bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of The Potential of Microbial Restoration of Natural Gas Deposit with CO2 Sequestration by Investigating Indigenous Bacteria in a High CO2 Content Oilfield
Authors: Mori Ryo , Sugai Yuichi , Sasaki Kyuro , Fujiwara Kazuhiro
Published: January 2012

We are focusing on in-situ microbial conversion of CO2 that was injected into depleted oil reservoirs for CCS into CH4 by oil-degrading and H2-producing bacteria and hydrogenotrophic methanogens. Those bacteria are concerned to be affected under high CO2 condition, which causes pH reduction of the brine; therefore, we estimated the possibility of this microbial conversion process under high partial pressure of CO2 in this study by investigating the following: –The habitations of above bacteria in a high/low CO2 content reservoir–The pH reduction of brine under high partial pressure of CO2–Productivities of H2 and CH4 by indigenous bacteria of the high CO2 content reservoirs

Thermotoga sp. and Thermoanaerobacter sp. whose productivities of hydrogen from crude oil had been shown by Fujiwara et al.1) were detected as a dominant in the high CO2 content reservoir. Moreover, Methanobacterium sp. and Methanothermobacter sp. that are well known as hydrogenotrophic methanogens were also detected from the reservoir. These results indicate that the effective microorganisms for this microbial conversion process can inhabit reservoirs that stored with CO2 for CCS dominantly.

The pH of the brine including bicarbonate more than 0.1 mol/L can be maintained at 7.0 to 8.0, which was suitable pH for many kinds of microorganisms, even under high CO2 partial pressure such as 5.0 MPa, suggesting that this microbial conversion process can be applied easily on reservoirs whose brine is abundant in bicarbonate.

Enrichment culture experiments of the brine were carried out under high CO2 partial pressure (3.0 MPa) at 75ºC. Both H2 and CH4 production were found in not only the brine having the pH buffering action but also the brine whose pH was reduced significantly under high CO2 partial pressure; therefore, the microbial conversion process may be also expected in normal reservoirs that have poor acid neutralizing capacity.
Methodologies and Tools for Coalbed Methane (CBM) Field Development Planning Studies
Authors: Ryba Artur , Everts A. , Alessio L.
Published: January 2012

Resource plays such as Coalbed Methane (also called Coal Seam Gas) fields typically exhibit a number of unique characteristics that set them apart to other hydrocarbon accumulations. We will argue in this paper that as consequence, conducting effective field development planning studies for CBM resources requires adopting a markedly different approach to the ones typically followed with conventional oil and gas fields.

In contrast to traditional offshore plays, replete with a rich literature of best practices and adequate tools, coalbed methane field development planning typically involves very large areas and number of wells, hence a correlative abundance of (static and dynamic) data, but also displays an often surprising variability between neighbouring wells. This variability is the consequence of a high degree of heterogeneity present at a small (1’s-10’s metres) to medium (10’s-100’s meters) scale, notably for permeability, but also isothermal properties, gas content, and even net coal distribution and seam geometry for some plays.

This paper offers insights on integrated development planning methods, uncertainty management techniques and modelling workflows, accumulated through the experience of a number of CBM plays. Expected relationships and possible cross-parameter models for the key reservoir properties are discussed. The development of practical tools to characterise the reservoir properties, as well as the performance of different well and completion configurations, simulation, field development planning, all the way to ultimately assessing the economic potential of the play are also illustrated.
Identification of Seismic Geomorphic Features with Hydrocarbon Indicators in the Deepwater Andaman Basin, India
Authors: Nandi A. K. , Samanta B. G.
Published: January 2012

High quality 3D seismic data has facilitated the use of seismic geomorphology in identifying features of hydrocarbon indication in the deep waters of Andaman Basin to the east of Andaman islands. In Andaman basin, presence of various seismic geomorphic features like turbidity-flow leveed channels, channel overbank sediment waves, crevasse splay/ overbank splay deposits, frontal splays or fan lobes, debris flow deposits etc. have been reported (Nandi et. al., 2009). Additionally, these areas show presence of direct hydrocarbon indicators (DHI) within the Neogene sediments and that makes the hydrocarbon exploration in the area quite interesting. The 3D seismic data with its seismic time slices, horizon slices and interval attributes provides images of deepwater depositional systems in a map view that can be analyzed in the light of classical geomorphological concepts (Posamentier and Kolla, 2003).

An attempt has been made to study all features depicting hydrocarbon indications by applying the concept of seismic geomorphology. These are gas chimneys, gas clouds, BSR, flat spots, seismically obscured areas, charged channels and pockmarks. In the study area, the charged channels with gas chimney like features are common in the back-arc part of the basin whereas such channels are less in the fore-arc part of the basin. This may be attributed to the frequent tectonic disturbances in the back-arc part and its nearness to the spreading center in between Alcock and Sewell rises. All these features of hydrocarbon indications give rise to the expectation of a breakthrough in the form of an major discovery of hydrocarbons in the deepwater areas of Andaman.
Improving Oil Recovery and Injection Strategy in Shallow Reservoir (Rindu Reservoir) of Area 3&4 Duri Steam Flood
Authors: Lumbantobing Sudianto , Natalia Sandra , Silalahi Henri Sahat
Published: January 2012

The Rindu reservoir of Area 3&4 Duri Field has been developed economically since 1994. Since it is shallow reservoir and penetrated by existing PK producer wells, the Rindu reservoir is started producing commingles with PK sand in 1997 (Rindu Vertical Expansion/ RVE well). In alignment to this effort, the Rindu injection also started at the same year. After 8 years production-injection, these commingle producers have poor production performance due to back pressure, cross-flow, and scaling.

