bluuebunny/crossref_metadata_2025 huggingface dataset:
Use of Electrically Enhanced Aerosol Plasma Spectroscopy for Real-Time Characterization of Beryllium Particles
Authors: Chen M-D , Smithwick RW , Hinton R
Published: May 2009

The best warning of human exposure to elevated toxic aerosol particles is a monitor that can provide a near-real-time alarm function. Use of surrogate indices such as particle-number concentration, mass concentration, and/or other flow-diagnostics variables is ineffective and could be costly when false positives do arise. We have developed a field-portable system specifically for monitoring beryllium particles in the air in near real-time. The prototype monitor is installed on a two-shelf handcart that can be used in workplaces involving beryllium extraction, machining, and parts fabrication. The measurement involves no sample preparation and generates no analytical waste. The operating principle of the monitor is electrically enhanced laser-induced electrical-plasma spectrometry assisted with aerosol-focusing technology. Performance data of the monitor indicate a dynamic range spanning over four orders of magnitude, and the monitor is capable of detecting an airborne beryllium concentration of 0.05 μg m-3. In reference, the Department of Energy (DOE) standard for beryllium is 0.2 μg m−3 within an 8-h average, while the Occupational Safety and Health Administration standard for beryllium is 2 μg m−3. In addition, the monitor is capable of simultaneous detection of multiple elements using an Echellette spectrometer if needed. The capability of simultaneous detection provides a convenient means for positive identification and possible quantification of multiple elements in near real time. We present the instrument development and calibration data and results from field demonstration conducted at a DOE facility in Oak Ridge, Tennessee.
An Experimental and Numerical Study of the Fracture Strength of Welded Structural Hollow Section X-Joints
Authors: Björk T , Marquis G , Pellikka V , Ilvonen R
Published: May 2009

The effect of the geometry and material properties on the fracture strength of welded X-joints fabricated from structural hollow section (SHS) profiles has been studied experimentally and by using nonlinear finite element analysis (FEA). The current paper focuses on four joints tested at −40°C. This was one part of an extensive series of laboratory experiments performed at temperatures +20°C… −60°C. At sub-zero temperatures the primary fracture mode was mainly ductile followed by final brittle failure. The radius and material properties in the corner area of a SHS are dependent on the fabrication method of the SHS. In cold-formed sections the corner radius is typically large and the yield strength is greater than the nominal yield strength of the base material. This bigger corner radius can provide different stiffness and load carrying capacity as compared to joints fabricated from hot-formed sections. Numerical simulation and experimental tests focused on the importance of this corner effect and the separate role geometry, yield strength, and fracture toughness on the total fracture strength of the joint.
Development of a Circumferentially Throughwall Cracked Tube Specimen for Fatigue Crack Growth Rate Tests
Authors: Young BA , Van Der Sluys WA , King PJ
Published: May 2009

This paper describes the development of a nonstandard specimen geometry for fatigue crack growth rate studies. Most fatigue crack growth rate data, available in open literature, for Alloy 690 and Alloy 600 were developed using standard, thick section C(T) specimens. Recently a need arose to study a circumferentially throughwall cracked tube specimen. The goal of the development was to use this tube specimen to determine any effects of section thickness or grain size on corrosion enhancement of fatigue crack growth rates in a simulated pressurized water reactor (PWR) primary side environment. Along with the final specimen geometry, the stress intensity equation and crack length monitoring equation are discussed. The stress intensity equation was converted to a standard polynomial equation in order to use a conventional automated fatigue crack growth rate software package. Symmetry arguments were made to justify the use of direct current potential drop (DCPD) and the use of the standard Johnson's equations for measuring crack lengths. Also, some discussions of the validity requirements for this geometry are presented such as stress intensity limits to remain with linear elastic fracture mechanics (LEFM) bounds and crack length limits to avoid excess bending stresses. A baseline test program was conducted on Alloy 690 tube specimens in ambient air and these results were compared with literature data. Also, a sensitivity investigation was preformed to determine the error between the polynomial equations developed and the actual equations in literature. The results of this study confirmed that a circumferentially cracked tube specimen could produce valid fatigue crack growth rate data.
Electrokinetic Dewatering and Sedimentation of Dredged Contaminated Sediment
Authors: Chung HI , Kamon M
Published: May 2009

This research focuses on electrokinetic dewatering and settling of contaminated sediment. A series of laboratory experiments with different magnitudes of applied voltage is performed with artificially made contaminated sediment mixed with contaminant. Investigated parameters in experiments are settlements of the slurry specimen, volumes of water extracted from the slurry specimen, and the changes in fluid content of the specimen. The results show that the sedimentation rate and velocity are varied and controlled by the applied voltage. From the test results, a significant investigation is derived for the mechanisms associated with dewatering and sedimentation of contaminated sediment. A coupled effect of electrokinetic dewatering and settling processes is investigated.
Electrokinetically Enhanced Settlement and Remediation of Contaminated Sediment
Authors: Chung HI , Sills GC , Kamon M
Published: May 2009

