bluuebunny/crossref_metadata_2025 huggingface dataset:
Real-time Geomechanics Optimizes Drilling 4 Deep Water Wells in Kutei and Tarakan Basin - Offshore East Kalimantan
Authors: Capone Graziano , Bucari Giovanni , Bahuguna Somesh , Setiawan, Ngurah Beni
Published: January 2012

Oil and Gas exploration in deep water poses significant challenge of drilling through narrow mud weight windows with little margin for error. A thorough pre-drill planning complemented with more informed real-time risk detection and intervention while drilling the well, ensures efficient and safe drilling. This paper is a summary of one such recent successful drilling campaign.

In 2010, Eni Indonesia one of the big operators in Indonesian deep water, drilled 4 Deep water wells in varying water depths as deep as 2700ft in Kutei and Tarakan basin, offshore East Kalimantan. Real-time geomechanics services were employed to provide estimate of safe mud weight windows while drilling to the drillers. Under this service in the planning phase, pre-drill pore pressure models generated for each of the planned wells, revealed over pressured reservoirs with narrow drilling margin between pore pressure and fracture gradient. In the execution phase, a customized workflow was followed to ensure that correct pore pressure is estimated in real-time using all the available log and drilling data generated while drilling and that only properly interpreted and validated safe mud weight windows is communicated to the drilling team on board the drill-ship and town through a flag-based communication tree.

Geomechanics engineers working onboard the drill-ship ran proprietary software which streamed in real-time logging-while-drilling data – Gamma Ray, Resistivity, Density and Neutron porosity logs, caliper etc. Using these logs multiple pore pressure and fracture gradient estimates were generated in real-time. These estimates were interpreted in conjunction with drilling mechanics, mud logs, cuttings analysis, Equivalent Circulating Density and Equivalent Static Density to generate safe mud weight windows. This window was further calibrated during drilling with wireline and logging-while-drilling recorded formation pressure measurements and leak-off tests. Real-time update of safe mud weight window enabled several critical decisions like altering casing depths and mud weight management.
Introducing the Concept of Sustainable Geothermal Management in Indonesia
Authors: Amar Meutia S. , Kustino Huri
Published: January 2012

The generic issue of sustainable geothermal energy management is discussed, based on the UN principles of sustainable development, and on Indonesia’s national legal implementation mandated by the newly promulgated Act No 32/2009 and its regulatory derivatives. The development of a comprehensive assessment framework of sustainability indicators is introduced, taking into consideration economic prosperity, environment and social justice. Sustainable development as defined by the World Commission on Environment and Development is development that meets the needs of the present without compromising the ability of future generations to meet their own needs. This definition is inherently vague, and is often misunderstood or misinterpreted.

In an attempt to link sustainable development to the management of geothermal resources, two approaches are introduced: BLUE sustainability which assumes the validity of growth and places equal importance on environment, social justice and economic prosperity; and GREEN sustainability having the environment as a comprehensive baseline foundation for social justice and economic prosperity.

In simple terms, GREEN sustainability focuses on the capacity of any given geothermal system to sustain exploitation, whereas BLUE sustainability focuses on economic forces and technological advances. The basic framework of P3 (People, Planet and Profit) is utilized to explore an equilibrium model for a typical geothermal energy project, using indicators for social, business/economics and the environment derived from the Global Sustainability Reporting Initiatives.
New Openhole Technology Unlocks Unconventional Oil and Gas Reserves Worldwide.
Authors: Rivenbark Mark , Dickenson Robert Wayne
Published: January 2012

Open hole, multi-stage (OHMS) fracturing systems were introduced in 2001. Since then, this technology has been credited with unlocking oil and gas reserves around the world that were previously dismissed as unavailable or uneconomic, enabling companies to maximize production in tight rock formations and mature oil fields. OHMS systems have been run in every type of formation from the much heralded shale gas plays in North America to the massive carbonate formations in Saudi Arabia and have also been used in offshore wells in the North Sea, Black Sea and West Africa.

This paper focuses on the open hole packer used in OHMS systems to generate the annular compartmentalization necessary for effective multi-stage stimulation and production. This packer is a dual element, hydraulic-set, mechanical (DHM) packer and provides reliable open hole isolation with various benefits compared to swellable, inflatable and other mechanical packers including: 1) Reduced torque and drag due to their short length (average 5 ft) with only two short sections of rubber with a minimum running outside diameter, 2) Creation of two independent sealing points via dual elements, which together act like a single, 3 ft long seal with redundant sealing, 3) No need to formulate them for specific downhole fluids or wait for them to swell, 4) No thermal contraction such that the seal is not lost during stimulation, and 5) The rubber element does not reduce its durometer rating when set.

