bluuebunny/crossref_metadata_2025_split huggingface dataset:
Measurements of Elastic Properties of Geomaterials in Laboratory Compression Tests
Authors: Tatsuoka F , Sato T , Park C-S , Kim Y-S , Mukabi JN , Kohata Y 
Published: February 2009

AbstractTwo types of axial loading devices having high and low capacities of axial load, respectively, for use in displacement-controlled compression tests on geomaterials (i.e., natural soils and rocks, and treated soils) in the laboratory are described. They were designed so that the loading direction can be reversed without any noticeable time lag under a highly constant axial strain rate while using a gear system. Results of representative triaxial and plane strain compression tests on a sand, a sedimentary soft rock, and a clay are presented. These results were obtained from very slow monotonic (or one-way) loading tests with several unload/reload cycles measuring axial strains locally along the lateral surfaces of a specimen continuously for a strain range from the order of 0.0001% (10−6) to that at failure. It is demonstrated that initial stiffness at strains less than about 0.001% (10−5) during primary loading is the same as stiffness during small unload/reload cycles applied immediately after the start of loading. Initial deformation properties are rather linear and elastic.
Impact-Echo Response of Hollow Cylindrical Concrete Structures Surrounded by Soil and Rock: Part II—Experimental Studies
Authors: Lin J-M , Sansalone M 
Published: February 2009

AbstractThe studies summarized in this paper demonstrate that the impact-echo method can be used for integrity testing of mine shaft and tunnel liners in contact with rock. Results obtained from experimental studies on mine shaft liners are presented. These results show that the measured impact-echo response depends upon the acoustic properties of the surrounding material as well as the acoustic properties and condition of the concrete structure. It is shown that cracks and voids in the concrete structure can be detected independent of the surrounding material. If the concrete structure is solid, the thickness of the concrete can be determined, except when the acoustic properties of the rock and concrete are similar and the concrete is bonded to the rock. The presence of delaminations or voids (either air- or water-filled) at the concrete/rock interface can be identified when the acoustic properties of the rock are similar or larger than those of the concrete.
Effect of Simulated Roots on the Permeability of Silty Soil
Authors: Gabr MA , Akram M , Taylor HM 
Published: February 2009

Abstract
A preliminary laboratory testing program was conducted to investigate the potential effect of vegetation on the hydraulic conductivity of soils used to construct levee structures. The testing program was conducted using a silty sand soil with a simulated root system. Testing apparatus included rigid-wall-double-ring permeameters and flexible-wall permeameters. The simulated roots were made using Balsa wood having a square cross section of 1.65 by 1.65 mm and approximately 12 to 25 mm in length. The measured hydraulic conductivity for specimens without simulated roots decreased as a function of the moisture content from approximately 1 × 10-3 cm/s to 5 × 10-4 cm/s. Values obtained using the flexible-wall device were less than those measured using the rigid-wall device by a factor of approximately 2. The addition of 1% simulated roots decreased the measured hydraulic conductivity, k. The reduction in k increased from less than 10% at a molding water content of 10% to approximately 50% at a water content of 25%. Similar behavior was observed in the case of specimens with 2% simulated roots. For γdry of 10 kN/m3, the estimated k values were 1 × 10-5 cm/s for the case of 2% roots versus 3 × 10-4 cm/s for the case of 1% roots. The k values decreased as the unit weight of the specimens was increased for both cases. In addition, the difference between k values obtained for specimens containing 1% and specimens containing 2% simulated roots increased as the dry unit weight of the specimens was increased.
Split-Hopkinson Pressure Bar Testing of Unsaturated Sand
Authors: Charlie WA , Ross CA , Pierce SJ 
Published: February 2009

Abstract
High amplitude, split-Hopkinson pressure bar (SHPB) laboratory tests were conducted on compacted specimens of 50/80 silica sand to evaluate the influence of saturation on compressional-stress wave velocity, stress transmission, and attenuation. Stress wave velocity and transmitted stress increase as the saturation increases from 0 to 30 to 40% for constant input stress and constant dry density. At saturation levels between 40 to 95%, both the wave speed and the transmitted stress decrease with increasing saturation. Quasistatic confined modulus show similar trends. These trends may be explained by capillary pressure.
Reinforcing Soil with Aligned and Randomly Oriented Metallic Fibers
Authors: Fatani MN , Bauer GE , Al-Joulani N 
Published: February 2009

