bluuebunny/crossref_metadata_2025 huggingface dataset:
Seawater Injection into Clastic Formations: Formation Damage Investigation Using Simulation and Coreflood Studies
Authors: Al-Mohammad Abdullah M. , Al-Khaldi Mohammad H. , Al-Yami Ibrahim S.
Published: May 2012

Waterflooding in different reservoirs for pressure maintenance and recovering more oil is a well established practice in the oil industry. Many research studies have shown that the success of any waterflooding process is mainly dependent on both physicochemical (fluid-rock) and geochemical (fluid-fluid) interactions. These interactions have been extensively investigated during seawater injection into carbonate formations. However, the rock/seawater chemical interactions are completely different in sandstone than in carbonate formations, due to different rock mineralogy. Therefore, the main objective of this paper is to investigate both the potential physicochemical and geochemical formation damage mechanisms that might occur during injection of seawater into a central Arabia sandstone formation.

Scaling potential due to seawater-produced brine chemical interactions was investigated at an average reservoir temperature of 186°F, based on the Pitzer theory of electrolytes. In addition to the prediction data, laboratory compatibility tests were conducted to investigate the scaling potential in different seawater/produced brine mixtures at reservoir temperature. Since this sandstone formation contained different clays, such as illite and smectite, the clay swelling and fines migration tendency was explored using coreflood setup and zeta potential technique.

The saturation index (SI) of different scales, such as calcium carbonate and calcium sulfate, was found to be mainly dependent on a seawater/produced brine mixing ratio. Additionally, it was found that scaling did not occur in supersaturated mixtures of seawater, aquifer water and produced brine, which indicated that there is a critical SI for the scaling onset. The zeta potential for different formation rocks was determined for sweater, aquifer and produced brine. It was nearly zero when using only seawater. One of the major findings of this study is that the presence of sulfate ions caused clay particles to migrate even in high total dissolved solid (TDS) seawater of nearly 55,000 ppm.
Leveraging Technology Infrastructure and Experience to Enable Upstream Asset Optimization
Authors: Killian Keith E. , Jones Chris G. , Wiemers Suzan , Dubose Larry W.
Published: May 2012

Applying digital technology in the upstream introduces new equipment and applications that have the potential to transform asset management and optimization processes. Technology selection, delivery, sustainment and most importantly, business integration are key factors in making effective digital technology investments and realizing their full value. Leveraging the significant experience and synergies in ExxonMobil's* Information Technology organization and downstream has been recognized as an opportunity in the upstream to facilitate quicker technology deployment and effective, efficient sustainment. Aligning with business priorities, decisions on digital technology enablers are linked with relevant upstream best practices to facilitate integration with asset management work processes.

This paper will focus on ExxonMobil's approach with leveraging our corporate infrastructure and experience to deliver targeted upstream capabilities related to facilities, process and equipment surveillance and optimization, as well as how it enables further technology applications in advanced analytics and advanced process control.
A Unified Approach to Well Integrity Evaluation Led to Better Decision Making for Workovers in Mature Wells in the Waddell Ranch, West Texas
Authors: Babaniyazov A.. , Clayton R.. , Sykes-Bookhammer D.. , Walker R.. , Amezcua J..
Published: May 2012

The often referenced Norwegian standard D-0101 describes well integrity as the "application of technical, operational and organizational solutions to reduce the risk of uncontrolled release of formation fluids throughout the life cycle of a well". Well integrity can therefore be considered in terms of the structural soundness of the well, its casing, cement and wellhead; and how it reduces the risk of the uncontrolled flow of formation fluids to other formations or surface.

Well integrity is a critical issue when working over and recompleting mature wells. This paper describes common integrity issues and develops a workflow for managing well integrity information during the design, execution, and evaluation of workover operations.

It was found that no one measurement can give a complete well integrity analysis; instead a unified systematic approach considering a variety of measurements will lead to successful, economical, and well executed workovers.

There is a great deal of value in obtaining certainty about the status of a wellbore from a clear logging and testing regime. The type of logging package will depend on the economics of the recompletion campaign, but the cost of logging operations pales in comparison to a lost hydraulic fracture or series of expensive squeezes.

The evaluation and quantification of workover rates, reserves and economics in this field are not within the scope of this paper, and will not be addressed here.
Design Considerations for Isolating Gas-Hydrate-Bearing Zones in Deepwater Environments
Authors: PKS Sairam , Patil Rahul , Patil Sandip
Published: May 2012

Gas hydrates are known to occur in deepwater environments (low-temperature and high-pressure) at various locations across the globe. When they occur close to the sea bed, hydrates present challenges to drilling, completing, and producing in deepwater applications. Additionally, many operators now consider these as a potential resource when they occur deeper within the earth, and there is increased focus on feasibly producing methane from gas hydrates. Safety, environmental impact, and economic viability are the foremost challenges faced by the upstream oil and gas community to unleash the potential that these unconventional reserves hold for the future.

