bluuebunny/crossref_metadata_2025 huggingface dataset:
Technical Breakthrough in Production Engineering Ensures Economic Development of ASP Flooding in Daqing Oilfield
Authors: Jiecheng Cheng , Wanfu Zhou , Qingguo Wang , Gang Cao , Wenguang Bai , Changming Zhao , Meie Luo
Published: September 2014

Pilot tests commenced from 1980s in Daqing Oilfield have proved that ASP flooding could improve the recovery rate by 20% based on water flooding, while scaling issue in producers was the only factor which made it hard to reach that objective. Investigation in site indicated that more than 70 percent producers had scaling issues, and scaling types and degree in ASP producers varied dramatically in different wells and different period. In the peak of scaling period, the averaged running life was only a couple of months.

A project focused on the harness of scaling issue in ASP producers was implemented from 2002. In the first stage, the study aimed at getting the scaling principle in ASP producers. A series of monitoring and analysis on producing fluid's ion concentration were implemented in different ASP producers. The scale deposited on tubing in different depths were picked out and analyzed. The scaling mechanism of ASP producing liquids in artificial lift systems were created which presented the varying principle of scaling ions as well as the characteristics of scale in ASP producers. A set of scaling principle prediction plates was also created with a success ratio being above 90%.

In the second stage, a series of anti-scaling artificial lift techniques were developed including new anti-scaling pump, chemical scale removers and scale inhibitors, and other matching techniques. The new anti-scaling techniques were put into application from several wells up to near 1,000 wells. The operating rate has been improved by 4.13 percent as well as the operating cost decreased by 72.77%.

The technical breakthrough in anti-scaling artificial lift systems improved the operating life of ASP producers considerably. It applied solid foundation for ASP flooding to become a beneficial method for mature oilfield development in commercial scale.
Controlled Freeze Zone Technology for the Commercialization of Australian High CO2 Natural Gas
Authors: Valencia Jaime A. , Denton Robert D. , Northrop P. Scott , Mart Charles J. , Smith Ransdall K.
Published: September 2014

The simple separation of CO2 from natural gas by distillation would involve cryogenic temperatures at which CO2 solidifies. Most CO2 separation processes avoid this and use instead solvents that bind to CO2 molecules. For solvent regeneration, the binding process is reversed by addition of heat, lowering of pressure, or both. This adds extraneous chemicals and processes. The Controlled Freeze Zone™ brings back the simplicity and efficiency of a single step distillation process for the separation of CO2 from natural gas. Rather than avoiding the freezing of CO2, it allows it to take place, albeit in a very controlled fashion. The technology has shown the potential to more efficiently and cost-effectively separate carbon dioxide and other impurities from natural gas, and to discharge these contaminants as a high-pressure liquid stream ready for underground injection, either for enhanced oil recovery applications or for acid gas injection disposal.
An LWD Open-Hole Sigma for Time-Lapse Reservoir Monitoring - Case Study from South East Asia
Authors: Khairul Azhar A B , Hassan Nur Atiqah , Thanapala S M , Han Mei , Lee Samie , Roberts Iwan
Published: September 2014

Sigma log has long been crucial in cased-hole evaluation as it is one of a few measurements that can be made through complicated well completions. In fresh water environments, sigma log was used to discriminate gas from liquid; in some cases can differentiate water from oil, hence used subsequently for time-lapse reservoir monitoring to indicate changes in fluid type over production. A problem arises when no baseline sigma is available for time-lapse comparison. Traditionally a synthetic baseline sigma log may be artificially derived but suffers from uncertainty due to compounding of any errors in original volumetric interpretation as well as errors in the endpoint estimations.

The measurement of formation sigma under open hole condition has been enabled by a downhole pulsed neutron generator (PNG), installed in a multi-function logging while drilling (LWD) tool. The relatively large LWD collar reduces significantly the influence of borehole salinity which results in accurate sigma measurement while drilling. Thus a direct sigma baseline can be obtained in open-hole without errors brought from volumetric interpretation and sigma endpoint estimation. Verification of mud filtrate invasion can be done through Multi Depth of Investigation (MDOI) sigma measurements.

In order for an LWD baseline sigma measurement to be suitable for time-lapse analysis, the instrument response should be accurate, precise and repeatable by the subsequent cased-hole logging instrument. Sigma logs from both open-hole LWD and cased-hole wireline conveyed tools, over intervals of similar depth, were compared in offset wells within the same license block. Some 25 datasets from 5 producing fields in the region were examined and statistical analysis affirmed the response characteristics of both logs were emanating compatible. It confirms the data compatibility measured by both tools and supports the potential application of open-hole sigma log to serve as a baseline log for future time-lapse application.
Estimating Probability of Failure for Drilling Tools with Life Prediction
Authors: Carter-Journet K. , Kale A. , Zhang D. , Pradeep E. , Falgout T. , Heuermann-Kuehn L.
Published: September 2014

