bluuebunny/crossref_metadata_2025_split huggingface dataset:
Measurement of Uniformity and Anisotropy in Granular Materials
Authors: Muhunthan B , Masad E , Assaad A 
Published: February 2009

Abstract
A new apparatus to conduct impregnation of granular materials has been developed to facilitate specimen preparation for microstructure observations. New experimental and analytical procedures have been presented to quantify the nonuniformity and anisotropy of granular materials. The nonuniformity of porosity distribution within a specimen was evaluated using imaging techniques. The anisotropy analysis consisted of the directional distribution of local porosity and orientation of solids and voids.
The procedures have been used to study the fabric of granular specimens prepared from Ottawa sand, silica sand, and spherical glass beads. The relation between directional porosity and the preferred orientation of granular particles and voids was found to be highly dependent on their angularity and elongation.
Explosive Induced Pore Pressure in a Sandfill Dam
Authors: Charlie WA , Lewis WA , Doehring DO 
Published: February 2009

Abstract
This paper reports on the potential performance of earthfill and tailings dams, and other saturated earthen structures, subjected to blast vibrations. Relationships between explosive-induced residual pore pressure increase and crest settlement versus peak particle velocity are presented. Eight explosive tests, conducted on a 2.25-m-high dam constructed of loose dilative sand, showed that significant increases in residual pore pressure (PPR &gt; 0.1) occurred when peak particle velocity exceeded 0.015 m/s at shallow depths to 0.035 m/s at greater depths. Limited crest settlement occurred when the peak particle velocity exceeded 0.025 m/s. Results of this research, previous research, and the field behavior of full-scale earthfill and tailings dams indicate that peak particle velocity below 0.025 m/s and 0.10 m/s are reasonable thresholds to limit pore pressure buildup in full-size earthfill and tailings dams sensitive and not sensitive to vibrations, respectively.
Hydraulic Conductivity Testing of Geosynthetic Clay Liners (GCLs) Using the Constant Volume Method
Authors: Wang XD , Benson CH 
Published: February 2009

Abstract
Hydraulic conductivity tests were conducted using open and constant-volume permeation systems on specimens from a geosynthetic clay liner (GCL). Two constant volume (CV) systems were employed: the falling-head constant-volume (FHCV) system and the constant-head constant-volume (CHCV) system. A conventional burette system using pressurized air was employed for the open system (OS) tests. The test results show that hydraulic conductivity tests can be conducted 30 or more times faster with the FHCV and CHCV systems than with an open system. Typically the permeation portion of the FHCV and CHCV tests can be conducted in one-half day. Slightly lower hydraulic conductivities are measured with the CV systems due to the slightly higher effective stress applied during testing with these systems. The CHCV system has several advantages over the FHCV system, including minimizing initial transient behavior, constant applied effective stress during testing, and simpler calculations.
Capillary Flow in the Geotechnical Centrifuge
Authors: Lord AE 
Published: February 2009

Abstract
A “bundle of capillaries” approach is used to model unsaturated soils. Movement of fluid is approximated by employing a simple Poiseuille's capillary flow mathematical model. It is found that the centrifuge model flow time is 1/n2 times that for the pertinent prototype flow time. Here model acceleration = n × acceleration of gravity (i.e., a = ng). This result applies for: 1. Capillary rise at an arbitrary angle to the horizontal. 2. Horizontal capillary flow. 3. Downward capillary flow (infiltration) at an arbitrary angle. 4. Vertical drainage at an arbitrary angle.
This is the same centrifuge model scale factor as for advection, diffusion, and dispersion.
Clogging Phenomena of the Residual Soil-Geotextile Filter System
Authors: Lee I-M , Kim J-H , Reddi LN 
Published: February 2009

