bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Dynamic Surface Activity of Surfactant on Performance of Foam for Gas Well Deliquification
Authors: Yang Jiang , Wang Xiaoling , Lu Yongjun , Guan Baoshan , Yang Guanke
Published: April 2013

As gas well flow rate decreases, liquid loading occurs in the wellbore and reduces the gas productions. Among various artificial lift methods for liquid removal, foam is one of most economic and widely used method. Foam process in gas deliquification is different from foam applications in drilling fluid and fracturing fluid. The foam for gas well deliquification is generated by gas flow in the tubing. The liquid is accumulated in the thin film of foam and plateau border area, which reduces the overall density of the fluid and unload liquid at lower gas flow rate. In this foaming process, a dynamic diffusion of surfactant to the interface is involved. Dynamic surface and elastic properties of foam are very important parameter to success in foam deliquification. We hereby studied the dynamic surface properties of the foaming surfactant by maximum bubble pressure tensiometer at high flow rate/frequency. The different molecular structures of surfactants were studied and compared. The dynamic surface activity is correlated well to performance of liquid unloading with foam column test method, while equilibrium surface activity obtained by Wilhelmy plate tensiometer is not correlated. Surfactant concentration can be also optimized by evaluation of its dynamic surface activity. For the foam evaluation test method, blender test is also widely used to in the industry to evaluate foam in gas well deliquification. It was found that the two foam generation test methods gave different results when they were compared with the performance of different foamers. The blender foam test is more static, and is not simulated well to the real foam generating process in the gas well. Hence, dynamic surface activity of surfactant by maximum bubble pressure tensiometer gives a high throughput screening parameter to predict performance of different foamers for liquid deliquification.
Effect of Liquid Crystal on Gel Formation Rate of Viscoelastic Surfactant for Hydraulic Fracturing
Authors: Yang Jiang , Lu Yongjun , Guan Baoshan , Cui Weixiang , Qiu Xiaohui , Yang Zhen , Chen Junbin , Yang Guanke
Published: April 2013

The viscoelastic surfactant (VES) as low formation damage fluids can be used in hydraulic fracturing and acidizing of low permeability oil and gas reservoir. The physical association and entanglement of wormlike micelle in diluted range gives viscoelastic properties, which gives similar properties as polymer. Compared with traditional polymer fluids, VES fluids used few additives and were easy to prepare in the wellsite. However, some VES fluids could take a long time to dissolve and build up viscosity in the field operation when it is diluted from concentrate. Amphoteric VES is hereby studied to understand the cause of such problems. The phase behavior of the surfactant-solvent-water was investigated. It was found that a three phase range consisted of liquid crystal gel was passed during diluting process. It consisted of a hexagonal liquid crystal phase. Hexagonal liquid crystal is highly viscose rod-like aggregate, it took longer time, up to several hours, to dissolve to form VES in the lab and field test. A cosurfactant was added to concentrate to increase the dissolve rate. Transient hexagonal liquid crystal gel is transformed to lamellar liquid crystal gel upon addition of co-surfactant. The microstructure of liquid crystal is confirmed by cross-polarizer microscope and small angle X-ray diffraction. The lamellar liquid crystal with multi-layer structure has low viscosity. It forms VES and builds up in viscosity within 2 minutes in the lab tested, and can form VES on-the-fly in field blending. Addition of cosurfactant didn't change performance of the prepared fluid at high temperature. Hence, the liquid crystal phase structure is the critical factor for dissolving rate of VES concentrate in the field operation.
Energy Policy Analysis and Uncertainty
Authors: Blaskovich Frank
Published: April 2013

Developing energy policies that work well is a difficult task. Many factors can affect the results for all interested parties, including the government and energy producers. Good policies require an appreciation for the interactions among oilfield development and operations, costs and prices, government taxes and regulations, infrastructure failures, and many other factors. We built a system dynamics model of an oil province to explore how government tax policy might be impacted by uncertainties in field operations as well as parameters outside the normal purview of most model studies. We tried to identify those uncertain parameters that might have the largest impacts on energy policies for both the government and operators. The government and producer typically want the maximum possible profitability. However, the best solution (e.g., maximum net present value) is seldom, if ever, the same for everyone. We developed an approach using regret analysis to finding flexible and resilient tax policies, in spite of uncertainties, that would provide all parties with fair, profitable solutions – even though none might achieve their maximum goals.

Our model can quickly run thousands of scenarios and can also be used as a training simulator. This makes our approach very useful and flexible for government agencies, energy companies and both groups working together to find solutions that might otherwise not be explored.

We believe that significantly better policy solutions may be found using our approach than more traditional "linear" techniques in which simulation model results are subsequently used to perform economics analysis in a stepwise manner. Instead, we combine the important aspect of both plus other non-traditional factors to achieve solutions that depend on the interaction of the most important parameters.