Electrokinetic technique has been used in sedimentation at mining applications as a volume reduction for slurry tailing wastes. This technique has been used in remediation for environmental application as a potential in-situ remediation method for contaminated soils and wastes. Thus electrokinetic technique can be used in sedimentation and remediation of sediments. A regulated constant voltage was applied on the testing sample, directed upward, top cathode (−) and bottom anode (+) during electrokinetic sedimentation process. On the other hand, constant voltage was applied on the testing sample, directed downward, top anode (+) and bottom cathode (−) during electrokinetic remediation process. This means that the polarity reversal was employed. The time dependent settlement and concentration due to electrophoresis and electro-osmosis was measured on an hourly basis. The sedimentation rate of specimen and removal rate of contaminant in contaminated sediment were increased with increasing of applied voltages.
Permeability Characteristics of Lake Kojima Sediment and Their Improvement
Authors: Munehide I , Ryouichi I , Akiko H , Tomoyuki I , Takeo A
Published: May 2009

As lake sediments are one of the causes of eutrophication, their removal and effective use has been considered. When they are used as soil in a land, proper permeability is required. However, soil permeability has not completely been understood due to diversity of clays and organic compounds. We clarified permeability characteristics of Lake Kojima sediment, nonswelling clayey soil, by measuring saturated hydraulic conductivity (K). A decrease in K during percolation of dilute electrolyte solution was small when Ca was adsorbed by the soil; K became 3.4×10−5 cm/s at pH 5, 2.9×10−5 cm/s at pH 7, 7.5×10−6 cm/s at pH 9, and 2.3×10−5 cm/s at pH 11 after pure water percolation. Although the permeability tended to decrease as pH increased, K at pH 11 became larger than that at pH 9 due to chemical reaction between soil particles and Ca. On the other hand, when Na was adsorbed, K drastically decreased with pH increase; K became 7.1×10−6 cm/s at pH 5, 3.1×10−6 cm/s at pH 7, 1.7×10−7 cm/s at pH 9, and 1.3×10−7 cm/s at pH 11 after pure water percolation. The obtained results could be explained qualitatively by the theory. Next, an improvement method of permeability of Lake Kojima sediment with hydrated lime and gypsum were investigated. Three application methods were compared in the saturated hydraulic conductivity experiment; mixing, surface distribution and solution infiltration. Hydrated lime application with mixing maintained high hydraulic conductivity. The soil structure was supposed to be stabilized by chemical reaction between soil and heterogeneously distributed hydrated lime. On the other hand, gypsum application with solution infiltration maintained the same hydraulic conductivity as that of hydrated lime application with mixing. In that case, electrostatic adsorption of Ca was considered to generate flocculation and kept high permeability.
Modeling TPH Desorption in Unconsolidated Dune Sand during Remediation Using Dual-Equilibrium Desorption (DED) Model
Authors: Manhart CS , Chaney RC
Published: May 2009

The verification of the cleanup of dune sands from a dissolved phase petroleum hydrocarbon plume at an active service station site undergoing ozone treatment is being accomplished through soil and groundwater sampling. We hope to use modeling by the dual-equilibrium desorption (DED) model in order to determine when remedial goals negotiated with the regulatory agencies have been met. The site is located in the harbor area of Crescent City, California in an area underlain by dune sands of marine origin. During remediation of sorbed-phase gasoline and diesel range organics (GROs and DROs) and dissolved-phase methyl tertiary butyl ether, target compounds, intrinsic indicators, by-products, and bacterial composition were monitored in the area groundwater and soil. At present, this monitoring has been employed to establish the degree of cleanup of the sands. In this paper the use of the DED model to verify the degree of cleanup of the sands is presented. Results indicate rapid degradation of the target compounds from the dissolved phase with gradual degradation from the sorbed phase. Degradation of the sorbed phase GROs and DROs was indicated by periodic spikes in dissolved-phase concentrations, which are interpreted as representing desorption events. Co-located soil and groundwater samples were collected at intervals of approximately six to nine months. Results from this verification sampling were modeled using the DED. We hope to find a tool that an investigator at a typical underground storage tank site can use to gauge the success of remediation systems. So far, the DED appears to correlate with samples collected using standard field techniques. The use of this methodology has application in establishing the degree of cleanup of contaminated sandy dredge sediments.
Cadmium Transport in Volcanic Ash Soil During Citric Acid Solution Flow
Authors: Mizoguchi M , Abe Y , Yamaguchi N , Miyazaki T
Published: May 2009

