bluuebunny/crossref_metadata_2025 huggingface dataset:
Drilling Technique Improves Directional Steering Control in Very Weak Formation and Reduces Wellbore Collision Risk
Authors: Ogwumike John , Ajijolaiya Yemi , Appleton Edmund , Schrader Hartmut Hans , Foekema Nico , Ruszka Jon , Wilson Harry , Adams Adeniyi
Published: March 2015

Directional drilling control in top-hole sections through very weak shallow sediments is challenging. The formation tends to wash out, reducing steering control. The lack of reliable steering results in well kick-off-points planned deeper than optimal, especially for extended-reach wells or under multi-well platforms where early well separation is advantageous. Additionally, when drilling in close proximity to existing wells, well collision risk increases.

As a result of these challenges, a major operator and international service company have developed, and proven, a hybrid drilling technique enabling reliable steering control in sediments which previously proved difficult to directionally drill through. The technique employs an automated rotary steerable system (RSS) and gyro-while-drilling tool operating in a directional jetting mode without rotation.

The wells are drilled from an offshore platform through dual conductors. In addition to the well collision risks normally associated with multi-slot platforms, dual conductors mean that the second well drilled from each conductor is initially in very close proximity to the first well.

Until this technique was developed, the top-hole sections were drilled with steerable motors because RSS were unable to steer consistently in the very weak shallow sediments. When the collision risk was passed, and the formations became firm enough for the RSS to operate, the steerable motor bottom hole assembly (BHA) was replaced with the RSS.

The hybrid RSS jetting technique provides several advantages; a single BHA run can drill to section TD, shallower kick-offs are possible and predictable steering control reduces the risk of collision. The lower energy of the non-rotating jetting system is also believed to reduce damage to an offset well in the event of collision.

The paper explains how the hybrid system was developed, and describes how it is applied and optimised in practice with real examples. Opportunities for further research are presented which may enable offset wells to remain on production, saving significant production loss and avoiding risk associated with well shut-in and start-up.
Design, Qualification, QAQC and Operational Performance of Completion Fluid, Reservoir Drill-in Fluid and Breaker - Tamar, Offshore Israel
Authors: Healy John , Sanford Jack , Hopper Tim , Dufrene Kerby , Fink Josh , Balderrama Christian , Steve Vickers , Mackenzie Grant
Published: March 2015

A case history from Offshore Israel is presented that describes the successful delivery of five (5) ultra-high rate gas wells (+250 MMscf/D) completed in a significant (10 TCF) gas field with 7 in. production tubing and an Open-Hole Gravel Pack (OHGP). Maximizing gas off-take rates from a gas reservoir with high flow capacity (kh) requires large internal diameter (ID) tubing coupled with efficient sand face completions. When sand control is required, the OHGP offers the most efficient as well as the most reliable, long-term track record of performance. A global study of ultra-high rate gas wells was made to select and finalize the design concept after which the commensurate engineering rigor was applied. This paper will highlight the design, qualification, Quality Assurance / Quality Control (QA/QC) and operational performance of the completion fluids inclusive of the Reservoir Drill-in Fluid (RDIF) and the breaker. Completion fluids are critical to the success and production efficiency of an OHGP. The completions were installed with minimal operational issues (Average NPT ≈4%). Production commenced on March 31, 2013. All wells have performed to expectations with maximum well rates up 340 MMscf/D.
Well Advisor - Integrating Real-time Data With Predictive Tools, Processes and Expertise to Enable More Informed Operational Decisions
Authors: Israel R. , Mason C. , Whiteley N. , Gibson K. , Dobson D. , Andresen P.A.
Published: March 2015

An increasing proportion of oil and gas production comes from the technically-challenging, deep-water/offshore environment, where drilling and completions teams continue to focus on enhancing safety and operational integrity and where the costs of non-productive time during well construction can be quite significant. BP identified opportunities to address these three issues through extending its use of real-time data and launched the BP Well Advisor (BPWA) Project to develop and deploy this technology to aid in further enhancing drilling performance.

This paper will share the lessons that the company has learned from this project and provide an introduction to the range of functionality within the technical solutions currently being developed and deployed. It will also discuss how the company and its project collaborators have worked together to deliver the well advisor as a solution package inclusive of the underlying technology, business transformation processes, solution deployment, training and support. This approach has been a key component of the project's success to date and has built a solid platform to support its planned future activities.

The objective of the well adviosr project is to facilitate the management and exploitation of real-time data. The system being developed integrates this real-time data with other predictive tools and processes to support delivery of the right information, in the right place at the right time. This helps the operational teams to make timely and well-informed decisions as they work to deliver safe and reliable wells. The project's key areas of operational focus are enhancing operational safety, improving well construction efficiency and life of well reliability.

