bluuebunny/crossref_metadata_2025 huggingface dataset:
Laboratory Investigation of Low-Tension-Gas Flooding for Improved Oil Recovery in Tight Formations
Authors: Szlendak S.M.. M. , Nguyen N.. , Nguyen Q.P.. P.
Published: August 2013

This paper establishes low-tension gas (LTG) as a method for submiscible tertiary recovery in tight sandstone and carbonate reservoirs. The LTG process involves the use of surfactant and gas to mobilize and then displace residual crude after waterflood at a greatly reduced oil/water interfacial tension (IFT). This method allows extending surfactant enhanced oil recovery (EOR) in sub-20-md formations in which polymer is impractical because of plugging, shear, or the requirement to use a low-molecular-weight polymer.

The proposed strategy is tested through the coinjection of nitrogen and a slug/drive surfactant solution. Results indicate favorable mobilization and displacement of residual crude oil in both tight-carbonate and tight-sandstone reservoirs. Tertiary recovery of 75−90% of residual oil in place (ROIP) was achieved for cores with 2- to 15-md permeability. High LTG tertiary recovery is contrasted with results from reference surfactant (no gas) flooding (28% ROIP tertiary recovery) and immiscible gas coinjection (no surfactant) flooding (13% ROIP tertiary recovery). In addition, high initial oil saturation was tested to determine the process tolerance to oil and to evaluate the potential for application during secondary recovery. Under such conditions, this method achieved a recovery of 84% of oil originally in place (OOIP), suggesting the potential application of this process at secondary recovery.

To better understand the physical mechanisms that affect mobilization and displacement, the early production of an elongated oil bank at reduced fractional flow of oil was shown to be an attribute of high crude-oil relative mobility and low pore volume (PV) available to mobile oil. This should favorably affect economics during chemical flooding by accelerating the production of an oil bank. Next, by application of salinity as a conservative tracer and oil material balance, gas saturation during LTG floods was calculated to be 18 to 22%. By comparing effluent salinity profiles across floods, a qualitative understanding of in-situ fluid dispersion associated with macroscopic displacement stability is developed. The results indicate that in-situ foaming was present, which enabled mobility control, and that stable displacement of in-situ fluids was achieved during flooding.
Expandable Solid-Steel Liner Applications in the Marcellus
Authors: Cameron J. R. , Cooper B. S. , Gusevik R. T.
Published: August 2013

In the Marcellus Shale gas play in Pennsylvania and West Virginia, solid-steel expandable liners have been used over the last three years to restore casing damaged by over-pressuring during completion operations and to cover unwanted perforations to enable hydraulic fracturing. This paper describes the technology of expandable solid-steel liners and presents representative case histories in the Marcellus Shale.

Solid-steel expandable liners are expanded downhole using a pressure-driven cone that enlarges the diameter of the liner by permanently deforming it beyond its yield point but not to failure. While expanding the liner, elastomeric seals on the outside are compressed against the base casing to provide pressure integrity and anchoring.

In the Marcellus Shale, one well experienced a casing split in the lateral section during the primary cement job, and in a second well, a casing split occurred in the lateral section while pressuring open the toe fracturing sleeve. In a third well, three sets of squeeze perforations over a 1,300-ft interval had to be covered. In a fourth well, circulation for a cement job could not be established requiring the lateral liner to be perforated over its entire length in order to squeeze cement behind the casing. All of these wells required restorations of 5-1/2-in. 20 lb/ft casing to enable hydraulic fracturing.

In the first well, the casing split was repaired using a standard single-joint of expandable liner allowing the fracturing treatment to be performed using controlled screenouts (sand plugs) for fracturing-stage diversion below the expandable liner. In the second well, the casing split was repaired using two standard joints of expandable liner and the fracturing treatment was performed using drillable composite fracturing plugs (frac plugs) set below the installed liner for fracturing-stage diversion. In the third well, three separate high-performance single joints of expandable liner were used to cover the three sets of squeeze perforations over the 1,300-ft interval to enable fracturing using frac plugs set below the three single-joint expandable liners. In the fourth well, the entire lateral was relined with the solid-steel expandable liner, maintaining inside diameter (ID) sufficient for fracturing with frac plugs set inside the liner. In all these shale gas wells, solid-steel expandable liners provided reliable and robust solutions enabling fracturing to proceed as planned.
A Workflow to Evaluate Porosity, Mineralogy, and TOC in the Utica-Point Pleasant Shale Play
Authors: Murphy Eric , Warner Matthew , Sarmah Bhaskar
Published: August 2013

Porosity is a key reservoir property used in petrophysical evaluations. Obtaining realistic porosity estimates in unconventional reservoirs is challenging using only conventional logs. Conventional log porosity measurements are affected by the presence of kerogen in organic-rich reservoirs. Techniques such as ΔLogR can be used to predict total organic carbon (TOC) which can be converted to kerogen volume. The kerogen volume can then be used to apply corrections to conventional porosity measurements. However, these techniques require prior knowledge of thermal maturity or core measurements such as vitrinite reflectance (Ro).