Cadmium contamination of soil is one of the most serious environmental problems in Japan. As basic research toward the development of a decontamination method to remove cadmium from soil, cadmium transport has been measured in a volcanic ash soil during citric acid solution flow. After a soil column that was polluted artifically by cadmium nitrate was saturated with distilled water, citrate solution was passed through the soil column. Leachate from the soil column was collected for the measurement of cadmium concentration. At the end of the flow experiment, the soil column was sliced into 2-cm-thick pieces and the residual cadmium in soil was analyzed. As a result, it was found that the higher the concentration of citrate, the faster the cadmium discharged from the soil. This result can be explained in terms of the downward movement of the soluble complex of citrate with cadmium in the soil.
Shielding Calculations for the Upgrade of the HFIR HB 2 Beam Line
Authors: Slater CO , Selby DL , Bucholz JA , Robertson JL , Crow ML
Published: May 2009

Experimental facilities at the Oak Ridge National Laboratory's High Flux Isotope Reactor are being upgraded through the redesign of beam tubes supplying neutrons to those facilities. In support of the shield design for one of the beam lines HB-2, calculations were performed to determine dose rates outside the shielding as well as background radiation levels at various locations around the instrumentation. Low-power (10 % power) as well as full-power measurements were made at key locations, and calculated results were compared with corresponding measured results. This paper describes the calculations and compares the measured and calculated results. Most of the measured results, when normalized to the full-operating-power level, compared favorably with the calculated results. One differed by a factor of 2.5, and another differed by a factor of 6. Based on this agreement, one can infer that reasonable calculations for some three-dimensional shield designs can be performed using two-dimensional methods and two-dimensional approximations to the three-dimensional geometry. The results confirmed the adequacy of the design.
Spray Retention Models for Arable Crops
Authors: Forster WA , Kimberley MO , Steele KD , Haslett MR , Zabkiewicz JA
Published: May 2009

A model has been developed explaining 92 % of the variance in spray retention by individual plants. The effects of formulation and plant morphology were represented as a logistic function, because this can accommodate retention close to 100 or 0 % whereas an additive model cannot. All inputs for the current model, except for the plant morphology factor, Mp, could be readily measured. Mp could be estimated by a linear regression relating Mp to the leaf surface roughness, as determined by the contact angle of a droplet of 50 % acetone on the leaf surface. The use of a logistic function, and inclusion in the model of total plant area, plan area, and contact angle to account for plant morphology, has provided an improved, practical, easily used universal agricultural spray retention model needing few inputs.
A Comprehensive Examination of the Internal Angle of Gyration for the Superpave Gyratory Compactor
Authors: Hall KD
Published: May 2009

The Superpave gyratory compactor (SGC) is the “centerpiece” of the Superpave system. Hot-mix asphalt (HMA) specimens are compacted in the laboratory using the SGC through the application of pressure and an applied angle of gyration. The original compaction specification for the SGC requires the angle of gyration to be 22°±0.35 mrad (1.25±0.02 deg), measured externally to the compaction mold. Due to concerns regarding the inability of different compactors to produce HMA specimens with similar density, the Dynamic Angle Validation (DAV) kit was developed to measure the angle of gyration internally, or inside the mold. The DAV requires the use of HMA for the internal angle determination; logistical concerns and other issues led to the introduction of devices—the Rapid Angle Measurement (RAM) and the Hot-Mix Simulator (HMS)—which mechanically simulate the load placed on the SGC by the mix being compacted. This paper presents a summary of the state-of-the-practice concerning the internal angle of gyration and addresses potential strategies for implementing an internal angle specification into routine Superpave mixture design and quality control practices.
Tweaking the System: Modifications to the Superpave Mix Design System
Authors: McDaniel RS , Hansen K , Newcomb DE , Decker DS
Published: May 2009

A recent survey by the Association of Modified Asphalt Producers showed that a majority of states now use some form of PG+ specifications, meaning that they have added tests or requirements to the Performance Graded (PG) binder specification. The situation for the Superpave mix design system is analogous. States have added requirements, changed various parameters, and implemented or declined to implement revisions to the AASHTO specifications. In 2004 and 2005, the National Asphalt Pavement Association and Federal Highway Administration sponsored a series of regional workshops across the country to assess the current state of the practice with Superpave and hot mix asphalt in general. Four workshops were held in conjunction with the regional asphalt user producer group meetings. At these workshops, industry and agency personnel shared their experiences with Superpave. One key objective of the workshops was to determine what changes had been made to the mix design system and the rationale for those changes. This paper summarizes the changes that have been made to the system across the country, giving a snapshot of the current state of the practice.
Study of Vacuum Carbon-Deoxidization of High Carbon Chromium Bearing Steel
Authors: Zheng L , Minghua X
Published: May 2009

This paper describes the negative influence of high residual aluminum which is used as a deoxidant in the steel and raises the newest control requirement for high carbon steel on residual aluminum. By means of thermodynamic calculation and production practices, the total oxygen (Σ[O]) in the steel can be 10 ppm through carbon-oxygen reaction under the conditions of high vacuum, proper top slag composition, and argon stirring during ladle refining/vacuum degassing (LF/VD) processes of high carbon chromium bearing steel. Meanwhile, the size of D-type inclusion in the steel is obviously reduced. Thus, the purity of the bearing steel is improved. Since the consumption of aluminum used for deoxidation is reduced, the unit cost of bearing steel is obviously reduced.
Yield Point Standardization
Authors: Taraldsen A
Published: May 2009

