bluuebunny/crossref_metadata_2025 huggingface dataset:
New Real-Time Casing Running Advisory System Reduces NPT
Authors: Mason Colin J. , Igland Jan Kåre , Streeter Edward J. , Andresen Per-Arild
Published: September 2013

Casing, liner and completion running operations are key activities during the well construction process. Failure to reach the required setting depth may have a significant impact on well economics due to additional construction costs, deferred production and lost reserves. A substantial proportion of NPT (Non-Productive Time) associated with these operations is due to stuck pipe, and over many years the industry has made a concerted effort to reduce this.

A new advanced advisory system has been developed to enhance the monitoring of running tubulars into a wellbore. This web based system integrates real-time data, analytical capability and informative displays to identify early warning indicators associated with stuck pipe, mud losses and other anomalies.

The system has been used to actively monitor more than seventy casing, liner and completion running operations in offshore wells located in the Caspian Sea, offshore Trinidad, the North Sea and the Gulf of Mexico. Early benefits that have been realised include improved responses to stuck pipe early warning indicators, closer control of trip schedules, greater collaboration between offshore and onshore communities, and better informed and more impactful decision making. The system is currently being deployed at scale to offshore drilling rigs and is expected to bring additional benefits of standardisation, embedment of good practice and know how, and enhanced organisational capability.

As the industry drills longer, deeper, and more complex wells, the installation of longer and heavier tubulars into close tolerance wellbores will be required. This means that a deeper knowledge of the underlying physics and a better understanding of the limitations of tubular running equipment are required. It is envisioned that this advisory system will prove to be a mechanism to gain deeper insights into the casing running process, generate ideas for better designs and drive enhanced operational decision making.

This paper describes the concept, system design and infrastructure requirements. Case studies from various field deployments are illustrated and conclusions from experience to date summarised.
Improving the Economics of Marginal Fields through Technology Transfer from the Defence and Renewables Industries
Authors: Watson Paul , Stiven Tim , Mekhiche Mike , Edwards Kate , Sebire Tamara , Rixon James , Morris Chris
Published: September 2013

This paper describes how Ocean Power Technologies (OPT) successfully transferred technology developed in the Renewables sector to Defence and is currently repeating this process for the Oil & Gas (O&G) market, providing solutions that could drive down project OPEX & CAPEX to help make current fields that offer low commercial returns more attractive for development.

OPT describes the core enabling technology viz a moored, floating buoy which harvests wave energy and uses a proprietary energy management system to deliver persistent power and communications over long period multi-year deployments. It will describe a versatile marine platform which enables a wide variety of new application solutions. The system is known as an APB-350.

The results of the latest deployment of the APB-350 are described, illustrating the ability to deploy remote, in-ocean sensors and communications for subsea applications, and demonstrating the rugged survivability of the device.

It will be shown that the technology can deliver to operators a cost effective, safe, reliable, persistent power and communication platform that has the potential to reduce operational costs and improve overall production performance. Specifically, where development would traditionally require high cost power delivery systems, the technology can provide an economic solution where previously the cost was prohibitive. Potential applications are discussed in collaboration with Premier Oil such as: UUV garages for in permanent infield monitoring/inspection of assetsThe control of electric trees for CO2/water field injectionEnvironmental monitoring for pre-post deploymentReal-time on site field monitoring/sensing systems for 4D reservoir analysis and pre/post deployment surveysSecurity Cordons for offshore developmentsTemporary navigational markers for surface & submerged structures

Conclusions will be drawn regarding how the transfer approach used will benefit the oil and gas industry, to improve current operations and deliver alternative, more cost effective solutions. The ability to power alternate sensor packages and high power delivery functions, will enable operators to obtain, real-time data for remote field operations; thus allowing remote real-time asset management and enabling better monitoring and control of overall performance and safety.
Real Time 24/7 Integrity Monitoring of Mooring Lines, Risers and Umbilicals on an FPSO using 360 degree Multibeam Sonar Technology
Authors: Lugsdin Angus
Published: September 2013

For new build FPSOs or to safely extend the life of ageing assets, operators require technologies that enable them to safely monitor the subsea infrastructure in real-time, to identify problems before they occur. Annual inspections by Remotely Operated Vehicle (ROV), although useful to provide close up inspection, do not provide real-time information in the event of a mooring line failure or problem with the risers.

Through the application of multibeam sonar technology, operators can now have real-time 24/7 information on the presence and position of mooring chains, risers and umbilicals. Unlike other acoustic techniques, multibeam sonar does not require additional sensors mounted to each mooring chain or riser, therefore removing the need for regular maintenance, servicing and power source replacement by ROVs.

The multibeam sonar system provides autonomous alarms in the event of mooring line or bend stiffener failure and the accurate sonar data can be used for further fatigue analysis, assisting in the planned maintenance schedule.

