bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nanostructures for photon management in solar cells
Authors: Narasimhan Vijay Kris , Cui Yi 
Published: April 2013

Abstract
The concurrent development of high-performance materials, new device and system architectures, and nanofabrication processes has driven widespread research and development in the field of nanostructures for photon management in photovoltaics. The fundamental goals of photon management are to reduce incident light reflection, improve absorption, and tailor the optical properties of a device for use in different types of energy conversion systems. Nanostructures rely on a core set of phenomena to attain these goals, including gradation of the refractive index, coupling to waveguide modes through surface structuring, and modification of the photonic band structure of a device. In this review, we present recent developments in the field of nanostructures for photon management in solar cells with applications across different materials and system architectures. We focus both on theoretical and numerical studies and on progress in fabricating solar cells containing photonic nanostructures. We show that nanoscale light management structures have yielded real efficiency gains in many types of photovoltaic devices; however, we note that important work remains to ensure that improved optical performance does not come at the expense of poor electrical properties.
Metal nanoantimicrobials for textile applications
Authors: Giannossa Lorena Carla , Longano Daniela , Ditaranto Nicoletta , Nitti Maria Angela , Paladini Federica , Pollini Mauro , Rai Mahendra , Sannino Alessandro , Valentini Antonio , Cioffi Nicola 
Published: April 2013

AbstractResearch on the nanomaterials containing one or more transition metals is growing tremendously, thanks to the large number of preparation processes available and to the novel applications that can be envisaged in several fields. This review presents an overview of the selected studies in the field of antimicrobial textiles, employing bioactive nanophases of elements/compounds such as silver, copper, or zinc oxide. In addition, the history of use of these antimicrobials and their mechanism of action are shortly reported. Finally, a short description is provided of the deposition/preparation methods, which are being used in the authors’ labs for the development of the textiles modified by the novel nanoantimicrobials.
Archiving Aggregates of Individually Created Digital Content: Lessons from Archiving the Occupy Movement
Authors: Besser Howard 
Published: April 2013

AbstractWith the ubiquity of digital phones and cameras, our memory institutions will need to ingest an increasingly large number of born-digital media, much of it coming from personal archives. The high volume of this material will force collections to find smart ways to automate appraisal/selection, metadata assignment, and standardization of formats, or to convince contributors to do so. This article reports on ideas and methods developed by the group Activist Archivists to automate selection, metadata collection, and standardization of the born-digital media documenting the Occupy movement. Techniques include employing automatic time/date/location stamping, analyzing social media sites, producing guidelines for contributors, and asking for community involvement in selecting the material perceived as having the most enduring value.
Fluorescence diagnosis using 5-aminolevulinic acid in coloproctology/Fluoreszenz-Diagnostik in der Koloproktologie mittels 5-Aminolävulinsäure
Authors: Filonenko Elena V. , Urlova Antonina N. , Raszhivina Antonina A. , Sotnikov Veniamin N. , Nechipai Andrei M. 
Published: April 2013

AbstractMethods of fluorescence diagnosis (FD) with 5-aminolevulinic acid (5-ALA) have frequently been used for the detection of early cancer on the surface of the mucosa and skin. The objective of this study was to estimate the effectiveness of FD using Alasens (5-ALA) for the detection of malignant lesions in the colon.In the article, our experience of fluorescence colonoscopy is represented using Alasens (5-ALA) in 78 patients with colonic polyps. FD was performed using the visual assessment of fluorescence images in combination with local fluorescence spectroscopy.The sensitivity and specificity of FD with Alasens was 94.9% and 62.5%, respectively. The application of local fluorescence spectroscopy as a step of the combined approach allows the specificity to be increased from fluorescence colonoscopy from 62.5% up to 93.7%.
The effects of magnesium oxide on the thermal, morphological, and crystallinity properties of metallocene linear low-density polyethylene/rubbers composite
Authors: Alwaan Ismaeel M. , Hassan Azman 
Published: April 2013

