bluuebunny/crossref_metadata_2025 huggingface dataset:
Technical, Economic & Legal Considerations for Successful Projects in the Oil Industry
Authors: Cedeno I. , Moreno M. S. , Polit E.
Published: November 2015

This paper proposes a multidimensional approach for the integration of technical, economic and legal & contractual components and the interrelation of the parties involved in the development of Upstream & Downstream projects in the oil industry –and not on an individual, separate, or partial basis– in order to efficiently and effectively achieve the success of the project through the optimal usage of investments and resources while minimizing risks which may result in losses for the parties or the failure to reach jointly the mutually agreed goal.

Based on projects developed in Ecuador in the oil industry which outcome was a success and/or a failure, we will identify through the variables which contributed to said success and/or failure and the interrelation among them. The success and/or failure is not a lineal function of the variables, as these individually do not lead to the outcome but it is their synergy which unfolds the results.

This method has only been applied on a retrospective basis, that is, after the fact, in order to revise actions and steps taken to determine the reasons for failure. The application of the multidimensional approach have enabled us to reach the conclusion that in certain projects results could have been different. It will only be useful if new future projects are analyzed a priori and results evidence positive consistency.

Without foundations, it has been thought that the oil industry as an extractive industry is only a basic industry which does not vary or incorporate and/or require methodologies to effectively and efficiently optimize the execution of projects. To the contrary, this industry has led the way for the development of other industries. Based on the universal nature of the oil industry, we may incorporate an educated analysis that will be pioneer for other industries.

Frequently it has been observed that there is a divorce among the technical, economic and legal professionals managing an oil industry project unaware that joint efforts will provide synergy to the analysis, in order for the final result to be more effective and efficient than those results originated from individual efforts. This Paper incorporates a multidimensional analysis for the development of projects in the oil industry.
Strategy Model for Petroleum Contracts: A Holistic Sensitivity Analysis of Oil Royalties to Hydrocarbons Commercialization.
Authors: Bravo Reynaldo Cervantes , Huerta Víctor Alexei , Chun Néstor Palacios
Published: November 2015

The development of a petroleum exploitation strategy is essential for any country for developing its petroleum resources. Petroleum exploitation strategy includes a series of policies relating to licensing, taxation, royalty, and legal instruments. Contractual agreements are developed by the state in order to ensure the orderly development of petroleum exploration and production. In the absence of a clear petroleum exploitation strategy, the international oil companies of Peru and Latin American would not be able to assess the political and economic risks to the preservation of the reserves in a focus of commercialization.

The proposed methodology comes from a study of the forecast of WTI oil price in its inference (0.650%) annual, (0.645%) monthly as in its daily. It is subject to progressive decreasing jumps every five years at 50% for the factor of the prospective increase (PI), caused by external agents (Positive turning: 30.48%; Negative Turning: – 36.04%), then evaluate the 3 scenarios (Proved Developed Reserves,1P and 2P) with case studies for WTI: Low, Base and High.

The sustainability of the Reserves status is initially defined from a deterministic approach, and followed by the development of a programming language for the interpretation of the simulation of royalties under a probabilistic approach in the contractual period.

Since the International Oil Companies are major sources of the intensive capital, and sophisticated technologies needed for exploration and development of petroleum resources, it is essential for a country to formulate a coherent and well-balanced petroleum exploitation contractual strategy. This should be consistent with its social and economic goals and at the same time allow the international oil companies to generate economic profits that in some way relate to the level of risk involved in obtaining these profits and setting a rate of minimum refund of 100% since 2020 year.

For 2026, it seeks to have an incentive by the State regarding the minimum royalties for oil light (35%), and raw Median-Heavy (25%) independent of WTI oil price variability in the probable and possible reserves in addition to the incorporation of Integral rate of refund. Likewise, there is a tolerance of up to 25% in the return on investment for the company to verify an additional investment in the development of resources within the last 10 years of the oil contract.

Based on the Forecast WTI and stage of development (1P) simulation explains a range of royalties between (35-40) % for light crude and, (25-27) % for Medium-Heavy crude; under the conditions of investment recovery of 50%.
Integrated Applications of Fiber-Optic Distributed Acoustic and Temperature Sensing
Authors: Hveding Frode , Porturas Francisco
Published: November 2015

Distributed Acoustic Sensing (DAS) and Distributed Temperature Sensing (DTS) measurements are leading edge technologies which are adding great benefits and solutions to a series of well and reservoir monitoring surveillance and management challenges. The main goal is to optimize the reservoir performance to achieve higher ultimate recovery, higher production, monitor overburden geomechanics, acquire wellbore seismic data, and monitor well integrity at a lower cost in both conventional and non- conventional reservoirs.

DAS in combination with DTS offer qualitative and quantitative data for understanding the fluid dynamics both near and far from the wellbore to aid in decision making for optimal reservoir management. This is where fiber-optic DTS and DAS technology either permanently installed or temporarily deployed in the well can provide information on-demand at a low cost and minimal risk of failure.

