bluuebunny/crossref_metadata_2025 huggingface dataset:
GIS Technology Development for Sediment Characterisation of Angolan Deepwater Soil Conditions
Authors: Hamon Michel , Enjaume pierre , Epalanga Katia , Mackenzie Brian
Published: May 2011

The first deepwater geotechnical site investigations in Angola were conducted in 1998 on the Kuito and Girassol fields. Since that date, geotechnical data have been gathered in a large number of deepwater sites to support safe and economic design of many types of subsea infrastructures (anchors, sealines, subsea foundations …). The deepwater operators in Angola (BP Angola, CABGOC, Esso Exploration Angola, Total E&P Angola) set up an expert committee to agree on how to improve understanding of seabed soil conditions and their interaction with foundation structures for the deepwater Angola. The expert committee agreed on how the factual data collected would be combined in a single database and the task devoted to Angola Deepwater Consortium (ADC) to develop a Geographic Information System (GIS) containing information on geotechnical data against a background representing high resolution bathymetry and as-built facilities in the deepwater blocks. Fugro Geoconsulting Limited was chosen to construct the database and install it on the internationally well-known ArcGIS software which has been customized for this project.

The Angolan GIS database represents an unprecedented gathering of factual data which can then be viewed, accessed and queried through a map-based user friendly interface. It helps experts for an improved region-wide understanding of soil conditions. In the early stage of future field developments, it helps making a preliminary assessment of soil data trends, seabed landscape and features and planning soil investigations.

Currently, the database contains 40 site investigation projects and represents around 1000 information points (in-situ testing and borehole) and more than 70,000 individual measurements. It has been used to support a regional-wide geological desktop study and a preliminary analysis of soil conditions in deepwater Angola.

The database is the result of exceptional cooperation between Angolan deepwater operators and a further objective is, for Sonangol, to operate and maintain this database in Angola which will provide a comprehensive, updatable and evolving repository of hard-won soils data relevant to future deepwater field developments offshore Angola.

Introduction

Background

As part of a general effort to improve oil development in deepwater offshore Angola, Angola Deepwater Consortium (ADC) was formed in 2000 by Sonangol with industrial partners Doris Engineering and Pride Foramer. ADC has performed a number of studies under the guidance of a JIP Steering Committee composed of representatives and experts of BP, CABGOC, Esso Exploration Angola and Total E&P Angola (Da Costa & al., 2005).
Developing And Using A Deepwater Predictive Soil Model To Optimize The Parque das Conchas (BC-10) FPSO Mooring Layout
Authors: Campbell Kerry J. , Newlin Jason , Gisler Evan P. , Alhayari Samy
Published: May 2011

This paper provides a methodology for optimizing a deepwater mooring layout with respect to ground conditions and gives limitations of the method. Specifically, this paper:describes development of a predictive soil model based on integration of AUV geophysical survey and geotechnical data in an area characterized by complex and discontinuous sand strata interbedded with clays;describes using the predictive model to help optimize a FPSO mooring layout to meet design criteria;presents as-installed results for the suction anchors and demonstrates reliability of the predictive soil model;describes learnings from this project; anddiscusses limitations of the methodology.

Suction-anchor installation was completed successfully and no problems were encountered with respect to soil conditions. The as-installed results thus confirmed the general reliability of the predictive soil model. Sand strata as thin as about 30 cm thick were predicted by the model and their presence was confirmed by increased pump underpressures recorded during anchor installation. The fact that the 5-m-diameter suction anchors " felt?? such thin sands was instructive. We demonstrate that, by using appropriate geophysical survey data calibrated with geotechnical information, a model of soil conditions can be developed and used as a tool to predict soil conditions away from geotechnical control points. Confidence in the predictions depends on the amount, type, spatial distribution, and quality of the data available and on the geology of the site.

This case history is useful as a model approach for optimizing mooring layout with respect to ground conditions or for other applications where shallow soil conditions are sufficiently complex and variable to affect layout of foundation elements or design. Integrated study of the geophysical/geotechnical data was concurrent with mooring system design in a collaborative effort that directly influenced design iterations. Use of the integrated and iterative approaches described here will help future project teams develop more reliable mooring or other foundation solutions faster and thereby reduce costs.

Introduction

Background. The Parque das Conchas development is located off the coast of Brazil in the Campos Basin in Block BC-10 (Figure 1). Shell is the operator of BC-10 with 50% equity share with co-venturers Petrobras (35%) and ONGC (15%). The site is on the continental slope and is characterized by hummocky topography (Figures 2 and 3a) caused by buried mass-transport deposits (MTDs). Water depths across the mooring spread range from about 1740 m to 1800 m (Figure 3a). Production facilities feature the FPSO Espirito Santo with a clustered 3x3 suction-anchor mooring system; the mooring layout is shown in Figure 3a. Mooring radius varies slightly from cluster-to-cluster and ranges between about 2500 to 2700 meters. More details and other aspects of the FPSO Espirito Santo are discussed by Howell and others (2010).
The Offshore Vital Link for Tandem Transfer of LNG
Authors: Devehat Renaud L.E.
Published: May 2011

With a number of Floating LNG Production projects now materializing to make use of the massive remote gas reserves available offshore, it is now required to overcome in a safe and reliable manner the associated technical challenges. Although FMC Technologies already opened the way to offshore receiving terminals with side-by-side Chiksan® loading arms, the cryogenic tandem offshore transfer operations required for export terminals were recognized to be, by far, the most critical link in the whole offshore LNG chain. FMC Technologies Chiksan® Articulated Tandem Offshore Loader (ATOL) now closes this gap and brings to the industry a straightforward solution relying only on field proven components and on a nearly 50 years leadership in cryogenic transfer of LNG.

