bluuebunny/crossref_metadata_2025 huggingface dataset:
Collagen Membrane Barrier Therapy to Guide Regeneration in Class II Furcations in Humans
Authors: Van Swol Ronald L. , Ellinger Royal , Pfeifer John , Barton Nancy E. , Blumenthal Neil
Published: March 2012

This study was undertaken to evaluate the effectiveness of resorbable collagen membranes in guided tissue regeneration. The study participants were 38 adults with moderate to advanced periodontitis. Each patient had at least one Class II furcation defect which could serve as either a test or control tooth. The cases were randomized prior to selection, so that investigators did not know whether the patient would be a test case or a control case until the time of surgery. Sites were surgically exposed and measurements were recorded from the cemento‐enamel junction (CEJ) directly coronal to the furcation area to the alveolar crest, and to the base of the defect. Horizontal furcation measurements were also made, using a color coded furcation probe. The test patients had a trimmed and shaped collagen membrane barrier placed over the prepared furcation area. The control patients received the identical surgical management, except that no collagen membrane barrier was placed. All patients received normal post‐surgical care, and at 12 weeks post‐surgery, were scheduled for re‐entry surgery. The re‐entry mucoperiosteal flaps were designed to expose the furcation area for measurements, as described above. There was clinical improvement in all measurements made in both the test and control patients over the 3‐month period. The horizontal furcation measurement and the CEJ to base of alveolar defect measurements did yield a statistically significant improvement when comparing the test patients to the controls. J Periodontol 1993; 64:622–629
Oral‐Dental Findings in a Case of Maffucci's Syndrome
Authors: Yavuzyilmaz Ezel , Yamalik Nermin , Eratalay Kenan , Atakan Nilgün
Published: March 2012

A case of Maffucci's syndrome (MS) in a 17‐year‐old Caucasian female is presented with a thorough intraoral examination. The prominent finding was recurrent gingival hyperplasia affecting both the free and attached gingiva with deep periodontal pockets, tooth mobility, pathological tooth migration, and severe alveolar bone loss. Furthermore, the pattern of alveolar bone destruction, in many ways, resembled that of localized juvenile periodontitis. Although there is always the possibility that these oral features may not be related with the syndrome, we suggest a careful dental and periodontal examination in future cases, which we believe will help develop a better description of oral findings in MS. J Periodontol 1993;64:673–677.
Long‐Term Periodontal Care: A Comparative Retrospective Survey
Authors: Pearlman Braham A.
Published: March 2012

The maintenance of 172 patients who were treated and then attended a periodontal practice in Sydney, Australia for periods of at least 10 years has been surveyed. The results, expressed as loss of teeth over the maintenance period, have been compared with a 1978 study. Results of the two surveys have been compared for total tooth loss over the maintenance period, loss of individual tooth types, loss of teeth with furca lesions, and tooth loss relative to surgical experience. The comparative analysis is limited by the difference in total number of patients and by the duration of the studies. The proportionate division of patients into three groups according to tooth retention (well maintained, downhill, and extreme downhill) was statistically similar in both surveys. There were very few statistically valid differences in numbers of individual teeth lost between the two studies. Despite these comparable end results of long‐term maintenance, the surgical experience was quite different, with the patients in our practice undergoing much more surgical treatment than those in the earlier report. The results appear to support the hypothesis that long‐term maintenance is attainable for most periodontal patients, and is consistent with a variety of treatment approaches. J Periodontol 1993; 64:723–729.
Periodontal Therapy: Prospects for the Future
Authors: Page Roy C.
Published: March 2012

Prior to the 1950s, periodontitis was treated mostly by tooth exfoliation or extraction, and that is still the predominant treatment for most of the world's populations today. Debridement of the root surface by scaling and root planing came into relatively common use in the first half of the present century and has become the central feature held in common by all currently‐used forms of periodontal therapy. Until the 1980s, the most commonly‐used treatment consisted of scaling and root planing, followed by resective surgery aimed at achieving zero pocket depth. During the 1980s, data were obtained demonstrating that the thoroughness of root debridement and subgingival infection control, not the presence or absence or periodontal pockets, is the major determinant of successful periodontal therapy, and non‐surgical therapy became a commonlyused treatment. Neither resective surgery nor non‐surgical therapy results in significant regeneration of periodontal attachment. With the realization that periodontitis is an infectious process, the use of antibiotics and other anti‐infective agents came into common use as adjuncts to other standard therapies. An understanding of the pathways by which the soft and calcified tissues of the periodontium are destroyed has led to the likelihood of widespread future use of the non‐steroidal, anti‐inflammatory family of drugs to suppress alveolar bone destruction by blocking prostaglandin production, and to the use of chemically‐modified tetracyclines that chelate divalent cations and thereby block tissue destruction by the metalloproteinases. Recent data clearly show that regeneration of the previously‐destroyed periodontal attachment tissues is biologically possible, and regeneration has become the goal of therapy for the 1990s. Use of osteoconductive and osteoinductive graft materials can, under favorable conditions, induce roughly 60% to 70% regeneration of bone lesion height or volume with concomitant improvement in the clinical conditions. Regeneration by grafting may be further enhanced by use of barrier membranes that exclude gingival fibroblasts and epithelium from the healing site. Still further enhancement seems to be possible by local application of various growth factors, although studies in this important area are now only in their infancy. The future of periodontal therapy is exceedingly bright. It seems likely that we may be able to achieve nearly complete regeneration of periodontal attachment at many, although not all, sites through the use of root debridement and anti‐infective and anti‐inflammatory drugs and agents that inhibit metalloproteinases to arrest progress of disease and resolve the inflammatory process, followed by the combined use of graft material, barrier membranes, and growth factors to induce regeneration of periodontal attachment tissues. J Periodontol 1993; 64:744–753.
Underbalanced Drilling Expert System Development
Authors: Al-yami Abdullah S. , Schubert Jerome
Published: March 2012