Enhanced reservoir management employs multiple integrated technologies for optimal area sweep, drainage, and recovery, as well as increasing the productivity index or injection conformance at the well, group and or field levels. Composite carbon rod deployed fiber-optic Distributed Temperature Sensing (DTS) and Distributed Acoustic Sensing (DAS) systems are one of the innovative technologies that has become available for real-time monitoring in support of advanced intervention methods and enhanced reservoir management.

In non-conventional reservoirs fiber-optic are useful for monitoring hydraulic fracturing operations, and flow profiling during production. DAS and DTS measurements add a new dimension to gain knowledge from each perforation stage in long horizontal wells to optimize completions design and increase production efficiency and well performance.

This paper presents a detailed description of the main steps followed to deliver timely and valuable DTS/DAS solutions and shows results from key field applications.
Commingled Reinjection of Cuttings and Produced Water Provides a Zero-Discharge Solution for the Development Phase of the Pirana Field in the Peruvian Amazon Region
Authors: Poclin H. R. , Watanabe J. F. , Ortiz H.
Published: November 2015

Drilling and production operations in sensitive areas require an effective and efficient waste management plan to minimize the impact on the environment, especially when environmental legislations are strict. Waste management is a decisive factor during oilfield planning operations from an environmental and economic perspective. Often, the waste management method used depends on the type of operation (exploratory drilling, development drilling or production) and the environmental regulations. The waste related to drilling operations can include solid waste such as drilling cuttings and chemical products used for drilling fluid preparation, and liquid waste such as drilling fluid, contaminated rainwater and rig washes. Production waste comprises (mainly) completion fluids, produced water and oil-contaminated fluids. Cutting re-injection (CRI) technology is an accepted method for disposal of drilling cuttings and drilling-associated liquids. Produced water is usually injected into a subsurface formation for final disposal or to maintain reservoir pressure during production.

According to conventional oilfield practices, both disposal options occur separately in different wells. Currently, commingled injection of both drilling cuttings and produced water in a same well is an interesting option if it is properly addressed.

The article presents the commingled re-injection of cuttings and produced water during the development stage of the Pirana field as a cost-effective and environmentally friendly waste management method. The development of the Pirana field began in 2013 with seven producer wells and one injector well. During the 2013 campaign, the injector well was dedicated to only the re-injection of cuttings. After production started (at the end of 2013), the well was dedicated to only produced water injection until the beginning of the second drilling campaign (in 2014), where five additional wells were drilled and commingled injection began in the same injector well. Produced water was injected with periodic injections of drilling waste.
Implementing Long Stroke Reciprocating Rod Lift in Re-Entry Wells
Authors: Villacis Nelly , Solá Ana , Alvarez Fabián
Published: November 2015

This paper describes the results of implementing a Long Stroke Pumping Unit (LSPU) on a re-entry well at Auca field, Ecuador which is operated by the National Oil Company (NOC) Petroamazonas EP.

The optimization of the artificial list system on the selected well, was recommended after careful examination of several parameters such as: mechanical constraints due to well geometry, high depth and high degrees of deviation, low rate of production, low API gravity that in conjunction caused the existing hydraulic jet pump completion to operate at lower efficiency rates.

A few of the benefits of proposing an optimization on the lifting method are: The use of a LSPU with its 288 in stroke length allows for fewer reversals and thus less cycles in the downhole equipment allowing for a longer run life when compared to other pumping units.Tubing-sucker rods lateral loads will be evenly distributed with an appropriate guiding program.Specialty Downhole equipment such as an insert pump anchor, and a two-stage hollow rod pump allows the operator to save in intervention times up to 40% in costs since does not require use of workover, but only a flushby truck unit

In addition energy consumption is reduced without affecting the rate of production of the well, thus with all these considerations reciprocating rod lift with a long stroke pumping unit was selected.
Unconventional Completion Design for Deep Geothermal Wells
Authors: Okech Roy Radido , Liu Xiaolei , Falcone Gioia , Teodoriu Catalin
Published: November 2015

Harnessing geothermal energy faces many of the challenges encountered in the exploration and production of oil and gas. Deep drilling is a necessity to attain sufficiently high temperatures for successful recovery of unconventional geothermal energy, such as in Enhanced (or Engineered) Geothermal Systems (EGS). The challenge of deep geothermal exploitation is comparable to that posed by high-pressure, high- temperature oil and gas projects. Accessing such deep targets, and the need for suitable well completions, means operators incur increased capital and operational costs.

To date, the implementation of EGS, following the original Hot Dry Rocks (HDR) model, has been dogged by technical problems, lower-than-expected performance and poor public image, as they typically require the "engineering" of the reservoir by artificial stimulation in order to create the necessary heat exchange in the subsurface.

Here, conventional and unconventional deep geothermal development well concepts are reviewed, breaking down the technologies into three categories: doublets, single well (open loop) solutions and single well (closed loop) heat exchangers.