Laboratory testing and field applications of the DHM packer are presented including HPHT, multi-laterals, proppant fracturing and acid stimulation with on and offshore case histories incorporating stand alone screens, acid jets, fracture ports and combinations thereof.
Wellbore Stability Analysis in the South China Sea: A Case Study
Authors: Cai Jun , Shao Shijun , Zhang Chao , Qiu Kaibin
Published: January 2012

The paper describes a case study in the South China Sea in which drilling problems were successfully addressed through a wellbore stability analysis. The wellbore stability analysis started from understanding of the drilling history of offset wells. A specially designed drilling event review plot, which categorizes and organizes all drilling problems in a graphical display, was used as to illustrate drilling and borehole failure history for the two offset wells in the study area. A mechanical earth model was constructed by following a systematical workflow with emphasis on reducing uncertainty of the in-situ stresses. The synthetic borehole failure image was used to provide an excellent visualization of borehole failure forecast, which made it easily understandable even for geomechanics non-experts and was comparable to the borehole failure observations from caliper logs and borehole image data. A drilling map was constructed to provide a user-friendly presentation of the outcome of the wellbore stability analysis. This improved the communication among all drilling stakeholders. Based on the results provided from the analysis, engineers revised the setting depth for 9 5/8-in. casing to reduce drilling risk. Post-drilling analysis showed that there was substantial improvement in the subsequent drilling performance for the planned well compared to that for the previous wells.

This paper illustrates that incorporating wellbore stability analysis as part of the well planning process allows the drilling team to optimize the casing design and drilling mud weight to minimize wellbore instability and improve drilling performance.
A Strategic Method to Accelerate Individual’s Learning and Enhance Subsurface Team Performance within Multidisciplinary and Multi-generational Environments
Authors: Dashti Qasem , Gunawan Christine
Published: January 2012

The development of young geoscientists and engineers to be independent contributors is paramount for Kuwait Oil Company’s long-term success in optimizing their production and improving field development efficiency. In our fields, main challenges are characterized by the deep and tight naturally fractured carbonate reservoirs, volatile fluids, high pressure high temperature conditions and the presence of CO2 and sour gas.

Production enhancement activities play a significant role in maintaining production capacity. Therefore, rapid and integrated decisions from multidisciplinary teams are necessary to select potential solutions and to accelerate the required remedial work. Yet the largely junior population of the asset teams creates an immense challenge in getting the work completed.

Overcoming this challenge begins by developing individual staff learning programs that are aligned with competency gaps, business needs and personal development plans. The program lists the competencies required, which are then achieved through blended learning. The learning program emphasizes transferring knowledge and skills on the job, and holds the learner accountable for achieving results. Therefore, linking training with relevant and appropriate task assignments is essential to accelerate and reinforce competency development. One task which has proven key in the blended learning methodology is conducting formal and detailed well reviews, in which all pertinent data is presented on a specific well, and a multi-disciplinary team brainstorms and recommends an action plan and the additional. Staff assigned to conduct well reviews must develop knowledge outside their domain in order to facilitate team collaboration among the different disciplines, allowing the sharing of best practices and optimum decision making.

This accelerated staff development method has been applied for two years in North Kuwait and has resulted in meeting our production goals, better field management and improved team performance. Some examples of activities enabled by this methodology are defining perforation intervals, developing sector reservoir models to determine shut-in periods required for buildup testing, and formulating workover program design. In these two years 12 workover programs have been completed successfully – is an outcome of 66 well reviews. Just as importantly, junior staff competency grew 48%, an achievement which is mainly the result of their being assigned and performing jobs such as well data analysis and well reviews with minimum supervision.

This paper details the method and progress of what has proven to be the best approach to accelerating staff learning curves, reducing competency gaps and enhancing professional development that delivers. Also summarized is the value of team collaboration, interaction between engineers and geosciences for successful reservoir management, and lessons learned.
Impact of Electrical Surface Charges and Cation Exchange on Oil Recovery by Low Salinity Water
Authors: Nasralla Ramez A. , Nasr-El-Din Hisham A.
Published: January 2012

Low salinity water is a promising technique for improving oil recovery in sandstone reservoirs. However, the mechanisms of low salinity water are still uncertain; that makes the optimum conditions are unknown. In this paper, we study the effect of cation type and concentration in the injected water to identify the optimum salinity. Coreflood experiments of waterflooding and cation exchange tests were conducted to investigate the impact of cations on oil recovery, and understand the rock/brine interactions. In addition, zeta potential at oil/brine and rock/brine interfaces were measured to examine how the cation type and concentration change the electrical surface charges, and relate these measurements to the oil recovery obtained from coreflood.

Berea sandstone cores were used for waterflooding and cation exchange experiments; all coreflood experiments run at HPHT. Three concentrations of NaCl, CaCl2, and MgCl2 were tested with two crude oils of different compositions and properties. ICP-OES, and a spectrophotometer were used to analyze the ions concentrations in the effluent fluids for both waterflooding and cation exchange tests. Zeta potential was measured for solutions of oil/brine, and solid/brine; the solids used were Berea sandstone and four types of clays.