The well advisor project has demonstrated success in helping the company to enhance all three areas of operational performance listed above, and efforts are ongoing to expand the system's technical capabilities and regional deployments globally. One highlight of the project to date has been its successful application to casing running where over 291 casing/liner strings in 4 major regions have now been run without a stuck pipe incident. This success alone is estimated to have saved over 250 days of non-productive time (NPT) based on historical data associated with stuck casing incidents prior to its introduction. Other functionality being deployed monitors cement placement, blow-out preventer (BOP) health, pressure tests and rigsite fluid management.

This paper will conclude with a summary of operational performance benefits derived to date from the implementation of the well advisor and give a preview of new functionality being considered for potential future deployments.
Designing and Testing a New Rotary Steerable System (RSS) for the Onshore Drilling Market
Authors: Gorrara Andrew , Grant Shona , Kvalvik Tore , Bakke Stig , Clark Peter
Published: March 2015

Whilst Rotary Steerable Systems (RSSs) have been used offshore and in high value directionally drilled wells for many years, their penetration into the land-based market has generally been slow. This is changing with the rise of unconventional shale drilling in North America. Here the small license/lease area combined with the need for as long a lateral as possible to boost productivity, is driving the market for improved rotary steerable tools than can build from a vertical to horizontal well profile in as short a radius of curvature as possible. The new tool discussed in this paper is a short RSS that is designed to deliver a 15 degrees per 100 foot build up rate (dogleg severity). It achieves this by the movement of two eccentric shafts relative to one another within the tool. These shafts are completely enclosed within a non-rotating stabilizer housing that maintains contact with the borehole wall and provides bit support. With this system the direction and inclination of the tool can be continuously adjusted as required, giving drillers a high level of control and maneuverability downhole.

The design philosophy is to make the tool as short and simple as possible to minimize potential failure mechanisms and hence deliver high reliability and lower drilling costs. The fully electric steering mechanism does not rely on externally moving pads or pistons. The tool also includes a unique sensor package that is located just behind the front stabilizer (and hence close to the bit), its own turbine generator, an innovative non-contact coupling for power and data transfer, and its own communications system that does not interfere with other Measurement-While-Drilling systems.

Three prototypes of the new RSS have been designed and tested so far. The first prototype (Prototype #A) successfully demonstrated 15 degrees per 100 foot dogleg severity capability. The second prototype (Prototype #B) was designed to evaluate the efficiency of the selected motor-gear design in moving the eccentric shafts when applying significant side loads. The third prototype (Prototype #C) was a complete rotary steerable tool that verified all aspects of the design, culminating in the drilling of directional holes in concrete blocks. This paper will describe the development of Prototype #C covering design, manufacture and the drill tests that verified the 15 degrees per 100 foot dogleg performance through concrete block drilling. The paper will also cover the subsequent design improvements made prior to manufacture of the field test prototypes (Prototype #D), and the planned environmental and endurance testing of Prototype #D prior to field testing. The field tests are planned for second quarter 2015.
Lubricants and Accelerated Test Methods for Expandable Tubular Application
Authors: Di Crescenzo Daniele , Shuster Mark , Petlyuk Alla , Ernens Dennis , Zijsling Djurre , Pasaribu Henry
Published: March 2015

Tubular expansion for well construction is a process accomplished by pulling (or pushing) a mandrel through a pipe downhole. This can be described as a tribological system that consists of the pipe and mandrel surface, a lubricant layer and a fluid. A successful expansion requires a lubricant that, not only ensures manageable expansion forces, but also provides a robust solution for downhole application. The desired lubricant should separate the mandrel from the pipe during a downhole plastic deformation and be thermally stable, chemically compatible with drilling fluids and withstand a long shelf life in harsh environments.

This paper describes a process for optimal lubricant selection using accelerated testing with a dedicated setup that mimics demanding down hole conditions during expansion processes.

Three commercially available lubricants, commonly used in tubular expansion or other similarly demanding applications, and a novel solid lubricant, developed specifically for tubular expansion applications, were tested. The test campaign focused on the influence of drilling fluids and temperature on the friction, wear and lubrication efficiency.

The novel solid lubricant showed superior performance compared to conventional lubricants demonstrating lower friction factor with expansion forces between 13% and 49% lower than with conventional expandable tubular lubricants, outstanding resilience in coping with alien particles in the drilling fluid, ability to mitigate the onset of stick-slip phenomena and good corrosion protection for the expandable tubular. It was therefore selected and successfully used in field-trial applications.
The Drilling Optimization Benefits of Direct Drillstring Surface Measurements–Case Studies from Field Operations
Authors: Wylie Robert , Soukup Ian , Mata Henry , Cuff Sean , Ho Anthony
Published: March 2015

Correct information is crucial to drilling effectiveness and well construction success, with the greatest data accuracy achieved by measurement instruments applied as close as possible to the target load. Until recently, most drilling parameters were derived from load measurements taken on supporting structures or equipment related to the drillstring—but not actually a part of the string. The remote position of these classic sensors from the desired load often resulted in unacceptable error rates.