Drilling tools are subject to numerous operational parameters such as revolutions per minute (RPM), vibration (lateral, stickslip and axial), pressure, torque and temperature. These parameters can greatly fatigue even the most robust tool depending on where and how the tool is operated. Lifetime prediction methodologies represent an affordable and statistically significant way to estimate the probability of failure (risk) of drilling tools in a cost effective way. Understanding the potential risk is vital to ensuring reliability, performing the most efficient maintenance on the equipment and improving drilling performance. Sophisticated risk-modeling techniques reduce uncertainty in drilling operations by making use of readily available operational field data, thus eliminating the need for costly laboratory experiments. Blind spots in the decision making process are eliminated by proactively identifying precursors to costly failures in the field. Preemptive guidance during maintenance periods, for parts that may have otherwise been overlooked based strictly on procedure, is enabled. Statistical models that relate the operating environment to component life are derived from field component failure data, and introduce a fresh way to boost the drilling tool efficiency. A Bayesian-based model selection technique is also developed which incorporates operating environment variables after each successful drilling run to dynamically select the model that gives the best survival probability, ensuring maximum utilization of a component, while avoiding failure and improving the overall reliability of the tool in the field. The implementation of lifetime prediction methodologies also leads to lowered life-cycle and maintenance costs, reduced risk and improved operational performance. The paper presents the methodology used to estimate the probability of failure of drilling tools and further illustrates how to reach risk-informed decisions.
Lessons Learnt from the Large Scale Application of Image Logs to Unconventional Resources
Authors: Meyer Jeremy J. , Mildren Scott D. , Bartdorff Oliver , Tavener Emma
Published: September 2014

Image logs are a key tool in understanding unconventional reservoirs, providing geomechanical information and characterisation of natural fractures. This information can prove crucial in completion design and optimising production, especially where hydraulic stimulation is considered.

Image log datasets associated with unconventional developments can be large, utilise a variety of different tool types and contain data across multiple vintages. The size of the datasets requires multiple interpreters to facilitate interpretation in a reasonable time frame, while the different tool types require an interpretation scheme that is effective for image logs of different types. These factors necessitate a rigorous quality assurance system to ensure the data quality, and consistency of interpretation across multiple interpreters and tool types to maximise the utility of the interpretation results.

This paper presents a workflow for assessing large image log datasets practically derived from assessment of large datasets from multiple unconventional and conventional assets as applied to large Australian unconventional assets. Key elements of this workflow include: ·A tool independent quality control checklist that can be applied prior to interpretation.·Classification of image quality with respect to image log type.·Classification system for coal bed methane cleat characterisation of coals.·Classification system for fracture characterisation independent of tool type.·Classification system for stress related deformation independent of tool type.·A post interpretation quality control checklist to ensure consistency between multiple interpreters.
Application of Closed Loop Control Logic to Optimise End-of-life Cycling Production in a Mature Gas Field
Authors: Winterfield C. D. , Missikos J. , Tio R. , Dalgety B.
Published: September 2014

The Moomba North gas field is situated in the Cooper Basin in central Australia. Production commenced in 1969 and as the field has matured, liquid loading of wells has become more prevalent. In order to maximise recovery from wells nearing end of life whilst minimising the cost of deliquification methods, a well cycling technique has been implemented. Alternating pressure build-up periods with subsequent flowing periods of flush production allows increased bottom hole flowing pressure to sweep liquids accumulated in the well bore.

Parameters dictating desired build up pressure and low-flow shut-in rate have traditionally been calculated and/or determined empirically, requiring regular monitoring and updating to maintain optimal flow rates in line with changing system conditions. Improvements to this methodology have been achieved through implementation of an ‘intelligent’ closed loop control logic code which iteratively monitors and adjusts set points based on historic well performance. This represents an application of technology which mimics engineering input without the need for human intervention. Trial operation on several wells has exhibited the ability of the code to respond to field conditions and operational issues – in some cases increased average flow rate has been observed when compared with parameters manually determined by field engineers.

This paper will outline the well control philosophy and development of the control logic. System implementation and additional logic built in to address irregular system conditions and equipment faults will also be included along with field data from trial results.

The implementation of closed loop control logic for well control has exhibited improved business outcomes via collaboration between production engineering, process and control engineers and information technology. The use of an automated closed loop system for mature field well control represents progress in intelligent field control in Australia and provides potential for adaptation to further applications in multi-well control.
World's First Deepwater Propellant Perforation for a Depleted Carbonate Subsea Gas Well in Malampaya
Authors: Rao K. V. , Brinsden M. S. , Gilliat J. , Tan K Y. , Bhagwat M. , Harvey N. , Bhushan V.
Published: September 2014