The predicted TOC can also be used in conjunction with geochemical elemental measurements for a more accurate assessment of formation kerogen and mineralogy, as well as for hydrocarbon volumes. Nuclear magnetic resonance (NMR) logs measure only the fluids present and represent a total porosity unaffected by solid components such as kerogen and bitumen. Recent observations in numerous unconventional resource plays indicate that NMR log porosity provides the best match to core porosity and does not require corrections for kerogen. NMR log porosity is available in real time as an input to the petrophysical model long before core measurements can be completed. The complex refractive index method (CRIM) in conjunction with mineralogy log data can be used to compute accurate dielectric porosities, which exclude both kerogen and hydrocarbon. Integrating core TOC, predicted TOC, mineral analysis, NMR, and dielectric information, a final verification of the kerogen volume, porosity, hydrocarbon content, and mineral analysis can be assessed.

Based on previous work in the Eagle Ford Shale, a comprehensive workflow was developed for unconventional source rock reservoir interpretation. The workflow integrates conventional logs, a geochemical log, an NMR log, and a dielectric log to predict TOC, kerogen volume, mineralogy, total porosity, and hydrocarbon volume. This paper will show results from the Eagle Ford wells upon which this workflow is based. Then, we apply the workflow to the Utica-Point Pleasant Shale Play and compare those results to core measurements.
Histologic Changes in the Adrenal Gland Reflect Fetal Distress in Hydrops Fetalis
Authors: Taweevisit Mana , Atikankul Tawin , Thorner Paul Scott
Published: August 2013

The distribution of lipid in the fetal adrenal cortex is reported to correlate with the duration of hypoxia and degree of fetal stress. The original studies were based on Oil Red O staining, requiring frozen tissue that is often not available. To investigate the reliability of these observations, the distribution of lipid in the fetal adrenal cortex was studied in hydrops fetalis (HF) of different etiologies, using immunostaining for adipophilin on formalin-fixed material. Twenty cases of HF due to hemoglobin (Hb) Bart were compared to 34 cases of HF due to other causes. In the fetal zone, lipid distribution was more diffuse in Hb Bart HF compared to other causes of HF, including those due to anemia, supporting the concept that increased lipid in the fetal zone is associated with severity of hypoxia. A more diffuse distribution of lipid correlated with adrenal cytomegaly ( P < 0.01) and extramedullary hematopoiesis ( P < 0.01) but not Hb level ( P = 0.68) nor compact cell change ( P = 0.7) or cystic degeneration ( P = 0.07) in the definitive zone. A greater degree of cystic degeneration correlated with lower gestational age, rather than the specific etiology of HF. Thus, cystic degeneration is more a reflection of the onset of fetal stress than severity. The combined histologic changes in the fetal and definitive zones of the adrenal gland provide complementary information about fetal status in HF. Immnunostaining for adipophilin circumvents the need for frozen tissue for assessing lipid content by Oil Red O staining, facilitating studies based on archival material.
Consumer Hypnotic-Like Suggestibility: Possible Mechanism in Compulsive Purchasing
Authors: Prete M. Irene , Guido Gianluigi , Pichierri Marco
Published: August 2013

The authors hypothesize a concept, Consumer Hypnotic-Like Suggestibility (CHLS), defined as an altered state of consciousness, as a state causing a tendency to respond positively to messages aimed at inducing consumers to make unplanned purchases. This study aims to investigate the associations of CHLS with interpersonal variables and compulsive purchasing—a frequent and uncontrollable preoccupation with buying or impulses to buy. A study was conducted on a sample of 232 subjects ( n = 111 men; M age = 41 yr.), through the administration of a questionnaire, which measured: CHLS, compulsive purchasing, consumer susceptibility to interpersonal influence (the necessity to enhance one's image in the opinion of others through the consumption of products), and consumer atmospherics, i.e., environmental stimuli known to influence purchasing decisions. Modeling and mediation analyses suggested that internal and external drivers—Consumer Susceptibility to Interpersonal Influence and atmospherics—are positively related to CHLS which affects compulsive purchasing.
Materialism and Addictive Buying in Women: The Mediating Role of Anxiety and Depression
Authors: Otero-López José Manuel , Villardefrancos Estíbaliz
Published: August 2013

There is empirical evidence regarding the interrelationships between materialism, negative emotions, and addictive buying. The aim of this study was to clarify the direction of the relationships among these variables. Specifically, the main objective was to explore the possible mediating roles of anxiety and depression in the link between materialism and addictive buying. Path analysis results, using a sample of 685 women, generally supported the suitability of the proposed model in which anxiety and depression mediated the effects of the materialism dimensions, “importance” and “success,” on addictive buying, and that depression also mediates the influence of the “importance” and “happiness” dimensions. Moreover, a direct effect of the importance dimension on addictive buying was found.
Effects of Approach-Avoidance Training on Implicit and Explicit Evaluations of Neutral, Angry, and Smiling Face Stimuli
Authors: Woud Marcella L. , Becker Eni S. , Lange Wolf-Gero , Rinck Mike
Published: August 2013