SPE/IADC 163475 proposed a direct measurement system, designed by integrating drilling instrumentation into a standard top drive internal blow out preventer (IBOP). The instrumented IBOP (IIBOP) makes direct-load measurements of drilling parameters along the drillstring—just below the main shaft of the top drive—thereby circumventing the errors of the traditional measurements. This provides the timely, directly measured data needed to characterize drillstring phenomena required for drilling and equipment optimization purposes, without the mechanical losses of the traveling system. The system's primary purpose is to provide early warning signs of system failure or well control situations and to enable better decision making with regards to well construction.

The previous paper presented examples of the data captured during initial field trials. Since that time, the sensor system has been run on multiple wells, achieving more than a year of cumulative data collected and analyzed by drilling experts. This paper reviews the extension, uptake, and applications of the technology, and presents case studies to demonstrate the use of direct drillstring data, with emphasis on lessons learned from high-speed data analysis for drillstring dynamics.

Initial results demonstrate that the improved measurements provide more accurate values for surface mechanical specific energy (MSE), which is used to optimize applied drilling parameters such as weight on bit (WOB) and top drive rotation speed in revolutions per minute (RPM) for increased rate of penetration (ROP) and reduced risk of equipment failures. Additionally, improved measurements permit better friction factor estimations for greater knowledge of torque and drag effects on the drilling process, allowing drillers to initiate remedial actions earlier, and safely deliver longer extended-reach wells. The system's high-speed torque data has been used to compare the makeup and breakout torque of individual drillpipe connections. It has also been used to indicate drilling dysfunctions such as stick-slip and improve the understanding of drillstring dynamics. Examples of drilling data will be presented, along with case histories illustrating how this technology improves real-time drilling operations.
Developing the Next Generation of Deepwater Drilling Rig: A Unique Collaboration in Design
Authors: Leary Michael J. , Rettie Stuart D. , Smidth Frederik
Published: March 2015

BP and Maersk Drilling entered into a unique collaborative arrangement in early 2013 to develop the design for a deepwater drilling rig that is specifically aimed at conducting operations on wells with greater than 15,000 psi pressures. This paper describes how this collaborative effort was conducted. Operator and contractor each contributed expertise and information to the project and defined a joint vision of transforming how functional requirements are set and how the design of this rig would be developed. A set of relationship principles was agreed and a joint project team was formed in Houston with engineering support from contrator's technical organization in Copenhagen. An executive committee, with senior leadership from each organization, was established to provide guidance, challenge and governance. To start the design process, workflow during the well construction process was layered on top of the foundational requirements of operator's prospect inventory. Starting with a cleaner sheet of paper, the integrated team's conversations focused on inherently safer design and improving operability, efficiency, maintainability and reliability. The initial focus was on innovation and possibilities before driving toward agreement on the functional specification and rig design. The team strove to address challenges faced in the deepwater drilling industry today, at the same time continually testing their ideas for benefit. After more definition work, the opportunities were run through a detailed evaluation model to inform selection of design features and potential equipment suppliers.

Major equipment suppliers and operator service companies have assisted with the development of rig functional requirements and the shipyard specification. Operator and contractor contributed their learning from previous rig builds, intakes and operation including five and ten year re-certifications into the design. Supplier selection for long lead technology development and qualification of equipment commenced in 2013 and is expected to culminate with a yard selection in 2015.

As a result of this collaboration, operator and contractor better understand the needs and drivers of each other's business and have leveraged this knowledge into a more effective working relationship. Significant work remains to construct the rig and deliver it into operation. However, there is a strong belief this next generation deepwater drilling rig will provide enhanced capability, performance and value to both operator and contractor.
For Better or Worse: Applications of the Transfer Matrix Approach for Analyzing Axial and Torsional Vibration
Authors: Shor Roman J. , Dykstra Mark W. , Hoffmann Olivier J. , Coming Matthew
Published: March 2015

The response of the drilling system to axial and torsional vibration inputs has a significant impact on drilling performance. Usually the goal is to minimize dynamic response to limit the effects of potentially damaging phenomena in the low frequency range (e.g. bit bounce and torsional stick-slip) and high frequency range (e.g. axial chatter and torsional resonance). However, in some cases the goal is to maximize dynamic response, for example when introducing oscillation tools to overcome wellbore friction while directional drilling or to free stuck pipe. Whether the intention is to maximize or minimize, a suitable mathematical model is required. The model presented in this study uses the transfer matrix approach to predict how a harmonic vibration input propagates through the remainder of the drillstring. Novel features of the model include the ability to place the excitation source anywhere in the drillstring and to estimate damping effects due to Coulomb friction in directional wells.

Model inputs include drillstring and bottom hole assembly composition, well survey data, surface equipment and drilling parameters. Drillstring components are modeled as spring or beam elements and the surface equipment is modeled as a mass-spring system. Bit-formation interaction is modeled as a spring, the stiffness of which can be adjusted to provide a boundary condition ranging from fixed to free. Damping due to material hysteresis and interaction with the drilling fluid is modeled using a velocity-dependent term. Coulomb friction is modeled as an equivalent viscous damping coefficient. A harmonic excitation is specified at a given location in the drillstring and the responses at other locations in the system are computed via transfer matrices. This approach allows rapid characterization of the axial and torsional response of the drillstring in the frequency domain and may be applied to analyses of induced oscillation, such as from axial oscillation tools (AOTs), or unintended vibration, such as bit bounce.