This paper describes the operational planning and process safety due diligence performed to ensure safe and successful operations in the world's first deepwater propellant perforation in a carbonate reservoir. The Malampaya gas field in the Philippines is a depleted carbonate reservoir with five subsea development wells. The Malampaya Phase 2 Project that concluded in Q2 2013 involved drilling two new infill wells MA-11 and MA-12. Given the uncertainty in prognosis (Carbonate K-Phi) and the greater risk of not securing wells with high deliverability as per the well objectives, it was decided to use some form of near wellbore stimulation to bypass the near well bore damage zone caused by cement losses and cuttings lost to the formation while drilling the 300 m reservoir section. Propellant perforation technology solution was selected based on optimization of rig time, ineffectiveness of acid jobs in a karstified, fractured carbonate and process safety considerations of acid handling on a dynamically positioned rig. 200 m reservoir section was perforated safely and successfully with 3–3/8″ propellant perforation gun with 30% propellant loading on a 2″ coiled tubing in each of these two subsea wells. A standard 6 SPF shot density and 60 degree phasing was adopted with deep penetrating charges to bypass the damage zone suspected from drilling and cementing losses in this depleted carbonate. Both the wells delivered finally in excess of 100 MMscf/day during the well test on the rig as expected. This paper outlines the expected vs. actual well performance; process safety due diligence with an elaborate modeling focus on the worst case scenario (i.e. no cement behind the 7″ liner). Static and dynamic coil modeling results are shared along with an overview of the transient modeling conducted to optimize the final perforation interval on both the wells based on the actual lithology information.
Wettability Alteration during Low-Salinity Waterflooding in Carbonate Reservoir Cores
Authors: Alameri Waleed , Teklu Tadesse Weldu , Graves Ramona M. , Kazemi Hossein , AlSumaiti Ali M.
Published: September 2014

Production enhancement by low-salinity waterflood in carbonate formations is a subject of intense speculation. Several mechanisms are attributed to enhanced oil recovery by low-salinity waterflooding in carbonate formations. Review of experimental data in the literature indicates that the main mechanism involves interaction of Na+, Cl−, Ca2+, Mg2+, SO42− and crude oil carboxylate ions (R-COO−) with the rock in the electrical double layer (EDL) near the surface of carbonate pores, leading to wettability alteration.

In this study, we performed four seawater floods in heterogeneous low-permeability carbonate cores followed by low-salinity floods. The core permeability is between 0.5 to 1.5 md, and porosity in the range of 18 to 25%. Cores were aged for eight weeks at reservoir pressure and temperature. We also conducted pendant drop oil-brine IFT measurement, and captive oil-droplet contact angle at different brine salinity, with and without the presence of surfactant.

The carbonate core flood results show that removing NaCl from seawater or diluting the seawater twice and four times yielded about 8% incremental oil. In one experiment, the change in the effluent ionic concentrations was measured, and it was observed a decrease in Ca2+, Mg2+, Cl−, and SO42−. Using pendant drop IFT measurements, oil-brine IFT increased with decreasing salinity both in presence and in absence of 1,000-ppm surfactant. From captive oil-droplet contact-angle measurements, it was observed that cleaned un-aged carbonate core slabs were water-wet, and became more water-wet as salinity decreased (both in presence and in absence of 1000-ppm surfactant). The wettability of crude-aged carbonate core slabs altered from oil-wet to intermediate-wet as salinity decreased. And, the wettability changed from intermediate-wet to water-wet with decreasing salinity in presence of 1,000-ppm surfactant. Moreover, addition of small amount of surfactant alters the wettability of crude-aged or cleaned un-aged carbonate core slabs towards water-wet. The degree of water-wetness achieved by surfactant solution depends on salinity level.
Synergy and Emergence in Energy Policy Design
Authors: Blaskovich Frank
Published: September 2014

Effective energy policies should address the needs of all interested stakeholders. We used computer modeling to describe the interactions between energy production and economics. Policy solutions were based on regret analysis. Model results were generated for many possible futures to deal with uncertainties in future oil prices, producible oil reserves and maximum well rates, which were identified as the primary drivers of future revenues for both the state and producer in our model. We investigated the impacts of various tax and royalty policies (levers) individually as well as collectively. The results clearly define the limits of possible policies as well as those that might impact all stakeholders fairly. It was also clear that the best energy policy could not be predicted from the best solutions for each tax and royalty policy individually.

Our modeling approach can used to meet the needs of both the state and producer working together to find solutions that benefit all. It can also measure the relative benefits of existing energy policies and find ways to improve them.

This technique encourages the inclusion of many factors that are not normally studied in traditional approaches where production, economics and policy levers are treated separately. Our goal is to explore ways to improve the policymaker's ability to meet the needs of all stakeholders.

Our work shows that (1) even simple models can create unexpected policy results; (2) model synergy can have a great impact on results, and (3) regret analysis techniques can be very effective for defining policies. Except for our previous work, this type of policy exploration has not been reported in the petroleum literature.
Dynamic Behavior of a Multi-Layered Coal Seams Gas Reservoir in the Bowen Basin
Authors: Gouth F. , Belushko I. , Herwin H.
Published: September 2014

Fairview field is located in the Bowen Basin in South East Queensland and covers an area of approximately 1600 km2. It has been in production since 1994, from the 6 main coal seams of the Bandanna Formation. Presently, about 150 wells are on-stream feeding the domestic gas market. Further development is in progress to supply the Gladstone LNG plants on Curtis Island in 2015.