This unique technology was developed for BP and has been successfully deployed on an FPSO in the North Sea, where it has provided round-the-clock integrity monitoring capability. This technology was selected in 2013 for permanent deployment on a new build FPSO entering service in the North Sea with production planned for 2015.
Providing Additional Offshore Resources Using "Walk to Work" at the Captain Field
Authors: Pena Gerald , McKeown Stephen
Published: September 2013

Across many offshore assets in the North Sea and around the world, a common challenge that Operators are continually encountering is the ability to complete desired work scopes in a bed-constrained environment.

In the summer of 2012, in order to facilitate the execution of key fabric maintenance and subsea/marine integrity scopes, the Operator utilised a relatively new solution called "Walk to Work" (W2W) at the Captain Field as a means to increase the number of available man-hours offshore to complete the work.

W2W is a term used to describe the use of a gangway installed on a vessel to transfer personnel to/from the installation at the beginning and end of their shifts. Day and night shift personnel transfers from the vessel facilitates 24-hour working on the installation, thus increasing the number of available man-hours.

The key enabling elements that the Operator addressed were the selection of the W2W system & W2W vessel and the installation of the W2W landing platforms. In addition, other key activities such as regulatory approval, Independent Verification Body approval, safety reviews, and campaign maintenance planning were imperative to the success of the project.

The W2W project at Captain delivered key business results for the Operator. A new solution to the common problem of lack of beds offshore was utilised effectively. Although it may not be the solution to every project, W2W operations should be considered as a viable alternative to conventional means of adding extra resources offshore.
Cement Sheath Integrity in Fast Creeping Salts: Effect of Well Operations
Authors: Jandhyala S. , Barhate Y. R. , Anjos J. , Fonseca C. E. , Ravi K.
Published: September 2013

A number of reservoirs around the globe are in deep environments, and often it is necessary to drill and cement through salt sections to reach them, such as in offshore Brazil. These reservoirs are mainly in deep water and are commonly referred to as pre-salt zones. It can be very challenging to drill and cement the salt section. The salt zones could be a few hundred meters thick, creep at high rates, and when in contact with drilling fluid and cement slurry, their chemical properties can change. The effect of salt movement or creep is addressed in this work.

Salt formations pose a unique challenge to the structural integrity of the wellbore by applying a time varying load on the cement sheath and casing. This load is caused by the existence of deviatoric stress and temperature variations. Deviatoric stress is the difference between formation in-situ stress and the wellbore fluid’s hydrostatic stress. When a salt formation creeps during a well operation, it does so to achieve a hydrostatic state such that the deviatoric stress is zero.

The present work is a study of cement sheath integrity under downhole thermo-mechanical loading conditions using finite element analysis (FEA). The effect of salt creep on the stresses experienced by the cement sheath at various stages in the life of the well, including drilling, cementing, shut-in, completion, and production, are simulated. A material model for salt creep is validated against experimental data reported in the literature. Multiple cement systems are compared for their effectiveness in providing zonal isolation for the life of the well. The effect of structural and thermal loads due to salt creep on cement are quantified through stresses in cement.

The method discussed in this paper should help the industry select cement formulations that can withstand stresses caused by salt movement during the life of the well. Method and case studies pertaining to offshore Brazil are presented and discussed in this paper.
Achieving Hull Structural Hotwork Repairs On Board an Operational FPSO
Authors: MacLean Calum , Lewin Matthew
Published: September 2013

This paper explores the importance of forward planning for on-station hotwork repair and demonstrates how major repair work scopes, traditionally requiring completion in dry dock, can be carried out while the FPSO is producing.

Although in theory FPSOs can be taken off station, the reality is that this has huge cost implications and reservoir issues may also make it technically very difficult. Even if the FPSO has a detachable turret, dry docking is likely to result in a minimum of 8 weeks off station. While periodical dry-docking can be easily scheduled for sailing ships, FPSO operators are increasingly looking for solutions that will enable them to keep their asset on-station and in production for upwards of 20–25 years. This being the case, it is inevitable that regardless of advances in integrity management strategies, structural hot work repairs will be required on-station.