This work contributes to the understandings of the impact of electrical surface charge and cation exchange on oil recovery by low salinity waterflooding. Zeta potential results showed that Na+ changes the electrical charge at both oil/brine and rock/brine interface to highly negative, which results in repulsion forces between the two interfaces, and hence wettability alteration and improvement in oil recovery. Moreover, waterflood experiments of NaCl solutions improved oil recovery significantly compared to CaCl2, and MgCl2. Analysis of core effluent fluid proved the interaction between brine and rock; injection of single cation brine leached some of the ions from the rock surface by exchanging cations, which could contribute to improvement of oil recovery. Results demonstrate that the existing cations in the injected water brine have more dominant effect on the recovery factor than the water salinity. These findings can help in defining the brines that have higher potential for oil recovery improvement.
Maari Field Development – Case Study
Authors: Mills C. R. , Marron A. , Leeb W. J.
Published: January 2012

The Maari Field in the offshore Taranaki Basin, New Zealand was discovered in 1983 by the Moki-1 exploration well (figure 1). Appraisal activities and development studies undertaken by various oil companies over the subsequent two decades failed to identify a viable development concept with an acceptable risk profile. Key factors delaying development were distance from existing infrastructure, field size in association with oil price and critically the high wax / low pour point nature of the oil. The Maari Joint Venture identified a strategy to develop the field and produce the previously stranded oil by means of innovative technology applications.

The self-installing wellhead platform and the FPSO were installed in April and May 2008, respectively but the jack-up rig to drill the five horizontal production and three deviated water injection wells was delayed by three months due to winter weather. First Oil from the field was on 25th February 2009, a milestone achieved some 25 years after its discovery.

A number of new technologies and pioneering applications were put into practice with the Maari field development: The self installing wellhead platform. At the time Maari WHP was the largest self-installing platform of its kind.The production wells have a thermal design with both passive (thermal gel and thermal cement in the annuli) and active (electric down hole heating system) elements.Drilling while casing.The electric submersible pump assemblies were designed to handle free gas conditions down hole in the horizontal section due to the reservoir fluid being close to its bubble point.The injection water is heated to reservoir temperature to avoid wax precipitation in the reservoir and injected above the ‘fracture pressure’.

Two smaller near field satellite oil accumulations were also drilled and completed, including a ~8,000m horizontal ERD production well targeting a deeper reservoir in separate structure to the south of Maari. Numerous challenges, such as scale, hydrogen sulphide, corrosion, completion designs and wax, have been encountered and largely overcome during the production phase.

The paper will detail the innovations, new technologies, major learnings and experiences from the development concepts to production of this originally ‘stranded’ asset.
An Integrated Petrophysical Analysis to Evaluate Sequence Stratigraphy of the Winduck Interval in the Neckarboo Sub-basin, Darling Basin, NSW
Authors: Khalifa Mohamed , Alta’ee Ali F.
Published: January 2012

The latest Silurian to Early Devonian Winduck Interval of the extensive but poorly exposed Neckarboo Sub-basin, consists of several thousands of metres of a quartzose siliciclastic sandstone succession that has been divided into three sequence divisions called (in ascending parasequence order) parasequence A (coarse-grained quartz sandstone), parasequence B (fining-upward succession of sandstone with siltstone and sandstone beds thicken upward) and parasequence C (coarse-grained quartz sandstone with siltstone and interbedded calcareous sandstones). These three geophysically defined parasequences are separated by slightly discordant erosion surfaces. The erosion surfaces are characterised by abrupt breaks at the top of parasequences A and B and the surface at the top of parasequence B represents relatively local erosion. The top of parasequence C is marked by a major unconformity with the Snake Cave Interval. Gamma ray and self-potential signatures within the parasequences can be correlated throughout the Neckarboo Sub-basin. The three sequence divisions are further subdivided into depositional parasequences, which are readily recognised from core sedimentology and electrofacies analysis. The parasequences provide the framework for a detailed sedimentological analysis, which focuses on the identification of lithofacies successions and parasequences. Petrophysical data are recorded and their relationships to the depositional parasequences are discussed. This paper presents a predictive reservoir effectiveness model that has been developed to aid exploration of the Winduck Interval. The aim is to find the distribution of parasequences (based on variations in porosity, net effective thickness and lithofacies with burial depth) and to provide a dataset for lithostratigraphic units within the Winduck Interval and parameter input for exploration prospect evaluation. Parasequence stratigraphic analyses were obtained where there is good lithofacies control. The porosity and permeability results have been analyzed in a number of parasequences and poor reservoir quality may be due to the effects of structure and fluid flow. This approach provides for better and more precise stratigraphic trap analysis.
The Role of Society of Indonesian Petroleum Engineers (IATMI) as a Professional Organization in Stimulating a Synergism of the Academy-Business-Government (ABG) Relationship in Oil and Gas Sector in Indonesia
Authors: Aprilian Salis , Adisoemarta P. Suryono , Ismanto Bambang
Published: January 2012

The three pillars of main activity on oil and gas sectors are the ABG (Academy (university), Business entity (company), and the Government). A synergism of these three pillars should be strengthening in building a sustainable growth of oil and gas business.

The relationship could be in any activities amongst them, such as the universities are supporting the intake of workforces and well trained developing people for the industry (company). The companies accept the graduated students and give a sponsorship for the research in the university. The government produces the rules for business and support funds for the university.