One way to mitigate formation damage is to design and execute underbalanced drilling in all phases of operations such as drilling, tripping and completion. Field cases of underbalanced drilling failure showed high formation damage which motivated the need of expert systems in underbalanced drilling to achieve higher production rates.

Many underbalanced drilling operations have been analyzed, resulting in the optimum practices, as outlined in this paper. To the best of the authors' knowledge, there are no systematic guidelines for underbalanced drilling.

The objective of this paper is to propose a set of guidelines for the optimal underbalanced drilling operations, by integrating current best practices through a decision-making system based on Artificial Bayesian Intelligence. Optimum underbalanced drilling practices collected from data, models, and experts' opinions, are integrated into a Bayesian Network BN to simulate likely scenarios of its use that will honor efficient practices when dictated by varying certain parameters.

The proposed decision-making model follows a causal and an uncertainty-based approach capable of simulating realistic conditions on the use of underbalanced drilling operations. For instance, by varying the type of UBD (flow, aerated, etc), operation and formation properties the system will show optimum tripping and connection procedure. The developed model also acknowledged UBD drilling techniques in different scenarios such as fractured formations, low permeability and high permeability formations.

The model also shows optimum solutions to problems related to underbalance drilling such as well control, completion, drilling multiple reservoirs with different pressures, equipment associated with drilling.

The advantage of the artificial Bayesian intelligence method is that it can be updated easily when dealing with different opinions.
Computational Optimization of Shale Resource Development using Reduced-Physics Surrogate Models
Authors: Wilson K. C. , Durlofsky L. J.
Published: March 2012

The economics of oil and gas field development can be improved significantly by using computational optimization to guide operations. In this work, we present a general work flow for applying optimization to the development of shale gas reservoirs. Starting with a detailed full-physics simulation model, which includes highly-resolved fracture networks, dual-porosity, dual-permeability regions, and gas desorption, the approach first entails the generation of a much simpler, and much more computationally efficient, reduced-physics surrogate model. The reduced-physics model is tuned using a history-matching procedure to provide results in close agreement with the full-physics model for a variety of field development scenarios. The surrogate model is then used for optimization. In the optimizations considered here, we apply a direct search technique (generalized pattern search) and seek to determine the optimal locations, lengths, and number of fracture stages for a set of horizontal wells. In two examples, involving two- dimensional models with properties representative of the Barnett Shale, optimization is shown to provide field development scenarios with net present values that are more than double those of base case designs. Finally, it is possible that the reduced-physics surrogate-modeling approach presented here could find use in other applications, such as uncertainty quantification.
A Selection Criterion for CO2-Enhanced Oil Recovery and Dispersion Modeling of High-Pressure CO2 Release
Authors: Aladasani Ahmad , Bai Baojun , Nygaard Runar
Published: March 2012

The use of miscible carbon dioxide (CO2) flooding has increased significantly in the past decade. What makes CO2 unique is its low miscibility pressure, which extends the candidacy of CO2 to reservoirs with lower API gravity, shallower depths and lower fracture pressure gradients compared to reservoirs in which miscible nitrogen or miscible hydrocarbon flooding might be used. Furthermore, the financial incentives associated with the removal of a greenhouse gas offset development costs and operating expenditures. Therefore, this paper focuses primarily on selection criteria for CO2 Enhanced Oil Recovery (EOR) and the dispersion modeling of high-pressure CO2 release, as these are critical in offsetting capital investments and managing legal liabilities.

