bluuebunny/crossref_metadata_2025 huggingface dataset:
Elastic-Plastic Behavior and Limit Load Analysis of Casings
Authors: Morita Nobuo
Published: August 2014

Most companies producing from high compaction reservoirs continue using casings even if they find that these casings have been elongated or compressed exceeding the yield stress (Furui, et al., 2011). The magnitude of elongation and compression of these casings are often 3 to 5% while the strains at the yield strength are supposed to be 0.3–0.5%. Since casings are actually used beyond casing yield strength, field engineers should take into account the casing properties during plastic deformation. In this study, extension, compression and radial loading tests were conducted from H-40 to V-150 casings up to failure. The tests gave the following results:

Under extension tests, the casings were uniformly deformed beyond the yield strength. The uniform deformation continued while the casings were stretched by 4 to 25% until non-uniform deformation was induced. The constitutive relations were constructed simulating the elastic and plastic deformations up to the failure. The radial compression tests showed stability of casings was maintained until the stresses at four cross-points of the stress concentration areas exceeded the yield strength. The higher grade casings did not significantly increase the maximum strength after yielding while lower grade casings significantly increased the strength while being stretched or compressed uniformly after yielding.

The analyses show that the casings were uniformly deformed until the maximum strength so that they were usable. The peak load of the uniform deformation is the limit load since they rupture after the uniform deformation. When casings are compressed or extended by geo-technical loadings, thicker casings with a lower grade prevent rupture and kinks while higher grade casings tend to rupture with a large formation deformation. When casings are compressed by directional geo-technical load, the casings start losing the load-support capability after the stresses at four cross-points of the casings exceed the yield stress. Selecting a proper grade and thickness of casings are the key for mitigating casing failure where the data of casing deformation beyond the yield strength are essential information for casing designing using geomechanical models.
Improving Drilling Economics Through Drilling Fluids and Solids Control in the Eagle Ford - Case Examples and Results
Authors: Guo Quanxin , Wang Youyou , Deplaude Oriane , Fout Gary
Published: August 2014

Drilling of shale oil and gas presents a unique opportunity for improvement. Since many similar wells are drilled during the life of a basin, even a small improvement can produce invaluable economic benefits. Drilling data of Eagle Ford wells were collected and analyzed to identify and rank major factors affecting drilling performance and economics. Solutions were developed and applied to Eagle Ford wells, resulting in savings in both drilling fluids cost and drilling days.

Drilling data of 965 horizontal Eagle Ford shale wells drilled between 2010 and 2013 by nearly 40 operators were collected and analyzed. Well drilling history was recreated from drilling data and reports. By analyzing this large number of wells with regard to well design, drilling procedures, drilling fluids, and solids-control methods, we confirmed the significant progress made in reducing drilling days and cost while increasing the lateral length over the years. The analysis also confirmed the detrimental effects of low gravity solids (LGS) on drilling operations. By comparing drilling fluids with high and low LGS concentration, it was found that high LGS concentration (> 9 or 10%, depending on the operator and data set) were associated with about 20% higher drilling fluids cost and an additional 2 to 3 drilling days per well. LGS are known for resulting in slower drilling, more non-productive-time (NPT) events, and downhole tool failures. By focusing the analysis on the most troublesome wells, it was found that the top NPT events were tools failure, wellbore instability, lost circulation, and stuck pipe.

This paper also presents an advanced solids-control solution and the early results of applying it in the Eagle Ford basin. This improved solids-control system is based on batch processing and staged centrifugation, used in tandem with chemically enhanced flocculation. It removes the ultrafine particles that cannot be removed with a conventional dual-centrifuge system. A comparison has been made between wells drilled by the same operator and drilling rig. Although the sample size in this comparison analysis may be too small to yield meaningful statistic results, the limited data showed a drilling-fluids cost saving (including solids-control costs) of 4.2 USD/ft by decreasing dilution and chemical additions, and an average drilling-time savings of 4.4 days per well.
Designing and Running a Special Oil-Based Mud for a North Sea HPHT Campaign
Authors: Kabanov Maxim , Telford Elizabeth , Gray Chris
Published: August 2014

A major operator in the North Sea had a requirement for a special fluid system to drill a series of HPHT exploration and appraisal wells. The operations had to overcome substantial technical challenges, with an expected bottom hole temperature near 400°F, anticipated reservoir pressures around 17,000 psi and narrow margins between formation pore pressure and fracture pressure. The oil-based mud had to fulfill a number of requirements, including thermal stability, consistent properties and predictable density behaviour, especially given the extensive wireline programme. The first part of this paper discusses the approach taken to the initial laboratory design work, with special consideration given to selection of weighting agent and HPHT testing regimes. With a suitable, environmentally acceptable fluid formulated, the second part of the paper deals with operational considerations given to wellsite maintenance and testing that allowed the three-well campaign to be completed successfully. Careful monitoring ensured that fluid properties remained stable throughout the drilling phase, and enabled a sustained, balanced rheological profile. This was necessary to minimize effective circulating density in the narrow drilling window, and to prevent sag during drilling and lengthy logging periods. The successful use of this special fluid contributed to the success of the wells. The fluid achieved excellent hole conditions, removing the need for costly wiper trips and delivering excellent wireline logs. Furthermore, the fluid's stability facilitated the resolution of well-control situations that often required slow, controlled circulation.
Optimization of the Emergency Glass Plugs Opening with Technology of Riserless Light Well Intervention
Authors: Tepka Piotr
Published: August 2014