This paper focuses on a developed zone in the North of the field where extensive production and pressure data; more than 15 years, are available. The majority of the wells in the area are commingled and target the sweet spots with permeability ranging from tens to a few hundreds mDs.

Material balance analysis observed a typical layered reservoir behavior which is consistent with permeability discrepancies measured between seams. It also provided a comprehensive large scale calibration of the gas accumulation split between well connected and poorly connected areas. This split tightly controlled the gas production performance and recovery.

A strong permeability increase over reservoir pressure depletion was also identified after the two-phase flow production period. The magnitude was a 10 fold increase over 300 psi of depletion which is likely related to the well known coal shrinkage effect. This observation is consistent with previously published data from the San Juan Basin in the US. Within the high quality seams, this phenomenon had limited impact on long-term production recovery; however the impact on expected-ultimate-recovery (EUR) was more significant in the poorer seams.

These two phenomena show that permeability characterization, including its relationship with reservoir pressure depletion, is a key element for better production forecast.
Nanofluids Application for Heavy Oil Recovery
Authors: Alomair Osamah A. , Matar Khaled M. , Alsaeed Yousef H.
Published: September 2014

The application of nanotechnology in the oil industry has become a useful approach in oil production. The main objective of this study is to investigate the effects of nanofluids on the recovery of heavy crude oil compared to water flooding. The nanofluids are prepared by the addition of pure and mixed nanoparticles; Silicon oxide, Aluminum oxide, Nickel oxide, and Titanium oxide at different concentrations to the saline water. The prepared nanofluids were screened to determine the suitable type for the heavy oil and rock samples subjected to the study. The effects of nanofluids on the interfacial tension and emulsion viscosity were also investigated. Nanofluids flooding tests were performed on heavy oil sample of 17.45 API using Berea Sandstone core samples with an average air permeability of 184 mD, a liquid permeability of 60 mD, and a porosity of 20%. After selecting the recommended type of nanofluid, additional tests were performed including the effects on asphaltene precipitation using a flow assurance system. The experimental results show that, the Aluminum oxide nanofluid at a concentration of 0.05 wt.% reduced the emulsion viscosity by 25%. The mixed nanofluid of Silicon and Aluminum oxide at 0.05 wt.% showed the highest incremental oil recovery among the other nanofluids. This nanofluid is expected to be the best type of chemical flooding due to its performance under reservoir condition (high pressure, temperature, and water salinity) and its capability to oppose asphaltene precipitation.
History Matching CSG Production in the Surat Basin
Authors: Howell S. , Furniss J , Quammie K , Norman K , Erriah L
Published: September 2014

In 2009, QGC (a BG Group business) first planned to produce coal seam gas (CSG) in the Surat Basin as feedstock for a new Liquefied Natural Gas (LNG) plant. Subsurface models and associated field development plans were generated to underpin the investment case for the Queensland Curtis LNG (QCLNG) Project. This paper discusses history matching experience from QGC's Surat Basin reservoir simulation models, the challenges involved, and how these challenges have been overcome.

Similar to conventional reservoirs, full-field numerical simulation is necessary to accurately account for well interference and broader reservoir connectivity. Simulationalso fully integrates modelled 3D static property variations and honours the physics of multi-phase flow through porous media. CSG reservoirs possess unique characteristics which differ from conventional reservoirs and tend to increase the challenge of history matching. Some of these challenges include the physics of diffusive flow from the matrix into fractures that combines with relative permeability to create a more complex multi-phase flow problem. Another challenge is the requirement to de-water the coal before gas production commences and the associated stress dependency of coal properties. At the same time, the nature of CSG developments makes conventional history-matching approaches impractical given the large number of wells and the need for quick turnaround and fast-cycle decision making, especially during development ramp-up. These demands are set against a lean business environment where cost efficiency is paramount.

The properties of Walloon Subgroup (WSG) coals in the Surat Basin are unique compared to other CSG basin plays worldwide. The WSG is characterised by low to moderate coal rank, highly interbedded seams distributed through an extremely low permeability inter-burden, and highly variable coal permeability throughout the basin. Some of these differentiating properties of the WSG make history matching these reservoirs very challenging.

This paper presents guidelines for overcoming these challenges and history-matching CSG production in a dynamic simulation model of the Surat basin WSG. Handling of uncertainty is discussed to consider a range of possible history-matches for 345 wells with 9 years of production history. The history matching guidelines that have been developed are enabling a faster turnaround of model predictions, capturing key uncertainty parameters and informing field development decision-making.
Appraising Shale Gas Reservoirs Using Stimulation Data
Authors: Lehman Lyle V.
Published: September 2014

This paper discusses a workflow for developing shale gas reservoirs. The workflow has evolved over three decades of experiences with trial-and-error stories along the way. Perhaps the most difficult learning experience reveals that traditional non-reservoir rocks, although hydrocarbon bearing, can become excellent resources for gas production. From a historical perspective, “shale gas” usually refers to gas from shaley reservoirs that are brittle, meaning stimulation tends to create a very complex fracture system—often resulting in un-propped yet stimulated fractures.