A growing body of evidence shows that the prolonged execution of approach movements towards stimuli and avoidance movements away from them affects their evaluation. However, there has been no systematic investigation of such training effects. Therefore, the present study compared approach-avoidance training effects on various valenced representations of one neutral (Experiment 1, N = 85), angry (Experiment 2, N = 87), or smiling facial expressions (Experiment 3, N = 89). The face stimuli were shown on a computer screen, and by means of a joystick, participants pulled half of the faces closer (positive approach movement), and pushed the other half away (negative avoidance movement). Only implicit evaluations of neutral-expression were affected by the training procedure. The boundary conditions of such approach-avoidance training effects are discussed.
Physicochemical fractionation of americium, thorium, and uranium in Chernozem soil after sharp temperature change and soil drought
Authors: Kovacheva Petya , Mitsiev Svilen , Djingova Rumyana
Published: August 2013

A sequential extraction procedure was used to study the changes in the physicochemical forms of americium (Am), thorium (Th), and uranium (U) in laboratory-contaminated Chernozem soil as a result of sharp variations of the environmental temperature and soil moisture. The influence of freezing and soil drought on the radio-ecological hazard was evaluated three months after radioactive contamination with aqueous solutions of 241Am, 234Th, and U. The subsequent changes in the physicochemical forms of the actinides, caused by sharp increases in the environmental temperature and soil moisture, were examined for one month. The data showed that continuous freezing increased the potentially mobile forms of Am and Th but had the opposite effect on U. Prolonged soil drought did not influence the fractionation of Am and Th but led to the redistribution of U between the carbonates and organic matter and caused its immobilisation. The sharp increase in the temperature of the frozen soil caused the immobilisation of Am and Th and increased the potential mobility of U. The warming and enhanced humidity of the dry soil led to the immobilisation of Am and redistribution of U between the soil phases.
Classmates With Disabilities and Students’ Noncognitive Outcomes
Authors: Gottfried Michael A.
Published: August 2013

The increasing trend of placing students with disabilities in general education classrooms has raised questions among researchers, policymakers, practitioners, and parents about classmate peer effects on all students. However, little is known about the peer effects of classmates with disabilities on the outcomes of other students in the classroom; no research has evaluated these peer effects on other students’ noncognitive outcomes though they are highly predictive of schooling and lifelong success. The purpose of this study is to fill this research gap by using quasi-experimental methods on a nationally representative data set (i.e., Early Childhood Longitudinal Study–Kindergarten Class) of elementary school students to examine the peer effects of classmates with disabilities on five noncognitive scales for classmates without disabilities. The findings indicate that students with a greater number of classmates with disabilities have higher externalizing and internalizing behavioral problems and lower frequencies of self-control, approaches to learning, and interpersonal skills. The findings are differentiated by disability category of a student’s classmates and are moderated by individual and contextual factors. Implications for policy and practice are addressed.
Elementary School Interventions
Authors: Hemelt Steven W. , Roth Kimberly B. , Eaton William W.
Published: August 2013

This study exploits a randomized trial of two light-touch elementary school interventions to estimate long-run impacts on postsecondary attendance and attainment. The first is a classroom management technique for developing behavioral skills in children. The second is a curricular intervention aimed at improving students’ core reading skills. We detect no average impact of either intervention on the likelihood of college enrollment or degree receipt, but find heterogeneous effects by student gender and initial level of academic achievement. Assignment to the behavioral intervention increases the likelihood of college attendance for females, especially at 2-year institutions, but has little impact on males. We find suggestive evidence that exposure to the behavioral intervention benefits low-performing students more than high-performers, whereas exposure to the curricular intervention influences college outcomes more for middle- to high-performing students.
Guidelines for Selection and Use of Coarse Recycled-Concrete Aggregates in Structural Concrete
Authors: Butler Liam , Tighe Susan L. , West Jeffrey S.
Published: August 2013

This paper presents guidelines for using recycled-concrete aggregate (RCA) as a full or partial replacement for natural coarse aggregate in new concrete (RCA concrete). Several international standards and guidelines for the use of RCA in concrete are reviewed and contrasted to identify areas in which further development is required. The main results of an extensive experimental research program by the authors are summarized here to provide a basis for the development of a framework for using RCA in structural concrete. Several RCA performance classes are proposed, each with a specific set of requirements and suitable applications. The proposed performance classes define further requirements and guidance for the use of RCA beyond the requirements of Canadian Standards Association A23.1 and ASTM C33. The authors propose a detailed decision tree to allow engineers, concrete producers, aggregate suppliers, and contractors to assess whether a particular RCA source is suitable for use in reinforced concrete or plain concrete or as fill material.
Blast Furnace Slag as Sustainable Material in Concrete Pavements
Authors: Jahangirnejad Shervin , Van Dam Thomas , Morian Dennis , Smith Kurt , Perera Rohan , Tyson Samuel
Published: August 2013

