bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phase Behaviour of CH4-C3H8-Heavy Oil Systems under Reservoir Conditions
Authors: Yang Ping , Li Huazhou , Yang Daoyong 
Published: June 2013

Abstract
In this paper, techniques have been developed to experimentally and theoretically study phase behaviour of CH4-C3H8-heavy oil systems under reservoir conditions. Experimentally, PVT tests are performed to measure saturation pressures and swelling factors of a C3H8-heavy oil system and a CH4-C3H8-heavy oil system under reservoir conditions, respectively. Theoretically, the volume-translated Peng-Robinson equation of state (PR-EOS) together with the modified alpha function has been used to model phase behaviour of the above solvent(s)-heavy oil systems. The binary interaction parameter (BIP) correlation is developed for CH4-heavy oil systems based on the literature data. As for the CH4-C3H8-heavy oil system with a fixed composition, both saturation pressure and swelling factor increase with temperature. The PR-EOS together with the modified alpha function and the newly developed BIP correlation is able to predict the saturation pressures and swelling factors of the CH4-C3H8-heavy oil systems with average absolute deviation of 11.89% and 2.22%, respectively.
Laboratory Study on Steam and Flue Gas Co-injection for Heavy Oil Recovery
Authors: Monte-Mor L. S. , Laboissière P. , Trevisan O. V. 
Published: June 2013

Abstract
The surface steam injection is the most common enhanced oil recovery (EOR) process used in heavy oil production. Nevertheless, there are limitations due to the heat loss for deep reservoirs and for offshore fields. Downhole steam generators (DHSG) are a new technology that opens a new path for recovery of heavy oil from deep reservoirs, offshore fields and extreme cold regions. Downhole steam generators eliminate the need for surface steam distribution systems, for flowlines and wellbore steam strings. The outflow of DHSG generators are a mixture of steam and flue gas. The main objective of this paper is to investigate the recovery dynamics of steam injection combined with flue gas at lab scale to recover a 16.14°API heavy oil from a sandpack. Superheated steam at 170°C was co-injected at flow rates between 5 and 4.5 ml/min (cold-water equivalent) with flue gas at flow rates between 150 and 340 ml/min in a linear cell built for the continuous injection of steam. From the results it can be asserted that co-injection reduces by 10% the amount of steam needed for an equivalent recovery. That translates in cutting steam generator costs on a per barrel of oil produced basis. The results of the tests addressed in this study provide: 1) The gas helps to keep the pressure behind the front more stable; 2) the co-injection of steam with flue gas accelerates the start of oil production when compared with steam injection alone; 3) Results indicates recovery factors up to 79%. The results favors DHSG as a promising technology for enhanced oil recovery of heavy oils, mainly for offshore fields or reservoirs at great depth.
Optimal Application Conditions of Solvent Injection into Oilsands to Minimize the Effect of Asphaltene Deposition: An Experimental Investigation
Authors: Moreno L.. , Babadagli T.. 
Published: June 2013

Abstract
Solvent injection into heavy-oil reservoirs is quite complex on account of the asphaltene destabilization that occurs due to the changes in temperature, pressure, and solvent type dissolved in oil. As a result of this destabilization, the asphaltene precipitates, flocculates, and eventually plugs the pores in the reservoir due to the formation of asphaltene clusters. In solvent applications, light molecular weight hydrocarbon solvents are preferred because of their high diffusion coefficient; but, as the carbon number of n-alkane solvents decreases, asphaltene precipitation increases. Therefore, the selection of the solvent and application condition is highly critical in cold and thermally-aided solvent applications.
In this research, low carbon number n-alkane (propane, n-hexane and n-decane) injection into sand pack systems saturated with heavy-oil (87651 cp) was evaluated at different pressure conditions that are applicable to typical Canadian oilsands reservoirs (100-300 psi) and temperatures (25-120 °C). First, the asphaltene behavior of different solvents at different pressures and temperatures were studied through deasphalting work in a pressure-volume-temperature (PVT) cell. Based on the quantitative (amount of asphaltene precipitated) and qualitative (microscopic images of asphaltene clusters) observations, the characteristics of asphaltene were classified in terms of their shape, size, and amount for different oil/solvent types, pressure, and temperature.
Continually, the same n-alkane solvents and heavy-oil were used in gravity drainage recovery experiments on unconsolidated sands. 2-D visual (Hele-Shaw type) and 3-D (cylindrical) sand pack experiments were carried out at the same temperatures and pressure conditions used for the PVT experiments. The asphaltene precipitated in the sand pack and in the produced oil was collected, and the standard SARA analysis was applied to determine the optimal operating conditions yielding the highest recoveries with minimal pore plugging. Moreover, the pore plugging process was analyzed through the visual inspection of 3-D sand pack experiments and the 2-D visual model using microscopic visualization and cross-checked against oil recovery rate. The asphaltene characteristics and concentration were evaluated using the microscope visualization and refractive index values, respectively. Eventually, optimal application conditions for solvent and thermally-aided solvent injection were listed for a wide range of heavy-oil and solvent types.
More Realistic Four-Phase Stability and Phase Splitting Calculations for Canadian Heavy Oil and Bitumen Reservoirs Using Solvent Injection Processes
Authors: Feizabadi Seyed Ali , Abedi Jalal , Chen Zhangxin 
Published: June 2013

