bluuebunny/crossref_metadata_2025 huggingface dataset:
Elastic Representation Surfaces of Unidirectional Graphite/Epoxy Composites
Authors: Kriz RD , Ledbetter HM
Published: December 2008

Unidirectional graphite/epoxy composites exhibit high elastic anisotropy and unusual geometrical features in their elastic-property polar diagrams. From the five-component transverse-isotropic elastic-stiffness tensor we compute and display representation surfaces for Young's modulus, torsional modulus, linear compressibility, and Poisson's ratios. Based on Christoffel-equation solutions, we describe some unusual elastic-wave-surface topological features. Musgrave considered in detail the differences between phase-velocity and group-velocity surfaces arising from high elastic anisotropy. For these composites, we find effects similar to, but more dramatic than, Musgrave's. Some new, unexpected results for graphite/epoxy include: a shearwave velocity that exceeds a longitudinal-wave velocity in the plane transverse to the fiber; a wave that changes polarization character from longitudinal to transverse as the propagation direction sweeps from the fiber axis to the perpendicular axis.
Shear Modulus of Epoxy Resin Under Compression
Authors: Hayashi T
Published: December 2008

The matrix shear modulus of a unidirectionally fiber-reinforced composite material is one of the factors affecting its compressive shear mode fracture and it depends on the compressive stress.

In order to investigate the effect of compressive stress on the shear modulus, a special form of test specimen was designed such that compressive and torsional loads could be applied simultaneously. Test specimens were molded from epoxy resin for structural use.

Under every constant compressive load, specimens were subjected to torsional moment, and the corresponding strains were measured from which shear strains were calculated. Then the shear modulus was obtained as a function of compressive stress.

It was found that the shear modulus of epoxy resin decreased with increasing compressive stress in the range beyond the proportional limit, and the order of magnitude of its reduction was found.
Determination of Steady State Creep Rates and Activation Parameters for Rock Salt
Authors: Wawersik WR
Published: December 2008

Measurements of steady state creep rates and activation parameters are described for rock salt at low temperature (T ≤ 0.4Tm; where Tm is melting temperature) and low strain rates. The determinations of steady state creep rates rely on the evaluation of upper and lower bounds associated with characteristic transients after changes in stress and temperature. First order activation analyses make use of correlations between the steady state creep rates, stress, and temperature. More rigorous activation analyses result from comparisons of creep rates right before and after temperature and stress changes. Selected experimental results are given for rock salts from two locales deformed between 40 and 160°C. Based on measured values of activation enthalpies, activation areas, correlations between steady state creep rates by means of a power law, and some temperature-induced transients, it is suggested that the low-temperature creep of rock salt is affected by large, independent contributions from glide mechanisms besides dislocation climb.
Development of a Test Series to Determine In Situ Thermomechanical and Transport Properties
Authors: Hardin EL , Voegele MD , Board MP , Pratt HR
Published: December 2008

A small number of heated block tests have been performed, with the objective of determining the usefulness of large-scale field testing in site characterization for an underground nuclear waste repository. These tests have been research oriented, involving independent control of the state of stress and temperature in a specimen of rock having a volume of 8 m3. The heated block test is a logical candidate to obtain information on repository design and licensing, particularly for validating predictive repository model performance. A description is given of the preparation, field work, and analysis that comprised the heated block tests at the Colorado School of Mines (CSM) experimental mine and G-tunnel on the Nevada test site. These demonstrations of the heated block test showed that additional refinement is possible and especially that the method was effective in gathering meaningful data not obtainable by any other means. Such data included the apparent coupling of the effects of independently controlled stress and temperature on the deformation behavior of jointed rock, and on the conductivity of a single fracture to injected water.
Measurements of Central and Peripheral Pulmonary Function to Assess Responses to Air Pollutants: An Overview
Authors: Utell MJ
Published: December 2008

An assessment of the effects of air pollutants on the respiratory system generally requires a measurement of lung function. Essentially all experimental protocols involving inhalation studies in man have assessed responses by indices of respiratory mechanics. This paper examines pulmonary function parameters utilized by clinical investigators (1) to detect bronchoconstriction induced during controlled pollutant exposures, (2) to evaluate effects of exposure, especially those involving the peripheral lung, and (3) to select participants for controlled pollutant studies. Even the most established tests of pulmonary function, the forced vital capacity in 1 s (FEV1) and airway resistance, have shortcomings. Inhalation to total lung capacity during measurements of FEV1 may alter airway tone, and changes in airway resistance may reflect large contributions from the upper airway. Recent, more sensitive tests developed to measure peripheral airway changes suffer from interpretation problems and poor reproducibility. Efforts to utilize pulmonary function data from controlled pollutant studies to develop exposure-response relationships are discussed.
Collection and Analysis of Symptom Data in Clinical Air Pollution Studies
Authors: Hackney JD , Linn WS
Published: December 2008