Given the inevitability of the requirement for hotwork repairs to the hull structure, it is essential that details of how the work will be conducted are fully understood and agreed by all stakeholders long before it is necessary to start hotwork activities. The relatively small numbers of FPSOs mean that operators may have limited experience of hull structural issues and standard procedures, for example, confined space entry procedure, may not adequately address the unique issues presented by working in the enclosed but large space of FPSO tanks. It will be necessary to define and agree procedures for emergency response to incidents, IP rescue, fire and muster, isolation standards, boundary hotwork management and tank cleaning.
Wave Glider - Introduction to Innovative Autonomous Remotely Piloted Ocean Data Collection Platform
Authors: Pai Sudhir
Published: September 2013

The Wave Glider is a flagship product, the world’s first marine vehicle that harnesses kinetic energy from wave action to produce locomotion in the ocean, while remaining environmentally friendly and fuel-free; Wave Gliders are completely self-sustaining using solar panels to power their payloads. The platform includes navigational and control systems, and communication to an operations center via satellite. Control with full security can be transferred to a local set-up via a master/slave system. This game changing technology provides persistent ocean presence and a reliable data acquisition platform which can support numerous applications in the oil and gas industry. The drilling industry will benefit from magnetic survey applications for better error control. Exploration & production has applications for effective SEEP surveys, turbidity monitoring and METOC (meteorology and oceanography) applications. The subsea world will benefit from a cost effective method for data harvesting (Gateway Communications). This talk is focused around case studies conducted for customers around the world to illustrate system operation (excellence in execution), data acquisition and data analysis revolving around the applications discussed above. Value is enhanced when a number of these sensors are deployed on a swarm of Wave Gliders to conduct pre-site baseline surveys for risk and insurance management.
The Mid-Atlantic Current Hindcast
Authors: Bell M. J. , O’Neill C. K. , Waters J. , Martin M. J. , Sellar A. , Cox A. T. , Spall S. A. , Stephens R. V.
Published: September 2013

Advanced numerical modelling technology enables detailed characterisation of ocean current conditions in regions of complex hydrodynamics, such as the deeper water provinces of the continental slope. Model simulation of long-term historical conditions can significantly enhance the understanding of ocean conditions in a given location, increase the value of relatively short-term in-situ measurements, and hence reduce the uncertainty in engineering design and operational planning. However, such model results must be shown to be fully ‘fit for purpose’, which has often been a challenge to the research community. The Mid-Atlantic Current Hindcast (MACH) is a cooperative initiative between the UK Met Office, Oceanweather Inc. and BMT ARGOSS, to undertake a high integrity numerical model reanalysis of layered ocean current, temperature and salinity over a twenty year period. Applications of the resultant dataset include support to deep water offshore engineering design, marine operational planning and oil spill simulation. The project utilises state of the art assimilative ocean modelling technology and very high quality wind forcing. With the engagement of oil and gas majors, the modelling system is tuned and independently extensively validated against comprehensive in-situ oceanographic measurements. The nested ocean model system includes a coarse grid of the central and South Atlantic Ocean, and a nested very fine resolution grid covering all of the principal oil and gas concession areas in West Africa. The modelling approach also facilitates nesting fine resolution grids along the eastern Atlantic coast of South America, which provides future possibilities for deep water Brazil. The paper presents details of the modelling system, its configuration and testing during an initial pilot integration.
Installation of a Pre-Assembled Unit on an FPSO & Replacement of a Platform Crane
Authors: Wright William
Published: September 2013

In 2012, the Operator completed the successful replacement of an obsolete crane on its BLP (Bridge Linked Platform) and installation of a new module on its FPSO (Floating Production, Storage and Offloading) vessel. This was a significant project which occurred during the Operator’s TAR (turnaround) and required close coordination between numerous vessels and assets in what was a busy field.

The module installed on the FPSO consisted of stores, laboratory, fabrication workshop and additional laydown area and was installed as part of a larger accommodation upgrade on the FPSO. The existing maximum POB (Personnel on Board) on the FPSO has always been heavily utilised for normal operation of the facility with little ullage available. There was significant benefit in increasing the maximum POB to enable execution of critical maintenance, maintain focus on fabric maintenance and inspection & execution of Capital projects, thus aiding in field life extension. The additional cabins and recreation space were installed within the hull at the fore end of the FPSO where there was previously a large gym and storeroom.

In order to support the increase in POB, it was necessary to design and install a new PAU (Pre-Assembled Unit) on the FPSO which consisted of a laydown area and module which enclosed a laboratory, fabrication workshop and stores. This PAU was required to provide the asset with the facilities removed when installing the new cabins.

Due to the age of the crane installed on the platform, obsolescence of spares combined with crane capacity/operational issues meant that the platform crane was identified as a Single Point Failure for BLP operations. This lead to possible business risk exposure, as such the replacement of the crane was endorsed.

The geometry and weight of the new crane meant that the use of a considerable bumper/guidance system was required for safe installation. In addition to this, replacement of the crane left the BLP with no overside lifting capabilities through the entire TAR.

Installation of a new stores module on the FPSO and replacement of the platform crane had to be completed utilising a HLV (Heavy Lift Vessel) with adequate reach due to the PAU and crane installation locations on the assets.

