bluuebunny/crossref_metadata_2025 huggingface dataset:
Trauma Deserts: Distance From a Trauma Center, Transport Times, and Mortality From Gunshot Wounds in Chicago
Authors: Crandall Marie , Sharp Douglas , Unger Erin , Straus David , Brasel Karen , Hsia Renee , Esposito Thomas
Published: April 2013

Objectives. We examined whether urban patients who suffered gunshot wounds (GSWs) farther from a trauma center would have longer transport times and higher mortality.

Methods. We used the Illinois State Trauma Registry (1999–2009). Scene address data for Chicago-area GSWs was geocoded to calculate distance to the nearest trauma center and compare prehospital transport times. We used multivariate regression to calculate the effect on mortality of being shot more than 5 miles from a trauma center.

Results. Of 11 744 GSW patients during the study period, 4782 were shot more than 5 miles from a trauma center. Mean transport time and unadjusted mortality were higher for these patients (P < .001 for both). In a multivariate model, suffering a GSW more than 5 miles from a trauma center was associated with an increased risk of death (odds ratio = 1.23; 95% confidence interval = 1.02, 1.47; P = .03).

Conclusions. Relative “trauma deserts” with decreased access to immediate care were found in certain areas of Chicago and adversely affected mortality from GSWs. These results may inform decisions about trauma systems planning and funding.
Estimation of Distribution Algorithms Applied to History Matching
Authors: Abdollahzadeh Asaad , Reynolds Alan , Christie Mike , Corne David , Williams Glyn , Davies Brian
Published: April 2013

The topic of automatically history-matched reservoir models has seen much research activity in recent years. History matching is an example of an inverse problem, and there is significant active research on inverse problems in many other scientific and engineering areas. While many techniques from other fields, such as genetic algorithms, evolutionary strategies, differential evolution, particle swarm optimization, and the ensemble Kalman filter have been tried in the oil industry, more recent and effective ideas have yet to be tested. One of these relatively untested ideas is a class of algorithms known as estimation of distribution algorithms (EDAs). EDAs are population-based algorithms that use probability models to estimate the probability distribution of promising solutions, and then to generate new candidate solutions. EDAs have been shown to be very efficient in very complex high-dimensional problems.

An example of a state-of-the-art EDA is the Bayesian optimization algorithm (BOA), which is a multivariate EDA employing Bayesian networks for modeling the relationships between good solutions. The use of a Bayesian network leads to relatively fast convergence as well as high diversity in the matched models. Given the relatively limited number of reservoir simulations used in history matching, EDA-BOA offers the promise of high-quality history matches with a fast convergence rate.

In this paper, we introduce EDAs and describe BOA in detail. We show results of the EDA-BOA algorithm on two history-matching problems. First, we tune the algorithm, demonstrate convergence speed, and search diversity on the PUNQ-S3 synthetic case. Second, we apply the algorithm to a real North Sea turbidite field with multiple wells. In both examples, we show improvements in performance over traditional population-based algorithms.
Impact of Reservoir Permeability on Flowing Sandface Temperatures: Dimensionless Analysis
Authors: App J.F.. F. , Yoshioka K..
Published: April 2013

Layer flow contributions are increasingly being quantified through the analysis of measured sandface flowing temperatures. It is commonly known that the maximum temperature change is affected by the magnitude of the drawdown and the Joule-Thomson expansion coefficient of the fluid. Another parameter that strongly impacts layer sandface flowing temperatures is the layer permeability. Aside from determining the drawdown, the layer permeability also affects the ratio of heat transfer by convection to conduction within a reservoir. The impact of permeability can be represented by the Péclet number, which is a dimensionless quantity representing the ratio of heat transfer by convection to conduction. The Péclet number is directly proportional to reservoir permeability. Through dimensionless analysis, it will be shown that for a given drawdown (based on a dimensionless Joule-Thomson expansion coefficient JTD) the temperature change diminishes at low Péclet numbers and increases at high Péclet numbers. This implies that for low-permeability reservoirs such as shale gas or tight oil, the temperature changes will be minimal (less than 0.1ºF) despite the large drawdowns in many instances. Dimensionless analysis is performed for both steady-state and transient thermal models. Results from multilayer transient simulations illustrate the ability to identify contrasting permeability layers on the basis of the Péclet number effect.
Estimation of the Formation Rate Constant of Methane Hydrate in Porous Media
Authors: Fukumoto Ayako , Sato Toru , Kiyono Fumio , Hirabayashi Shinichiro
Published: April 2013

Hydrate formation and the relevant mass and heat transfers were numerically analyzed in a microscopic computational domain in which spherical glass beads, water, and methane gas were distributed separately. A hydrate-formation experiment was also carried out by use of a cylindrical pressure cell. The temperature in the cell was controlled by Peltier devices, which were attached to the outer walls of the cell to imitate the adiabatic boundary condition present in the numerical simulation. By history matching between the experiment and calculation, we first obtained a hydrate-formation rate constant per unit volume of water, assuming homogeneous nucleation. Then, after converting the rate by use of a surface-area model of water in porous media, we noted that the area-based rate constant and activation energy of the hydrate formation were estimated to be 6.33 × 1034 mol·m–2 Pa–1 s–1 and 238 × 103 J/mol, respectively, for temperatures of 1.5 to 3.4°C.
Acid Stimulation Learnings from an Unconventional Reservoir
Authors: Popa Andrei , Sivakumar Kailash , Hao Minshen , Cassidy Steve
Published: April 2013