Abstract
The effects on the thermal, morphological, and crystallinity properties of the different loadings of magnesium oxide (MgO) blended with 10% rubbers [9:1 natural rubber (NR)/epoxidized NR] and metallocene linear low-density polyethylene (mLLDPE) in the presence of N,N-m-phenylenebismaleimide (HVA-2) compatibilizer were investigated. Fourier transform infrared spectroscopy showed that the epoxy and double-bond groups were absent in the blends. The crystallinity degree of mLLDPE composites were determined based on the results of differential scanning calorimetry. The crystallinity of the blends was continuously increased by the loading of MgO compared with blend of 0 phr MgO. Based on thermogravimetric analysis, the degradation temperature of NR in the blends with MgO is significantly enhanced compared with a pure NR and 0 phr MgO blend. The observations of the scanning electron micrographs indicate that the HVA-2 had caused a cross-linking reaction in the rubber phase and the domains of the MgO are separated from the continuous phase (mLLDPE).
Topochemical modifications of mixed metal oxide compounds by low-temperature fluorination routes
Authors: Clemens Oliver , Slater Peter R. 
Published: April 2013

AbstractIn this review, we discuss recent developments in the use of low-temperature fluorination routes for the topochemical modification of mixed metal oxide compounds. By applying such methods, material properties (such as magnetism, superconductivity, electrical conductivity, and ionic conductivity) can be tuned in a wide range. Furthermore, oxide fluoride compounds are interesting from a structural point of view, and while differentiating between oxide and fluoride ions has proved to be difficult using diffraction methods, strategies (e.g., bond valence sum calculations) to overcome this problem have been shown to be possible. In addition, this review concludes with an outlook on future prospects in the field of oxide fluoride compounds.
Vibration analysis of sandwich beams with variable cross section on variable Winkler elastic foundation
Authors: Demir Ersin , Çallioğlu Hasan , Sayer Metin 
Published: April 2013

Abstract
In this study, free vibration behavior of a multilayered symmetric sandwich beam made of functionally graded materials (FGMs) with variable cross section resting on variable Winkler elastic foundation are investigated. The elasticity and density of the functionally graded (FG) sandwich beam vary through the thickness according to the power law. This law is related to mixture rules and laminate theory. In order to provide this, a 50-layered beam is considered. Each layer is isotropic and homogeneous, although the volume fractions of the constituents of each layer are different. Furthermore, the width of the beam varies exponentially along the length of the beam, and also the beam is resting on an elastic foundation whose coefficient is variable along the length of the beam. The natural frequencies are computed for conventional boundary conditions of the FG sandwich beam using a theoretical procedure. The effects of material, geometric, elastic foundation indexes and slenderness ratio on natural frequencies and mode shapes of the beam are also computed and discussed. Finally, the results obtained are compared with a finite-element-based commercial program, ANSYS®, and found to be consistent with each other.
Utilization of water reed in production of various insulation panels
Authors: Karademir Arif , Yetis Ferhat , Imamoglu Sami , Varlıbas Hulya 
Published: April 2013

Abstract
Some panels and particleboards were made from reed mats and blends of reed-wood chips to be used inside buildings for sound and heat insulations. It was seen that the outer layers of the reed body (spike) was almost water resistant and exceptionally resistant to the penetration of common adhesives. Therefore, the panels from stitched reed mats exhibited very poor mechanical strength. The sound transmissions of such panels (1–3 km/s) made with various combinations, however, were recorded to be excellent compared with that of particleboards made of wood (17 km/s). Blends of reed chips (2 cm) and wood chips, however, gave particleboards with better mechanical properties (5–17 MPa) than that of panels made from reed mats (2 MPa). An increasing amount of reed chips in tested particleboards was recorded to be improving both sound and heat insulations from 17 to 6 km/s and from 0.34 to 0.27 W/mK, respectively. The bending strength of samples, however, was reduced from 26 to 5 MPa. Thickness swelling was also noted to increase from 18% to 85% due to reed chips addition. It was concluded that the outer layers of water reeds should be modified via chemical and/or enzymatic methods to increase the interfacial bounds between adhesives.
Accurate Prediction of Dissociation Pressures of Natural Gas Hydrates Containing Carbon Dioxide and Hydrogen Sulfide for Efficient Flow Assurance Phenomena
Authors: Mekala Prathyusha , Sangwai Jitendra S. 
Published: April 2013