Symptoms represent an important dimension of people's responses to irritant air pollutants and deserve careful attention in clinical exposure studies. Scientific investigation is handicapped somewhat in that symptoms cannot be verified objectively, nor can they be quantitated rigorously like common physiological observations. Symptom evaluations in exposure studies may take the form of verbal descriptions, incidence or prevalence rates (counts of symptomatic versus asymptomatic subjects), or scores on an arbitrary ordinal scale (for example, with larger numbers representing greater degrees of severity). Our experience supports the use of written multiple-choice questionnaires with ordinal scoring. In groups of subjects large enough for meaningful statistical analyses, the questionnaire technique compares favorably with pulmonary physiological tests, in terms of its sensitivity in detecting responses to pollutant exposure. However, any given individual may show little correlation between symptoms and physiological response. Widespread standardization of symptom questionnaires has been useful in epidemiology and should by considered in clinical exposure studies.
Pulmonary Effects of Inhaled Sulfur Dioxide in Atopic Adolescent Subjects: A Review
Authors: Koenig JQ , Pierson WE
Published: December 2008

Atopic adolescent subjects with and without hypersensitive airways, as defined by responses to exercise challenge and methacholine challenge, have been studied during acute exposure to 1 ppm sulfur dioxide (SO2) and sodium chloride (NaCl) droplet aerosol. Changes in lung function following exposure were assessed by measuring total respiratory resistance, maximum flow at 50 and 75% of vital capacity, and forced expiratory volume in 1 s (FEV1). Atopic adolescent subjects with extrinsic asthma and exercise-induced bronchospasm were extremely susceptible to inhaled SO2 at the concentration used. As a group they showed a 23% decrease in FEV1 and a 67% increase in total respiratory resistance, and some had symptoms of wheezing and shortness of breath. On the other hand, atopic adolescent subjects with no signs of airway hypersensitivity were no more susceptible to inhaled SO2 than were a group of healthy adolescent subjects studied for comparison.
A Unified Approach to the Use of Human Clinical Studies: Problems with Data Aggregation
Authors: Colucci AV
Published: December 2008

In this report, the author has set forth his approach to aggregating data from diverse studies designed to assess the impact of pollutant gases on pulmonary function. In addition, several key problem areas have been highlighted by example. The author has confined himself to studies conducted on humans under controlled exposure conditions; he reasoned that initial efforts should be limited in scope because this approach necessitates selecting out of a vast number of studies those few that are considered uniformly sound enough to serve as the quantitative foundation for risk analysis and as the norm to which future results will be compared. Since the selection process must combine methods that are both objective and subjective, particularly when criteria for study exclusion are derived, valuable counsel was sought and received from colleagues who, by virtue of their training and experience, could aid in developing the assessment format.
Phosphorus-Based Anionic Surface-Active Agents and Their Role in Agrochemical Formulations
Authors: Sheridan GP
Published: December 2008

Phosphorus-based anionic surfactants prepared by reacting an alcohol or an ethoxylate with tetraphosphoric acid (TPA) or with phosphorus pentoxide (P2O5) are complex in structure, yielding differing compositions of mono- and diprotic species of alkyl phosphates. When surfactants prepared from TPA-based product and P2O5-based product are compared, it is seen that whilst the free alcohol content is essentially the same, the monoester content has been considerably increased at the expense of the “diprotic” or polyphosphate species. The properties exhibited by these surface-active agents can be directly attributed to these structural differences and are particularly emphasized in the formulation of agrochemicals. Phosphates prepared using P2O5 can be of significant advantage in the formulation of emulsifiable concentrates and suspension concentrates where the influence of the diprotic species assists emulsion stability and dispersion rheology, whereas the TPA route is preferable in circumstances involving high electrolyte conditions such as fertilizer solutions.
Seed Treatment Formulations: Development of a Protocol
Authors: Halliday CG
Published: December 2008

Since the late 1940s, and perhaps even earlier, pesticidal compositions to treat seeds prior to planting, for the control of certain fungi as well as soil insects, have been developed and manufactured. Until the late 1960s, organo-mercury compounds dominated the seed treatment field, especially in the treatment of cereals (wheat, barley, etc.). With the banning of organo-mercury compounds for seed treatment use by various governments throughout the world, a new breed of fungicidal compounds was developed for treating seed, with many of these having systemic properties. This paper describes briefly a protocol for the development of seed treatment formulations which has been used successfully by the author over the last 15 years. The protocol outlines the desirable physical and chemical properties of these types of pesticide formulations as well as laboratory storage and field tests which it is felt are required.
Evaluation of Factors Affecting Tank Mix Compatibility of Pesticide Combinations
Authors: Brenner WE , Brown LJ , Machado IE
Published: December 2008

Laboratory tank mix compatibility testing presents the challenge of predicting the ultimate physical fate of mixtures under a large variety of often poorly known field use conditions. Most procedures, as dictated by practical necessity, involve only a few test conditions, are easy to perform, and utilize common laboratory equipment. By reason of their simplicity, however, these tests may fail to adequately mimic, hold fixed, or consider many of the field variables which may influence compatibility.