We believe that this approach represents a useful new paradigm compared to techniques that focus on individual components and/or exclude non-traditional, but important factors. We emphasize the inter-relationships among those factors that greatly affect policies for the mutual benefit of all parties in ways that are unique compared to other approaches that have previously been reported in the petroleum literature.
Global Model for Failure Prediction for Rod Pump Artificial Lift Systems
Authors: Liu Yintao , Yao Ke-Thia , Raghavenda Cauligi S. , Wu Anqi , Guo Dong , Zheng Jingwen , Olabinjo Lanre , Balogun Oluwafemi , Ershaghi Iraj
Published: April 2013

This paper presents a new generalized global model approach for failure prediction for rod pumps. By embedding domain knowledge into an Expectation Maximization clustering algorithm, the proposed global model is able to statistically recognize pre-failure and failure patterns from normal patterns during the training stage. Compared with previous field-specific models, the enriched training set for the global model learns from much larger scale of normal and failure examples from all fields with which a generalized Support Vector Machine (SVM) is trained and is able to predict failures for all fields. The data set for this paper is taken from five real-world assets using rod pump artificial lift systems which contain nearly 2,000 rod pumps. The results show that the global model of failure prediction is capable of capturing future rod pump and tubing failures that produce acceptable precision and recall. The resulting global model is scalable and can be used for predicting failures for proactive maintenance to reduce lost oil production. Results from our case studies with multiple fields data show that precision and recall are better than 65% with this global model.

Our prior work [1] used machine learning techniques to generate high quality failure prediction models with good accuracy. However, these efforts suffer from two major drawbacks. First, this used machine learning techniques that require labeled datasets for training the model. Generating these labeled datasets is human-intensive and time-consuming. Second, this model is field-specific which is only applicable to the specific field from which the labeled dataset is derived. These field-specific models generally perform poorly on other fields because of the differences in the data characteristic caused by field geology, operational procedure, etc. Moreover, these models have to be maintained independently, which accordingly raises nontrivial maintenance costs.
Dynamic Soltion Approach to the Inclination and Amizuth of Bottom Rotating Drill String
Authors: Xue Qi-Long , Wang Rui-He , Huang Lei-Lei , Sun Feng
Published: April 2013

In the oil drilling process, measurement-while-drilling (MWD) system is usually used to provide real-time monitoring of the position and orientation of the bottom hole. Particularly, in rotary steerable drilling technology and application, how to accurately measure the spatial attitude (inclination, azimuth, tool face) of the bottom drilling tool in real time while the drill string rotating is a challenging problem. Current MWD surveying is performed along the well path at stationary survey stations, because of that the bottom drilling tool shows complex characteristics while rotating due to combined effect of their randomly nonlinear moving state, such as vertical vibration, horizontal vibration, and stick-slip. The effects of complex characteristics cause sensors to generate a great dynamic error which will accumulate gradually during attitude resolving, so ultimately measuring spatial attitude deviates seriously from the true value.

This is a huge challenge for signal processing. In this paper, a set of "strap-down" measurement system was developed, the triaxial accelerometer and triaxial fluxgate were installed near the bit, and real-time well deviation and azimuth can been measured even when the drill string was rotating. However, according to the drilling field tests, playback analysis on storage data of the underground measurement indicates that drill string vibration is the main reason for measurement errors.

So this paper proposed dynamic solution approach to the bottom of the rotating drill string attitude. By setting a time window, the real-time measurement of the accelerometer and the flux gate signal are processed and analyzed, the movement patterns of the rotary drilling tool at the bottom were judged within the time window.utilizing stick-slip vibration to improve measurement accuracy, reducing the impact of vibration on the measurement results at the same time. Although the stick-slip vibration should be avoided point of view the life of the drill string, we can still take advantage of it because of it cannot be avoided entirely.

A continuous measurement while drilling system was developed and a large number of field test data were also analyzed. Simulation results in Matlab showed that recommended dynamic survey approach could effectively enhance measurement precision, and deduce effect of vibration on resolve results.
SDPF: A Framework for Online, Real-time Cleansing of Upstream Operating Data
Authors: Banaei-Kashani Farnoush , Asghari Mohammad , Mofrad Mahdi Rahmani , Shahabi Cyrus , Brenskelle Lisa
Published: April 2013

Since the quality of the raw upstream operating data can be poor in many instances (due to errors, incompleteness, and inconsistency), there is often an urgent need to cleanse the data in real time before using the data for process and business decision-making. In this paper, we present the design and development of an integrated data cleansing framework that can address a variety of upstream operating data quality issues systematically. Our proposed framework, dubbed SDPF (short for Scalable Data Processing Framework), benefits from the following features: Online/Real-time Data Cleansing, Scalability, Configurability, Reusability, and Comprehensiveness. We have tested and verified the performance of our data cleansing system with both real upstream operating data collected and synthetic data.
Characterization and Analysis on Petrophysical Parameters of a Marine Shale Gas Reservoir
Authors: Wei Chenji , Qin Guan , Guo Wei , Yan Bicheng , Killough John E. , Wang Hongyan , Liu Honglin
Published: April 2013

Shale gas remains one of the hottest topics in the petroleum industry. Petrophysical characterization is an important step for a new shale gas play to better understand the geology of the formation, and it provides vital data to optimize production plan and stimulation design. However, there is little research on correlations between petrophysical parameters for shale gas reservoirs.