Isolating the gas-hydrate-bearing zones by means of effective annular wellbore sealants is the prime factor that will contribute to the success of gas-hydrate campaigns. This paper addresses the current zonal isolation challenges likely to be encountered from the time drilling operation is completed until the plug and abandonment process is finished. With the considered lifecycle, a sealant system selection criteria based on commercially available technologies is proposed. While industry research on this front continues to progress, a holistic approach to designing a zonal isolation program to address the foreseeable challenges of unconsolidated formations, drilling-fluid removal in washouts, annular-sealant placement, battling lost circulation, prevention of hydrate destabilization, formation-fluid influx during the setting process, achieving good mechanical properties at low temperatures, and maintaining long-term sealing integrity throughout the life of the well is discussed and evaluated.

The design approach involves (1) preliminary engineering sensitivity analysis to judge the effect of dominant parameters on sealant system design, (2) selection of commercially available, fit-for-purpose materials and laboratory testing, and (3) validation by means of confirmatory analyses. The approach presented is an incremental effort to help operators and industry researchers increase the productivity of gas-hydrate-bearing wells.
Flow Assurance In Oil Systems: On the Role And Impact Of Naphthenic Acids
Authors: Shepherd Andrew G. , Dijk Menno van , Koot Wouter , Dubey Sheila , Poteau Sandrine , Zabaras George , Grutters Mark
Published: May 2012

This paper presents an overview of the different flow assurance issues associated with naphthenic acids. In field development projects a good understanding of naphthenic acid phase behavior is essential to avoid unplanned plant changes and deferment. Good data on naphthenic acid content and speciation is obtained by using a representative sample. Basic measurements (e.g. TAN) are not sufficient to obtain a detailed understanding of the flow assurance issues regarding a particular crude oil. Infrared spectroscopy and mass spectrometry, high and low resolution, are the preferred tools for analysis of crude oils. The target naphthenic acid species, e.g. ARN or fatty acids will dictate the best suited method selected for analysis. Geochemical analysis of crude oils has helped to highlight some common features which can be used for prediction purposes. For bound soap scale-forming crude oils, a large amount of complexed acids result in emulsions which are difficult to break. Chemical treatments are needed and these should be identified early in the project stages. For soap scale-forming crude oils chemical treatment requires in depth analysis of topsides equipment and impact on existing chemical portfolio. Surveillance of soap scale-forming crude oils is possible using readily available equipment. For soap emulsion-forming crude oils, paraffin precipitation adds to the stability of the emulsion formed. Chemical treatment and heat is required for best results. Use of stock tank sample properties can be used for predictions regarding the type of naphthenic acid issue to be expected for particular crude oil sets.
Utilizing Production Logging in a Complex Completion to Enhance Productivity through Comprehensive Production Profiling, Workover Planning, and Recompletion
Authors: Gupta Shilpi , Sinha Ravi , Kumar Ajit , Pandey Arun , Ogra Konark , Verma Vibhor , Bisht P.. , Hinge P. P.
Published: May 2012

Production logging (PL) has long been in use in the industry for evaluating the well performance for making strategic decisions. However, understanding the production profiles is challenging in complicated flow regimes and complex wellbore completions. To increase productivity in underperforming sick wells, electrical submersible pumps (ESPs) are generally effective options if planned and installed judiciously. This unique case study validates the application of production logging in planning and executing workover operations and by diagnosing the issues for suboptimal production performance of an ESP completed well.

Located in XYZ field of Mumbai offshore in India, Well G has been in production since October 2006, predominantly producing at the rate of 900 barrels of oil per day (BOPD) with 10% water cut (WC). After producing for 2 years, well production declined significantly to 600 BOPD. PL data were used efficiently to increase productivity at three different stages during the life of the well. In the first stage, PL played a key role in mapping the zonal production profile. On the basis of these data, an acid job was suggested, which increased production by 300 BOPD. In the second stage, when the production rate again declined to 600 BOPD within a year, PL played a key role in defining perforation and re-perforation strategy by identifying the silent zones and helping to plan ESP installation when the well was incapable of lifting fluids to surface. This led to an increase of only 50 BOPD as compared to the expected increase of 600 BOPD. During the third stage, PL combined with a Y-tool was instrumental in diagnosing a mismatch between ESP design capacity and reduced reservoir deliverability, which was the key reason for the unexpected underproduction. On the basis of the diagnosis, an acid job was suggested to increase well deliverability. Following the acid job, production increased by almost 75% to 1034 BOPD without changing and damaging the ESP.

This case study is of interest to plan workover operations and to diagnose production problems using PL to optimize production in ESP completed wells with changing reservoir productivity.
Semi-Analytical Production Simulation of Complex Hydraulic Fracture Networks
Authors: Zhou Wentao , Banerjee Raj , Poe Bobby , Spath Jeff , Thambynayagam Michael
Published: May 2012

The application of horizontal well drilling and multi-stage fracturing has become a norm in the industry to develop unconventional resources from ultra-tight formations. A complex fracture network generated in the presence of stress isotropy and pre-existing natural fractures immensely extends reservoir contact and improves hydrocarbon production.

A semi-analytical method is presented in this paper to simulate the production from such complex fracture network. This method combines an analytical reservoir solution with a numerical solution on discretized fracture panels. The mathematics are briefly introduced. A number of case studies are presented, from a simple planar fracture to a real field example from the Barnett shale. Production behaviour and the key flow regimes are discussed.