Abstract
Steam assisted gravity drainage (SAGD) is the only economical and applicable method which the majority of companies are using to extract bitumen from the Alberta oil sands. However, there are some deficiencies in this method, including a high rate of heat loss to overburden and underburden formations in narrow (less than 15 m) oil bearing strata, a high operational cost for producing and injecting steam, and the treatment of the contaminated produced water. These disadvantages have researchers searching for other methods, such as solvent injection.
Different solvents can be considered for injection into a bitumen reservoir, such as ethane and carbon dioxide (CO2). Using CO2 as the solvent has two major advantages: achievement of miscibility with the bitumen, making it mobile by reducing its viscosity, and storage of CO2 underground. The latter is the goal of many researchers addressing the challenges of climate change.
In large-scale compositional simulations, equilibrium constants for different components in a solvent/bitumen mixture are a prerequisite. When there is no initial guess or empirical correlation for K values, the only way to obtain a true equilibrium constant is through phase stability and phase splitting calculations. Since experiments have acknowledged the formation of a second liquid phase in certain ranges of pressures and temperatures when mixing Alberta bitumen samples with solvents, fast and robust four-phase stability and splitting calculations are necessary. The four phases are the liquid diluted bitumen phase, the liquid solvent-rich phase, the solvent gas phase and the water (aqueous) phase.
The Peng-Robinson equation of state and its derivatives have been used for compressibility calculations in this study. Also, a combination of successive substitution and the Newton method has been used for phase splitting calculations for robustness.
The results have been compared to those of the available PVT simulation software (WinProp, Computer Modelling Group) and also to the experimental and modeling results of Mehrotra and Svrcek (1984). These results and comparisons indicate that the second liquid (solvent-rich) and water phases remain almost unchanged with changing pressures and temperatures; however, the components of the first liquid (diluted bitumen) and gas phases do change. This supports the idea of considering water as a phase and not as a component, which is the assumption in most compositional simulations.
Analysis of fast boundary-integral approximations for
modeling electrostatic contributions of molecular
binding
Authors: Kreienkamp Amelia B. , Liu Lucy Y. , Minkara Mona S. , Knepley Matthew G. , Bardhan Jaydeep P. , Radhakrishnan Mala L. 
Published: June 2013

Abstract
We analyze and suggest improvements to a recently developed
approximate continuum-electrostatic model for proteins.
The model, called BIBEE/I (boundary-integral based
electrostatics estimation with interpolation), was able to estimate
electrostatic solvation free energies to within a mean unsigned
error of 4% on a test set of more than 600 proteins¶a
significant improvement over previous BIBEE models. In this
work, we tested the BIBEE/I model for its capability to predict
residue-by-residue interactions in protein–protein binding,
using the widely studied model system of trypsin and bovine
pancreatic trypsin inhibitor (BPTI). Finding that the BIBEE/I
model performs surprisingly less well in this task than simpler
BIBEE models, we seek to explain this behavior in terms
of the models’ differing spectral approximations of the exact
boundary-integral operator. Calculations of analytically solvable
systems (spheres and tri-axial ellipsoids) suggest two
possibilities for improvement. The first is a modified BIBEE/I
approach that captures the asymptotic eigenvalue limit correctly,
and the second involves the dipole and quadrupole
modes for ellipsoidal approximations of protein geometries.
Our analysis suggests that fast, rigorous approximate models
derived from reduced-basis approximation of boundaryintegral
equations might reach unprecedented accuracy, if the
dipole and quadrupole modes can be captured quickly for
general shapes.
A Biomechanical Perspective on Physical Therapy Management of Knee Osteoarthritis
Authors: Farrokhi Shawn , Voycheck Carrie A. , Tashman Scott , Fitzgerald G. Kelley 
Published: June 2013