Abstract
Information on the phase behavior of gas hydrate is vital for several mitigation techniques to control their formation in pipelines and surface facilities for efficient flow assurance during the production and transportation of natural gas and reservoir fluids. The pipeline environment (high pressure and low temperature) favors the formation of natural gas hydrate, which is one of the main elements in the flow assurance issues and this has to be taken in to account very seriously. Depending upon the composition of the gas produced, hydrates can form different physical structures and thus require careful attention whole modeling their phase behavior. The better thermodynamic models are necessary to design and understand the phase behavior of produced trapped natural gas from natural gas hydrates from subsea environments. Most of the models available in an open literature are primarily applicable at relatively low pressure condition.
In this work, model of Chen and Guo along with the three famous Equation of States (EoS), namely, Peng-Robinson (PR), Peng-Robinson-Stryjek-Vera (PRSV) and Soave-Redlich-Kwong (SRK), are used to model the hydrate phase behavior at high pressure conditions. Their efficacy to model phase behavior for hydrates of pure natural gases and gas mixture containing H2S and CO2 is presented and tested against the experimental data available from open literature at high pressures conditions.
The developed model uses the published Lennard-Jones cell potentials of typical gas species that form hydrates assuming the adsorption would be carried out in the cavities of hydrate structures. We optimized the computed phase diagrams based on three EoS with experimental phase diagram data from literature and determined the model parameters with less percentage average deviation.
The present papers discusses about modeling of the phase behavior of binary gas mixture hydrates like CH4-C2H6, CH4-CO2 and CH4-H2S. Model predictions are validated against the experimental data from the literature, and observed to be in well agreement for high pressure range which helps in the flow assurance. Such models shows potential of their application in understanding flow assurance phenomena at higher pressure.
An Integration between Geological and Reservoir Engineering Data to Design a Conceptual Waterflood Program
Authors: Abu El Ela M.. , Samir M.. , Abdel Monem A.. , El Tayeb S.. , Sayyouh Helmy 
Published: April 2013

Abstract
Field development plan is a set of operations and decisions by which oil reservoirs are identified, evaluated and developed. Making smart reservoir development plan depends on the ability to analyze and integrate the available data.
In this work, a conceptual short-term study was performed with the objective of determining the optimum conditions for required application of waterflooding pilot project in Upper Bahariya Formation (Ferdaus field / Egypt) in order to maintain the pressure and increase the oil production rate.
The integration between the geological and engineering data identified the reservoir structure of Upper Bahariya formation which includes two isolated formations: Upper Baharia 2 and Upper Baharia 3. The original oil in place of Upper Baharia 2 is about 5 MMSTB, while for Upper Baharia 3 is about 11.9 MMSTB.
An efficient monitoring program design, for the waterflooding pilot, including three different injection scenarios with 12 response cases, to investigate the uncertainties of the static model are presented. The results of the pilot study scenarios are very encouraging to implement the waterflooding pilot. Recoverable amount of 2 MMSTB will be achieved upon performing the full scale waterflooding project. Such study is an original conceptual contribution to the knowledge of the integration between geological and reservoir engineering data to design of a comprehensive waterflood program.
The Polymer Flooding Technique Applied at High Water Cut Stage in Daqing Oilfield
Authors: Yuming Wang , Yanming Pang , Zhenbo Shao , Peihui Han , Rong Li , Ruibo Cao , Xianhua He 
Published: April 2013