There are a number of vital features any tandem LNG transfer system must be able to achieve in order to meet today's requirements for safety, performance, reliability and cost efficiency. Amongst those, the ability to operate under highly dynamic condition, the long term reliability all along the FLNG lifetime, the safety requirements like fire safety and reliable position monitoring, the low pressure loss challenge, the coexistence of sea water and cryogenic conditions, the maintainability as well as the tolerance of the system to unexpected operational events are some of the key characteristics ensured by the FMC Chiksan® ATOL based on fully field proven and sound technology and engineering practices.

Over the past few years, intensive developments at detailed engineering level for both mechanical and control system parts, advanced but realistic structural and dynamic calculation, and finally actual prototypes comprehensive testing supporting the qualification of the ATOL have placed FMC in a position to offer today the most competitive solution with the most advanced development level and based exclusively on field proven components. With the appropriate technology fully developed, FMC is ready to engage now concretely to make the upcoming FLNG projects a reality.
Application of High Resolution Zero-Offset and Walkaway VSP in Reservoir Delineation
Authors: Zhu Guang-Ming , Cao Song
Published: May 2011

To more finely delineate reservoirs and estimate more reliable oil and gas reserves, we have carried out one high-resolution zero-offset VSP(ZVSP) survey and two 2-D cross walkaway VSP (WVSP) surveys, based on available well log and 3-D surface seismic data, in L oil field. For each shot of VSP data acquisition, the depth of seismic source was selected carefully and the source was exploded with a small charge of dynamites in a single source well. Seismic signals were recorded in a denser 2.5m receiver spacing by eleven-level borehole geophones with clamping devices. The frequency bandwidth of recorded data is 8~120Hz. High resolution VSP data processing mainly consists of a first consistency processing, a subsequent estimate of absorption and attenuation coefficient Q from VSP and then the use of the Q value to increase the resolution of 3-D surface seismic data. The high-resolution-improved VSP data modify the depths of tops of three dominant reservoirs inferred from well log and add a new reservoir by a comparison of seismic events and geological layers. Finely delineating reserves by a joint use of WVSP images and the high-resolution-improved 3-D surface seismic data enhance the reliability of reservoir estimate of L oil field.

1 Introduction

L oil field is a significant oil and gas developing area. Totally 49 wells have finished drilling and 22 of which have obtained industrial oil flowing. But the oil layers in the area are thin and the oil-water relations are complex, that results in high adventure for further developing. Although 3-D surface seismic survey has been carried out in the area to emphasize geological responds of core reservoirs and improve the identification ability of thin layers by frequency increasing processing, the processed 3-D surface data are a bit suspicious. Therefore one high resolution zero-offset VSP(ZVSP) survey and two 2-D cross walkaway VSP(WVSP) surveys for a well in the area have been carried out complementarily, in order to calibrate horizons of 3-D surface data more accurately, to describe lateral variation of reservoirs in the vicinity of borehole and to enhance the reliability and accuracy of processing and interpretation of surface seismic data though a bridge between well and surface 3-D seismic data constructed by VSP.
Application of a New Wire Carcass Design for Prevention of Singing Behavior in Flexible Risers
Authors: Nielsen Karsten Gorm , Bendiksen Erik , Belfroid Stefan , Korst Harry
Published: May 2011

The flow of fluid over the inner surface of rough bore flexible pipes may create vortex induced pulsations. For gas risers these pulsations can in some cases be the source of a high amplitude tonal sound. This phenomenon is in the industry referred to as " singing risers?? Under certain circumstances these pulsations can result in large structural vibrations with potential fatigue failure of the connected topside or subsea pipe systems. Such damage has occurred in practice in a few cases, for instance on Statoil's Åsgard B platform.

The singing behaviour is dependent on the operating conditions such as product density and viscosity as well as the piping layout of the topside and subsea piping, however, the most important factor is the geometry of the corrugations. In traditional designs the carcass is made from a folded metallic strip. NKT Flexibles has developed a novel approach to carcass manufacturing originally intended for deep and ultra deepwater applications wherein the carcass is made of helically wound wires rather than a folded strip. Although the main focus for this development was to devise a carcass of superior strength compared to conventional systems, the new carcass design provides a very smooth inner surface, thus mitigating vortex formation which will reduce or eliminate the formation of flow induced pulsations.