Synopsis Altered knee joint biomechanics and excessive joint loading have long been considered as important contributors to the development and progression of knee osteoarthritis. Therefore, a better understanding of how various treatment options influence the loading environment of the knee joint could have practical implications for devising more effective physical therapy management strategies. The aim of this clinical commentary was to review the pertinent biomechanical evidence supporting the use of treatment options intended to provide protection against excessive joint loading while offering symptomatic relief and functional improvements for better long-term management of patients with knee osteoarthritis. The biomechanical and clinical evidence regarding the effectiveness of knee joint offloading strategies, including contralateral cane use, laterally wedged shoe insoles, variable-stiffness shoes, valgus knee bracing, and gait-modification strategies, within the context of effective disease management is discussed. In addition, the potential role of therapeutic exercise and neuromuscular training to improve the mechanical environment of the knee joint is considered. Management strategies for treatment of joint instability and patellofemoral compartment disease are also mentioned. Based on the evidence presented as part of this clinical commentary, it is argued that special considerations for the role of knee joint biomechanics and excessive joint loading are necessary in designing effective short- and long-term management strategies for treatment of patients with knee osteoarthritis. Level of Evidence Therapy, level 5. J Orthop Sports Phys Ther 2013;43(9):600–619. Epub 11 June 2013. doi:10.2519/jospt.2013.4121
Effectiveness of Dry Needling for Upper-Quarter Myofascial Pain: A Systematic Review and Meta-analysis
Authors: Kietrys David M. , Palombaro Kerstin M. , Azzaretto Erica , Hubler Richard , Schaller Bret , Schlussel J. Mathew , Tucker Mary 
Published: June 2013

Study Design Systematic review and meta-analysis. Background Myofascial pain syndrome (MPS) is associated with hyperalgesic zones in muscle called myofascial trigger points. When palpated, active myofascial trigger points cause local or referred symptoms, including pain. Dry needling involves inserting an acupuncture-like needle into a myofascial trigger point, with the goal of reducing pain and restoring range of motion. Objective To explore the evidence regarding the effectiveness of dry needling to reduce pain in patients with MPS of the upper quarter. Methods An electronic literature search was performed using the key word dry needling. Articles identified with the search were screened for the following inclusion criteria: human subjects, randomized controlled trial (RCT), dry needling intervention group, and MPS involving the upper quarter. The RCTs that met these criteria were assessed and scored for internal validity using the MacDermid Quality Checklist. Four separate meta-analyses were performed: (1) dry needling compared to sham or control immediately after treatment, (2) dry needling compared to sham or control at 4 weeks, (3) dry needling compared to other treatments immediately after treatment, and (4) dry needling compared to other treatments at 4 weeks. Results The initial search yielded 246 articles. Twelve RCTs were ultimately selected. The methodological quality scores ranged from 23 to 40 points, with a mean of 34 points (scale range, 0–48; best possible score, 48). The findings of 3 studies that compared dry needling to sham or placebo treatment provided evidence that dry needling can immediately decrease pain in patients with upper-quarter MPS, with an overall effect favoring dry needling. The findings of 2 studies that compared dry needling to sham or placebo treatment provided evidence that dry needling can decrease pain after 4 weeks in patients with upper-quarter MPS, although a wide confidence interval for the overall effect limits the impact of the effect. Findings of studies that compared dry needling to other treatments were highly heterogeneous, most likely due to variance in the comparison treatments. There was evidence from 2 studies that lidocaine injection may be more effective in reducing pain than dry needling at 4 weeks. Conclusion Based on the best current available evidence (grade A), we recommend dry needling, compared to sham or placebo, for decreasing pain immediately after treatment and at 4 weeks in patients with upper-quarter MPS. Due to the small number of high-quality RCTs published to date, additional well-designed studies are needed to support this recommendation. Level of Evidence Therapy, level 1a-. J Orthop Sports Phys Ther 2013;43(9):620–634. Epub 11 June 2013. doi:10.2519/jospt.2013.4668
Dorsal Approach Rhinoplasty
Authors: Dubeta Kenneth R 
Published: June 2013