The California's Monterey formation is thought to hold significant hydrocarbon potential and is looked upon as a long term opportunity for development. Given its unique depositional environment, digenesis and very low permeability the hydrocarbon bearing formations have been referred as unconventional reservoirs. Since early 1900's the San Joaquin Valley's Monterey formation has been targeted and produced by several determined and ambitious operators. Still today, these operating companies are trying to develop an understanding of how to best develop and economically unlock this potential to further exploit the resource.

Different stimulation techniques, such as hydraulic fracturing and acid treatments, have been used in an attempt to unlock the resource. It was observed that, while hydraulic fracturing was to some extent effective in several fields, other reservoirs have been found to respond very well to acidizing treatments. The wealth of acid treatment data and corresponding production response from the Monterey formations present a great analysis opportunity to identify best practices and optimize well completions to maximize production.

This paper presents a study undertaken to analyze the acid stimulation treatments in one of the structures of the Monterey formation and consists of two parts. The first part covers the descriptive analysis and involves the use of supervised and unsupervised clustering techniques to evaluate the relationship between acid treatments and production data. Its objective is to understand the success of the treatments and to identify acid job best practices. In the second part, using only the available information and cluster knowledge extracted, an attempt was made to develop a predictive tool to forecast the performance of new/infill wells and re-stimulation treatments.

The study revealed a relatively good understanding of the factors affecting the production response of individual wells and also the variations observed in the different parts of the field. Shortly after the completion of the study, the operating company executed similar activities to what the study found, unbeknownst to the authors. The positive results achieved were not only a validation of the recommendations but also demonstrated the business value created by such analyses.
Environmentally Acceptable Corrosion Inhibitor for Filter-Cake Removal System
Authors: Misra Garima , Kumar Arunesh
Published: April 2013

The production of hydrocarbons with minimum drawdown pressure requires removal of the filter cake formed during overbalanced drilling. In such an operation, the delayed-breaker system used consists of an acid precursor that reacts slowly with water in the carrier brine and releases a strong organic acid, which dissolves the soluble part of the filter cake. However, exposure of downhole tools to acid at elevated temperature and pressure conditions can exacerbate the corrosion potential. Tool corrosion can lead to costly delays related to mechanical failure and workover operations.

Corrosion inhibitors are used to help minimize the impact of acids on metals. Stringent environmental regulations have increased industry emphasis on environmentally acceptable corrosion inhibitors, which not only provide good corrosion protection, but can be disposed of easily with minimal impact on the environment. As an example, North Sea environmental regulations are considered the benchmark for ecotoxicity and biodegradability parameters.

This study describes the corrosion protection potential of different food grade products. Experiments were conducted at 150 and 200°F using steel coupons and varying exposure times. Corrosion loss for different food grade products was less than 0.05 lbm/ft2 after 24 hr. No signs of pitting or crevice formation were observed on the metal coupons. After initial testing, products were screened for further investigation. Corrosion experiments conducted on steel grade metal with a food grade product from the legume family at 150°F resulted in a corrosion loss of 0.02 lbm/ft2 after seven days. Addition of corrosion inhibitor intensifier (CII), even at lower concentrations, enhanced the performance of inhibitors and made them suitable for higher-temperature applications. Corrosion experiments were also performed in the presence of calcium carbonate particles to simulate filter cake. Good inhibition was observed. A comparison of different food grade products applied as corrosion inhibitors and the practical limitations of these products is presented in this paper.
Effects of Wetting Behaviour on Residual Trapping in CO2-Brine Systems
Authors: Soroush Mansour , Wessel-Berg Dag , Kleppe Jon
Published: April 2013

After injecting CO2 into the formations containing brine, it starts to penetrate to upper sections and will be trapped under a geological barrier, during this period the formation brine will imbibe the CO2 and some portion of it will be trapped in the pore spaces. Capillary forces prevent complete drainage of CO2 and residual saturation remains trapped in the pores. Wetting behaviour of the CO2-brine system and relative permeability to each of the phases are important modeling parameters in this phenomenon. In such a system with cycling behaviour, hysteresis in relative permeability has strong effect on trapping. There are debates on wetting behaviour of candidate formations for CO2 storage. Different wettability conditions of the formations, affect the residual trapping mechanism. In this study, theoretical concept of residual trapping is defined through flow equations, and the effect of wettability is discussed by conceptual models. To verify the theoretical concept, different wettability conditions are modeled based on the Utsira formation of Sleipner reservoir and also the Viking formation (Canadian brine formation). Hysteresis in relative permeability and capillary pressure is considered in the modeling of both cases.