The available EOR selection criteria, which are based on reported EOR projects were developed initially by Taber in 1983 and then updated by Taber et al. in 1996 and again by Aladasani & Bai in 2010. Recent publications by Aladasani & Bai (2011) regarding discussions surrounding EOR selection criteria focus on dataset distribution to refine EOR candidacy selection. The work presented in this paper further develops the tools with which to screen miscible CO2 for EOR applications by offering detailed distributions and correlations of reservoir properties reported in miscible CO2 projects, as well as a prediction model for miscible CO2 recovery. The screening tools presented in this paper are intended as a new detailed and systematic approach to selecting miscible CO2 flooding and to developing EOR as a whole.

The increase in Carbon Sequestration Projects (CSP) and CO2 EOR projects has resulted in the expansion of the CO2 pipeline network in the United States (US). An overview of the CO2 network in the US, the transit pipeline incident history in North America and Europe, and the scope of pipeline risk studies are presented. Finally, recent developments in CO2 consequence modeling inform the dispersion modeling of critical CO2 releases, highlighting the toxicity risk of H2S in anthropogenic CO2 streams.
Sensitivity Analysis for Joint Inversion of Production and Time-lapse Seismic Data of Norne Field
Authors: Suman Amit , Mukerji Tapan
Published: March 2012

Dynamic data, including production and time lapse seismic can be used in history matching process for better description of the reservoir and thus for better reservoir forecasting. However joint inversion of time lapse seismic and production data is complex and challenging with uncertainties at each step of the process. So it is essential, before proceeding with large scale history matching, to investigate parameter sensitivity for both types of data. In this study the data set of Norne field is used to find out which reservoir rock and fluid parameters have the most impact on time lapse seismic and production data at this field. The result of this study will be used in history matching of time lapse seismic and production data of Norne field.
Enhancing Steamflood Performance of Highly Permeable Dipping Reservoir with Strong Waterdrive
Authors: Chenot David W. , Shah Rusheet D.
Published: March 2012

Placement and timing of steam injectors is critical for optimal performance of the Steamflood at Round Mountain Oilfield; a dipping, highly permeable reservoir with a very strong water drive. Diligent reservoir management to conserve steam is a necessity in any steamflood, especially if a strong water drive is present.

In the Round Mountain Field, with primary water cuts of 99.5%, steam injection was instituted at an up structure position (Row 0) in 1998. Water was produced with high volume lift electric submersible pumps (ESPs) in wells two rows down structure (Rows 1 & 2) from the injectors. These down structure wells intercepted encroaching aquifer and reduced reservoir pressure; imperative for steam front expansion. As the steam front advanced, wells that were formerly water intercept wells (Row 1) began to heat up and produce oil at low water cuts. These wells were placed on beam units, and new water intercept wells (Row 3) were drilled one row further down structure.

Heat losses to Overburden, Underburden, and by hot fluid withdrawal over time decreased the rate of steam front expansion. This paper discusses the "Steam Injector Relocation" strategy devised to specifically tackle the problem. By this strategy, once the down structure row of producers (Rows 2 & 3) experience slower steam front expansion and the up structure wells decline in production, the up structure row (Row 1) is converted to injection. This leads to a more favorable expansion of steam front, significant improvement of production, and lower heat losses. This process has been repeated four times, and at present the steam front is approaching the original oil water contact in some areas of the field.

The lessons learned from this project emphasize the need for careful and continuous surveillance of production, pressure, flow line temperatures, and heat losses in order to move both injectors and producers at critical times.
Solar-Generated Steam for Oil Recovery: Reservoir Simulation, Economic Analysis, and Life Cycle Assessment
Authors: Sandler Joel , Fowler Garrett , Cheng Kris , Kovscek Anthony
Published: March 2012

Integrated solar thermal steam generation and heavy-oil recovery projects have garnered interest because of their ability to decrease the variability of steam generation costs arising from fluctuations in natural gas prices as well as life-cycle carbon dioxide emissions. The viability of a solar thermal steam generation system (with and without natural gas back-up) for thermal enhanced oil recovery (TEOR) in heavy-oil sands was evaluated in this study. Using the San Joaquin Valley as a case study, the effectiveness of solar TEOR was quantified through reservoir simulation, economic analysis, and life-cycle assessment of oil-recovery operations. Reservoir simulation runs with continuous but variable rate steam injection were compared with a base-case Tulare Sand steamflood project. Reservoir properties and well geometries were drawn from the literature. For equivalent average injection rates, comparable breakthrough times and recovery factors of 65% of the original oil in place were predicted, in agreement with simulations in the literature. Daily cyclic fluctuations in steam injection rate do not greatly impact recovery for this reservoir setting. Oil production rates for a system without natural gas back-up to moderate injection rates do, however, show seasonal variation. Economic viability was established using a discounted cash flow model incorporating historical prices and injection/production volumes from the Kern River oil field. This model assumes that present day steam generation technologies could be implemented fully at TEOR startup for Kern River in 1980, for the sake of comparison against conventional steam generators and cogenerators. All natural gas cogeneration and 100% solar fraction scenarios had the largest and nearly equal net present values (NPV) of $12.54 B and $12.55 B, respectively, with production data from 1984 to 2011. Solar fraction refers to the steam provided by solar steam generation. Given its large capital cost, the 100% solar case shows the greatest sensitivity to discount rate and no sensitivity to natural gas price because it is independent of natural gas. Because there are very little emissions associated with day-to-day operations from the solar thermal system, life-cycle emissions for the solar thermal system are significantly lower than conventional systems even when the embodied energy of the structure is considered. Here, we estimate that less than 1 g of CO2/MJ of refined gasoline results from the TEOR stage of production if solar energy provides all steam. By this assessment, solar thermal based or supplemented steam generation systems for TEOR appear to be a preferred alternative, or supplement, to fully conventional systems using natural gas (or higher carbon content fuels), especially in areas with large solar insolation.
Investigation of Recovery Mechanism of Steam Injection in Heavy Oil Carbonate Reservoir and Mineral Dissolution
Authors: Tang Guo-Qing , Inouye Art , Lee Vincent , Lowry Dustin , Wei Wei
Published: March 2012