Case studies show that predicted frequency responses in the axial and torsional domain compare favorably with high sampling rate downhole and surface measurements, respectively. Additional case studies demonstrate how the model has been successfully applied to diagnose and resolve severe axial vibrations while drilling with roller cone bits. Finally, model predictions are compared with downhole acceleration measurements to evaluate effectiveness of axial oscillation tools while drilling with steerable motor systems. Recommended practices for device placement and drillstring configuration are provided based on the findings from these studies.
Novel Workflows and Underreaming Measurements Reduce Risk by Supporting Decision Making
Authors: Rasheed Wajid , Thorogood John , Bernardini Jaime
Published: March 2015

This paper presents novel well construction work-flows and downhole measurements to improve the success rate with close tolerance casing and cementing operations. Drilling engineers routinely “flip the coin” and mentally take the risk of inferred underreaming. Considering the downtime that occurs across the industry such decisions are not sound. So why are they still taken? Routine decision-making shows a preference for riskier options even if safer options are available.

This paper details workflows and operational measurements that lead to safer and more efficient outcomes. The psychology of controlling risk in decision making is extensively discussed. A recommendation is made for a controlled workflow incorporating ‘gates’ to break routines. This supports the drilling engineer to consciously focus on a key operational gate that is a cause of downtime or operational risk. Critically, this ensures riskier decisions based on inferred underreaming are challenged and gated before sequential well construction activities occur. A further level of support is provided by new downhole measurements. Wellbore diameter is measured using callipers and the downhole status of the underreamer is tracked using magnetic position sensors. Preferential work-flows incorporate these measurements and consequently operations such as the following can be managed more effectively: Running casing/cementing. Check final underreamed wellbore diameter. This reduces the risk of casing getting stuck or an out-of-spec cement job.Underreaming across a section or a trouble zone subject to radial shrinkage or hard stringers. Check wellbore diameter and verify underreamer status. This can trigger a repeated cycle of expansion and check effective deployment of the cutters and the status of the cutters. If cutters have extended yet calliper is below gauge this can indicate a radially- shrinking formation with time or cutters worn or missing.Activating a near bit-reamer. Check wellbore diameter and verify underreamer status across the section to ensure satisfactory underreaming of the section. This ensures the rat-hole is enlarged only when the section is at the predetermined hole size or any remedial work has been completed. This reduces the risks associated with rat-hole enlargement.Activate a secondary redundant reamer. Check wellbore diameter and verify underreamer status. This saves a trip to replace a worn underreamer and avoids premature or unnecessary activation.If cutters are extended yet calliper data shows undergauge then the cutters are worn or missing. Operational parameters such as flow, torque, weight etc can also be monitored and correlated.

The paper concludes with a discussion and statistical analysis of risk factors that can be controlled using the work-flows and operational measurements.
Innovative Product Concepts and Drilling Practices Improve Bit and Reamer Performances in Harsh Drilling Environments
Authors: Mensa-Wilmot Graham , Gagneaux Jay , Woldtvedt Gust
Published: March 2015

Hole opening with bit and reamer, continues to receive attention in the drilling industry (Meyer-Heye, et al, 2010), due to the operation's numerous advantages. In comparison to conventional (single diameter) drilling, hole opening bottom hole assemblies (BHAs), are more complicated, in terms of their design and operation. The presence of two cutting tools, bit and reamer, in hole opening BHAs present additional drilling dynamics challenges (Heisig, et al, 1998). As a result of these issues, hole opening applications are commonly plagued by the following shortfalls – shorter BHA runs, excessive vibrations (Fear, et al, 1997), downhole tool failures, poor borehole quality, lower rate of penetration (ROP), and compromised directional performance (Mensa-Wilmot, et al 2014). These challenges, which have drastic negative effects on operational costs, amplify in harsh drilling environments (Mensa-Wilmot, et al, 2001).

The above issues must be addressed, to ensure cost trend reversals in hole opening applications. This objective requires solutions that focus on the challenges at their sources of initiation. Most important the solutions must ensure consistent and continuous gains in performance. This paper will present new concepts in hole opening, with regards to project analysis, planning, and execution. The discussions will identify and resolve specific hole opening challenges, with emphasis on harsh environment drilling applications. Field cases with supporting data, highlighting the impact of new solutions on project cost reductions, will also be presented.
Innovative Dual-Chamfer Edge Technology Leads to Performance Gains in PDC Bits
Authors: Izbinski Konrad , Patel Suresh G. , VanDeven Alex
Published: March 2015

The dual-chamfer diamond cutter is a new technology combining a primary chamfer with a secondary edge, enabling greater footage to be drilled without compromising rate of penetration (ROP). The average distance drilled in the Mississippi Lime formation was increased by 40% while maintaining comparable ROP to offsets and with significantly improved dull bit conditions, resulting in greater reliability. Since 2013, more than 1, 500 runs with bits utilizing dual-chamfer technology were performed in Oklahoma. The dull state was significantly improved, resulting in reduced incidence of ring outs, core outs and other deleterious bit damage.