As a professional organization IATMI (Society of Indonesia Petroleum Engineers) tried to stimulate a better relationship among the A-B-G. IATMI had continuous linked activities between the universities and the companies which is a bridging program for graduate students to have information of job fair, scholarship, or research grants. The IATMI also support the company to have a better access for new research and technology development in the universities, socialization of new regulations and policies from the government, etc.

This paper reviews the role of IATMI as an experienced professional organization in Indonesia’s oil gas sectors. The discussion will focus on how important of a synergism among the ABG and the results of the IATMI initiatives in last decade supporting and stimulating the business of oil and gas in Indonesia.
Oil and Gas Industry Driven Academic Research
Authors: Siregar Septoratno , Darmadi Darmadi , Soekarno Pudjo , Soewono Edy , Mucharam Leksono , Sidarto Kuntjoro Adji , Gunawan Agus Yodi , Priharto Neil , Swadesi Boni
Published: January 2012

Academic research is not often considered as a high priority in any industry since it does not always deliver clear results in a short term, although a considerably large sum of funds is spent on highly educated, thus costly human resources. However, research activities have to be performed. On the other hand, education process in universities has to deliver good human resources to run delicate operations such as in oil and gas industries. An attempt was initiated at ITB to meet the oil and gas industry needs for both good university graduates and answers to their problems. A Research Consortium, namely Optimization in Pipeline Network (OPPINET) was established in the year 2001. Establishment of OPPINET motivated at the time of by a development plan of an integrated national gas pipeline network (Indonesian Grid) and the ASEAN Grid, and even the Asia Grid. Constructions of pipeline are very expensive so they need to be optimized in such a way that the development provides economic benefits for shareholders and provide maximum benefit for society and the state. The number of member participants grew from three at its inception to nine members during a period of ten years. A number of topics, which are proposed by the member companies have been investigated, e.g., pipe route, pipe size, compressor and pump size optimization, flow assurance, debottlenecking, leak detection, oil pipe heater positioning, toll fee calculation. Three years later, another research consortium, Oil and Gas Recovery for Indonesia (OGRINDO) was established based on the needs in Indonesian oil and gas industries to improve oil recovery and production, including the rejuvenation of old and marginal fields. Differing from OPPINET, OGRINDO was directed to conduct technical and economic feasibility by setting up predictive model, simulation and necessary laboratory experiments for appropriate techniques in oil recovery for Indonesian oil fields which inflict minimal or no harm on the environment. The topics of OGRINDO include EOR Screening, Water Injection, Chemical (Polymer, Surfactant) Injection, Air Injection, Nitrogen Injection, Microbial EOR, Sand Control, Vibro seismic. The contributions of OPPINET and OGRINDO to the oil industry have been appreciated by the government of Indonesia, business people and academia. Besides providing answers to oil and gas industry problems, both research consortia deliver graduates at Bachelor, Master and Doctorate degrees who are knowledgeable about oil and gas industry real problems. In addition, a number of computer software programs have been developed, some of them have acquired copy right.
Linking resource users' perceptions and collective action in commons management – an examination of water supply systems in Southern Senegal
Authors: Hanatani Atsushi , Fuse Kana
Published: January 2012

Poor maintenance of water supply systems is a critical issue in sub-Saharan Africa. Using survey data on users of motorized piped water supply systems in rural southern Senegal, this paper examines what motivates resource users to contribute financially to the management of water supply system infrastructure by paying their water tariff. Results from logistic regression analysis indicate that users who prefer borehole water and are satisfied with the service provided are more likely than others to pay. In addition, those who trust that other users will pay are more likely themselves to pay than those who do not trust their peers. These findings suggest that assessing the needs of users and providing services tailored to those needs (e.g., quality, convenience) is recommended for future interventions. The incorporation of programs that promote peer trust should also be considered as future interventions to establish or strengthen resource management organization.
Freshwater, climate change and adaptation in the Ganges River Basin
Authors: Hosterman Heather R. , McCornick Peter G. , Kistin Elizabeth J. , Sharma Bharat , Bharati Luna
Published: January 2012

Climate change is one of the drivers of change in the Ganges River Basin, together with population growth, economic development and water management practices. These changing circumstances have a significant impact on key social and economic sectors of the basin, largely through changes in water quantity, quality and timing of availability. This paper evaluates the impact of water on changing circumstances in three sectors of the Ganges Basin – agriculture, ecosystems and energy. Given the inherent interconnectedness of these core sectors and the cross-cutting impact of changing circumstances on water resources, we argue that adaptation should not be viewed as a separate initiative, but rather as a goal and perspective incorporated into every level of planning and decision making. Adaptation to changing circumstances will need to be closely linked to water resource management and will require significant collaboration across the sectors.
Agriculture and economics in the Water Framework Directive: progress and limitations
Authors: Gómez-Limón J. A. , Riesgo L.
Published: January 2012