The project saw the successful installation of a higher capacity platform crane, installation of the new PAU on the FPSO and an increase of 20 beds in maximum POB. All operations were completed incident and injury free, during a TAR which also incorporated approximately 30,000 man hours of platform and FPSO maintenance, significant subsea workscopes, drilling operations, and a "Walk to Work" campaign.
The Benefits and Challenges of Maintaining Offshore Structures within Lift-Installed Parameters
Authors: Maclaren David
Published: September 2013

There are clear cost and schedule benefits in maintaining offshore structures within lift-installed parameters for both Jacket structures and Topside modules. The paper sets out initially the context that drives the decision making process for determination of the various available options including lift-installed, launched and float-over.

The benefits in maximising the available lift capacity of heavy lift vessels (HLVs) include; avoiding the need to develop solutions such as barge-launch jackets that result in significantly longer fabrication schedule and costly mechanical systems, as well as the extra weight and associated costs for buoyancy tanks and launch rails. There is thus a significant benefit in maintaining weight and centre-of-gravity within the liftable envelope of the HLV.

This paper describes a case-history of Valemon jacket, installed in July 2012, which at 9200t has a lift weight close to the lifting limit of the Thialf, the world’s largest offshore crane vessel. This was achieved via the implementation of several weight saving measures during post-FEED and detail engineering stages ensuring the weight kept within the target throughout. These measures included the use of high strength steels, a fully-coated jacket, detailed and repeated analyses, the use of more sophisticated methods for ship impact, using structural details such as cones to minimise brace diameters, the use of vortex shedding restraints, minimising pile offsets relative to leg, post-installing caissons and flooding braces to reduce wall thickness.

The result was that the weight was maintained within the limit of 9500t set at the outset, with the design independently checked by the clients’ third party verifier. The application of the measures listed herein may assist in maintaining future jackets in water depths of up to 135m, as at Valemon, within the lifting envelope, with clear associated cost and schedule benefits.
An Assessment of the Impact of Water Injection System Uptime on Well and Reservoir Management on two Northsea FPSOs
Authors: Adeola Olawale
Published: September 2013

A review of two separate FPSO (Floating, Producing, Storage and Offloading) vessels water injection systems was carried out with emphasis on the impact of the uptime of the system on overall production from the fields. The focus remained on the critical aspects of the WI injection system and what constitute a top quartile performing system. Results highlights the correlation between the injection water volumes/frequency on the reservoir pressures, voidage and production in both fields with marked adverse impact as defects on key units of the water injection systems increased. On FPSO1, a poor overall uptime of the WI system over a 6 year period showed a significant reduction in the life of the fields. For FPSO2, a contrasting illustration in results showed that an improved water injection uptime arrested a decline with improved reservoir pressures and production with the desired overall impact of increasing the overall recovery and extension of the life of the fields. Ongoing improvement studies shows that an increase in the water injection system uptime up to an average of around 80% will potentially improve production by close to 3 mln bbls of oil, securing an additional 6–7 mln bbls over the life of one of the fields under review as it extends production for another 5 years.
Unlocking Small Gas Field Development In The Southern North Sea With The Application Of Modern Seismic Imaging Technologies
Authors: Darnet Mathieu , Van Loevezijn Peter , Hollman Frans , Wervelman Rob , Bruehl Matthias , Pi Alperin Juan , Shipp Richard
Published: September 2013

The economics of small gas field developments in the Southern North Sea away from any existing infrastructure is particularly sensitive to subsurface uncertainties. Applying latest geophysical approaches is a key aspect of obtaining sufficient grip on these parameters and ensuring robust project economics. For the Alpha field, the structural uncertainty due to poor seismic imaging was identified as critical and therefore a dedicated seismic imaging project was undertaken. It involved re-processing the existing seismic data with the latest velocity modeling and imaging technologies, such as Reverse Time Migration. It led to a clear improvement of the seismic character at objective level as well as a more consistent depth image. As a consequence, the expected volume of gas in place increased by 50% and additional reservoir targets were identified, considerably improving the project economics. In addition, a High Definition 3D seismic image of the shallow subsurface was for the first time successfully created over the area to assess any potential geohazards and ensured that the proposed and selected development concept had mitigations against these hazards and their consequences.
Integrated Play-Based Exploration Methodology for Screening and Prospect Assessment Using 3D Seismic Data from Makassar Strait, Indonesia
Authors: Roy Ananda Shankar , Roy Sonali , Sari Pebrina Puspa
Published: September 2013

Exploration challenges are increasing every day since easy-to-access hydrocarbon resources have been mostly exploited in past decades and the search for profitable deep-water plays is increasing worldwide. The approach is not only to look for hydrocarbons in new areas, but also to look for hydrocarbons in old places with new ideas, whilst managing exploration risk. An integrated petroleum systems based software suite allows identification and characterization of prospective areas. This approach facilitates a systematic and consistent progression from play-based exploration, to assessment of geological chance-of-success and probabilistic volumetric calculations for each prospect in a play.

