bluuebunny/crossref_metadata_2025 huggingface dataset:
Subsea Cable Applications in Offshore Oilfield Facilities
Authors: Liang Xiaodong , Stevens John , Kelly Dwayne
Published: September 2013

The increase in use of variable frequency drives (VFDs) in oilfield facilities, especially for some offshore platforms, often leads to a significant percent of VFDs in total load demand. The VFDs provide many advantages for facility operation, but also produce harmonic contents to electrical power systems. Subsea cables are widely used in offshore power distribution systems. There are two typical applications for subsea cables: 1) transmitting power from the power generation to loads on remote platforms (involving line-side harmonics of a VFD); 2) transmitting power from the output of a VFD to remote electrical submersible pump (ESP) systems (involving load-side harmonics of a VFD). The combination of VFDs and subsea cables in power systems could introduce harmonic resonance, which, if not properly mitigated, amplify certain harmonics and cause significant damage to the electrical equipment in the facilities.

An investigation was conducted for the two typical applications in offshore oilfield facilities considering harmonic resonance conditions. The first application involved parallel harmonic resonance and line harmonics, which will amplify harmonic currents. The second application involved harmonic resonance and load harmonics, which will amplify harmonic voltages. Computer simulation software programs were used to develop solutions using line-side and load-side harmonic filters to mitigate harmonics and attenuate resonance; these solutions were verified to be effective in case studies
From Schiehallion to QUAD 204 FPSO, Turret Mooring System Experience and Enhancements
Authors: Fromage Lionel , Fournier Jean-Robert , Drijver Pieter , McLeary Alwyn
Published: September 2013

The Schiehallion Floating Production Storage and Offloading (FPSO) is moored by a Turret Mooring System (TMS) located in 400m water depth in the Atlantic Frontier and submitted to very challenging environmental conditions. The Schiehallion FPSO went on stream in 1998. As part of the planned field development the QUAD 204 FPSO currently under construction will replace the producing unit in 2015. In both cases, SBM Offshore (SBMO) is the supplier of the Turret Mooring System. This paper compares the main features of Schiehallion and QUAD 204 TMS: mooring lines, connectors, weathervaning system, manifold and swivel stack arrangement. The performance of the key components over 15 years of operation is reported. The changes brought to the original design are highlighted and discussed.
Umbilical Lay in Challenging Environmental Conditions
Authors: Gueret Renaud , Lahiri Subhajit
Published: September 2013

Total E&P UK Ltd and partners DONG E&P (UK) Ltd are developing the Laggan & Tormore gas fields which are located in approximately 600 metres water depth in Blocks 206/1a, (P911) and 205/5a (P1159) respectively situated approximately 125km north west of the Shetland Islands on the UK Continental Shelf.

As part of this development, in summer 2012, Subsea 7 installed a 127 km long umbilical between the landfall at Shetland Islands and Laggan manifold. It consisted of a bundle arrangement, including two-way fibre optic communication, high voltage electricity supply, chemical supply and hydraulic power.

The installation was particularly challenging as it consisted of laying a low density product (127mm diameter, 10.6kg/m submerged weight) along a route with particularly high currents and a large range of water depths [20m–600m].

Consequently, large umbilical deflections were expected and a Subsea Depressor Device (SDD) was devised to aid installation and act as a ballast to weigh down the catenary and oppose current. It was made of a weight element with a bellmouth funnel opening on each side through which the umbilical ran and was suspended from a deck winch. The wire length was tuned to control the SDD height above seabed.

This paper details the equipment used for this challenging operation and the lay strategy that was devised for laying the umbilical in various water depths and current conditions.

Special attention was paid to securing the umbilical should the vessel weather a storm. A lazy S-wave configuration obtained with floats connected to the umbilical was devised for this purpose and has been described in the paper.
Integration and Assurance of Well Documents and Data – Essential Preparation for Tomorrow
Authors: Sawaryn S. J. , Pirie L. , Green I. , Scott A. , Cosgrove B. , Emslie I.
Published: September 2013

During the last four years over 330,000 electronic drilling, completions and interventions documents have been consolidated in a new document management system, improving both their accessibility and future worth to the expanding user base. The system’s document structure builds on earlier, engineer-led experience and has contributed to the new company-wide standard for managing these documents. At the same time, the document management project has eliminated over 180,000 duplicate or obsolete documents.

As part of the migration from the old system to the new one, common well names have been adopted to support integration activities both within the Wells function and also with the Subsurface and Operations communities. Directional surveys are key links between these communities and over the same period, an in-depth, field by field review of the company’s UK directional survey data has been conducted. This activity is now approximately 67% complete. Together, these activities are seen as essential preparations for the future and they have already helped streamline some activities in both asset acquisitions and disposals.