Glass plugs technology was initially installed on Skarv field in Norwegian Continental Shelf. In partnership with technology provider, the new concept of completion barrier plugs was dynamically implemented. Its purpose was to close the lower formations of reservoir until the time the well was ready to proceed with production from those zones. The early years showed that even if this technology is forward-looking, the risk of failure and intervention still exists.

According to the operator's data three out of ten wells demanded the emergency glass plug opening and in the rest of cases the small complications occurred. Emergency breaking of the glass plug involves renting a unit and running the wireline with a tractor. It is an additional cost that can be optimized by understanding the challenge and proposing the accurate approach. Base of this research is the analysis of failure cases, activities that have been taken up by an operator and final outcomes from the operations. It is supplemented by the analysis of the optimal intervention concept according to economic calculations and market availability. The aim of the research is to transfer the knowledge acquired from failure cases into the recommendation for running such interventions and provide criteria for the final assessment of available solutions.
Self-Powered Intelligent Data Retrieval Gauge for Unconventional Well Testing Using DFIT Technology
Authors: Karaman Turker , Waldman Nathan , Tompkins Darryl , Swartley Adam , Redman Michael
Published: August 2014

Pressure transient testing has been the standard method used to obtain well information such as reservoir pressure, permeability, and skin in conventional reservoirs. However, with the shift towards unconventional, ultra-low permeability reservoirs, the only type of test that is economically practical for operators to use to determine reservoir and fracture properties is a diagnostic fracture injection test (DFIT). The DFIT provides a simple, cost-effective method for identifying fracture design parameters and essential reservoir properties in a relatively short period of time. Both fracturing and reservoir properties are critical inputs for proper fracture design, optimization, and reservoir characterization.

When performing a DFIT, it is critical to use a high-quality pressure gauge that is thermally compensated, capable of one-second sampling and with a resolution of 0.01 psi. Detection of subtle pressure changes over a short period of time is essential in analyzing the fall-off data to determine reservoir characteristics accurately.

The recently developed Self-Powered Intelligent Data Retriever system (SPIDR®) is an option for capturing accurate pressure data from the surface for use in DFIT analysis. This system provides a lower cost alternative that allows operators to view and download the data periodically during the fall-off without data interruption and without erasing the data. The downloads can then be reviewed to provide near real-time analysis, and also, will help determine when the test has been completed.

A case study will be discussed that will show how data from a high-quality surface gauge mirrors that of bottomhole pressure gauges and can provide accurate DFIT analytical results more economically.
Bayesian Inversion of Rate of Penetration (ROP) Data and Sonic Logging Data for Estimation of Unconfined Compressive Strength and Pore Pressure
Authors: Wu Zhan , Suryanarayana P. V. , Vasantharajan Sriram , Whitney Bill
Published: August 2014

In this paper, we propose an innovative use of MWD and Sonic logging data for better estimation of UCS. Sonic logging data and real-time ROP measurements are integrated into a Bayesian inference framework, employing empirical sonic correlations and an ROP model. Combining the two types of data sets under a single inference scheme can help reduce the uncertainty in UCS estimation and in prediction of ROP.

The prior mean of the parameters employed in the sonic correlations is interpreted from sonic logging in offset or analog well(s). The UCS estimation for the target well is inferred by application of the least square minimization approach to yield approximations for the maximum a posteriori (MAP) estimation. Verification of the inference procedure is demonstrated on actual MWD data and Sonic datasets. The results show that the UCS generated from the empirical correlation of sonic travel time slowness still contains large uncertainty. Joint inversions of ROP data and sonic velocity measurement reduce the uncertainty in the UCS estimation. The results indicate that the calibration of ROP data is critical before use of empirical correlations to estimate UCS. This paper also addresses the possibility of deriving the pore pressure and UCS simultaneously with quality MWD and sonic data.
Incident Free Rig Transition Planning and Project Management
Authors: Andersen Henrik
Published: August 2014

During 2013 Chevron Thailand has gone through a large scale rig transition, bringing five new build rigs (three jackups and two tender assisted rigs) into our operation and releasing four aging rigs. Significant challenges were to maintain world class safety performance through the transition while also maintaining drilling efficiency. During 2014 one more new build rig has been delivered.