ABSTRACTDirect dorsal excision of skin and subcutaneous tissue is employed in rhinoplasty cases characterized by thick rigid skin to achieve satisfactory esthetic results, in which attempted repair by more conventional means would most likely frustrate both surgeon and patient.This historical review reminds us of the lesson: ‘History repeats itself.’ Built on a foundation of reconstructive rhinoplasty, modern cosmetic and corrective rhinoplasty have seen the parallel development of both open and closed techniques as ‘new’ methods are introduced and reintroduced again. It is from the perspective of constant evolution in the art of rhinoplasty surgery that the author presents, in Part II, his unique ‘eagle wing’ chevron incision technique of dorsal approach rhinoplasty, to overcome the problems posed by the rigid skin nose.How to cite this articleDubeta KR. Dorsal Approach Rhinoplasty. Int J Otorhinolaryngol Clin 2013;5(1):1-23.
Diagnosis and treatment of superficial vein thrombosis
Authors: Bauersachs R. M. 
Published: June 2013

SummarySuperficial vein thrombosis (SVT) is a common disease, characterized by an inflammatory- thrombotic process in a superficial vein. Typical clinical findings are pain and a warm, tender, reddish cord along the vein. Until recently, no reliable epidemiological data were available. The incidence is estimated to be higher than that of deep-vein thrombosis (DVT) (1/1000). SVT shares many risk factors with DVT, but affects twice as many women than men and frequently occurs in varicose veins. Clinically, SVT extension is commonly underestimated, and patients may have asymptomatic DVT. Therefore, ultrasound assessment and exclusion of DVT is essential. Risk factors for concomitant DVT are recent hospitalization, immobilization, autoimmune disorders, age > 75 years, prior VTE, cancer and SVT in non-varicose veins. Even though most patients with isolated SVT (without concomitant DVT or PE) are commonly treated with anticoagulation for a median of 15 days, about 8% experience symptomatic thromboembolic complications within three months. Risk factors for occurrence of complications are male gender, history of VTE, cancer, SVT in a non-varicose vein or SVT involving the sapheno-femoral junction (SFJ). As evidence supporting treatment of isolated SVT was sparse and of poor quality, the large, randomized, double-blind, placebocontrolled CALISTO trial was initiated assessing the effect of fondaparinux on symptomatic outcomes in isolated SVT. This study showed that, compared with placebo, 2.5 mg fondaparinux given for 45 days reduced the risk of symptomatic thromboembolic complications by 85% without increasing bleeding. Based on CALISTO and other observational studies, evidence-based recommendations can be made for the majority of SVT patients. Further studies can now be performed in higher risk patients to address unresolved issues.
Preparation of a Spontaneously Resolved Chiral Fluorescent System Containing 4‐(2‐Arylethynyl)benzoic Acid
Authors: Taniguchi Naoya , Shimomaki Ryutaro , Amako Tomoyuki , Sato Tomohiro , Tokutome Hayato , Tajima Nobuo , Kuroda Reiko , Fujiki Michiya , Imai Yoshitane 
Published: June 2013

AbstractA spontaneously resolved chiral fluorescent system was prepared from achiral 4‐(2‐arylethynyl)benzoic acid and racemic (rac)‐1‐phenylethylamine. Although functional chiral organic materials are usually prepared from chiral molecules, the chiral organic fluorophore described herein is successfully generated from achiral and racemic molecules to form a system that emits circularly polarized luminescence (CPL) in the solid state.
Maternal admixture and population structure in Mexican–Mestizos based on mtDNA haplogroups
Authors: Martínez‐Cortés Gabriela , Salazar‐Flores Joel , Haro‐Guerrero Javier , Rubi‐Castellanos Rodrigo , Velarde‐Félix Jésus S. , Muñoz‐Valle José F. , López‐Casamichana Mavil , Carrillo‐Tapia Eduardo , Canseco‐Avila Luis M. , Bravi Claudio M. , López‐Armenta Mauro , Rangel‐Villalobos Héctor 
Published: June 2013