Results indicate that different wettability cases including strongly water wet to intermediate and slightly water wet condition, gives variation in the predicted trapped volume of CO2. This variation is from about 2 to 13% in different scenarios of this case study. Results of the simulations verify that wettability behaviour has both short and long term consequences in CO2 trapping. In low permeability simulation case, residual CO2 volume is more sensitive to the wettability condition. Results are dependent on the choice of hysteresis models but wetting behaviour of the system is the main subject that is targeted in this study.
A Novel Mud Formulation for Drilling Operations in the Permafrost
Authors: Kamel Ahmed H.
Published: April 2013

Umiat field is located in the North Slope, Alaska where most oil reserves are within the permafrost. The formation temperature is around 20°F and thus frozen filtrate is a crucial issue in formation damage. Frozen filtrate can form an impermeable barrier to oil flow and maximize formation damage in the permafrost. Its impact is even more pronounced in horizontal wells. In addition to formation damage concerns, low formation pressure, sensitive arctic environment and ice disintegration when exposed to certain fluids are key factors to be considered when selecting the suitable drilling fluid. This paper is a comprehensive experimental investigation of various drilling fluids to eventually propose a non-damaging fluid system that is suitable for permafrost drilling operations. Specially formulated, free-solid mud systems including WBM, brine mud, native crude OBM, synthetic oil mud, emulsion and foam are evaluated. The evaluation includes their rheological properties, filtration properties, clay swelling properties and potential freezing of fluid filtrate.

The results show that WBM drastically damage the formation. Yet, clay swelling is not a major issue. Freezing of water filtrate is the key damaging mechanism. In spite of its large filtrate volume, brine mud shows a moderate impact on formation damage. Its depressed freezing point makes it suitable for the drilling operations. However, it may not be preferable due to its ice disintegration effects. OBM and synthetic oil mud yield the minimal damage and show excellent rheological and filtration properties. Their depressed freezing point favors their use. Foams and emulsions exhibit numerous advantages. The analysis and evaluation of the different fluid systems is discussed in more details in the present paper. Finally, a specific formulation of drilling fluid is recommended to alleviate the formation damage and production impairment problems and to effectively reduce the well completion cost and eventually, to increase well productivity from such shallow frozen oil field.
Interpreting Pressure and Flow Rate Data from Permanent Downhole Gauges Using Convolution-Kernel-Based Data Mining Approaches
Authors: Liu Yang , Horne Roland N.
Published: April 2013

The convolution kernel was initially invented and applied in the domain of nature language machine learning. In the original linguistic study, the convolution kernel decomposed words into parts, and evaluated the parts using a simple kernel function. This inspired us to apply the convolution kernel method to data from permanent downhole gauges (PDG) by decomposing the pressure transient into a series of pressure responses to the previous flow rate change events.

In this study, the data mining process was conducted in two stages, namely learning and prediction processes. In the learning process, the PDG data were used to train the convolution-kernel-based data mining algorithm until the algorithm converged. After convergence, the reservoir model is obtained implicitly in the form of polynomials in the high-dimensional Hilbert space defined by the convolution kernel function. In the prediction process, a pressure prediction was made by the data mining algorithm according to an arbitrary given flow rate history (usually a constant flow rate history for simplicity). This flow rate history and the corresponding pressure prediction revealed the reservoir model underlying the variable PDG data.

13 synthetic cases representing different well/reservoir models and three real field cases were used to test this approach. The method recovered the reservoir model successfully in all cases.
Optimal Voidage Replacement Ratio for Viscous and Heavy Oil Reservoirs
Authors: Delgado D. E. , Vittoratos E. , Kovscek A. R.
Published: April 2013

Historically a voidage replacement ratio (VRR) of 1 is assumed to be optimal for oil recovery regardless of whether recovery occurs from an unconventional heavy oil reservoir or a conventional oil reservoir. That is, it is assumed that of all scenarios, the most oil recovery occurs when the amount of fluids injected into the subsurface equals the amount produced. Recent work publications have analyzed both field and core-scale data to conclude that a VRR of 1 is suboptimal for certain viscous and heavy-oil reservoirs. In this work, we use numerical simulation to seek an understanding of the conditions under which a VRR of 1 is suboptimal. Models are core-size to enable better interpretation of mechanisms. We tested the sensitivity of the optimal VRR to the curvature of our relative permeability relationships (i.e., Corey exponent), the critical gas saturation, the three-phase flow model, potential chemistry of the oil, the statistics of permeability values, the connectivity of low and high permeability regions, and the reference scale at which results are compared. Realistic relative permeability curves based off rock and fluid interactions observed in the literature were developed and used in the majority of our simulations. We find that gas mobility is an influential parameter in determining the optimal VRR at core scale. As the gas mobility decreases relative to oil and water and/or the reservoir heterogeneity increases, a VRR below 1 becomes more favorable. The heterogeneity and its connectivity also influenced the optimal VRR to a lesser extent.
Potential for Non-thermal Chemical Augmented Waterflood for Producing Viscous Oils
Authors: Xu Haomin , Kim Do Hoon , Delshad Mojdeh
Published: April 2013

Chemical Enhanced Oil Recovery (EOR) has regained its attention because of high oil price and the depletion of conventional oil reservoirs. This process is more complex than the primary and secondary recovery and requires detailed engineering design for a successful field-scale application.