The paper explains which data sources offer the best information for the investment in capital and time spent along with a hierarchy of technologies that help to define the actual reservoir quality and potential for development. Stimulation data offer the best avenue for invasive investigation of reservoir quality. When coupled with a frac model that is constrained to near wellbore conditions, stimulation data can detect far-field permeability and stress changes and determine the fracture geometry on a broad sense in terms of understanding fracture complexity. This paper offers several examples of the use of data sources and how they can be coupled and ultimately calibrated with stimulation data.
Effects of Rainfall Harvesting and Mulching on Corn Yield and Water Use in the Corn Belt of Northeast China
Authors: Lu Xianju , Li Zizhong , Bu Qingguo , Cheng Dongjian , Duan Wenxiao , Sun Zenghui
Published: September 2014

The Corn Belt of Northeast China is the most important corn production area in China, accounting for 30% of the total corn production. However, seasonal drought conditions limit local corn production. Field experiments were conducted in 2011 and 2012 in Lishu county (Jilin Province, China) to study the effects of ridge and furrow rainfall harvesting and mulching on corn yields, evapotranspiration (ET), and water use efficiency (WUE) in black and aeolian sandy soils. The treatments included flat planting bed (FB), plastic‐mulched ridges with bare furrows (RFB), and plastic‐mulched ridges with straw‐mulched furrows (RFM). For both soil types, the RFB and RFM treatments improved soil water conditions in the root zone. However, adding straw mulch did not consistently improve soil water content. In the black soil, the RFB treatment did not affect crop yield but increased WUE by 13% relative to the FB treatment in 2011. Furthermore, yield and WUE decreased by 30 and 24%, respectively, in 2012. In the aeolian sandy soil, the RFB treatment increased yield and WUE by 26 and 25%, respectively, relative to the FB treatment in 2011. However, the RFB treatment had no effect on yield or WUE in 2012. For both soil types, the RFM treatment did not significantly affect yield or WUE relative to the RFB treatment during 2011 or 2012. Therefore, the RFB treatment should only be used in aeolian sandy soils to achieve higher corn yields and WUEs and not be recommended for black soils when the soil water is sufficient.
Diversity of Maize Kernels from a Breeding Program for Protein Quality: II. Correlatively Expressed Functional Amino Acids
Authors: Jaradat Abdullah A. , Goldstein Walter
Published: September 2014

Modern maize (Zea mays L.) breeding and selection for large starchy kernels may have contributed to reduced contents of essential amino acids, including lysine, methionine, and cysteine, which represents a serious nutritional problem. We evaluated 1348 maize accessions classified into 13 populations and derived from crossing exotic, high‐quality maize landraces with Corn Belt stiff‐ and non‐stiff‐stalk heterotic groups. We used multivariate statistical analyses methods and validated partial least squares regression and structural equation models to study the homeostasis of these amino acids in relation to other phytochemicals in the maize kernel. New insights into the relative importance of several phytochemicals were derived from structural equation modeling, indicating that biochemical and physical constituents had negative impacts on amino acid contents regardless of heterotic group or endosperm texture and that mineral nutrients had positive effects; whereas, color space descriptors had mixed effects depending on heterotic group and endosperm texture. It was possible to develop quality protein germplasm with large lysine (4.2 g kg−1 dry mass) content and opaque endosperm that resembles translucent endosperm, while the conversion from opaque to translucent endosperm was associated with minimal loss of lysine. Accessions derived from DKXL370‐S11, DXKL370‐N11a‐N20, and ‘Nokomis Gold’ populations were identified as sources with high and stable contents of protein and all three amino acids, having either opaque or translucent endosperm textures.
Effects of Cultivation Strategies on Hybrid Pennisetum Yield in Saline Soil
Authors: Wang Dian , Guo Jian‐Rong , Liu Xiao‐Juan , Song Jie , Chen Min , Wang Bao‐Shan
Published: September 2014