This paper describes how the rig transition was managed to ensure the delivery of drill-ready rigs and incident free startup of drilling operations. Main focus is placed on the tools, processes and procedures developed and applied for the first 90 days of operation. Key elements being:

– Combined contractor and operator lead pre-startup safety engagements – Crew transition, management of short service employees and on the job crew training – Methodology and tools applied for repeated assessment of crew safety culture, well control competency, fluency in safety management system, stop work authority, operator's tenets of operation and continual improvement process – How these results were applied to track progress and determine rig readiness for operations, offline activity and simultaneous operations

The paper also presents the new build project management and integrated rig acceptance testing as well as the main elements of the rig demobilization plan.

The intent of this paper is to share best practices and lessons applicable for operators and contractors starting operations on a new build drilling rig.
Mud Cap Drilling (MCD) with Continuous Annular Injection - Offshore Malaysia
Authors: Hamizan Azyyati A. , Hasbullah Utvanuddin P. , Upadhyay Abhishek , Buch M. , Eren S. , Zahari M. Zulkhairi , Roslan M. Rizwan , Hajiyeva M. , Rashid E. Rashidi , Ishak S. Nadiah , Johari M. Raimi , Satar Afzan A. , Razali Ezuan H. , Huong C. S. , Payne J. , Voshall A. , Mathews T. , Houng N. H.
Published: August 2014

Losses are common in carbonate reservoir drilling due to highly fractured nature of limestone and the existence of karst. Complete and unsustainable fluid losses encountered in the offset well threatened the loss of the primary barrier – hydrostatic column – that could result in a catastrophic well control incident / loss gain scenario. Total losses in the offset well were approximately 25,000 bbls. Losses were stopped only with cement plugs. A total of 17 days were spent to mitigate the losses. The well was plugged and abandoned.

To drill and develop this marginal carbonate field with efficient and low cost wells, the team decided to use Mud Cap Drilling (MCD) with Continuous Annular Injection. The sub-normal nature of the reservoir allowed the use of this technique as opposed to a more conventional Pressurized Mud Cap Drilling (PMCD) method utilizing Light Annular Mud (LAM). Continuously injecting seawater down the annulus to prevent gas migration while simultaneously injecting seawater down the string to transport cuttings up to the loss zone and cool the bit, eliminated the mud cost and fluid logistics that normally dominate the PMCD process.

During the development program, two horizontal wells penetrated the carbonate at the same TVD and only one of the wells experienced complete and unsustainable losses. Carbonate structures are anisotropic. Several wells can be drilled that do not experience losses yet the next well in the same field could require MCD. For this reason it is necessary to prepare for MCD as a contingency when drilling carbonates. No kicks or well control issues were experienced during this development program. Well barrier policies were accomplished by maintaining the annulus with overbalanced fluid (seawater) at all times using this method. Well was drilled to TD and completed successfully, and all the primary well objectives were achieved. Drilling time was reduced significantly by over 50%, and fluid cost for this operation was reduced to almost zero. This innovative technique was applied for the first time in PCSB Malaysia drilling operations.
Innovative Cement Spacer Improves Well Cementing Integrity - 60 Case Histories Reviewed
Authors: Budiawan Aditya , Farahani Hamidreza S. , Anugrah Andri , Brandl Andreas
Published: August 2014

This paper reviews the challenges faced during well cementing in the fields of East-North Kalimantan, Indonesia and describes utilizing an innovative cement spacer to successfully solve these issues. Unconsolidated formations and depleted reservoirs are main causes for lost circulation during drilling and cementing operations often resulting in poor cement bond logs and failed Top of Cement (TOC) requirements. The common practice to address these well integrity problems is to apply lost circulation material and low density cementing systems designed at 10.5 to 11.0 ppg. This strategy did not always accomplish the desired results and remedial cement squeeze jobs were needed for many primary cement jobs.

To overcome these challenges, an innovative cement spacer system was engineered and successfully applied. The new environmentally friendly spacer system contains a biopolymer to mitigate loss circulation issues during cementing. It strengthens the wellbore wall by forming an effective seal along the formation, minimizing losses during cementing and preventing cement fall back after placement. The initial field application was immediately successful in obtaining full circulation returns during the cement job, a constant challenge on prior jobs. An added advantage was the cement slurry density could be increased from 10.5 up to 13.5 ppg without encountering any losses; despite exceeding the maximum theoretically allowable equivalent circulating density (ECD). As a consequence the increased slurry density improved early cement strength development which reduced wait-on-cement times and required using less concentration of expensive light weight cement materials. This, in turn, simplified operations and logistics and reduced costs.

Case histories are presented covering more than sixty successful cement jobs using the new spacer system. Specific cases are discussed where: 1. successful results were achieved despite partial to total drilling related losses during the drilling phase, 2. cement bond logs have improved and 3. Remedial jobs have been eliminated. Conservative cost savings utilizing the new spacer design is more than $2.5 million USD. The product can be applied on high-temperature, high-permeability formations, those with low fracture gradients and fragile, unconsolidated, and fractured formations.
Using Seismic While Drilling to Reduce Depth Uncertainty on an Exploration Well Offshore Thailand
Authors: Ahmed Aqil , Quoch Luc Nguyen , Vendrell Jaume
Published: August 2014

Knowing targets depths accurately for Carbonate Exploration wells is critical for a successful well construction process due to the kick / loss scenario if the carbonate is accidentally penetrated.

