bluuebunny/crossref_metadata_2025 huggingface dataset:
Model for the prediction of shear strength with respect to soil suction
Authors: Vanapalli S K , Fredlund D G , Pufahl D E , Clifton A W
Published: April 2008

Experimental studies on unsaturated soils are generally costly, time-consuming, and difficult to conduct. Shear strength data from the research literature suggests that there is a nonlinear increase in strength as the soil desaturates as a result of an increase in matric suction. Since the shear strength of an unsaturated soil is strongly related to the amount of water in the voids of the soil, and therefore to matric suction, it is postulated that the shear strength of an unsaturated soil should also bear a relationship to the soil-water characteristic curve. This paper describes the relationship between the soil-water characteristic curve and the shear strength of an unsaturated soil with respect to matric suction. Am empirical, analytical model is developed to predict the shear strength in terms of soil suction. The formulation makes use of the soil-water characteristic curve and the saturated shear strength parameters. The results of the model developed for predicting the shear strength are compared with experimental results for a glacial till. The shear strength of statically compacted glacial till specimens was measured using a modified direct shear apparatus. Specimens were prepared at three different water contents and densities (i.e., corresponding to dry of optimum, and wet of optimum conditions). Various net normal stresses and matric suctions were applied to the specimens. There is a good correlation between the predicted and measured values of shear strength for the unsaturated soil.

Key words: soil-water characteristic curve, shear strength, unsaturated soil, soil suction, matric suction.
Pipesoil interaction analysis of jointed water mains
Authors: Rajani B , Zhan C , Kuraoka S
Published: April 2008

Water mains are important lifelines of modern urban infrastructure. However, in most developed countries, the average life of these cast or ductile iron pipes approaches 5075 years. In recent years, the disruption of water sevices as a consequence of water main breaks is on the rise in most Cadadian cities. This paper describes the developement of a simplified Winkler model to stimulate the responses of a jointed water main subjected to differential temperature change and water pressure. The simplified Winkler model accounts for axial and radial restraints offered by the surronding soil. In spite of its simplicity, the Winkler model is able to predict the overall response of strains and stresses, which confirms satisfactorily some of heuristic and documented observations on water main breaks.

Key words: water main breaks, pipesoil interaction, temperature influence, Winkler model.
Effects of stress and temperature on secondary compression of peat
Authors: Fox Patrick J , Edil Tuncer B
Published: April 2008

Results from field and laboratory tests illustrate the influence of vertical effective stress and temperature on the secondary compression of peat from Middleton, Wisconsin, U.S.A. A large fraction of the total settlement of the peat is due to secondary compression. The coefficient of secondary compression, Calpha, generally increases with time, and settlement predictions using a constant Calpha may underestimate field settlement. Laboratory step-stress and step-temperature tests indicate that the rate of void ratio change during secondary compression varies exponentially with both temperature and vertical effective stress. A stress coefficient of creep, Ctheta, and a temperature coefficient of creep, CT, are defined to characterize these relationships. For Middleton peat, the logarithm of Ctheta decreases linearly with void ratio and CT is constant. The results suggest that laboratory stress and temperature conditions should match those in situ for accurate determination of secondary compression parameters. Cooling also has an important effect on the secondary compression of peat. For large decreases in temperature, an overconsolidated condition is created for which additional secondary compression is greatly reduced. Settlement data from two test embankments on peat illustrate the effect of staged construction and subsurface heating on secondary compression in the field. The temperature changes achieved in situ were not large enough to cause a strong thermal precompression effect.

Key words: peat, organic soil, secondary compression, consolidation, settlement.
Contaminant transport through a soil liner underlain by an unsaturated stone collection layer
Authors: Badv K , Rowe R Kerry
Published: April 2008

Chloride and sodium migration in an unsaturated stone collection system underlying a compacted soil liner was examined for three different flow rates ranging between 2.5 and 0.017 m/a. Relatively high and uniform concentrations were observed in the unsaturated stone layer. The groundwater velocity played a significant role in contaminant transport through unsaturated stone even at a flow of 0.017 m/a. Experimental observations were accurately predicted using one-dimensional advectivediffusivedispersive theory. Transport parameters were reduced by modelling the test data.

Key words: soil liner, unsaturated flow, diffusion, landfill, collection system.
Rock instability and risk analyses in open stope mine design
Authors: Diederichs Mark S , Kaiser Peter K
Published: April 2008

Modern underground mining methods often call for the excavation of large, often unsupported voids called stopes. In many cases, these are nonentry stopes, with the removal of broken rock (mucking) performed by remote control. With the risk to human safety thus reduced, stability concerns within the stopes are primarily driven by the economics of unplanned overbreak and waste rock dilution of the mined ore. In this context, it is appropriate to speak of acceptable risks of instability and to optimize design by balancing risk costes with productivity potential. Larger individual stopes generally increase productivity while reducing stability. The modified stability graph is a popular empirical mine design tool that has been calibrated to provide discrete recommendations for maximum stope dimensions based on a rock quality index. It seems appropriate to extend the method to account for variability in the calibration data and also for variability in each new set of input parameters. A risk template and associated probabilistic techniques are proposed to supplement the discrete design limits currently established.