These tasks have taken time, but measured preparation plus a degree of pragmatism have ensured they remain manageable. Care has been taken to maintain the document folder structure so it remains familiar to users, whilst taking advantage of the superior capabilities, such as search and assurance available in the new system. The paper contains an outline of the structure, metadata and a description of the project’s goals and history, including some of the challenges commonly encountered in preparing, processing and exporting and importing data. Details of the directional survey data verification process is also provided.

This subject is of interest to many companies because of the scale of the exercise and the growing recognition in the industry of its technical and commercial importance.
Hull Inspection Techniques & Strategies
Authors: Caldwell Raymond
Published: September 2013

As field life extends, managing the hull integrity of a Floating Offshore Installation (FOI) has become more critical. Employing Class entails the hull undergoing a robust five yearly survey cycle to assure its integrity. Part of that cycle includes drydocking the vessel. FOIs tend not to drydock resulting in significant challenges to operators in managing the hull integrity of their floating installations. Consequently, some operators have chosen to extend the concepts of structural integrity management and are seeking to develop new techniques to support risk based inspection of the submerged hull and the internal cargo and ballast tank structure. Inspection techniques and the information obtained therefrom are key parameters in the assessment of structural integrity. But are these parameters well identified? What data is needed to assure hull integrity and how can we best obtain this data?
Corrib Low Temperature Start-up
Authors: Duijts Rainier , Nagle Paul , Smith Charles , Bourdel Sandrine , Levet Alexandre , Mahieu Camille
Published: September 2013

This paper presents the feasibility and concept selection study for the low temperature start-up of the Corrib Project. A number of diverse options were studied and their feasibility determined, but significant attention is given to the selected option which involved qualifying flexible flowlines to lower temperatures than previously were available, and to the second option, which involved the specification of a bespoke subsea warming spool pyramid structure.

The Corrib project has been ongoing for a number of years and is, at present, in the execution phase with first gas estimated late 2014 / early 2015. A number of changes are required for the ability to start-up the production facilities outside the previous operating envelope of -20°C, which was constrained by the flexible flowlines that connect the subsea wells to the manifold. This was required as a result of a number of developments that occurred during 2009 to 2010. The most promising, (a) the low temperature testing and qualification of a flexible flowline, and (b) a low temperature rigid warming spool, were studied and the optimum was selected in the concept selection stage. The newly qualified low temperature flexible flowlines will be installed prior to initial start-up.

Qualification testing of the end fitting design was performed based on the protocol presented in API RP 17B for low volatile content polymer pressure sheaths in order to demonstrate that the integrity of the end fitting sealing mechanism could withstand the potential temperature cycling predicted during service conditions. Mid scale flexible pipe and end fitting specimens were prepared and subjected to thermal cycling between the design temperatures, along with intermediate inspections and pressure tests to monitor for signs of failure initiation as the test progressed. The two specimens tested successfully and returned API RP 17B fully qualified low temperature results to -35°C with one specimen qualified to -45°C.

With the increased use of more rigorous standards on asset integrity and reliability and longer subsea tie-backs, requiring wider pipeline operating envelopes, it is likely that this extended flexible pipe operating envelope will be used in many more future projects.
Critical Buckling Load Assessment Of Drill Strings In Different Wellbores Using The Explicit Finite Element Method
Authors: Hajianmaleki Mehdi , Daily Jeremy S. , Ring Lev , Gandikota Raju
Published: September 2013

Previous theoretical formulations for sinusoidal and helical buckling of drill strings vary significantly and are mostly proposed for frictionless pipes without tool joints. Finite element analysis (FEA) methods have the ability to consider geometric details and large deflections. However, traditional FEA methods use shell or solid dimensional elements for this problem and are computationally expensive. In this paper, an explicit FEA based on beam and connector elements implemented in the Abaqus software is employed to study the buckling of drill strings in different wellbores. The wellbore geometry, stiffness, friction load, and friction induced torque are modeled using connector elements. A typical drill string in vertical, inclined, horizontal, and curved wellbores is simulated and the explicit FEA results for sinusoidal and helical buckling loads are compared to different theoretical formulations and experimental results in the literature. The effects of length, inclination angle and string effective weight due to buoyancy as well as the effect of tool joints in straight and curved wellbores is also studied and compared to present formulations and published experimental results. Overall, it is demonstrated that using explicit FEA can efficiently study drill strings buckling behavior in straight and curved wellbore conditions.
Integrated Marine and Integrity Monitoring of FPSOs in Hostile Environments - The Importance of Observed Data
Authors: Ledgard Louise , Prislin Igor , Johnson Thomas L
Published: September 2013

The design and operation of an FPSO in remote locations requires detailed information on the structural response of the vessel within the local environment offshore. Monitoring of critical components including the risers, hull and mooring lines simultaneously with the local environmental forcing of waves, wind and currents at the site location, provides a valuable insight into the performance and possible extension of the integrity life of the asset.