Abstract
Laboratory direct shear box tests were used to evaluate the strength behavior of a reinforced uniform silty sand. The reinforcement elements consisted of flexible, semirigid, and rigid metallic fibers. The orientations of the fibers to the shear plane were varied and had a marked effect on the shear resistance. Increases in peak and residual strengths of 100 and 300%, respectively, were observed over unreinforced sand. Specimens reinforced with randomly oriented flexible fibers also exhibited a similar improvement of strength parameters.
Clay Lumps under Simulated Hydraulic Transport Conditions
Authors: Leshchinsky D , Richter SD , Fowler J 
Published: February 2009

Abstract
Laboratory experiments with compacted kaolinite-bentonite mixtures indicate that degradation of hydraulically transported clay lumps in a dredge pipeline can be predicted and controlled to some extent. The size reduction of these lumps depends not only on the length of the pipeline but also on the density of the clay being dredged, the plasticity index (PI) of the clay, and the velocity of the dragging slurry in the pipe. A series of graphs shows percent reduction in clay lumps as a function of PI and velocity at three levels of relative compacted density.
If the relationships obtained in this study are shown to be valid in the field, this information will be useful in selecting dredging equipment, designing dredged material containment area, and estimating costs. Relatively undisturbed specimens of the in situ clay and simple laboratory tests would provide the necessary information.
The Measurement of Stiffness Anisotropy in Clays with Bender Element Tests in the Triaxial Apparatus
Authors: Jovičić V , Coop MP 
Published: February 2009

Abstract
The paper presents the results of a program of research investigating the effectiveness of bender elements when used in conjunction with the triaxial apparatus for measuring the anisotropy of small strain stiffness of fine-grained soils. Tests were carried out on both intact and reconstituted samples of London clay and on kaolin up to high stresses. The paper shows that the transverse isotropy of small-strain stiffness that commonly occurs in many soils because of a one-dimensional loading history can be fully investigated in the conventional triaxial apparatus and that London clay is an example of such a soil. The stress-induced component of anisotropy was found to be very small for axi-symmetric loading conditions common to both the appartus and the in situ state of these soils. In contrast, the inherent or structural anisotropy was much more significant and is shown to be a variable factor resulting from the plastic strain history and is not related to its natural structure. Consequently, inherent anisotropy is reversible, but the rate of change is very slow when a new regime of stresses is imposed. Inherent anisotropy of the very small strain stiffness also persists long after the plastic strains of the soil have become oriented toward the new stresses.
On Some Issues in Triaxial Extension Tests
Authors: Wu W , Kolymbas D 
Published: February 2009

Abstract
Results of triaxial extension tests on dry sand are presented. Special attention is paid to the factors influencing the results in triaxial extension tests. It is found that factors such as accuracy of the axial force measurement, axial force carried by the rubber membrane surrounding the specimen, gravity, and inhomogeneous deformation have a much larger influence on the results in triaxial extension tests than in triaxial compression tests. Accurate measurement of the axial force is achieved by placing the load cell inside the pressure chamber. The influence of the confining pressure on the axial force measurement is avoided through a proper construction. The force carried by the rubber membrane is corrected with reference to the result of a tension test on a strip of rubber membrane. The effect of gravity is accounted for by adding the axial stress due to gravity to the applied axial stress. The inhomogeneous deformation is traced by three lateral strain collars placed along the specimen height. Results of triaxial extension tests cannot be appreciated if these influential factors are not taken into account.
The failure mode of the specimen is found to be influenced largely by the initial density. Inhomogeneous deformation in the form of necking develops in the upper part of dense specimens and in the middle of loose specimens. For dense specimens, the necked region becomes wider with advanced deformation and develops into one single or two intersecting shear bands. For loose specimens, however, no shear bands can be observed.
The Toluene and Wax-Freezing Method of Determining Volumetric Free Swell
Authors: Pellissier JP 
Published: February 2009