This paper then focuses on the original Borehole Heat Exchanger (BHE) concept for shallow applications, and - based on recent experience with medium-depth BHEs for direct use/district heating - discusses variations proposed in the public domain for deep geothermal systems, with the ultimate goal of generating electricity under current economic conditions.
A New Reservoir Classification Based on Pore Types Improves Characterization - PART B
Authors: Jonathan Soto O. , David Soto O. , Rodolfo Soto B.
Published: November 2015

This is the second of a two-part article of a new reservoir classification based of pore types. We discussed in the first article a new methodology developed in order to classify all kinds of reservoirs worldwide: fracture, matrix, vugs, or combinations of these using the cementation factor, mvariable, and fuzzy logic concepts. The new classification presented was based on a 2D Model and we identified at least five types of reservoirs according to pore types. This article provides the updated reservoir classification using a ternary diagram based on fractures, vugs and/or intercristaline pore systems. We show in this paper how to use core, log, field data and fuzzy logic to build a confident petrophysical model, for complex reservoirs; and how to determine which kind of reservoir belongs to the new classification; and discuss the best practices of how to exploit and increase hydrocarbon production and reduce the uncertainty of the original oil in place calculation.
Key Parameters to Revitalize Mature Oil & Gas Fields
Authors: Quiñones V. A. , Bravo R. J. , Chun N. Palacios
Published: November 2015

Nowadays, exploration efforts are becoming harder taking into account that worldwide new hydrocarbons have been discovered in frontier areas such as deep water fields and artic oil, as well as, remote, almost inaccessible and environmentally sensitive places, such as oil and gas fields in the Ecuadorian and Peruvian jungle. Monetizing hydrocarbons in such sensitive places require time and addressing technology, logistics, commercial and environmental-social issues.

Many companies and governments have shifted his strategies to look "new oil" in mature fields either by redefining development strategies or by applying enhanced recovery technology. Based on experience and application in many oilfields in the region, some key parameters were identified as critical to bring new life to brown fields.

Based on worldwide experience, three (03) key parameters are considered critical to incentive and promote "re-development strategies" in brown fields in Peru for new bidding processes ratio of proved reserves replacement, royalty taxes based on financial performance (ratio between NPV and CAPEX) and an "incremental profit" for secondary and tertiary oil.

The purpose of defining a 100% ratio of proved reserves replacement is to set a threshold production curve for bidders that will assure an extended production life of the hydrocarbon asset even after finalizing the new contract period. The ratio of proved reserves replacement is focused on fostering short-term strategies such as production optimization, reactivation of wells and infill drilling; since this key indicator is focused on increasing progressively proved reserves as companies redeveloped the fields, they will be comfortable to deploy investments under "low risk scenarios" to increase recovery factor in mature fields. In addition, the application of the proved reserves replacement ratio in new bidding processes will help state to address long-life reserves to production ratio and sustainability of country's energy supply.

On the other hand, the definition of a tax royalty based on financial performance will address a window range of multiple simultaneous scenarios in which the profits of government and companies concur to equitable financial performance of 50%. This provides a more reasonable timeline for companies to deploy investment and help the state and contractors to arrive to a fair distribution of oil rents.

The incorporation of special tax regimes and rates, as well as, a preferential royalty in new oil contracts will push companies to look new ways to apply technology in mature fields (multilateral wells, modern completion systems and enhanced recovery processes) so as to probable and possible reserves, as well as, contingent resources might be converted into proved reserves. The index of Proved Reserves Evolution and the Ratio of Proved Reserves Replacement would be useful to account for these movements.
Understanding Controlled Salinity Waterflooding in Carbonates Using Streaming Potential Measurements
Authors: Al Mahrouqi D. A. , Vinogradov J. , Jackson M. D.
Published: November 2015

Modifying the composition of injection brine can cause wettability alteration and lead to enhanced oil recovery (EOR) from carbonate reservoirs. The two main approaches are: (1) dilution of injected brine and (2) selective modification of the concentration of potential determining ions (PDIs) such as Ca2+, Mg2+ and SO42-. Each of these approaches will modify the surface charge of carbonate mineral expressed in terms of the zeta potential. Here we reports measurements of the zeta potential of intact carbonate samples obtained using the streaming potential method. This method allows us to directly link zeta potential and oil recovery in the same coreflooding experiments. We begin by using single-phase (brine only) experiments to investigate the effect on zeta potential of dilution and PDI modification using seawater as a reference injection brine composition. We then use multi-phase experiments (brine displacing oil) and carbonate samples at different initial wetting states to determine the correlation between injection brine composition, zeta potential, EOR and initial wetting state, using the same brine compositions as in the single-phase experiments. We find that typical formation brine yields a positive zeta potential, whilst seawater yields a negative zeta potential. Consequently, injection of seawater leads to a change in the polarity of the zeta potential and therefore affects fluid-rock interactions. This in turn affects oil recovery. Dilution of injected seawater and an increase in SO42- concentration both yield a more negative zeta potential compared to the seawater reference case. However, the change in zeta potential observed when adding SO42- is less than for bulk dilution. The magnitude of the zeta potential increases in the presence of an oil phase after aging and similar increase was observed on diluting the injection brine. In the experiments reported here, incremental oil production was not observed. We suggest that the increase in the zeta potential, and consequent increase in the electrostatic repulsion between the similarly charged mineral-brine and oil-brine interfaces, explains why most of the oil is produced during first brine injection. Other samples, which were not aged, yield no change in zeta potential compared to water-wet cases within experimental error.
Geosteering Operations Using Spectral and Azimuthal Information in the Eastern Llanos Basin- Colombia
Authors: Ballesteros J. , Bravo G. , Cerchiaro J. , Perez M. , Rincon C.
Published: November 2015