Steam injection in carbonate heavy oil reservoirs is a complex process. The main challenge is that the injected steam breaks through from a fracture network resulting in poor sweep efficiency. A large amount of oil remains behind the steam front. In addition, severe mineral dissolution (or precipitation) due to steam/brine/rock interaction occurred at high temperature has a significant impact on steam injectivity and recovery mechanism.

This paper presents an extensive lab study focused on understanding the recovery mechanism and relevant mineral dissolution. Around 10 reservoir cores and crude oil sample with an API gravity of 14 were used for this study. Imbibition, steam flooding, and pressure blow-down tests were conducted. The results show that the recovery mechanism of steam injection in the target carbonate reservoir is composed of imbibition, viscosity reduction, in-situ steam generation induced by pressure blow-down, and oil expansion mechanisms with different contributions. As the rock is heated to near 400°F, imbibition becomes the dominant recovery mechanism. The increased imbibition recovery is strongly dependent on mineral dissolution at a high temperature, which results in wettability alteration towards strong water-wetness. Due to the presence of micro-fractures, steam drive is less efficient compared to imbibition. In-situ steam generation can still increase oil recovery by an additional 17-32% (OOIP) following steamflood displacement at residual oil saturation.

Significant mineral dissolution is observed with high resolution CT scanning and effluent geochemical analysis. CT-image analysis shows the size of vugs is increased 2-5 times due to mineral dissolution. ICP (Inductivity Coupled Plasma) and IC (Ion Chromatogragh) analysis shows that carbonate is the main dissolved mineral. Mineral dissolution does not increase the effective permeability because these vugs are mainly connected by micro fractures where mineral dissolution effects are negligible. In fact, permeability is reduced due to fines migration resulted by mineral dissolution.
Optimization of Core-Log Derived Permeability Using Pressure Transient Analysis in Low-Permeability Waterflood: Ventura Avenue Field Case Study
Authors: Albornoz Fernando , Williams Steve O.
Published: March 2012

A key to effective reservoir characterization lies primarily in obtaining good estimates of permeability. Permeability estimation through the integration of core, wireline and well test data has gained significant attention in recent years. However, these efforts are masked by vague implementation processes arising from calibration and scaling issues. This paper presents a systematic and unique approach for estimating permeability from the integration of core, wireline and pressure transient analysis data and prudently demonstrates the optimization and implementation techniques necessary for scaling the core-log derived (small scale) absolute permeability to the effective permeability data derived from pressure transient analysis (large scale).

This unique approach was accomplished by first integrating reservoir conditioned core data with wireline logs for zonation of reservoirs into flow units. Core derived Flow Zone Indicator (FZI), which is a function of the reservoir quality index (RQI) and normalized porosity (PHIZ), was used as a predictor variable in modeling the selected wireline log responses using an adaptive neuro-fuzzy logic inference system (ANFIS).

Predicted FZI and resultant core-log derived permeability were then calibrated using a water-oil relative permeability model derived from a suite of special cores from the same flow zones. Core-log derived permeability was then fine-tuned with the pressure transient analysis in the same reservoirs of interest.