An alkaline/co-solvent/polymer (ACP) formulation was developed and corefloods were performed for a cost efficient alternative to alkaline/surfactant/polymer floods. Alkali reacts with acidic components of heavy oil (i.e. 170 cp in-situ viscosities) to form natural soap and significantly reduce the interfacial tension, which allows producing residual oil not contacted by waterflood or polymer flood alone. Polymer provides mobility control to drive chemical slug and oil bank. Co-solvent helps to improve the compatibility between in-situ soap and polymer and to reduce microemulsion viscosity. An impressive recovery of 70% of the waterflood residual oil saturation was achieved from an outcrop core where the remaining oil saturation after the ACP flood was reduced to only 13.5%. The results were promising with very low chemical utilization. UTCHEM reservoir simulator was used to model the coreflood experiment to obtain parameters for pilot scale simulations. Geological model was based on unconsolidated reservoir sand with multiple seven spot well patterns.

However, facility capacity and field logistics, reservoir heterogeneity as well as mixing and dispersion effects might prevent the design followed in coreflood to be directly scaled for field implementation. Field-scale sensitivity simulations were conducted to optimize the design. The influence of chemical mass, slug size, polymer pre-flush, and injection rates on ultimate oil recovery was investigated. This research emphasizes the importance of small well spacing and good mobility control on recovery efficiency. The in-situ soap generated from alkali-naphthenic acid reaction not only mobilizes residual oil to increase oil recovery, but also enhances water relative permeability to increase injectivity.

The paper discusses a cost effective chemical flooding design with an impressive oil recovery by adding relatively small solvent and polymer quantities to injected water. The potential for producing residual oil of the viscous oil is demonstrated in both the coreflood and pilot-scale simulations.
Improved Oil Reservoir Characterization: Offshore Malaysia Field
Authors: Hassan Rozlin , Malaysia Lundin , Haddad Sammy , Wa Wee Wei , Johan Zailily , Lim Lee Chin
Published: April 2013

The acquisition of high quality reservoir information in exploration campaigns is a continuous challenge in today's operations. The operational risks, time, cost, environmental concerns and reservoirs complexities are several important factors to be considered in reservoir characterization planning. Key reservoir information includes fluid types and composition, horizontal permeability, vertical permeability, damage skin, radius of investigation and reservoir pressure.

This work presents the reservoir evaluation done in the basement with the mobility range of 0.01 to 0.09 mD/cP in an offshore Malaysia oil field. An early and quick identification of hydrocarbon prospect was required for appraisal wells planning. The expected low mobility in basement complicates the exploration data acquisition. Conventional reservoir fluid characterization through bottom hole sampling and PVT lab analysis is proven to be ineffective due to the long waiting time before the results are available. Full scale DST on the other hands offers higher operational complexity and cost for reservoir parameters determination.

As an alternative, the wireline formation tester dual packer module was deployed to perform a DST like testing known as interval pressure transient test (IPTT). At the interval of interests with the presence of hydrocarbon, the dual packer module offers selectively straddling reservoir sections to provide the capability to conduct controlled local production and interference for reservoir parameters estimation through pressure transient analysis. Downhole fluid analysis was performed to provide the reservoir fluid properties input. By providing larger flow area also, dual packer module enables the reservoir characterization in the low mobility intervals through downhole fluid analysis and IPTT techniques. The examples of IPTT applications in oil reservoirs and the analysis methodology will be presented in this paper.
Effect of Bitumen Viscosity and Bitumen-Water Interfacial Tension on the Efficiency of Steam Assisted Bitumen Recovery Processes
Authors: Romaniuk N. , Little L. , Arguelles F. A. , Babadagli T. , Ozum B.
Published: April 2013

In Alberta, Canada bitumen is commercially produced by in-situ processes at about 830,000 bbl/d capacity, production capacity is projected to exceed 5,000,000 bbl/d in the next two decades. Steam assisted gravity drainage (SAGD) process is one of the in-situ bitumen recovery processes; the economics and efficiency of which would be improved by reducing the steam to bitumen ratio. For this purpose, the addition of light hydrocarbon solvents into steam as a solvent to reduce bitumen viscosity has been studied; however, several decades of research efforts has resulted in only limited commercial success. More recently, as an alternative to solvent addition, the use of biodiesel (fatty acid methyl esters) with steam as a surfactant additive reducing bitumen-water interfacial tension was proposed and studied experimentally (Babadagli et al, 2009; Babadagli and Ozum, 2010).