The methodologies involved in this study include experimental study, outcrop observation, statistical analysis, and numerical modeling. The Longmaxi shale formation, which is an emerging Lower Silurian marine shale play in China with huge potential according to preliminary explorations, was characterized petrophysically in detail, and research on correlations between different petrophysical parameters was conducted. More than 100 ft core samples were collected from target layers for experiments. Also, the reservoir properties of the Longmaxi shale were compared with those of shale gas plays in the United States, such as the Barnett and Marcellus. Furthermore, based on a robust in-house simulator exclusively for shale gas, a reservoir model was developed by integration of those available petrophysical data to evaluate the key production drivers for typical shale gas reservoirs.

After integrating results from all these methodologies and technologies, total organic content (TOC), vitrinite reflectance (Ro), porosity, permeability, mineralogy, and gas content were obtained. Then, analysis was carefully conducted, and some interesting observations were found, such as an intimate correlation between the clay content and desorbed gas content. Additionally, both similarities and differences between petrophysical properties were concluded from comparison between the Longmaxi Shale and shale gas plays in the US. Moreover, Simulation results quantified the effects of natural fractures and desorption for the production performance.

This study provides a methodology for understanding and characterizing other shale plays. In addition, it offers detailed evidence to support engineers and geologists for understanding the geology and optimizing production plan on the marine shale.
Development and Application of Near-Well Multiphase Flow Upscaling for Forecasting of Heavy Oil Primary Production
Authors: Li Hangyu , Chen Yuguang , Rojas Danny , Kumar Mridul
Published: April 2013

Near-well effects can have a strong impact on reservoir flow. Current reservoir modeling practice often uses coarse-scale flow simulation models, which may lead to biased results, compared with fine-scale models. In this work, we extend and apply a recently developed near-well multiphase flow upscaling technique to the coarse-scale simulation of heavy-oil primary production. For heavy oils, oil viscosity is a strong function of pressure when the pressure is below the bubble point. Therefore, the upscaled mobility functions (from near-well multiphase upscaling) depend on both pressure and saturation, which cannot be directly input to general purpose reservoir simulators. This is very different than the upscaled mobility functions for typical black-oil fluids, in which oil viscosity does not vary significantly with pressure. Accordingly, the upscaled mobility functions are often equivalent to upscaled relative permeabilities (as functions of saturation only). In this work, we develop two procedures to derive either the upscaled relative permeability or viscosity functions from the phase mobility functions, thus decoupling the dependency on pressure and saturation. It is found that the upscaled oil viscosity provides more accurate predictions than the upscaled relative permeabilities, especially at early time. This is because that the rapid change of pressure at early stage is captured sufficiently in the upscaled oil viscosity (as a function of pressure). The use of upscaled viscosity function in multiphase upscaling is new, and has not been presented in previous studies. We also introduce a grouping technique to reduce the number of upscaled flow functions in coarse-scale models. This is based on an observation that there is a strong correlation between the upscaled flow functions and the coarse-scale well-block permeabilities. The proposed methods are applied to realistic models from heavy-oil fields. For cases considered, the near-well multiphase flow upscaling considerably improves upon the standard coarse models. The use of upscaled relative permeability and viscosity functions, as well as the grouping of upscaled flow functions, provides practical applicability for fast and accurate forecast using coarse-scale models.
Relationship of Corn Yield, Biomass, and Leaf Nitrogen with Normalized Difference Vegetation Index and Plant Height
Authors: Yin Xinhua , McClure M. Angela
Published: April 2013

The strength of the relationships of corn (Zea mays L.) yield, plant biomass, and leaf N concentration with early‐ to mid‐growing season combined normalized difference vegetation index (NDVI) and plant height measurements has not been adequately documented. The objective of this study was to compare the strength among the relationships of corn yield, plant biomass, and leaf N with combined and respective NDVI and plant height measurements taken during the early to mid‐season under major cropping systems. Two field N rate response studies in non‐irrigated corn after soybean [Glycine max (L.) Merr.] (CS), non‐irrigated corn after cotton [Gossypium hirsutum (L.)] (CCT), non‐irrigated corn after corn (CC), and irrigated corn after soybean (ICS) were conducted at Jackson and Milan, TN, from 2008 through 2010. Regressions of corn yield, plant biomass, and leaf N concentration with NDVI × plant height and NDVI + plant height were slightly to markedly stronger in terms of R2 values than those of corn yield, plant biomass, and leaf N with NDVI alone during 6‐leaf growth stage (V6) to 12‐leaf growth stage (V12) regardless of cropping system. No strength difference was observed between the regressions of corn yield, plant biomass, and leaf N with NDVI × plant height or NDVI + plant height and with plant height alone. Our results suggest that the benefits are variable in using combined NDVI and plant height measurements to assess corn growth and N nutrition and/or predict corn yield relative to the utilization of NDVI measurements alone during the early‐ to mid‐season.
Phosphorus Uptake by Potato from Biochar Amended with Anaerobic Digested Dairy Manure Effluent
Authors: Collins Harold P , Streubel Jason , Alva Ashok , Porter Lyndon , Chaves Bernardo
Published: April 2013