This paper highlights the results obtained during the drilling a horizontal well using azimuthal/spectral information to geosteer the well at the top of the reservoir. It also documents the structural/stratigraphic changes along the navigated section by analyzing the reaction of the radioactive isotopes in the overlying and underlying clays of the reservoir.
Abrasive Perforation Technique Optimize Production and Avoid Reservoir Damage in COCA Field Ecuador
Authors: Carrera L. , Morales O. , Sierra F. , Teran N. , Monge A. , Alvarez J.
Published: November 2015

There are several techniques to optimize production and avoid reservoir damage caused in the different phases of the development of oil wells (perforation, completion, production and workover), ranging from the control of water, chemical stimulation, mechanical stimulation, fracture, re-perforation of producing areas, etc.

In the case of phase completion, holes are perforated through canyons to connect the reservoir with the wellbore and get well production, however this technique, often not doing its job, because it does not exceed the damaged area, produced in the drilling phase, when applying sludge systems or the primary cementing is performed, brings further cause damage to the compacted in the vicinity of each hole area.

Abrasive perforation technique was used in 1958 approximately and thanks technological advances in the field of materials and chemistry, has had substantial improvements, has created new expectations for avoid formation damage and hence an improvement in the production of oil producing wells.

In order to analyze and predict the well Productivity, it is necessary to perform an appropriate perforating analysis; this can be achieved integrating Petrophysics, Geomechanics, Reservoir and Production Domains. For an advanced Perforating design a clear understanding of rock characteristic, depth of damaged zone and reservoir behavior is used in the Perforating simulation. This enhances the right selection of charges and ensures they will overpass the altered zone.

Abrasive perforation technique has been used to optimize production from oil wells and avoid the reservoir damage to the drilling and completion phase, replacing conventional techniques shooting. This methodology was implemented in Coca Field. This helped to optimize and predict the productivity of the wells.
Acoustic and Microresistivity Borehole Image Logs and Core Data Integration in Well DN-22, Drago Field, Oriente Basin, Ecuador
Authors: Badillo V. , Pérez J. A. , Rengel R. E.
Published: November 2015

Studies of petroleum reservoirs are based on a multidisciplinary integration focused on developing 3D models that honor reservoir heterogeneities; the sedimentological and stratigraphic models play the most important role to honor these heterogeneities; in order to obtain good models it is important to acquire and integrate the highest volume of well data, preferably state of the art technology. This paper presents how electrical log-core data integration obtained a correlation between lithology, lithological accessories, sedimentary structures, structural features, fossils, ichnofossils and fluid impregnation, among others, from the interpretation of two hundred and twenty nine feet of a sedimentary sequence within core data and a high-resolution acoustic-resistivity image log from well DN-22 in Drago field. High-resolution borehole image logs are much more cost effective as compared to coring and subsequent analysis.

From the analysis of the features associated with rock factory (grain size, sorting, roundness) and other associated features like sedimentary and post-sedimentary processes (lithological accessories, fossils traces, diagenetic features), sedimentary facies were identified, which were correlated and adapted to existing sedimentary facies catalog and used for Drago field. Likewise, based on patterns and characteristic responses seen in resistivity and acoustic image log (coloring and shading contrast, texture, clasts, clay laminations, fossils traces, fossils), electrofacies were identified and framed into the same facies catalog. The resulting analysis established eight sedimentary-electrofacies, this contributes to further extrapolate detail sedimentological analysis for coming wells in this field by using high-resolution image logs. This study is unique in the area and will help to better characterize rock properties for field development.
Determination of Principal In-Situ Stress Magnitude from Well Logs in Unconventional Reservoirs: A Practical Application in Willesden Green Field, Canada
Authors: Urban Edgar , Aguilera Roberto
Published: November 2015

A methodology to determine and delimitate the magnitude of the principal in-situ stresses in the Glauconite Formation of the Willesden Green Field in the Western Canada Sedimentary Basin (WCSB) is presented. The result is used to correlate with several failure scenarios including confirmation of hydraulically fractured zones and to optimize net stress conditions for drilling and wellbore stability.