Agriculture is having an increasing impact on water resources in Spain, both from a quantitative (consumption) and qualitative (pollution) perspective. Therefore, the implementation of the Water Framework Directive (WFD) will have a great impact on this sector. In fact, new river management plans aim to reduce these pressures through the implementation of programmes of measures. These instruments will impose new requirements (costs) on farming systems and may promote the adoption of more efficient and sustainable production methods. Within this context this paper aims to analyse how this new water management plan is being developed. An economic analysis is carried out to select a programme of measures involving irrigated agriculture.
Decentralisation, HRD and production efficiency of water utilities: evidence from India
Authors: Asthana Anand N.
Published: January 2012

Decentralisation of water supplies in developing countries is being promoted by international aid agencies. It is argued that decentralisation by a government close to the people will generate better project performance. This article compares the performance of piped water supply schemes run by the state governments and local government in central India and finds that the latter are running less efficiently than the former. It finds that a serious drawback of decentralisation is the neglect of human resource development (HRD). Empirical analysis shows that this neglect lowers production efficiency. Thus, decentralisation has a negative effect on production efficiency, directly as well as through lower HRD. Government ‘closer to the people’ may not necessarily be better suited to provide water supply services.
Water policy development and governance in the Caribbean: an overview of regional progress
Authors: Cashman Adrian C.
Published: January 2012

Water management institutions and arrangements in many Caribbean states have not, until recently, altered substantially for some sixty years with the current arrangements reflecting the predominant governance paradigm of a transitional colonial era. This is most obvious in the continuance of a sectoral approach to what might be referred to as the business of government. This, however, is beginning to change such that the water sector in the Caribbean region exhibits varying stages of institutional re-ordering as it seeks to respond to challenges of increasing demand on and for water. This paper reviews the institutional status of water management and water policy developments in the Caribbean through examples from fifteen English-speaking Caribbean states. The trends and influences that are contributing to policy change and governance responses are examined and critiqued, in order to explore where and what potential tensions the re-ordering might give rise to.
Ecological ambitions and complications in the regional implementation of the Water Framework Directive in the Netherlands
Authors: Dieperink C. , Raadgever G. T. , Driessen P. P. J. , Smit A. A. H. , van Rijswick H. F. M. W.
Published: January 2012

The Water Framework Directive has introduced a new governance approach that offers implementing agencies in EU Member States policy discretion to implement ecological ambitions. The aim of this paper was to gain insight into the way regional actors use this discretion and into the rationale behind their behaviour. Our research revealed that in regional implementation processes in the Netherlands, limited ecological ambitions have been framed due to several complications. These complications also occur in other EU Member States. As it might be possible to reduce some of the complications by improving collaboration, exchange and learning between the actors involved, the paper concludes by outlining the important role that communities of practice might play in the implementation process of water policy at the regional level.
Colour removal and the effect of reactive dyes on acid producing anaerobic microorganisms
Authors: Bhattacharyya Debraj , Singh Kripa S.
Published: January 2012

The cultures from a sucrose-fed anaerobic acid reactor were dosed with 0, 60, 100, 200, 400, 800 and 1,500 mg/L, of a mixture of three Procion reactive dyes, Red MX-8B, Red MX-5B and Orange MX-2R, in order to study the colour removal and the toxic effect of the dyes on anaerobic acidification of sucrose. Sucrose undergoes a possible extracellular transformation into intermediate substances before being taken up by the acidogens for volatile fatty acid (VFA) synthesis. The rate and the extent of this uptake is unaffected by the presence of dyes. The dyes, however, reduced the rate of synthesis of VFA, and considerably diminished the VFA production potential of sucrose. The acidification stopped, likely due to an inhibition caused by VFA accumulation. As a result, only 50–60% of the soluble organic carbon was utilised for VFA synthesis. The removal of colour by the unacclimated anaerobic acidogenic biomass takes place by adsorption. However, Freundlich's adsorption constants did not suggest a favourable adsorption.
Disinfection by-products in drinking water – a case study on Calgary, Alberta, Canada
Authors: Chen Mei , Ohman Klas , Sinclair Jason , Petkau Darcy , Yau Raymond , Deng Jian Fu , Tran Thien , Huston Chris , Elford Tom
Published: January 2012

Disinfection by-products (DBPs) have been monitored in Calgary's drinking water for approximately 15 years. The variability of the DBPs has typically exhibited similar patterns over the period of monitoring. Due to the nature of the surface waters supplying the water treatment plants, the level of DBPs was largely influenced by surface runoff events where the level of natural organic matter (NOM) increased, which was characterized by a relatively high total organic carbon (TOC) content. Principal component analysis (PCA) was utilized for this study to quickly identify the key underlying correlations present within the very large, complex multivariate data matrix. Apart from TOC, chlorine demand, chlorine residual and temperature were observed to correlate with the formation of DBPs in the finished drinking water. In addition to TOC, PCA also indicates that pH and temperature in the distribution system could have an influence on the variability of DBPs in Calgary's drinking water. It was apparent that upgrades to the water treatment systems in Calgary have resulted in an improved removal of DBP precursors such as NOM prior to chlorination, which is a key factor in reducing the DBP levels in the drinking water, thereby providing an enhanced level of public health protection.
Élimination des ions Cu(II) d'une solution aqueuse par les micro-particules de la plante Carpobrotus edulis en système dynamiqueRemoval of Cu(II) ions from aqueous solution by micro-particles of dried Carpobrotus edulis plant in a column system
Authors: Chiban Mohamed , Sinan Fouad
Published: January 2012