Key words: risk, mining, stability, design, emperical.
The relationship of the unsaturated soil shear strength to the soil-water characteristic curve
Authors: Fredlund D G , Xing Anqing , Fredlund M D , Barbour S L
Published: April 2008

The measurement of soil parameters, such as the permeability and shear strength functions, used to describe unsaturate soil behaviour can be expensive, difficult, and often impractical to obtain. This paper proposes a model for predicting the shear strength (versus matric suction) function of unsaturated soils. The prediction model uses the soil-water characteristic curve and the shear strength parameters of the saturated soil (i.e., effective cohesion and effective angle of internal friction). Once a reasonable estimate of the soil-water characteristic curve is obtained, satisfactory predictions of the shear strength function can be made for the unsaturated soil. Closed-form solutions for the shear strength function of unsaturated soils are obtained for cases where a simple soil-water characteristic equation is used in the prediction model.

Key words: soil suction, soil-water characteristic curve, shear strength function, unsaturated soil.
Stress-dependent flow through fractured clay till: a laboratory study
Authors: Sims John E , Elsworth Derek , Cherry John A
Published: April 2008

Stress-dependent hydraulic conductivities of weathered fractured clay till were measured in a flexible-wall permeameter. Measured conductivities were in the range 107 to 108 cm/s, of the same order as the clay matrix (108 cm/s), and representing equivalent hydraulic apertures in the range 05 μm. In general, the isolated fractures exhibited strongly nonlinear closure characteristics and hysteric behaviour under stress reversal. Some fracture samples exhibited only weak stress dependency, representing observable features of only nominal conductivity. Results of the investigations suggest fractures are closed to residuel aperture for an overburden load of the order of 12 m, this defining an effective closure depth and the degree of maximum useful compactive effort that might be applied to "seal" fractures and reduce fluid migration.

Key words: fracture permeability, till, stress permeability, landfills.
Hydraulic conductivity of homogenized tailings from hard rock mines
Authors: Aubertin Michel , Bussiere Bruno , Chapuis Robert P
Published: April 2008

Tailings produced by milling for one extraction from hard rock mines, which range in size from clay to fine sand, have relatively low hydraulic conductivity, k. The value of k must be known with a certain degree of certainty to analyze consolidation and seepage conditions in and around tailings ponds. In this paper, the authors present the results of a laboratory investigation on hydraulic conductivity of homogenized tailings from hard rock mines. After describing some of the basic properties of four different materials, including mineralogy, grain size, Atterberg limits, compaction characteristics, and consolidation curves, permeability test results are given. The hydraulic conductivity value usually varies between 104 and 105 cm/s. The effect of various factors on this value, including void ratio and grain size, is then discussed in relation to predictive models. It is shown that a modified version of the Kozeny-Carman equation, in which a tortuosity factor and a grain-size distribution function are included explicitly, can represent the data very well. The equation is also checked against results taken from the literature on similar types of materials.

Key words: tailings, hydraulic conductivity, laboratory tests, void ratio, grain size, tortuosity.
Statistical relationships between piezocone measurements and stress history of clays
Authors: Chen B SY , Mayne P W
Published: April 2008

A database containing piezocone soundings from 205 clay sites around the world has been compiled for the calibration of an analytical cone penetration model and the development of statistical correlations. Yield stresses from laboratory oedometer tests were used as reference values for determining the stress history of natural clay deposits. Both simple and multiple regression analyses were performed on these data to evaluate correlative trends. Several simplified empirical relationships were identified for use in practice with the most reliable in relating preconsolidation stress to net cone tip resistance.

Key words: cone tip resistance, overconsolidation ratio (OCR), preconsolidation pressure, piezocone, statistical relationships, stress history.
A capillary flow meter for measuring the hydraulic conductivity of clay under low gradients
Authors: Ranjan R Sri , Karthigesu T
Published: April 2008

The measurement of water flow through clay at low hydraulic gradients (<1) is a very difficult task requiring several months to accomplish in a laboratory. A capillary flow meter, capable of measuring extremely low flow rates through clay samples under low imposed hydraulic gradients, has been designed and tested. Flux as low as 1012 m·s1 was successfully measured using this flow meter. To minimize the contaminatiion effects, perchloroethylene, which has self-cleaning ability, mixed with Sudan IV was used as the bubble liquid in the capillary flow meter. Glass and Teflon® valves were fused to the inflow and outflow capillary tubes to permit these components to be flushed with cleaning agents and distilled water. The movement of the menisci through the capillary tube was used as a measure of the volume flow rate through the sample. A sensitive differential pressure transducer was connected between the inflow and outflow end of the clay sample to measure the imposed hydraulic head difference. This flow meter has been independently calibrated against a conventional constant head permeameter. Once the clay samples have stabilized in a permeameter, oedometer, or a triaxial cell, multiple flow measurements under low hydraulic gradients can be done in less than an hour.

Key words: nonlinear flow, saturated hydraulic conductivity, non-Darcy flow, ultra-low flow meter.
Shear moduli and damping in frozen and unfrozen clay by resonant column tests
Authors: Al-Hunaidi M O , Chen P A , Rainer J H , Tremblay M
Published: April 2008

The resonant-column test method was used in this study to determine the dynamic shear moduli and damping ratios of frozen and unfrozen soil samples. Naturally frozen soil specimens were obtained in-situ during the winter. A series of tests were carried out on the frozen soil specimens in a cold room at 9°C. The same specimens, after allowing them to thaw, were then tested at room temperature. Test results show that at low-amplitude shear stains the damping ratio of frozen soil specimens is roughly twice that of unfrozen samples. In addition, the dynamic shear modulus for soil specimens while frozen is significantly greater (30 or 50 times) than that of unfrozen specimens. These results provide a basis for explaining an observation that bus-induced vibrations in buildings while the top soil is frozen in winter are about one-half those induced while the soil is not frozen.