The yield point, that is, the stress at which a steel starts to suffer a pronounced permanent set, is a very important property. There is in international standardization a dilemma about whether to use upper yield point (ReH) or lower yield point (ReL) as the characterizing yield point value in steel standards and in practical material testing. This dilemma may to a great extent be due to the people involved in standardization themselves exaggerating the difference between ReH and ReL. Both yield point values are dependent on the strain rate, which again may be greatly influenced by the compliance of the testing system. Some confusion may exist regarding the term “upper yield point” as compared with the term “yield point.”
Evaluation of Some Factors Affecting Measurements of Slip Resistance of Shoe Sole Materials on Floor Surfaces
Authors: Irvine CH
Published: May 2009

Research done at Liberty Mutual Research Center consisted of 7090 slip tests in an attempt to show it is possible to determine differences in the slip-resistant qualities of various shoe soles. The tests included seven floor materials, eleven shoe sole materials, three sole pressures on wet and dry floors, and four widely different relative humidities. Thirteen operators took the measurements, using the Horizontal Pull Slipmeter. The measurements proved to be sensitive to relative humidity, sole pressure, repetitive measurements, and wet and dry conditions. Each operator demonstrated that consistent measurements can be taken with the Horizontal Pull Slipmeter. The conclusion is that it is possible to identify shoe sole materials that have desirable slip-resistant qualities for various floor surfaces under wet and dry conditions.
A Note on the Measurement of Proportional Limit Under Multiaxial Stresses
Authors: Clough RB
Published: May 2009

Theoretical definitions of the multiaxial plastic flow surface are exact; however, ambiguities arise in the experimental measurement. A new method for measuring the multiaxial flow surface based on maximum elastic stress rate is proposed which eliminates these ambiguities. It is applied to biaxial yielding.
Tensile-Shear Bond Strength and Failure Between Aggregate and Mortar
Authors: Kao C-C , Slate FO
Published: May 2009

The purpose of this study was to investigate the tensile-shear bond strength and failure of the mortar-aggregate interface. The techniques used are reported. The results indicate that the Mohr failure envelope in the tension-shear quadrant is almost a straight line and that the failure is essentially tensile in nature.
Laboratory Compaction Test Methods and Results Compared with Attainable Field Densities on Subbase Materials
Authors: Hoffman GL , Cumberledge G , Koehler WC
Published: May 2009

With the extensive use of aggregate material in highway construction (primarily subbase) in Pennsylvania, the Pennsylvania Department of Transportation (PennDOT) initiated an indepth analysis of results of laboratory and field compaction tests on aggregates. This study determined what field and laboratory tests are best correlated to produce the optimum compaction control technique for subbase materials.

Results of approximately 500 sand cone and nuclear field densities in crushed limestone, gravel, and slag material at 17 construction sites throughout the state are summarized and compared. Laboratory density tests on material from each of these field test sites include vibratory, standard moisture-density, modified moisture density, the Marshall test, and the vibratory hammer test. Regression correlation analyses are performed between maximum attainable field and laboratory densities. Estimating linear equations for predicting relationships between field and laboratory maximum densities are developed and their significance is discussed.
Monitoring to Determine the Dynamics of Fatigue Testing
Authors: Collacott RA
Published: May 2009

These investigations were begun to monitor the sonic response during the fatigue life testing of cantilever specimens; they led to the discovery that the power spectral density from the second overtone (3 × fundamental) changed with time, originally exceeding that from the fundamental. Overtones may have a pronounced influence on fatigue testing, and the experimental results should lead to consideration of the possible dynamic effects introduced by such overtones. Tests show that changes can be detected as a consequence of work hardening and crack growth. Possibly this method may be developed as a nondestructive testing technique.
Guard-Gap Correction for Guarded-Electrode Measurements and Exact Equations for the Two-Fluid Method of Measuring Permittivity and Loss
Authors: Endicott HS
Published: May 2009

Empirical equations are developed for evaluating the guard-gap correction for guarded electrodes, taking into account the ratio of gap width to electrode spacing, the ratio of the electrode thickness to the gap width, and the permittivities of the material in the gap and between the electrodes. Exact equations are then developed for calculating specimen permittivity, thickness, and dissipation factor from two-fluid measurements, for the first time taking into account the change in effective area when the specimen is inserted between the electrodes, the dissipation factor of the specimen, and that of the liquid. Series resistance and inductance and change in spacing of the electrodes between the first and second set of readings are also taken into account. The accuracy of the equations is estimated to be such that they will not significantly affect the accuracy of two-fluid measurements. Sample calculations are included.
Asphalt Cements: Pen-Vis Number and Its Application to Moduli of Stiffness
Authors: McLeod NW
Published: May 2009