The results of this study have provided valuable answers to water injectivity predictions in the thick and thinly bedded sand/shale sequence of the Ventura Avenue Field. Water injection profiles in these reservoirs are now better understood and, consequently, the reservoirs are better characterized for waterflood recovery optimization.
Uncertainty Analysis of a CO2 Sequestration Project Using Surrogate Reservoir Modeling Technique
Authors: Amini Shohreh , Mohaghegh Shahab , Gaskari Razi , Bromhal Grant
Published: March 2012

While CO2 Capture and Sequestration (CCS) is considered a part of the solution to overcoming the ever increasing level of CO2 in the atmosphere, one must be sure that significant new hazards are not created by the CO2 injection process. The risks involved in different stages of a CO2 sequestration project are related to geological and operational uncertainties. This paper presents the application of a grid-based Surrogate Reservoir Model (SRM) to a real case CO2 sequestration project in which CO2 were injected into a depleted gas reservoir. An SRM is a customized model that accurately mimics reservoir simulation behavior by using Artificial Intelligence & Data Mining techniques. Initial steps for developing the SRM included constructing a reservoir simulation model with a commercial software, history matching the model with available field data and then running the model under different operational scenarios or/and different geological realizations. The process was followed by extracting some static and dynamic data from a handful of simulation runs to construct a spatio-temporal database that is representative of the process being modeled. Finally, the SRM was trained, calibrated, and validated.

The most widely used Quantitative Risk Analysis (QRA) techniques, such as Monte Carlo simulation, require thousands of simulation runs to effectively perform the uncertainty analysis and subsequently risk assessment of a project. Performing a comprehensive risk analysis that requires several thousands of simulation runs becomes impractical when the time required for a single simulation run (especially in a geologically complex reservoir) exceeds only a few minutes. Making use of surrogate reservoir models (SRMs) can make this process practical since SRM runs can be performed in minutes.

Using this Surrogate Reservoir Model enables us to predict the pressure and CO2 distribution throughout the reservoir with a reasonable accuracy in seconds. Consequently, application of SRM in analyzing the uncertainty associated with reservoir characteristics and operational constraints of the CO2 sequestration project is presented.
Application of Well-Based Surrogate Reservoir Models (SRMs) to Two Offshore Fields in Saudi Arabia, Case Study
Authors: Mohaghegh Shahab D. , Liu Jim , Gaskari Razi , Maysami Mohammad , Olukoko Olugbenga
Published: March 2012

Well-based Surrogate Reservoir Model (SRM) may be classified as a new technology for building proxy models that represent large, complex numerical reservoir simulation models. The well-based SRM has several advantages over traditional proxy models, such as response surfaces or reduced models. These advantages include (1) to develop an SRM one does not need to approximate the existing simulation model, (2) the number of simulation runs required for the development of an SRM is at least an order of magnitude less than traditional proxy models, and (3) above and beyond representing the pressure and production profiles at each well individually, SRM can replicate, with high accuracy, the pressure and saturation changes at each grid block.

Well-based SRM is based on the pattern recognition capabilities of artificial intelligence and data mining (AI&DM) that is also referred to as predictive analytics. During the development process the SRM is trained to learn the principles of fluid flow through porous media as applied to the complexities of the reservoir being modeled. The numerical reservoir simulation model is used for two purposes: (1) to teach the SRM the physics of fluid flow through porous media as applied to the specific reservoir that is being modeled, and (2) to teach the SRM the complexities of the heterogeneous reservoir represented by the geological model and its impact on the fluid production and pressure changes in the reservoir.

Application of well-based SRM to two offshore fields in Saudi Arabia is demonstrated. The simulation model of these fields includes millions of grid blocks and tens of producing and injection wells. There are four producing layers in these assets that are contributing to production. In this paper we provide the details that is involved in development of the SRM and show the result of matching the production from the all the wells. We also present the validation of the SRM through matching the results of blind simulation runs.

The steps in the development of the SRM includes design of the required simulation runs (usually less than 20 simulation runs are sufficient), identifying the key performance indicators that control the pressure and production in the model, identification of input parameters for the SRM, training and calibration of the SRM and finally validation of the SRM using blind simulation runs.
Uncertainty Analysis on In-Situ Combustion Simulations Using Experimental Design
Authors: Ogunbanwo Olufolake , Gerritsen Margot , Kovscek Anthony R
Published: March 2012

Experimental design is a widely used statistical method for understanding the factors that impact an information gathering exercise such as mechanistic simulations. It is used here to gain insight into flow and operating conditions that affect in-situ combustion. Specifically, experimental design was applied to understand in-situ combustion of very heavy oil using a commercial thermal simulator. The design parameters investigated were selected based on combustion laboratory results and literature. These included activation energies of the reaction schemes, oil saturation, air injection rate and pressure control at the producer. A full factorial design was used to create the parametric space considering interactions between the parameters. The degree to which the combustion peak temperature, pressure, combustion front speed, recovery efficiency and coke deposited changed was used to determine the most critical parameters. Results showed the activation energy of the coke deposition reaction had the greatest influence on the combustion process. For the 3-reaction pathway assumed for crude-oil combustion, a slight increase in this activation energy inhibited the combustion reactions. The injection pressure of the system was impacted significantly by the initial oil saturation while the speed at which the front propagated was shown to be primarily a function of the air injection rate. Results also showed that for a given initial oil saturation, a limiting air flux existed below which oil plugging of the linear system occured. Given successful ignition and propagation of the front, optimal recovery was obtained between initial oil saturations of 45-70%. We also observed interaction between the parameters. The effect of the activation energy of the combustion reaction on the recovery was strongly dependent on the amount of oil initially in place. Recovery decreased with increasing activation energy at lower initial saturations, but was independent of activation energy at greater initial saturations. In addition, the velocity profile showed different incremental oil recovery rates with different initial oil saturation.
Production Performance of Multiply Fractured Horizontal Wells
Authors: Belyadi A. , Aminian K. , Ameri S.
Published: March 2012