Abstract
Daqing Oilfield has complex geological conditions, multiple reservoir layers and severe areal and vertical heterogeneity. After feasibility study, polymer flooding is selected as the dominant EOR technique. Polymer flooding in Daqing Oilfield has experienced four stages: laboratory study, pilot tests, industrial field tests and commercial application. Reservoir engineering techniques, such as individual injection parameters design, separate layer polymer injection, in-depth profile modification and comprehensive adjustment, are discussed and the technical-economic effects of polymer flooding are evaluated. The result shows that due to the conversion from water injection to polymer flooding at the water cut of 90-95%, the recovery factor is raised by 13.3% (OOIP) at the water cut of 98% compared to water flooding. At the same time, production rate is increased and water injection volume is reduced. The average operation cost of polymer flooding is $0.1-2.83 /barrel lower than that of water flooding. The polymer flooding of Daqing Oilfield at high water cut stage has better technical-economic effects than full term water injection. Until the end of 2011, the oil production of polymer flooding has exceeded 1000×104 ton(7.31Mbbl) ten years in a roll, and the cumulative production has reached 1.58×108 ton (1.15Bbbl). Polymer flooding has become a major technique in the sustainable development of Daqing Oilfield.
New Approach for Pulse Test Analysis
Authors: El-Khatib Noaman 
Published: April 2013

Abstract
New concepts are introduced to define time lag and response amplitude. The points of extreme pressure values (maxima and minima) are used to define the time lag and pressure response amplitude. The points of maxima and minima are found by equating the pressure derivative to zero. This results in a more accurate solution of the governing equations. The developed method is based on well-defined and easily locatable points, making the method amenable to automatic analysis by computer procedures. It eliminates the need for manually plotting of parallel tangents to the pressure profiles which is subjective, less accurate and does not amend itself to automatic processing.
The solution is used to construct correlation charts for relative time lag and dimensionless pressure response amplitude vs. the dimensionless cycle time for different values of the pulse ratio. The correlation charts will be used to analyze results of pulse testing to obtain interwell reservoir properties, namely transmissibility kh/μ and storativity hϕct. Simulation examples are generated to validate the developed procedure. Results indicate the robustness of the developed method and its superiority over the conventional pulse test analysis method.
The developed correlations show that the relative time lad decreases linearly with the dimensionless cycle time on a log-log plot. Results also indicate that the relative time lag and dimensionless pressure response amplitude decrease with pulse ratio for odd pulses and increase for even pulses.
First Implementation of CRA Casing in Sour HPHT Reservoirs in Deep Wells in Kuwait
Authors: Al-Saeedi M. J. , Al-Enezi D.. , Sounderrajan M.. , Saxena A. K. , Gumballi G. K. , McKinnell D. C. 
Published: April 2013

Abstract
Kuwait Oil Company has embarked on an ambitious project of drilling development wells to exploit the Najmah-Sargelu and Middle Marrat reservoirs at depths of 14,000 to 17,000 ft. These Jurassic formations consist of layered shales and limestones, which can be heavily fractured and highly pressured. The wells drilled to these prospects are very challenging because of HPHT conditions, narrow pore/fracture pressure windows, and high levels of H2S and CO2.
During drilling and production high concentrations of H2S and CO2 have been recorded. Given the strategic importance of these gas prospects, a study was undertaken into the metallurgy of materials planned for these production wells. With high levels of toxic gases and HP conditions, the severity of sour service was evaluated to be within the most severe area when referencing NACE standards. Dependent on well bore fluid and onset of any water production, Stress Corrosion Cracking (SCC) and Weight Loss Corrosion could occur leading to material failure and lost production. After this study, the use of CRA materials was recommended in future wells to counter these challenges.
The application of CRA for down hole tubular and surface wellhead equipment has gained wide acceptance in sour fluid service in recent years especially in HPHT wells. CRA usage has increased to; eliminate intensive corrosion inhibition programs, reduce maintenance costs and enhance safety. Considering the key parameters influencing corrosion properties of CRA (temperature, partial pressure of H2S and CO2, pH environment, chloride concentrations), it was decided to specify the use of 28 Cr CRA material for these Jurassic gas wells. This paper will discuss the initial study of the material metallurgy, the well design, the specification of tubulars and wellhead, special procedures necessary to run these exotic materials plus details of actual operations in the first wells.
Geochemical Evaluation of Hydrocarbons and their Potential Sources in the Central and Meridional Atlas of Tunisia
Authors: Belhaj Mohamed A.. , Saidi M.. , Bendriss W.. , Mahmoudi S.. , Bouazizi I.. 
Published: April 2013