Because of the false softening points of many Canadian asphalts due to the waxy crude oils from which they are derived, highly erroneous values for Pfeiffer's and van Doormaal's penetration index as a quantitative measure of the temperature susceptibility of asphalt cements occur. Consequently, it has been necessary to develop a different quantitative measure for temperature susceptibility, pen-vis number, which is based on an asphalt cement's penetration at 77°F (25°C) and viscosity in centistokes at 275°F (135°C). The development of the pen-vis number of an asphalt cement and its application to the determination of moduli of stiffness of asphalt cements and asphalt paving mixtures are described.
A Constant Tensile Stress Creep Testing Machine
Authors: Hostinský T , Čadek J
Published: May 2009

A new constant tensile stress creep testing machine is described. The machine makes it possible to keep the stress constant within 0.1% up to a strain 0.45, assuming the volume of the specimen does not change during the test. The cam profile has been solved for specimen gage lengths of 50.0, 35.0, and 25.0 mm. The static counterbalance of the loading system ensures its high sensitivity, which, together with the minimizing of frictional forces, offers the possibility for the tensile stress to be accurately defined. Erratum to this paper appears in 4(4)
Instruments for Inspection of Coatings
Authors: Berger DM , Mroz SE
Published: May 2009

The long expected life of a coating system depends on surface preparation, application of the coating, quality of the material, and good inspection practices. ASTM Committees D01.43 Coatings for Power Generation Facilities and ASTM D01.46 Industrial Protective Painting are concerned with inspection. Visual standards and instruments are used to inspect various nuclear grade coatings. Magnetic and eddy current gages are used for measuring film thickness. Holiday detectors and the Elecometer adhesion tester are a part of coating inspection.
Past, Present, and Potential Developments of Sulfate-Resisting Concretes
Authors: Kalousek GL , Porter LC , Harboe EM
Published: May 2009

The relations between computed or measured C3A contents and sulfate deterioration of concrete and the modifying effects of C4AF on these relations are discussed. The poor performances of some high quality sulfate-resisting mortars and concretes and the anomalous effects of porosities of cement pastes are considered. Research indicates that the life expectancy of pozzolan concretes relates more to the kind of pozzolan than to limitations on amounts of C3A and C4AF of Types II and V cements. Future specifications should consider interrelations of pozzolan quality, W/C ratio, and rigorously defined porosity as primary factors in sulfate attack on concretes. Results showed that Type II and Type V cements used with the same pozzolans were equally effective in resisting sulfate attack. Present hypotheses on the effects of C4AF on sulfate attack or prevention of attack are not sufficiently developed for practical use.
Elevated Temperature Fatigue of Aluminum Alloy 5454 [Addendum to “Low Cycle Fatigue of Aluminum Alloys”]
Authors: Brodrick RF
Published: May 2009

Fatigue data for aluminum alloy 5454 in the annealed condition and in the half-hard and stabilized condition, at a test temperature of 300°F (149°C), are given. These data are developed from load-controlled tests and cover the cyclic life region from about 1 × 105 to 2 × 106. The data supplement previously presented data from strain-controlled tests covering the cyclic life region below 1 × 104 cycles.
Corrosion and Dezincification of Brasses in Water
Authors: Skidmore KF , Schwartzbart H
Published: May 2009

A study of the corrosion and, specifically, dezincification resistance of several commercial and proprietary red, semi-red, and yellow brasses in water is reported. The primary variables were the composition, method of manufacture, and thermomechanical history of the metal, the composition and temperature of the water, and the exposure time. Two types of tests were utilized: (1) static immersion tests of 17 days' duration in a solution specially formulated to reveal dezincification attack and (2) static immersion tests of one year's duration in a synthesized, aggressive, potable water at room and elevated temperatures. The principal findings were that sand-cast red and semi-red brasses (CDA Alloys 836, 844, and 848) exhibited excellent dezincification resistance, as did the newly developed yellow brasses. The CDA 377 forging brass had poor dezincification resistance. Lead pitting can occur in long time exposure to water on machined surfaces of cast leaded red and leaded semi-red brasses and in free cutting brass.
Uniaxial Tensile Strength of Cementitious Composites
Authors: Toutanji HA , El-Korchi T
Published: May 2009

A brief review of various methods of measuring the uniaxial tensile strength of cementitious composites is presented. The pros and cons of these methods are described. Common problems associated with the traditional uniaxial tension testing techniques exist, and these problems arise from two areas: (1) stress concentration at gripping and (2) misalignment. These testing artifacts can significantly influence the test results, producing measurements that underestimate the intrinsic strength of the material. A novel approach for testing cementitious composites in tension is described. The test uses cylindrical bar specimens 9.5 mm in diameter and 120 mm in length. The specimens are fractured in a hydraulic chamber which allows specimen self-alignment. The advantages of using the technique are minimization of misalignment and stress concentration, larger specimen volume under stress, and determination of initiation of fracture.