Abstract
Swelling clay and rock are a common problem worldwide, and for design purposes it is necessary to quantify the free-swell behaviour of such material. A technique to measure the volumetric free swell of a swelling clay (called the toluene and wax-freezing volumetric free-swell method) is suggested here and consists of two approaches to measuring the volume of a specimen at different moisture contents. Both approaches have certain limitations, but fortunately they complement each other.
The author required a volumetric free-swell method which could be performed with practically zero external load on the sample during free swell and where the scatter in the recorded results would be low. An optional requirement was that one should be able to perform the test in a field laboratory with only a few samples and a minimum of equipment.
The results should be presented in such a way as to make interpretation and prediction easy.
Determination of Local Displacements on Soil Samples
Authors: Symes MJ , Burland JB 
Published: February 2009

Abstract
A description is given of two types of laboratory instrumentation suitable for monitoring deformations locally over a central portion of a soil sample. Using this instrumentation the problems caused by apparatus compliance, by bedding of the end caps, and by imposition of zero lateral movement at the ends of the sample (such as in conventional cylindrical tests) are avoided. In this paper the instruments are used to determine the three principal strains in a hollow cylindrical sample, which is subject to different axial, horizontal shear, radial, and circumferential stresses.
A Fast Triaxial Shear Device
Authors: Carroll WF 
Published: February 2009

Abstract
The fast triaxial shear device (FTRXD) loads a 1.9-cm (0.75-in.) diameter by 3.8-cm (1.5-in.) long soil specimen, deforming it axially at a very rapid rate. The specimen is deformed by a piston-cylinder assembly driven by compressed nitrogen. Load and displacement at the top of the specimen and load at the bottom are measured; the specimen is subjected to a confining pressure up to 6.9 MPa (1000 psi). The shortest times to failure to date have been 0.5 ms. Soil from the CARES-Dry Luke Gunnery Range in Arizona was used in the evaluation. It is a clayey sand (SC) in the Unified Soils Classification System. The moving upper load cell is sensitive to specimen inertia and FTRXD dynamics; the stationary lower load cell is much less so. Both load measurements and the displacement of the specimen top are needed for wave analyses of the specimen and assessment of FTRXD dynamics.
Design and Performance of Soil-Pile-Slip Test Apparatus for Tension Piles
Authors: Reddy ES , Chapman DN , O'Reilly M 
Published: February 2009

Abstract
The T-Z method is the common method available to estimate load-displacement behavior of tension piles. Obtaining accurate T-Z curves from laboratory tests has a vital role in better estimation of pile behavior. The available apparatus used to obtain laboratory T-Z curves (Coyle and Sulaiman 1967) suffers from a set of limitations.
A soil-pile-slip test apparatus has been designed at the University of Nottingham (UK) to obtain better T-Z curves for tension piles. This paper presents the design details and the testing procedure of the soil-pile-slip test apparatus. A set of T-Z curves obtained using this apparatus is analyzed, which provides insight into the mechanism of soil-pile-slip dilation near the pile surface.
Some Observations on the Laboratory Measurement of Soil-Geotextile Bond
Authors: Ingold TS 
Published: February 2009

Abstract
To determine soil-geotextile bond the engineer has, at present, two main test techniques, namely, the shear box and the pull-out test. A comparison of results for these two techniques has been made for three geotextiles, two fabrics and one grid, that have been used in the United Kingdom as soil reinforcement. Four test techniques have been employed, three based on the shear box and the fourth, a pull-out test. The 300- by 300-mm shear box has been used in the fixed shear mode where the geotextile is bonded to a rigid base plate and the free shear mode where the geotextile is clamped to one end of the lower half of the shear box with soil above and below. Use of the 60- by 60-mm shear box has been limited to the fixed shear mode. Analysis of the test results for any one geotextile show that the shear box results are in good agreement with one another. In most cases the angle of bond stress is independent of normal stress level. A quite different result was obtained for the pull-out test; the angle of bond stress decreased with increasing normal stress level. The results are discussed in detail and it is concluded that although the shear box test technique might prove useful as an index test the pull-out test, even with only qualitative interpretation, is the most suitable for systems testing by virtue of its ability to detect faults in the structure of the geotextile.
Soil Remolding and Sensitivity Measurements
Authors: Yong RN , Tang KY 
Published: February 2009

AbstractThis study examines the problem of measurement of soil sensitivity and the significance of soil remolding effects on the “remolded” strength of soil. A simple shear device has been adapted to provide a means for both soil remolding and continuous measurement of shear stress and strain using cyclic stress reversals. Computations can be made to relate soil remolding and input energy for correlation with measured remolded soil strength using the simple shear device.
A Servo System for Hollow Cylinder Testing of Soils
Authors: Shibuya S 
Published: February 2009