Hybrid pennisetum (Pennisetum americanum × P. purpureum) is a popular energy grass with great potential for biofuel production. The objective of this research was to understand the effects of various cultivation strategies on the yield of hybrid pennisetum when growing in saline soil. The effects of plastic mulching, planting density, organic amendment, and additional fertilizer application on the yield and other characteristics of hybrid pennisetum were investigated in a 2‐yr field study conducted on the saline land of the Yellow River Delta, China. The results showed that mulching markedly increased the growth by reducing soil salinity and increasing soil moisture and soil temperature. Yield increased with plant density, and the highest yield (151.4 tons ha−1) was obtained with 27,778 plants ha−1. Plant growth also increased as organic amendment level increased from 0 to 1500 kg ha−1 and with addition of urea (applied when plant height was 80 cm and 150 cm). The abundance of culturable soil microorganisms was increased by the above cultivation measures. It can be concluded that suitable cultivation measures such as mulching, plant density, and application of organic and inorganic fertilizers, which were examined independently, greatly increased the biomass of hybrid pennisetum growing in a saline soil on the Yellow River Delta. The highest yield of hybrid pennisetum obtained was 175.3 tons ha−1.
Mapping Particle‐Size Fractions as a Composition Using Additive Log‐Ratio Transformation and Ancillary Data
Authors: Huang J. , Subasinghe R. , Triantafilis J.
Published: September 2014

During morphological description, one of the first properties assessed is soil texture. This is because it does not change significantly with time and it has the greatest impact on management (e.g., determining nutrient holding capacity). There is therefore an increasing need for high‐resolution digital prediction of soil texture. Unfortunately, determining the three particle size fractions (PSFs) using laboratory methods is time consuming. To add value to limited soil data, ancillary data coupled with spatial and nonspatial statistical methods can be used. However, the most commonly used technique, multiple linear regression (MLR) of individual PSFs, does not consider the special requirements of a regionalized composition. We coupled ancillary data via MLR modeling to an additive log‐ratio (ALR) transformation of the PSF to meet these requirements. The ancillary data included digitized air photo (e.g., Red digital numbers [DN]) and electromagnetic (EM38 and EM31) data. We found that for predicting clay at various depths, the EM38 and EM31 data were most useful. This was similarly the case for sand, with Red DN and the trend surface of some value. We also compared how prediction might be improved by using EM data measured on transects (which simulate measurements made on 1‐m transects) with interpolation from transects spaced 24 m apart. The results indicate that the use of EM data on a 1‐m transect using ALR‐MLR can improve precision by around 24% for clay, 3% for silt, and 17% for sand with regard to topsoil prediction. We also conclude that the ALR‐MLR technique has the advantage of adhering to the special requirements of a composition, with predicted values non‐negative and PSFs summing to unity (i.e., = 100%).
Comparing the Shot Length Distributions of Motion Pictures using Dominance Statistics
Authors: Redfern Nick
Published: September 2014

Comparing the shot length distributions of motion pictures we are interested in answering three main questions: do two (or more) films have similar shot length distributions? If there is a difference between shot length distributions, how large is that difference? Where do the shot length distributions of two films overlap and where are they most different? This article demonstrates the use of dominance statistics—Cliff's d, the Hodges-Lehmann median difference, and the empirical cumulative distribution function—for comparing the shot length distributions of motion pictures that make better use of the available shot length data and provide an unambiguous description of the difference in style between films that corresponds more closely to questions we wish to ask of film style than using average shot lengths compared to the most commonly used method of testing μ X = μ Y, where μ is some measure of central tendency. R functions for calculating these statistics are easily available and details of relevant packages are included.
Should the Annual Pelvic Examination Go the Way of Annual Cervical Cytology?
Authors: MacLaughlin Kathy L , Faubion Stephanie S , Long Margaret E , Pruthi Sandhya , Casey Petra M
Published: September 2014

The value of pelvic examination for healthy asymptomatic women has been called into question given the lack of benefit for ovarian and endometrial cancer screening, the ability to screen for sexually transmitted infections without a pelvic examination, and the uncoupling of the procurement of contraception with a pelvic examination. Still, there are indications for performing pelvic examinations in symptomatic women and in some high risk women. How do we as clinicians apply current evidence and expert opinion to our medical practice? Our recommendation to consider a pelvic examination at 3-5-year intervals with cervical cancer screening to elicit gynecologic and sexual health concerns offers a compromise between continuation of unnecessary annual pelvic examinations and complete elimination of these examinations.
Pregnancy and Cardiovascular Risk for Women with Turner Syndrome
Authors: Bondy Carolyn
Published: September 2014

Most women with Turner syndrome (TS) are infertile due to primary ovarian failure. However, approximately 5% experience spontaneous pregnancy, and recently, more women with TS have used assisted reproductive technology with donated oocytes (ART-OD) to become pregnant. The first generation of Turner patients undergoing ART-OD demonstrated a high rate of fatal aortic dissection in late pregnancy or postpartum. More recent observations, particularly from Nordic countries, suggest a lesser risk of dissection, but confirm a high rate of pre-eclampsia in ART-OD pregnancies. This article reviews publications since 2000 concerning maternal outcomes for pregnancies in women with TS to determine if specific risk factors such as type of pregnancy, age, or presence of underlying congenital cardiovascular disease may identify women at special risk.
The catalytic effect of honey on formation of reducing sugars during sucrose hydrolysis
Authors: Radovanovic Mirjana , Racic Branimir , Tanaskovic Snezana , Markovic Goran , Tomic Dalibor , Pantovic Jelena
Published: September 2014