Through heat management review, it was found that Rindu in the southern Area 3&4 has longer maturity response, poorer injection (200 BSPD), and longer heating time (~80 years).

An integrated geological and reservoir engineering study of Rindu performance is carry out to define improvement production and steam injection in southern part Area 3,4. The study resulting some key finding:

Rindu and PK have significant reservoir pressure and temperature different. All poor performance RVE producers are facing cross flow/backpressure and scaling problem Low drainages point in Rindu pattern resulting high reservoir pressure Low injection performance controlled by high backpressure Southern Area 4 Rindu sand has a poorer reservoir quality compare to Northern part.

The project team proposed to drill separate Rindu only to avoid cross-flow, back pressure, or scaling issues. At the same time it improved Rindu pattern drainage points. The project also proposed to increase steam injection rate gradually after reservoir pressure decreased. After completing the project, the Rindu reservoir deliver 50 BOPD/well, increase steam injection by 500% (1000 BSPD), accelerate pattern heating process (~2.5 years), and better reservoir management.

This study recommends developing Rindu and PK reservoir separately. Injectivity improvement will be resolved through completing pattern drainage points and deliver better reservoir heat management.
Reservoir Risk Assessment in Turbiditic Slope Channels: A Case Study from the Kutei Basin (Offshore Kalimantan, Indonesia)
Authors: Caselgrandi E. , Cavanna G. , Corti E. , Della Rossa E. L. , Rovellini M. E. , Suhardiman Y. , Cerutti A. , Sugama C.
Published: January 2012

The studied reservoir consists of turbiditic slope channels which form elongated sandy bodies with dimension of 4 to 12 Km in length and 1 to 4 Km in width. The thickness is varying from few metres to almost one hundred. These channels are hydraulically separated and characterized by high values of porosity and permeability.

These sand bodies were identified and porosity characterized by means of seismic data. The first three wells have proved the correlation between gas-bearing sands and "low-impedance" seismic responses. Nevertheless, since those wells did not cross all the sand bodies (only 6 out of 14) the main problem at that stage was the risk assessment of the hydrocarbon occurrence in the remaining bodies.

In order to assess this risk the first approach was to identify, for all the bodies, relevant seismic criteria (Amplitude strength, Signal noisiness, Fragmentation and Recon AVO) to use for a qualitative evaluation defining a ranking of the undrilled bodies. The following step was to apply a Bayesian approach to assess the relevant probability of hydrocarbon occurrence. This technique requires the estimation of two parameters: prior probability based on geological area knowledge and likelihood derived from seismic indicators.

On the base of the probability ranking a limited number of scenarios was defined. For each scenario a dedicated plan of development was assigned. A new appraisal well was drilled after this evaluation. This allowed verifying the validity of the ranking system used to estimate probability of success with regards to the undrilled segments. The results show good agreement between seismic data and well’s results with one (positive) exception.

Moreover a traditional "Risk Analysis" was performed in perforated bodies to sample all the critical parameters (static and dynamic) and to build several models. By these models a set of volumetrics and production profiles were obtained.
Quantification of Drillstring Integrity Failure Risk Using Real-Time Vibration Measurements
Authors: Arevalo Yezid , Fernandes Ashley
Published: January 2012

Vibration measurements have traditionally targeted the improvement of downhole tool reliability. This paper targets the effects of vibration on the complete drillstring. Failures associated with drillstring vibration continue to happen in spite of the sophistication of today’s measurements. These failures represent a very significant amount of lost time which we target to improve.

The industry has a limited knowledge database or tools for managing and quantifying the risk of vibration to the complete drillstring. Operators are faced with an unknown quantification of the risk severity when attempting to mitigate vibration. By quantifying the risk, this work demonstrates how the prevention of incidents can be achieved. These incidents include, but are not limited to, twistoffs, backoffs, and bottomhole assembly (BHA) component failures.

The proposed solution is based on real-time measurements of drillstring vibration to estimate an ongoing drillstring integrity risk which is used as a guideline to improve decisions while drilling the well. This solution has been developed using advanced vibration sensors to discriminate between different types of vibration. This was critical to estimating realistic cumulative damage to the drillstring, which is highly dependent on the type of vibration suffered by the assembly and the onset of vibration modes coupling.