A new integrated petroleum system based play evaluation workflow has been implemented to screen the Makassar Strait based on available public domain data and literature. The prospective areas were studied in detail by incorporating 3D seismic data to gain a better understanding of structural controls and lithological variations on prospectivity.

Regional interpretation maps of widely spaced 2D seismic lines from reports were used, in conjunction with different published literature for the basin, to understand the regional geological concepts and build a play fairway model. A facies dependent reservoir porosity map was prepared based on a porosity-depth relationship for the different lithologies and later improved with facies derived from the 3D seismic data. By evaluating the key elements of petroleum system possible accumulation areas were identified within the basin. Depending on the geological scenario, different geological parameters were transformed applying simple and complex transformations using a Play Chance Mapping tool to generate combined Geological chance of success (COS) maps and Economical COS of each prospect along with their associated uncertainties, through integrated prospect assessments. This Integrated Methodology minimizes the cost of exploration, especially related to drilling and management of uncertainties. It serves as guide in acquiring the right acreage for right price at right time.
Using Technology as a Lever to Reduce Seismic and Environmental Interference
Authors: Allinson C. R. , Jardine W. A.
Published: September 2013

The scale of current marine stakeholder activity in the North Sea is such that considerable effort is required to minimise the impact of operations conducted adjacent to one another. Impacts are typically spatial – vessels wanting to work in the same physical space at the same time, or acoustic – geophysical sources from separate seismic operations interfering with one another.

Site surveys are one example where significant planning is required to minimise such simultaneous operations (SIMOPS). BP had two different approaches to reduce the impact of SIMOPS at two site survey locations during 2012.

A large site survey in the Clair field (West of Shetland) required the acquisition of High Resolution (HR) seismic data within 8km of an Ocean Bottom Cable (OBC) seismic survey. At this range, acoustic interference between the two geophysical systems is significant. Avoiding acoustic SIMOPS altogether was impossible as weather constraints dictated both surveys were shot during summer months. A redesigned data processing flow was devised to reduce or eliminate seismic interference, enabling acceptable data in both surveys during significant periods of simultaneous acquisition.

A site survey at a southern North Sea platform highlighted a different SIMOPS issue – potential physical interaction with fishing equipment, during the height of the lobster and shellfish season. The survey required acquisition of bathymetry and side scan sonar data to identify seabed features. By using a tetherless, low logistics Gavia AUV solution, the overall survey footprint and fouling risk was minimised as no towed equipment was required. The survey area required for the vessel was approximately a quarter of the size of a conventional towed sensor survey, greatly reducing the impact to the fishing community.

In addition, excellent data quality was achieved.
On Leakage and Seepage from Geologic Carbon Sequestration Sites: Unsaturated Zone Attenuation
Authors: Oldenburg Curtis M. , Unger André J. A.
Published: September 2013

Geologic carbon sequestration is the direct injection of CO2 into deep geologic formations for permanent disposal. Although numerous trapping mechanisms exist in the subsurface, it is possible that CO2 will leak from the primary sequestration target and seep out of the ground. The unsaturated zone has the potential to attenuate leaking CO2 and decrease seepage and near‐surface CO2 concentrations. Attenuation processes include permeability trapping, ponding as dense CO2 spreads out on the water table, solubility trapping by infiltrating or residual water, and dilution through mixing with ambient soil gas. Numerical simulations of CO2 flowing upward through a thick model unsaturated zone were performed to investigate the sensitivity of various unsaturated zone properties on CO2 seepage flux and near‐surface CO2 gas concentrations. These two quantities are considered drivers for health and environmental risk due to exposure to CO2 For the conceptual model considered, seepage flux and near‐surface CO2 gas concentrations are most strongly controlled by the leakage rate at the water table, followed by the source zone radius. Permeability and permeability anisotropy, as well as porosity and infiltration rate are also important, although to a lesser degree. Barometric pumping causes local maxima in seepage flux and near‐surface CO2 concentrations, but has negligible effect in a time‐averaged sense. When the leakage source is turned off, the CO2 plume attentuates through dissolution into infiltrating water. For the case of a constant leakage rate, the unsaturated zone can attenuate low leakage fluxes but should not be expected to attenuate large CO2 leakage fluxes.
Discrimination of Flow Regions on the Basis of Stained Infiltration Patterns in Soil Profiles
Authors: Kulli Beatrice , Stamm Christian , Papritz Andreas , Flühler Hannes
Published: September 2013