With its simplicity, yet capturing the physics of the transient production performance, this approach provides an accessible tool for people from multiple disciplines in unconventional resource development to rapidly evaluate treated-well productivity and stimulation effectiveness.
Successful Implementation of Abrasive Perforation in Highly Deviated HP/HT Gas Well
Authors: Al-Atwi Mohammed A. , Al-Driweesh Saad M. , Al-Sagr Abdulaziz M. , Garzon Francisco O. , Al-Mulhim Abdallah A. , Kharrat Wassim , Stuker John , Keong Azwan Hadi
Published: May 2012

This paper illustrates a specific perforation technique using Coiled Tubing with an abrasive jetting tool in a highly deviated HP/HT gas well suffering severe drilling formation damage and describes how this technique bypassed the damage and increased the efficiency of acid stimulation, allowing the well to flow as expected.

Occasionally, while drilling carbonate (Khuff) gas wells in Saudi Arabia fluid losses encountered are which often leads to stuck drill pipe. Hence, a specific mud system designed with loss circulating materials (LCM) including calcium carbonate chips, graphite, and fibers is used to stop losses and reduce the risk of stuck pipe. However, the design side of this mud system creates a high near wellbore damage with very low acid solubility.

The abrasive jetting tool was selected as the perforating method because slots cut with sand slurry generate clear passage across the formation bypassing any formation damage. The slots through the casing, cement and formation were created by pumping nitrified sand slurry. Nitrogen was used for the first time in Khuff gas wells along with an orienting tool in order to increase the slot cutting efficiency and obtain deeper penetration to bypass the formation damage and allowing the acid to reach the virgin reservoir. Real-time depth correlation and differential pressure measured across the abrasive jetting nozzles were also used for the first time.

In contrast to wells drilled with the same type drilling mud but perforated with different methods, this well showed a noticeable increase in wellhead pressure during the abrasive slotting procedure. The follow up acid stimulation performed at average pump rates and pressures for a non-damaged Khuff-C gas wells.

Slot cutting design and execution, acid stimulation treatment, and well performance will be discussed to evaluate the abrasive perforation and demonstrate the advantages of generating clean and deep tunnels.
Starting up Mega-Projects, Experiences with the Start-Up of Pearl GTL
Authors: Cornelisse Roel , Gort Richard , Westerink Peter
Published: May 2012

Pearl GTL is a unique world scale Gas-To-Liquids (GTL) Complex that integrates production from two offshore platforms to products that can be sold directly into the energy, oil products and chemicals markets. It is one of the biggest and most complex mega projects that has been implemented in the Energy industry to date and with it, the partnership of QP and Shell has taken a bold step: the success of Pearl GTL is fostered in many ways in development and integration of right leadership across all parties culminating in a Flawless Startup followed by Flawless Manufacturing.

This paper will look at how Shell has orchestrated the development of its leaders in the journey of Pearl GTL and provided the necessary continuity across different stages of the Project design and implementation to capitalize in a structured manner on thousands of lessons learnt from all parties involved in the 40 year journey from Gas-to-Liquids Research to Revenue.
Pearl GTL - Achieving a World Class Safety Performance
Authors: Munster Robert J. , Bralee Abigail V.
Published: May 2012

This paper will contain details of the following aspects of Qatar Shell GTL limited's implementation of leadership safety management.

The case for change: a culture of Leadership Safety

The continuing incidence of safety accidents in the construction and projects industry has driven the recognition that safety management requires a different approach from focusing solely on occupational safety and implementation of an HSSE Management System (HSSE MS).

Leadership role and journey

The management at Pearl GTL committed to emabarking on a leadership safety journey. Managers needed training, coaching and ongoing support to grow as safety leaders and support the development of the safety culture at Pearl GTL. The attributes of a good safety leader have been identified through personal experiences and practiced within a framework of five themes.

Five leadership safety themes

The five themes identified to frame and focus the developing Pearl GTL safety culture are: Worker's Welfare, Training, Life Critical Activities, Communications and Leadership. Activities were undertaken in each of these themes to engage the workforce and build the desired safety culture. This paper will describe the activities in each of these themes.

Celebrating Success

Recognition of good safety performance, rather than focusing on what was being done wrong, was a tool successfully used by Shell management during site visits. Recognition, often in the form of a telephone card, along with a request to call home and let the family know he was safe and recognised for doing a good job, drove a culture of compliance and intervention rather than a culture of perceived blame. Celebration of individual, team and site-wide safety performance was strongly encouraged to motivate and energise the workforce and to thank them for their contribution to Pearl GLT successes. Pearl GTL Safety Days and celebrations will be described.
Innovative Engineering Makes Maureen Development a Reality
Authors: Nichols J. H. , Westby K. A.
Published: May 2012

Phillips Petroleum is again on its path to pursuing innovative technology in the field of North Sea development that will stand for years to come. In cooperation with its partners in the Maureen Field Development Project, new and unique engineering concepts in four areas are being used: Pre-drilling of wells through a seabed template for subsequent tie-back to a drilling and production platform.A Tecnomare Steel Gravity platform (TSG) with a triangular base structure composed of three cylindrical tanks for ballast and oil storage inter-connected by a tubular framework.A Brown and Root designed integrated deck called HIDECK which is built, fully equipped and partially precommissioned, then mated with the TSG prior to tow-out.An Articulated Loading Column (ALC) with a concrete body for the Single Point Mooring terminal for offshore tanker loading.