Slag materials are byproducts of metallurgical processes that include metal production from ore and refinement of impure metals. Air-cooled blast furnace slag (ACBFS) has been used for different pavement-related applications. Appropriate use of ACBFS can significantly enhance sustainability, rather than disposing of it, by effectively contributing to all aspects of the “triple bottom line.” Proper use of ACBFS can also result in economic, environmental, and social benefits as long as the performance of the concrete structure is not compromised through such use because any short-term economic and environmental gain would be rapidly eclipsed by the economic, environmental, and social costs of poor pavement performance. Thus, it is essential that engineers and contractors who use ACBFS aggregates in concrete understand its unique properties to make sure that the expected performance of the pavement over its design life is achieved. The chemical composition of ACBFS may affect its performance and has to be considered when ACBFS is used as a coarse aggregate. Physical properties of ACBFS, such as texture, absorption, and specific gravity, also have to be considered when ACBFS is used in concrete. ACBFS also affects fresh and hardened properties of concrete. Specific design, construction, and quality control considerations have to be taken into account when ACBFS is used. In this paper, sustainability aspects of using ACBFS as a coarse aggregate in concrete pavements and considerations for its use in this application are presented. A best practices guideline recently published by FHWA presents the same discussions in more detail.
Improving Properties of Reclaimed Asphalt Pavement for Roadway Base Applications through Blending and Chemical Stabilization
Authors: Bleakley Albert M. , Cosentino Paul J.
Published: August 2013

Finding innovative ways to incorporate reclaimed asphalt pavement (RAP) into highway base course applications will provide both environmental and economic benefits by allowing in situ recycling of material for projects such as widening or shoulder addition. RAP is a well-drained granular material; however, 100% RAP has low bearing strength and creeps under load. The objective of this research is to develop methods to improve RAP's strength while reducing creep to an acceptable level through blending with high-quality crushed-limestone aggregate, by chemical stabilization with asphalt emulsion or portland cement, or both. RAP–aggregate blends with and without chemical stabilization were compacted by the modified Proctor method, cured, and tested for strength and creep. Strength was tested by the limerock bearing ratio (LBR), a variant of the California bearing ratio test. Specimens were tested dry and soaked to evaluate retained strength. One-dimensional creep testing was performed with 7-day oedometer tests. RAP–aggregate blends have the potential to be used successfully as base course material. Blends of RAP with 50% limerock base material attained acceptable LBR strength and creep with the addition of 1% of either asphalt emulsion or cement. Blends of RAP with 75% or more limerock attained close-to-acceptable LBR and low levels of creep without any chemical stabilizer. Significant variability was noted between results with different blends and stabilizing agents. Performance testing should be conducted to establish the suitability of a specific RAP–aggregate blend.
Evaluation of Aggregate Imaging Techniques for Quantification of Morphological Characteristics
Authors: Wang Linbing , Sun Wenjuan , Tutumluer Erol , Druta Cristian
Published: August 2013

Aggregate morphological characteristics, including shape, angularity, and surface texture, have a significant impact on the engineering properties of construction materials such as hot-mix asphalt and hydraulic cement concrete. Consequently, the quantification of morphological characteristics of aggregates is essential for quality control of both aggregate production and pavement construction. Imaging techniques provide a cost-effective means for measuring the aggregate morphological characteristics conveniently without tedious work. However, these imaging techniques adopt various mathematical methods with different instrument setups and result in different definitions of morphological descriptors that are usually incomparable with each other. This paper evaluates prevalent imaging techniques used for aggregate morphological characteristics analysis, including equipment cost, repeatability, reliability, accuracy, and measured morphological parameters. Three imaging techniques (second-generation Aggregate Imaging Measurement System, first-generation University of Illinois aggregate image analyzer, and Fourier transform interferometer system), are further evaluated by comparing the analysis results of seven types of aggregates passing a ¾-in. sieve and retained on a ½-in. sieve with manual measurements and visual rankings. Analysis of variance between measurements using different methods is also conducted to evaluate the accuracy of each aggregate imaging system. From the data analysis, recommendations that depend on morphological characteristics of most interest to engineers are made for the selection of appropriate imaging-analysis techniques.
Evaluation of Aggregate Size and Shape by Means of Segmentation Techniques and Aggregate Image Processing Algorithms
Authors: Moaveni Maziar , Wang Shengnan , Hart John M. , Tutumluer Erol , Ahuja Narendra
Published: August 2013