The development of the new carcass concept is presented together with the benefits in response to the reverse end cap effect at large water depth, and the increase in collapse strength. Examples of manufacturing and testing of pipes using the new carcass design are shown.

The susceptibility to singing of the new carcass design is compared to that of a traditional carcass design. This includes the onset of the singing and the flow pressure drop. Due to the much smaller cavities in the new design, the singing tendency is shown to be significantly reduced. In particular, the expected onset velocity is 5-9 times that of a classic rough bore design with 20%-50% of the amplitude. An additional benefit of the new design is that the pressure drop for the pipe is close to that of a smooth bore pipe. Therefore, it is expected that for many applications, the new design will not lead to the generation of high amplitude tonal noise within the desired operating envelope.

Introduction

General

Un-bonded flexible pipes are used successfully throughout the world in connection with offshore oil and gas production, including floating production facilities. As the oil and gas production moves into deeper and deeper waters the flexible pipe technology becomes challenged with respect to:Collapse resistanceResistance to cope with the axial compression due to the reverse end cap effectThermal performanceHigh tension at hang off (extreme and fatigue loading).
Control System Upgrades for Tordis and Vigdis Field - A Project Case Study of Revitalising Brownfield Developments with Next Generation Subsea Controls
Authors: Frantzen Karl Herman , Kent Ian , Phillips Ray
Published: May 2011

Since the 1980s, multiplexed electro-hydraulic control systems have been successfully employed in subsea oil and gas production. With field lives extending, and the original equipment becoming more difficult to maintain, particularly because of electronic component obsolescence, it is possible by applying new generations of control system equipment to bring enhanced controls capabilities into brownfield developments.

From the inception of the Tordis/Vigdis Controls upgrade & Modification programme (TVCM), it was seen that a number of the design limitations of the legacy system could be overcome when upgrading to a modern and flexible communications system with standard comms interfaces.

There were some specific limitations of the installed system, and in addition, for the legacy system, electronic component obsolescence was becoming an increasing burden in support of continuing production.

Following the completion of the upgrade under the TVCM programme, the new system will deliver significant step-changes in the performance envelope of the overall Control and Instrumentation System, including improved reliability, a new configuration employing ‘Open’ communications protocols between topsides and subsea with the communications bandwidth available to the Tordis producer wells upgraded to 1Mbit/s.

A novel feature, and a key success factor for the project, is the use of Subsea Control Module interface adapters.

Background

The Tordis and Vigdis oil fields lie in block 34/7 in the Tampen area of the Norwegian North Sea, and came on stream in 1994 and 1997 respectively, developed with subsea installations and operating in water depths from 200m to 280m.

In addition to the main Tordis structure, the development embraces the Tordis East (1998), and Tordis South East (2001) fields.
Versatility in Answering the Challenge of Deepwater Field Developments
Authors: Bullock Jackson D. , Geertse Eduard , Landwehr Marcel
Published: May 2011

The paper will address the application of a versatile asset in the execution of a multifaceted deepwater installation project. An asset equipped such as the Borealis supporting heavylift, S-lay, J-lay and Flex-lay can allow the project to design installation scenarios which address very specific permanent equipment qualifications while promoting cost effective installation and schedule advantages.

Most deepwater projects include several permanent components which require intense engineering focus and special capabilities to facilitate installation. The complexities of the installation exposes the offshore operation to risks and opens opportunities for innovation in design and methodology of installation as mitigation measures. The combination of the thorough onshore installation engineering, the asset capabilities, and the flexibility of installation methodologies available can allow the project to take the full benefits surrounding complex issues.

The paper builds case studies in which the application of the various installation methodologies could provide significant flexibility benefits in the execution of a deepwater project. The case studies will review the technical considerations related to vessel capabilities and the challenges of several project scenarios. Focus will be direct towards advantages derived from specific operations such as:–Installation Sequence: S-lay to J-lay–Installation Sequence: J-lay to S-lay–Installation by J-lay and S-lay with pipeline structures–Complex existing infrastructure scenario–Full Field development scenario

Brief method statements and risk/opportunity reviews are provided for each case study.

The Borealis has the capabilities required to address challenges presented in the execution of a multifaceted deepwater installation project. With heavylift capabilities of over 5,000Te, including extended subsea reach, the asset is well suited for surface and subsurface lifts. The S-lay capability allows for higher production rates and economical installations over longer pipeline lengths. Capabilities in J-lay makes the vessel versatile in the installation of SCRs, ultra-deepwater pipelines significant Inline Structures/PLETs/PLEMs and subsea manifolds. The vessel will be prepared for installation of flexibles using a 500 T flexlay tower.

Introduction

Differing from shallow water field developments, deepwater field developments have specific technical challenges both in design as well as installation of the offshore infrastructure.

In recent years the boundaries of technical capabilities in design and installation techniques have expanded and field developments are moving into ever deeper water depths, further away from existing infrastructure.