The data presented in this paper are based on over 130 laboratory drilling tests. Chip flow analysis was conducted using a unique visual pressurized single-cutter test machine. Full-bit testing was carried out in a pressurized drilling simulator to compare drilling performance. Cutter wear life testing was conducted using an aggressive granite wear test protocol where a 100 to 200% increase in cutter life was documented by edge geometry changes.

Chamfering polycrystalline diamond compact (PDC) cutters has a significant positive effect on edge durability and overall longevity. This concept has not changed over several decades since the introduction of chamfered PDC cutters. Many investigations were conducted with either a singular change to the chamfer height or chamfer angle or with combined edge geometries. These investigations, however, showed only limited success.

The new geometry is based on a thorough understanding of historic investigations and failures observed on how diamond cutter wear flats are formed and degrade. Developments in the drilling sector with greater use of high-power directional motors results in more intermittent off-center drilling with high cutter edge loading. In addition, cutter developments now use leaching methods to reduce cutter wear and better control thermal cyclic loading. A leached diamond layer makes diamond cutters more susceptible to impact damage, resulting in greater premature and catastrophic failures.

For the customer, the improved cutter technology resulted in significant cost savings and more confidence in tool life, enabling greater endurance and durability. Ultimately, the new cutter technology enables lower drilling costs and opens more drilling frontiers that were previously unprofitable.
Achieving Zonal Isolation Using Three-Stage Cementing Systems (An Australian CSG First)
Authors: Zaman Mohammad , Ingram Colin , McLennan Rod , Watt Glenn
Published: March 2015

Regulatory requirements for Coal Seam Gas (CSG) wells in Queensland, Australia dictate that all surface casing strings must be cemented from shoe to surface and all aquifers must be isolated by casing and cement to ensure zonal isolation. A CSG operator drilled a well at an altitude of approximately 500 meters above sea level (m ASL). This altitude is considered high for the area and led to a hydrostatic overbalance across the exposed, permeable Precipice aquifer. The overbalance caused severe to total losses of drilling fluids during the drilling phase. A wide range of conventional lost circulation materials (LCM), light-weight cement formulations and two-stage cement operations were used to mitigate the lost circulation during cementing with limited success.

A three-stage cement job was designed for the 9 5/8 in. (244.5 mm) casing inside 12 1/4 in. (311.1 mm) drilled hole to bring cement around the shoe up to surface across the permeable formations. The casing program utilised 9 5/8 in. (244.5 mm) inflatable casing annulus packers, compatible hydraulic and mechanical stage tools and standard float equipment to create a cement base and cementing flow paths to perform the cementing operations.

This paper will present actual case histories where a three-stage cementing system has been deployed in CSG applications. Proper pre-job planning, detailed procedures and careful attention during on-site execution were key to the success of the multi-stage operation.

By providing a custom solution, the objectives of the operator, the regulatory agencies and the well contractors were met, where other conventional methods had not been successful. We understand this was the first time this application has been applied to Australian CSG wells.
Norg Wells: An Evolutionary Step in Pipe Shearing Technology
Authors: Horstketter R. , Egeraat S. van
Published: March 2015

The capability to produce 12 million m3/day of natural gas requires either multiple conventional wells or two large bore wells using 9-5/8 in. completions. Conventional wells can use a 13-5/8 in. 10, 000 psi BOP Stack. Large bore wells normally require an 18-3/4 in. 10, 000 psi BOP Stack, and a drilling rig of sufficient size to accommodate it. This results in a significant difference in cost per well between drilling conventional wells and drilling large bore wells.

In the summer of 2013, a 13-5/8 in. 10, 000 psi BOP shearing system was in development with tandem piston hydraulic actuators that can utilize up to 5, 000-psi hydraulic operating pressure, generating over one million pounds of shearing force, and shear rams designed for more efficient and robust shearing. A shear-only version of the system could be available in March 2014, provided that the system met the equirements for the Norg wells. For evaluation purposes, a shearing demonstration was conducted on the most challenging pipe sizes planned for the Norg wells.