Sorption of plant nutrients from dairy storage lagoons by biochar and use as a supplemental fertilizer is a beneficial strategy to reduce nutrient contamination around dairies and supply nutrients to potato (Solanum tuberosumL.) and other crops. This research evaluated potato growth responses and P partitioning from several rates of P applied as either mono‐ammonium phosphate (MAP) or as P recovered from anaerobic digested dairy manure using biochar. Single‐stemmed plants of the potato cultivars Ranger Russet and Umatilla Russet were grown in 7‐L pots containing Quincy sand soil (mixed, mesic Xeric Torripsamment). Biochar amended with dairy effluent applied at 5.7 and 11.4 Mg ha–1with fertilizer application rates equivalent to 55 and 110 kg P ha–1maintained adequate P levels in potato petioles of both cultivars through 85 d after planting. Total plant P uptake was greater for treatments receiving MAP. Total potato biomass and tuber yields of Umatilla Russet were 30 and 27% lower when amended with basic or enriched biochar compared to MAP treatments, respectively. Tuber biomass declined 10 and 20% for Ranger Russet and Umatilla Russet for the 11.4 Mg ha–1amended biochar, respectively compared to MAP fertilized treatments. Similar declines were found for the aboveground biomass and roots. The 5.7 Mg ha–1of enriched biochar supplied 70 to 80% of the P requirement for potato growth. These findings are an important step in providing evidence of the benefits of using recovered P as a fertilizer supplement to reduce the reliance on rock phosphates.
Diversity in Diploid, Tetraploid, and Mixed Diploid–Tetraploid Populations of Paspalum simplex
Authors: Brugnoli E. A. , Urbani M. H. , Quarin C. L. , Martínez E. J. , Acuña C. A.
Published: April 2013

The tetraploid cytotype of Paspalum simplex Morong has a wide geographical distribution and reproduces by apomixis while the diploid grows in a restricted area in northern Argentina and behaves as cross‐pollinated. The objective was to evaluate the genetic diversity among and within natural diploid and tetraploid populations of P. simplex growing in sympatry and allopatry by studying the phenotypic variability and DNA polymorphisms. Twenty‐three phenotypic traits and 10 inter‐simple sequence repeat (ISSR) molecular markers were used for evaluating the variability present in six populations of P. simplex. Two populations were diploid and four were tetraploid. One of the tetraploid populations was sympatric to a diploid population while the rest of the populations were allopatric. A rich diversity was observed for specific traits, especially for seasonal biomass yield, presence of a terminal raceme in the inflorescence, and leaf pubescence. The 2x and 4x populations growing in proximity were closely related. Diversity was higher within diploid populations when compared with the evaluated tetraploid populations. Among the tetraploid populations, the one sympatric with a diploid population exhibited the greatest diversity. Gene flow occurs between 2x sexual and 4x apomictic populations of P. simplex. Diploid populations seem to be the main source of the diversity observed among tetraploid populations.
Molecular Markers for Leaf Rust Resistance Gene Lr42 in Wheat
Authors: Liu Zhengli , Bowden Robert L. , Bai Guihua
Published: April 2013

Wheat leaf rust, caused by Puccinia triticina Eriks., is an important wheat (Triticum aestivum L.) foliar disease worldwide. Growing cultivars incorporating genetic resistance is one of the most effective approaches for disease control. Leaf rust resistance gene Lr42 was identified from a wheat relative, Aegilops tauschii Coss. (goatgrass), and has been transferred into hard winter wheat. A previous study identified two markers closely linked to the gene on the short arm of chromosome 1D (1DS) using a near‐isogenic population, but flanking markers for Lr42 were not found. In this study, a new mapping population was developed from a cross between ‘KS93U50’ (a Lr42 carrier) and a susceptible parent, ‘Morocco’. An F2 population was analyzed with all simple sequence repeat (SSR) markers available from chromosome 1D and F2 plants and F3 families were evaluated for seedling resistance to isolate PNMRJ, a rust isolate avirulent to Lr42. The F2 and F3 rust data showed that Lr42 was recessive. Seven markers formed the linkage group on chromosome 1DS. The Lr42 region was flanked by two SSR markers, Xwmc432 and Xgdm33, at 18 cM apart. The results confirmed that Lr42 is positioned on the distal end of chromosome 1DS. The flanking markers for Lr42 should be useful for map‐based cloning and marker‐assisted pyramiding of Lr42 with other leaf rust resistance genes.
Comparative Performance of Early‐maturing Maize Cultivars Developed in Three Eras under Drought Stress and Well‐watered Environments in West Africa
Authors: Badu‐Apraku B. , Oyekunle M. , Menkir A. , Obeng‐Antwi K. , Yallou C. G. , Usman I. S. , Alidu H.
Published: April 2013