Geomechanical rock properties (Poisson's ratio, Young's Modulus, Biot vertical constant, rock strength, and the coefficient of angel friction) and the minimum horizontal stress (Shmin) are calculated from well logs. The Mohr failure criteria is considered in other to determine possible failure magnitude of normal stress. Based on the minimum horizontal stress, the magnitude of the maximum horizontal stress (Shmax) is delimited. This permits estimating failure magnitudes of normal, reverse, strike-slip faulting planes, wellbore and tensile breakout scenarios.

Based on the theory of wellbore equilibrium, the Shmax is calculated in the fractured interval. This is corroborated with different failure scenarios predicted with the Mohr-Coulomb envelopes, and the unconfined rock strength (UCS) estimated from well logs.

The stress polygon that describes the in situ stress magnitudes limitations before failure for the Willesden Green Field is elaborated, and defines a very low-stress zone in the highly gas saturated and permeable interval. The polygon is suitable for drilling design and geomechanical analysis, particularly in those intervals where wellbore stability may be a problem.

The methodology can have practical and wide application in several fields where the predictions are limited due to restricted geomechanical information. The approach permits a quick delimitation of in-situ stresses valuable in those reservoirs with wellbore stability problems due to abnormal pressures.
Efficient Fractured Reservoir Simulation Using Lattice Boltzmann Method
Authors: Benamram Z. , Tarakanov A. , Nasrabadi H. , Gildin E.
Published: November 2015

In this paper, for the first time, a comprehensive methodology for the application of a generalized lattice Boltzmann model towards simulation of fluid flow within a hydrocarbon fractured reservoir is presented to validate its use as a reservoir simulation tool. The lattice Boltzmann method simulates fluid flow by defining a system with microscopic flow characteristics. In this method, the fluid consists of fictitious particles (mass fractions). These particles propagate (stream) and collide. The method assumes discretization of the physical system in both space and time. In space, the particles are allowed to move on lattice nodes. Interaction (possible collision) of particles is evaluated at these time steps. The interaction step is designed in such a way that the generalized Navier-Stokes equation is valid for the time-average motion of the particles.

The focus of this work is the formulation of precise boundary conditions on the surface of fractures and the wellbore. In addition, the set of dimensionless parameters that govern the evolution of the pressure profile is redefined. Pressure profiles are presented visually throughout this paper to provide the reader insight how such a product would be utilized by the petroleum engineer.

Most importantly, the methodology is tested against commercial software and results show excellent agree-ment for both homogenous and heterogenous reservoir cases. This strong agreement provides motivation for the oil and gas community to expand this model towards more complex subsurface conditions.
Wells Trajectory Optimization in Low Thickness Zones by Applying Geosteering Azimuth Tools
Authors: Ballesteros J. , Bravo G. , Cerchiaro J. , Perez M.
Published: November 2015

The azimuthal measurements tools used for geosteering in zones with low thickness, low lithological contrast and lateral changes have provided great benefits to optimize real time decision-making and perform geo positioning of trajectories within the different reservoirs.
Strengthening Sustainable Development in Five Communities in the Bermejo Field, Ecuador
Authors: Vega D. , Paredes D. , Martellotta P.
Published: November 2015

This project encompasses strengthening sustainable development in five communities in the Bermejo Field, Ecuador, by means of a Project Advisory Board (PAB). The PAB is made up of members of the community and acts as an external advising entity. It represents the interests and expectations of the community, and decides which social projects will be carried out.

The main problem we identified was poor management among the people with regards to the promotion of sustainable development throughout the communities. Also, due to the technical limitations that arose in accurately implementing projects and that the projects were executed in isolation, without the help of the community, we saw a decrease in financial income. As a result, the community members lost motivation, and neglected their projects and crops because of the low profitability.

In order to create the PAB, we identified community leaders from among families that managed the project. Each leader was trained in leadership and organizational skills, management and productive project management.

Following this, the trained leaders were appointed as members of the Project Advisory Board through community meetings. Then, the leaders, together with the community, drafted a regulation to determine the structure of the PAB and another for the presentation of projects.

The Project Advisory Board identified action areas as opportunities of intervention from which it would form programs. These action areas were: Education, Culture, Health, Environment, Social Inclusion and Sustainability. The Project Advisory Board executed 5 action areas; with 11 lines of intervention, corresponding to 13 programs with 28 projects, obtaining 23 components.