Morphological properties of mineral aggregates are known to affect pavement and railroad track mechanistic behavior and performance significantly in relation to strength, modulus, and permanent deformation. With imaging technology, an objective and accurate measurement of aggregate particle size and shape properties can be obtained in a rapid, reliable, and automated fashion. But these advances in aggregate imaging must be brought to project sites and quarries in the field. This paper introduces field image-acquisition and image-processing techniques for extraction and analyses of size and shape properties of individual aggregate particles. Referred to as segmentation techniques, image-processing methods developed in this study analyzed two-dimensional field images of aggregates captured by a digital single-lens reflex camera. The segmented aggregate images were fed into the validated University of Illinois aggregate image analyzer to quantify particle size and shape properties by means of its image-processing algorithms for flat-and-elongated ratio, angularity index, and surface texture index. The developed method successfully determined the properties of coarse-aggregate samples collected from various depths in a layer of railroad track ballast. The promising preliminary results indicate that these segmentation techniques could be considered in the field for capturing several aggregate particles rapidly and reliably in a single image so that (a) size and shape properties of individual particles could be analyzed and (b) both spatial property variability and property changes with layer depth and usage (i.e., property degradation in time) could be evaluated under service loading.
Analytical and Laser Scanning Techniques to Determine Shape Properties of Aggregates
Authors: Komba Julius J. , Anochie-Boateng Joseph K. , van der Merwe Steyn Wyand
Published: August 2013

The fundamental shape attributes of aggregates used in pavements (i.e., form, angularity, and surface texture) have not been accurately quantified historically because of their irregular and nonideal shapes. This paper presents selected results from the use of a laser-based scanning technique to determine the form of aggregates employed in construction of pavements in South Africa. A three-dimensional (3-D) laser scanning system was used to examine aggregate materials from various sources, and the data were processed to reconstruct 3-D models of the aggregate particles. The models were further analyzed to determine the properties of the forms. Two analysis approaches based on physical properties of the aggregate and spherical harmonic analysis were employed to determine the form indices, and the results were compared. The indices based on the physical properties included (a) sphericity computed from the surface area and volume, (b) sphericity computed from three orthogonal dimensions, and (c) the flat-and-elongated ratio computed from the longest and shortest dimensions of an aggregate particle. Good correlations were observed between the form indices from the aggregate physical properties and the spherical harmonic form index. One conclusion of the research is that the laser scanning technique can be employed to quantify better the form properties of aggregate materials used in pavements.
Assessment of Scour on Bridge Foundations by Means of in Situ Erosion Evaluation Probe
Authors: Kayser Mohammad , Gabr Mohammed A.
Published: August 2013

The work in this paper presents the use of an in situ erosion evaluation probe (ISEEP) to assess scour depth at bridge piers. Numerical modeling and deployment of the device at a North Carolina Outer Banks site damaged by Hurricane Irene in 2011 demonstrates the applicability of the proposed concept. Computational fluid dynamics software, FLOW-3D, was used to assess the scour depth at a bridge pier, and the results were compared with values based on ISEEP-estimated parameters by using an excess-stream power model. The scour depth was also calculated from empirical equations that assumed the same conditions as those used in the numerical analysis. Parametric analysis using FLOW-3D indicated that of the parameters for defining the scour depth, the entrainment coefficient had the largest effect, whereas the drag coefficient had the smallest effect on the scour magnitude within the range of values included in this analysis. The estimated scour depths that were based on ISEEP data agreed relatively well with the scour magnitudes obtained from the numerical analysis, as the ISEEP data reflected the changes in the properties of the sand layer with depth. In contrast, the scour magnitude calculated from the empirical equations underestimated the scour depth, mainly because these equations had no provision for a layered-soil profile. Further validation of both the field-testing procedure and the data reduction approach, including the assessment of the applicability in soils that contain an appreciable percentage of fines, is recommended.
Measuring Shear Wave Velocity in Laboratory to Link Small- and Large-Strain Behavior of Soils
Authors: Guadalupe Yaurel , Baxter Christopher D. P. , Sharma M. S. Ravi
Published: August 2013

Current geotechnical practice relies on empirical relationships with in situ tests to determine the effective stress strength parameters for dense, cohesionless soils. Although these methods work reasonably well in practice, they cannot account for in situ effects related to time, fabric, and cementation. These factors are especially important for brittle or sensitive soils, such as loess and cemented sands. To develop methods that can predict strength in these types of soils, a better understanding of the link between small- and large-strain behavior is needed. The objective of this paper is to evaluate the hypothesis that a unique relationship exists between the small-strain shear modulus (G0) and the effective stresses at failure (σ'1f) for dilatant soils. To accomplish this objective, isotropically consolidated–drained triaxial compression tests were performed, with shear wave velocity measured throughout the tests. The soils tested in this study included a quartz sand and nonplastic silt, and the results were compared with previous studies by the authors on weakly cemented sands. The findings showed that the G0/σ'1f ratio was approximately 200 6 20 for the three soils tested and was independent of density, degree of cementation, and confining stress. If true for other soils, this finding could have important implications for evaluating staged construction on sensitive soils and estimating the strength of dilative soils in situ.
Evaluating Laboratory Compaction Techniques of Reclaimed Asphalt Pavement
Authors: Cosentino Paul J. , Bleakley Albert M. , Sajjadi Amir M. , Petersen Andrew J.
Published: August 2013