All four concepts are new for the North Sea and these elements enabled the marginal Maureen Field to become economically viable during the feasibility stage.

The Maureen Field in Block 16/29a, which is located approximately 160 miles north east of Aberdeen in 314 feet of water, is being developed by a six member gruop led by Phillips Petroleum who acts as operator. The other coventurers are Petrofina, AGIP, Century Power & Light, Ultramar and British Electric Traction. The field was discovered in January 1973 when the bit penetrated the oil bearing Paleocene Sandstone. Three additional appraisal wells were subsequently drilled to prove that Maureen was a commercial prospect. Current development plans call for 12 Paleocene producers and 7 water injectors. Refer to Fig. 1. To date 7 wells including the exploratory wells have been drilled on the structure.
Deepwater Platforms Problem Areas
Authors: Fjeld Svein , Flogeland Svein
Published: May 2012

The present paper gives a broad outline of the problems encountered in the planning of platforms for water depth more than 200-250 m. The paper does not focus specific theoretical sophistications but accentuates main problems related to technical and economical feasibility for design, construction and operation.
On-Shore Commissioning of Power Plant
Authors: Evans Albert R.
Published: May 2012

To carry out commissioning on dual fuel turbine driven generation power plant and electrical distribution equipment at the fabrication yard prior to installation in the UK sector of the North Sea.

To achieve this objective it was decided in the early stage of design to install the main generators, switchgear and all necessary controls for the main power distribution in one Module.

POWER MODULE LAYOUT

The module was divided by a mezzanine floor – on the lower level was installed the five main dual fuel turbine driven alternator units, with their associated control equipment.

On the mezzanine floor the high and low voltage switchgear was installed, along with the main transformers, synchronising panel and battery charger and batteries for the switchgear tripping and closing circuits.

For layout see Appendix 11.2

EQUIPMENT RATINGS

Main Turbine/Generators

The main turbine/generator units consisted of five Ruston TB:5000 turbines, with GEC Ltd alternators rated at 3.2 MW at 6.6 KV, 60 HZ, 0.8 pf.

High Voltage Switchgear/MCC

The High Voltage Switchgear and Motor Control Centre consisted of one complete unit, with the switchgear section located in the centre and the motor control centres to the right and left.
The Development of Articulated Buoyant Column Systems as an Aid to Economic Offshore Production
Authors: Smith John R. , Taylor Reginald S.
Published: May 2012

Floating or compliant platform systems are beginning to feature more strongly in proposed development scenarios, particularly in relation to economic production from both deeper waters and more complex or low reserve fields. This paper examines the applicability, function and performance of articulating buoyant column systems in such roles, as determined from a comprehensive research and development programme undertaken by Taylor Woodrow over the past three years.

The scope of the programme, covering hydrodynamic, material and structural studies, interfacing with production technology and construction and economic assessments is described. Particular emphasis is placed upon the evaluation of the complex interaction between compliant structures and the environment. It is concluded that articulated columns can provide cost effective alternative production systems over a range of applications, with functional and technical benefits.
Color stability and fluorescence of different orthodontic esthetic archwires
Authors: da Silva Dayanne Lopes , Mattos Claudia Trindade , de Araújo Marcus Vinicius Almeida , de Oliveira Ruellas Antônio Carlos
Published: May 2012

Objective:

To evaluate the color stability of six esthetic archwires at different time periods and their fluorescence.

Materials and Methods:

Samples were evaluated after 7, 14, and 21 days of immersion in staining solution. Color measurements were performed by means of a spectrophotometer according to the Commission Internationale de I'Eclairage L*a*b* system, and color changes (ΔE*) and National Bureau of Standards units were computed. The fluorescence of as-received samples was evaluated by two observers and compared with that of a bovine central incisor. Statistical differences were investigated using analysis of variance and Tukey's post hoc test.

Results:

All brands showed statistically significant color change after 21 days (ΔE* from 1.88 to 12.06). The Optis archwire (fiber-reinforced composite) presented the highest color alteration, although staining was observed only near its ends. The Trianeiro archwire (coated nickel-titanium) and the Ortho Organizers archwire (coated stainless steel) presented with less color change. The Optis archwire was the only one that presented with fluorescence similar to that of bovine teeth.