This paper shows that approximately 80% of drillstring integrity failures analysed can be identified and prevented using the proposed risk quantification solution. This result has been obtained despite the fact that fatigue or wear of drillstring components prior to a run is unknown and vibration sensors were located at a single position in the drillstring. This indicates that the primary contributor to drillstring failures is the drilling conditions for any given run.
Slimhole Wells at the Raageshwari Deep Gas Field
Authors: Crighton Alan , Peytchev Peter , Upadhyay Abhishek , Doodraj Sunil , Malik Sumit D. , Varghese Roy , Sawyer Graham , Lochhead Ian , Meempat Balu Govind
Published: January 2012

During exploration activities in the Thar Desert of Rajasthan, India, Cairn India Ltd. discovered numerous oil fields in the Barmer Basin. The oil reservoirs are relatively shallow and benign in terms of pressure, temperature and corrosivity, but they posed significant flow assurance challenges due to relatively high crude viscosity, wax content and pour point. As a result, surface facilities are reliant on heat for flow assurance. Total reliability of power and fuel supply for the facilities was essential to ensure export product quality and for flow assurance for the waxy oil.

The paper presents Cairn’s approach of utilizing state-of-the-art technology that integrates all relevant data scenarios for the drilling and production systems for this lean gas condensate reservoir. This development will provide the necessary power and heating fuel supply and the primary gas supply for the main oil processing terminals and for power generation stations along a 600km heated export pipeline.through the end-of-life for the major oilfields discovered in Western Rajasthan, India.

Raageshwari Deep wells target tight, predominantly volcanic reservoirs with cost-effective monobore designs that include multiple fracture stimulations in various pay zones to maximize well productivity. The slimhole well design, dynamic completion design, and careful bit design and selection successfully enabled the drilling of these wells with 26% cost savings on the total budget for drilling ten wells ($ 2M per well). A program highlight was the drilling of volcanic tuff formations in a single run.

The paper will describe detail aspects of monobore well planning and well design implementation including fracture stimulations. It will also demonstrate how this significantly improved the well delivery that contributed to effective development plans for these major oilfields.
Offshore Gas Condensate Field History-Match and Predictions: Ensuring Probabilistic Forecasts Are Built With Diversity in Mind
Authors: Gross Herve , Honarkhah Mehrdad , Chen Yuguang
Published: January 2012

Ideally, probabilistic forecasts improve the decision quality, capture upsides and mitigate downsides. Unfortunately, one of the risks associated with probabilistic forecasts is the possible creation of a large number of models with similar properties or responses. Methods to identify representative models from an ensemble of models are thus necessary.

In this paper, we extend the use of distance-based methods, developed at Stanford Center for Reservoir Forecasting, and Kernel clustering techniques to the selection of models for economic decision-making. Using mathematical tools, the large set of models in a high-dimensional space is mapped to a low-dimensional space and a distance function based on several prediction-related quantities is used to quantify the similarities and dissimilarities among an ensemble of history-matched models. We then construct a small portfolio of models with a diverse range of prediction performances for less cost-intensive probabilistic forecasts.

The approach is applied to an offshore gas condensate field in the Asia-Pacific region. Two possible development plans were competing: continue to produce from existing geological structures, or extend the development to accumulations connected through a saddle in the carbonate reservoir. The decision was impacted by the uncertainty on remaining volumes in place and connectivity between structures.

Based on the uncertainty management plans, 925 history-matched models are generated with genetic algorithms. Within the context of distance-based modeling, an application-tailored distance function between models is designed, balancing static (scenario independent) and dynamic (scenario dependent) properties of the models. Then, eight diverse and representative models are selected among the 925 models. We show that the eight selected models, while offering an equally good history-match, cover well the uncertainty ranges of the static and dynamic properties considered. The selected models can be used to evaluate different possible development scenarios for final business decision making.
Selecting Location for CO2 Storage in Indonesia: Risk Assessment on a Basinal Scale
Authors: Amijaya Donatus Hendra
Published: January 2012

CO2 capture and geological storage (CSS) is one alternative that offers a new set of options for reducing greenhouse gas emissions. The concepts of CO2 storage refer to the injection of carbon dioxide in dense form into aquifers, which basically must meet several conditions. Three types of geological formations that usually can be used for the geological storage of CO2 are oil and gas reservoirs, deep saline formations and unmineable coal beds. Indonesia has about 60 Tertiary sedimentary basins, however that great precautions must be taken for selecting particular sedimentary basin for carbon dioxide storage. Preliminary risk assessment can be conducted on basinal scale based on possibility of leakage and geothermal gradient. On basinal scale, sedimentary basins in Indonesia are of intermediate to high risk for CO2 storage.
The Best Practices In Moisture Control of Sour Natural Gas as Export Gas: Case Study on Line Water Content Analyzer Assessment in a Gas Plant
Authors: Bahmannia Gholamreza
Published: January 2012