The tensile strength values obtained using the hydraulic tension test technique are compared to those obtained by the traditional uniaxial tension tests. The average tensile strength of bigger size specimens, such as 16 mm in diameter and 120 mm in length, was predicted using the application of Weibull theory. Furthermore, these specimens were also tested using the hydraulic tension testing technique. The data show that the predicted values obtained using the application of Weibull theory compare well with the experimental values obtained by the novel teasion testing technique.
Temperature Dependencies of Elasticity Characteristics for Tellurium-Alloyed Gallium Arsenide
Authors: Troyanskii AI , Borisenko VA
Published: May 2009

The influence of thermal loading on the elasticity characteristics of low-alloyed monocrystalline gallium arsenide has been studied by a precision ultrasonic method in the temperature range from 190 to 380 K. The deviation of the obtained temperature dependencies from some averaged curve is shown to be more appreciable in the first cycle of thermal loading than in subsequent ones.
Standardized Training through the Use of the ICAO Standardized Training Packages (STPs)
Authors: Sutherland RG
Published: May 2009

A discussion of the development of standardized training packages (STPs) for global application in aviation security is presented.
IATA and Its Cooperative Role in Aviation Security
Authors: Wall B
Published: May 2009

The functions and activities of the International Air Transport Association (IATA), the world trade organization of scheduled airlines, particularly in reference to air security, are discussed.
The Influence of Test Piece Preparation on the Compressive Strength of Unidirectional Fiber-Reinforced Plastic
Authors: Häberle JG , Matthews FL
Published: May 2009

During a wide-ranging experimental study of compression testing of unidirectional fiber-reinforced plastics (FRP), covering several materials and test methods, it became apparent that the variability of data could be reduced by adopting a rigorous and consistent approach to all phases of specimen production. Details are given of the procedures adopted, together with results from an associated parameter study.
Behavior of Wood in Transverse Compression
Authors: Pellicane PJ , Bodig J , Mrema AL
Published: May 2009

A finite element analysis program exists to evaluate the stress distribution in wood members subjected to perpendicular-to-grain (transverse) compression. In this study, the program was used to perform parameter studies to evaluate the effects of key variables on the distribution of stresses and the maximum stress concentrations in wood subjected to transverse compression. These variables included: specimen geometry (length/depth), loading geometry (loaded length/specimen length), and material properties (ratio of moduli of elasticity of the wood in the direction of loading/perpendicular to loading).

The results showed that a complex state of stress exists in members even when the load is distributed over the entire specimen surface. In particular, numerically-determined stresses nearly 3.5 times the nominal stress were found for certain combinations of input parameters. In addition, an empirically-derived equation is presented that estimates the magnitude of maximum stress concentration as a function of the three parameters investigated. The equation was developed with the use of multiple regression techniques and had a correlation coefficient of 0.958.
Back Face Strain Calibration for Crack Length Measurements
Authors: Shaw WJD , Zhao W
Published: May 2009

A new calibration of back face strain (BFS) versus crack length a was developed. The calibration incorporates crack closure effects and is based upon a least squares multiple curvilinear regression analysis using seven specimens. Fatigue crack growth took place over a range of crack length to width ratios a/W from 0.2 to 0.8. The information was obtained under constant change in stress intensity factor ΔK using compact fractures toughness specimens of 2024-T351 aluminum alloy. In addition, two segular fatigue life crack propagation test conditions were used in the analysis database. The calibration function A*(a/W) is presented in a tubular form as well as in a polynomial equation format. The physical crack length was measured on both surfaces and later, after fracture, corrections of crack length were made for both curvature and plastic zone size. No effect of ΔK and specimen thickness on the calibration behavior was found to occur. The calibration equation was checked against crack lengths during fatigue crack growth behavior of both HSLA steel and mechanically alloyed aluminum materials and was found to be accurate.
Comparison of Asphalt Contents Measured with the Nuclear Gage and Extraction Methods
Authors: Parker F , Wu Y
Published: May 2009

Asphalt content is a critical property for controlling the quality of hot mix asphalt. Currently two procedures, solvent extraction (ASTM D 2172, Test Method for Quantitative Extraction of Bitumen from Bituminous Paving Mixtures) and nuclear gage (ASTM D 4125, Test Method for Asphalt Content of Bituminous Mixtures by the Nuclear Method), are used to compare asphalt content. This paper uses field data and data from four laboratory round robin testings to compare asphalt contents measured by the two methods. Asphalt content measurements made by nuclear gages are higher, more accurate, and more precise than asphalt content measurements made by the centrifuge solvent extraction method.
The Determination of Single Edge-Notched Bend Specimen Load Line Displacement from Remotely Located Sensors in Elastic-Plastic Fracture Testing
Authors: KarisAllen KJ , Matthews JR
Published: May 2009