Examples of existing deepwater developments are: Chevron Tahiti, Anadarko Independence Hub / Trail development, Chevron Blind Faith, Chevron Jack & St. Malo, etc. etc. Future developments could include: Hess Tubular Bells, Exxon Hadrian, Hess Pony, Anadarko Lucius, etc.
Design Considerations for Offshore Wind Turbines in US Waters - The American Way
Authors: Yu Qing , Samuelsson Lars , Tan Pao-Lin
Published: May 2011

This paper addresses unique design considerations for the support structure of an offshore wind turbine in US waters and how the Working Stress Design (WSD) approach can be applied. The Load and Resistance Factor Design (LRFD) criteria specified in IEC 61400–3 are primarily developed based on the experience from offshore wind turbines installed in European coastal areas. Due to the higher variability of the wind and wave climate in hurricane-prone areas, offshore wind turbines in US waters would not achieve the same level of safety as those in European waters if the existing IEC design criteria were applied. To address this, a set of acceptance criteria, accounting for the unique design consideration related to tropical storms, has been developed and are published in the ABS Guide for Building and Classing Offshore Wind Turbine Installations. Extensive calibrations have been carried out to verify the adequacy of design load conditions and structural design requirements of the ABS WSD-based design criteria. Metocean conditions in the US Gulf of Mexico (GoM) and East Coast were used in the calibrations to calculate the aerodynamic and hydrodynamic loads as well as the structural responses of the typical designs of offshore wind turbines.

Introduction

The US offshore oil and gas industry has extensive experience with hydrocarbon-related offshore structures installed on the US Outer Continental Shelf (OCS). A series of Recommended Practices (RP) has been published through American Petroleum Institute (API) under its Subcommittee on Offshore Structures. The main document is API RP 2A-WSD [2], which provides a comprehensive basis for the design of offshore structures subjected to wave, wind, current and earthquake loading conditions on the US OCS. What is not included in API RP 2A-WSD, however, is the definition of environmental and load conditions that can account for unique response characteristics of offshore wind turbines.

Several design and certification guidelines have been developed primarily based on the experience from offshore wind turbines installed in European coastal areas. Of these guidelines, the International Electrotechnical Commission (IEC) 61400–3 Wind turbines - Part 3: Design Requirements for Offshore Wind Turbines [12] embodies the industry's state-of-the-art knowledge for offshore wind turbines. Although a framework to define the site-specific Class S wind turbines is included in IEC 61400–1 Wind turbines - Part 1: Design Requirements [11] and further referred to by IEC 61400-3, the applicability of IEC standards to the offshore areas subject to the risk of tropical storms remains unanswered. Further validations and possible modifications are important to determine to what extent the IEC61400-3 design criteria can be adopted for the US OCS.
The Geophysics and Geology of Emerging Techniques in Subsalt Imaging
Authors: Lewis Jennifer Lyn , Blumenthal Errol
Published: May 2011

Historically, shallow well-imaged reservoirs have supported the exploration and production programs of many regions around the world. As these " easy?? fields are depleted, industry is moving to deeper and more geologically complex areas to explore. Over the past decade, many subsalt fields have been discovered and are entering the appraisal and development phases. With the transition from exploration to appraisal and development comes the need for improved and more accurate subsurface characterization. Salt, often many thousands of meters thick, such as that found in the canopies of the Gulf of Mexico and the autochthonous salt layers of offshore Brazil and Angola, present numerous challenges ranging from drilling and reservoir management to seismic imaging.

Presalt seismic data are notorious for their low frequency content, multiple contamination, and poorly constrained velocities. These limitations make characterization of key reservoir uncertainties, such as faulting, compartmentalization and overall structural geometry, an onerous undertaking at best. Recently, industry has recognized step-change improvements in subsurface imaging in deepwater subsalt settings, particularly in the Gulf of Mexico, with advances such as wide-azimuth acquisition (Fig. 1), model-based or interactive velocity analysis, and two-way depth migration algorithms (Fig. 2).
Performing Detailed Level 1 Pipeline Inspection in Deep Water with a Remotely Operated Vehicle (ROV)
Authors: Kros Hans
Published: May 2011

1. Introduction

In today's world, emphasis is being placed on the importance of inspections of the subsea assests due to recent pipeline failure events in the USA. Subsea pipelines are typically monitored by the use of intelligent pigging. However many pipe sections have limited or no piggable access. An additional method of inspection is to survey, inspect and collect data externally from the pipeline. In shallower water areas this is challenging due to visibility limitations and pipeline burial below mudline. However once extended into deepwater these limitations are no longer of issue. The pipelines are not buried, and visibility is typically quite good. With the aid of ROVs, the entire pipeline can be inspected externally by tracking the vessel and ROV along the pipeline. The data acquired is of significant value to the client as external corrosion, pipeline damage, and anode wear can be detected and monitored.

2. Regulatory Requirements

Regulatory Agencies stipulate that an inspection plan needs to exist to inspect pipelines and to report on their condition. " The OCPIS Plan recognizes that the best approach to inspecting offshore pipelines is to critically examine each line individually and develop an inspection program for each based on the present condition and risk potential of the line." (BOEMRE.gov) The regulatory agencies expect that the pipeline owners be aware of the pipeline's present conditions and its inspections needs in order for the agencies to make informed decisions regarding the pipeline's operation. (BOEMRE.gov) Pipeline owners and operators must also develop risk mitigation plans for insurance purposes. The more comprehensive the risk mitigation plan, the more confident the insurer is to lower the cost of premiums.