The objective of this study was to conduct a modeling study to determine the production performance of multiply fractured horizontal well completed in Shale formations and to investigate the impact of hydraulic fractures on the production performance of horizontal wells in ultra-low permeability formations. A commercial reservoir simulator was utilized to model both single and a dual porosity reservoir since both hydraulic fractures and natural fractures play significant roles in well performance of the low permeability reservoirs. The adsorbed gas component was also included in the models. The single and a dual porosity models were utilized to investigate the flow regimes for horizontal wells with multi-stages of hydraulic fracturing stimulation. History matching with actual production from Marcellus Shale wells was utilized to determine the basic model parameters. The results indicated the presence of number of different flow regimes. The hydraulic fractures appear to dominate the early production performance. The impact of reservoir and hydraulic fracture parameters on the flow regimes as well as the production performance and gas desorption were also investigated. The results can be utilized to investigate the feasibility horizontal wells with multiple hydraulic fractures and optimize the production from the shale formations.
The Polluter Pays Principle as a policy tool in an externality model for nitrogen fertilizer pollution
Authors: Fishman Yaron , Becker Nir , Shechter Mordechai
Published: March 2012

A policy based on the Polluter Pays Principle (PPP) with respect to the subject of contamination by nitrogen fertilizer is proposed. The mechanism is tested via a cost-efficient input tax policy to supply clean drinking water that is subject to contamination by nitrogen fertilizer and to quantify the welfare change due to public control. The paper proposes, for different water scarcity conditions, a policy that supports the legal principle of the PPP, by compensating the victim for the residual pollution not abated by the cost efficient solution, without any effects on the efficiency criterion. By introducing a Welfare Change Index (WCI) which measures the significance of an authority's intervention in dealing with externalities, we suggest that for relatively high and moderate water scarcity conditions, welfare change supports public intervention. However, for low scarcity conditions, welfare change is low, which discourages public intervention.
The process of innovation during transition to a water saving society in China
Authors: Xia Chun , Pahl-Wostl Claudia
Published: March 2012

To achieve an efficient use and allocation of limited water resources and thus resolve increasing water use conflicts due to fast rising societal water demands, in 2000, the Chinese government started a management strategy of ‘Construction of a Water Saving Society (WSS)’. It is guided by the principle that socio-economic development should consider the carrying capacity of the ecosystem and focuses on institutional innovation, building on the water rights concept. This paper explores the innovation process during the transition towards WSS by investigating the development course of the innovation process during the transition towards WSS, and the adaptive capacity of the existing water management regime underlying the innovation process. Accordingly, an analysis framework consisting of three types of governance activities and factors determining a regime's adaptive capacity was developed, based on the theory of transition management and adaptive governance. The Tianjin and Zhangye WSS experiments were selected for a deep understanding of local innovations. It is revealed that co-evolution of all three types of governance activities that are claimed to be essential for transition has taken place. However, the current adaptive capacity of the regime still needs further enhancement to support the transition towards the desired WSS in China. Finally, some general insights are provided for policy innovations in other political economies.
The Development of an Instrument to Assess Preservice Teacher's Technological Pedagogical Content Knowledge
Authors: Lux Nicholas J. , Bangert Arthur W. , Whittier David B.
Published: March 2012

The purpose of this study was to develop and validate the Pre-service Teacher-Technological Pedagogical Content Knowledge Survey (PT-TPACK) instrument. The PT-TPACK survey items were written to assess preservice teachers' perceptions and understanding of the Technological Pedagogical Content Knowledge construct originally proposed by Mishra and Koehler (2006). The participants for this study were preservice teachers ( n = 120) enrolled in a foundations of educational technology course at a mid-sized western university. Data analysis yielded six interpretable factors: pedagogical knowledge (PK), technological knowledge (TK), content knowledge (CK), pedagogical content knowledge (PCK), technological pedagogical knowledge (TPK), and technological pedagogical content knowledge (TPACK). Technological content knowledge (TCK) was the only dimension in the TPACK construct specified a priori that did not emerge. Results from this study suggest that the PT-TPACK survey holds promise as a useful evaluation tool for assessing preservice teachers' knowledge and use of technology to increase the effectiveness of their instructional efforts.
Effect of Hydrogen Peroxide at 35% on the Morphology of Enamel and Interference in the De-remineralization Process: An In Situ Study
Authors: de Arruda AM , Santos PH dos , Sundfeld RH , Berger SB , Briso ALF
Published: March 2012