This study reports on the removal of Cu(II) ions from an aqueous solution by adsorption onto dried Carpobrotus edulis plant in a column system. The effect of various process parameters, namely m/V ratio, contact time, initial Cu(II) concentration and pH was studied. The experimental data were analyzed using Freundlich and Langmuir isotherm models to determine the mechanistic parameters related to the adsorption process. The results showed that the adsorption of Cu(II) ions by dried C. edulis increases with the increase of contact time, adsorbent dose, pH and initial Cu(II) concentration in the solution. The maximum adsorption of Cu(II) is reached after one hour of contact time at initial copper concentrations ranging between 10 and 100 mg/L. The m/V ratio of 25 g/L was optimal to obtain a maximum adsorption of copper ions. The maximum adsorption percentage of C. edulis is equal to 94.4%. These results showed that the dried C. edulis plant could be considered as a potential adsorbent material for the removal of Cu(II) from wastewater, using a column adsorption mode.
Short Peptides as Inhibitors of Amyloid Aggregation
Authors: Neddenriep Bradley , Calciano Anastasia , Conti Daniel , Sauve Erin , Paterson Marissa , Bruno Edward , A. Moffet David
Published: January 2012

The misfolding and aggregation of proteins into amyloid has been linked to a variety of age-related diseases.
Aggregation of proteins, such as Aβ in Alzheimer's disease and Islet Amyloid Polypeptide (IAPP, amylin) in type 2 diabetes,
appears to lead to the formation of toxic assemblies. These assemblies range in size from small oligomers (2-8 proteins)
to large fibrils (thousands of proteins). It remains unclear how these amyloidogenic proteins misfold and form toxic
species, but growing evidence suggests that inhibiting the aggregation of these proteins could slow, if not prevent altogether,
the progression of these diseases. We describe the use of small peptides (<43 amino acids) as inhibitors of amyloid-
based aggregation. These peptides, often short complementary segments of the amyloid proteins, can be useful (i) for
identifying the aggregation-prone regions of the amyloid proteins (ii) as models for drug discovery and (iii) as potential
therapeutic agents themselves.
Continuous Positive Airway Pressure Treatment: Effect on Serum Lipids in Patients with Obstructive Sleep Apnoea
Authors: Michailidis Vassileios , Steiropoulos Paschalis , Nena Evangelia , Papanas Nikolaos , Maltezos Efstratios , Bouros Demosthenes
Published: January 2012

Obstructive Sleep Apnoea (OSA) is a common disorder in adults. Its hallmark is repetitive episodes of partial or complete obstruction of the upper airway during sleep associated with increasing respiratory efforts. This leads to oxyhaemoglobin desaturation, sleep fragmentation, and daytime symptoms, mainly excessive sleepiness. Accumulating
evidence suggests that intermittent hypoxia and oxyhaemoglobin desaturation may, irrespective of obesity, lead to elevation of serum lipids even in non-dyslipidaemic OSA patients. Continuous Positive Airway Pressure (CPAP) is the treatment of choice for OSA, since it eliminates upper airway collapse during sleep and improves sleep fragmentation, daytime symptoms and quality of life. Moreover, it has been proposed that the amelioration of breathing disturbances during
sleep can improve several markers of the lipid profile, such as total cholesterol, triglycerides, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol as well as apolipoproteins A, B and C. Indeed, some studies have reported improvements in these parameters especially in CPAP adherent patients. However, other studies failed to confirm this beneficial effect. The present article reviews the issue whether CPAP treatment exerts a beneficial effect on lipids.
Trends in the Treatment of Anemia Using Recombinant Human Erythropoietin in Patients with HIV Infection
Authors: Sullivan Patrick S , Hanson Debra L , Richardson James T , Brooks John T
Published: January 2012

Background:

Treating anemia with erythropoietin (EPO) to hemoglobin (Hb) endpoints >11 g/dL may increase risk of serious adverse cardiovascular events.

Methods:

We used medical records data (1996-2003 from the Adolescent Spectrum of HIV Disease Project [ASD] and 1996-2006 from the HIV Outpatient Study [HOPS]) to describe EPO prescription patterns for mildly, moderately, or severely anemic HIV-infected patients. We calculated proportions prescribed EPO and treated to Hb>12 g/dL, and tested for trends over time. We calculated median hemoglobin at first EPO prescription, and described temporal changes using linear regression.

Results:

Among 37,395 patients in ASD and 7,005 patients in HOPS, EPO prescription increased over time for moderately anemic patients; for patients with severe anemia, EPO prescription increased only among ASD patients. Hb at EPO prescription decreased over time in ASD patients (median=8.5 g/dL), but not in HOPS patients (median 9.5 g/dL). Percentage of EPO-treated patients with post-treatment Hb>12 g/dL was 18.3% in ASD and stable, and was 56.7% in HOPS and increased over time (p = 0.03).