The exercise demonstrated that the system is capable of meeting the pipe shearing requirements. Accordingly, well control protocols were developed based on the capabilities and limitations of the shear-only system. Through knowledge of the development of the new shear system, the operator was able to make use of the system in establishing the Norg gas storage and production wells. The operator was thus able to accomplish their goal with two large-bore wells instead of three smaller ones, at substantial cost savings.
Potassium Fertility Effects Yield Components and Seed Potassium Concentration of Determinate and Indeterminate Soybean
Authors: Parvej Md. Rasel , Slaton Nathan A. , Purcell Larry C. , Roberts Trenton L.
Published: March 2015

Indeterminate maturity group (MG) IV soybean [Glycine max (L.) Merr.] cultivars may be more susceptible to yield loss from K deficiency due to the shorter growing season and earlier onset of reproductive growth than MG V determinate soybean cultivars. Our objective was to identify whether indeterminate MG IV or determinate MG V soybean are affected differently by K deficiency. Seed yield and selected yield components were evaluated from a determinate (MG 5.3) and indeterminate (MG 4.7) soybean cultivar grown under three K fertility levels (low, medium, and high). The trial was conducted in long‐term plots that receive 0, 75, or 150 kg K ha−1 yr−1. Yield and yield components of both the determinate and indeterminate cultivars responded similarly to K deficiency. Seed yield for soybean grown with low K averaged 3.4 Mg ha−1 and was 13 to 15% lower than the yields of soybean grown with medium and high K fertility. The yield loss associated with K deficiency was from fewer pods (16–25%) and seeds (22–30%) plant−1, higher seed abortion (5–7%), and lower individual seed weight (8–10%) than soybean with medium or high K fertility. Seed K concentration increased with each increase in K fertility level averaging 15.8, 18.7, and 19.8 g K kg−1 for soybean grown under low, medium, and high K levels, respectively. Regardless of growth habit, the yield loss caused by K deficiency was attributed to the same primary mechanisms of reduced pod number and increased seed abortion.
Toward a Selection of Broadly Adapted Germplasm for Yield Stability of Hybrid Rye under Normal and Managed Drought Stress Conditions
Authors: Haffke Stefan , Wilde Peer , Schmiedchen Brigitta , Hackauf Bernd , Roux Steffen , Gottwald Marlen , Miedaner Thomas
Published: March 2015

Climate change will have an influence on crop production and lead to a focus on stable and high‐yielding varieties in breeding programs. Winter rye (Secale cereale L.) is an important crop in Central and Eastern Europe, especially in marginal environments where varying weather conditions have a strong impact on grain yield. Because these environments are the first to suffer from abiotic stress, yield stability is an important breeding goal for rye. The objectives were to evaluate phenotypic diversity for genotype by irrigation interaction (GII) and the potential of hybrid rye to combine high yield potential with superior yield stability. Two intrapool and one interpool population with each of 218 to 220 testcross progenies were grown in a total of 16 to 18 environments (location by year combinations). In six of these environments, managed drought stress trials (rainfed vs. irrigated) were conducted. We observed a wide range of grain yield, from 4.9 to 11.5 Mg ha−1. In the managed drought stress experiments yield reduction in the rainfed regime ranged from 2 to 41% with an average of 18%. Only in a few environments did significant GII occur, although in most environments yield reduction was significant. Genotypic correlations of grain yield between irrigated and rainfed regimes were generally high (0.8–1.0). The coefficient of linear regression (bi) was not significantly different from 1 among progenies. Mean square deviation from linear regression (S2di), however, varied significantly (P < 0.01). To ensure broad adaptability of germplasm, managed drought stress environments should be included in test environments, but they need no special selection procedures. In conclusion, modern rye breeding material already combines high yield potential and stability.
Towards Retrieving Soil Hydraulic Properties by Hyperspectral Remote Sensing
Authors: Babaeian Ebrahim , Homaee Mehdi , Montzka Carsten , Vereecken Harry , Norouzi Ali Akbar
Published: March 2015

In this study, we developed spectrotransfer functions (STFs) that relate soil hydraulic properties (SHPs) to spectral reflectance values to estimate hydraulic parameters of the Mualem–van Genuchten (MvG) model. We investigated the general potential of airborne as well as space‐borne remote sensors to retrieve MvG hydraulic parameters of a bare soil agricultural field. Based on the ASD full spectrum (Scenario I), simple spectral signatures were generated mimicking the hyperspectral EnMAP sensor (Scenario II), and the multispectral Sentinel‐2 sensor (Scenario III). A stepwise multiple linear regression method was used for each scenario to derive STFs. We further tested laboratory‐ and soil‐map‐based HYPRES and Rosetta pedotransfer functions (PTFs) to parameterize MvG parameters and thus provide soil water characteristics and hydraulic conductivity functions in the region. The best results were obtained for Scenarios I and II, with similar R2 values for shape parameters α* and n and the lognormal saturated hydraulic conductivity (Ks*). The R2 values were highest for Ks* in Scenarios I and II (0.58 and 0.57, respectively). The R2 values for α* and n were 0.30 and 0.34 in Scenario I and 0.39 and 0.31 in Scenario II, respectively. In all scenarios, the lowest R2 values were obtained for saturated water content (θs), with values around 0.10 for Scenarios I and II and almost zero in Scenario III. Compared with HYPRES and Rosetta PTFs, the spectral approach performed reasonably well in terms of predicting soil water retention characteristics and unsaturated hydraulic conductivity. These findings suggest that spectral reflectance data provide a promising indirect and quick method for large‐scale parameter estimation.
Seasonal and Interannual Variability of the Effective Flow Cross‐Sectional Area in a Water‐Repellent Soil
Authors: Rye C.F. , Smettem K.R.J.
Published: March 2015