Conclusions:

All esthetic archwires assessed showed clinically noticeable color change after 21 days in staining solution. The optical properties of currently available esthetic archwires may not yet be ideal.
My Way or the Highway
Authors: Zeller Thomas
Published: May 2012

Roads matter. They define spaces, spur economic development, provide
ways of seeing cities and countryside, and enable generally faster forms of
moving around. While the history of mobility and transportation has paid lots
of attention to automobiles, trains, and airplanes, fewer scholarly accounts
of streets, roads, and highways exist. For one, roads, unlike cars, almost
never become individually owned objects of personal consumption. While
some iconic highways such as the myth-laden “Route 66” in the U.S. exist,
the majority of roads are nameless except for combinations of letters and
numbers. As is the case with so many other everyday technologies, most
observers only notice roads when they are dysfunctional: during traffic jams,
when they contain potholes, during periods of construction and maintenance.
Building a Hybrid Highway System
Authors: Ryckewaert Michael
Published: May 2012

This paper investigates the conception and construction of the Belgian highway network since 1945. It focuses on the formative decades of the 1950s and 1960s, when the network was designed and an important financing mechanism established (the 1955 Road Fund). A distinguishing characteristic in the construction of the network is the use of highways as a vector of urbanization for economic development purposes. Combining long-distance traffic with local access to adjoining services, these highways fulfill a twofold role defined at the conception of the network in 1951. Incorporating ring roads, expressways, regional highways, and a high density of exits into a transnational system, the Belgian network is a "hybrid" highway system.
How Were Motorways Specified? A Comment on the Special Section on Roads
Authors: Lay Maxwell Gordon
Published: May 2012

A motorway is universally defined as a road specifically provided for
motor traffic, with dual carriageways separating oncoming traffic, with
all intersections grade-separated, and with no access from abutting
properties.1 However, these three papers on motorway history will suggest
that this definition is not nearly as simple and straightforward as we might
previously have assumed. The papers are each significant contributions
to our understanding of European motorway development and usefully
present the planning and development of motorways from very different
perspectives.
Cycling
Authors: Cox Peter
Published: May 2012

The mechanized mobility practices that came to dominate road use in the twentieth century—using cars, motorbikes, and bicycles—have been notable for the concurrent development of accompanying print literatures in the form of magazines and newspapers. The developmental history of each mode can be told through a number of distinct lenses, each revealing a part of the story of the mobility technology in use. In the context of a renaissance in cycling, there is an emergence of a new style of bicycle magazine that breaks the mould of previous journals.
Community structures of endoparasitic helminths of Channa punctatus from a fresh water river and a polluted lagoon of Bangladesh
Authors: Ghani Md. Osman , Bhuiyan Aminul Islam
Published: May 2012

Community structures of the parasites of Channa punctatus collected from fresh water Ichamoti river (IR) and a polluted sewerage treatment lagoon (SL) near Dhaka city were determined. Out of the total 104 C. punctatus fish observed, 78.85% were parasitized by at least one species of helminth endoparasites. Twelve metazoan endoparasite (viz. six trematodes, one cestode, three nematodes and two acantho-cephalans) were recorded. Neopecoelina saharanpuriensis, Pallisentis nandai, P. ophiocephali, Ascaridia sp. were common in both sites. Euclinostomum heterostomum, an unidentified digenean, Genarchopsis ozakii, Gangesia bengalensis, Buckleynema channi were recorded from IR and Genarchopsis bangladensis, Phyllodistomum chauhani, Camallanus intestinalus from the SL fishes. Trematode was the most prevalent group and had 63.46% and 53.85% prevalence in IR and SL sample fishes, respectively. Among the parasites of IR sample, only E. heterostomum was accounted as secondary and others fall in the satellite species category; no central species accounted in the sample. In case of SL sample, no parasite species found central, Pallisentis spp. could be considered secondary and others as satellite species. A significant positive correlation was observed between the standard length of the host, and the abundance and prevalence found only for Pallisentis spp. in SL fishes, and between the standard length and the abundance of the Ascaridia sp. in IR fishes. The larger hosts were more infected than the smaller hosts. Parasites of the fish of both sites showed typical over-dispersed distribution pattern in both the sites. No parasite showed random or uniform distribution in both the sample fishes. Parasite species richness index was lower in SL sample. Prevalence and intensity were higher in both sexes in SL sample than those of in IR sample.DOI: http://dx.doi.org/10.3329/bjz.v39i2.10584 Bangladesh J. Zool. 39(2): 173-185, 2011
Peroxide-Dependent Analyte Conversion by the Heme Prosthetic Group, the Heme Peptide “Microperoxidase-11” and Cytochrome c on Chitosan Capped Gold Nanoparticles Modified Electrodes
Authors: Yarman Aysu , Neumann Bettina , Bosserdt Maria , Gajovic-Eichelmann Nenad , Scheller Frieder W.
Published: May 2012