In commercial apiculture, beekepers usually remove honey from hives and replenish food reserves with sugar syrup. When honeybees use sugar syrup (sucrose solution), they break down sucrose into glucose and fructose. These processes exhaust and weaken bees. In order to prevent bee exhaustion resulting from this processing, bees should preferably be supplied with ready made food before winter, i.e., with syrup in which sucrose has already been inverted. Feeding with inverted syrups is the most popular way of honeybee feeding. Beekeepers usually prepare inverted syrups by adding a weak organic acid (citric, oxalic, acetic or lactic acid) to sucrose solution at elevated temperatures. Inverted syrup production under uncontrolled pH, temperature and time conditions can cause the formation of 5-hydroxymethyl-2-furaldehyde (HMF), a compound harmful to bees. High quality inverted syrup can be obtained through the hydrolytic decomposition of sucrose by the enzyme invertase. Due to its invertase content, honey can be used as a biocatalyst for sucrose inversion. Invertase activity depends on the type, method and time of honey storage. This study evaluates the catalytic effect of acacia honey on formation of reducing sugars during hydrolysis of 50 wt.% sucrose solution. The ratio of reducing sugars and sucrose at 40?C, after 5 days of hydrolysis at a concentration of honey and 10 wt.% was 0.30 g reducing sugars/g of sucrose. The highest content of reducing sugars was achieved at a temperature of 35?C, after 48 h of invertion. In all samples of hydrolysates obtained at different temperatures (35?65?C), HMF was detected at concentrations of less than 4.32 mg kg?1. A high degree of negative correlation (coefficient of linearity ?0.94) was established between parameters of volumetric and polarimetric measurements during the hydrolysis of sucrose.
Evaluation of formulation and effects of process parameters on drug release and mechanical properties of tramadol hydrocloride sustained release matrix tablets
Authors: Nikolic Nenad , Medarevic Djordje , Ibric Svetlana , Djuric Zorica
Published: September 2014

This study investigates using of high molecular weight polyethylene oxide
(PEO WSR Coagulant) for the preparation of sustained release matrix tablets
containing high dose, highly water soluble drug, tramadol HCl. Proportion of
PEO polymer, type of insoluble filler, proportion of tramadol HCl, amount of
drug in tablet, tablet diameter and compression pressure were recognized as
critical formulation and process parameters and their influence on drug
release and tablet mechanical properties was evaluated. Percentages of
tramadol HCl released after 30 and 240 minutes were selected for evaluation
of drug release, while tensile strength was used as indicator of tablet
mechanical properties. Only proportion of tramadol HCl exhibits
statistically significant effect on percentages of tramadol HCl released
after 30 and 240 minutes, with higher, wherein increasing of the tramadol
HCl proportion increased its release rate among the evaluated variables in
selected ranges. All of the investigated factors exhibit statistically
significant effect on tablets tensile strength, with the largest influence
of filler type. Tablets prepared with highly compressible filler
(microcrystalline celullose) exhibit higher tensile strength and therefore
better mechanical properties to those prepared with partially pregelatinised
starch (Strach 1500).
A discrete-time system with service control and repairs
Authors: Atencia Ivan
Published: September 2014

This paper discusses a discrete-time queueing system with starting failures in which an arriving customer follows three different strategies. Two of them correspond to the LCFS (Last Come First Served) discipline, in which displacements or expulsions of customers occur. The third strategy acts as a signal, that is, it becomes a negative customer. Also examined is the possibility of failures at each service commencement epoch. We carry out a thorough study of the model, deriving analytical results for the stationary distribution. We obtain the generating functions of the number of customers in the queue and in the system. The generating functions of the busy period as well as the sojourn times of a customer at the server, in the queue and in the system, are also provided. We present the main performance measures of the model. The versatility of this model allows us to mention several special cases of interest. Finally, we prove the convergence to the continuous-time counterpart and give some numerical results that show the behavior of some performance measures with respect to the most significant parameters of the system
Analysis of an MMAP/PH1, PH2/N/∞ queueing system operating in a random environment
Authors: Kim Chesoong , Dudin Alexander , Dudin Sergey , Dudina Olga
Published: September 2014

A multi-server queueing system with two types of customers and an infinite buffer operating in a random environment as a model of a contact center is investigated. The arrival flow of customers is described by a marked Markovian arrival process. Type 1 customers have a non-preemptive priority over type 2 customers and can leave the buffer due to a lack of service. The service times of different type customers have a phase-type distribution with different parameters. To facilitate the investigation of the system we use a generalized phase-type service time distribution. The criterion of ergodicity for a multi-dimensional Markov chain describing the behavior of the system and the algorithm for computation of its steady-state distribution are outlined. Some key performance measures are calculated. The Laplace-Stieltjes transforms of the sojourn and waiting time distributions of priority and non-priority customers are derived. A numerical example illustrating the importance of taking into account the correlation in the arrival process is presented
Imitation learning of car driving skills with decision trees and random forests
Authors: Cichosz Paweł , Pawełczak Łukasz
Published: September 2014