Abstract
Clogging tests on residual soil-geotextile filter systems were performed, and the permeability reduction due to clogging was evaluated. An extensive experimental program was performed using two typical weathered granite residual soils that were sampled at Shinnae-dong and Poi-dong areas in Seoul. Weathered granite residual soils, which are found in much of the Korean peninsula, pose unique challenges in terms of internal stability and filtration. Two separate simulation tests with weathered residual soils were performed: the cross-plane permittivity test (filtration) and the in-plane transmissivity test (drainage). Needle-punched non-woven geotextiles are selected since they are often used as drainage material in the field. The compatibility of residual soil-geotextile filter systems was investigated with emphasis on the clogging phenomenon. It was found that filter clogging was more significant in filtration than in drainage. The permeability reduction in the coarser Shinnae-dong soil-filter system was more serious than in the finer Poi-dong soil-filter system.
Influence of Procedural Variables on the Gradient Ratio Test
Authors: Fischer GR , Maré AD , Holtz RD 
Published: February 2009

Abstract
Ideally, filtration behavior of soil-geotextile systems as determined by the gradient ratio (GR) test (ASTM D 5101) should depend only on the soil and geotextile properties. In practice, however, test results can vary substantially with slight variations in test details and procedures. In addition, some optional procedures can have a significant effect on test results, while other required procedures appear to have little influence. A systematic study was performed to evaluate the effects of these procedures on GR test results. It was found that microfiltration of the in-flow water had a significant effect on filtration behavior. Chlorine algicide was effective in enhancing long-term filtration behavior, as was purging with CO2 and slow saturation of the system. Placement of the soil specimen also influenced GR values; they were found to be lower for compacted specimens than for loosely placed specimens. Presoaking geotextiles had no observable effect on filtration behavior, and disturbance of the GR device during the early stages of the test caused immediate and significant changes in permeability and GR.
Numerical Simulation of Water Movement in the Suction Equalization of a Thermal Conductivity Sensor
Authors: Shuai F , Fredlund DG , Samarasekera L 
Published: February 2009

Abstract
Laboratory and field measurements of soil suction using a thermal conductivity soil suction sensor involves installing the sensors into a soil mass. The sensors may be installed either in an initially wet or an initially dry state. In order to ensure a reliable suction measurement, it is important that the sensor reach suction equalization with the surrounding soil. The results of a numerical study have shown that, in most cases, the equalization time required for an initially dry sensor is less than the equalization time for an initially wet sensor. This difference is mainly due to the unsaturated zone that develops on the boundary of the initially wet sensor at the beginning of the drying process. The results of the numerical simulation have been substantiated by laboratory suction measurements.
Limiting Compression Curves
Authors: Sridharan A , Prakash K 
Published: February 2009

Abstract
Depending upon the initial water content of the soil sample, a family of compression curves is possible. Identification of characteristic limiting water contents for any fine grained soil system, along with the unique mechanisms controlling them, helps obtain the limiting compression curves. In the present note, it has been demonstrated that the compression curve obtained with its origin at the free swell limit of the soil represents the global upper bound compression curve, and that the compression curve obtained after the soil has reached equilibrium under cyclic consolidation represents the global lower bound compression curve. The compression curve obtained with its origin at the settling limit water content of the soil is the stress-free reference state curve as well as the upper bound compression curve for the homogeneous soil sample.
Sidewall Leakage in Hydraulic Conductivity Testing of Asphalt Concrete Specimens
Authors: Bowders JJ , Neupane D , Erik Loehr J 
Published: February 2009

Abstract
Asphalt specimens with irregular sidewalls can require special testing considerations when measuring hydraulic conductivity in a flexible wall permeameter. The hydraulic conductivity of laboratory prepared, dense asphalt concrete with high asphalt cement content (6–8.5% asphalt cement) was measured in the laboratory. Hydraulic conductivities were found to be excessive and were shown to be caused by sidewall leakage. Applying a thin layer of silicone vacuum grease to the sides of the asphalt specimens arrested the sidewall leakage, thereby permitting more accurate measurement of the hydraulic conductivity of the asphalt concrete.
Nonlinear Viscoelastic Properties of Bituminous Concretes
Authors: Sharma MG , Kim KS 
Published: February 2009