ABSTRACTThe maternal ancestry (mtDNA) has important applications in different research fields, such as evolution, epidemiology, identification, and human population history. This is particularly interesting in Mestizos, which constitute the main population in Mexico (∼93%) resulting from post‐Columbian admixture between Spaniards, Amerindians, and African slaves, principally. Consequently, we conducted minisequencing analysis (SNaPshot) of 11 mitochondrial single‐nucleotide polymorphisms in 742 Mestizos of 10 populations from different regions in Mexico. The predominant maternal ancestry was Native American (92.9%), including Haplogroups A, B, C, and D (47, 23.7, 15.9, and 6.2%, respectively). Conversely, European and African ancestries were less frequent (5.3 and 1.9%, respectively). The main characteristics of the maternal lineages observed in Mexican–Mestizos comprised the following: 1) contrasting geographic gradient of Haplogroups A and C; 2) increase of European lineages toward the Northwest; 3) low or absent, but homogeneous, African ancestry throughout the Mexican territory; 4) maternal lineages in Mestizos roughly represent the genetic makeup of the surrounding Amerindian groups, particularly toward the Southeast, but not in the North and West; 5) continuity over time of the geographic distribution of Amerindian lineages in Mayas; and 6) low but significant maternal population structure (FST = 2.8%; P = 0.0000). The average ancestry obtained from uniparental systems (mtDNA and Y‐chromosome) in Mexican–Mestizos was correlated with previous ancestry estimates based on autosomal systems (genome‐wide single‐nucleotide polymorphisms and short tandem repeats). Finally, the comparison of paternal and maternal lineages provided additional information concerning the gender bias admixture, mating patterns, and population structure in Mestizos throughout the Mexican territory. Am J Phys Anthropol 151:526–537, 2013. © 2013 Wiley Periodicals, Inc.
Bite force and occlusal stress production in hominin evolution
Authors: Eng Carolyn M. , Lieberman Daniel E. , Zink Katherine D. , Peters Michael A. 
Published: June 2013

ABSTRACTMaximum bite force affects craniofacial morphology and an organism's ability to break down foods with different material properties. Humans are generally believed to produce low bite forces and spend less time chewing compared with other apes because advances in mechanical and thermal food processing techniques alter food material properties in such a way as to reduce overall masticatory effort. However, when hominins began regularly consuming mechanically processed or cooked diets is not known. Here, we apply a model for estimating maximum bite forces and stresses at the second molar in modern human, nonhuman primate, and hominin skulls that incorporates skeletal data along with species‐specific estimates of jaw muscle architecture. The model, which reliably estimates bite forces, shows a significant relationship between second molar bite force and second molar area across species but does not confirm our hypothesis of isometry. Specimens in the genus Homo fall below the regression line describing the relationship between bite force and molar area for nonhuman anthropoids and australopiths. These results suggest that Homo species generate maximum bite forces below those predicted based on scaling among australopiths and nonhuman primates. Because this decline occurred before evidence for cooking, we hypothesize that selection for lower bite force production was likely made possible by an increased reliance on nonthermal food processing. However, given substantial variability among in vivo bite force magnitudes measured in humans, environmental effects, especially variations in food mechanical properties, may also be a factor. The results also suggest that australopiths had ape‐like bite force capabilities. Am J Phys Anthropol 151:544–557, 2013. © 2013 Wiley Periodicals, Inc.
Synthesis of porous Al2O3‐PVDF composite separators and their application in lithium‐ion batteries
Authors: Wang Huifeng , Li Haibin , Yu Lijun , Jiang Yanmei , Wang Kaixue 
Published: June 2013

ABSTRACTIn this article, a modified tape casting method is employed by dispersing and ball milling of Al2O3 powders in the poly (vinylidene fluoride) polymer, with the aim of developing uniform nanocomposite separators in the lithium‐ion cell system. The surface morphology, pore structure, heat‐resisting property, infrared property, and cell performance of the nanocomposite separators are investigated. The experimental results indicate that ball milling plays an important role in yielding homogeneous, porous nanocomposite separator membranes. The developed separator membranes exhibit high thermal stability and excellent electrochemical performance, therefore, are promising for use in the lithium‐ion cell systems. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2886–2890, 2013