The dry sour gas is 4th gas plant’s main product for transfer and injection into Aghajari Oil Field as EOR projects. Moisture control and monitoring in sour gas is a critical parameter because of severe corrosion problems that are associated with sour gas. For assessment of Michell online process moisture analyzers, in comparison to laboratory Michell’s ceramic moisture sensor and portable monitor (ASTM D-5454) and Chilled mirror device as manual dew point tester (ASTM D-1142), a periodical test has been done. The results showed acceptable accuracy range of online analyzers and the calibration period confirmed. In this paper all recorded data has analyzed by statistical methods.
Middle East Case-Study Review of a New Free-Pipe Log for Stuck-Pipe Determination and Pipe-Recovery Techniques
Authors: Torne Juan , Rourke Marvin , Derouen Brock , Kessler Calvin
Published: January 2012

Significant drilling challenges can exist when drilling in mature fields or in reservoirs that are subject to various geomechanical stress regimes associated with overpressure, tectonic stress, and depletion. Despite mitigation efforts to reduce stuck-pipe occurrences, drilling problems leading to stuck pipe still occur. When conventional techniques used to free the drillstring are ineffective, wireline logs are often run to determine the stuck depth of the drilling assembly and to release the pipe above the free point.

The traditional free-point (FP) logs used to determine the depth of stuck pipe are based on a measurement of strain when stress is applied to the pipe between two points. These measurements are taken at specific intervals and require the tool arms to firmly grip the pipe to prevent movement that could mask the strain measurement. This simple method is difficult to implement reliably. Because it depends on the skill of the specialist operator, pipe-recovery operations include "more art than science." A new technology, based on electromagnetic measurements, can now make a continuous FP log. The log consists of two passes, with and without stress applied to the pipe. By comparing the two responses, service company specialists and drilling engineers can interpret the log without the need for highly-experienced personnel.

This paper reviews several cases from the Middle East and provides information about the tool response in various parts of the drilling assembly. It also reviews pipe-recovery techniques that are recommended depending on the FP log response and the specific drilling assemblies, such as drill collar, drill pipe, crossovers, and jars. The pipe-recovery techniques discussed include explosive back-off techniques, explosive pipe severing, and various pipe cutters. The case study examples demonstrate the improved efficiency and reliability of determining stuck-pipe intervals and subsequent successful pipe recovery.
New and Improved Methods for Performing Rate-Transient Analysis of Shale Gas Reservoirs
Authors: Nobakht M. , Clarkson C. R. , Kaviani D.
Published: January 2012

Multi-fractured horizontal wells are currently the most popular method for exploiting low-permeability tight and shale gas reservoirs. Production data analysis is the most widely used tool for analyzing these reservoirs for the purpose of reserves estimation, hydraulic fracture stimulation optimization, and development planning (Ambrose et al., 2011). However, as pointed out by Clarkson et al. (2011), a fundamental problem with the application of conventional production data analysis to ultra-low permeability reservoirs is that current methods were derived with the assumption that flow can be described with Darcy’s law. This assumption may not be valid for tight/shale gas reservoirs, as they contain a wide distribution of pore sizes, including in some cases nanopores (Loucks et al., 2009). Therefore, the mean-free path of gas molecules may be comparable to or larger than the average effective rock pore throat radius causing the gas molecules to slip along pore surfaces. This results in slippage non-Darcy flow, which is not accounted for in conventional production data analysis.

Clarkson et al. (2011) modified the pseudo-variables used for analyzing gas reservoirs in production data analysis to account for slippage. They demonstrated that if the effect of slippage is not considered, it leads to noticeable errors in reservoir characterization. Clarkson et al. (2011) also mentioned that even after using the modified pseudo-variables, the values for permeability and fracture half-length do not exactly match the input data to simulation. In this paper, a methodology to properly analyze the production data from a fractured well in tight/shale gas reservoir producing under a constant flowing pressure in the presence of desorption and slippage is presented. This method uses new pseudo-time definition instead of conventional pseudo-time currently being used in production data analysis. The method is validated using a number of numerically-simulated cases. It is found that the newly-developed analytical method results in a more reliable estimate of fracture half-length or contacted matrix surface area, if permeability is known.
A Prediction of Water Breakthrough Time in Low-Perm Gas Reservoirs with Bottom Water
Authors: Zhang Qinghui , Li XiangFang , Song Zhaojie , Yan Bicheng , Yin Bangtang , Li Qian
Published: January 2012

For low permeability reservoirs with threshold pressure gradient, the dynamic of water coning is different from that in the conventional gas reservoir. If conventional prediction methods are applied to calculate the water coning time, errors occur and cannot reflect the real situation of the water coning. This paper considers the impact of threshold pressure gradient, modifies the process of gas flow and water coning and through mathematical deduction, this paper gets water breakthrough time prediction formula in low-perm gas reservoir with bottom water. Through calculation in cases, this paper preliminarily analyzes the effect of threshold pressure gradient on water breakthrough time. With an increase of threshold pressure gradient, the water breakthrough time decreases, and the gas well see water earlier.
A Review on Offshore Concepts and Feasbility Study Considerations
Authors: Maddahi Maryam , Mortazavi Seyed Javad
Published: January 2012

There is no doubt that choosing the excellent technology and operation is one of the keys to achieve sustainable global energy. With the quick advancement in the subsea technology and offshore industry and its influence on the global oil and gas production through the past three decades, an update working knowledge of engaged offshore facilities around the world seems to be essential for a successful petroleum field development. Selection of the most appropriate equipment and process through the early exploitation study stages of developing an offshore petroleum reservoir can determine the right facilities for delivering the greatest value.