Dye tracer experiments have often been used to study the prevailing flow regime, such as in investigating the role and extent of preferential flow of water. Flow patterns in two‐dimensional profiles provide qualitative information on the infiltration regime but are difficult to analyze and compare quantitatively. The scope of this study was to develop a quantitative method to analyze the spatial distribution of the stained areas in vertical profiles, to identify differing transport mechanisms on the basis of the pattern information, and to analyze how the discriminated patterns correspond with soil properties and structure. Dye tracer infiltration experiments were performed on 25 plots at eight sites. The spatial distribution of the stained areas in vertical profiles was analyzed and compared using digital image processing. We first split the flow patterns into similarly stained horizontal layers based on the width distribution of stained areas. All of these layers identified in the flow patterns of all 25 plots were then partitioned into groups of layers with similar patterns by hierarchical clustering. The sequence of layers found in the pattern was finally interpreted with respect to transport mechanisms and qualitatively compared with the sequence of morphological layers observed in the soil profiles. The obtained classification reliably distinguished between zones of homogeneous infiltration and zones of preferential flow, but also between zones of narrow stained structures and zones of lateral spreading (e.g., sand or gravel lenses). Dye coverage and mean width of stained structures were the most indicative factors for the different clusters. We often found an agreement between the sequences of layers found in the flow patterns and the soil horizons. However, in all profiles we observed layers in the flow patterns that did not correspond to textural and structural layers observed in the filed. It seems that knowing the pedological horizons is important but not sufficient to understand the observed flow patterns. Since the flow pattern in a given layer always depends on the overlying soil layers, similarly textured soil layers do not necessarily exhibit equal patterns. However, soil layers with a given textural sequence (e.g., fine‐course‐fine) are reflected by typical flow patterns.
Modeling the Influence of Water Content on Soil Vapor Extraction
Authors: Yoon Hongkyu , Valocchi Albert J. , Werth Charles J.
Published: September 2013

We present a comprehensive model and simulation results to assess the impact of changing water content on nonaqueous phase liquid (NAPL) mass transfer, vapor phase retardation, and slow desorption during soil vapor extraction (SVE). Contaminant mass transfer and water and energy transport processes for a one‐dimensional, nonisothermal, and single contaminant component system are considered. Literature‐derived relationships are used to express the fraction of soil surface area exposed to the vapor phase and the NAPL–gas mass transfer rate expression as a function of water saturation. Simulations are presented for two scenarios: (i) low water saturation, where soil drying is expected and direct vapor sorption to soil may be important, and (ii) high water saturation, where NAPL mass transfer to the gas phase is rate‐limited and the gas flow rate is very low. At low water saturation slow desorption controls long tailing in the effluent concentration and the cleanup time. Also, when dry air is purged through the system, water evaporation occurs, the temperature decreases, and hence, desorption rates decrease. The NAPL mass transfer rates were negligibly affected by water evaporation because time scales of the NAPL volatilization were much smaller than time scales of the water evaporation. At high water saturation, NAPL is trapped by water and NAPL mass transfer to the gas phase is limited by diffusion through water films. For this case, NAPL mass transfer is slow and thus controls concentration tailing and cleanup times.
Sorption of Pesticides Atrazine, Isoproturon, and Metamitron in the Vadose Zone
Authors: Coquet Yves
Published: September 2013

Knowledge of the sorption properties of the vadose zone is essential to provide sound risk assessments of groundwater contamination by pesticides. This study explored the sorption properties of the vadose zone of a 187‐ha agricultural catchment located 120 km northeast of Paris, France. Eocene geologic materials composing the vadose zone include limestones, marlstones, clays, and sands. Distribution coefficients (Kd) of 14C‐labeled atrazine (6‐chloro‐N2‐ethyl‐N4‐isopropyl‐1,3,5‐triazine‐2,4‐diamine), isoproturon [3‐(4‐isopropylphenyl)‐1,1‐dimethylurea], and metamitron [4‐amino‐4,5‐dihydro‐3‐methyl‐6‐phenyl‐1,2,4‐triazin‐5‐one] were measured in batch on 30 vadose zone samples, and their sorption isotherms measured on six representative samples. Kd values for each pesticide were highly variable and ranged from 0.10 to 2.99 L kg−1 for atrazine, 0.06 to 1.27 L kg−1 for isoproturon, and 0.06 to 2.08 L kg−1 for metamitron. Two vadose zone materials, a lignitic clay and a clay with low organic C content, were found to have Kd values higher than those of the topsoil. Most of the sorption isotherms in the vadose zone were found to be linear. Kds could be well predicted by the clay content (particle‐size fraction < 2 μm after organic matter and carbonates removal) of the vadose zone. This result suggests that simple but efficient pedotransfer functions may be derived to predict the sorption properties of the vadose zone at the catchment scale.
Measuring Spectral Dielectric Properties Using Gated Time Domain Transmission Measurements
Authors: Harlow R. Chawn , Burke Eleanor J. , Ferré Ty P. A. , Bennett John C. , Shuttleworth W. James
Published: September 2013