Verification of the riser and vessel design is often theoretical and actual measured observation of the response of the critical components of an FPSO in the field is less frequent. As new technology is introduced, riser design becomes more sophisticated and extension of design life is required, it becomes increasingly important to monitor an assets performance. In hostile or remote locations where information on the environmental forcing is less known, monitoring becomes critical to assist with operational decisions, forensic investigation and the evaluation of design codes.

This paper will provide a technical overview of an FPSO integrated marine monitoring system located in a hostile environment, typical of West of Shetland. The focus of this paper will be on the marine monitoring system; however an overview of the monitoring of subsea risers and moorings will be included for completeness. A discussion on the importance of monitoring the environment and the structural behaviour on a common time base for integrity management and forensic investigation of marine incidents will be presented.
VRR < 1 Is Optimal for Heavy Oil Waterfloods
Authors: Vittoratos E. , West C. C.
Published: September 2013

Increasingly, the reservoirs remaining to be developed have lower gravity, particularly for the older offshore basins such as the North Sea. Optimal waterflood VRR management will be the key to their economic success. Current industry paradigms and regulatory mandates assume that the light oil practice of complete voidage replacement, VRR = 1, should be continued for the heavy oil reservoirs to be waterflooded. Empirical data, laboratory experiments, and mathematical simulation methods indicate, however, that for heavy oil waterfloods the optimal voidage replacement ratio (VRR) is less than one. Analysis of empirical data from an Alaskan heavy oil reservoir (18 API) show that after water breakthrough, periods of VRR < 1 are important for increased recovery. Laboratory data from an Alaskan heavy oil (12 API) waterflooded in a five foot long ‘big can’ show significantly higher recoveries with VRR < 1. Numerical simulations are directionally in agreement with these empirical & laboratory observations even when only using conventional concepts.

Many more recovery mechanisms are activated with VRR < 1 than with VRR = 1. Some are readily understood with existing conventional concepts. Common geological depositional environments do not permit complete waterflood sweep, and ‘cul de sacs’ of unswept oil are left behind that can only be depleted with the activation of solution gas drive by VRR < 1. Less conventional concepts include the chemical changes that accompany pressure declines, that result in more surface activity and increased in-situ emulsion multiphase flow, which may self-divert to increase waterflood conformance. The numerical simulation of the VRR < 1 process is difficult and only a limited number of the mechanisms can be effectively modeled. Nonetheless, directional trends have been identified.
Fulmar - Increased Production From A Mature Reservoir
Authors: Franck Nathalie , Slater Julian
Published: September 2013

The North Sea is a mature basin that has seen rapid decline during the last decade. This paper illustrates that with the appropriate targeted investment it is possible to arrest this decline and actually increase production from mature assets. The investments have increased recovery from existing fields and coupled with production from adjacent satellite fields, field life has been significantly extended.

Using the Fulmar platform as a case study this paper describes how during 2011 and 2012 production was raised from 3,000 to 15,000 STB/D. This was achieved through a combination of improved uptime, water injection reinstatement, wellwork and bringing online subsea tie backs.

Fulmar is a large oil field located in UKCS block 30/16, and originally contained 822 MMSTB. Production started in February 1982 and reached a plateau rate of 160,000 STB/D. By 2010 the recovery factor had exceeded 65% and oil production had declined to less than 3,000 STB/D.

Operational efficiency has been improved by implementing upgrades that target historical losses. During the second half of 2012, Fulmar export set a record for the longest continuous run in the platform’s history. Water injection has been increased after a 2010/2011 campaign to reinstate four water injection wells and upgrades to the seawater lift pumps and filtration.

The new Auk North satellite field has been tied back to Fulmar using four subsea wells giving over 10,000 STB/D boost to production. The Fulmar 2011/2012 coil-tubing campaign has reinstated three production wells, with the campaign showing that Fulmar still has significant upside potential.

Following the success of the Fulmar well campaign, additional interventions are planned for 2013 to increase production. A new dedicated subsurface team is currently working up infill well targets and a wells project team is actively working to reinstate the Fulmar drilling rig. Despite its maturity Fulmar has a number of near field discoveries and exciting exploration prospects that can continue to boost production volumes into the next decade.
Methods for Community Mapping Using Integrated Biological and Side-Scan Sonar Data
Authors: Gubanova Y. , Isachenko A. , Tokarev M. , Mokievsky V.
Published: September 2013

Nowadays problems of ecological and geotechnical investigations are emphasized on. A lot of scientists both mapping bottom sediments and trying to reconstruct complex, multi-component seabed system, which include biological factors either. For example, geophysical data is successfully used to evaluate contrasting biological objects on the bottom, such as communities associated with seamounts and pock-marks, oyster or mussels banks.