Conclusions:

Through 2006, EPO prescription increased over time for patients with moderate or severe anemia. Many patients treated with EPO had post-treatment Hb>12 g/dL. Based on 2011 FDA recommendations, changes in previous prescription practices will be needed.
Comparative Study on Faecal Contamination and Occurrence of Salmonella spp. and Vibrio parahaemolyticus in Two Species of Shellfish in Morocco
Authors: Boutaib Rachid , Marhraoui Mohamed , Karim Oulad Abdellah Mohamed , Bouchrif Brahim
Published: January 2012

Background:

Analysis of bivalves for microbial bacteria is a tool for sanitary control. Methodology: 104
samples of bivalves made up of smooth Venus (Callista chione) and red cockles (Acanthocardia tuberculatum) were
analysed for Escherichia coli by using MPN technique and for Salmonella by method ISO 6579 and Vibrio
parahaemolyticus, analysed biochemically and by multiplex PCR.

Results and Conclusions:

Seasonal variation of faecal contamination was observed between wet and dry periods in three
locations. Prevalence of Salmonella was 8.6% and onto 47 strains isolated, three serotypes groups were identified as: S.
Kentucky, S. Newport and S. Glostrup. Regarding Vibrio parahaemolyticus, prevalence was 8.6% with 24 isolates
identified and confirmed by multiplex PCR as tdh and trh negatives.
CO2 Emissions and Productivity in APEC Member Economies
Authors: Ke Tsz-Yi , Hu Jin-Li
Published: January 2012

Global warming is one of the most important issues globally. In 1997 the Kyoto Protocol regulated the
greenhouse gas reduction obligation of developed economies. This study takes carbon dioxide as an undesirable output
and respectively uses Malmquist and Malmquist-Luenberger indices to compute the productivity change of APEC
member economies. A panel dataset of 15 APEC economies from 1995 to 2003 is constructed. Developed economies
have higher productivity if CO2 emission is not considered in the Malmquist index. Since developed economies face
stricter CO2 abatement obligations, they have lower productivity than developing nations if the CO2 abatement is taken
into account in the Malmquist-Luenberger index. This study has found that, in terms of the Malmquist productivity index,
the average productivity indices and technical changes of 15 economies generally regressed during the observation period.
There are productivity improvements in Oceania and Central and South America. In terms of the degree of development,
the productivity of developed economies is superior to that of developing economies. Developed economies have
generally accepted higher productivity while disregarding CO2 emission.
The Effect of Content Instruction in L2 on L1 Pragmatics
Authors: Kanik Mehmet
Published: January 2012

This study investigates whether content instruction in English has an impact on L1 pragmatics. In this study a discourse completion test with eight request situations in Turkish was given to three groups of Turkish students enrolled in undergraduate programs in a faculty of education in Turkey. One group of students received most of their education in English. The other two groups received their education in Turkish. An interesting finding is that the differences in the make-up of the situations were only observed in situations with high imposition. This shows that instruction in the foreign language has an impact on sociopragmatic interpretation in L1. Overall, the results reveal that instruction in foreign language has an impact on first language pragmatic use.
The Effects of a Combined Output and Input-Oriented Approach in Teaching Reported Speech
Authors: Mystkowska-Wiertelak Anna
Published: January 2012

The author of the present study investigates the effects of output and input-oriented treatment on the acquisition of English reported speech, a complex phenomenon posing considerable difficulty even to more advanced learners of the language. The study focuses on two research questions:

Will there be any differences in how learners exposed to reception-oriented, production-oriented and a combined type instructional treatments interpret and produce sentences containing reported speech?

Is the effect durable, as measured on immediate and delayed post-tests?

The participants of the study are 74 first year students of the English philology who were divided into four groups: 3 treatment groups and a control one. The study results do not mirror those reported in the vast majority of relevant literature and points that although input manipulation appears to have more beneficial effect on the development of the interlanguage than the analysis of output, a combination of the two approaches turns out to be the most beneficial and economical.
Temporal Inferences in Conversation
Authors: Paul Christine
Published: January 2012

Within this article, I explore how coproductions (expansions made by a second speaker upon a previous utterance) and questions regarding prior utterances work to verbalize inferences regarding the temporal information in spoken German conversation. While questions regarding prior utterances and coproductions are traditionally understood to have different communicative functions (signaling understanding/ misunderstanding; turn taking) to coproductions, empirical data shows how these expression types enable the speaker to gradually verbalize different strengths of assumption about details of the previous turn. These two expression types are not a dichotomy, but a continuum.
New photocatalyst for decomposition of humic acids in photocatalysis and photo-Fenton processes
Authors: Tryba B. , Brożek P. , Piszcz M. , Morawski A.
Published: January 2012

New photocatalyst for decomposition of humic acids in photocatalysis and photo-Fenton processes