The current paper gives an overview of characteristics, and features of offshore production facilities, their advantages and disadvantages according to the most common offshore system selection and feasibility studies considerations. It has been tried to point out the most important criteria of the related Issues and concerns during a process and facilities selection for a potential case of installing the subsea completion as well as proposing processes to help in selection of the right concept. Major considerations in the process and facility selection for a petroleum field, such as shore distance, drilling and well intervention, topside weight, utilities, accessibility, regional influences, financial and HSE considerations, and particularly water depth and well count, as well as their influences on the final decision have also been explored.

The review also introduces common components of a subsea completion system such as wellheads, manifolds, flowlines and risers, connection systems, control systems and umbilicals, installation tooling, and then it makes a comparison between different types of Xmas trees as well as various well arrangements. Finally, the paper summarizes the subsea development phases for establishing the right concept.
Environmental benefits of reclaimed water: an economic assessment in the context of the Water Framework Directive
Authors: Alcon Francisco , Martin-Ortega J. , Berbel J. , de Miguel M. D.
Published: January 2012

The European Water Framework Directive (WFD) prescribes that all water bodies in Europe should achieve ‘good ecological status’ (GES). Maintaining a certain water flow is a pre-condition for the achievement of GES in areas of water scarcity. In such areas, reclaimed waste water is seen as a promising measure to keep river flow at a sufficient level. The contingent valuation method is applied here to estimate the non-market environmental benefits of using reclaimed water to maintain river flow levels in the Segura River Basin in south-eastern Spain. The assessment of the economic benefits of specific measures gives policy makers more information than a cost-effectiveness analysis alone, which is currently the most commonly used tool to assess potential measures under the WFD. The results show that the implementation of this measure produces significant non-market benefits that are larger than the investment and operational costs of reclaimed water treatment plants.
The economic value of basin protection to improve the quality and reliability of potable water supply: the case of Loja, Ecuador
Authors: Zapata Samuel D. , Benavides Holger M. , Carpio Carlos E. , Willis David B.
Published: January 2012

The objective of this study was to estimate the economic value that people living in Loja, Ecuador, place on the protection of two basins when the protection is designed to improve both the quality and reliability of the water supply for human consumption by urban residents. Empirical results indicate that households have an average willingness to pay (WTP) of $5.80 per month to preserve the basins. The main variables affecting WTP are current monthly water cost, perception about the fairness of the existing water price, the number of hours that service is available, and the gender of the individual interviewed. The results of this study, and the later implementation by the Loja City Municipality of a basin protection project funded through a fee on water users, provide evidence that households at all income levels strongly support and are willing to pay for a project that has the potential to improve the quality of water services and protect the environment.
Gaming in a benchmarking environment. A non-parametric analysis of benchmarking in the water sector
Authors: De Witte Kristof , Marques Rui Cunha
Published: January 2012

This paper discusses the use of benchmarking in general and its application to the drinking water sector in particular. It systematizes the various classifications of performance measurement, discusses some of the pitfalls of benchmark studies and provides some examples of benchmarking in the water sector. After a presentation of the institutional framework of the water sector in the Belgian region of Flanders (without any benchmarking experience), Wallonia (recently started a public benchmark) and the Netherlands (introduced a public benchmark in 1997), we point to their different stages in the benchmarking cycle. As these three regions are comparable apart from their different implementation of benchmarking, a non-parametric estimation of the productivity gains over time (by a Malmquist index) could be insightful. The ‘carrot’ and the ‘stick’ of benchmarking seem to offer an effective incentive to trigger performance. In addition, the Malmquist decompositions provide some indication on the ‘gaming’ of the stakeholders by the water utilities.
Economic valuation of a multiple use wetland water system: a case study from India
Authors: Mukherjee Sacchidananda , Kumar M. Dinesh
Published: January 2012

In the Gangetic floodplain of West Bengal, multiple use wetlands (MUW) play a significant role in the livelihoods of the local people. Over the years, these multiple use systems are being converted into single use systems for commercial gain by economically, socially and politically dominant groups. Compared to single use water systems, MUW benefit a larger number of people belonging to different socio-economic strata. Also, the economic and ecological functions of MUW change over time and space. These dynamic aspects of wetlands are often not fully recognised. Attempts to classify wetlands according to their uses across ecological zones and to carry out their economic valuation are limited. A wetland was selected in the Barddhaman district of West Bengal to evaluate the economic benefits of various direct uses. The study shows that the major economic benefits that people living in the surrounding area of the wetland derive are from wetland cultivation, direct irrigation, jute retting and fisheries. The largest benefit was from jute retting followed by fisheries and wetland cultivation. The irrigation benefits were found to be low owing to the greater distance of the farm land from the wetland, and easy access to groundwater owing to the shallow aquifers in the region.
Of transboundary basins, integrated water resources management (IWRM) and second best solutions: the case of groundwater banking in Central Asia
Authors: Karimov Akmal , Giordano Mark , Mukherji Aditi , Borisov Vecheslav , Djumanov Jamol
Published: January 2012