Key words: resonant-column test, shear modulus, damping ratio, frozen soil, ground vibration.
The pine-wood nematode, Bursaphelenchusxylophilus, in Minnesota and Wisconsin: insect associates and transmission studies
Authors: Wingfield M. J. , Blanchette R. A.
Published: April 2008

The pine-wood nematode, Bursaphelenchusxylophilus (Steiner and Buhrer), was most commonly extracted from Cerambycidae emerging from nematode-infested pines in Minnesota and Wisconsin during 1981 and 1982. The greatest number of nematodes were extracted from Monochamusscutellatus (Say) and Monochamuscarolinensis (Olivier). Low numbers of B. xylophilus were found in some buprestids but no nematodes were found in the curulionid and scolytid beetles examined. Two species of Cerambycidae, Monochamusmannorator (Kiby.) and M. scutellatus were associated with B. xylophilus from balsam fir in Minnesota. Bursaphelenchusxylophilus from insects associated with balsam fir were morphologically different from insects associated with pine. Dauer larvae of B. xylophilus were concentrated in the thoracic segments of M. scutellatus and Monochamusmutator (Lec.) examined. Bursaphelenchusxylophilus was transmitted to twigs during maturation feeding and to logs during oviposition by M. carolinensis, M. mutator, and M. scutellatus.
Influence of phosphorus on growth and biomass distribution of Alaskan taiga tree seedlings
Authors: Chapin III F. Stuart , Tryon Peter R. , Cleve Keith Van
Published: April 2008

Seedlings of six Alaskan taiga tree species and one tall shrub were grown in sand at three phosphate levels. There was a positive correlation between the growth rate of a species at the high-phosphate level in sand culture and its productivity in the natural environment. Poplar (Populusbalsamifera L.), which had highest growth rate under high phosphate, was most sensitive to reduction in phosphate supply, followed by birch (Betulapapyrifera (Reg.) Fern, and Raup) and aspen (Populustremuloides Michx.), whereas growth of conifers (larch (Larixlaricina (Du Roi) K. Koch), white spruce (Piceaglauca (Moench) Voss), and black spruce (P. mariana (Mill.) B.S.P.)) from late successional sites was slow and unaffected by phosphate supply. Similarly, when birch and white spruce seedlings were transplanted into natural forest stands, the maximum growth rate of birch was greater than that of white spruce, but birch growth was curtailed more by unfavorable conditions than was that of white spruce. We conclude that a slow growth rate reduces nutrient requirement and therefore minimizes nutrient stress on infertile sites, whereas a rapid growth enables nutrient-demanding species to dominate fertile sites.
Association of Verticicladiellaprocera and Leptographiumterrebrantis with insects in the Lake States
Authors: Wingfield Michael J.
Published: April 2008

Verticicladiellaprocera Kendrick was isolated from damage associated with Dendroctonusvalens Lec, Hylobiusradicis Buch., Hylobiusrhizophagus M.B.W., Hylobiuspales (Herbst), and Pachylobiuspicivorus (Germ.) on pines in Minnesota, Wisconsin, and Michigan. The fungus was also isolated from surface-sterilized adult D. valens, H. radicis, H. pales, and P. picivorus. Leptographiumterrebrantis Barras and Perry was isolated from the galleries of D. valens on trees stressed by fire, flooding, windthrow, and tissue attacked by H. radicis or H. rhizophagus. Verticicladiellaprocera was not pathogenic on white pine seedlings whereas L. terrebrantis killed 70% of seedlings inoculated. Verticicladiellaprocera appears to be weakly pathogenic and is associated with primary (H. radicis and H. rhizophagus) and secondary (P. picivorus, D. valens, H. pales) forest insects in the north central United States. Leptographiumterrebrantis was more virulent than V. procera and was associated with a secondary bark beetle which commonly attacks stressed trees.
RANDOM ATTRACTORS FOR DAMPED STOCHASTIC WAVE EQUATIONS WITH MULTIPLICATIVE NOISE
Authors: FAN XIAOMING
Published: April 2008

In this paper, we investigate the existence of compact random attractors and their fractal dimension for the random dynamical systems determined by damped stochastic wave equations of Sine–Gordon type with linear multiplicative noise.
κ-DEFORMED STATISTICS AND CLASSICAL FOUR-MOMENTUM ADDITION LAW
Authors: DASZKIEWICZ MARCIN , LUKIERSKI JERZY , WORONOWICZ MARIUSZ
Published: April 2008