This paper demonstrates the use of innovative Logging-while-drilling seismic technology used offshore Thailand for the first time which furnishes seismic checkshot information whilst drilling to refine depth prediction ahead of the bit for accurate geostopping.

Field data will be shown to demonstrate this methodology.

Carbonate targets require casing to be set immediately above. Depth uncertainty from the surface seismic is usually in the range of over 50m up to 200m depending on the quality of the surface seismic acquired and the ensuing processing. Lack of offset well velocity information amplifies this uncertainty. By acquiring velocity information while drilling, the depth uncertainty is progressively reduced as drilling proceeds. This is achieved using the seismic while drilling technology, thus avoiding the need for a dedicated intermediate checkshot survey on wireline and saving rig time and cost. The technique consists of a downhole seismic receiver collar forming part of the bottom hole assembly and a surface acoustic source in the form of an airgun cluster. Seismic levels were acquired when drilling entered slips – a natural break in the drilling process and providing an acoustically quiet time. Each seismic level provided a real time seismic waveform which was processed for a Time-Depth pair to update the velocity model and hence refine the target depth prediction.

53 consecutive real time seismic levels were acquired refining the carbonate depth prediction shallower by 30m. The acquisition was transparent to rig operations. The initial error range for the depth was +/− 70m. Casing point was set successfully without penetrating the carbonate. Exploration wells lend themselves well to the use of this service for reducing depth uncertainty.
Perforating Gunshock Loads: Simulation and Optimization in 2014
Authors: Baumann Carlos , Brinsden Mark
Published: August 2014

The ability to predict and reduce large perforating gunshock loads and the associated risk of damage and nonproductive time is very important because of the high cost of most wells, especially deepwater high-pressure wells.

The aim of this paper is to present the most current (as of 2014) capabilities in simulation software to predict perforating gunshock loads produced by hollow carrier guns. This is a joint effort between operators and service companies to promote the discussion on dynamic gunshock modelling. The end goal of this paper is to communicate to a broader audience of oil and gas companies the most current knowledge on predicting perforating wellbore dynamics and the associated gunshock loads and to look ahead for future developments in dynamic gunshock modelling.

Both low- and high-pressure wells are susceptible to gunshock damage when they are perforated with inappropriate gun systems and/or under adverse conditions. As of 2014, there are several software tools available to predict gunshock loads. These software tools help engineers identify perforating jobs with significant risk of gunshock damaged, such as bent tubing and unset or otherwise damaged packers, gun damage, wireline weak-point pull-offs, etc. When the predicted risk of gunshock damage is large, engineers can make changes to the perforating equipment or job execution parameters to reduce gunshock loads and the associated risk of equipment damage and nonproductive time. With the available gunshock software, engineers can also evaluate the sensitivity of gunshock loads to changes in the perforating equipment, such as: gun type, charge type, shot density, tubing size and length, rathole length, and placement/setting of packers and shock absorbers.

In this paper, we describe the main sources of gunshock loads. We present examples showing typical loads on tubing and packers, and we elaborate on the load levels that can lead to equipment damage. Simulation examples included in this paper also illustrate how to reduce gunshock loads by modifying the equipment used. We illustrate how small changes that cost very little to implement can lead to a large reduction in both gunshock loads and the associated job failure risk.
Integrated Workflow of Geological Modelling, Hydraulic Fracturing and Reservoir Simulation for the Evaluation and Forecast of Unconventional Tight Oil Reservoirs
Authors: Cui Esther , Liu Jianchun , Wei Gang
Published: August 2014

Tight hydrocarbon reservoirs are a major unconventional reserve. To profitably develop such reserves, horizontal wells and multistage hydraulic fracturing techniques are applied to maximize the reservoir drainage areas and increase reservoir conductivity to the wellbores by creating flow channels in the tight reservoirs.

Without in-depth studies that include reservoir characterization, field modeling, well test and production data analysis by a multidisciplinary team, reservoir properties cannot be reproduced and well performance cannot be represented to accurately forecast production. Overestimating or underestimating production rates creates tremendous loss for oil companies or operators. Integrated workflow combines multiple disciplines and professionals for specific projects.

The target reservoir is in the central Jungger basin, northern China, which is a green field for tight oil reservoirs with an anticline structure, fault system and unconformity and stratigraphic traps. The paper presents the thorough reservoir characterization, systematic process and reference for a tight oil development plan. The high heterogeneity, low porosity, low permeability and production uncertainty in unconventional reservoirs sped up progress and investment in integrated workflow for reservoir development through risk quantification.

This paper presents a systematic study of unconventional resource characteristics, and describes an integrated workflow for reservoir characterization and development of tight oil reservoirs in northwest China which combines geology, seismic, geostatistics, well logging and core data. The process and methodology comprises a geological study, a field geological model with reservoir characterization, petrophysical modeling, numerical well testing, hydraulic fracture modeling based on a geomechanical study and a field reservoir simulation study. Reservoir grid is refined to capture the effect of hydraulic fracture on well performance, calibrate model using well testing and history matching for examining model accuracy, and then finally production of post-fracturing is estimated.