This paper tells the story of trade-off between hydropower and irrigation and its implications for groundwater use in Syrdarya basin in Central Asia. With the independence of the central Asian republics, this trade-off has become a transboundary issue. Efforts to coordinate bilateral action using integrated water resources management (IWRM) principles of basin-wide cooperation have not yet yielded the hoped for results. This paper shows that there could be a ‘second best’ option of solving at least part of this transboundary problem by ‘banking’ winter flows released for hydropower production in Kyrgyzstan in the underground aquifers of Uzbekistan's Fergana Valley and extracting it for irrigation in the summer months.
Fish and ecosystem health as determined by parasite communities of lake whitefish (Coregonus clupeaformis) from Saskatchewan boreal lakes
Authors: Pietrock Michael , Hursky Olesya
Published: January 2012

In northern Canada, there is increasing concern about the potential negative impacts of industrial activities on wildlife and ecosystems. Therefore, a study was conducted on lake whitefish (Coregonus clupeaformis) from Montreal and Reindeer lakes, Saskatchewan, to assess fish health and condition, and ecosystem integrity of these northern lakes. In Montreal Lake, all fish were infected by ≥2 parasite species. The most prevalent parasite at this site was the larval trematode Ichthyocotylurus erraticus, which was detected in all fish examined. All Reindeer Lake whitefish were shown to harbour ≥1 parasite species. The most prevalent parasite (found in 87.9% of fish) at this locality was the larval trematode Diplostomum sp. Macroscopically visible pathogenic changes were not noted. Gross energy values of whitefish were 4.40 ± 0.88 MJ/kg and 5.14 ± 1.14 MJ/kg for Montreal Lake and Reindeer Lake, respectively, indicating that fish have sufficient energy stores to withstand stressful conditions. The parasite communities were species-rich and diverse, with Shannon diversity indices of 2.12 (Montreal Lake) and 2.02 (Reindeer Lake). The ratios of allogenic/autogenic as well as planktonic/benthic parasite species did not indicate atypical environmental conditions. Together the findings suggest that in both lakes there is currently no significant anthropogenic impact on the whitefish populations and ecosystem health.
Adsorption of nickel from aqueous solutions using low cost biowaste adsorbents
Authors: Singh Harminder , Rattan V. K.
Published: January 2012

This work has been carried out to check the ability of three biowastes, viz. corn cob ash (CCA), mango stone ash (MSA) and orange peel powder (OPP), to remove Ni(II) ions from aqueous solution. The surface environment of the adsorbents was characterized by Fourier transformation infrared spectroscopy and scanning electron microscopy (SEM) analysis which showed that these adsorbents contain favorable organic groups, such as, amido, amino, hydroxyls, carboxyl groups, etc., on their surface and have uniform characteristics in their surface morphology. The particle sizes for the three screened biowastes were found to be in the range of 1.5–4, 0.7–4.5 and 15–35 μm for CCA, MSA and OPP, respectively, as revealed by SEM. The effect of different system variables, viz. adsorbent dose, initial metal ion concentration and pH, were studied. Both Langmuir and Freundlich adsorption models were suitable for describing the sorption of Ni(II) on all three adsorbents used. The maximum sorption capacities of CCA, OPP and MSA used in this study were 107.4, 14.0, and 26.6 mg/g, respectively, for Ni(II) ions at optimum adsorbent dose.
Distributed urban storm water modeling within GIS integrating analytical probabilistic hydrologic models and remote sensing image analyses
Authors: Luciani Peter D. , Li James Y. , Banting Douglas
Published: January 2012

Analytical probabilistic hydrologic models (APMs) are computationally efficient producing validated storm water outputs comparable to continuous simulation for storm water planning level analyses. To date, APMs have been run as spatially lumped or semi-distributed models relying upon calibrated and spatially averaged system state variable inputs/parameters limiting model system representation and ultimately impacting model uncertainty. Here, APMs are integrated within Geographic Information Systems (GIS) and remote sensing image analyses (RSIA) deriving a planning-level distributed model under refined model system representation. The hypothesis is refinements alone, foregoing model calibration, will produce trial average annual storm water runoff volume estimates comparable to former research estimates (employing calibration) demonstrating the benefits of improved APM system representation and detail. To test the hypothesis three key system state variables – sewershed area, runoff coefficients and depression storage – are digitally extracted in GIS and RSIA through: automated delineation upon a digitally inscribed digital elevation model; unsupervised classification of an orthophotograph; and a slope-based expression, respectively. The parameters are spatially-distributed as continuous raster data layers and integrated with an APM. Spatially-distributed trial runoff volumes are within a range of 4–29% of earlier lumped/semi-distributed research estimates validating the hypothesis that further detail and physically-explicit representations of model systems improve simulation results.
Treatability study of two hybrid-passive treatment systems for landfill leachate operated at cold temperature
Authors: Speer Sean , Champagne Pascale , Anderson Bruce
Published: January 2012