Abstract
Viscoelastic properties of bituminous concretes have been studied by observing creep behavior under a large range of compressive stress levels and temperatures. Effect of air void content on the creep properties has been observed. Results indicate that the test materials display linear viscoelastic properties only at low stress levels and temperatures. Master creep compliance curves corresponding to the linear range were obtained using the time-temperature shift hypothesis. The nonlinear creep behavior that is found to occur at higher stress levels and temperature has been characterized by the nonlinear viscoelasticity theory and the creep compliance functions based upon this theory were evaluated for the test materials. It is found that an increase in air void ratio leads to higher creep strains for a given stress level.
Preparation of Isotropically Consolidated Clay Samples with Random Fabrics
Authors: Edil TB , Krizek RJ 
Published: February 2009

Abstract
This paper describes equipment and procedures that can be employed to prepare clay samples with a highly random fabric and a known stress history. By appropriate choice of the clay mineral and proper control of pore fluid chemistry, high water content slurries can be consolidated isotropically to produce large size, relatively homogeneous samples for laboratory use in the study of fabric effects on clay behavior. The fabric of the resulting samples has been identified by the complementary use of scanning electron microscopy, optical microscopy, and X-ray diffractometry, and the isotropy in the mechanical response of specimens trimmed from the sample in perpendicular directions has been determined by consolidation tests, permeability tests, and consolidated-undrained triaxial compression tests. Comparisons in all cases have been made with analogous characteristics of specimens trimmed from anisotropically consolidated samples with a highly oriented fabric, and results have indicated that fabric effects can be significant in some cases.
Statistical Tolerance Limits for Censored Log-Normal Data
Authors: Little RE 
Published: February 2009

Abstract
A-basis and B-basis statistical tolerance limit computations are given for Type II failure censored log-normal data. The statistical tolerance limits are established by using factors given by Nelson and Schmee in conjunction with the best linear unbiased estimates for the normal distribution based on the coefficients tabulated by Sarhan and Greenberg. These tolerance limit computations complement analogous computations based on the Weibull distribution which have been illustrated in a recent tutorial paper by Little.
Evaluation of the Three-Component Model for Representing Wide-Range Fatigue Crack Growth Rate Data
Authors: Saxena A , Hudak SJ 
Published: February 2009

Abstract
The three-component model for representing wide-range fatigue crack growth rate (FCGR) behavior is evaluated by using a standard data set containing data at several load ratios on a 2219-T851 aluminum alloy. It is shown that this model can be used to model FCGR data accurately. The predicted fatigue lives for two geometries were obtained by integrating the fitted FCGR curves. These results compared well with the observed lives. Also, it was shown that the model has the flexibility to represent complex effects of load ratio over a wide range of load ratio and crack growth rate. This ability to interpolate easily between load ratios and to provide accurate fatigue life predictions makes the model an asset to design and reliability analyses.
The Effect of Interference on the Dimpled, Loaded-Hole Fatigue Strength of 2024-T3 Alclad® Aluminum Alloy
Authors: Kuc AP , Shewchuk J 
Published: February 2009

Abstract
The effect of interference fit on the fatigue strength of loaded holes is well known. Recently a new technique has been developed for increasing this strength in thin sheet material. The technique consists of dimpling the material centering about the region where the hole is to be made and thus introducing tensile plastic strain. The dimple is then flattened and the hole drilled, leaving the region around the hole under residual compressive stress. Experiments were carried out to obtain the combined effect of interference and dimpling in loaded-hole fatigue applications. In zero-totension fatigue tests on nominally 1.60-mm (0.063-in.) thick 2024-T3 Alclad® aluminum alloy specimens, combined optimum tapered-pin interference and dimpling gave a fatigue strength improvement factor of 4.0 while the dimpling technique increased the fatigue strength by a factor of 2.85 at 106 cycles to failure.
Strain-Dependent Differences in Several Reproductive Traits Are Not Accompanied by Early Postmating Transcriptome Changes in Female Drosophila melanogaster
Authors: McGraw Lisa A , Gibson Greg , Clark Andrew G , Wolfner Mariana F 
Published: February 2009