We consider κ-deformed relativistic symmetries described algebraically by modified Majid–Ruegg bi-cross-product basis and investigate the quantization of field oscillators for the κ-deformed free scalar fields on κ-Minkowski space. By modification of standard multiplication rule, we postulate the κ-deformed algebra of bosonic creation and annihilation operators. Our algebra permits one to define the n-particle states with classical addition law for the four-momentum in a way which is not in contradiction with the nonsymmetric quantum four-momentum co-product. We introduce κ-deformed Fock space generated by our κ-deformed oscillators which satisfy the standard algebraic relations with modified κ-multiplication rule. We show that such a κ-deformed bosonic Fock space is endowed with the conventional bosonic symmetry properties. Finally we discuss the role of κ-deformed algebra of oscillators in field-theoretic noncommutative framework.
SOFTWARE EFFORT ESTIMATION BY ANALOGY USING ATTRIBUTE SELECTION BASED ON ROUGH SET ANALYSIS
Authors: LI JINGZHOU , RUHE GUENTHER
Published: April 2008

Estimation by analogy (EBA) predicts effort for a new project by learning from the performance of former projects. This is done by aggregating effort information of similar projects from a given historical data set that contains projects, or objects in general, and attributes describing the objects. While this has been successful in general, existing research results have shown that a carefully selected subset, as well as weighting, of the attributes may improve the performance of the estimation methods.

In order to improve the estimation accuracy of our former proposed EBA method AQUA, which supports data sets that have non-quantitative and missing values, an attribute weighting method using rough set analysis is proposed in this paper. AQUA is thus extended to AQUA+by incorporating the proposed attribute weighting and selection method. Better prediction accuracy was obtained by AQUA+compared to AQUA for five data sets. The proposed method for attribute weighting and selection is effective in that (1) it supports data sets that have non-quantitative and missing values; (2) it supports attribute selection as well as weighting, which are not supported simultaneously by other attribute selection methods; and (3) it helps AQUA+to produce better performance.
DESIGN OF A CIL CONNECTOR TO SPIN
Authors: LI YONGJIAN , XUE RUI
Published: April 2008

The CAPSL Integrated Protocol Environment effort aims at providing an intuitive and expressive language for specifying cryptographic authentication and key distribution protocols and supporting interfaces to various analysis tools. The CAPSL Intermediate Language (CIL) has been designed with the emphasis on simplifying translators from CIL to other analysis tools. In this paper we describe the design of a CIL-to-Spin connector. We describe how CIL concepts are translated into Spin and propose a general method to model the behaviors of honest principals and the intruder. Based on the method, a prototype connector has been implemented in Gentle, which automatically translates CIL specifications to Promela codes and LTL formulae, thus greatly simplifying the modeling and analysis process.
COMPOSING MULTI-PERSPECTIVE SOFTWARE REQUIREMENTS SPECIFICATIONS
Authors: MARTÍNEZ ANA BELÉN BARRAGÁNS , ARIAS JOSÉ J. PAZOS , VILAS ANA FERNÁNDEZ , DUQUE JORGE GARCÍA , NORES MARTÍN LÓPEZ , REDONDO REBECA P. DÍAZ , FERNÁNDEZ YOLANDA BLANCO
Published: April 2008

One of the main needs when dealing with multi-perspective specifications is to be able to have at our disposal, at intermediate stages of the development process, a merged view which properly reflects the knowledge of each participant in the elicitation tasks (and over which we can reason, even in the presence of disagreement and incompleteness).

We show in this paper to what extent there can be many merged models, having all of them useful application. So there is not a unique operator which can be qualified as the best; on the contrary, there will be a suitable merging operator depending on the goal of the merging process. More concretely, we will propose a set of four composition operators: ∐max, ∐min, ∐majand ∐maj + inc. They will be evaluated making use of a list of desired algebraic properties proposed by researchers on merging and which should be held by an ideal merging operator. This analysis can help us to compare the different operators, revealing the key features of each, and identifying weaknesses that may require further research. The conclusion drawn after this analysis points out that these properties are not useful enough to adequately characterize a merging operator. Therefore, new properties will be provided in order to complete the previous list and help to define better the behavior of the different merging operators.
TEXT SUMMARIZATION USING LEXICAL COHESION: APPROACHES AND EVALUATIONS
Authors: CHALI YLLIAS
Published: April 2008

Popularity of the Internet has contributed towards the explosive growth of online information, and it is especially useful to have tools which can help users digest information content. Text summarization addresses this need by taking a source text, selecting the most important portions of it, and presenting coherent summary to the user in a manner sensitive to the user's or application's needs. The goal of this paper is to show how these objectives can be achieved through an efficient use of lexical cohesion. The current work addresses both generic and query-based summaries in the context of single documents and sets of documents as in current news. We present an approach for identifying the most important portions of the text which are topically best suited to represent the source texts according to the author's views or in response to the user's interests. This identification must also take into consideration the degree of connectiveness among the chosen text portions so as to minimize the danger of producing summaries which contain poorly linked sentences. We present a system that handles these objectives, discuss its performance, and evaluate it and compare it to other systems in the context of Document Understanding Conference (DUC) evaluations.
NATURE INSPIRED INTELLIGENCE IN MEDICINE: ANT COLONY OPTIMIZATION FOR PAP-SMEAR DIAGNOSIS
Authors: MARINAKIS YANNIS , DOUNIAS GEORGIOS
Published: April 2008