ASTM E 813 and E 1152 currently allow for the determination of specimen load point deflection from a remotely located sensor provided that machine compliance (determined from the loading portion of an unnotched bend bar) is removed. If the specimen sustains significant plastic brinelling at the load points, the result is a nonconservative estimate of deflection (and J) subsequent to maximum load. A procedure for the determination of machine compliance relationships for both loading and unloading conditions is presented. Unnotched bend bars of tempered SAE 4340 were tested to compare loading and unloading machine deflection relationships.
Monitoring Crack Advance Using Acoustic Emission and Combined Acoustic Emission and Potential Drop in Zr-2.5% Nb
Authors: Lin G , Skrzypek S , Li D , Eadie RL
Published: May 2009

Experithental results are reported on the application of acoustic emission (AE) and combined acoustic emission and potential drop (PD) in crack advance measurement. Acoustic emission by itself is not a quantitastive technique for measuring crack advance. Compared with the application of only PD, using both simultaneously turns out to be quite beneficial. Used to measure delayed hydride cracking velocity in Zr-2.5% Nb, combined AE and PD, together with other techniques such as fractography, produces more reliable results with higher accuracy for isothermal conditions and particularly during temperature transients. Information about the correlation between AE and PD signals has been also obtained, which improves our understanding of the processes being studied.
A New Approach to Measuring Transverse Properties of Structural Tubing by a Ring Test—Experimental Investigation
Authors: Arsène S , Bai J
Published: May 2009

The experimental investigation of a new approach to the ring test is presented in this paper. A new design of an optimized ring specimen geometry and ring testing system was used, which was described in an earlier paper. Based on the three-dimensional elastoplastic finite element modeling with contact, a procedure for determining the stress from the global force and the strain from the global displacement has been proposed. The influences of different parameters, such as yield strength, hardening rate, Young's modulus, and friction coefficient on these curves has been examined. A comparison has been made between the finite element modeling results and the ring test results on two materials. One is a model material (aluminum-silicon, an aluminum alloy reinforced by silicon particles) that has been widely investigated in our laboratory and the second is a material (Zircaloy) used in the nuclear industry.
Experimental Analysis of Bolted Joints in Wood
Authors: Patton-Mallory M , Pellicane PJ , Smith FW
Published: May 2009

Two hundred forty-three experiments were conducted on bolted wood connections having a variety of aspect ratios (length of bolt in member/bolt diameter) and end distances with loading applied in tension and compression. Load-displacement (P-Δ) curves were generated for each test from which pertinent characteristic values were derived. Important connection characteristics observed included ultimate load and displacement, 5% offset load, proportional limit, and failure mode.

Results show the effects of connection geometry and load application on the strength and stiffness of single bolt connections. Among the most important of these are that tension and compression loadings produce different P-Δ behavior and failure modes. These differences are amplified or muted depending upon connection aspect ratio. Furthermore, connection aspect ratio and end distance interact to influence P-Δ behavior and failure mode.
An Automatic Procedure for Evaluation of Young's Modulus of Metallic Materials
Authors: Bray A , Barbato G , Franceschini F , Levi R , Romano D , Zompi A
Published: May 2009

This paper concerns the automatic evaluation of Young's modulus of metallic materials. A procedure has been developed to support the experimental measurement process. A calculation scheme for an evaluation of the overall uncertainty of modulus value is presented according to ISO/IEC/OIML/BIPM guide by ISO TAG4/WG3. Some numerical experimental results are also provided.
Modeling Bolted Connections in Wood: A Three-Dimensional Finite-Element Approach
Authors: Patton-Mallory M , Smith FW , Pellicane PJ
Published: May 2009

A three-dimensional (3-D) finite-element model was developed and verified which is capable of predicting the failure mode and load-deformation (P - Δ) behavior of a single bolted connection in wood. The 3-D geometry of the model is complemented by a trilinear orthotropic constitutive model for wood and an elastic-perfectly plastic constitutive characterization of the pin (bolt). The model accounted for the nonlinear behavior found in bolted wood connections associated with wood crushing and geometric nonlinearities at the wood/metal interface. A special contact element was used at the wood/pin interface to enforce a criterion of no pin penetration (i.e., strain compatibility) through the wood member.