The Project Advisory Board (PAB) strengthened and increased the efficiency of the communities; thereby, improving the quality of life of the people and allowing them to partake in decision-making processes. As a result, the community members are able to have greater control over their lives in the long run. Sustainable development community projects and programs are what contribute to strengthening the viability of the community in the long term.
Emotional agents - state of the art and applications
Authors: Ivanovic Mirjana , Budimac Zoran , Radovanovic Milos , Kurbalija Vladimir , Dai Weihui , Bădică Costin , Colhon Mihaela , Ninkovic Srdjan , Mitrovic Dejan
Published: November 2015

last decade, intensive research on emotional intelligence has advanced
significantly from its theoretical basis, analytical studies and processing
technology to exploratory applications in a wide range of real-life domains.
This paper brings new insights in the field of emotional, intelligent
software agents. The first part is devoted to an overview of the
state-of-the-art in emotional intelligence research with emphasis on
emotional agents. A wide range of applications in different areas like
modeling emotional agents, aspects of learning in emotional environments,
interactive emotional systems and so on are presented. After that we suggest
a systematic order of research steps with the idea of proposing an adequate
framework for several possible real-life applications of emotional agents. We
recognize that it is necessary to apply specific methods for dynamic data
analysis in order to identify and discover new knowledge from available
emotional information and data sets. The last part of the paper discusses
research activities for designing an agent-based architecture, in which
agents are capable of reasoning about and displaying some kind of emotions
based on emotions detected in human speech, as well as online documents.
Effects of remineralization procedures on shear bond strengths of brackets bonded to demineralized enamel surfaces with self-etch systems
Authors: Baka Zeliha Müge , Akin Mehmet , Ileri Zehra , Basciftci Faruk Ayhan
Published: November 2015

Objective: 

To compare the effects of different remineralization procedures on the surface roughness of teeth, shear bond strengths (SBSs), and Adhesive Remnant Index scores of self-etching primer (SEP) used to bond orthodontic brackets to previously treated demineralized enamel surfaces.

Materials and Methods: 

A total of 140 extracted human premolar teeth were randomly divided into seven equal groups. Group I was the control group. A demineralization procedure was performed in the other six groups. A remineralization procedure was performed before bonding by using casein phosphopeptide-amorphous calcium phosphate, fluoride, a microabrasion mixture (18% hydrochloric acid-fine pumice), a microabrasion agent, and resin infiltration in groups III to VII. Brackets were bonded using a self-etching primer/adhesive system. The specimens were tested for SBS. The roughness and morphology of the enamel surfaces were analyzed using profilometer and scanning electron microscopy. Data were analyzed with analysis of variance, Tukey, and G-tests at the α  =  .05 level.

Results: 

Significant differences were found in the SBS values among the seven groups (F  =  32.69, P  =  .003). The lowest SBS value was found in group II (2.62 ± 1.46 MPa). No significant differences were found between groups I, III, and VII, between groups III and IV, or between groups V and VI. The differences in the roughness values were statistically significant among the groups (P  =  .002).

Conclusions: 

Remineralization procedures restore the decreased SBS of orthodontic brackets and decrease surface roughness caused by enamel demineralization. SEPs provide clinically acceptable SBS values for bonding orthodontic brackets to previously treated demineralized enamel surfaces.
Evaluation of Force Density Levels of Light Rail Vehicles
Authors: Rajaram Shankar , Saurenman Hugh
Published: November 2015

The vibration forces generated by train wheels rolling on steel rails are characterized as the force density level (FDL). FDLs are a key component in predicting vibration levels from future train projects and generally are assumed to be independent of the measurement position and the soil properties. FDLs are dependent on several factors, which include track type, vehicle suspension systems, train speeds, and condition of wheels and rail surfaces. Presented are results of train vibration measurements at three sites in Seattle, Washington, along Sound Transit's Central Link, and a comparison of the results with previous FDL results from Central Link's start-up phase. The effects of speed, train length, and track type on FDLs were measured. A test train was employed for the measurements at three sites. The tests at the three sites also included supplemental measurements with revenue service trains. The study showed that the vibration of the current Sound Transit fleet was lower than the previous measurements apparently because the wheels were in better condition than for the earlier tests. Rail roughness was also measured at all the test sites, and their effects on FDL were explored.
Multistage Optimization of Sustainable Supply Chain of Biofuels
Authors: Huang Yongxi , Xie Fei
Published: November 2015

A sustainable biofuel supply chain must be not only economically viable but also environmentally benign. This study addressed a strategic multistage expansion (e.g., a decade) of a cellulosic biofuel supply chain system with supplements of corn grain biofuels. A multiobjective, multiyear optimization framework was proposed, and the compromise method was used to seek best-compromise solutions between economic competitiveness and environmental quality of the supply chain while satisfying evolving fuel demand, feedstock resources, and technological constraints. The model was implemented in an illustrative case study of planning an in-state ethanol supply chain in California between 2015 and 2025. The results indicated that significant trade-offs existed between cost and greenhouse gas emissions in the supply chain and that cellulosic ethanol produced from corn stover and forest residues could be an important alternative to corn ethanol with a low cost of $2.20/gal and emissions of 1.5 carbon dioxide equivalent kg/gal.
Modeling Joint Charging and Parking Choices of Electric Vehicle Drivers
Authors: Latinopoulos Charilaos , Sivakumar Aruna , Polak John W.
Published: November 2015