3. Classifications

Pipeline inspections are categorized into levels of complexity and invasiveness. Level??one inspections are categorized as visual inspection and non destructive inspections such as cathodic protection. Level??two inspections require more invasive practices and specify deburial and debris removal. This document covers level??one inspections only, particularly deepwater areas where visibility on the seabed is not a concern. Shelf and shallow water areas typically have limited visibility within the Gulf of Mexico for example.
Evaluation of Worn Tubulars from DEA-42 and Small-Scale Casing Wear Testers
Authors: Doering Abbe E.R. , Danks Daniel Robert , Mahmoud Salah E. , Scott Joe Lynn
Published: May 2011

As part of a larger project to build a new casing wear test machine, an analysis of wear mechanisms on several down-hole hardbanding/casing components has been conducted. Specimens included casing and hardbandings from a DEA-42 casing wear tester, casing and hardbandings from a new small-scale casing wear tester and a tool joint from field service.

Similar wear mechanisms including adhesion, abrasion, checking and spalling were observed on specimens from all three sources. Additionally, significant hardworked layers developed on all wear surfaces and adhesive wear was typically dominant. The study indicates that the new small-scale casing wear tester is capable of producing wear mechanisms comparable to both historical data generated by the DEA-42 test and from commercial down-hole service.

1.0 Background

A laboratory test that attempts to simulate a revenue service application must produce comparable information to the service situation. As strict as possible adherence to operating conditions is required. A second goal of the laboratory test is the simplification of operating parameters to minimize cost and time but more importantly to minimize the variability in results that are caused by random operating conditions. The same strategy is necessary when designing test equipment intended to produce similar data as an existing laboratory test. Any attempt to simulate a particular wear situation requires duplicating both wear mechanisms and relative wear rates. The wear mechanism is especially crucial because it is of utmost importance in determining the wear rates. Additionally, unless a completely independent wear database is generated with a new machine, the relative wear rates of the old and new must have some predictable correlation.

Attempts have been made in the past to understand wear on both tool joint (hardbanded and not) and casing in downhole operations. Best described several types of wear mechanisms produced in a laboratory rig that included adhesive, abrasive, ploughing and fatigue. (1, 2) The testing was conducted in a rig very similar to the current DEA-42 standard. Williamson used a different test rig that also used full sized tooljoints and casing segments to test the effects of contact pressure and found an experimental relationship between contact pressure and casing wear and used that data to develop a predictive casing wear rate model. (4) White et al also used a test rig with full size tool joints and three casing grades (K55, N-80, P110) and related casing wear to energy dissipation as a result of friction. (3)
Ibutilide for the Cardioversion of Paroxysmal Atrial Fibrillation during Radiofrequency Ablation of Supraventricular Tachycardias
Authors: Polymeropoulos Kostas , Vassilikos Vassilios P. , Mantziari Lilian , Paraskevaidis Stelios , Karamitsos Theodoros D. , Mochlas Sotirios , Parcharidis Georgios , Louridas Georgios , Styliadis Ioannis H.
Published: May 2011

Direct current electrical cardioversion (DC-ECV) is the preferred treatment for the termination of paroxysmal atrial fibrillation (AF) that occurs during radiofrequency ablation (RFA) of supraventricular tachycardias (SVT). Intravenous Ibutilide may be an alternative option in this setting. Thirty-four out of 386 patients who underwent SVT-RFA presented paroxysmal AF during the procedure and were randomized into receiving ibutilide or DC-ECV. Ibutilide infusion successfully cardioverted 16 out of 17 patients (94%) within  min. DC-ECV was successful in all patients (100%) within  min. Efficacy and total time to cardioversion did not differ between the study groups. No adverse events were observed. RFA was successfully performed in 16 patients (94%) in the ibutilide arm and in all patients (100%) in the DC-ECV arm, p = NS. In conclusion, ibutilide is a safe and effective alternative treatment for restoring sinus rhythm in cases of paroxysmal AF complicating SVT-RFA.
Catalytic oxidation of H2 on platinum: a method for in situ calibration of hygrometers
Authors: Rollins A. W. , Thornberry T. D. , Gao R.-S. , Hall B. D. , Fahey D. W.
Published: May 2011

Abstract. Standard reference samples of water vapor suitable for in situ calibration of atmospheric hygrometers are not currently widespread, leading to difficulties in unifying the calibrations of these hygrometers and potentially contributing to measurement discrepancies. We describe and evaluate a system for reliably and quantitatively converting mixtures of H2 in air to H2O on a heated platinum (Pt) surface, providing a compact, portable, adjustable source of water vapor. The technique is shown to be accurate and can be used to easily and predictably produce a wide range of water vapor concentrations (≈1 ppm−2 %) on demand. The result is a H2O standard that is suitable for in situ calibration of hygrometers, with an accuracy nearly that of the available H2 standards (≈±2 %).
Airborne measurements of aerosol scattering properties above the MABL over Bay of Bengal during W_ICARB – characteristics and spatial gradients
Authors: Sreekanth V. , Krishna Moorthy K. , Satheesh S. K. , Suresh Babu S. , Nair Vijayakumar S. , Niranjan K.
Published: May 2011