During the last years nature inspired intelligent techniques have become attractive for analyzing large data sets and solving complex optimization problems. In this paper, one of the most interesting of them, the Ant Colony Optimization (ACO), is used for the construction of a hybrid algorithmic scheme which effectively handles the Pap Smear Cell classification problem. This algorithmic approach is properly combined with a number of nearest neighbor based approaches for performing the requested classification task, through the solution of the so-called optimal feature subset selection problem. The proposed complete algorithmic scheme is tested in two sets of data. The first one consists of 917 images of pap smear cells and the second set consists of 500 images, classified carefully by expert cyto-technicians and doctors. Each cell is described by 20 numerical features, and the cells fall into seven (7) classes, four (4) representing normal cells and three (3) abnormal cases. Nevertheless, from the medical diagnosis viewpoint, a minimum requirement corresponds to the general two-class problem of correct separation between normal from abnormal cells.
MODIFIED PARTICLE SWARM OPTIMIZATION FOR AN OPTIMAL FEEDER-SWITCH RELOCATION
Authors: TUPPADUNG YUTTHAPONG , KURUTACH WERASAK
Published: April 2008

This paper presents an optimal feeder-switch relocation that is applied by modified Particle Swarm Optimization (MPSO). An inertia weight in Particle Swarm Optimization (PSO) is modified to find the best patterns of distribution configuration. MPSO performance is evaluated by comparison with the conventional inertia weight method. Six different benchmark functions with asymmetric initial range settings are selected as testing functions. A nonlinear inertia weight function is applied in this paper. The results of the experiment illustrate the advantage of MPSO. The optimal feeder-switch relocation in a radial distribution system is used to evaluate the MPSO performance. The results show that MPSO can identify suitable switch locations, based on minimum customer interruption costs.
EFFECTS OF MAGNETIC AND ELECTRIC FIELDS ON THE HYDROGENIC IMPURITY IN AN ELLIPSOIDAL PARABOLIC QUANTUM DOT
Authors: KASAPOGLU E. , SARI H. , SOKMEN I.
Published: April 2008

The binding energy of a hydrogen-like impurity in an ellipsoidal parabolic quantum dot under the magnetic and electric fields have been discussed by using the effective mass approximation and the variational method. We have calculated the effects of the magnetic and electric fields on the binding energy of donor impurities in the quantum dots with different confinement potentials. We conclude that the structural confinement is very effective, and especially in the weak confinement potential case the magnetic field dependence of the donor binding energy is more pronounced.
DC CONDUCTION MECHANISMS IN Al–SnO2–Al STRUCTURE DEPOSITED BY THERMAL EVAPORATION
Authors: ANWAR M. , GHAURI I. M. , SIDDIQI S. A. , AFZAL NAVEED
Published: April 2008

The DC conduction mechanisms in metal–insulator–metal sandwich structure based on amorphous thin films of SnO 2 have been studied in the thickness range 100–400 nm, in the substrate temperature range 293–543 K, and in the annealing temperature range 473–773 K, and the results are discussed in terms of current theory. It is observed that at low field and low temperature the conduction mechanism is found to obey the hopping model, at higher temperature the conduction takes place by transport in the extended states but at high field the main barrier lowering effect is associated with localized centers. The increase in electrical conductivity with film thickness is caused by the oxygen vacancies and [Formula: see text] defects which generate carriers in the films. The increase in electrical conductivity due to an increase in substrate temperature is ascribed to the increasing concentration of ionized donors and hoping of electrons between metal ions in two different valence states. The formation of tin species of lower valence states and doubly ionized oxygen vacancies are thought to be responsible for the increase in electrical conductivity at higher annealing temperature.
ELECTRIC DOUBLE LAYER CAPACITORS WITH CARBON NANOTUBES ELECTRODES AND GEL POLYMER/POLYACID ELECTROLYTES
Authors: ZHANG YANPING , PAN LIKUN , GAO YANG , ZHANG ZHEJUAN , SUN ZHUO
Published: April 2008

Electric double layer capacitors (EDLCs) with carbon nanotubes (CNTs) film electrodes and gel polymer/polyacid electrolytes have been demonstrated. The low-cost CNTs film is directly grown on Cu – Ni current collector by low pressure and low temperature thermal chemical vapor deposition. The electrolytes consist of gel polymer poly(vinyl alcohol), polyacid phosphomolybdic acid (PMA) with different concentrations from 10 to 40 wt.% and KCl . The electrochemical measurement of the EDLCs by cyclic voltammetry and chronopotentiometry shows that gel polymer/polyacid electrolytes can work stable at a wide potential range of -1.5 to 1.5 V and EDLCs with electrolytes containing 30 wt.% PMA exhibit optimum capacitive behavior with 8.09 F/g specific capacitance.
INFLUENCE OF CADMIUM SALTS ON A MODIFIED CHEMICAL BATH DEPOSITION OF CADMIUM SULFIDE THIN FILMS
Authors: XU X. B. , HUANG S. Y. , CHU J. B. , ZHU H. B. , SUN Z. , CHEN Y. W. , HUANG S. M.
Published: April 2008