By limiting infiltration and facilitating preferential flow, water repellency in surface soils produces wetting patterns that differ substantially from those in comparable wettable soils. Seasonal variation in water repellency usually follows a pattern of breakdown during periods of persistent rainfall and reestablishment during dry periods, complicating the prediction of moisture partitioning processes at affected sites. To examine the influence of annual water repellency variation on soil moisture, 20 Simple Soil Moisture Probe (SISOMOP) moisture sensors were installed horizontally at depths of 5 and 15 cm at a highly water‐repellent Banksia woodland reserve in Western Australia, recording soil moisture contents during a 42‐mo period from 2010 to 2013. Stages of water repellency breakdown were quantified in terms of the effective cross‐section (ECS) metric, which indicates the relative area share of flow pathways responsible for 90% of the total flow across a horizontal plane at a specified depth. The ECS data showed a steady spread of flow pathways throughout wet winter months of all years on record, consistent with a gradual breakdown of water repellency, usually reaching a maximum state between July and September. The reestablishment of sufficient water repellency to recreate persistent flow paths of low ECS was found to require a prolonged period of some months of hot, dry weather. Summer rainfall was found to be a significant factor in determining the degree of reestablishment during the warmer months, with a year preceded by an unusually wet summer leading to more rapid breakdown of non‐wetting behavior during the following winter.
Options and limitations of hydrogen peroxide addition to enhance radical formation during ozonation of secondary effluents
Authors: Hübner U. , Zucker I. , Jekel M.
Published: March 2015

The oxidation of secondary effluent with ozone and O3/H2O2 (peroxone) was evaluated in batch experiments as pre-treatment for soil aquifer treatment for non-potable reuse purposes. The addition of hydrogen peroxide improved the reduction of ozone-resistant compounds with an optimized radical formation at 0.5 mol H2O2/mol O3. However, the improvement of radical formation was shown to be limited to approximately 30–40% independent from ozone dosage. Also a preozonation step did not accelerate efficiency of subsequent peroxone treatment. Thus, other treatment options, such as an increase of ozone dosages, need to be considered for more efficient removal of ozone-resistant compounds. However, the peroxone process might still be a promising option for oxidation of bromide containing effluents, since a reduction of bromate formation can allow the application of higher ozone dosages.
Adaptive mobile visualization - the chameleon framework
Authors: Pombinho Paulo , Carmo Maria , Afonso Ana
Published: March 2015

The evolution of mobile devices and the development of high speed wireless
networks have supported a widespread use of these devices with increasingly
more complex applications. This reality has fostered the research in the
field of information visualization in mobile devices. However, the limited
screen space, resource constraints and interaction restrictions impose
difficulties to developers and users of these applications. An approach to
address these problems is to adapt the visualization to the user context.
However, these proposals are normally designed in an ad-hoc fashion and are
difficult to generalize. In addition, existing solutions are focused only in
some subset of possible characteristics of the user context or only address a
very specific domain and related adaptations. The objective of this paper is
to present the design of a framework for adaptive mobile visualization (AMV)
applications, denominated Chameleon, and the development and evaluation of
prototypes that use this conceptual-based framework.
EUR/RSD exchange rate forecasting using hybrid wavelet-neural model: A case study
Authors: Bozic Jovana , Babic Djordje
Published: March 2015

In this paper, we examine and discuss modeling and prediction results of
several exchange rates, with main focus on EUR/RSD, using a combination of
wavelet transforms, neural networks and statistical time series analytical
techniques. We have also designed a user friendly software prediction tool in
MATLwhich implements the proposed model. The analyzed hybrid model
combines the capabilities of two different wavelet transforms and neural
networks that can capture hidden but crucial structure attributes embedded in
the exchange rate. The financial time series is decomposed into a wavelet
representation using two different resolution levels. For each of the new
time series, a neural network is created, trained and used for prediction. In
order to create an aggregate forecast, the individual predictions are
combined with statistical features extracted from the original input.
Additional to the conclusion that the increase in resolution level does not
improve the prediction accuracy, the analysis of obtained results indicates
that the suggested model sufficiently satisfies characteristics of a
financial predictor.
Antimicrobial and anticancer evaluation of a novel synthetic tetracyclic system obtained by Dimroth rearrangement
Authors: Gomha Sobhi , Abbas Ikhlass , Elneairy Mohamed , Elaasser Mahmoud , Mabrouk Bazada
Published: March 2015