In the present study, experiments were performed at typical reservoir pressure conditions to evaluate the performance of solvent (pentane) addition with steam to reduce viscosity and biodiesel addition with steam to reduce bitumen-water interfacial tension to improve bitumen recovery efficiency. The results showed that bitumen recovery efficiency may decrease with the addition of hydrocarbon solvent if the solvent is added after a certain period of steam injection. Solvent addition to the steam was tested at 5% and 15% of bitumen mass dosages. Steam assisted bitumen recovery tests with biodiesel addition under 2-g/kg-bitumen dosage showed an increase in bitumen recovery efficiency. To further investigate the reasons behind the lowered recovery with solvent addition, an analytical model was developed to predict heat transfer and pressure fields in the reservoir causing Darcy flow, and therefore, bitumen mobility. The distribution of the aqueous and solvent phases injected in time and space considering the phase change (steam and solvent condensation) effect with respect to steam chamber were clarified for different injection conditions and scenarios.

The results and observation will be useful in defining the appropriate application conditions for both solvent as a viscosity reducer and biodiesel as an interfacial tension reducer additive in SAGD operations.
Clastic and Carbonate Formation Evaluation Case Study: East Asia
Authors: Bt Zulkipli Siti Najmi , Kyi Ko Ko , Haddad Sammy , Johan Zailily , Wa Wee Wei , Tan Willy , Sinnappu Suresh
Published: April 2013

Proving a hydrocarbon bearing zone has a significant impact on appraising a well. Pressure gradient and fluid sampling are typically used to identify fluid type in exploration phase. In addition, to confirm if the field is viable for oil & gas production, there is a need to ascertain volume of hydrocarbon from petrophysical evaluation. Aside from this evaluation, reference to adjacent development wells occasionally become common for the operator to aid in reservoir study and plan for development.

This work is based on a case study on a Sarawak Basin field, drilled with Water Base Mud, which has three reservoirs of interests stretching across Clastics and Central Luconia Carbonate on the bottom zone. The poor quality sand and tight upper zone are challenging for reservoir evaluation. This has called for the application of multi-frequency dielectric tool for fluid saturation and advanced downhole fluid analyzer to obtain PVT equivalent fluid analysis in real time.

With the dielectric tool showing the presence of hydrocarbon in both clastic and carbonate formations, downhole fluid analysis was planned to verify the mobile formation fluid and successfully guided the identification of oil and water in clastic formation and gas in the carbonate reservoir. The presence of water in clastic formation was not expected since the water producing interval is located at about 100 m down dip from a nearby development well that is producing gas. Dispute in results, in addition to tight nature of the reservoir has triggered the need for larger scale testing. A DST was initially planned by the operator after the well has been cased. With cost and time consideration, the decision was changed to run the formation tester dual packer module to perform interval pressure transient testing (IPTT). This paper will present the results of IPTT, fluid analysis and dielectric tool to demonstrate the methodology used in this case study field evaluation.
Liquid Lift Dual Gradient Drilling in Deep Water: Early Kick Detection and Control
Authors: Dhameliya J. D. , Jain S. , Gupta V.
Published: April 2013

As the demand for energy is increasing, the search for oil and gas extends into hostile and challenging environment. Among these problematical environments are the deepwater regions of the world. One of the many challenges faced when drilling deepwater offshore wells is the decreasing window between pore pressure and formation fracture pressure, which is one of the major reliability issues affecting the use of conventional drilling in deepwater. Also, for successful oil and gas exploration, increased accessibility to reserves, improved wellbore integrity, reduced overhead costs and most importantly, providing a safe working environment to take place in this area, new drilling methods must be developed to carry out drilling operations in deepwater.

Applying a dual gradient drilling (DGD) technology to offshore drilling isn't a new concept, but one that is being addressed with new fervor and can help meet all of these industry goals. DGD is a rapidly growing technology that has been used in deepwater for various applications nowadays such as, fewer required casing strings, larger production tubing, improved well control and reduction of lost-circulation setbacks etc.

In conventional drilling, after detecting a kick, the well is immediately shut in. But, in DGD due to the pressure imbalance the well cannot be shut-in until equilibrium is reached. Otherwise it may lead to formation fracture and lost circulation.

This paper focuses upon some of technology related to early kick detection in liquid lift DGD and once a kick is detected, how to stop the further influx and circulate the kick fluid out of the wellbore. To achieve this objective we have analyzed economic and institutional factor by the use of appropriate model predictive control variants. We have concluded our paper with some relevant recommendation on some operational and design strategies as well as future direction for integration of additional variable.
Coupling Programming of an Adaptive Genetic Algorithm with Reservoir Flow Simulation for Infill Oil Well Locations Optimization
Authors: Al-Mudhafer Wathiq J.
Published: April 2013

Planning of an optimal field development scenario in a mature oil field is a crucial decision since it requires an efficient design of integrated reservoir modeling. One of the most imperative field development scenario is determining the locations of infill wells. The reservoir under study is the main pay in the South Rumaila oil field. This is a mature oil field located in the South of Iraq with around 58 years of production. It has 40 producing wells and 20 injection wells. An efficient reservoir simulation model has been coupled in sequence with a stable and well-conditioned genetic algorithm to optimize the infill well locations. A Genetic Algorithm offers an efficient search method that can be used as a powerful optimization tool by randomly generating potential solutions in order to achieve increasingly better results by applying a set of operators: Selection, Crossover (Recombination), and Mutation.