A simply modified bath deposition technique has been successfully used to deposit uniform CdS thin films using cadmium chloride or cadmium acetate as the cadmium ion source, and thiourea as the sulfur source on glass substrates. Both the traditional magnetic agitation and the frequent substrate vibration by hand were done simultaneously during the deposition. Various properties of the deposited films such as surface morphology, crystallinity, and optical properties were investigated. The CdS films deposited from cadmium acetate show a good crystallinity and exhibit a preferential orientation along the hexagonal (002) direction. Their surface morphologies are more homogeneous with smaller grains than those from cadmium chloride. The CdS films prepared from both cadmium ion sources present a high optical transmission (more than 80%) in the visible range with the band gap value of about 2.4 eV. The substrate vibration reduces the formation and residence of gas bubbles on the glass substrate during growth and resulted in deposition of CdS thin films with high quality. XRD, SEM, and UV–Vis measurements have provided the supported data. The fundamental CBD growth mechanisms involving different cadmium salts are discussed.
ADSORPTION AND DISSOCIATION OF PH3 ON SiGe(100) (2 × 1) SURFACE
Authors: TÜRKMENOĞLU MUSTAFA , KATIRCIOĞLU ŞENAY
Published: April 2008

The most stable structures for the adsorption and dissociation of phosphine ( PH 3) on SiGe (100) (2 × 1) surface have been investigated by relative total energy calculations based on density functional theory. According to the optimization calculations, PH 3 is adsorbed on the Si (down) and Ge (down) site of the Ge – Si and Ge – Ge dimers on SiGe surface, respectively. The PH 2 and H products have been found to be thermodynamically favored in the dissociation path of PH 3 on SiGe surface when the system is thermally activated. Although PH 3 is adsorbed on the Ge – Ge and Ge – Si dimers directly, it dissociates on the SiGe surface by passing through a transition state. The asymmetric Ge – Si and Ge – Ge dimers on SiGe surface are found to be approximately symmetric after the dissociation of PH 3 on the surface. The present work has showed that PH 2 prefers to be adsorbed on Ge site of the Ge – Si dimer. Therefore, the adsorption of PH 2 on Ge site of the Ge – Si dimer, while PH 3 being dissociated on the Si site, has indicated the migration of PH 2 on SiGe surface.
The Texture of a Slate From Nantlle, Caernarvon, North Wales
Authors: Oertel Gerhard , Phakey Prem P.
Published: April 2008

A specimen of Cambrian slate from the slate belt in North Wales has been thinned by the ion bombardment
technique to produce an ultrathin section with the specimen plane normal to the cleavage plane. This specimen
has been investigated with the electron microscope by electron transmission. Selected area diffraction patterns allow
identification of individual sheet silicate grains. The pole figures of the basal planes of two sheet silicate minerals,
muscovite and chlorite, have been measured with an X‐ray pole‐figure goniometer and both show an elongated
maximum normal to the slaty cleavage, with orthorhombic symmetry. While the preferred orientation could be the
result of mechanical rotation of rigid flakes in a deforming matrix, the texture (the overall pattern due to the
shapes and sizes of grains and their angular relations to each other) can only be explained if considerable recrystallization
is assumed. It is tentatively proposed that local dissolution at points of stress‐concentration with
simultaneous redeposition of the dissolved material in less stressed regions may have allowed closely packed grains
to act as if they were mechanically rotating rigid flakes, yet to accommodate their shapes enough to prevent interlocking.
X‐Ray Analysis of a Quartz Fabric From the Sambagawa Crystalline Schist, Japan
Authors: Hara Ikuo , Paulitsch P.
Published: April 2008

An X‐ray fabric analysis of quartz grains from the Sambagawa crystalline schist, Japan, whose c‐axis fabric
(optically measured) was regarded as corresponding to an ultimate steady‐state pattern of preferred orientation
of c‐axes developed by the approximately non‐rotational two‐dimensional strain under the Sambagawa metamorphicconditions,
has been made by a texture goniometer for reflection. It has been clarified that [0001] and [10]

directions are preferably oriented in the plane of the longest and shortest principal axes of the strain ellipsoid of
mean strain of the system concerned and at the angles of ca. 35° and ca. 17° to the shortest principal axis
respectively.
The Rolling Texture of Cu3Au
Authors: Vandermeer R. A. , Ogle J. C.
Published: April 2008

The rolling texture of Cu3Au has been investigated by X‐ray diffraction. At room temperature, independently of the degree of long‐range order, Cu3Au developed a mixed or “hybrid” texture; it consisted of elements of each of the prototype face‐centered cubic textures characterized by pure copper and 70/30 brass. However, on rolling at 77 K the alloy in the disordered state was significantly more “brass‐like” than when it was fully ordered. This result may be explained by a stacking fault energy texture reversal analogous to that observed in wire drawing at low SFE. The lack of twinning (or other deformation mechanism such as slip by partial dislocations) in the ordered alloy could be responsible for this reversal.
The Nucleation of Recrystallisation and the Development of Textures in Heavily Compressed Iron‐Carbon Alloys
Authors: Dillamore I. L. , Katoh H. , Haslam K.
Published: April 2008

Quantitative studies of textures developed in compressed iron–0.02%C and iron–0.14%C alloys before and after annealing have allowed theoretical predictions based on homogeneous plasticity theory to be assessed. It is concluded that qualitatively the theory is very good but predicts rates of texture development rather higher than those observed. The prediction of the theory that orientations on a line joining [110] and [411] should have a tendency to split into two components on deformation and form transition bands, which may be important in nucleating recrystallisation, has been confirmed by the results of the annealing experiments.
The Development of the Rolling Texture of Iron Determined by Neutron‐Diffraction
Authors: Schläfer D. , Bunge H. J.
Published: April 2008