In view of the role ascribed to the peroxidatic activity of degradation products of cytochrome c (cyt c) in the processes of apoptosis, we investigate the catalytic potential of heme and of the cyt c derived heme peptide MP-11 to catalyse the cathodic reduction of hydrogen peroxide and to oxidize aromatic compounds. In order to check whether cyt c has an enzymatic activity in the native state where the protein matrix should suppress the inherent peroxidatic activity of its heme prosthetic group, we applied a biocompatible immobilization matrix and very low concentrations of the co-substrate H2O2. The biocatalysts were entrapped on the surface of a glassy carbon electrode in a biocompatible chitosan layer which contained gold nanoparticles. The electrochemical signal for the peroxide reduction is generated by the redox conversion of the heme group, whilst a reaction product of the substrate oxidation is cathodically reduced in the substrate indication. The catalytic efficiency of microperoxidase-11 is sufficient for sensors indicating HRP substrates, e.g., p-aminophenol, paracetamol and catechol, but also the hydroxylation of aniline and dehalogenation of 4-fluoroaniline. The lower limit of detection for p-aminophenol is comparable to previously published papers with different enzyme systems. The peroxidatic activity of cyt c immobilized in the chitosan layer for catechol was found to be below 1 per mill and for p-aminophenol about 3% as compared with that of heme or MP-11.
On Chirality of the Vorticity of the Universe
Authors: Palle Davor
Published: May 2012

The presence of dark energy in the Universe challenges the Einstein’s theory of gravity at cosmic scales. It motivates the inclusion of rotational degrees of freedom in the Einstein–Cartan gravity, representing the minimal and the most natural extension of the General Relativity. One can, consequently, expect the violation of the cosmic isotropy by the rotating Universe. We study chirality of the vorticity of the Universe within the Einstein–Cartan cosmology. The role of the spin of fermion species during the evolution of the Universe is studied by averaged spin densities and Einstein–Cartan equations. It is shown that spin density of the light Majorana neutrinos acts as a seed for vorticity at early stages of the evolution of the Universe. Its chirality can be evaluated in the vicinity of the spacelike infinity. It turns out that vorticity of the Universe has right-handed chirality.
In Vitro Inhibition of Histamine Release Behavior of Cetirizine Intercalated into Zn/Al- and Mg/Al-Layered Double Hydroxides
Authors: Hussein-Al-Ali Samer Hasan , Al-Qubaisi Mothanna , Hussein Mohd Zobir , Ismail Maznah , Zainal Zulkarnain , Hakim Muhammad Nazrul
Published: May 2012

The intercalation of cetirizine into two types of layered double hydroxides, Zn/Al and Mg/Al, has been investigated by the ion exchange method to form CTZAN and CTMAN nanocomposites, respectively. The basal spacing of the nanocomposites were expanded to 31.9 Å for CTZAN and 31.2 Å for CTMAN, suggesting that cetirizine anion was intercalated into Layered double hydroxides (LDHs) and arranged in a tilted bilayer fashion. A Fourier transform infrared spectroscopy (FTIR) study supported the formation of both the nanocomposites, and the intercalated cetirizine is thermally more stable than its counterpart in free state. The loading of cetirizine in the nanocomposite was estimated to be about 57.2% for CTZAN and 60.7% CTMAN. The cetirizine release from the nanocomposites show sustained release manner and the release rate of cetirizine from CTZAN and CTMAN nanocomposites at pH 7.4 is remarkably lower than that at pH 4.8, presumably due to the different release mechanism. The inhibition of histamine release from RBL2H3 cells by the free cetirizine is higher than the intercalated cetirizine both in CTZAN and CTMAN nanocomposites. The viability in human Chang liver cells at 1000 μg/mL for CTZAN and CTMAN nanocomposites are 74.5 and 91.9%, respectively.
Synthesis of a 2,2'-Bipyridyl Functionalized Oligovinylene-Phenylene Using Heck and Horner-Wadsworth-Emmons Reactions and X-ray Crystal Structure of E-(4-(4-Bromostyryl)phenyl)(methyl)sulfane
Authors: Karácsony Orsolya , Deschamps Jeffrey R. , Trammell Scott A. , Nita Rafaela , Knight D. Andrew
Published: May 2012

The synthesis of a new 2,2'-bipyridyl functionalized oligovinylenephenylene (OVP-5) containing a methyl protected thiol using Heck coupling and the Horner-Wadsworth-Emmons reaction and is described. A key step involving a diisopropylcarbodiimide promoted dehydration of a stable b-hydroxyphosphonate intermediate was identified. The structure of precursor E-(4-(4-bromostyryl)phenyl)(methyl)sulfane (1) was determined using X-ray crystallography.
Europeanization of the World or Globalization of Europe?
Authors: Bentley Jerry
Published: May 2012

Building on his long career as a distinguished historian of early modern Europe, John Miles Headley has recently turned his gaze to the influence of Europe in the larger world. In The Europeanization of the World, Headley makes an insistent case for the uniqueness of European values—particularly human rights and democracy—and argues that these values are Europe’s most precious gifts to the larger world. Without seeking to diminish the remarkable intellectual and cultural achievements of European peoples, this presentation will suggest a more nuanced view of relations between Europe and the larger world. Human rights and democracy mean different things to different peoples in different contexts at different times, and there have in fact been numerous expressions of both in societies beyond Europe. Furthermore, European theorists of human rights and democracy drew influence from societies beyond Europe. To the extent that the Europeanization of the world is a persuasive idea, it is possible only because of a prior globalization of Europe.
Enabling Communication in Emergency Response Environments
Authors: Aldunate Roberto G. , Schmidt Klaus Nicholas , Herrera Oriel
Published: May 2012