Electric vehicles (EVs) offer significant opportunities to improve sustainability of the road transport sector. But simultaneously, widespread adoption of EVs would create new challenges. For example, spatiotemporal concentration of charging events in high-density residential or commercial areas would place extreme demands on the power network, causing bottlenecks and grid instability. A novel approach to the typical decentralized control methods for EV charging service providers (CSPs) is presented. First, static price signals based on anticipated demand define a set of charging offers, targeted to segments of EV users. Prices are differentiated either only by time or both by time and place and allow comparison and evaluation of both scenarios. A choice-based revenue management method is employed to optimize allocation of generated charging offers, with respect to revenue outcome for the CSP. The charging coordination techniques are demonstrated through simulation. Data come from the London Travel Demand Survey and particularly trips around Westfield, one of Europe's largest urban shopping malls, representing out-of-home charging behavior for short intervals in a high-demand area. Findings suggest that in a first-come, first-served system, locational pricing might create opportunities both for increased revenue and for relocation of charging events to less-congested facilities. In the revenue management system, locational pricing significantly favors total revenue outcome but without discharging vulnerable areas. However, because agents with conflicting interests participate in the process (infrastructure owners, power system operators, EV drivers), opportunity exists for the CSP to adapt constraints according to the priority of its objectives.
Application of Work Zone Road User Costs to Determine Schedule-Related Incentives and Disincentives
Authors: Sadasivam Suri , Mallela Jagannath
Published: November 2015

Time-related contract clauses are primarily designed to encourage contractors through incentives and disincentives to complete construction projects on or ahead of schedule. Highway agencies have gained extensive experience with the application of incentives and disincentives. Agencies typically use work zone road user costs (WZRUCs) as an economic and legal basis to establish incentives and disincentives. It is common practice to estimate the value of incentives or disincentives by applying a multiplier or discount factor to a sum of the estimated WZRUCs and other owner costs. There is adequate literature available on how to estimate WZRUCs and establish incentives and disincentives; however, there is little guidance on the selection of discount factors. In addition to reemphasizing the importance of adequately compensating the contractor for accelerating construction through incentive mechanisms, this paper presents a conceptual framework for effective schedule management that incorporates the costs of construction acceleration and more-objectively estimated discount factors. This study proposes a more objective way of estimating discount factors, such as a project economics–related return on investment assessment, the project work zone disruption risk, the WZRUCs, and the owner and contractor construction engineering costs.
Performance-Based Warranty Contracts for Pavement Markings
Authors: Zlatkovic Milan , Porter Richard J. , Kergaye Cameron
Published: November 2015

In 2012, the Utah Department of Transportation (DOT) implemented a performance-based warranty on a portion of an I-15 pavement marking project. The awarded contract requested a contractor warranty on the implemented markings for a total of 6 years. This contract represented the first time that the Utah DOT had requested a warranty on pavement markings and the first time that Interstate maintenance funds had been used for them. This paper documents lessons learned from preconstruction, construction, and postconstruction phases of this project, collected through surveys of key Utah DOT personnel. The paper also includes a literature review on pavement marking warranty contracts in general, a review of the I-15 performance-based warranty contract, and reviews of previous pavement marking contracts of similar size that were based on material and workmanship warranties. Overall, the performance-based pavement marking warranty project was seen as a success. Considering that this approach to pavement marking projects is still innovative, significant potential has been shown, and state agencies should consider this direction for large-scale pavement marking projects, as well as for other construction projects in which performance can be clearly defined and measured. Because these types of Interstate freeway projects satisfy both capital improvement and preventive maintenance requirements, the projects are good candidates for FHWA support, as well as for additional funds obtained through state transportation commissions.
Sonochemical Synthesis and Characterisation of Lead Sulfide Nanoparticles Using Different Capping Agents
Authors: Bozkurt Pınar Acar , Derkuş Burak , Emregül Kaan C. , Canel Muammer
Published: November 2015

Lead sulfide (PbS) nanoparticles of about 12 nm in diameter and with a single crystalline structure have been prepared by a sonochemical method. The influence of reaction time and different capping agents such as polyethylene glycol (PEG), cetylytrimethylammonium bromide (CTAB), tetraethylortosilicate on the morphology of the synthesised PbS nanoparticles have been investigated. Results revealed polyethylene glycol (PEG) was a useful capping agent to produce PbS nanostructures with a suitable size distribution. Further studies demonstrated that by increasing the polymer chain length of PEG, the size of the PbS nanoparticles decreased remarkably. The nanoparticles were characterised by X-ray diffraction, energy dispersive X-ray spectroscopy, and transmission electron microscopy and the surface areas were determined using the BET method.
The Synthesis of 2,6-Diamino-9-ß-D-Arabinofuranosylpurine from Vidarabine by the Selective Nitration and Ammonolysis
Authors: Xia Ran , Sun Li-Ping , Yang Xi-Ning , Qu Gui-Rong
Published: November 2015