The development of the rolling texture of a low carbon steel was investigated by neutron diffraction calculating three‐dimensional orientation distribution functions. The textures consist of two limited fibre axis components A and B centered about
and respectively with an angle of rotation of about 70∘. For rolling degrees larger than 50% the intensity of the fibre axis component A is being modulated so as to favour the orientation . The texture may be considered as inverse to the low concentration brass texture in the sense of interchanging rolling and normal directions. It may be understood in terms of {110}〈111〉—glide and {112}〈111〉—twinning.
Texture Control and the Yield Anisotropy of Plane Strain Magnesium Extrusions
Authors: Dillamore I. L. , Hadden P. , Stratford D. J.
Published: April 2008

The textures developed in magnesium, annealed after both hot and cold extrusion under essentially plane strain
conditions, have been qualitatively accounted for in terms of the operative deformation modes. It is found that the
main features of both textures are explained by the operation of {102} and {101} twinning together with basal slip,
but there is an important component of the hot extrusion annealing texture not found in the cold extrusions
texture which can only be explained by the action of {100} or {101} slip.The strength of the extruded and annealed material has been studied under various stress systems and initial
yield loci have been plotted. Complete crystal orientation distribution functions were used to compute theoretical
yield loci for comparison with the experimental results in order to assess the possibility of relating texture and
properties in hexagonal metals. It was found that the theory gave remarkably good agreement with experiment.
The assumptions made and the terms under which they apply are discussed.
Automatic Drawing of Stereographic Nets
Authors: Vadon A. , Ruer D. , Bäro R.
Published: April 2008

The present paper describes a computer program for the automatic tracing of new stereographic nets aimed at the description of pole figures.
A System of FORTRAN for Three‐Dimensional Texture Analysis
Authors: Jura J. , Pospiech J. , Bunge H. J.
Published: April 2008

A system of FORTRAN programmes is being described which allows most of the standard problems of three‐dimensional texture analysis to be easily carried out. It requires about 25 K memory space and it may easily be enlarged by incorporating further subroutines.
Texture of Metals
Authors: Hu Hsun
Published: April 2008

A condensed review of casting, deformation, and annealing textures of polycrystalline metals and alloys is presented. It is intended to provide an informative but simplified reference for researchers, engineers, and students who are seeking quick information on the development of textures in various metal objects, and for those who are primarily interested in the textures of non‐metallic materials, but wish to acquire a general background knowledge on the texture formation in metals.
The Problem of Texture in Mössbauer Spectroscopy
Authors: Kreber E. , Gonser U.
Published: April 2008

In Mössbauer spectroscopy it is desirable to work with single crystals or with polycrystalline material of random orientation. The actual, most occuring, case of preferred orientation (texture) and its influence on the relative line intensities of hyperfine split Mössbauer spectra is analysed. Texture information which can be obtained from such an analysis is demonstrated with variously prepared barium ferrite (Ba Fe12 O19) samples.
Cyclic Textures in Aluminium Wires
Authors: Schläfer U. , Bunge H. J.
Published: April 2008

Three‐dimensional orientation distribution functions were calculated from neutron diffraction pole figures of unwound
cylinders taken at different distances from the centre of cold drawn Al‐wires. Their features change from
the axially symmetric type at the very centre of the wire towards a texture near to the rolling type at the surface.
Relations between the three‐dimensional function and ordinary fibre texture pole figures were used to study the
dependence of the textures on certain processing variables for cold drawn as well as recrystallized wires.
The Development of Texture in Copper and Copper‐Zinc Alloys
Authors: Kallend J. S. , Davies G. J.
Published: April 2008

The crystallite orientation distribution function has been determined for cold‐rolled copper, copper‐10 per cent
zinc and copper‐30 per cent zinc (α‐brass) at cold reductions of 0, 20, 40, 60, 80, 90 and 95 per cent. The copper
texture exhibits a steady development and contains a tube of orientations between limits which have previously
been shown to be stable during multiple slip processes ({110}〈112〉 to {4411}〈11118〉). The textures of the
copper‐zinc alloys both show a similar initial development to that of copper but a transition occurs above a
reduction of about 40 per cent. This indicated that an additional deformation mode had become active. The
features of the transition are consistent with those expected if the additional deformation mode were mechanical
twinning. The development of the basic texture (pure‐metal type) is in agreement with predictions based on the
assumption of multiple slip conditions incorporating a considerable amount of cross‐slip.
Topographic Arrangement of Crystallite Orientations in Rolled Copper
Authors: Gotthardt R. , Hoschek G. , Reimold O. , Haessner F.
Published: April 2008

In single and polycrystalline copper rolled to a reduction of 95 %, the topographic arrangements of crystallite
orientations were determined over large areas by means of electron microscopy. Correlated data on orientation,
diffraction site, and transmission pictures in three cross‐sections perpendicular to the normal, rolling and transverse
directions were obtained and evaluated. These results were complemented by X‐ray studies of the texture. The
rolled polycrystalline structure consists of roughly disc‐shaped regions of uniform orientation which are fairly
strongly misoriented with respect to each other. The planes of the discs lie paral.lel to the rolling plane. Within these
regions of uniform orientation lie elongated subgrains extended in the longitudinal and transverse directions. In a
surface layer of a few microns thickness the dryly rolled single crystals have essentially a (100)[011] texture. This is
independent of the orientation of the interior of the material. The observed structures are discussed with respect to
possible formation mechanisms.
Neutron Diffraction Texture Analysis of 1 Vol.% Cu in Aluminium
Authors: Brokmeier H.-G. , Bunge H. J.
Published: April 2008