This paper also includes the details of sensitivity analysis proposed to address the critical uncertainties and strategy to enhance well deliverability such as well placement, half-fracture lengths, hydraulic fracturing stages and fracture conductivity.

The workflow enables the feasibility of coupling multiple disciplines including geology, geophysics, geostatistics, petrophysics and reservoir engineering into an integrated platform for information sharing, project management and strategy using static and dynamic data while simultaneously checking and updating reservoir data.
Development of Mature Fields Using Reservoir Opportunity Index: A Case Study from a Saudi Field
Authors: Varela-Pineda Alfonso , Hutheli Ahmed H. , Mutairi Saad M.
Published: August 2014

This paper presents a rigorous methodology to identify the remaining reservoir opportunities in order to enhance sweep efficiency and increase hydrocarbon production rate in a mature field under water flooding operations. Development of mature fields implies proper reservoir management practices to determine the amount and location of the remaining oil. It also entails optimal placement of new wells and re-entries to enhance the ultimate recovery.

As of today, common approaches to place new wells are usually based on oil column maps derived from saturation and production logs as well as the performance of the neighboring wells in the area of interest. The current work improves on the common practices by combining both static and dynamic variables extracted from the geological and simulation models to estimate the Reservoir Opportunity Index (ROI), which can effectively detect un-swept oil zones not seen by simple methods. The ROI along with other available information in the geological and simulation models such as, production history and well logs are then integrated in one platform to facilitate informed decisions for successful mature field development.

The initial formulation of ROI, previously presented by many authors in the industry, is improved to suit reservoir geology and conditions at different time steps, incorporating changes in oil saturation and reservoir pressure effects. The computed ROI is then normalized to allow accurate representation and comparison among various layers and areas.

The ultimate benefits of the proposed approach are realized when mapping the ROI for different reservoir layers and advising on the location of new wells and re-entries. Moreover, the applicability and the advantages of this work can be expanded to other areas such as: reservoir description, reservoir characterization, reserves estimation and depletion analysis.
Decolorization of Reactive Black‐5 byShewanellasp. in the Presence of Metal Ions and Salts
Authors: Imran Muhammad , Arshad Muhammad , Khalid Azeem , Hussain Sabir , Mumtaz Muhammad Waseem , Crowley David E.
Published: August 2014

In this study, effect of various metal ions and salts on biodecolorization of Reactive black‐5, azoreductase activity, and growth of Shewanella sp. strain IFN4 was evaluated. Among the tested metals, Cr+2, Pb2+, Ni2+, Fe2+, and Mn+2 did not inhibit the biodecolorization of reactive black‐5, azoreductase activity and bacterial growth. Three metals (Cu2+, Zn+2, and Co2+) delayed the decolorization process without completely inhibiting the reaction and also suppressed the bacterial growth. However, no dye decolorization was observed in the presence of Cd+2 (10 mg L−1). Furthermore, bacterium decolorized the dye at high concentration (15 mg L−1) of mixed metal ions. Strain IFN4 was also able to decolorize the dye at 50 g NaCl L−1 and 60 g Na2SO4 L−1. NaCl was found to be more inhibitory to bacterial growth than Na2SO4 and the reverse was observed for azoreductase activity. These findings suggest that strain IFN4 could be used in designing a bioreactor for the treatment of textile effluent.
Exercise Intervention to Reduce Depressive Symptoms in Adults with Intellectual Disabilities
Authors: Carraro Attilio , Gobbi Erica
Published: August 2014

People with intellectual disabilities are often reported as having depressive symptoms. Although the antidepressant effect of exercise has been systematically recognized, research concerning the role of exercise on depressive symptoms in people with intellectual disabilities is still scant. A 12-wk. exercise intervention for depressive symptoms in a group of adults with intellectual disabilities was conducted. Participants were 16 men and 11 women, randomly assigned to an exercise group ( n = 14) or to a control group ( n = 13). The Zung Self-Rating Depression Scale adapted for people with intellectual disabilities was administered at baseline, after 6 wk. and at the end of the intervention. There were statistically significant reductions in scores for the exercise group compared with the control group. Results support the notion that exercise can improve well-being in people with intellectual disabilities.
Psychometric Properties of a Chinese Version of the Duke University Religion Index in College Students and Community Residents in China
Authors: Wang Zhizhong , Rong Y. , Koenig Harold G.
Published: August 2014

A Chinese version of the Duke University Religion Index (DUREL) was developed and the psychometric properties were assessed. The study was conducted in two separate samples of 1,285 college students and 2,564 community residents. To assess test-retest reliability, the DUREL was re-administered after 1 wk. to 105 college students and 199 community residents. In both samples, three factors were extracted using principal components factor analysis with Promax rotation, which is consistent with the scale content. Internal consistency reliability was acceptable. Test-retest ICCs ranged from .45 to .89 in college students and .75 to .93 in community residents. The Chinese version of the DUREL is a useful measure of religiosity in Mandarin-speaking populations.
Preschool Motor Development Predicting High School Health-Related Physical Fitness: A Prospective Study
Authors: Vlahov Eric , Baghurst Timothy M. , Mwavita Mwarumba
Published: August 2014