Material for this study was procured during surveys in Kandalaksha bay, the White Sea (Arctic). During 2010 – 2012 side-scan sonar (SSS) and VHR seismic surveys, qualitative sampling, underwater photo and video were carried out at the polygon of study.

Main task of this research was community mapping. Spatial structure of benthic communities shows very high heterogeneity in the area of survey. Thus so, samples can’t be validly interpolated to the area more than 20 m in radius. Knowledge of bottom sediment structure and topography allows obtaining a higher degree of accuracy of community mapping.

Biodiversity is related to bottom sediments type. It’s mean sonar data include information about community. On the other hand, Arctica Islandica shell big (4 cm on the average) and hard enough to backscatter high-frequency acoustic signal. There are two factors which connect community structure and side scan sonar data, this correlation may be defined. Sediments mapping was done by joint interpretation of the seismic, SSS, data of sample grain size and underwater observations.

For research of underwater landscape distribution on the polygon method of mapping was used. It’s based on integrated interpretation of traditional sampling data, underwater observation, photo and video results and remote sensing methods (side scan sonar). Detailed data of underwater landscapes were produced.
The Successful Implementation of a Competency Program in a Large Global Organization: A Case Study
Authors: Leuro Jorge , Kruger Todd
Published: September 2013

Introducing a competency program to an organization, whether new or the latest evolution, requires a structured approach. Each approach typically divides the activities into multiple phases, which are cyclic in nature. Regardless of what the phases are called, in essence, each project lifecycle begins with a "design" phase, followed by an "implementation" phase, and then a "measure and review" phase. The program is then continually fine-tuned though a series of project lifecycles with the intention of delivering the objectives of the program.

Often, program managers overestimate the importance of the "design," underestimate the challenges of "implementation," and overlook the need to track the correct metrics during "measure and review." This reality is highly obvious in programs that demonstrate great potential that have been implemented globally, but are only accepted by a few locations or groups, making it difficult to prove the program’s value.

This paper describes an 11-year journey of introducing a business-driven competency and employee development program within a large global oilfield service company. For each of the five defined periods of evolution, this paper provides details of the approaches taken during each phase of the project lifecycles, all of which contributed to the program’s ultimate acceptance by the organization, its proven influence on superior business results, and its alignment with the latest regulatory requirements.

The purpose of the information presented is to provide practical observations and recommendations that can help assist other organizations with the pursuit to introduce similar programs. Whereas, the evidence provided in this case study directly relates to a competency program, the relevance of the lessons learned can also be applied to other human resource (HR) initiatives.
Use of Sonar Metering to Optimize Production in Liquid Loading Prone Gas Wells
Authors: Shields C. A. , Dollard M. , Sridhar S. , Dragnea G. , Illingsworth M.
Published: September 2013

The East Brae platform is located in UK Block 16/3a and is operated by Marathon Oil U.K. LLC. The platform has a high pressure (HP) separator 406 psig (28 barg) and a test separator operating as a low pressure (LP) production separator 217 psig (15 barg). There are currently 12 producing gas wells; varying water-gas ratios and low gas rates result in liquid loading being a major flow assurance issue. This paper discusses the use of clamp-on sonar flow meters to minimize losses associated with well testing and the subsequent benefits that were seen with respect to production optimization and well deliquification. Clamp-on sonar flow metering is a non-intrusive technology which measures the flow velocity of the fluid stream. Sonar meters have been deployed every two months to facilitate routine production well testing of all wells to meet allocation and field management requirements. Prior to sonar metering, wells capable of only flowing to the LP separator needed to be shut-in to allow individual well tests. Wells can now be individually sonar well tested without production interruption. Different methods have been adopted to optimize production and combat liquid loading. ‘Swing’ wells use the LP separator to unload liquids and thus improve their subsequent performance in the HP separator. Sonar metering determined the optimal cycle frequency for individual wells, allowing Marathon Oil to keep the LP separator full and maintain maximum rates in the HP separator. Wireless wellhead temperature sensors have been recently installed and have been correlated to sonar measured gas rates in the well bore, providing a real-time trend of liquid loading and well performance. Currently 75% of the well stock is cycled every 4 hours in order to optimize production. This intensive well management has assisted in reducing the production decline of the East Brae field.
Case History: First Intelligent Well with Feed-Through Zonal Isolation in a Multilateral Sidetrack Completion in the Troll Field
Authors: Dahle Bjørn Olav , Prebeau-Menezes Leon , Smith Peter E. , Gjelstad Geir
Published: September 2013

The Troll Field is located approximately 80 km northwest of Bergen in the Norwegian Sector of the North Sea around 65 kilometers west of Kollsnes, and is operated by Statoil. The field is comprised of the main Troll East and Troll West structures in blocks 31/2, 31/3, 31/5 and 31/6. Although the field historically had produced large amounts of oil, it is now also a major gas producer, as it contains approximately 40% of total gas reserves on the Norwegian continental shelf. The gas reservoirs that are 1,400 meters below sea level are expected to produce for at least another 70 years. Statoil, wishing to run a deep sidetrack from the mother bore of a multilateral well, decided to evaluate several zonal isolation methods and to combine this with intelligent well completion technology. Since this would be a "first time" Statoil Troll field deep sidetrack from the mother bore in a multilateral well application, regardless of the technology selected, a full scale test to qualify the technology for the application would be required.