In this study, a black oil reservoir model has been used to evaluate the reservoir and predict its future performance. After attaining a considerable history matching, the simulator has been coupled with an Adaptive Genetic Algorithm (AGA). This algorithm is coupled with the simulator in order to re-evaluate the optimized wells at each iteration. Net Present Value (NPV) has been adopted here as an objective function. The initial population consists of a random number of chromosomes that have eight genes that represent the number of possible new proposed wells that have the highest values of permeability and oil saturation at the last time step. The genetic algorithm takes two parents randomly from the population and produces two children (offspring) by applying the operators such as crossover, mutation, and replacement on the two parents. Subsequently, the program sorts the population' chromosomes from best to worst. The resulting chromosome represents the optimal wells at this iteration. Then the AGA program re-inputs the optimized wells in the input file of the simulator to repeat the processes for many iterations until the optimal solution with the highest NPV is obtained. The entire procedure has led to optimize three infill wells that have the highest NPV among the other solutions.
Bioenergy for Cattle and Cars: A Switchgrass Production System that Engages Cattle Producers
Authors: Mosali Jagadeesh , Biermacher Jon T. , Cook Billy , Blanton John
Published: April 2013

Switchgrass (Panicum virgatum L.) produced for bioenergy is expected to compete with land resources used for stocker cattle (Bos taurus) grazing in the southern Great Plains. The objective was to determine the effect of stocking rate on animal performance, biomass yield, and quality. Three stocking rates (light [2.5 steers ha–1], moderate [4.9 steers ha–1], and heavy [7.4 steers ha–1]) and an ungrazed control were randomly assigned to twelve 0.81‐ha paddocks in 2008, 2009, and 2010. Animal and biomass responses were analyzed using mixed ANOVA models. Average daily gain (P = 0.05) was 0.83, 1.04 and 1.05 kg head (hd)–1 for the light, moderate and heavy stocking rates, respectively. Grazing duration was affected (P < 0.001) by stocking rate treatment, realizing 81, 43, and 28 d of grazing, respectively. Steer grazing days were not different (P = 0.22) between stocking rates treatments, producing 81, 86, and 84 d ha–1, respectively. Total gain by treatment were 167, 215, and 199 kg ha–1, respectively, and were different (P = 0.04). The ungrazed control produced more (P < 0.001) harvested biomass at the end of the growing season (15.3 Mg ha–1) compared to the grazed treatments (10.6, 8.1, and 7.8 Mg ha–1, respectively). Forage quality decreased (P < 0.05) throughout the growing season for all treatments. Results indicate switchgrass has the potential to extend the cool‐season grazing season in the region while also allowing for the production of an annual supply of bioenergy feedstock for conversion into biofuel.
Yield Potential of Hulless Versus Hulled Full‐Sib Genotypes in Four Winter Barley Populations
Authors: Berger G. , Green A. , Brooks W. , Vaughn M. , Pitman R. , Thomason W. , Griffey C.
Published: April 2013

Determining what factors contribute to the yield difference that exists between hulled and hulless winter barley (Hordeum vulgare L.) is necessary for continued yield improvement in the hulless barley germplasm pool. This yield difference is a major factor limiting the acceptance and production of hulless barley as an alternative to traditional hulled barley. Experiments were conducted in Warsaw, VA, during 2010/2011 and 2011/2012 and in Blacksburg, VA, during 2011/2012. Seedling emergence, plants per square meter, normalized difference vegetative index, heading date, spikes per square meter, plant height, lodging, yield, grain volume weight, 1000 kernel weight, spikelets per spike, seeds per spike, seed weight per spike, ash, crude fiber, fat, protein, and starch were measured. Grain volume weight and protein concentration were significantly (p ≤ 0.05) higher for hulless genotypes while seedling emergence and grain ash concentration were significantly (p ≤ 0.05) higher for hulled genotypes. Other traits measured in the study varied by population and environment. On the basis of linear regression analysis, none of the traits explained yield variation in all populations and environments. Before adjustment for hull weight, hulless genotypes yielded significantly (p ≤ 0.05) less than hulled genotypes on average in all populations at Warsaw and for population 1 at Blacksburg during the 2011/2012 growing season. After adjustment for hull weight, yield potential of select hulless genotypes was statistically similar to that of hulled genotypes. Therefore, it is possible to identify hulless genotypes having yield potentials equal to those of their hulled sibs.
Effect of Gypsum Application on Mineral Composition in Peanut Pod Walls and Seeds
Authors: Pathak Bhuvan P. , Jain Mukesh , Tillman Barry L. , Grusak Michael A. , Gallo Maria
Published: April 2013