A practical synthesis of 2,6-diamino-9-β-D-arabinofuranosylpurine from the commercially available vidarabine is reported. Treatment of fully protected vidarabine with 2,2,2-trifluoroacetic anhydride and tetrabutylammonium nitrate introduced a –NO2 group in the C2 position in high yield. 2,6-Diamino-9-β-D-arabinofuranosylpurine was synthesised in three steps and 61% total yield after ammonolysis of the –NO2 accompanied by removal of the benzoyl groups.
Efficient Green Synthesis of N′-Benzylidene-2-(2-Fluorobiphenyl) Propanehydrazides: Crystal Structure and Anti-Oxidant Potential
Authors: Zaheer Muhammad , Zia-ur-Rehman Muhammad , Jamil Nadia , Arshad Muhammad Nadeem , Siddiqui Sabahat Zahra , Asiri Abdullah Mohammad
Published: November 2015

For the synthesis of N′-benzylidene-2-(2-fluorobiphenyl)propanehydrazides, 2-(2-fluorobiphenyl-4-yl)propanoic acid was esterified to methyl 2-(2-fluorobiphenyl-4-yl)propanoate under microwave irradiation followed by hydrazinolysis. This hydrazide was then reacted in an ultrasonic bath with different benzaldehydes to afford a series of N′-benzylidene-2-(2-fluorobiphenyl)propanehydrazides. Comparison of both the conventional and ultrasound assisted reactions indicates a significant reduction in reaction times and improvement in yields. Besides chemical characterisation and X-ray crystallography, all the synthesised compounds were evaluated for their anti-oxidant potential (total anti-oxidant activity, ferric reducing antioxidant power and total phenolic content) and most of them were found to have useful potential for pharmaceutical applications especially derivative bearing 2-hydroxy substituents.
Do Not Just Do as I Do: Knowledge and Learning in the Image of Thought
Authors: Posteraro Tano S.
Published: November 2015

What does it mean for philosophy to take seriously the chaos that haunts and threatens to undermine the fleetingly static formations that populate our epistemological landscapes? What does it mean to learn, think and know on a plane detached from transcendent truths, from recognition and representation, from the inverted image of falsity? We risk badly mangling our answers to these questions so long as we take for granted the orthodoxal image of thought and its conservative postulates. But critique is not enough, we need reconception, creativity; we need thought. This paper locates in Deleuze's ‘Image of Thought’ precisely these resources in the form of a philosophy of learning, taking as its guiding light the claim that learning ought no longer to name a merely transitory movement between a lack of knowledge and its fulfilment in the apprehension of truth, but the domain from which the transcendental conditions of thought itself are to be drawn.
Biological Control of Spreading Dayflower (Commelina diffusa) with the Fungal Pathogen Phoma commelinicola
Authors: Boyette Clyde , Hoagland Robert , Stetina Kenneth
Published: November 2015

Greenhouse and field experiments showed that conidia of the fungal pathogen, Phoma commelinicola, exhibited bioherbicidal activity against spreading dayflower (Commelina diffusa) seedlings when applied at concentrations of 106 to 109 conidia·mL−1. Greenhouse tests determined an optimal temperature for conidial germination of 25 °C–30 °C, and that sporulation occurred on several solid growth media. A dew period of ≥ 12 h was required to achieve 60% control of cotyledonary-first leaf growth stage seedlings when applications of 108 conidia·mL−1 were applied. Maximal control (80%) required longer dew periods (21 h) and 90% plant dry weight reduction occurred at this dew period duration. More efficacious control occurred on younger plants (cotyledonary-first leaf growth stage) than older, larger plants. Mortality and dry weight reduction values in field experiments were ~70% and >80%, respectively, when cotyledonary-third leaf growth stage seedlings were sprayed with 108 or 109 conidia·mL−1. These results indicate that this fungus has potential as a biological control agent for controlling this problematic weed that is tolerant to the herbicide glyphosate.
Indoor Air Quality in Naturally Ventilated Italian Classrooms
Authors: Fuoco Fernanda , Stabile Luca , Buonanno Giorgio , Trassiera Concepcion , Massimo Angelamaria , Russi Aldo , Mazaheri Mandana , Morawska Lidia , Andrade Alexandro
Published: November 2015

Characterization of indoor air quality in school classrooms is crucial to children’s health and performance. The present study was undertaken to characterize the indoor air quality in six naturally ventilated classrooms of three schools in Cassino (Italy). Indoor particle number, mass, black carbon, CO2 and radon concentrations, as well as outdoor particle number were measured within school hours during the winter and spring season. The study found the concentrations of indoor particle number were influenced by the concentrations in the outdoors; highest BC values were detected in classrooms during peak traffic time. The effect of different seasons’ airing mode on the indoor air quality was also detected. The ratio between indoor and outdoor particles was of 0.85 ± 0.10 in winter, under airing conditions of short opening window periods, and 1.00 ± 0.15 in spring when the windows were opened for longer periods. This was associated to a higher degree of penetration of outdoor particles due to longer period of window opening. Lower CO2 levels were found in classrooms in spring (908 ppm) than in winter (2206 ppm). Additionally, a greater reduction in radon concentrations was found in spring. In addition, high PM10 levels were found in classrooms during break time due to re-suspension of coarse particles.