After evaluating several zonal-isolation methods, and their previous experiences with isolation concepts, Statoil decided to use a combination of intelligent well completion design with feed-through swellable packer technology. This combination concept would not only be the first intelligent well completion of its kind in the Troll field, it would also be the first ever Statoil use of feed-through swellable packers.

Swelling and differential pressure tests were initiated using oil from the Troll field. The testing revealed that this type of completion exceeded the sought-after requirements for the project. This well design was then approved and installed on a semi-submersible rig without any HSE incidents and ahead of plan. The well was put on production shortly thereafter, and zonal isolation was confirmed by selective closure of the flow control valves. Additionally a second nearly identical completion well design was installed in May 2013.

The paper will discuss the swellable packer design, qualification testing, planning, installation, and the results of the first intelligent completion with feed-through zonal isolation on the Troll Field.
Simulation of Large‐Scale Field Infiltration Experiments Using a Hierarchy of Models Based on Public, Generic, and Site Data
Authors: Wang Wenbin , Neuman Shlomo P. , Yao Tzung‐mow , Wierenga Peter J.
Published: September 2013

Comparative simulations of a large‐scale field infiltration experiment at the Maricopa Agricultural Center (MAC) near Phoenix, AZ, were conducted using a hierarchy of models based on public, generic, and site data joined with pedotransfer functions and an inverse procedure. Our purpose was to investigate the ability of simple models and relatively inexpensive data to reproduce and predict reliably the time evolution of water content profiles in nine 10‐m‐deep neutron monitoring boreholes at the site. By relying solely on public sources of information one might conclude that soil at the MAC site is uniform to a depth of 16 m, with a water table at about 22 m. Upon collecting soil samples at the site, we learned the soils are layered and laterally discontinuous, with a perched water table at about 13 m. To identify the least level of complexity required to simulate infiltration at the MAC, we compared models that consider one‐ and two‐dimensional flow in a uniform soil, a soil consisting of uniform layers, and a stratified soil with laterally distinct zones. There is a paucity of hydraulic characterization data for the site. To investigate the feasibility of obtaining hydraulic parameter estimates for the models on the basis of soil type, we ascribed uniform properties to each layer or zone using mean values of three generic databases. To improve these estimates, we ascribed variable soil hydraulic properties to individual soil samples using regression and neural network pedotransfer functions based on soil type and bulk density; we then used them to obtain Bayesian updates of mean hydraulic properties in each layer or zone. We used the various models and mean parameter estimates to simulate water contents during one of several infiltration experiments at the MAC. None of the results compared well with measured water contents, although one set of generic mean parameter values yielded much better results than the other two. Estimating parameters using pedotransfer functions and Bayesian updating does not lead to improved simulations. Only when the parameters are estimated by means of an inverse procedure does one notice a significant improvement in model fit. We compared and ranked the various models and parameter estimates using likelihood‐based model discrimination criteria and confirmed our choice of best model by successfully simulating flow during an earlier infiltration experiment.
Analysis of Inverse Procedures for Estimating Parameters Controlling Macropore Flow and Solute Transport in the Dual‐Permeability Model MACRO
Authors: Roulier Stéphanie , Jarvis Nicholas
Published: September 2013

Because they are objective and reproducible, inverse modeling procedures are increasingly used to identify model parameters that cannot be easily measured. This study investigated the feasibility of using inverse methods to estimate parameters describing macropore flow, transport, and transformation processes in the dual‐permeability model MACRO. MACRO was linked to the inverse modeling package SUFI, and we used numerically generated data representing transient leaching experiments for tracers and reactive solutes in microlysimeters (21‐cm height). Attention was focused on parameter sensitivity, availability of experimental data (flux and resident concentrations), the degree of macropore flow in the system, and the significance of experimental errors. Reliable results were obtained in the case of strong macropore flow, but both resident and flux concentrations were needed. However, the uncertainty in d, the parameter describing mass exchange between microporosity and macroporosity, remained large, and the adsorption coefficient could not be estimated accurately. Response surface analysis showed that this was due to a lack of sensitivity to d and to internal correlation between adsorption and degradation parameters. In the case of equilibrium flow, the model was overparameterized, and the parameters related to macropore flow were not sensitive enough to be estimated properly. Experimental errors did not affect the feasibility of the procedure, although the uncertainty in the estimates increased. SUFI linked to MACRO appears to be a promising tool for optimization of the system parameters in soils affected by macropore flow, but the “experimental” design needs to be improved for reliable determination of the mass exchange parameter and the adsorption coefficient.
Helium and Neon Groundwater Tracers to Measure Residual DNAPL: Laboratory Investigation
Authors: Divine Craig E. , Sanford William E. , McCray John E.
Published: September 2013