Cold ambient temperatures can negatively affect the performance of passive and semi-passive landfill leachate treatment systems and decrease treatment efficiency. Cold temperature leachate treatment efficiencies were compared between a commercially available semi-passive treatment system and a passive peat and wood shaving biological trickling filter. The addition of an active fixed-film pretreatment stage in the treatment train was also assessed. Results indicated that the internal temperature of the peat filters was independent of influent water temperature; exothermic reactions maintained internal system temperatures. It was determined that pretreatment of the leachate did not affect the overall removal of chemical oxygen demand (COD), but did increase nitrification in the subsequent passive treatment systems and allowed for the removal of dissolved inorganic constituents prior to the passive treatment system, which will extend the useful life of the entire treatment train. The hybrid-passive treatment systems reduced COD concentrations by 10 ± 3% and 15 ± 3%, in the semi-passive treatment system and the peat and wood shaving biological trickling filter-based systems, respectively, and indicated that nitrifying biomass was starting to populate the treatment systems. It was therefore concluded that operation of these systems would be feasible under cold climate and should be assessed at the pilot-scale.
Correlation and prediction of azo dye degradation by nonlinear least-square regression in combined ozonation and ultrasonolysis processes
Authors: Mohajerani Masroor , Mehrvar Mehrab , Ein-Mozaffari Farhad
Published: January 2012

Correlative reaction kinetics based on nonlinear least square regression were obtained to predict the degradation of p-aminophenol (PAP), C.I. Reactive Yellow 84 (RY84), C.I. Reactive Blue 19 (RB19), and C.I. Direct Red 23 (DR23) in combined ultrasonolysis and ozonation. Effects of ultrasonolysis and ozonation as individual processes, as well as the synergetic effect for the degradation of azo dyes, were studied by linear and nonlinear regression methods. An initial dye concentration correlation index (φ) for each compound was developed to study the effects of initial concentrations of organics on their reaction rate constants. Reaction rate constants for the azo dyes’ degradation in ozonation and ultrasonolysis alone and their combination were obtained for different operating conditions. Results showed that ultrasonolysis alone was almost ineffective for decolorization and mineralization of azo dyes, but the combination of ozonation and ultrasonolysis had a significant effect on their degradation. Both ozone dose and ultrasonic density had a direct effect on the reaction rate constants, where the impact of ozone was greater with respect to that of the ultrasound. The synergetic effect of combined processes as a function of ozone concentration and ultrasound density varied from 0 to 5, 0 to 4, and 0 to 35 for RY84, RB19, and DR23, respectively.
Readiness in HIV Treatment Adherence: A Matter of Confidence. An Exploratory Study§
Authors: Sylvain Helene , Delmas Philippe
Published: January 2012

Adherence to treatment is recognized as the essence of a successful HIV combination therapy. Optimal adherence implies a readiness to begin the treatment on the part of the patient. A better understanding of the "readiness phenomenon" will become an asset for optimizing HIV treatment. However, few studies have focused on understanding the process underlying the choice to adhere. The aim of this study is to understand the readiness process that leads to adhering to the HIV treatment, from both patient and professional perspectives. Twenty-seven in-depth interviews, with a qualitative exploratory design, were the source of our data. Participants were recruited in two hospitals in Paris. Throughout the data-collection process, analysed data were supplied to all participants and the research team, thus allowing for shared constructions. Four themes, interrelated with a constitutive pattern, emerged from the data we collected. Being ready to begin and adhere to treatment is a matter of confidence in oneself, as well as in relatives, in the treatment and in the health professional team. These themes are not constant and unvarying; instead, they constitute a picture moving across time and life events. Results of this study show that adherence that goes beyond “complying with” the medical instructions, but depends on how much of an active role the patient plays in the choice to adhere.
"Implicature-Laden" Elicitations in Talk Radio Shows
Authors: Herczeg-Deli Ágnes
Published: January 2012

Indirect elicitations in talk radio programmes on BBC Radio are not uncommon, notwithstanding, misunderstanding between the host and his conversational partner is not frequent. Investigating some of the reasons this paper focuses on how the socio-cultural and cognitive factors of the context interweave in discourse. The author suggests that valid interpretation and appropriate response to inferred elicitations can be best explained within the framework of Relevance Theory, and more specifically, with the presumption of accessibility of schemas obtained from the cognitive environment of the discourse partners. Through examples of empirical research the paper aims to reveal how the mutual knowledge of the participants controls discourse via the mental processes occurring in the interaction of two minds.
Analyzing Use of “Thanks to You”: Insights for Language Teaching and Assessment in Second and Foreign Language Contexts
Authors: Lanteigne Betty , Crompton Peter
Published: January 2012