Alleviation of soil‐Ca deficiency through gypsum amendment increases the yield potential and ensures high seed quality in peanut (Arachis hypogaea L.). The effects of gypsum treatment, plant life cycle, and the fruit development stages on the accrual of several essential minerals (Ca, S, Mg, P, K, Cu, Ni, Mn, Zn, and Fe) and Na were studied in the pod walls and seeds of two runner cultivars, C‐99R and Georgia Green. Calcium concentration was nearly twofold higher in pod walls than in seeds, irrespective of gypsum treatment and cultivar differences. Significant increases in Ca and S, a decrease in P concentration in pod walls and seeds, and a marginal decline in seed‐Mg concentration were discernible following gypsum treatment. Sodium concentration decreased in the pod walls and Zn concentration increased in the seeds due to gypsum treatment. Progression in the plant life cycle stage was positively correlated with Ca accrual in both pod walls and seeds. The small‐seeded cultivar Georgia Green showed tissue‐specific increases in the acquisition of Ca, Mg, and Zn in pod walls and seeds, and a decrease in P concentration in the seeds compared with the large‐seeded cv. C‐99R. Compared with the respective seed maturation stages, the pod walls had lower S, Mg, P, K, and Zn, and higher Ca, Cu, Ni, Mn, Fe, and Na concentrations. While Ca, S, Mg, P, K, Zn, Fe, and Na concentrations declined, Mn concentration increased in both pod walls and seeds during fruit development.
Predicting Saturated Hydraulic Conductivity for Estimating Maximum Soil Infiltration Rates
Authors: Arrington Kathleen E. , Ventura Stephen J. , Norman John M.
Published: April 2013

Pedotransfer functions (PTFs) can be used to estimate saturated hydraulic conductivity (Ks) from soil properties such as texture and bulk density. We evaluated several published PTFs to determine which was the most reliable for predicting maximum soil infiltration rates for soils in Dane County, Wisconsin. The PTFs were evaluated with a local database of measured infiltration rates (using a 5000‐cm2 infiltrometer), land use, soil properties (texture, bulk density, and organic matter content), and topographic properties (elevation, slope, and aspect) at 42 locations. We used Bayesian updating to combine local and national data to develop Dane County Ks estimates for some soil textural classes, some of which were subdivided into two porosity classes. We developed a local PTF for predicting Ksand examined the potential for using nonsoil properties (land use and topography) as predictors of Ks. The local PTF used the mass fraction of sand and bulk density as predictors; adding nonsoil predictors did not improve its accuracy. Although the local PTF had a lower root mean squared error (RMSE) than the published PTFs, it should be evaluated with an independent dataset. Of the published PTFs evaluated, the most reliable Ks estimate compared to the local database was the one used for soils with strong structure in the precision agricultural‐landscape modeling system (PALMS), a fine‐scale landscape process model. The Ks estimates developed by Bayesian updating corresponded well with those used in PALMS for soils with strong structure.
Roadside Memorials in Northeastern Thailand
Authors: Cohen Erik
Published: April 2013

In Thailand spirit houses are often established at places of fatal accidents, but these are generally anonymous. Personalized roadside memorials for accident victims are rare. This article analyses three roadside memorials, located on main roads in northeastern Thailand, in a comparative framework. Like in the contemporary West, such memorials commemorate a suddenly and violently killed person, but manifest a dynamics very different from that of Western roadside memorials: rather than private and temporary, these are permanent shrines, in which the spirit of the deceased is worshipped and supplicated by members of the public. The spirits and their shrines tend to become incorporated into the popular Thai magico-religious complex. While the literature offers a binary distinction between formal public monuments and informal, private and temporary (roadside) memorials, it is suggested that the informal, but public and permanent memorial shrines in Thailand exemplify a third type of edifices to commemorate the deceased in road accidents.
Association of Urinary Laminin G-Like 3 and Free K Light Chains with Disease Activity and Histological Injury in IgA Nephropathy
Authors: Rocchetti Maria Teresa , Papale Massimo , d’Apollo Anna Maria , Suriano Ida Valentina , Di Palma Anna Maria , Vocino Grazia , Montemurno Eustacchio , Varraso Leonarda , Grandaliano Giuseppe , Di Paolo Salvatore , Gesualdo Loreto
Published: April 2013

Background and objectives

IgA nephropathy has variable clinical presentation and progression. Its definitive diagnosis and prognosis require renal biopsy. The identification of new biomarkers allowing noninvasive diagnosis and monitoring of disease activity would be advantageous. This study analyzed the urine proteome of IgA nephropathy patients at an early stage of disease.

Design, setting, participants, & measurements

Urine from 49 IgA nephropathy patients, 42 CKD patients, and 40 healthy individuals was analyzed by surface-enhanced laser desorption/ionization time of flight/mass spectrometry. Differentially excreted proteins were identified by matrix-enhanced laser desorption/ionization time of flight/mass spectrometry, confirmed by immunologic methods, and validated in an independent set of patients (14 IgA nephropathy and 24 CKD). All patients were recruited at the Division of Nephrology of the University of Foggia from January of 2005 to March of 2007.

Results

Two proteins, with 21,598 and 23,458 m/z, were significantly decreased in IgA nephropathy and identified as Perlecan laminin G-like 3 peptide and Ig κ light chains, respectively. Western blot analysis confirmed the lower urinary excretion of laminin G-like 3 in IgA nephropathy patients compared with CKD patients and healthy individuals. Immunonephelometry analysis confirmed the lower urinary excretion of free κ light chains in IgA nephropathy patients compared with CKD patients and healthy individuals. Immunohistochemistry analysis justified the urinary excretion profile of such proteins in IgA nephropathy. Finally, urinary free κ light chains and laminin G-like 3 concentration inversely correlated with severity of clinical and histologic features of our IgA nephropathy cohort.