Maize (Zea mays L.) is a major staple crop in West Africa and has the potential to mitigate the food insecurity in the subregion. However, maize grain yield is severely constrained by drought. A study was conducted at 13 locations in West Africa for 2 yr to determine genetic gains in yield of cultivars developed during three eras, 1988 to 2000 (first‐generation cultivars), 2001 to 2006 (second‐generation cultivars), and 2007 to 2010 (third‐generation cultivars) under drought and optimal conditions. Under drought, yield ranged from 1346 kg ha⁻1 for first‐generation cultivars to 1613 kg ha⁻1 for third‐generation cultivars with a genetic gain of 1.1% yr−1. Under optimal conditions, yield gain ranged from 3363 kg ha⁻1 for first‐generation cultivars to 3956 kg ha⁻1 for third‐generation cultivars with genetic gain of 1.3%. The average rate of increase in yield was 14 and 40 kg ha⁻1 yr⁻1 under drought and optimum conditions. Genetic gains in yield from first‐ to third‐generation cultivars under drought was associated with improved plant aspect and husk cover, whereas under optimum conditions it was associated with plant and ear aspects, increased ears per plant, plant and ear heights, and improved husk cover. Cultivars TZE‐W DT C2 STR, DTE‐W STR Syn C1, DT‐W STR Synthetic, 2009 DTE‐W STR Syn, and EV DT‐W 2008 STR were high yielding and stable across drought environments. Substantial progress has been made in breeding for drought tolerance during the last three decades.
Drought Tolerance in Maize: Indirect Selection through Secondary Traits versus Genomewide Selection
Authors: Ziyomo Cathrine , Bernardo Rex
Published: April 2013

Phenotyping maize (Zea mays L.) for drought tolerance is costly and time consuming. Our objectives were to determine (i) the heritability, genetic variance, and genetic correlations for grain yield and secondary traits in maize under drought and (ii) the efficiency of indirect selection through secondary traits versus genomewide selection. Testcrosses of 238 recombinant inbreds from the intermated B73 × Mo17 population were evaluated in multilocation trials under managed drought and nondrought (control) conditions in Minnesota in 2009 and 2010. Mean grain yield under drought was 52% of the mean grain yield in the control experiments. Heritability for grain yield was 0.37 ± 0.08 under drought and 0.60 ± 0.04 in the control experiments. Indirect selection based on anthesis‐silking interval, leaf senescence, leaf chlorophyll content, or grain yield in control conditions was not predicted to be more efficient than direct selection for grain yield under drought. Genomewide selection (with 998 markers) for grain yield under drought had a predicted relative efficiency of 1.24. Genetic correlations estimated from genomewide marker effects agreed well with correlations estimated from genetic covariances. Given that multiple cycles of marker‐based selection can be done per year in maize and that genotyping is cheaper than phenotyping for drought tolerance, our results suggest that genomewide selection could increase genetic gains per unit time for grain yield under drought.
Does Organic Residue Quality Influence Carbon Retention in a Tropical Sandy Soil?
Authors: Puttaso Aunnop , Vityakon Patma , Rasche Frank , Saenjan Patcharee , Treloges Vidhaya , Cadisch Georg
Published: April 2013

The influence of residue quality on soil organic C (SOC) retention has been called into question. A field experiment in Northeast Thailand, in which contrasting quality organic residues were applied yearly for 13 yr, was used to determine quantities, locations, and stability of SOC in the soil matrix and identify residue quality parameters affecting SOC stabilization in a tropical sandy‐textured soil. Total organic C (TOC) content was highest in intermediate‐quality tamarind (Tamarindus indica L.) at 3.58 g kg−1 (intermediate N, lignin, and polyphenol contents), followed by groundnut (Arachis hypogaea L.) stover at 2.63 g kg−1 (high N), dipterocarp (Dipterocarpus tuberculatus Roxb.) at 2.63 g kg−1 (low N, high lignin and polyphenols), and rice (Oryza sativa L.) straw at 1.77 g kg−1 (high cellulose). Microaggregates (Mi) (0.053–0.25 mm) stored the highest C content (34–49% of TOC), with tamarind having the highest C content. Carbon in large macroaggregates (>2 mm), small macroaggregates (0.25–2 mm), and free organic matter (>0.053 mm) was significantly positively correlated with C, lignin, and polyphenols. Carbon in microaggregates and fine particles (<0.053 mm) was significantly negatively correlated with C/N ratio. Soil fraction C was negatively correlated with residue cellulose contents. Protected C lost through mineralization in Mi was lower in tamarind (7% Mi‐C) followed by groundnut (9.5%), dipterocarp (17.7%), and rice straw (18.6%). It was significantly positively correlated with cellulose and C/N ratios but negatively correlated with N contents. Possible mechanisms of aggregate formation are based on microbial synthesis of both persistent (humic substances) and transient (polysaccharides) binding agents as influenced by residue quality. The results showed clearly that residue quality plays an important role in SOC accumulation in tropical sandy soils.
Net Greenhouse Gas Emissions Affected by Sheep Grazing in Dryland Cropping Systems
Authors: Barsotti Joy L. , Sainju Upendra M. , Lenssen Andrew W. , Montagne Clifford , Hatfield Patrick G.
Published: April 2013