AbstractThe Central and Meridional Atlas of Tunisia, contains significant accumulations of oil in early Cretaceous aged reservoirs. The active cretaceous hydrocarbon system is a product of unique paleogeographic and tectonic events that led to cretaceous deposition of organic-rich source rocks.The analysis of different sources rocks from the Central and Meridional Atlas of Tunisia indicates that the Albian Lower Fahdene Fm has a substantial oil-generation potential. The Cenomanian-Turonian Bahloul Fm exhibits fair to high organic matter content and petroleum potential and is immature to mature. The Jurassic source rock, located in the Southern part of this area, exhibits fair to good organic matter content and petroleum potential.Molecular characterization indicates that most of the produced oils appear to be sourced from a predominantly shaly marine and mature source rock deposited in suboxic to oxic environment. Oil stains located in the northern part of the area seems to be sourced by a marly or argillaceous limestone. Oil-oil correlations and molecular characteristics of selected source rock samples and maturation models suggests that oils were generated from similar source rock and/or organic facies. The Lower Fahdene Fm is the best source candidate to generate these fluid samples. The integration of benzocarbazoles as geochemical molecules tracer has permitted a relative estimation of the lateral migration distance for the different accumulations of the area.
Thru-Tubing Inflatable Straddle Packer Assembly Enables Selective Treatment of Multiple Zones and Improves Productivity
Authors: Kothiyal M. D. , Parasher A.. , Qutob A. H. , Cooper R. J. , Forsyth G. R. 
Published: April 2013

Abstract
The subject well is an onshore oil producer located in Cairn Energy India's Rajasthan block. The well had stratified sand sections completed with 4-inch inflow control device (ICD) screens and isolated by swellable packer assemblies. The well was put into production at a rate of approximately 1,000 bopd; however, due to formation damage – notably paraffin and scale - the well could not sustain production and eventually ceased.
Our objective was to selectively stimulate 15 ICDs using coiled tubing. The well had a minimum restriction and a larger setting diameter which warranted the usage of coiled tubing deployed inflatable straddle packer system. This enabled passage through the restriction and setting in the larger outer diameter to selectively treat each zone by mechanically diverting the stimulation fluid.
The challenge was significant. Multiple zones required treatment in a single run by performing 15 multi-settings, maintaining seal integrity following each set, and returning the tool to its original outer diameter for retrieval. The well was deviated at 74 degree which challenged accessibility.
The assembly was run successfully and managed to selectively stimulate all required zones in one trip. Using this application, we confirmed that all treatment fluid was effectively sealed and treated by diverting the treatment fluid directly into the required zone, preventing more permeable sections absorbing most of the fluid, and ensuring the treatment chemicals were used in a cost effective manner. The single coiled tubing run avoided multiple runs to isolate sections using plugs. The well subsequently began to flow once lifted with nitrogen, positively indicating that the ICDs were effectively cleaned and the zones successfully treated.
This case demonstrates the innovative use of thru-tubing wellbore isolation techniques to effectively enhance production in wells with challenging configurations and operating parameters. This study further paves the way for similar interventions in wells with similar characteristics.