Conclusions

Laminin G-like 3 and free κ light chains can contribute to the noninvasive assessment of IgA nephropathy disease activity.
Lipoprotein Kinetics in Male Hemodialysis Patients Treated with Atorvastatin
Authors: Schwaiger Johannes P. , Nakada Yoshinobu , Berberich Ramona , Ikewaki Katsunori , Dieplinger Benjamin , Zitt Emanuel , Neyer Ulrich , Salmhofer Hermann , Kronenberg Florian , Koenig Paul , Dieplinger Hans
Published: April 2013

Background and objectives

In vivo metabolism of atherogenic apolipoprotein B (apoB)–containing lipoproteins is severely impaired in patients undergoing hemodialysis (HD), resulting in markedly prolonged residence times of these particles. It is unclear whether treatment with statins improves LDL kinetics in HD patients as is known for the general population. Therefore, this kinetic study assessed apoB-containing lipoproteins in these patients.

Design, setting, participants, & measurements

Kinetic measures were analyzed with stable-isotope technology in six men undergoing HD before and after 3 months of daily administration of 10 mg of atorvastatin. Patients were 18–65 years of age, had LDL cholesterol levels between 90 and 200 mg/dl, and had been treated with HD for >6 months. They consumed a standardized isocaloric diet for 3 days before analysis. Fractional catabolic rates (FCRs) and production rates of very-low-density lipoprotein (VLDL)–apoB, intermediate-density lipoprotein–apoB, and LDL-apoB were determined using multicompartment modeling after plasma lipoprotein separation, precipitation of apoB, and determination of tracer-to-tracee ratios using mass spectrometry.

Results

Plasma concentrations of VLDL- and LDL-apoB were significantly lower (mean ± SD, 7.77±2.62 versus 11.27±6.15 mg/dl, P<0.05; 56.9±23.9 versus 84.0±21.1 mg/dl, P=0.03) and their FCRs were significantly higher (7.20±3.08 versus 5.20±2.98 days−1, P<0.05; 0.851±0.772 versus 0.446±0.232 days−1, P<0.05) after 3 months of atorvastatin treatment. Accordingly, the residence times in plasma of VLDL- and LDL-apoB were significantly lower after treatment (0.14 versus 0.19 day and 1.2 versus 2.2 days, respectively).

Conclusion

Lower plasma concentrations and improved kinetics of atherogenic lipoproteins were observed in HD patients after administration of low-dose atorvastatin.
The Influence of Personality Traits, Health Knowledge, and Product Attributes on Intent to Purchase Taiwan's Healthcare Tourism Products
Authors: Lee Yi-Chih
Published: April 2013

In recent years, Asian countries have become committed to the development of healthcare tourism. In this study I explored the influence of the level of consumers' health knowledge involvement and product attributes on their intent to purchase healthcare tourism products available in
Taiwan. The results showed that consumers' purchase intent varied according to their level of health knowledge involvement and also according to individual consumers' personality traits. The findings in this study offer references for the tourism, transportation, and medical services industries
to make best use of sightseeing resources and advanced medical technology while actively marketing more attractive leisure activities to boost the economy of Taiwan.
Leadership Styles of Entrepreneurial Women in Eastern China: Characteristics and Differences
Authors: Li Chengyan , Bao Lili , Jiang Qiang
Published: April 2013

A number of studies have recently been conducted on entrepreneurship of women. In one study the researchers found that gender had an impact on entrepreneurial activity (Mueller & Conway Dat-On, 2008) and the characteristics of entrepreneurial women per se became the focus of research.
In our empirical research we explored the characteristics of, and differences among, the leadership style of a sample of 225 entrepreneurial women from Zhejiang Province and Shanghai in eastern China. We found that the majority of these women adopted an achievement-oriented style of leadership,
that is, a style consisting of high initiating structure and high consideration. We found differences in the consideration leadership style of the women according to the type of enterprise in which they were working; in addition there were differences in both initiating structure and consideration
leadership styles of the women entrepreneurs according to the length of time that the enterprise in which the women were working had been established.
THE RELATIONSHIP BETWEEN PERSONALITY TRAITS AND SOCIAL MEDIA USE
Authors: Özgüven Nihan , Mucan Burcu
Published: April 2013

In this study, we investigated the relationship between social media and users' personality factors. We used a questionnaire comprising the five-factor model of personality (McCrae & Costa, 1987), a life satisfaction scale (Diener, Emmons, Larsen, & Griffin, 1985) and a social
media marketing activities scale (Kim & Ko, 2011) to collect data from 503 Faculty of Economics and Administrative Sciences students. The results show that 2 personality traits (namely, conscientiousness and openness to experience), 2 demographic attributes (namely, education and income
level) and life satisfaction are significant predictors of social media use. The relationships with the other factors explored were not significant.