This investigation of thanks to you in British and American usage was precipitated by a situation at an American university, in which a native Arabic speaker said thanks to you in isolation, making his intended meaning unclear. The study analyzes use of thanks to you in the Corpus of Contemporary American English and the British National Corpus to gain insights for English language instruction /assessment in the American context, as well as English-as-a-lingua-franca contexts where the majority of speakers are not native speakers of English or are speakers of different varieties of English but where American or British English are for educational purposes the standard varieties. Analysis of the two corpora revealed three functions for thanks to you common to British and American usage: expressing gratitude, communicating “because of you” positively, and communicating “because of you” negatively (as in sarcasm). A fourth use of thanks to you, thanking journalists/guests for being on news programs/talk shows, occurred in the American corpus only. Analysis indicates that felicitous use of thanks to you for each of these meanings depends on the presence of a range of factors, both linguistic and material, in the context of utterance.
Repairing Tales from Japan: Changes Over Time in Personal Narratives
Authors: Riney Timothy J.
Published: January 2012

At two different times, Time 1 and Time 2, 13 participants in Japan (8 Japanese and 5 Americans) were asked to spontaneously respond in English to this prompt: “Tell me about one of the most exciting or dangerous moments in your life.” The Japanese responded during their first and fourth years of college, which involved an interval of 42 months. The Americans were native speakers of English and responded earlier and later in their one year study abroad program in Japanese language and culture. Three questions addressed by this paper were the following: (a) What types of topics and narrative structures characterize these 26 stories? (b) What types of speaker-initiated repairs appear, and are the repairs the same or different at Time 1 and Time 2? (c) How are the repairs related to different listener (American, Japanese, Filipino, and Taiwanese) assessments of the intelligibility of the narratives?
Do Marked Topics Enhance Memory?
Authors: Netz Hadar , Eviatar Zohar , Kuzar Ron
Published: January 2012

We examined the effects of markedness, the deviation from the canonical Subject-Verb-Object structure in English, on the memory of listeners for the topic of the sentence. We used three marked topic constructions: Left-Dislocation, Object-Fronting, and Subject-Marking. Sentences with these structures were inserted as the 6th item in lists of 12 canonical sentences. In all sentences the topic was the name of a man. We measured recall of the critical name. The results revealed that topics of Left-Dislocated sentences were recalled more than topics of the other constructions, with topics of Object-Fronting sentences recalled the least. We briefly discuss how sentence processing procedures might give rise to these effects.
Kinetic, Equilibrium and Thermodynamic studies on the removal of Cr(VI) by activated carbon prepared from Cajanus Cajan(L) Milsp seed shell
Authors: Thamilarasu P. , Kumar G. , Tamilarasan R. , Sivakumar V. , Karunakaran K.
Published: January 2012

Kinetic, Equilibrium and Thermodynamic studies on the removal of Cr(VI) by activated carbon prepared from Cajanus Cajan(L) Milsp seed shell

This paper presents the feasibility of the removal of hexavalent chromium ions from aqueous solutions by using activated carbon prepared from Cajanus Cajan(L) Milsp. It was carbonized and activated by treating it with concentrated sulfuric acid followed by heating for 5 h at 500°C. Batch adsorption experiments were carried out as a function of pH, contact time, initial concentration of the adsorbate, adsorbent dosage and temperature. The experimental data fitted well to the Freundlich isotherm. The thermodynamic parameters such as ΔH°, ΔS°, and ΔG° were calculated, which indicated that the adsorption was spontaneous and endothermic in nature. The adsorbent used in this study was characterized by FT-IR and SEM before and after the adsorption of metal ions. The results indicate that Cajanus Cajan(L) Milsp can be employed as a low cost alternative and commercial adsorbents in the removal of chromium (VI) from water and waste water.
Modelling of heat transfer in a packed bed column
Authors: Pianko-Oprych Paulina
Published: January 2012

Modelling of heat transfer in a packed bed column

The CFD modelling of heat transfer in the packed bed column in the laminar and turbulent flow regimes has been presented. Three numerical grids with different densities were generated for the packed bed column. The modelling was performed with the use of the Porous Media Model for treating the flow inside a porous structure. The standard k-ε model along with the logarithmic wall functions for the turbulent flow range was used. The influence of the mesh size on the accuracy of the fluid flow was studied. Both radial and axial direction temperature distributions have been compared with the experimental data1 and the values calculated from a 2DADPF model. A good agreement between the experimental and the predicted values of the pressure drop, temperature distributions and heat transfer coefficient was obtained.
Preparation and properties of porous carbon material containing magnesium oxide
Authors: Przepiórski Jacek , Czyżewski Adam , Kapica Joanna , de la Casa-Lillo Miguel
Published: January 2012

Preparation and properties of porous carbon material containing magnesium oxide

Porous carbons loaded with magnesium oxide were prepared through one-step process. Poly(ethylene terephthalate) and natural magnesite were used as carbon source and MgO precursor, respectively. An impact of a temperature and relative amounts of raw components used for preparations on the textural parameters of resulting hybrid materials is presented and discussed. As found, pore structure parameters tend to decrease along with MgO loading and temperature used during preparation process. Micropore area is the parameter being reduced primarily.