To address the obesity epidemic there is an increasing effort to emphasize physical activity and fitness in adolescence as opposed to fundamental motor skills. However, what effect this might have on health-related fitness is unclear. This study sought to determine the degree to which motor development competencies in preschool could predict high school fitness. In the initial study, participants were 143 male and 139 female preschoolers ( M age = 4.8yr., SD = 0.7) from four preschool programs in suburban area of a Southern state who completed the Test of Gross Motor Development. Eleven years later, 75 boys and 65 girls ( M age = 15.8yr., SD = 0.7) from the original sample were located and completed the AAHPERD Health Related Fitness Test (1.5mile run, sit-up, sit-and-reach, body fat percentage). Test of Gross Motor Development scores were found to be strong predictors for all measures of fitness, but object control skills were more predictive of overall physical fitness than locomotor skills. Therefore, educators should consider teaching sport skill development in early childhood over general activity to improve long-term fitness.
Effects of Functional Electrical Stimulation on Gait Recovery Post-Neurological Injury during Inpatient Rehabilitation
Authors: Lairamore Chad I. , Garrison Mark K. , Bourgeon Laetitia , Mennemeier Mark
Published: August 2014

This stage 2 trial investigated the therapeutic effect of single channel, peroneal functional electrical stimulation (FES) for improving gait and muscle activity in people with neurological injuries who were enrolled in an inpatient rehabilitation program. Twenty-six patients (16 male; M age = 51.3 yr., SD = 16.2; 2–33 days post-injury) completed the study. Participants were randomly assigned to an experimental group ( n = 13) or control group ( n = 13). The experimental group received FES and the control group received sensory stimulation during 45-min. gait training sessions three times a week for the duration of their stay in a rehabilitation facility (average of four sessions for both groups). Changes in gait speed, tibialis anterior muscle electromyography (EMG), and FIM™ locomotion scores were compared between groups. No significant differences were found, as both groups demonstrated similar improvements. The current results with this small sample suggest a low dose of gait training with single channel FES did not augment gait nor EMG activity beyond gait training with sensory stimulation; therefore, clinicians will likely be better served using a larger dose of FES or multichannel FES in this clinical population.
An Exploratory Study of Self-Consciousness and Emotion-Regulation Strategies in Health Care Workers
Authors: Andela Marie , Auzoult Laurent , Truchot Didier
Published: August 2014

The goal of this study was to assess relations between public self-consciousness, private self-consciousness (self-reflectiveness and internal state awareness), and two emotion-regulation strategies: cognitive reappraisal and expressive suppression. 59 employees of a public hospital completed a survey. Public self-consciousness was not associated with either emotion-regulation strategy, while both dimensions of private self-consciousness were related to the strategies. While self-reflectiveness was correlated with expressive suppression, internal states awareness was associated with cognitive reappraisal.
Interpersonal Views of Narcissism and Authentic High Self-Esteem: It is Not all about you
Authors: Byrne J. Stephen , O'Brien Edward J.
Published: August 2014

Employing peer-rating methodology, this study examined relationship issues in narcissists versus individuals with authentic high self-esteem. Undergraduates ( N = 147) were assigned to rate someone (a “target”) they knew well who was most similar to a narcissistic prototype, an authentic self-esteem prototype, or a control person. Participants rating narcissistic targets reported significantly more interpersonal problems with the target and more avoidant and revenge behaviors directed toward them than did participants rating authentic self-esteem or control targets. Authentic high self-esteem was associated with positive social relationships. Large effect sizes suggested substantial interpersonal differences observed by peers interacting with narcissists compared to authentic high self-esteem individuals.
Masked Response Priming across Three Prime Proportions: A Comparison of Three Accounts
Authors: Bodner Glen E. , Lee Lawrence
Published: August 2014

Unconscious priming is sensitive to contextual factors. The present study examined this adaptive process using masked arrow primes (« or »). Some targets required specific ‘fixed’ left/right responses (« or ») and others required ‘free’ left/right responses (<>). Different groups ( n = 30 each) received response-congruent primes (SOA=75msec.) on 0.2, 0.5, or 0.8 of the fixed-response trials. Fixed responses were facilitated by congruent primes and free responses were faster when congruent with the prime. Critically, these masked priming effects emerged only in the 0.8 group. The pattern of extant prime-proportion effects in this paradigm best supports an adaptive associative-strength account rather than memory-recruitment or response-bias-suppression accounts.
Effect of Different Warm-up Procedures on the Performance of Resistance Training Exercises
Authors: Ribeiro Alex S. , Romanzini Marcelo , Schoenfeld Brad J. , Souza Mariana F. , Avelar Ademar , Cyrino Edilson S.
Published: August 2014