Reclaimed asphalt pavement (RAP) is a byproduct of roadway resurfacing. A limited amount of RAP can be recycled into new hot-mix asphalt; the rest is stockpiled. Some states allow the use of RAP–aggregate blends as base course material. Because of RAP's low strength and susceptibility to creep deformation, the Florida Department of Transportation (DOT) excludes RAP from being used as pavement base course for high-traffic areas. The research objective was to determine whether the strength characteristics of RAP could be improved through compaction and thereby make its base suitable in high-traffic areas. Modified Proctor, vibratory, and gyratory compaction data were compared. Four RAP sources were used. Specimens compacted by the three methods were tested with the limerock bearing ratio (LBR), unconfined compressive strength, and indirect split tensile strength. LBR is Florida's variation of the California bearing ratio. Specimens were compacted to either a density or a compaction energy level. Vibratory compaction produced the lowest densities and strengths. Modified Proctor produced higher densities and strengths than vibratory, but the LBR strengths for all RAP types were consistently below Florida DOT standards. Gyratory compaction produced the highest densities and strengths. Gyratory RAP specimens were two to four times as strong as modified Proctor specimens at the same density. The compaction method did not have as significant an effect on creep, although gyratory-compacted samples produced less creep than modified Proctor–compacted samples.
Microstructural Analysis for Mechanical Behavior of Granular Waste Materials
Authors: Ahmed Abdelkader T.
Published: August 2013

Many granular waste and recycling materials are being considered as substitutes for natural aggregates in construction applications. Incinerator bottom ash waste (IBAW), a residue from burning household waste, was previously landfilled, but now two-thirds of this ash is recycled, primarily in road construction. In this study, IBAW was mixed with limestone to produce a blend with acceptable properties for use as a road foundation layer. Cement was added to the blends to improve their mechanical characteristics. Scanning electron microscopy (SEM) was used to study the physical and chemical features of untreated and cement-treated IBAW blends and to identify the nature of the materials and any secondary reaction elements, especially after mixing with water. The micromechanical behavior of limestone–IBAW blends under uniaxial compression stresses was modeled on the basis of SEM images of the blends' microstructures. The results of micromodeling in general matched the experimental data very well. Microstructure modeling proved the high stiffness of the cement-treated blends. The material behavior in the plastic stage changed significantly with a change in the geometry and stiffness of the inclusions. Experimental and modeling results also showed that IBAW material behaved as a conventional aggregate. Results demonstrated in general that microstructural analysis was quite useful in describing the mechanical behavior of IBAW and could be applied to all granular waste materials.
Moisture-Sensitive and Stress-Dependent Behavior of Unbound Pavement Materials from in Situ Falling Weight Deflectometer Tests
Authors: Salour Farhad , Erlingsson Sigurdur
Published: August 2013

In an instrumented flexible pavement with a subsurface drainage system, a field study was performed to investigate the influence of water on the response of the pavement structure. The drainage system of the structure was clogged for 3 months; this condition allowed the groundwater to rise and the structure to undergo high moisture conditions. Reopening of the drainage system permitted the structure to approach its previous draining hydrological state. Along with monitoring of subsurface groundwater level and moisture content, the structural response of the pavement was studied by conducting frequent falling weight deflectometer tests with multilevel loads. The stress sensitivity of the unbound layers and the influence of moisture on their stiffness were studied, with the intent of using the data to determine the unbound materials' nonlinear parameters through a backcalculation algorithm. The groundwater level rose rapidly after the drainage system was clogged. This rise in groundwater level significantly affected the overall stiffness of the pavement structure, and the backcalculated stiffness of the unbound layers decreased as their moisture content increased. Furthermore, the unbound layers exhibited stress-dependent behavior to multilevel loads. The subgrade showed a stress-softening response in an unsaturated condition and stress-independent behavior in a saturated state. The granular layer exhibited stress-hardening behavior. Backcalculation of the unbound nonlinear parameters determined by the universal extended k–θ model revealed that the k1 parameter decreased with increasing moisture content for both the unbound granular layer and the unsaturated fine-grained subgrade material.
Temporal Variation of Bird Assemblages in a Wetland: Influence of Spatial Heterogeneity
Authors: Ronchi-Virgolini Ana L. , Lorenzón Rodrigo E. , Blake John G. , Beltzer Adolfo H.
Published: August 2013

The temporal variation of bird assemblages at three sites within a wetland of the Parana River was examined. The aim was to obtain an overview of the influence of spatial heterogeneity on communities in such a variable environment as the wetlands. We recorded 1,662 individuals belonging to 139 species from 40 families. There were no significant differences between sites in richness, abundance nor diversity. Species richness in the first year was greater than during the second year. Number of resident and migrant species decreased in the second year. Community composition differed between the two years of study and was significantly different among seasons. Species were grouped into 19 trophic guilds. In this study, number of species and their abundances were not significantly different among sites; there were differences in the composition of birds among sites. Thus, the structure of the environments influenced the composition of assemblages in different areas. Guild composition remained fairly constant between years and among seasons. Geomorphological and hydrological dynamics of the river produce a heterogeneous availability of habitats and resources that affect the composition of bird assemblages. Annual and seasonal changes in meteorological variables can lead to changes in the structure and/or composition of those assemblages.
The Effect of Monochromatic and Mixed LED Light Colour on the Behaviour and Fear Responses of Broiler Chicken
Authors: Sultana Shabiha , Hassan Md. Rakibul , Choe Ho Sung , Ryu Kyeong Seon
Published: August 2013