A laboratory investigation was conducted to evaluate the applicability of dissolved He and Ne as partitioning tracers for detecting and quantifying nonaqueous phase liquid (NAPL) in the saturated zone. Based on the results of batch experiments, the equilibrium NAPL–water partition coefficients (KN,W) of these tracers for two common dense NAPLs (DNAPLs), tetrachloroethene (PCE) and trichloroethene (TCE), are: KPCE,W = 1.28 and KTCE,W = 2.42 for He, and KPCE,W = 1.84 and KTCE,W = 3.24 for Ne. Tracer partitioning is linear across the range of concentrations tested, and appears to be linear even near aqueous solubility limits of the gases. Multiple partitioning tracer tests (PTTs) were conducted in columns, and residual TCE saturations (STCE) ranging from 4.7 to 10.5% were successfully measured by the tracers. Sensitivity analysis for the column experiments indicates that random tracer‐measurement error of up to ±20% had little effect on results; however, accurate characterization of the tail region of the tracer curves is particularly important. Therefore, the low analytical detection limits possible with dissolved He and Ne (4 to 5 orders of magnitude below aqueous solubility) may permit better tracer curve characterization than commonly used alcohol partitioning tracers, and is a notable advantage for these tracers. Due to their high Henry's Law constants, these gases will also partition into trapped air present in the tracer sweep zone. Equations are presented for estimating both trapped air and NAPL saturation for PTTs where three phases are present (water, trapped air, and residual NAPL). The results of this investigation provide a basis for field‐scale application of dissolved He and Ne as groundwater partitioning tracers.
Laboratory Evaluation of the Dual‐Probe Heat‐Pulse Method for Measuring Soil Water Content
Authors: Basinger J. M. , Kluitenberg G. J. , Ham J. M. , Frank J. M. , Barnes P. L. , Kirkham M. B.
Published: September 2013

The dual‐probe heat‐pulse (DPHP) method provides a means of estimating volumetric soil water content (θ) and change in volumetric water content (Δθ) from measurements of volumetric heat capacity. The purpose of this investigation was to characterize the accuracy and precision that can be achieved in measuring θ and Δθ with the DPHP method. Tempe pressure cells fitted with DPHP sensors were used to conduct desorption experiments in which DPHP‐based estimates of θ and Δθ were compared with values estimated by the gravimetric method. For water contents corresponding to soil water pressure potentials below −100 kPa, comparisons were made by packing the pressure cells with soil wetted to known water contents. The investigation was conducted with seven soil materials representing a wide range of physical properties for mineral soils. The DPHP sensors slightly overestimated θ at low water contents, but it was shown that the bias could be removed by using an empirical calibration equation, θ = 1.09 θDPHP − 0.045. This relationship appears to be general inasmuch as it was shown to be applicable for all seven soil materials and for water contents ranging from 0.02 to 0.59 m3 m−3 The general calibration equation was also shown to be effective in removing bias in Δθ estimates. Pooled regression analysis (all soil materials) showed that θ can be measured with a root mean square error (RMSE) of 0.022 m3 m−3 Greater precision can be achieved with Δθ measurements (RMSE = 0.012 m3 m−3); however, the results indicated a decrease in precision with increasing magnitude of Δθ.
A Sensitivity Analysis of Electrical Resistivity Tomography Array Types Using Analytical Element Modeling
Authors: Furman Alex , Ferré Ty P. A. , Warrick A. W.
Published: September 2013