Sheep (Ovis aries L.) grazing is an inexpensive method of weed control in dryland cropping systems, but little is known about its effect on net greenhouse gas (GHG) emissions. We evaluated the effect of sheep grazing compared with herbicide application for weed control on GHG (CO2, N2O, and CH4) emissions from May to October 2010 and 2011, net global warming potential (GWP), and greenhouse gas intensity (GHGI) in a silt loam under dryland cropping systems in western Montana. Treatments were two fallow management practices (sheep grazing [GRAZ] and herbicide application [CHEM]) and three cropping sequences (continuous alfalfa [Medicago sativa L.] [CA], continuous spring wheat [Triticum aestivum L.] [CSW], and spring wheat–pea [Pisum sativum L.]/barley [Hordeum vulgaris L.] hay–fallow [W‐P/B‐F]). Gas fluxes were measured at 3‐ to 14‐d intervals with a vented, static chamber. Regardless of treatments, GHG fluxes peaked immediately following substantial precipitation (>12 mm) and N fertilization mostly from May to August. Total CO2 flux from May to October was greater under GRAZ with CA, but total N2O flux was greater under CHEM and GRAZ with CSW than other treatments. Total CH4 flux was greater with CA than W‐P/B‐F. Net GWP and GHGI were greater under GRAZ with W‐P/B‐F than most other treatments. Greater CH4 flux due to increased enteric fermentation as a result of longer duration of grazing during fallow, followed by reduced crop residue returned to the soil and/or C sequestration rate probably increased net GHG flux under GRAZ with W‐P/B‐F. Sheep grazing on a cropping sequence containing fallow may not reduce net GHG emissions compared with herbicide application for weed control on continuous crops.
Optimization by RSM of the degradation of three phenolic compounds – hydroquinone, resorcinol and catechol – on Fe-modified clays
Authors: Baizig Manel , Jamoussi Bassem , Batis Narjès
Published: April 2013

A Fenton-type wastewater treatment, using clay catalysts (montmorillonite and kaolinite), was prepared and used to degrade three phenolic compounds: hydroquinone, resorcinol and catechol. The operating conditions of the degradation of these compounds are optimized by the response surface methodology (RSM) which is an experimental design used in process optimization studies. The results obtained by the catalytic tests and analyses performed by different techniques (X-ray diffraction, volumetric adsorption, atomic absorption spectroscopy and high performance liquid chromatography (HPLC)) showed that the modified montmorillonites have very interesting catalytic, structural and textural properties; they are more effective for the catalytic phenolic compound degradation, they present the highest specific surface and they may support iron ions. We also determined the optimal degradation conditions by tracing the response surfaces of each compound; for example, for the catechol, the optimal conditions of degradation at pH 4 are obtained after 120 min at a concentration of H2O2 equal to 0.3 M. Of the three phenolic compounds, the kinetic degradation study revealed that the hydroquinone is the most degraded compound in the least amount of time. Finally, the rate of the catalyst iron ions release in the reaction is lower when the Fe-modified montmorillonites are used.
Adsorption of mercury from aqueous solution by nontronite, Aspergillus niger, and hybrid material
Authors: Guerra Denis L. , Silva Ricardo A. R. , Mello Ivani
Published: April 2013

A natural nontronite clay sample from the Amazon region (Tocantins State, Serra da Messa Group, Brazil) was utilized for synthesis of a new biomaterial produced by a hybridization process of inorganic and organic materials. The new biomaterial was composed of an Amazon nontronite and fungal mass obtained from the Aspergillus niger fungus. The natural clay, biomass, and biomaterial samples were used in batch studies for adsorption of Hg2+ ions from aqueous solution. The effects of stirring time, adsorbent dosage, and pH on the adsorption capacity demonstrated that 70 min is sufficient to reach equilibrium at room temperature and over a pH range of 6.0–8.0. The maximum number of moles adsorbed was 9.47, 17.8, and 18.7 mmol g–1 for natural clay, biomass, and biomaterial, respectively. From the cation/basic center interactions for each material at the solid–liquid interface, by using calorimetry, the equilibrium constant and exothermic thermal effects were calculated. By considering the net interactive number of moles for mercury ion and the equilibrium constant, the enthalpy and negative Gibbs free energy could be calculated: ΔintH = −6.8 ± 0.11 to −6.0 ± 0.22 kJ mol–1; ΔintG = −20.5 ± 0.25 to −23.2 ± 0.22 kJ mol–1. The thermodynamic values indicated the existence of favorable conditions for interactions at the solid–liquid interface.
Trace level determination of bisphenol-A in wastewater and sewage sludge by high-performance liquid chromatography and UV detection
Authors: Banihashemi Bahman , Droste Ronald L.
Published: April 2013

The purpose of this study was to develop and optimize a simple and economical method for the extraction and determination of bisphenol-A (BPA), using high-performance liquid chromatography (HPLC) coupled with ultraviolet (UV) detection at environmentally relevant concentrations in both dissolved and particulate phases. To clean-up and pre-concentrate liquid samples, solid-phase extraction (SPE) method was optimized with regard to pH, volume, washing and elution solvents for high recovery of BPA and good clean-up. For sludge samples, four extraction methods, microwave-assisted extraction (MAE), ultrasonication extraction (USE), accelerated solvent extraction (ASE) and high-pressure homogenizer (HPH), were compared for isolation of BPA from activated sludge samples. Analysis was performed by optimized procedures using HPLC–UV. Recoveries of BPA from liquid and solid phases were determined to be 90–105 and 60–90%, respectively. MAE had the highest recovery among examined extraction methods. The method detection limits were 100 ng/L and 100 ng/g dry weight. To validate the method, a mass balance study was conducted with 100 mL spiked mixed liquor volatile suspended solids (VSS) samples from three laboratory-scale porous pot reactors and concentrations of BPA in liquid and solid phases were determined using the optimized conditions. The results had an average 86% overall recovery for all samples.
Pharmaceutical removal by the activated carbon process
Authors: Piel S. , Blondeau S. , Pérot J. , Baurès E. , Thomas O.
Published: April 2013