A method to measure the frequency‐dependent dielectric permittivity of simple materials based on a time domain transmission technique is described. A vector network analyzer (VNA) was connected to a twin‐rod transmission line via a coaxial cable. The complex dielectric permittivity was found from the difference in phase and magnitude between a reference line surrounded by air and the same line surrounded by the substance of interest. The spectral response showed periodic variations in the dielectric permittivity as a result of multiple reflections in the experimental setup. These multiple reflections can be removed by using a time domain gate that selects only the primary transmission and filters out any subsequent reflections. It is essential that the apparatus be designed so that the first reflection is well separated from the primary transmission. This requires a long transmission line and a long coaxial cable. However, if the transmission line is too long, excessive conductive or dielectric losses make it hard to detect the primary transmission. The application of the gated time domain transmission technique to measure the frequency‐dependent dielectric permittivity of water, ethanol, sand and saturated sand is demonstrated. This method does not have the typical limitations on sample volume. In addition, it does not require the assumptions necessary in previous time domain spectroscopy methods applied to open transmission lines where a probe model is used in conjunction with simple Debye relaxation and/or inverse methods.
Measuring Water Content in Saline Sands Using Impulse Time Domain Transmission Techniques
Authors: Harlow R. Chawn , Burke Eleanor J. , Ferré Ty P. A.
Published: September 2013

This paper discusses two time domain transmission (TDT) electromagnetic methods for measuring soil water content in a sand and examines the impact of pore water salinity on the resulting measurements. The first technique calculates the time taken by an impulse traveling one way through the medium relative to its time taken in air. The second method converts this impulse to the frequency domain via a Fast Fourier Transform (FFT) and calculates the travel time from the difference in phase measured in air and that measured in the medium at each frequency, resulting in a measurement of the frequency‐dependent travel time. The relationship between travel time and water content was determined for pore water electrical conductivities (EC) ranging from 0.5 to 40 dS m−1 At 0.5 dS m−1 the relationship was similar to that found by previous researchers using time domain reflectometry (TDR) measurements. At pore water EC ≥5 dS m−1 the travel time was faster than that found for 0.5 dS m−1 at the same water content, contradicting traditional thinking based on transmission line theory and differing from results of TDR methods. In addition, for pore water EC ≥5 dS m−1, the relationship determined between travel time and water content was shown to be independent of pore water EC, to the precision of the TDT measurement technique. As a result, the impulse TDT method and this calibration relationship may improve our ability to measure soil water content under natural field conditions and may encourage further investigation of the impact of salinity on the spectral dielectric response of porous media.
Joint Pain Undergoes a Transition in Accordance with Signal Changes of Bones Detected by MRI in Hip Osteoarthritis
Authors: Kamimura Mikio , Nakamura Yukio , Ikegami Shota , Uchiyama Shigeharu , Kato Hiroyuki
Published: September 2013

Objectives:

In this study, we aimed to investigate whether joint pain is derived from cartilage or bone alterations.

Methods:

We reviewed 23 hip joints of 21 patients with primary hip osteoarthritis (OA), which were classified into Kellgren–Laurence (KL) grading I to IV. Plain radiographs and magnetic resonance imaging (MRI) were obtained from all of the 23 joints. Two of the 21 patients had bilateral hip OA. Pain was assessed based on the pain scale of Denis. A Welch t test was performed for age, height, weight, body mass index, bone mineral density, and a Mann–Whitney U test was performed for KL grading.

Results:

Four of 8 hip joints with pain and OA showed broad signal changes detected by MRI. Fourteen hip joints without pain, but with OA did not show broad signal changes by MRI. Collectively, MRI analyses showed that broad signal changes in OA cases without joint pain or with a slight degree of joint pain were not observed, while broad signal changes were observed in OA cases with deteriorated joint pain.

Conclusion:

Our findings suggest that hip joint pain might be associated with bone signal alterations in the hips of OA patients.
Representation of philosophical problems in Nis review Gradina: Periods 1900-1901 and 1966-1980
Authors: Nikolic Ivan
Published: September 2013

In this paper, which will be conceived in two units, we try to depict the
form and content of those texts which could be marked as philosophical in
intention. As we will see, that intention, in the first period of publishing
(1900-1901), was determined by a strong influence of German and French
Enlightenment. This influence was only natural, given the need for education
for the newly-liberated population of Nis. The second period (1966-1980) can
be discribed as having a more partial interpretation of philosophical
problems. At the end of the account, the article is focused on the
investigation of cultural and social reasons which caused such a tendency. In
this sense, the founding and development of the Faculty of Philosophy in Nis
was the main reason behind the progress in philosophical publishing.
Perfect and imperfect states
Authors: Nikitovic Aleksandar
Published: September 2013