Abstract
A fully digitized servo-control system, coupled with the automatic data acquisition facility, has been developed for a hollow cylinder apparatus (HCA). The closed-loop servo-control is based on a computer through which four individual stresses acting on the hollow cylindrical specimen can be independently changed using pneumatic regulators driven by stepper motors. The range of tests that can be performed in the HCA is considerably expanded to include boundary displacement controlled tests, as well as genuine stress controlled tests under generalized stress conditions involving principal stress rotation. This paper describes the detailed features both of the hardware and software of the servo-system. The experimental capabilities of the servo-system, together with its limitations, are discussed using test results that deal with particular aspects of the stress and strain paths associated with in-situ and laboratory loading.
Prediction of Field Compressibility from Laboratory Consolidation Tests of Peats and Organic Soils
Authors: Stinnette P 
Published: February 2009

Abstract
Gibson and Lo (1961) compressibility parameters a and b for an organic soil can be determined from the organic content and the current pressure using the model presented by Gunaratne et al. (1998). These parameters, however, were developed based on results of laboratory one-dimensional consolidation tests and are valid for the K0 state. Researchers such as Edil et al. (1984) have found that the experimentally determined values of b in particular are larger for field situations. Therefore, the compressibility parameters have to be modified to predict field settlement under surcharges. This paper describes an extended model that addresses this issue and demonstrates how the laboratory-based b value can be corrected for field loading conditions. Finally, results of a full-scale, instrumented field settlement study of organic soil are shown to correlate well with the predictions of the extended model.
Effects of Non-Plastic Fines on Minimum and Maximum Void Ratios of Sand
Authors: Lade PV , Liggio CD , Yamamuro JA 
Published: February 2009

Abstract
The behavior of sand is affected by the content of nonplastic fine particles. How and to what degree the fines content affects the minimum and maximum void ratios has been studied in detail. A review is presented of previous theoretical and experimental studies of minimum and maximum void ratios of single spherical grains, packings of spheres of several discrete sizes, as well as optimum grain-size ratios to produce maximum densities. A systematic experimental study is performed of the variation of minimum and maximum void ratios with contents of fines for sands with smoothly varying particle size curves and a large variety of size distributions. It is shown that the fines content plays an important role in determining the sand structure and the consequent minimum and maximum void ratios. It is indicated how the fines content and sand structure affects the compressibility and the static liquefaction potential of the sand.
Epidemiologic Features of Kawasaki Disease in Taiwan, 2003–2006
Authors: Huang Wen-Chan , Huang Li-Min , Chang I-Shou , Chang Luan-Yin , Chiang Bor-Luen , Chen Pei-Jer , Wu Mei-Hwan , Lue Hung-Chi , Lee Chun-Yun ,   and the Kawasaki Disease Research Group
Published: February 2009

OBJECTIVE. Kawasaki disease is the leading cause of acquired heart disease in children worldwide. This study characterizes the epidemiology of Kawasaki disease in Taiwan between 2003 and 2006.
METHODS. Using Taiwan's 2003–2006 national health insurance claims, we investigated the epidemiologic features of Kawasaki disease (ICD-9-CM code 446.1) and coronary artery aneurysm formation (International Classification of Diseases, Ninth Revision, Clinical Modification code 414.11) and compared the incidences of these diseases with those occurring between 1996 and 2002 in Taiwan and those reported by other countries.
RESULTS. During our 4-year study period, 3877 children and adolescents &lt;20 years of age were hospitalized for Kawasaki disease. Ninety percent of these children were &lt;5 years of age, and the male/female ratio was 1.62:1. The annual incidence of Kawasaki disease was 153 in 100000 children &lt;1 year of age, 111 in children 1 year of age, 58 in children 2 years of age, 30 in children 3 years of age, 19 in children 4 years of age, and 5.2 in children 5 to 9 years of age. The overall incidence was 69 cases per 100000 for children &lt;5 years of age. Kawasaki disease recurred in 1.5% of all cases. Kawasaki disease occurred most frequently in the summer and least frequently in the winter. Coronary artery aneurysm occurred in 7.2% (279 of 3877) of all Kawasaki disease cases.
CONCLUSIONS. The overall incidence of Kawasaki disease was 69 in 100000 children &lt;5 years of age between 2003 and 2006 in Taiwan, comparable with the incidence of 66 in 100000 children between 1996 and 2002. Taiwan has the third highest incidence of Kawasaki disease in the world, after Japan and Korea. In Taiwan, it occurs more frequently during the summer.
Preparation of Yb-Doped Sc2O3 Transparent Ceramics for Laser Applications
Authors: Longuet Laurence , Bravo Anne-Cecile , Autissier Denis , Vissie Pascal , Longuet Jean-Louis , Lambert Sebastien 
Published: February 2009