Humic acid Leonardite IHSS standard was decomposed on TiO2 and TiO2 modified by FeC2O4 via the photocatalysis and photo-Fenton processes under UV irradiation. Humic acid (HA) were favorable adsorbed on TiO2 surface and followed decomposition during UV irradiation faster on TiO2 than on the modified samples. However, when H2O2 was added to the solution, the photo-Fenton process occurred on the prepared TiO2 samples, contained iron together with photocatalysis and high acceleration of HA decomposition was observed. In this case the mineralization degree was much higher than in the applied photocatalysis only, around 75% HA (with concentration of 18 mg/L) was mineralized after 3 h of adsorption and 5 h of UV irradiation in the presence of H2O2 and modified TiO2 whereas on TiO2 mineralisation of HA occurred in around 45% only. The measured fluorescence spectra of HA solutions showed that in the presence of H2O2 polycyclic aromatics were rapidly oxidized to the lower size products such as alcohols, aldehydes, ketones and carboxylic acids, what accelerated the process of HA decomposition.
Immobilization of Aspergillus oryzae β galactosidase on concanavalin A-layered calcium alginate-cellulose beads and its application in lactose hydrolysis in continuous spiral bed reactors
Authors: Ansari Shakeel , Husain Qayyum
Published: January 2012

Immobilization of Aspergillus oryzae β galactosidase on concanavalin A-layered calcium alginate-cellulose beads and its application in lactose hydrolysis in continuous spiral bed reactors

In this study, Aspergillus oryzae β galactosidase was immobilized on concanavalin A layered calcium alginate-cellulose beads as a bioaffinity support. Immobilized enzyme showed a remarkable broadening in temperature-activity profiles as compared to the native enzyme and exhibited 65% activity in the presence of 5% galactose. Michaelis constant (Km) was 2.57 mM and 5.38 mM for the free and the immobilized β galactosidase, respectively. Crosslinked β galactosidase showed greater catalytic activity in the presence of Mg2+ and was more stable during storage at 4°C for 6 weeks. Immobilized enzyme hydrolyzed 67% lactose in milk in 8 h and 85% lactose in whey in 9 h in the stirred batch process at 50°C. The continuous hydrolysis of lactose by crosslinked β galactosidase in spiral bed reactor exhibited 93% and 88% hydrolysis of lactose at flow rate of 20 ml/h and 30 ml/h, after 1 month operation, respectively.
Influence of wet chemistry treatment on the mechanical performance of natural fibres
Authors: Koziol Mateusz , Bogdan-Wlodek Aleksandra , Myalski Jerzy , Wieczorek Jakub
Published: January 2012

Influence of wet chemistry treatment on the mechanical performance of natural fibres

The paper presents determination of the effect of various chemical treatment on the strength of 288 tex jute yarn arisen from the plain weave fabric produced by LENTEX, Poland. The yarn was put to alternative treatments in: NaOH and KOH water solutions with various concentration (from 1 to 15%) and treatment duration (from 0.5 to 6 hours), vinyl acetate, methanol and toluene diisocyanate. After the treatment it was put to tensile tests. Yarn diameter and elementary fibre twist angle were also measured using MICRO PROF FRT optical profilographometer. The SEM micro-photographs have also been performed in order to evaluate the structural changes of the yarn after the treatment.

Optimal conditions of alcali-treatment are: 5% concentration and 2h duration for NaOH, 3% concentration and 4h duration for KOH. Such treatments give a growth in yarn rupture force up to 10% and they are well applicable in composite materials manufacturing. Also interaction with vinyl acetate and toluene diisocyanate has practically not negative influence on the mechanical performance of the yarn. Two effects were observed which can explain the influence of chemical treatment on mechanical performance of jute yarn: swelling and change in the orientation of elementary fibres.
Attachment of 2,2-bipyridine onto a silica gel for application as a sequestering agent for copper, cadmium and lead ions from an aqueous medium
Authors: Souza Elton , Cristante Valtair , Padilha Pedro , Jorge Sonia , Martines Marco , Silva Rafael , Carmo Devaney , Castro Gustavo
Published: January 2012

Attachment of 2,2-bipyridine onto a silica gel for application as a sequestering agent for copper, cadmium and lead ions from an aqueous medium

A method was developed to attach 2,2-bipyridine (BP) onto a silica gel surface by a two-step reaction. The first step consisted of a reaction between the matrix and a silylating agent, 3-chloropropyltrimethoxysilane. In the second step of the reaction, a ligand molecule was attached onto Si-CPTS, yielding the product Si-BP. The modified material contained 0.431±0.01 mmol of 2,2-bipyridine per gram of modified silica, as confirmed by FT-IR spectra of the proposed structure. The surface modification was characterized by the BET technique, which revealed a decrease in the surface area from 614 to 450 m2 g-1. The series of adsorption isotherms for the metal ions were adjusted to fit a modified Langmuir equation. The maximum number of moles of copper, cadmium and lead ions adsorbed was 0.64, 0.53, and 0.54 mmol g-1, respectively. The surface saturation was calculated as φ fraction and the values obtained, Cu(II) = 1.160, Cd(II) = 1.044 and Pb(II) = 0.997, suggest a type 1:1 metal-ligand complex.