This study observed the effect of different LED light colour on the behaviour and fear responses of broilers. In experiment 1, 400 broilers were placed into eight different light treatments. In experiment 2, six different light colours with five different age groups were considered. In experiment 1, use of a red and red–yellow mixed light significantly increased walking behaviour. Consequently, sitting and standing behaviour were found to be wavelength dependent, whereby short wavelength (blue, green–blue) treated birds spent more time sitting and standing than that under long wavelength (red, red–yellow). Consistently in experiment 2, birds spent more time feeding under the green treatment than with other treatments. Walking behaviour was significantly decreased and sitting and standing behaviour was increased under the blue light. Age also influenced the behaviour of broiler: young birds were more active than older birds. In addition, ground pecking and wing stretching behaviour were influenced by the wavelength of the light. Time of day did not influence the behaviour of the broilers. Under the red and red–yellow light treatments, birds spent longer in tonic immobility. Thus, the results suggest that red and red–yellow light activated the broiler's movement and fear responses while blue and green-blue decreased the movement and they spent more time sitting.
Sex Determination of Duck Embryos: Observations on Syrinx Development
Authors: Wilson Robert E. , Sonsthagen Sarah A. , Franson J. Christian
Published: August 2013

Ducks exhibit sexual dimorphism in vocal anatomy. Asymmetrical ossification of the syrinx ( bulla syringealis) is discernable at about 10 days of age in male Pekin duck ( Anas platyrhynchos domestica) embryos, but information is lacking on the early development of the bulla in wild ducks. To evaluate the reliability of this characteristic for sexing developing embryos, we examined the syrinx of dead embryos and compared results with molecular sexing techniques in high arctic nesting Common Eiders ( Somateria mollissima). Embryos 8 days or older were accurately (100%) sexed based on the presence/absence of a bulla, 2 days earlier than Pekin duck. The use of the tracheal bulla can be a valuable technique when sex identification of embryos or young ducklings is required.
Use of an AG Microsatellite to Characterise Alectoris Species
Authors: Ansón J.A. , Savva D. , Arruga M.V.
Published: August 2013

The red-legged partridge ( Alectoris rufa) is normally found in the Iberian Peninsula, southern France and some points of northern Italy and southern England. A number of factors have drastically reduced the number of wild red-legged partridges in these areas. It is necessary to know their genetic situation and to identify different populations and species. Microsatellite markers are very effective genetic markers. In order to identify microsatellite markers in this species to gain genetic knowledge of their populations, DNA was cleaved partially with AluI and ligated in plasmid pSMART; this was inserted in Escherichia coli to obtain a whole genome library. This library was screened by amplifying with the polymerase chain reaction and then sequencing the A. rufa DNA in plasmids isolated from colonies selected at random. Some of the sequenced PCR products were found to contain possible microsatellite sequences and two of these were used to characterise four different species of Alectoris. One of these sequences (GTTTT) was always found to be repeated three times but the number of repeats of the second one (AG) was found to vary between species. Therefore, the (AG)n microsatellite may be a good candidate to distinguish between species of the genre Alectoris.
The Relationship between Environmental Factors and Flamingo Aggression Examined via Internet Resources
Authors: Peluso Alicia I. , Royer Erica A. , Wall Matthew J. , Anderson Matthew J.
Published: August 2013

This study sought to examine the relationship between weather and aggression in Caribbean flamingos by utilising a novel observation method. Previous research has shown evidence of increased levels of aggression during periods of warmer weather in a wide range of species including humans. We observed the captive flock of Caribbean flamingos at the Smithsonian National Zoological Park (Washington, DC, USA) by means of a web cam, and correlated the observed instances of aggression with eight different weather variables gathered via www.weather.com . Results evidenced significant positive correlations between aggression and several variables including: temperature [ r (38) = 0.31, P = 0.048], “feels like” [ r (38) = 0.31, P = 0.049], and UV-index [ r (38) = 0.35, P = 0.025]; and a multiple linear regression (stepwise) suggested that UV-index is a significant predictor of aggressive instances, thus highlighting the relationship between such environmental factors and flamingo aggression. Evidence has been found of a relationships between UV light and aggression in other species, and the results of the present study suggest a similar relationship in flamingos. Employing webcams may allow researchers to obtain larger samples to be included in the study of aggression or to examine this and other behaviors in a wider variety of captive animals.
Hormone Levels in the Outer Layer of Domestic Goose (Anser Anser Domesticus) Eggs Change Over the Laying Season
Authors: Kent John P. , Murphy Kenneth J. , Salamon Attila , Hayden Thomas J. , Möstl Erich
Published: August 2013