A series of pyrido[3',2':4,5]thieno[2,3-e][1,2,4]triazolo[4,3-c]pyrimidines
were prepared via oxidative cyclization of 4-(2-arylidenehydrazinyl)pyrido
[3',2':4,5]thieno[3,2-d] pyrimidines. Dimroth rearrangement of such a series
yielded pyrido[3',2':4,5]thieno[2,3-e][1,2,4]triazolo[1,5-c]pyrimidines. The
reaction mechanism was proposed and the products were screened for their
antimicrobial and anticancer activities. From the antimicrobial screening
results, it can be seen that compounds 8c, 9f and 10c showed excellent
activity against gram positive bacteria while compounds 10d and 8c showed the
highest activity against gram negative bacteria. The results of the
anticancer activities showed that compound 9c was the most active against
HepG-2 and MCF-7 with IC50 values of 1.19 and 3.46, respectively.
Comments of the Auditing Standards Committee of the Auditing Section of the American Accounting Association on IESBA Consultation Paper: Improving the Structure of the Code of Ethics for Professional Accountants
Authors: Gaynor Gregory B. , Janvrin Diane J. , Pittman Marshall K. , Pevzner Mikhail B. , White Lourdes Ferreira
Published: March 2015

Recently, the International Ethics Standards Board for Accountants (IESBA) solicited public comments on its Consultation Paper, Improving the Structure of the Code of Ethics for Professional Accountants. This commentary summarizes the contributors' views on the various questions asked in the IESBA Consultation Paper. Our comments submitted to IESBA appear below.

Data Availability: The invitation to comment (which invited comments through February 4, 2015), with links to the consultation paper, is available at: http://www.ifac.org/publications-resources/improving-structure-code-ethics-professional-accountants/.
Cardiorespiratory Fitness and Incident Diabetes: The FIT (Henry Ford ExercIse Testing) Project
Authors: Juraschek Stephen P. , Blaha Michael J. , Blumenthal Roger S. , Brawner Clinton , Qureshi Waqas , Keteyian Steven J. , Schairer John , Ehrman Jonathan K. , Al-Mallah Mouaz H.
Published: March 2015

OBJECTIVE

Prior evidence has linked higher cardiorespiratory fitness with a lower risk of diabetes in ambulatory populations. Using a demographically diverse study sample, we examined the association of fitness with incident diabetes in 46,979 patients from The Henry Ford ExercIse Testing (FIT) Project without diabetes at baseline.

RESEARCH DESIGN AND METHODS

Fitness was measured during a clinician-referred treadmill stress test performed between 1991 and 2009. Incident diabetes was defined as a new diagnosis of diabetes on three separate consecutive encounters derived from electronic medical records or administrative claims files. Analyses were performed with Cox proportional hazards models and were adjusted for diabetes risk factors.

RESULTS

The mean age was 53 years with 48% women and 27% black patients. Mean metabolic equivalents (METs) achieved was 9.5 (SD 3.0). During a median follow-up period of 5.2 years (interquartile range 2.6–8.3 years), there were 6,851 new diabetes cases (14.6%). After adjustment, patients achieving ≥12 METs had a 54% lower risk of incident diabetes compared with patients achieving <6 METs (hazard ratio 0.46 [95% CI 0.41, 0.51]; P-trend < 0.001). This relationship was preserved across strata of age, sex, race, obesity, hypertension, and hyperlipidemia.

CONCLUSIONS

These data demonstrate that higher fitness is associated with a lower risk of incident diabetes regardless of demographic characteristics and baseline risk factors. Future studies should examine the association between change in fitness over time and incident diabetes.
Comparative Analysis of Quality-of-Life Metrics after Endoscopic Surgery for Sinonasal Neoplasms
Authors: Deckard Nathan A. , Harrow Brian R. , Barnett Samuel L. , Batra Pete S.
Published: March 2015

Background

The objective of this study was to evaluate the postoperative quality of life (QOL) after endoscopic resection of sinus and skull base neoplasms using validated outcomes measures and to perform correlation of the various metrics to better discern their efficacy. Prospective QOL data collection and retrospective chart review were performed.

Methods

QOL data were collected using the 20-item Sino-Nasal Outcome Test (SNOT-20), Anterior Skull Base Questionnaire (ASBQ), European Quality-of-Life-5 Dimension (EQ-5D) questionnaire, and Lund-Kennedy endoscopic (LKE) score in 71 patients with sinonasal and skull base tumors.

Results

The mean age was 53 years and mean follow-up was 14.5 months at the time QOL data were collected. Benign and malignant tumors represented 39 (54.9%) and 32 (45.1%) cases, respectively. Twenty malignancies (62.5%) were stage T3 or T4, and 23 required postoperative chemotherapy and radiation (CRT). Factors indicating worsened postoperative QOL included malignant histopathology, T3 or T4 tumors, and the use of postoperative CRT (p < 0.05). There was a strong correlation of ASBQ with EQ-5D and SNOT-20 scores (r < -0.5) and a moderate correlation between the SNOT-20 and EQ-5D (r > 0.3), and the LKE had moderate correlation with SNOT-20 (r > 0.3) and weak correlation to the ASBQ (r > -0.3) and EQ-5D (r < 0.3).

Conclusion

Patients who have undergone endoscopic resection of sinonasal tumors have quantifiable QOL changes as measured by various validated metrics. This study shows that concurrent use of these instruments may better discern QOL outcomes after endoscopic tumor surgery.