Abstract. Realizing the importance of aerosol characterization and addressing its spatio-temporal heterogeneities over Bay of Bengal (BoB), campaign mode observations of aerosol parameters were carried out using simultaneous cruise, aircraft and land-based measurements during the Winter Integrated Campaign for Aerosols gases and Radiation Budget (W_ICARB). Under this, airborne measurements of total and hemispheric backscatter coefficients were made over several regions of coastal India and eastern BoB using a three wavelength integrating nephelometer. The measurements include high resolution multi-level (ML) sorties for altitude profiles and bi-level (BL) sorties for spatial gradients within and above the Marine Atmospheric Boundary Layer (MABL) over BoB. The vertical profiles of the scattering coefficients are investigated in light of the information on the vertical structure of the atmospheric stability, which was derived from the collocated GPS (Global Positioning System) aided radiosonde ascents. In general, the altitude profiles revealed that the scattering coefficient remained steady in the convectively well-mixed regions and dropped off above the MABL. This decrease was quite rapid off the Indian mainland, while it was more gradual in the eastern BoB. Investigation on horizontal gradients revealed that the scattering coefficients over northern BoB are 3 to 4 times higher compared to that of central BoB within and above the MABL. A north-south gradient in scattering coefficients is observed over Port Blair in the eastern BoB, with values decreasing from south to north, which is attributed to the similar gradient in the surface wind speed, which can be replicated in the sea salt abundance. The gradients are parameterized using best-fit analytical functions.
3-D thermo-mechanical laboratory modeling of plate-tectonics: modeling scheme, technique and first experiments
Authors: Boutelier D. , Oncken O.
Published: May 2011

Abstract. We present an experimental apparatus for 3-D thermo-mechanical analogue modeling of plate tectonic processes such as oceanic and continental subductions, arc-continent or continental collisions. The model lithosphere, made of temperature-sensitive elasto-plastic analogue materials with strain softening, is submitted to a constant temperature gradient causing a strength reduction with depth in each layer. The surface temperature is imposed using infrared emitters, which allows maintaining an unobstructed view of the model surface and the use of a high resolution optical strain monitoring technique (Particle Imaging Velocimetry). Subduction experiments illustrate how the stress conditions on the interplate zone can be estimated using a force sensor attached to the back of the upper plate and adjusted via the density and strength of the subducting lithosphere or the lubrication of the plate boundary. The first experimental results reveal the potential of the experimental set-up to investigate the three-dimensional solid-mechanics interactions of lithospheric plates in multiple natural situations.
Telerehabilitation In South Africa – Is There A Way Forward?
Authors: Mars Maurice
Published: May 2011

South Africa, like the rest of sub-Saharan Africa, has a disproportionate burden of disease and a shortage of health professionals. Telemedicine has been identified as a possible way of overcoming part of the problem but telemedicine has not been widely adopted. In the public sector hospitals in South Africa which serve 82% of the population there are 2.5 physiotherapists and 2 occupational therapists per 100,000 people served. The extent of telerehabilitation in South Africa is unknown. A literature review of telerehabilitation found no papers from South Africa. A survey of the heads of university departments of physiotherapy, occupational therapy and speech and language pathology revealed limited knowledge of telerehabilitation. Telerehabilitation services are confined to follow-up of patients at some institutions by telephone, fax or email. There is need to raise awareness among therapists if telerehabilitation is to become a reality in South Africa.  Future actions are outlined.
VOIP for Telerehabilitation: A Risk Analysis for Privacy, Security and HIPAA Compliance: Part II
Authors: Watzlaf Valerie J.M. , Moeini Sohrab , Matusow Laura , Firouzan Patti
Published: May 2011

In a previous publication the authors developed a privacy and security checklist to evaluate Voice over the Internet Protocol (VoIP) videoconferencing software used between patients and therapists to provide telerehabilitation (TR) therapy.  In this paper, the privacy and security checklist that was previously developed is used to perform a risk analysis of the top ten VoIP videoconferencing software to determine if their policies provide answers to the privacy and security checklist. Sixty percent of the companies claimed they do not listen into video-therapy calls unless maintenance is needed. Only 50% of the companies assessed use some form of encryption, and some did not specify what type of encryption was used. Seventy percent of the companies assessed did not specify any form of auditing on their servers. Statistically significant differences across company websites were found for sharing information outside of the country (p=0.010), encryption (p=0.006), and security evaluation (p=0.005). Healthcare providers considering use of VoIP software for TR services may consider using this privacy and security checklist before deciding to incorporate a VoIP software system for TR.  Other videoconferencing software that is specific for TR with strong encryption, good access controls, and hardware that meets privacy and security standards should be considered for use with TR.Keywords: Voice over the Internet Protocol (VOIP), telerehabilitation, HIPAA, privacy, security, evaluation
Telerehabilitation: An Adjunct Service Delivery Model for Early Intervention Services
Authors: Cason Jana
Published: May 2011