Neutron diffraction texture determination was carried out in two‐phase composites,
AlCu1%, prepared by powder metallurgical methods and extruded 84 and 89%
respectively. The texture of the minor Cu‐phase can be measured with a sufficient
degree of accuracy within reasonable time. This texture is weaker than the texture of
the Al‐matrix phase corresponding to the lower internal deformation degree of the
former one. It is estimated that the method can be extended to even lower volume
fractions of the second phase.
Some Information on Quaternions Useful in Texture Calculations
Authors: Morawiec A. , Pospiech J.
Published: April 2008

Crystal orientation is described by a rotation which can be expressed by a great
number of different sets of parameters. Among these, the quaternion representation
is the most economic one. The basic properties of quaternions are briefly
summarized and their interrelationships with other orientation coordinates such as
rotation axis and angle, the orientation matrix, and the Euler angles are given.
Young′s Modulus of Iron–Silver Sheet Composites
Authors: Ratke L.
Published: April 2008

Layered iron–silver sheet composites were prepared by hot extrusion and cold
rolling of powder mixtures of various compositions. These in‐situ deformation
composites show a strong increase in Young′s Modulus on addition of silver to pure
iron and their elastic behaviour is anisotropic in the rolling plane. The deformation
dependence of Young′s Modulus as well as the planar anisotropy are discussed with a
new theory of Bunge, which covers the experimental findings sufficiently.
Texture Investigations by Neutron Time‐of‐Flight Diffraction
Authors: Feldmann K.
Published: April 2008

For the majority of isotopes the thermal neutron absorption cross section is two or
more orders lower than that for X‐rays. This makes neutron diffraction well‐suited
for bulk texture investigations. Some characteristics of neutron diffraction are
discussed. The principles of neutron time‐of‐flight diffraction are described. The pole
figure determination by means of TOF technique is considered. The main parameters
of the present Dubna texture facility are given. Further developments of the
experimental technique are considered. The application of the TOF technique for
inverse pole figure measurement is discussed as an approach to direct observation of
the texture forming process. The magnetic moments of neutrons can be used to study
magnetic textures. Two different techniques are discussed.
The Magnetic Properties of Textured Fine Particle Systems
Authors: Chantrell R. W.
Published: April 2008

The magnetic properties of fine particle systems are strongly dependent on two types of texture. The
first is an orientational texture characteristic of the angular dispersion of the easy anisotropy axes and
the second is a spatial texture characteristic of the physical microstructure of the system. The effects of
texture on the properties of both fluid and solid dispersions of fine particles can be very pronounced.
The paper reviews some recent studies illustrating these effects, with particular emphasis on the
behaviour of recording media and magnetic fluids.
Neutron Depolarization in Submicron Ferromagnetic Materials
Authors: Rekveldt M. Th.
Published: April 2008

The neutron depolarization technique is based on the loss of polarization of a polarized neutron beam
after transmission through ferromagnetic substances. This loss, caused by Larmor precession in
individual domains, determines the mean domain size, the mean square direction cosines of the
domains and the mean magnetization. The method is complementary to the neutron scattering
technique with respect to the size of the inhomogeneities to be determined and the dynamic range
accessible. Only the static applications of the method in studying domain structures are considered.
As examples will be treated metal foils under stress, oriented ferroxdur permanent magnets, soft
ferrites, recording tapes and thin films. In most of these examples magnetic correlations between
neighbouring domains are subject of study.
Influence of Grain Boundary Characteristics and of Chemical Parameters on Abnormal Grain Growth in Fe–3% Si Sheets
Authors: Rouag N. , Penelle R.
Published: April 2008

The purpose of the present study was to precise mechanisms at the origin of the exaggerated Goss
grain growth of Fe–3% Si sheets, grade Hi–B. It has been pointed out that at the primary
recrystallized state, the Goss grains which belong to the small grain class are present through the
whole sheet thickness. In presence of AlN and MnS inhibitors, their growth during the anisothermal
secondary recrystallization annealing is due to the high mobility of the special C.S.L. boundaries;
their subsequent expanse at the fifth of the sheet thickness is favoured by purification of the sheet.
Indeed, after dissociation of AlN and MnS precipitates at high temperature, a concentration gradient
in sulfur and in nitrogen due to the reducing hydrogen atmosphere has been observed in subsurface
thanks to SIMS experiments, such as general and C.S.L. boundaries can easily move whereas those at
the center of the sheet are more dragged.
Effects of Laser Processing on Domain Wall Motion in Grain‐Oriented Silicon Steel
Authors: Barradi T.
Published: April 2008

The influence of laser irradiation spacing on the shape of the so‐called “saw‐tooth” domains is
reported. Dynamic behavior under an external field, applied in the rolling direction, is investigated
using a suitable imaging package developed for magneto‐optical Kerr effect studies. Results relative to
irradiated and non‐irradiated commercial Hi–B specimens are confronted and the incidence on core
losses is discussed.