This study evaluated the microhardness and histomorphology of bovine enamel when 35% hydrogen peroxide is used. A total of 44 specimens were adapted to removable devices used by 11 individuals subjected to dental caries challenge. A decrease in microhardness was observed for all groups after the cariogenic challenge. Microscopic analysis revealed that fragments subjected to cariogenic challenge associated with bleaching had more intense superficial histologic changes, but the depth of the lesions remained unchanged. It was concluded that 35% hydrogen peroxide enhanced the reduction in hardness and histomorphologic changes in the enamel surface exposed to cariogenic challenge.
The Regulation of Ventilation by Changing the Operation of the Main Fan and its Impact on the Face Worked Under the Main Haulage Level / Regulace Větrání Změnou Provozu Hlavního Ventilátoru A Její Dopad Na Podpatrově Dobývaný Porub
Authors: Zapletal Pavel , Prokop Pavel , Dorazil Václav
Published: March 2012

The regulation of mine ventilation by changing the operation of the main fan (HV) has both positive and negative aspects. One of the positive aspects is that this regulation can be made directly on the mine surface without lowering into the mine, namely by turning the fan blades from the minimum to maximum position. This regulation can be performed either from the control room or directly at the fan.

The utilization of this control method in the mine ventilation (the reducing or increasing of the depression of main fans) brings with also certain disadvantages. By the overall regulation of the depression of main fans we influence the overall mine ventilation network. The HV regulation can without further interventions cause problems in other part of the mine. Therefore, to eliminate the negative effects we have to do partial steps in the regulation of ventilation in the ventilation network to achieve the desired effect in a specific part of the mining field and prevent the unwanted effect in other parts of the ventilation network. In this article we deal with the negative effects on a face worked under the main haulage level
The Future of Blue Economy: Lessons for European Union
Authors: Kaczynski Wlodzimierz
Published: March 2012

The Future of Blue Economy: Lessons for European Union

Advancing global economic integration through the oceans, an interplay of economic, social, climatologic and technical forces are bringing the oceans to the forefront of resource development and business activity. With oceans covering over 70 percent of the Earth's surface, the future of the ocean space is increasingly being shaped by the interaction of numerous and powerful forces, most important of them being human activities. Over next 20 years, increasing uncertainty will be generated by the confluence of rapid social, cultural, technological and geopolitical changes. The rapid global increase in the production outputs of industry, agriculture and fisheries, as well as rising levels of consumption of marine products and the demand for coastal space worldwide is exerting increasing environmental pressure on the ocean. There is a need to identify more effective means to reduce the environmental impacts generated by the economic growth and its by-products. Sustainable approaches meet the needs of present without compromising the ability of future generations to satisfy their own needs. The Blue Economy concept is about the commercial development of oceans in a sustainable way. Poland's future economic security is linked with country's presence in the world ocean and successful membership in international bodies such as European Union, NATO and various United Nations maritime organizations. These factors will also determine Poland's place and its role in the global ocean economy.
The Development of Production Management Concepts
Authors: Kosieradzka Anna , Kąkol Urszula , Krupa Anna
Published: March 2012

The Development of Production Management Concepts

The aim of this paper is the analysis of contemporary concepts used in production management in relation to the paradigms which accompanied their appearance and development. The first chapter contains a definition of the term 'paradigm', discusses the importance of the paradigms for the development of a scientific approach to management and lists examples of paradigms relevant to production management. In the second chapter such management concepts as LM, Kaizen, TOC, TQM, TPM, Six Sigma and BPR are presented, along with their respective old and new paradigms, main goals, fundamental rules and tools (methods and techniques). Some less popular concepts are also dealt with. The last chapter is devoted to an analysis of interactions between the analyzed concepts, with an emphasis on their mutual compatibility and complementarity, which can be of benefit in the process of their implementation.
Loyalty Programs Effectiveness
Authors: Szczepańska Katarzyna , Gawron Patryk
Published: March 2012

Loyalty Programs Effectiveness

An increasing number of loyalty programs is one of the most common phenomena observed in the practice of marketing companies on the market today. Objectives and tasks of loyalty programs determine the type of use of marketing instruments affecting the attitudes and behaviours of customers, which is aimed at the program. The diversity of factors influencing the effectiveness of loyalty programs should set the scope and object of empirical research. As the results of studies to evaluate the effectiveness of loyalty programs mainly on the B2C market is diverse in terms of the criteria. This article presents the essence of loyalty programs and the factors influencing their effectiveness.
Capacity Evaluation of Roundabouts in Slovakia
Authors: Gavulová Andrea , Drličiak Marek
Published: March 2012