Warm-up has been shown to mediate numerous acute physiological alterations that have been purported to confer beneficial effects on performance. This study investigated the acute effects of different warm-up procedures on resistance training performance. Employing a randomized, counterbalanced crossover design, 15 men performed 3 exercises (4 sets of bench press, squat, and arm curl at 80% of 1RM) to failure in 4 conditions (control, specific, aerobic, and combined). Outcome measures included the sum of repetitions and a fatigue index measuring the decline between sets. There was no significant difference for the sum of repetitions or for fatigue index among conditions for the 3 exercises. Performance in the resistance training exercises was not influenced by warm-up.
Influence of Yoga on Body Image Satisfaction in Men
Authors: Flaherty Mary
Published: August 2014

The aim of this study was to examine the influence of yoga practice on body image satisfaction in men. Male Figure Drawings were used to explore body image satisfaction in yoga beginners ( n = 26, M age = 40.3yr., SD = 11.6), experienced yoga practitioners ( n = 22, M age = 46.4yr., SD = 11.6), and non-yoga practicing aerobic and weight training exercisers ( n = 34, M age = 41.2yr., SD = 11.9). Satisfaction was significantly higher among the yoga groups than the exercisers. There was no statistical difference between the body satisfaction scores of the experienced yoga group and the beginner yoga students. This may suggest that individuals drawn to yoga have greater body satisfaction than exercisers, and that regular yoga practice possibly further increases body satisfaction.
Blood Lactate Response, Oxygen Consumption, and Muscle Activity during Treadmill Running with Constraint
Authors: Haudum A. , Birklbauery J. , Sieghartsleitner R. , Gonaus C. , Müller E.
Published: August 2014

The induction of self-organization during running with a special harness may lead to reduced energy requirements. This experiment was designed to investigate the effect of practicing with a rubber tubing constraint attached between the heel and the hip for 7 wk. (18 treadmill running sessions) on oxygen consumption, caloric unit cost, blood lactate concentration, and muscle activity. 18 male recreational runners ( M age = 26.3yr.) were assigned to either an intervention or a control group. The intervention group trained with the constraint and the control group trained without it. Test 1 was conducted before the intervention, Test 2 after the intervention, and Test 3 7 wk. after Test 2 (no training between Tests 2 and 3). At Test 1, lactate and muscle activity were significantly increased during constrained running. For lactate, a significant decrease was found in the intervention group for running with the constraint; at Test 3, lactate returned to Test 1 level. No notable changes occurred in the physiological parameters. Furthermore, there was no observed transfer effect on normal running.
Social Context and the Spread of HIV: An Evolutionary Game-Theoretic Investigation on the Impacts of Social Stigma on Epidemic Outcomes
Authors: Ferguson William , Nguyen Trang
Published: August 2014

We provide a theoretical foundation for analyzing how social stigma and adopted behavioral traits affect the transmission of HIV across a population. We combine an evolutionary game-theoretic model—based on a relationship signaling stage game—with the SIR (susceptible-infected-recovered) model of disease transmission. Our evolutionary model specifies how two types of social stigma—that which accompanies an HIV+ condition and that which follows associating with an HIV+ partner—influence behavioral propensities to honestly report one’s condition (or not) and to unconditionally accept relationships (or not). With respect to reporting an HIV+ condition, we find that condition stigma impedes the fitness of honest reporting, whereas association stigma impedes the relative fitness of concealing an HIV+ condition; and both propensities can coexist in a polymorphic equilibrium. By linking our model to the SIR model, we find that condition stigma unambiguously enhances disease transmission by discouraging both honest reporting and a society’s acceptance of AIDS education, whereas association stigma has an ambiguous impact: on one hand it can impede HIV transmission by discouraging concealing behavior and unconditional relationship acceptance, but it also compromises a society’s acceptance of AIDS education. Our relatively simple evolutionary/SIR model offers a foundation for numerous theoretical extensions—such as applications to social network theory—as well as foundation for many testable empirical hypotheses.
Modeling and Analysis of Transport Processes and Efficiency of Combined SOFC and PEMFC Systems
Authors: Rabbani Abid , Rokni Masoud
Published: August 2014

A hybrid fuel cell system (~10 kWe) for an average family house including heating is proposed. The investigated system comprises a Solid Oxide Fuel Cell (SOFC) on top of a Polymer Electrolyte Fuel Cell (PEFC). Hydrogen produced from the off-gases of the SOFC can be fed directly to the PEFC. Simulations for the proposed system were conducted using different fuels. Here, results for natural gas (NG), dimethyl ether (DME) and ethanol as a fuel are presented and analysed. Behaviour of the proposed system is further investigated by comparing the effects of key factors such as utilisation factor, operating conditions, oxygen-to-carbon (O/C) ratios and fuel preheating effects on these fuels. The combined system improves the overall electrical conversion efficiency compared with standalone PEFC or SOFC systems. For the combined SOFC and PEFC system, the overall power production was increased by 8%–16% and the system efficiency with one of the fuels is found to be 12% higher than that of the standalone SOFC system.
Predictive Densities for Day-Ahead Electricity Prices Using Time-Adaptive Quantile Regression
Authors: Jónsson Tryggvi , Pinson Pierre , Madsen Henrik , Nielsen Henrik
Published: August 2014