Machine learning is an appealing and useful approach to creating vehicle control algorithms, both for simulated and real vehicles. One common learning scenario that is often possible to apply is learning by imitation, in which the behavior of an exemplary driver provides training instances for a supervised learning algorithm. This article follows this approach in the domain of simulated car racing, using the TORCS simulator. In contrast to most prior work on imitation learning, a symbolic decision tree knowledge representation is adopted, which combines potentially high accuracy with human readability, an advantage that can be important in many applications. Decision trees are demonstrated to be capable of representing high quality control models, reaching the performance level of sophisticated pre-designed algorithms. This is achieved by enhancing the basic imitation learning scenario to include active retraining, automatically triggered on control failures. It is also demonstrated how better stability and generalization can be achieved by sacrificing human-readability and using decision tree model ensembles. The methodology for learning control models contributed by this article can be hopefully applied to solve real-world control tasks, as well as to develop video game bots
Multiple neural network integration using a binary decision tree to improve the ECG signal recognition accuracy
Authors: Tran Hoai Linh , Pham Van Nam , Vuong Hoang Nam
Published: September 2014

The paper presents a new system for ECG (ElectroCardioGraphy) signal recognition using different neural classifiers and a binary decision tree to provide one more processing stage to give the final recognition result. As the base classifiers, the three classical neural models, i.e., the MLP (Multi Layer Perceptron), modified TSK (Takagi-Sugeno-Kang) and the SVM (Support Vector Machine), will be applied. The coefficients in ECG signal decomposition using Hermite basis functions and the peak-to-peak periods of the ECG signals will be used as features for the classifiers. Numerical experiments will be performed for the recognition of different types of arrhythmia in the ECG signals taken from the MIT-BIH (Massachusetts Institute of Technology and Boston’s Beth Israel Hospital) Arrhythmia Database. The results will be compared with individual base classifiers’ performances and with other integration methods to show the high quality of the proposed solution
Evaluating the Reliability of a Novel Neck-Strength Assessment Protocol for Healthy Adults Using Self-Generated Resistance with a Hand-Held Dynamometer
Authors: Versteegh Theo , Beaudet Danielle , Greenbaum Marla , Hellyer Leah , Tritton Amanda , Walton Dave
Published: September 2014

Purpose: To evaluate the intra- and inter-session test–retest agreement of a novel neck-strength assessment protocol using a hand-held dynamometer. Background: A literature review found a lack of neck-strength assessment protocols that are both portable and reliable. Hand-held dynamometry is a portable and inexpensive method of assessing muscle strength, but it is not commonly used for neck-strength assessment. Methods: A hand-held dynamometer was used to evaluate neck strength in 30 healthy participants. The device measured maximum force in cervical flexion, extension, side flexion, side flexion with rotation, and pure rotation, using the ipsilateral hand to apply isometric resistance over 3 seconds. Three measurements were taken over 6–8 days. Results: Test–retest intra-class correlation coefficients (ICCs) showed high reliability, ranging from 0.94 to 0.97 for all tested directions from Trial 1 to Trial 2 (intra-session reliability, ICC [2,1], absolute). ICC values demonstrated good to high inter-session reliability, ranging from 0.87 to 0.95 for all tested directions from Trial 1 to Trial 3 (ICC [2,1], absolute). Conclusion: The results suggest that the five test positions of the neck and upper-quadrant strength assessment protocol can be performed using hand-held dynamometry with good to high reliability.
'Jewish' Ethnic Options in Germany between Attribution and Choice
Authors: Bishop Kendzia Victoria
Published: September 2014

This article explores the issue of ethnic attributions versus options pertaining to Jewishness in Germany. The methodology is a combination of standard ethnographic fieldwork with Berlin-based high-school students before, during and after visits to the Jewish Museum Berlin (JMB) and auto-ethnography detailing and analysing my own experiences in and outside of the research sites. My goal is to illustrate particularities of interactions in sites like the JMB by contrasting the way in which Jewishness is handled in and outside of the standardised research situation. Further, the material points to continuities between anti-Semitism and Islamophobia. My analysis aims to open up further, productive discussion on this point.
Book Reviews
Authors: Koziura Karolina , Roper Jonathan
Published: September 2014

Mariusz Filip (2012), Od Kaszubów do Niemców: Tożsamość Słowińców z perspektywy antropologii historii [From Kashubians to Germans: Slovicians’ Identity from the Anthropological-Historical Perspective] (Poznań: Wydawnictwo Nauka i Innowacje), 238pp., Pb: PLN40/€10, ISBN: 978-83-63795-09-2.

Venla Sykäri (2011), Words as Events: Cretan Mantinádes in Performance and Composition: Studia Fennica Folkloristica 18 (Helsinki: Finnish Literature Society), 234 pp., Pb: EUR29.00, ISBN: 978-952-222-261-9.