The analytic element method is used to investigate the spatial sensitivity of different electrical resistivity tomography (ERT) arrays. By defining the sensitivity of an array to a subsurface location we were able to generate maps showing the distribution of the sensitivity throughout the subsurface. This allows us to define regions of the subsurface where different ERT arrays are most and least sensitive. We compared the different arrays using the absolute value of the sensitivity and using its spatial distribution. Comparison is presented for three commonly used arrays (Wenner, Schlumberger, and double dipole) and for one atypical array (partially overlapping). Most common monitoring techniques use a single measurement to measure a property at a single location. The spatial distribution of the property is determined by interpolation of these measurements. In contrast, ERT is unique in that multiple measurements are interpreted simultaneously to create maps of spatially distributed soil properties. We define the spatial sensitivity of an ERT survey to each location on the basis of the sum of the sensitivities of the single arrays composing the survey to that location. With the goal of applying ERT for time‐lapse measurements, we compared the spatial sensitivities of different surveys on a per measurement basis. Compared are three surveys based on the typical Wenner, Schlumberger, and double dipole arrays, one atypical survey based on the partially overlapping array, and one mixed survey built of arrays that have been shown to be optimal for a series of single perturbations. Results show the inferiority of the double dipole survey compared with other surveys. On a per measurement basis, there was almost no difference between the Wenner and the Schlumberger surveys. The atypical partially overlapping survey is superior to the typical arrays. Finally, we show that a survey composed of a mixture of array types is superior to all of the single array type surveys. By analyzing the spatial sensitivity of the single array, and most significantly the sensitivity of the ERT survey, we set the basis for quantitative measurement of subsurface properties using ERT, with applications to both static and transient hydrologic processes.
A Case of Erosive Polyarthritis in a Patient Diagnosed With a Suspicion of Atypical Mycobacteria
Authors: Almoallim Hani , Alharbi Laila , Alshareef Zainab , Wali Ghassan
Published: September 2013

In this report, we introduce a case of erosive polyarthritis in a 55-year-old female diagnosed withMycobacterium abscessuspulmonary infection. Her arthritis has been worsened after use of DMARDs. The patient demonstrated a significant response to the antimicrobial regimen that was administered. We call special attention to the possibility ofMycobacterium abscessusbeing a cause of reactive polyarthritis, particularly if symptoms worsened after use of disease-modifying antirheumatic drugs (DMARDs), but further studies are necessary for clarification.
Pre-Collection of Domestic Waste in Slum Districts of Yaoundé in
Cameroon: Socio-Economic and Sanitary Impact
Authors: Emmanuel Ngnikam , Emile Tanawa , Benoît Mougoue , Pierre Etoga Simon
Published: September 2013

In developing countries, the management of solid waste constitutes one of the main challenges of the present
decade. A pre collecting pilot operation taking solid waste from individual households to municipal bins was implemented
at Melen in Yaounde.

The methods used for the preparation of this operation included meetings between project partners to agree on project
objectives and implementation, the identification and interviewing of key actors, conducting a population census and an
assessment of the waste generating activities in the targeted area, documenting research, meetings for information sharing
and discussion with the inhabitants and the mapping of potential waste collecting itineraries in the targeted areas.

By the end of the first year of investigation, we identified the actors of waste management and the services they offered,
identified the youth associations capable of waste collection process implementation, and assessed the population’s ability
to finance collection the cost of which varied between US$1.25 and US$5 per month. In addition, we noticed that 81% of
the households were ready to pay for the pre collection of their waste. The project team endeavoured to create an
environment that supported dialogue among various actors enabling follow-up and supervision of the process on the field.
The assessment of the first 5 years of the waste program has proven the commitment of the inhabitants to participate in
this type of operation through the direct payment for the service: 40 % of the targeted households continued to pay for the
pre collection service. The total contribution collected is about US$7,750 per year that permits the employment of 8
persons.

This operation collected 22.4 tons of waste per month between 2002 and 2007, waste that would have been otherwise
thrown into the streams, directly improving the environment and the population's health in these quarters.
Endothelin Receptor Antagonists (ERA) in Hypertension and Chronic
Kidney Disease: a Rose with Many Thorns
Authors: M Doumas , V Athyros , N Katsiki , A Reklou , A Lazaridis , A Karagiannis
Published: September 2013

The discovery of endothelin created a lot of enthusiasm and paved new therapeutic avenues for the treatment
of arterial hypertension. Endothelin plays a significant role in blood pressure regulation through pronounced vasoconstriction
and modulation of sodium and water reabsorption in the kidneys. Endothelin receptor antagonists have been tested in
many clinical trials in patients with arterial hypertension, heart failure, pulmonary arterial hypertension, systemic sclerosis,
chronic kidney disease, and diabetic nephropathy. However, the results were usually disappointing, except in pulmonary
hypertension and scleroderma digital ulcers. The future of ERAs for the treatment of arterial hypertension and
chronic kidney disease does not seem bright, and only the combination with other classes of antihypertensive drugs might
offer a way out.
Comparing Spontaneous Imitation in Grandmother-Infant and Mother-Infant Interaction: A Three Generation Familial Study
Authors: Kokkinaki Theano , Vitalaki Elena
Published: September 2013