Abstract
Upon mating, Drosophila melanogaster females undergo numerous alterations in their behavior and reproductive physiology that are accompanied by small-magnitude transcript-level changes in up to 1700 genes. Many of these postmating transcriptome changes are the direct result of the sperm and seminal fluid proteins (Acps) that females receive from their mates. To begin to determine if the genetic background of the female's mate contributes to the previously described gene expression changes, we assessed whether interactions between the genotypes of two commonly used laboratory strains of D. melanogaster (Canton-S and Oregon R) influence the female's postmating transcriptome as well as several pre- and postcopulatory phenotypes. We find negligible differences in the female's transcriptome at 1–3 hr postmating regardless of the strain of the male with whom she mated. However, a male × female genotype interaction significantly influenced mate selection, and, in some cases, fecundity, fertility, and hatchability. Our data support previous work suggesting that many of the early postmating changes observed in D. melanogaster females are not caused by large modifications of transcript levels. Instead, early postmating phenotypes result from preexisting receptors or pathways that are already in place upon sexual maturity.
Alternative Induction of Meiotic Recombination From Single-Base Lesions of DNA Deaminases
Authors: Pauklin Siim , Burkert Julia S , Martin Julie , Osman Fekret , Weller Sandra , Boulton Simon J , Whitby Matthew C , Petersen-Mahrt Svend K 
Published: February 2009

AbstractMeiotic recombination enhances genetic diversity as well as ensures proper segregation of homologous chromosomes, requiring Spo11-initiated double-strand breaks (DSBs). DNA deaminases act on regions of single-stranded DNA and deaminate cytosine to uracil (dU). In the immunoglobulin locus, this lesion will initiate point mutations, gene conversion, and DNA recombination. To begin to delineate the effect of induced base lesions on meiosis, we analyzed the effect of expressing DNA deaminases (activation-induced deaminase, AID, and APOBEC3C) in germ cells. We show that meiotic dU:dG lesions can partially rescue a spo11Δ phenotype in yeast and worm. In rec12 Schizosaccharomyces pombe, AID expression increased proper chromosome segregation, thereby enhancing spore viability, and induced low-frequency meiotic crossovers. Expression of AID in the germ cells of Caenorhabditis elegans spo-11 induced meiotic RAD-51 foci formation and chromosomal bivalency and segregation, as well as an increase in viability. RNAi experiments showed that this rescue was dependent on uracil DNA-glycosylase (Ung). Furthermore, unlike ionizing radiation-induced spo-11 rescue, AID expression did not induce large numbers of DSBs during the rescue. This suggests that the products of DNA deamination and base excision repair, such as uracil, an abasic site, or a single-stranded nick, are sufficient to initiate and alter meiotic recombination in uni- and multicellular organisms.
Maternal Origin and Migratory History of Steelhead and Rainbow Trout Captured in Rivers of the Central Valley, California
Authors: Zimmerman Christian E. , Edwards George W. , Perry Kathleen 
Published: February 2009

AbstractSteelhead Oncorhynchus mykiss (anadromous rainbow trout) in the Central Valley of California were listed as threatened under the Endangered Species Act in 1998. Unfortunately, little is known about the distribution of steelhead in the tributaries of the Sacramento‐San Joaquin River system in the Central Valley or the relationship between sympatric anadromous and nonanadromous life history types. We used analysis of otolith strontium: Calcium (Sr:Ca) ratios to determine maternal origin (anadromous versus nonanadromous) and migratory history (anadromous versus nonanadromous) of rainbow trout collected in Central Valley rivers between 2001 and 2007. Of the 964 otoliths examined, 224 were determined to be from the progeny of steelhead females and 740 from the progeny of nonanadromous rainbow trout females. Progeny of steelhead maternal origin were present at all of the sites sampled, but the proportion varied among sites (0.04‐0.74). Based on transects of otolith Sr:Ca ratios, only five fish were confirmed to be adult steelhead. This is a conservative estimate of the distribution of adult steelhead since, due to conservation concerns, our sampling only collected a limited number of adults. The remaining 214 fish older than age 4 were not anadromous, and 16 of them were determined to be the progeny of steelhead females. Overall, these results refine our understanding of the distribution of steelhead in Central Valley rivers and confirm reports of steelhead occurrence in those rivers.
Using Trace Elements in Pectoral Fin Rays to Assess Life History Movements in Sturgeon: Estimating Age at Initial Seawater Entry in Klamath River Green Sturgeon
Authors: Allen Peter J. , Hobbs James A. , Cech Joseph J. , Van Eenennaam Joel P. , Doroshov Serge I. 
Published: February 2009