The adsorption of some major pharmaceutical products (sulfamethoxazole, caffeine, iopromide and carbamazepine) in water was evaluated using four types of activated carbon, three powdered activated carbon (PAC) and one fluidized, coagulated and flocculated activated carbon (FAC) extracted from a Carboplus®P pilot. These substances were the most frequently quantified (in 50% of samples at least) in surface waters of the Vilaine's basin (Brittany, France) during three sampling campaigns. Jar test experiments were carried out in order to assess the removal efficiency of the four activated carbons. Carbamazepine and caffeine were well removed with PAC with a maximum removal rate of 80% whereas it was more difficult for sulfamethoxazole and iopromide with a maximum of 39%. For each molecule, removal rates are clearly dependent on PAC nature. The overall results with FAC are clearly distinguishable from PAC tests with gains of performance on all target molecules (from 80 to >95%).
Sciatic Nerve Block in the Popliteal Fossa Using Lateral Approach in an
Infant with Goldenhar Syndrome
Authors: Astuto Marinella , Privitera Concetta , Gurrieri Carmelina , Guzzetta Giuseppe , Murabito Paolo , Gullo Concetta , Puntillo Roberta , Gullo Antonino
Published: April 2013

Goldenhar syndrome is a rare disorder characterized by a wide range of congenital malformations that may
cause difficulty in tracheal intubation and mask ventilation. We describe a case of a male infant with Goldenhar syndrome
successfully treated with general anesthesia with laryngeal airway mask and peripheral nerve block for club foot disease
surgery.
Investigating the Effects of Veridicality on Age Differences in Verbal Working Memory
Authors: Shake Matthew C. , Perschke Meghan K.
Published: April 2013

In the typical loaded verbal working memory (WM) span task (e.g., Daneman & Carpenter, 1980), participants judge the veridicality of a series of sentences while simultaneously storing the sentence final word for later recall. Performance declines as the number of sentences is increased; aging exacerbates this decline. The present study examined whether veridicality (whether the sentence was true or false) moderated age differences on a verbal working memory task. Results suggested that veridicality interacted with age and span size such that older adults were more negatively affected by false sentences, particularly under the lowest WM demands. Findings are discussed in terms of the role that veridicality may play in age differences in verbal working memory.
Change in Perceived Age in Middle and Later Life
Authors: Ward Russell A.
Published: April 2013

Analyses examine change in the age people “feel” ( felt age) and “would like to be” ( ideal age) (relative to current age) in middle and later life. Data are from 1,815 respondents in two waves (1995–96, 2004–06) of the Midlife in the United States Survey (MIDUS) who were age 40+ at Wave 1. In aggregate, people feel about the same amount younger but become increasingly distant from preferred age. Favorable health trends between waves and better expected future health are related to younger felt age, cross-sectionally and longitudinally. Health is not related to ideal age, but education and (for respondents younger than 60) better financial expectations are associated with less youthful ideal age. Patterns for felt age appear to reflect images of later life as a time of physical decline, whereas ideal age appears to be shaped more by socioeconomic considerations.
The Development of an Imaginative Thinking Scale
Authors: Lin Hsiao-Hui , Tsau Saiau-Yue
Published: April 2013

This article develops and examines an Imaginative Thinking Scale (ITS), a unique measuring method designed to evaluate the development of imagination. According to the studies of the researchers, including Vygotsky, Hill, Coleridge, and others, on the one hand, we elaborately distinguish the cognitive difference between imagination versus fantasy and imagination versus creativity; on the other hand, we present a “gyroscope theory,” based on the concept of Vygotsky's laws of imagination, to illuminate the arousing mechanism of imagination and to establish 4 constructs or subscales, implicit in the ITS, which are initiation, fluency, flexibility, and originality. The ITS consists of 13 open-ended items under these 4 subscales. The participants are 847 first-year undergraduates. Item Analysis and Confirmatory Factor Analysis are used to determine the Cronbach's a test-retest reliability, individual item reliability, component reliability, composite reliability, and construct validity of the ITS. Following a second-order Confirmatory Factor Analysis, the data support the experimental model of the ITS, evolving from our “gyroscope theory,” and can account for .46, .96, .55, and .20 of the variance associated with these 4 subscales: initiation, fluency, flexibility, and originality.
Haptic Learning of Spatial Concepts: Can Training in Raised-Line Drawings Improve Blind People's Spatial Capacity?
Authors: Dulin David , Hatwell Yvette , Chokron Sylvie
Published: April 2013