Early Greek ethics embodied in Cretan and Spartan mores, served as a model
for Plato`s political theory. Plato theorized the contents of early Greek
ethics, aspiring to justify and revitalize the fundamental principles of a
traditional view of the world. However, according to Plato`s new insight,
deed is further from the truth than a thought i.e. theory. The dorian model
had to renounce its position to the perfect prototype of a righteous state,
which is a result of the inner logic of philosophical theorizing in early
Greek ethics. Prototype and model of philosophical reflection, in comparison
to philosophical theory, becomes minor and deficient. Philosophical
theorizing of early Greek ethics philosophically formatted Greek heritage,
initiating substantial changes to the content of traditional ethics.
Replacement of the myth with ontology, as a new foundation of politics,
transformed early Greek ethics in various relevant ways.
Ideal and nonideal theory: A conceptual overview
Authors: Trifunovic Milica
Published: September 2013

The article gives conceptual clarification on a distinction between ideal and
nonideal theory by analyzing John Rawls? theory as presented in his books ?A
Theory of Justice? and ?The Law of Peoples.? The article tries to show the
importance of ideal theory, while at the same time pointing out that the
distinction, ideal and nonideal, needs further qualification. Further, the
article also introduces the distinction of normative and descriptive into
ideal and consequently nonideal theory. Through this four-fold distinction it
is easier to establish the function of each theory and the separation of
work-fields between philosophers, politicians and lawyers.
Social construction of “other” as “primitive”
Authors: Bozilovic Nikola
Published: September 2013

The author of this paper deals with the problem of cultural difference
through the analysis of the relationship ?us? - ?others?. He searches for the
answer to the question why the culture of other peoples or individuals are
often considered inferior in many societies. This type of treatment leads to
the extreme where the position of the ?other? is reduced to the level of
?primitive? (less valuable, lowly, and brutal). In such a context, the author
analyzes theoretical concepts of the Enlightenment rationalism of the 18th
century and the anthropological evolutionism of the 19th century, believing
that the roots of the negative assessment of the ?other? can be found in
them. Namely, the majority of these theories conduct a hierarchization of
culture according to the time and value principles, from which peoples and
cultures can be classified as ?primitive? and ?civilized?. European modernism
provided the vision of history as one of linear growth, which led to modern
cultures being a priori declared more valuable and culturally more sublime.
However, modern cultures are also classified among themselves according to
value principles. The differentiation of cultures is performed using various
stereotypes, and the idea of progress as rational improvement in the sphere
of material culture, science, and technology legitimizes the transformation
of the different (other) into primitive. From this prejudice, according to
the author, emerges the Eurocentric thought on the exclusiveness of the
European culture, which latently justifies colonialism and other negative
phenomena coming from the European civilization. Primitivism is being
presented as an objective state, while it is, in fact, the case of a social
construction which has the aim of proclaiming the ?other? as ?primitive?.
Model for research of the style of political leadership in Serbia at the crossing of the millennium
Authors: Pavlicevic Predrag
Published: September 2013

This article indicated a model for a scientific description of styles of
political leadership in Serbia from 1990 to the present, more precisely,
pointed the basic elements of concept developed by the author in the study
?The style of political leaders in Serbia in the period 1990-2006? (2010).
For the evaluation the author uses analytical tools that include the
aforementioned concept, simultaneously indicating correlative theoretical
approaches the aforementioned study did not examine, and may be of importance
for the research of political elites in Serbia. This contributes the
epistemological part of the method, which is registered in the definition of
the style of political leadership as a term and the category apparatus that
follows - understood from the aspect of the political style: the style in
building political power, the style of political communication, the style of
building one?s legitimacy, the ideological style, the styles of political
language, symbolism and rituals, non-verbal communication and style in
expressing patriotism. Starting from the fact that political styles are
related to characteristics of political cultures and that it is necessary to
make a concept of ideal typical models of styles focused on political
subjects, this article marked the styles of political leadership typology
related to the specific acting of political leaders in Serbia: authoritarian,
republican, realistic, populist, conformist, revolutionary and style of a
politician-rebel.
Euthanasia: The conceptualization of the problem and important distinctions
Authors: Djeric Milijana
Published: September 2013

The aim of this work is twofold. On the one hand, the intention is to provide
analysis of the issue of euthanasia. On the other hand, this approach
necessarily leads to a discussion toward the provision of an adequate
definition of euthanasia. Therefore the article, first of all, refers to the
multi?layered aspect of the term euthanasia. To avoid ambiguity and other
uncer?tainties while providing the definition of euthanasia, the authors
carefully perform a conceptual analysis. This leads to the establishment of a
clear distinction between actions which, due to their motives or their method
of execution, cast a shadow on the meaning of this medical procedure.
How not to argue about immigration
Authors: Corlett Angelo , Unger Kimberly
Published: September 2013

This paper describes and assesses the arguments offered both against closed
borders and in favor of a more open borders approach to U.S. immigration
reform as those arguments are set forth in R. Pevnick?s book, Immigration and
the Constraints of Justice. We find numerous problems with Pevnick?s
reasoning on both counts.