AbstractTo investigate the timing of the initial entry of green sturgeonAcipenser medirostrisinto seawater, we examined the ratios of strontium and barium to calcium in pectoral fin rays via laser ablation‐inductively coupled plasma‐mass spectrometry. In a reference group of six hatchery fish that was reared 1‐2 years in freshwater and 1‐3 years in seawater, we found a significant increase in the Sr:Ca ratio, a decrease in the Ba:Ca ratio, and an increase in the Sr:Ba ratio in calcified growth zones during the transition from freshwater to seawater. In 10 wild adults captured in the Klamath River, California, combined evaluation of the Sr:Ca and Ba:Ca ratios provided a clearer understanding of fish movements than the Sr:Ba ratio, probably because wild fish have a more complex life history. The Ba:Ca ratio dropped significantly between growth zones 1 and 2 (ages 0.5‐1.5), indicating a transition into saline waters, such as the Klamath River estuary. The Sr:Ca ratio increased slightly in the same location but attained the values found in reference fish held in seawater between growth zones 3 and 4 (ages 2.5‐3.5). The Sr:Ca, Ba:Ca, and Sr:Ba ratios in growth zones 4‐6 (ages 4.5‐6.5) of wild fish were similar to those found in reference fish held in seawater and corroborated the results of previous physiological studies as well as the limited field data. These results demonstrate the usefulness of trace element analyses of green sturgeon pectoral fin rays and confirm an early age of entry into seawater for this species.
Effects of American Water Willow Establishment on Density, Growth, Diet, and Condition of Age‐0 Largemouth Bass in Kansas Reservoirs
Authors: Strakosh Timothy R. , Gido Keith B. , Guy Christopher S. 
Published: February 2009

AbstractMany Kansas reservoirs are currently experiencing decreased sport fish production as a result of the typical aging processes that occur in impounded systems. American water willow Justicia americana was planted in three Kansas reservoirs (>1,800 ha) for littoral zone habitat enhancement to mitigate sport fish losses and increase the recruitment of age‐0 largemouth bass Micropterus salmoides. We investigated whether the density, growth, condition, and diet of age‐0 largemouth bass in coves with water willow differed from coves without water willow in these reservoirs. Samples of largemouth bass were collected from 2001 to 2004 in June, July, and August. We found a consistent pattern among reservoirs and sample years; coves with water willow had significantly greater densities of age‐0 largemouth bass than control coves, but no significant differences were found in growth, condition, or diet. Water willow beds appeared to buffer wave action, trapping fine sediments and floating debris, which significantly increased the overall habitat complexity. The additional organic material may have augmented littoral productivity, supporting the higher densities without physiologically hindering the age‐0 largemouth bass. Overall, our study suggests that water willow establishment is an effective means of enhancing littoral nursery habitat for age‐0 largemouth bass.
An Iterative Ensemble Kalman Filter for Multiphase Fluid Flow Data Assimilation
Authors: Gu Yaqing , Oliver Dean S. 
Published: February 2009

Summary
The dynamical equations for multiphase flow in porous media are highly non-linear and the number of variables required to characterize the medium is usually large, often two or more variables per simulator gridblock. Neither the extended Kalman filter nor the ensemble Kalman filter is suitable for assimilating data or for characterizing uncertainty for this type of problem. Although the ensemble Kalman filter handles the nonlinear dynamics correctly during the forecast step, it sometimes fails badly in the analysis (or updating) of saturations.
This paper focuses on the use of an iterative ensemble Kalman filter for data assimilation in nonlinear problems, especially of the type related to multiphase flow in porous media. Two issues are key: (1) iteration to enforce constraints and (2) ensuring that the resulting ensemble is representative of the conditional pdf (i.e. that the uncertainty quantification is correct). The new algorithm is compared to the ensemble Kalman filter on several highly nonlinear example problems, and shown to be superior in the prediction of uncertainty.