AbstractPolycrystalline transparent Yb:Sc2O3 ceramics were obtained in the best conditions by a solid-state reaction route using high purity Sc2O3 and Yb2O3 powders with TEOS as a sintering aid. The as-prepared powders containing various ytterbium content were characterized by BET measurements, XRD and FEG-SEM. The sintering behaviour of the powders was investigated by dilatometry. The sintered materials microstructures were observed by FEG-SEM. EPMA allowed to characterize the repartition of the dopant Yb3+ in the Sc2O3 matrix.
Phase Equilibria and Crystal Growth for LiREF4 Scheelite Laser Crystals
Authors: Klimm Detlef , Dos Santos Ivanildo A. , Ranieri Izilda M. , Baldochi Sonia L. 
Published: February 2009

AbstractThe scheelite type laser crystals LiREF4 melt congruently only for RE being one of the elements Er, Tm, Yb, Lu, or possibly Y, respectively. For RE = Eu, Gd, Tb, Dy, or Ho the corresponding scheelites undergo a peritectic melting under the formation of the corresponding rare earth fluoride. The melting behavior of LiREF4 mixed crystals with two or more RE is not yet known well. If RE is a mixture of Gd and Lu, Gd rich solid solutions melt peritectically under formation of (Gd,Lu)F3 and Lu rich solid solutions melt directly without formation of other solid phases.
Ferromagnetism and Luminescence of Diluted Magnetic Semiconductors GaGdN and AlGdN
Authors: Emura Shuichi , Takahashi Masahiro , Tambo Hiroyuki , Suzuki Akira , Nakamura Tetsuya , Zhou Yi-Kai , Hasagawa Shigehiko , Asahi Hajime 
Published: February 2009

AbstractThe magnetic characteristics of the dilute magnetic system GaGdN are investigated by mainly soft-X-ray magnetic circular dichroism (MCD) in energy range of 1160 – 1240 eV. The strong MCD signals up to 30 % at 15K are observed. The temperature dependence of its intensity is not on simple Curie-Weiss curve and depicts three-step curve. A step around 40 – 100K suggests a new magnetic phase. The luminescence spectrum of GaGdN at low temperature is divided into three parts consisting of two broad bands around 432 nm and 503 nm and a sharp peak at 652 nm. This sharp line is assigned to the intra-transition of f – f orbital owing to the weak temperature dependence of the intensity and peak position. AlGdN grown by molecular beam epitaxy produces luminescence at 318.5 nm. X-ray absorption fine structure is examined to survey the occupancy of the Gd ion in the grown specimens.
Anomalous Hall Effect in Gd-implanted Wurtzite AlxGa1-xN High Electron Mobility Transistor Structures
Authors: Lo Fang-Yuh , Melnikov Alexander , Reuter Dirk , Cordier Yvon , Wieck Andreas D. 
Published: February 2009

AbstractAlxGa1-xN/GaN high electron mobility transistor (HEMT) structures grown by ammonia-source molecular beam epitaxy (MBE) are focused-ion-beam implanted with 300 keV Gd-ions at room temperature. The two-dimensional electron gas (2DEG) of these HEMT structures is located 27 nm underneath the sample surface. At 4.2 K, current-voltage characteristics across implanted rectangles show that the structures remain conducting up to a Gd-dose of 1×1012cm-2. Anomalous Hall effect (AHE) is observed at T = 4.2 K for structures implanted with Gd, whose dose is 3×1011cm-2. Measurements of AHE in the wide temperature range from 2.4 K to 300 K show that the magnetic ordering temperature of these structures is around 100 K. Therefore, these Gd-implanted HEMT structures containing the still conducting 2DEG, which is now embedded in a ferromagnetic semiconductor, open the possibility to polarize the electron spins.