Early Intervention (EI) services for children birth through two years of age are mandated by Part C of the Individuals with Disabilities Education Act (IDEA); however, personnel shortages, particularly in rural areas, limit access for children who qualify. Telerehabilitation has the potential to build capacity among caregivers and local providers as well as promote family-centered services through remote consultation.  This article provides an overview of research related to telerehabilitation and early intervention services; discusses the feasibility of telerehabilitation within traditional EI service delivery models; examines telecommunications technology associated with telerehabilitation; and provides hypothetical case examples designed to illustrate potential applications of telerehabilitation in early intervention.
Carbon Leakage from the Clean Development Mechanism
Authors: Rosendahl Knut Einar , Strand Jon
Published: May 2011

The Clean Development Mechanism (CDM) is an offset mechanism designed to reduce the overall cost of implementing a given target for greenhouse gas (GHG) emissions in industrialized Annex B countries of the Kyoto Protocol, by shifting some of the emission reductions to Non-Annex B countries. This paper analyzes how CDM projects may lead to leakage of emissions elsewhere in NonAnnex B countries. Leakage occurs because emissions reductions under a CDM project may affect market equilibrium in regional and/or global energy andprod-uct markets, and thereby increase emissions elsewhere. We also account for potential reverse or negative leakage effects in Non-Annex B from higher emissions cap in Annex B. Our conclusion is that net leakage typically is positive and sizeable, thus leading to an overall increase in global GHG emissions when CDM projects are undertaken. Leakage is greater when the different fossil fuel markets are more segregated. doi: 10.5547/ISSN0195-6574-EJ-Vol32-No4-2
Highly Efficient Solid‐State Dye‐Sensitized Solar Cells Based on Triphenylamine Dyes
Authors: Jiang Xiao , Karlsson Karl Martin , Gabrielsson Erik , Johansson Erik M. J. , Quintana Maria , Karlsson Martin , Sun Licheng , Boschloo Gerrit , Hagfeldt Anders
Published: May 2011

Two triphenylamine‐based metal‐free organic sensitizers, D35 with a single anchor group and M14 with two anchor groups, have been applied in dye‐sensitized solar cells (DSCs) with a solid hole transporting material or liquid iodide/triiodide based electrolyte. Using the molecular hole conductor 2,2',7,7'‐tetrakis‐(N,N‐di‐p‐methoxyphenyl‐amine)9,9'‐spirobifluorene (spiro‐OMeTAD), good overall conversion efficiencies of 4.5% for D35 and 4.4% for M14 were obtained under standard AM 1.5G illumination (100 mW cm−2). Although M14 has a higher molar extinction coefficient (by ∼ 60%) and a slightly broader absorption spectrum compared to D35, the latter performs slightly better due to longer lifetime of electrons in the TiO2, which can be attributed to differences in the molecular structure. In iodide/triiodide electrolyte‐based DSCs, D35 outperforms M14 to a much greater extent, due to a very large increase in electron lifetime. This can be explained by both the greater blocking capability of the D35 monolayer and the smaller degree of interaction of triiodide (iodine) with D35 compared to M14. The present work gives some insight into how the molecular structure of sensitizer affects the performance in solid‐state and iodide/triiodide‐based DSCs.
Predictions of porosity and fluid distribution through nonspherical‐packed columns
Authors: Caulkin Richard , Jia Xiaodong , Fairweather Michael , Williams Richard A.
Published: May 2011

For beds comprised randomly arranged nonspherical particles, the prediction and understanding of the packing characteristics and subsequent fluid flow through the resulting porous media is a longstanding problem for chemical and process engineers. This paper presents the application of a digital modeling approach to particle packing, in which no more than elementary physical concepts are used, with the model using collision points to predict trends in bed structures of particles of different geometry. Lattice Boltzmann modeling (LBM), coupled to the output of the packing model, is used to subsequently assess velocity distribution through the generated structures. Simulation results are compared with data available from the literature, as a means of model validation, where it is demonstrated that the combined approach of the digital packing algorithm and LBM provide a modeling capability that is of value to a range of engineering applications. © 2011 American Institute of Chemical Engineers AIChE J, 2012
Linear−quadratic optimal control and nonzero‐sum differential game of forward−backward stochastic system
Authors: Yu Zhiyong
Published: May 2011

An existence and uniqueness result for one kind of forward–backward stochastic differential equations with double dimensions was obtained under some monotonicity conditions. Then this result was applied to the linear‐quadratic stochastic optimal control and nonzero‐sum differential game of forward–backward stochastic system. The explicit forms of the optimal control and the Nash equilibrium point are obtained respectively. We note that our method is effective in studying the uniqueness of Nash equilibrium point.

