative angular deformities was retrospectively investigated. Thirty-four patients with distal third tibial fractures who were treated with intramedullary nailing were included in the study. Angulations were measured in the anteroposterior and lateral planes on plain radiographs obtained preoperatively, on postoperative day 1, and after fracture union. Angulations measured on postoperative day 1 were compared with those measured after fracture union, and an increase was observed. Based on statistical analyses, the increase in the angulations was not significant.
In distal third tibial fractures, when fixation was performed by placing 2 static screws distal and proximal to the intramedullary nail following adequate reduction, the angulations that developed during the period until union were not significant in terms of causing deformity, although additional fixation methods are not used.
Metallosis-induced Iliopsoas Bursal Cyst Causing Venous Obstruction and Lower-limb Swelling After Metal-on-metal THA
Authors: Algarni Abdulrahman D. , Huk Olga L. , Pelmus Manuela 
Published: December 2012

The formation of iliopsoas bursal cystic lesions after total hip arthroplasty is an infrequently reported condition. This article describes an unusual complication of a current-generation metal-on-metal total hip arthroplasty.
A woman presented with unilateral spontaneous lower-limb swelling that developed 5 years postoperatively. It occurred secondary to venous obstruction by a metallosis-induced iliopsoas bursal cyst associated with markedly elevated intralesional cobalt and chromium levels. Metal artifact reduction sequence magnetic resonance imaging showed that the bursal cyst was communicating with the hip joint and that it severely compressed the common femoral vein. Based on the findings of high local tissue metal ions and vertical cup positioning causing edge loading, the authors proposed an inflammatory reaction to metal debris that tracked into the iliopsoas bursa and formed a cyst. The patient underwent revision of the excessively vertical acetabular component and conversion to a ceramic-on-ceramic bearing interface, drainage of the bursal cyst, and synovectomy. No signs existed of local recurrence at 1-year follow-up.
To the authors’ knowledge, the occurrence of metallosis-induced iliopsoas bursitis with secondary pressure effects after contemporary metal-on-metal total hip arthroplasty has not been reported. When treating hip dysplasia, one must avoid maximizing cup–host bone contact at the risk of oververticalization. Iliopsoas bursal cystic lesions can lead to severe vascular compressive symptoms with no ominous radiographic findings. Physicians and orthopedic surgeons should be aware of the possibility of this complication in patients with unexplained unilateral lower-limb swelling.
Unilateral Meniscomeniscal Ligament
Authors: Chan Charles M. , Goldblatt John P. 
Published: December 2012

Four normal variants of meniscomeniscal ligaments have been previously reported in the anatomy, arthroscopy, and radiology literature. The anterior and posterior transverse meniscal ligaments are the 2 most commonly observed, with a reported frequency of 58% and 1% to 4%, respectively. The last 2 variants include the medial and lateral oblique meniscomeniscal ligaments and account for a combined frequency of 1% to 4%.
This article describes 2 patients with unilateral meniscomeniscal ligaments observed on magnetic resonance imaging. One patient had a unilateral lateral meniscomeniscal ligament extending from the anterior horn of the lateral meniscus to the posterior horn of the lateral meniscus and underwent conservative management. The second patient had a unilateral medial meniscomeniscal ligament with a concomitant medial meniscus tear and underwent arthroscopic intervention. The ligament was stable intraoperatively and, therefore, was not resected. Both patients had resolution of their symptoms.
These 2 variants are additions to the previously described 4 normal intermeniscal ligament variants. The functions of the 2 new variants described in this article are poorly understood but are thought to involve meniscal stability. Accurate descriptions of normal variants can lead to the proper management of anomalous rare structures and prevent false imaging interpretations because these structures can closely mimic a double posterior cruciate ligament sign. Furthermore, an understanding of the various normal variants of intermeniscal ligaments can prevent unnecessary surgery that could result in further iatrogenic meniscus injury.