In general, avian species produce clutches of more than one egg. Differential investment in egg weight and hormone levels is possible and their effects on development and behaviour can be measured. Here we investigated changes in three hormones (testosterone, T; androstenedione, A4 and progesterone, P4) in the outer layer of yolks of infertile domestic goose eggs over the course of a laying season. There was a significant change in the concentration of all three hormones: T and P4 increased in a linear manner across the season whilst A4 increased until mid season and then steadily decreased. The correlation between T and P4 (r =0.613, P < 0.001), and between T and A4 (r = 0.746, P < 0.001) were both positive, but the relationship between A4 and P4, while positive was not strong (r = 0.379, P < 0.001), although still significant. The increase in P4 over the laying season is consistent with the transition from a laying to a broody state. The increase in T is consistent with a trade-off for the seasonal decline in egg weight.
Effects of Formic Acid Administration in the Drinking Water on Production Performance, Egg Quality and Immune System in Layers during hot Season
Authors: Abbas Ghulam , Khan Sohail Hassan , Rehman Habib-ur
Published: August 2013

The objective of this study was to determine the effects of formic acid on egg production, egg weight, feed conversion ratio, egg quality and immunity in commercial layer reared during the hot season. In this study, 360 Hy-Line W-98 commercial White Leghorn, 68-week old hens were randomly assigned into four groups. The first group (control) continued receiving normal drinking water and other three groups consumed drinking water containing formic acid at levels of 0.5, 1.0 and 1.5 mL L−1. The results showed that the laying hens that consumed drinking water with formic acid had greater egg production, egg weight and egg mass than the control. Similarly, feed conversion improved with the administration of formic acid in water. Haugh units, egg shell thickness and egg grading from hens consuming acidified water containing 1.0 or 1.5 mL L−1 were significantly greater than those from the control group. Formic acid had no effect on yolk colour. In addition, the geometric means HI titres against Newcastle disease of birds consuming water containing formic acid were higher on all sampling days than those consuming water without acid. This study showed that formic acid at levels of 1.0 or 1.5 mL L−1 positively influences egg production, egg weight, shell quality, egg grading and enhances the immunity in older commercial layers during the hot season.
Fundamental Principles of Cryobiology and Application to Ex situ Conservation of Avian Species
Authors: Liu Jianan , Cheng Kimberly M. , Silversides Frederick G.
Published: August 2013

Cryopreservation of animal germplasm is an important ex situ conservation strategy. Germplasm can be preserved at subzero temperatures and recovered in a way that allows germline development to be resumed at a later time. This strategy is routinely used for genetic improvement of dairy cattle, maintenance of lab strains of rodents and in human reproductive medication, and it contributes to genetic conservation of a growing number of wild mammalian species. Although there is an urgent need, cryoconservation of germplasm for birds is limited, partly because of skepticism with respect to the effectiveness of cryopreservation techniques. An understanding of fundamental principles of cryobiology and comparative cryobiological and physiological properties of germplasm is essential to the development and optimisation of cryopreservation protocols. In mammals, slow freezing has been used to cryopreserve gametes and embryos but the effectiveness of slow freezing is specific to the cell type and it does not protect extracellular structures. Vitrification, which is a process of solidification without crystallisation, can be used to effectively preserve multicellular structures such as gonadal tissue. In some domestic and wild avian species, the fertility produced by cryopreserved semen is sufficient for conservation but the w chromosome is lost. Avian eggs and embryos cannot be cryopreserved, but gonadal tissue can be cryopreserved and recovered by transplantation. Cryopreservation of germplasm allows ex situ conservation of avian species because it allows repopulation without the limitations of geographic isolation or reproductive longevity.
Houbara Bustard Hatching in Surrogate Chicken Albumen and Eggshell
Authors: Liu Chunhai , Kinne Jörg , Baskar Vijay , Guerineche Zhor , Wernery Ulrich , Chang Il-Kuk
Published: August 2013

The viability and hatchability of Houbara bustard ( Chlamydotis undulata) embryos were investigated in a surrogate (chicken) albumen and eggshell system. Egg yolk including embryos were separated from freshly laid Houbara bustard eggs, and cultured in albumen from chicken and Houbara, respectively. The viability of Houbara embryos after day 4 in the same sized chicken eggshell was 76.9% and 61.1% in chicken and Houbara albumen, respectively. The entire content (egg yolk with embryo and the surrogate albumen) were then transferred on day 4 into an eggshell of a larger double yolk chicken egg, and incubated for a further 19 days. On day 14, the viability of Houbara embryo in the surrogate Houbara and chicken albumen were 27.3%, and 57.1%, respectively. Two Houbara chicks hatched successfully from the chicken albumen (7.7%), while one hatched from the Houbara albumen (5.6%). The results showed that Houbara embryo could develop to hatching in chicken albumen and eggshell. This technology will provide a tool to hatch damaged eggs as well as soft-shelled egg of endangered wild birds.