The aim of this longitudinal and naturalistic study was to compare aspects of imitative exchanges in dyadic grandmother-infant and mother-infant interactions. Sixteen Cretan Greek infants were video-recorded in the course of spontaneous dyadic interactions with maternal grandmothers or with mothers at home from the 2nd to the 10th month of their life ( N = 48). The present study provides evidence that in interaction between grandmothers and infant grandchildren and between mothers and infants, there is similarity in the frequency, the structure, the direction of imitation, the kind of imitated acts, and the temporal patterns of the components of imitation. Infants' age was found to affect the developmental curve of grandmothers‘, but not mothers’, imitative behavior. In the frame of the theory of innate intersubjectivity, we assume that similarity in these aspects of imitation may be related to invariant fundamental dimensions of Significant Other-infant communication (“kinematics” (temporal patterns), “physiognomics” (forms) and “energetics” (effort)). These similarities may have implications for both grandmothers' and infants' ability to regulate interpersonal challenges within an extended-family interactional context.
Cultures of the east (1984-1992)
Authors: Pajin Dusan
Published: September 2013

The quarterly journal, Cultures of the East (1984-92), was founded with the
intention of presenting Near and Far East cultures to academics, as well as a
wider audience, and illuminate some of its rich cultural heritage. The
subtitle defined the journal as a ?journal for Eastern philosophy, literature
and art?. However it also contained other issues, such as religion. Some
issues had a comparative approach, compiling studies (on philosophy,
religion, etc.) of Eastern as well as Western origin on a given topic.
Recently two digital internet presentations of the journal issues have been
posted to the following site: http://yu-budizam.com/knjige/#kulture. In this
text we will present relevant texts dedicated to philosophy and topics
related to philosophy, like meditation, mysticism, ethics, or psychology.
An overview of former Yugoslav philosophical journals in Serbian libraries: A retrospective
Authors: Albahari Biljana
Published: September 2013

The paper represents a review of philosophical magazines and other social
science magazines. It also gives a review of other cultural magazines in
which philosophical texts have been published. The review covers magazines
published in Serbia and other former Yugoslav republics starting from 1898 -
when the first philosophical magazine, Archive of Philosophy, Pedagogy and
Social Sciences made its appearance - until today. Currently, old editions of
these magazines have been converted into electronic form and, along with the
new editions, are available on the Internet. The magazines that are analyzed
in this paper were published in Serbo-Croatian, Croatian, Serbian, and
Albanian, and some are even multilingual. The magazines were distributed in
the libraries throughout the historically changing country (with its various
names) of Kingdom of Yugoslavia, Socialist Federal Republic of Yugoslavia and
Republic of Serbia.
On the concept of habitus: Feminist critic of Pierre Bourdieu’s social theory
Authors: Petrovic Dejan
Published: September 2013

Key contemporary sociological theorists, such as Foucault or Habermas rarely
explicitly discussed gender in their studies. This fact has not caused a lack
of interest in the critical examination of the theoretical systems of these
authors within a feminist perspective. During the 1990?s feminists? attention
was drawn to Pierre Bourdieu?s social theory. French sociologist?s study
Masculine Domination deals with issues of gender dynamics and its
reproduction. In this study the persistence of the asymmetric distribution of
social power between women and men is explained by concepts of habitus and
symbolic violence. As this article will show, social change cannot be
explained by Bourdieu?s concept of habitus, as a key link between social
structure and action, due to its reduction of actors to socialized bodies,
which are practically deprived of any true action potential. On the other
hand, with regard to social activism as a permanent feature of feminist
theory, this paper seeks to examine whether critical examination of
Bourdieu?s conceptual apparatus achieves to provide the means to overcome the
aforementioned shortcomings of the theoretical system of French sociologist.
In other words, this article seeks to answer the question whether such a
modification of habitus is possible, which will allow for actors whose action
is truly structured and structuring, and lead to possible change of existing
power relations.
Neoliberal Universities and the Education of Arts, Humanities and Social Sciences in Bangladesh
Authors: Anwaruddin Sardar M.
Published: September 2013

In this article, the author explores the neoliberal impacts on higher education in Bangladesh, how market-driven policies might limit the education of arts, humanities and social sciences, and whether or not this phenomenon may have consequences for the future of democracy in the country. First, the author focuses on the privatisation of higher education in the 1990s and the World Bank's influences on education policies, with specific reference to a recent policy reform initiative. Second, he takes a comparative look at the types of degree programmes offered by both public and private universities in Bangladesh. Finally, he situates his discussion in Martha Nussbaum's arguments to initiate a debate about whether or not the neoliberal universities' negligence in the education of arts, humanities and social sciences has implications for a strong and sustainable democracy.
Autonomy and Governance in Local Authority Provision for Children and Young People
Authors: Boyask Ruth , Donkin Arnet , Waite Sue , Lawson Hazel
Published: September 2013

The role of local government in addressing issues of social equity is undergoing significant reconstruction in current educational policy reforms in England. The current conceptualisation of social provision places individual rights at the centre of policy, and social responsibility is represented as the work of individuals. Drawing upon a partnership project in Plymouth, England, and the analytical lens of refraction, the authors suggest that the ‘autonomy’ of local authority workers is embedded within systems of governance, including both traditional forms of centralised control, albeit obscured, and the new modality of networked governance.