A large part of the decision-making problems actors of the power system are facing on a daily basis requires scenarios for day-ahead electricity market prices. These scenarios are most likely to be generated based on marginal predictive densities for such prices, then enhanced with a temporal dependence structure. A semi-parametric methodology for generating such densities is presented: it includes: (i) a time-adaptive quantile regression model for the 5%–95% quantiles; and (ii) a description of the distribution tails with exponential distributions. The forecasting skill of the proposed model is compared to that of four benchmark approaches and the well-known the generalist autoregressive conditional heteroskedasticity (GARCH) model over a three-year evaluation period. While all benchmarks are outperformed in terms of forecasting skill overall, the superiority of the semi-parametric model over the GARCH model lies in the former’s ability to generate reliable quantile estimates.
Prevalence of Pneumoconiosis in Hubei, China from 2008 to 2013
Authors: Xia Ying , Liu Jiafa , Shi Tingming , Xiang Hao , Bi Yongyi
Published: August 2014

We have investigated newly reported pneumoconiosis cases in the province of Hubei, China from 2008 to 2013, to identify the major problems and challenges, and explore possible solutions for its prevention and control. We analyzed the data on new cases of pneumoconiosis from annual reports, including case distributions, patient ages, exposure duration, disease stages, and enterprise types. A total of 3665 new pneumoconiosis cases were reported between 2008 and 2013 in Hubei Province. Coal workers’ pneumoconiosis and silicosis, which accounted for 97.19% of the total, were the most common types. The duration of exposure of 33.32% cases was less than 10 years. Most of the new pneumoconiosis cases worked in industries that produced coal, nonferrous metal, or building materials. About 42.46% of pneumoconiosis cases were from small and medium-sized enterprises. The proportion of cases with combined pneumoconiosis and tuberculosis was 6.6%, and the incidence of tuberculosis was highest in workers with silicosis. The current situation of pneumoconiosis in China is serious. Lack of attention to occupational health, inefficient surveillance, and weak occupational health services may have contributed to the increased new pneumoconiosis cases.
Correction: Kramer, R.A., et al. A Randomized Longitudinal Factorial Design to Assess Malaria Vector Control and Disease Management Interventions in Rural Tanzania. Int. J. Environ. Res. Public Health 2014, 11, 5317–5332
Authors: Kramer Randall , Mboera Leonard , Senkoro Kesheni , Lesser Adriane , Shayo Elizabeth , Paul Christopher , Miranda Marie
Published: August 2014

The authors wish to make the following corrections to their paper published in the International Journal of Environmental Research and Public Health [1]:[...]
Clinical and Metabolic Parameters in Non-Small Cell Lung Carcinoma and Colorectal Cancer Patients with and without KRAS Mutations
Authors: Yilmaz Ahmet , Mohamed Nehad , Patterson Kara , Tang Yan , Shilo Konstantin , Villalona-Calero Miguel , Davis Michael , Zhou Xiao-Ping , Frankel Wendy , Otterson Gregory , Zhao Weiqiang
Published: August 2014

Lung cancer (LC) and colorectal cancer (CRC) are the first and second deadliest types of cancer worldwide. EGFR-based therapy has been used in the treatment of these cancers with variable success. Presence of mutations in the KRAS driver oncogene, possibly induced by environmental factors such as carcinogens in diet and cigarette smoke, may confer worse prognosis and resistance to treatment for reasons not fully understood. Data on possible associations between KRAS mutational status and clinical and metabolic parameters, which may help in clinical management, as well as in identifying risk factors for developing these cancers, are limited in the current literature. We sequenced the KRAS gene and investigated the associations of variations in 108 patients with non-small cell lung carcinoma (NSCLC), the most common form of LC, and in 116 patients with CRC. All of the mutations originated from the guanosine nucleotide and over half of all transversions in NSCLC and CRC were c.34 G>T and c.35 G>T, respectively. c.35 G>A was the most frequent type of transition in both cancers. Excluding smoking, the clinical and metabolic parameters in patients carrying mutant and wild type KRAS were similar except that the CRC patients with transversion mutations were 8.6 years younger than those carrying the transitions (P < 0.01). Dyslipidemia, hypertension, family cancer history, and age of diagnosis older than 60 years were more frequent in NSCLC than CRC (P ≤ 0.04). These results suggest that most of the clinical and metabolic parameters investigated in this study are probably not associated with the more aggressive phenotype and differences in response to EGFR-based treatment previously reported in patients with KRAS mutations. However, the increased rates of abnormal metabolic parameters in patients with NSCLC in comparison to CRC indicate that these parameters may be more important in the management of NSCLC. CRC patients carrying transition mutations are older than those carrying transversions, suggesting that age may determine the type of KRAS mutation in CRC patients.