Experimentally obtained P-Δ curves were compared against those obtained numerically. For all geometries studied, the model proved to capture the characteristics of the experimental analyses.
Evaluation of the Fracture Toughness of the Deep-Carburized Layer
Authors: Fu Y , Gu Y , Batchelor AW
Published: May 2009

The composite nature of case-hardened materials, meaning the existence of the gradients of microstructure, toughness, and residual stresses, ensures that the fracture in the case layer is quite different from that of homogeneous materials. In this paper a new method to evaluate the fracture toughness of the deep-carburized layer is discussed. This method uses the “pop-in” phenomenon that happens when the crack propagates through the carburized layer. The results show that the “pop-in” phenomenon is caused by the gradient distribution of the fracture toughness, the microstructure, and the residual stresses in the carburized layer. The KIC-X (distance from notch) distribution curve calculated from the load and the crack length at the “pop-in” point is the basis for the evaluation of the fracture toughness.
Crack Arrest Fracture Toughness Testing of Naval Construction Steels
Authors: Burch IA , Ritter JC , Saunders DS , Underwood JH
Published: May 2009

A program was undertaken to apply the ASTM E 1221 test method to two submarine steels exhibiting high ratios of toughness to yield stress. The objective was to measure the capacities of these steels and representative shipyard welds to arrest fast running cracks. Although the method is not a measure of dynamic toughness, it was considered to be a procedure capable of comparing the crack arresting abilities of these steels.

The work has shown that it is possible to follow ASTM E 1221 and obtain valid crack arrest fracture toughness results for materials with room temperature KJc as high as 240 MPa√m and a yield stress of 690 MPa using specimens of 50-mm thickness. The process did, however, have a high level of unreliability, necessitating a large number of tests and extensive re-testing to obtain valid results. Test temperatures below −60°C were required to obtain run-arrest events, and as such could not easily be related to material qualification procedures such as explosion bulge testing or to submarine operating temperatures.
Corrections for Triaxial Tests on Undisturbed Soils
Authors: Zhu JH , Anderson SA
Published: May 2009

Triaxial shear tests on cohesive soils involve many sources of error. The membrane compliance, membrane resistance, and variations in cross-sectional area during testing are of significance in evaluating test results, especially when the test is conducted under low stress level conditions. The methods of correction to account for these three sources of error are briefly described and an overall correction procedure based on the soil behavior observed during the testing is developed. It is found from correction results that ignorance in making corrections accounting for the three above-mentioned effects will either overestimate or underestimate shear strength of the soil by as much as 30%.
Asphalt-Rubber Mixture Behavior and Design (Wet Process)
Authors: Goulias DG , Ali AH
Published: May 2009

The use of natural and synthetic rubber for improving the properties of conventional asphalt materials has been investigated since the 1960s. Due to the additional complexity in understanding, designing, and producing rubber-modified binders and mixtures, high production cost, and in some cases conflicting reports regarding their performance, the development and use of these mixtures has been limited over the years. Recently, due to the provisions of the 1991 Intermodal Surface Transportation Efficiency Act (ISTEA) on the use of tire rubber in federally funded projects, several laboratory and field studies were undertaken.

This paper describes the laboratory results of asphalt-rubber binder and mixtures characterization with materials used in New Jersay pavement projects. Specifically, the reaction curve (i.e., viscosity versus time) and the results of traditional binder tests are presented. The effects of oxidation and aging during binder and mixture preparation and laydown operations were also examined. The modified mixtures were designed according to Federal Highway Administration (FHWA) recommendations for dense-graded rubber-modified mixtures (wet process) and compared with conventional asphalt mixtures. While the overall objective of this investigation is the development of an improved mix design methodology, using the Strategic Highway Research Program (SHRP) recommendations for dynamic modulus testing, this paper presents the results from the initial evaluation of the mixtures. During this phase the possibility was considered of enhancing the traditional Marshall mix design with mixture behavior parameters since, first, a recent FHWA study concluded that the Marshall method provides saccessful designs for dense-graded rubber-modified mixtures, and, accond, many of the highway agencies are still using this method (and are expected to continue until the acquisition and full acceptance of the SHRP equipment in their routine operations). Thus, stiffness, toughness, and energy absorbed were evaluated for potential integration into the existing design methodology and are presented herein. The results from the tensile strength and resilient modulus evaluation are presented.
Stress-Strain Relationship of Common Wire Nails Under Reversed Cyclic Loading
Authors: Chui YH , Ni C
Published: May 2009

Nailed timber joints are known to play an important role in the performance of light timber frame structures under extreme loading conditions such as those caused by hurricanes and earthquakes. Numerical modeling of nailed joint response to these loading conditions requires knowledge of, among other things, the load-displacement or stress-strain property of nails under reversed cyclic load. As part of an overall program of work to validate a finite element nailed joint model, a new test method was developed and a modified constitutive material model was adopted to characterize the through-zero cyclic stress-strain behavior of nails of different diameters. Four nail diameters ranging from 2.78 to 4.08 mm were evaluated using the proposed cyclic test and the conventional monotonic tension test methods. It is noted that the proposed constitutive model provides an excellent representation of the cyclic response of the nails. A comparison with monotonic test data reveals that yield stress under cyclic loading is higher than the corresponding monotonic test response, but the ultimate strength appears unaffected. Under cyclic loading the so-called Bauschinger and strain-softening effects are clearly evident. Elastic moduli are similar for the four nails tested. However, yield stress and strain reduce with any increase in nail diameter. The area enclosed by a hysteresis loop increases with increasing nail size.