Capacity Evaluation of Roundabouts in Slovakia

Two technical regulations for capacity estimation of roundabouts are valid in the Slovak Republic at the present time. Each of these regulations is based on a different theory of capacity estimation which affects the outcome of the capacity of roundabouts and their evaluation. The capacity of various roundabouts was estimated according to both methods in the previous analysis made at our department [3] and in some cases different results of the evaluation were achieved. The question is: which one of the mentioned theories better reflects a real capacity of the roundabout? For this reason some of the existing roundabouts in the town Žilina were selected and they were evaluated according to both methods and a micro simulation using PTV Vissim software. The geometrical parameters of roundabout, real driving behaviour (speed, proportions, acceleration, etc.) and also pedestrian behaviour were taken into account in the microscopic models. The first assumption for capacity evaluation by a microscopic traffic model is a calibration process which is based on traffic surveys results. Thus created models allow several capacity analyses during the peak traffic loading. Then, the results of micro-simulation can be compared with the capacity evaluation according to the technical regulations. The article deals with creation and calibration of microscopic traffic models and with the mentioned comparing of results.
Results of Automatic Identification of Transport Units in Postal Environment
Authors: Vaculík Juraj , Kolarovszki Peter , Tengler Jiří
Published: March 2012

Results of Automatic Identification of Transport Units in Postal Environment

This article primarily deals with identification of postal items and transport units in the logistic chain of postal operators. Nowadays, the identification is carried through barcodes and optical character recognition. In this article we would like to specify, how the transport units can be identified in the transmission process by RFID technology. In the carriage of postal items it is necessary to decide what type of transport is used for that purpose, what the flows of items are and what their intensity is. The RFID technology is complex, combining a number of different computing and communication technologies to achieve the desired objectives. Each object, which has to be identified, is stuck inside of a small object known as an RFID tag. RFID tag has a unique identifier, through which you can store additional information about the object. Equipments which are known under the name of RFID readers wirelessly, communicate with RFID tags with a view to identify RFID tags attached as well as the possibility to read and update information stored in the RFID label.

The article describes the scheme of the transport process, including planned technology and there is also simulated a real postal process in conditions close to operational.
An Itô Formula for an Accretive Operator
Authors: Léandre Rémi
Published: March 2012

We give an Itô formula associated to a non-linear semi-group associated to a m-accretive operator.
Theoretical and Experimental Study of LiBH4-LiCl Solid Solution
Authors: Zavorotynska Olena , Corno Marta , Pinatel Eugenio , Rude Line H. , Ugliengo Piero , Jensen Torben R. , Baricco Marcello
Published: March 2012

Anion substitution is at present one of the pathways to destabilize metal borohydrides for solid state hydrogen storage. In this work, a solid solution of LiBH4 and LiCl is studied by density functional theory (DFT) calculations, thermodynamic modeling, X-ray diffraction, and infrared spectroscopy. It is shown that Cl substitution has minor effects on thermodynamic stability of either the orthorhombic or the hexagonal phase of LiBH4. The transformation into the orthorhombic phase in LiBH4 shortly after annealing with LiCl is for the first time followed by infrared measurements. Our findings are in a good agreement with an experimental study of the LiBH4-LiCl solid solution structure and dynamics. This demonstrates the validity of the adopted combined theoretical (DFT calculations) and experimental (vibrational spectroscopy) approach, to investigate the solid solution formation of complex hydrides.
Photosensized Controlling Benzyl Methacrylate-Based Matrix Enhanced Eu3+ Narrow-Band Emission for Fluorescence Applications
Authors: Lee Jiann-Fong , Chen Hsuen-Li , Lee Geneh-Siang , Tseng Shao-Chin , Lin Mei-Hsiang , Liau Wen-Bin
Published: March 2012

This study synthesized a europium (Eu3+) complex Eu(DBM)3Cl-MIP (DBM = dibenzoyl methane; Cl-MIP = 2-(2-chlorophenyl)-1-methyl-1H-imidazo[4,5-f][1,10]phenanthroline) dispersed in a benzyl methacrylate (BMA) monomer and treated with ultraviolet (UV) light for polymerization. Spectral results showed that the europium complex containing an antenna, Cl-MIP, which had higher triplet energy into the Eu3+ energy level, was an energetically enhanced europium emission. Typical stacking behaviors of π–π interactions between the ligands and the Eu3+-ion were analyzed using single crystal X-ray diffraction. Regarding the luminescence performance of this europium composite, the ligand/defect emission was suppressed by dispersion in a poly-BMA (PBMA) matrix. The underlying mechanism of the effective enhancement of the pure Eu3+ emission was attributed to the combined effects of structural modifications, defect emissions, and carrier charge transfer. Fluorescence spectra were compared to the composite of optimized Eu3+ emission where they were subsequently chelated to four metal ions via carboxylate groups on the BMA unit. The optical enhanced europium composite clearly demonstrated highly efficient optical responses and is, therefore a promising application as an optical detection material.