Effective communication among first responders during response to natural and human-made large-scale catastrophes has increased tremendously during the last decade. However, most efforts to achieve a higher degree of effectiveness in communication lack synergy between the environment and the technology involved to support first responders operations. This article presents a natural and intuitive interface to support Stigmergy; or communication through the environment, based on intuitively marking and retrieving information from the environment with a pointer. A prototype of the system was built and tested in the field, however the pointing activity revealed challenges regarding accuracy due to limitations of the sensors used. The results obtained from these field tests were the basis for this research effort and will have the potential to enable communication through the environment for first responders operating in highly dynamical and inhospitable disaster relief environments.
Synthesis and antifungal properties of papulacandin derivatives
Authors: van der Kaaden Marjolein , Breukink Eefjan , Pieters Roland J
Published: May 2012

Derivatives of an antifungal agent that targets the β-(1,3)-D-glucan synthase, papulacandin D, were synthesized and tested for activity. The papulacandin D structure contains a challenging benzannulated spiroketal unit, which is introduced in a palladium-catalyzed cross-coupling reaction of a glycal silanolate and an aryl iodide followed by an oxidative spiroketalization. Four different variants were made, differing in the nature of the acyl side chain with respect to the length, and in the number and stereochemistry of the double bonds. Moderate biological activity was observed for the derivatives with a side chain based on palmitic acid and linoleic acid.
Characterisation of novel strains of multiply antibiotic-resistant Salmonella recovered from poultry in Southern Senegal
Authors: Dione Michel M , Geerts Stanny , Antonio Martin
Published: May 2012

Introduction: Non-typhoidal Salmonella (NTS) contamination in poultry and poultry products is a major cause of food-borne disease in humans. This study presents the molecular epidemiology of NTS isolated from poultry in Senegal. Methodology: A total of 261 NTS recovered from broiler farms, chicken carcasses and street vendors were characterized using random amplification of polymorphic DNA (RAPD) and multilocus sequence typing (MLST) techniques. Results: We observed 20 distinct RAPD profiles corresponding to 18 different serotypes. Strains from each of these 20 groups were further analysed using MLST. Consequently, 12 new MLST alleles and 17 new sequence types were discovered. Three sequence types (S. Kentucky ST198, S. Agona ST13 and S. Istanbul ST33) have previously been described in Senegal and other countries, suggesting that these clones are geographically widely distributed and are circulating in a wide range of hosts. Nine clones showed multi-resistance to the most commonly used antibiotics in both humans and animals. However, a novel multi-resistant clone of S. Kentucky ST832 was found. Conclusion: This study gives new insights into the genetic diversity of NTS in Senegal. Molecular tools remain essential to improve our understanding of the epidemiology of NTS by tracking the sources of infection and/or contamination.
Plasmodium falciparum and intestinal parasitic co-infections in HIV-infected patients in Benin City, Edo State, Nigeria
Authors: Akinbo Frederick Olusegun , Okaka Christopher Ehis , Omoregie Richard
Published: May 2012

Introduction: Human co-infection with Plasmodium falciparum and helminthes is ubiquitous throughout Africa. This study aimed to determine the co-infections of Plasmodium falciparum infection in HIV and intestinal parasitic infections, and their immunological distribution, in Benin City, Nigeria. Methodology: A total of 2,000 stool specimens from HIV-positive patients and 500 controls (HIV-negative individuals) were examined for ova, cysts, or parasites using standard procedures. In addition, patients' blood samples were analyzed for CD4 counts by flow cytometry and examined for Plasmodium falciparum by microscopy. Results: The prevalence of single parasitic infection among HIV patients was 18.1% in males and 16.9% among females with no significant difference (p = 0.536) while gender was a risk factor in multiple parasitic infections (male versus female: 4.2% and 1.8% OR = 2.384; 95% CI = 1.371, 4.147) (p = 0.0025). Increasing age was not associated with increased risk of both single and multiple parasitic infections (p = 0.083; p = 0.248). CD4 + T cell count less than 200 cells/µl was a risk factor for acquiring single and multiple parasitic infections among HIV patients (OR = 5.565; 95% CI = 4.136, 7.486; p = 0.0001; OR = 4.283; 95% CI = 2.424, 7.566; p = 0.0001). The most common co-infection observed was between Plasmodium falciparum and Ascaris lumbricoides 43% (10) among HIV patients. Conclusion: This study provides evidence of co-infections between Plasmodium falciparum and intestinal parasites. Diagnosis of parasitic infections among HIV patients is advocated as this will enhance better management of HIV-infected patients.
Treatment with Biologic Agents Improves the Prognosis of Patients with Rheumatoid Arthritis and Amyloidosis
Authors: KURODA TAKESHI , TANABE NAOHITO , KOBAYASHI DAISUKE , SATO HIROE , WADA YOKO , MURAKAMI SHUICHI , SAEKI TAKAKO , NAKANO MASAAKI , NARITA ICHIEI
Published: May 2012

Objective.

Reactive amyloid A (AA) amyloidosis is a serious and life-threatening systemic complication of rheumatoid arthritis (RA). We evaluated the safety of therapy with anti-tumor necrosis factor and anti-interleukin 6 biologic agents in RA patients with reactive AA amyloidosis, together with prognosis and hemodialysis (HD)-free survival, in comparison with patients with AA amyloidosis without such therapy.