The purpose of this research was to evaluate the impact of instruction in raised-line drawings on the spatial imagery capacity of congenitally and late blind people. The participants first performed preliminary tasks in order to evaluate their individual level of experience in the recognition and production of raised-line drawings. Then, all the participants (experienced congenitally and late blind groups, non-experienced congenitally and late blind groups, and blindfolded sighted participants) were presented with a mental rotation task, a mental spatial displacement task, and a direction judgment task. After this pre-test, half of the non-experienced participants (congenitally and late blind) were trained for 6 months in the recognition and production of raised-line drawings. Then, all the groups were presented again with the 3 spatial tasks (post-test). Results showed that the experienced participants performed better than the non-experienced ones in all the spatial imagery tasks of the pre-test. Contrary to the non-trained participants, the trained participants improved their skills as revealed during the post-test, and they performed as well as the non-trained experienced blind groups on all the spatial tasks of the post-test. These data indicate that a short yet intensive training of the blind people had a significant effect and that the benefits generalize to other spatial tasks (i.e., mental rotation, mental spatial displacement, and direction judgment tasks). In addition to a better understanding of blind people's cognitive functioning, these results may have important implications regarding the value of line drawing training in the education of visually impaired people.
The Psychological Experience of Hospice Workers during Encounters with Death
Authors: Dearmond Isabelle M.
Published: April 2013

While the nature of their experience is unknown, hospice workers may unconsciously strive for encounters with death as a way of healing themselves and preparing for death. The purpose of this case study was to explore the psychological experience of hospice workers, whose repeated encounters with death may affect their own psyche. The study integrated psycho-biographical and hermeneutic methods. Personal growth was conceptually defined as a process of turning inward and integration of personal experiences into a larger reality. The elements supporting personal growth were present in 53 to 88% of the 17 hospice workers of the sample. The emerging themes were interconnectedness, suffering and sacrifice, and birth and rebirth. Caring to the dying becomes practice for one's own death and a form of renewal in the life of the hospice workers.
Teachers Perceptions of Effects of a Student's Death: A Phenomenological Study
Authors: Hart Linda , Garza Yvonne
Published: April 2013

When a student dies in a school setting many school professionals step in and offer grief services to the students affected. In the classrooms, teachers are expected to step in and help the students grieve; however, equivalent support for teachers seems to be lacking. This study explored the lived experiences of teachers who experienced the unanticipated death of a student. From the analysis, the following themes emerged: (a) releasing feelings, (b) resources (c) lost academic time and redirection, and (d) honoring the memory. The results of this study reinforce the need for training for school teachers to help them better cope with the death of a student. Particularly, school professionals are called on to be proactive in creating a model to have in place to actively support teachers dealing with the grief and loss of a student.
The Preparation of Graduate Health Professionals for Working with Bereaved Clients: An Australian Perspective
Authors: Breen Lauren J. , Fernandez Maria , O'Connor Moira , Pember Amiee-Jade
Published: April 2013

Students enrolled in health profession courses require grief education so that, upon graduation, they are able to meet the needs of clients living with loss and grief. We investigated grief and loss education in six Australian university programs—medicine, nursing, counseling, psychology, social work, and occupational therapy—drawing from course documents and face-to-face interviews with key staff and final-year students. Only the counseling course included a dedicated grief and loss unit. The nursing, medicine, and occupational therapy courses emphasized end-of-life issues rather than a breadth of bereavement experiences. The social work course taught grief as a socially-constructed practice and the psychology course focused on grief and loss in addiction. Several factors influenced the delivery of grief education, including staffing, time, placement opportunities, student feedback, and needs of each profession. The study provides an indication as to how future health professionals are prepared for grief and loss issues in their practice.
The Euthanasia-Religion Nexus: Exploring Religious Orientation and Euthanasia Attitude Measures in a Muslim Context
Authors: Aghababaei Naser
Published: April 2013

Using religious orientation paradigm, this twofold study examined the relationship between euthanasia attitude and religiosity, and compared single-item and multi-item scales of euthanasia attitude. Three hundred students were asked whether they view euthanasia as moral. In addition, participants completed the Euthanasia Attitude Scale (EAS) and Religious Orientation Scale-Revised. Results indicated that intrinsic religiosity was the strongest correlate of negative attitudes toward euthanasia. This type of religiosity explained additional variance when added to the two types of extrinsic religiosity (social, personal), but the reverse was not the case. The fairly strong correlation of intrinsic religiosity with the EAS provides evidence of construct validity for the EAS and proved it to be a better measure for assessing euthanasia attitude, rather than the single-item scale.
The Continuing Bonds of Bereaved Parents: A Ten-Year Follow-up Study with the Two-Track Model of Bereavement
Authors: Rubin Simon Shimshon , Shechory-Stahl Mor
Published: April 2013

This article examines how varieties of the continuing relationship to the deceased child are associated with life functioning among bereaved parents. The research employed a longitudinal design utilizing both quantitative and qualitative research methodology. Six bereaved parents who lost sons in war and who had extensive interview material and research protocols spaced 10 years apart were selected for this study. Half had improved over time and half had not improved or deteriorated. Analyses of the ongoing relationship to the deceased focused upon: (a) perceptions of the deceased and (b) nature of the ongoing relationship to the deceased son. On perception, parents who improved tended to describe their sons in very favorable terms. The parents whose condition remained static or deteriorated tended to describe their sons less positively, and with superficial and shallow descriptions. Regarding the nature of the ongoing relationship, parents whose condition improved over the years describe a close and significant relationship with the son. We conclude that while the relationship to the son continues for all the bereaved parents, it is how the deceased is recollected that is associated with the direction of bereavement outcome.