Copyright © 2011 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
Green synthesis of lead sulfide nanoparticles by the lead resistant marine yeast, Rhodosporidium diobovatum
Authors: Seshadri Sachin , Saranya K. , Kowshik Meenal
Published: May 2011

Biosynthesis of nanoparticles using microorganisms has attracted a lot of attention in recent years as this route has the potential to lead to synthesis of monodisperse nanoparticles. Here, we report the intracellular synthesis of stable lead sulfide nanoparticles by a marine yeast, Rhodosporidium diobovatum. The PbS nanoparticles were characterized by UV‐visible absorption spectroscopy, X‐ray diffraction (XRD) and energy dispersive atomic spectroscopy (EDAX). UV‐visible absorption scan revealed a peak at 320 nm, a characteristic of the nanosize range. XRD confirmed the presence of PbS nanoparticles of cubic structure. Crystallite size as determined from transmission electron microscopy was found to be in the range of 2–5 nm. Elemental analysis by EDAX revealed the presence of particles composed of lead and sulfur in a 1:2 ratio indicating that PbS nanoparticles were capped by a sulfur‐rich peptide. A quantitative study of lead uptake through atomic absorption spectrometry revealed that 55% of lead in the medium was accumulated in the exponential phase, whereas a further 35% was accumulated in the stationary phase; thus, the overall recovery of PbS nanoparticles was 90%. The lead‐exposed yeast displayed a marked increase (280% over the control) in nonprotein thiols in the stationary phase. © 2011 American Institute of Chemical Engineers Biotechnol. Prog., 2011
Immobilization and stability of a Rhizopus oryzae lipase expressed in Pichia pastoris: Comparison between native and recombinant variants
Authors: Guillén Marina , Benaiges Maria Dolors , Valero Francisco
Published: May 2011

The stability of a soluble extract containing a recombinant lipase from Rhizopus oryzae (Cursive) lipase (rROL) produced by Pichia pastoris (Cursive), as well as that for the commercial extract containing the lipase produced by the native organism (nROL), was investigated. The results showed higher residual activity values of the commercial protein compared with the recombinant one. Moreover, two different kinds of support, the polypropylene powder EP100 and Eupergit®C, were tested to immobilize the enzymes. The residual activity of the immobilizated derivatives was also tested to determine whether their stability was enhanced. The results showed a slight improvement in rROL using both supports but a decrease in nROL using Eupergit®C. The study of the residual activity of soluble and immobilized enzymes was performed by means of a central composite rotatable experiment design. In addition, EP100 adsorption isotherms were determined. © 2011 American Institute of Chemical Engineers Biotechnol. Prog., 2011
Multi‐Criteria Analysis for Optimization of Sodium Chromate Production from Chromic Waste
Authors: Generowicz Agnieszka , Kowalski Zygmunt , Kulczycka Joanna , Makara Agnieszka
Published: May 2011

The proposal of application of multi‐criteria analysis and technological quality method for optimization of technological processes on the case study of sodium chromate production variants from waste was presented. The research on the use of chromic waste for the production of sodium chromate made it possible to determine the optimal process parameters. Technological quality method was used to define the value of criterions for multi‐criteria analysis while multi‐criteria analysis allowed determining the impact of criterions weights for ranking variants of technological process. Both methods in a complex way evaluate the degree of modernization of technologies, describing them qualitatively within the area of environmental, technical, and the economic effects of the proposed technological variants. Based on the proposed evaluating criteria both methods yield comparable results. The most advantageous alternatives provided realization of the sodium chromate production process with the use of in‐process recycling of chromic mud, off‐site recycling of chromic tannery waste and on‐site recycling of waste from the old chromic heaps.
Characterization of Chlorinated Tire‐Derived Mesoporous Activated Carbon for Adsorptive Removal of Toluene
Authors: Zhu Jianzhong , Liang Hao , Fang Jun , Zhu Jianguo , Shi Buchang
Published: May 2011

A series of chlorinated mesoporous activated carbons were derived from waste tires by pyrolysis, activation, and chlorination at different temperatures. The physical and chemical properties of the samples were studied by Brunauer–Emmett–Teller (BET) analysis, Fourier Transform IR Spectroscopy (FT‐IR), point of zero charge measurement, thermogravimetric analysis, and by testing their behavior as adsorbents for toluene removal. Our results showed that the tire‐derived activated carbon samples have highly mesoporous volumes and surface areas, and chlorination treatment has a slight effect on the pore structure. Lewis acidity of the sample increases after chlorination and the chlorine content increases from 0.24 to 2.32% with chlorination temperature increasing from 50 to 400°C. The higher the chlorine content, the more is the toluene adsorption. In comparison with the commercial carbon (F‐400), all the samples have significantly higher adsorption capacity for toluene due to the presence of mesopores, inductive effect of the partial positive chemisorbed chlorine and resonance effects of CCl structures. The mesopores probably render easier diffusion of toluene molecule to inner carbon matrix and the strong π–π interaction between toluene and CCl resonance structure in the carbon significantly affects the interplay bonding process thus enhances the toluene removal.