Methods.

One hundred thirty-three patients with an established diagnosis of reactive AA amyloidosis participated in the study. Clinical data were assessed from patient records at the time of amyloid detection and administration of biologics. Survival was calculated from the date when amyloid was first demonstrated histologically or the date when biologic therapy was started until the time of death or to the end of 2010 for surviving patients. Patients who had started HD were selected for inclusion only after the presence of amyloid was demonstrated.

Results.

Fifty-three patients were treated with biologic agents (biologic group) and 80 were not (nonbiologic group). Survival rate was significantly higher in the biologic group than in the nonbiologic group. Nine patients in the biologics group and 33 in the nonbiologic group started HD. Biologic therapy had a tendency for reduced risk of initiation of HD without any statistical significance.

Conclusion.

Patients with amyloidosis have a higher mortality rate, but the use of biologic agents can reduce risk of death. The use of biologics may not significantly influence the HD-free survival rate.
Regards de lycéens sur les rôles masculins et féminins à Tijuana (Basse-Californie, Mexique)
Authors: Brugeilles Carole
Published: May 2012

Résumé Le développement du recours à une perspective de genre pour expliquer les comportements sociodémographiques a donné un élan à l’analyse de la construction sociale du masculin et du féminin dans une approche relationnelle. Cependant malgré leur multiplication, les recherches sur les identités masculines et sur le regard des hommes sur les identités féminines semblent encore en retrait. Cette recherche exploratoire souhaite contribuer à cette connaissance en s’intéressant plus précisément aux représentations des rôles sexués d’adolescents lycéens à Tijuana, en Basse-Californie, au Mexique. Elle s’appuie sur l’analyse d’une enquête auprès de 1 057 lycéens. La pluralité des représentations des identités sexuées est évidente et les positions nettement progressistes ne dominent pas. La majorité des adolescents ne sont pas clairement dégagés de stéréotypes relatifs aux capacités intellectuelles et semblent adhérer à une « essentialisation » des différences, dont découlent « naturellement » des rôles sexués spécifiques. L’attachement à l’identité masculine classique est particulièrement marqué. La recherche des facteurs qui influencent les opinions souligne la complexité des processus de changements et l’école semble être un levier particulièrement important.
La migration des jeunes indiens mexicains aux États-Unis : enjeux, défis et nouvelles subjectivités
Authors: Moreschi Alejandra Aquino
Published: May 2012

Résumé Vers la fin des années 1980, la migration internationale s’est imposée dans la vie quotidienne des Zapotèques de la Sierra Norte de Oaxaca, au sud du Mexique. Les communautés indiennes ont alors dû faire face à la dépopulation de leurs villages et à la transformation de leur économie paysanne traditionnelle par l’injection d’argent venu des États-Unis. Autre défi de taille : le changement des perspectives d’avenir et des projets de vie de la jeune génération. Cet article montre qu’aujourd’hui la migration des jeunes indiens ne répond pas seulement à une logique économique, mais traduit également l’existence de « besoins subjectifs » liés à la recherche, tant d’un nouveau style de vie permettant la mobilité spatiale et sociale, que de modèles de relations de couple et de famille plus ouverts. Bien que subjectifs, ces nouveaux « besoins » se sont généralisés au point de constituer un important moteur de changement dans la région et un enjeu majeur à la fois pour les familles zapotèques et pour les processus en cours de recouvrement de l’autonomie politique de ces communautés.
Des diables, des prophètes et des banzis sur les scènes de Libreville : les réemplois religieux des rappeurs du Gabon
Authors: Aterianus-Owanga Alice
Published: May 2012

Résumé À partir de données de terrain recueillies auprès des rappeurs de Libreville, cet article se propose de participer au renouvellement des questionnements sur les transformations religieuses contemporaines, en décrivant les différentes significations revêtues par les symboles religieux qu’emploient ces artistes. L’analyse de ces pratiques musicales urbaines permettra d’interroger comment les nouvelles scènes musicales mettent en mouvement des éléments religieux du contexte gabonais pour les réinvestir selon des logiques politiques, sociales et identitaires singulières. Cet article propose de mettre à jour les codes et les logiques sous-tendues par la référence à la chrétienté ou par les réemplois de certains objets rituels issus des religions initiatiques traditionnelles chez ces jeunes artistes.
Les compagnies pétrolières à l'épreuve du développement : le cas du delta du Niger (Nigeria)
Authors: Pérouse de Montclos Marc-Antoine
Published: May 2012

Résumé À partir d’un cas d’étude empirique dans le delta du Niger au Nigeria, cet article vise à mettre évidence les difficultés que pose concrètement l’application d’un principe de développement qui assigne aux compagnies pétrolières une fonction non seulement économique et sociale, mais aussi politique. Les enquêtes de terrain montrent en effet que l’intermédiation des ONG ne suffit pas à suppléer aux défaillances des administrations locales, et que les initiatives de développement ne peuvent pas non plus être pensées en dehors de l’État.