Studies were conducted with two formulations of each of two pesticides to explore the effects of some of the variables generally known or perceived to affect formulation performance and physical compatibility. Fractional factorial experimental designs were conducted in stages to study the effects and interactions of water hardness, temperature, copesticide ratio, order of addition, degree of agitation, residence time of the mix in the tank, and dilution rate. For one of the formulation pairs multiple regression and analysis of variance were used to construct a model which was able to adequately predict the failure or success of experiments not yet performed. The results indicate that all these factors can affect tank mix compatibility. Complex interactions between the factors were observed. The effects and interactions of the factors appeared to vary both qualitatively and quantitatively from the other formulation pairs, indicating that the major effects and critical ranges of factors are different for different tank mixes. These results indicate the types of difficulties which can be expected to be encountered in devising simple standardized tests for tank mix compatibility.
Use of Electrostatics, Rotary Atomizers, and Vegetable Oils in Low-Volume Ground Application
Authors: Bode LE , Butler BJ , Wax LM
Published: December 2008

The viscosity of vegetable oil-pesticide mixtures is much higher than that of water-pesticide mixtures, especially at low temperatures. Flow rates of soybean oil through regular flat fan nozzles are similar to those of water, while flow rates through flooding nozzles decreased dramatically when soybean oil was sprayed. Soybean oil increased the flow rate through hollow cone nozzles as compared to water with a decreased flow as temperature increased from 25 to 40°C for the TX4 and TX6 nozzles. In field applications grass control decreased as oil was added to water as a carrier, especially at the 50% concentration. There was very little difference in weed control when using either water or soybean oil as the carrier for low-volume application of foliar herbicides. Trends indicate improved grass control and decreased broadleaved weed control when using soybean oil as a carrier as compared to water.
Low-Volume Applications of Roundup® Herbicide
Authors: Schneider RP
Published: December 2008

The growth and development of reduced tillage has been quite dramatic. In the United States, Australia/New Zealand, Canada and Europe, farming practices have changed significantly to adopt new equipment, herbicides, crop varieties and fertilizer applications. Simultaneously, a change that has dramatically affected herbicide use is low volume applications. Aerial application, low volume hydraulic nozzles, and controlled-droplet applicators are means by which low volume application can be achieved. Research conducted with reduced carrier volumes has led to the use of reduced rates of Roundup® herbicide in annual and perennial weed markets.
Dry Application of Dry Flowable Formulations
Authors: Gandrud DE , Haugen NL
Published: December 2008

Dry flowable formulations or herbicides that are intended to be applied in the water can be applied dry. Rates as low as ¼ lb/acre can be metered and distributed uniformly with a new metering system and a pneumatic distribution system.
Determination of the Liquid Holding Capacity (LHC) or Sorptivity of Agricultural Carriers
Authors: Sawyer EW , Purcell RJ
Published: December 2008

Carriers of interest and test methods for determining their ability to hold various concentrations of liquid technicals while remaining free flowing enough for handling and application are described. Discussions of property parameters pertinent to feasible impregnation cycles and adequate distribution include data on the effects of particle size distribution, heat treatment, moisture content, carrier type, rate of absorption, test temperature, and sorbate properties. Testing of both powdered and granular absorbent carriers derived from naturally occurring minerals and botanical sources are detailed. Feasible plant processing operations may not only depend on “one-step” impregnations of carriers but can involve such features as multiple impregnations with solvent removal steps or drying after each impregnation, and the test should be sufficiently flexible to cover such a possibility. Of primary importance in the in-plant processing of liquid materials on carriers to make dusts or granular pesticides is the rate of absorption, which is never instantaneous but can range from very rapid (minutes) to very slow (hours). Possible procedural variations must be featured in the testing techniques to allow for this difference in absorptive rates. The bottom line on all sorptivity tests is to supply the formulator with easy-to-obtain information telling him what he can accomplish in plant processing and to show him in advance the physical characteristics of resultant final products. Thus the aim of sorptivity testing is not only to characterize absorbents, but also to avoid surprises in processing.
The Reversing D-C Electrical Potential Method
Authors: Catlin WR , Lord DC , Prater TA , Coffin LF
Published: December 2008

An automated reversing d-c potential system capable of measuring crack growth rates in compact-type, edge-notched, and surface-defected specimens under a wide variety of environmental conditions is described. Measurements can be made with ease during cyclic or static loading conditions. The unique characteristics of the system software, which give the operator a wide choice of test routines, including constant load range, constant stress-intensity range, and programmed load range or programmed stress-intensity range, are discussed. Detailed procedures are then given for conducting a “controlled K” cyclic test on a surface-defected specimen.

The system has outstanding stability and sensitivity. The high frequency of measurement permits averaging of many readings within a given cycle to obtain a single data point or to detail a given cycle. Techniques for averaging data to enhance the resolution of growth rate measurements are discussed.

Finally, results from several tests are described to demonstrate the versatility of the system in making measurements on different specimen geometries over a wide range of testing conditions.
Automated Test Methods for Fatigue Crack Growth and Fracture Toughness Tests on Irradiated Stainless Steels at High Temperature
Authors: Tjoa GL , van den Broek FP , Schaap BAJ
Published: December 2008

An automated system for fatigue crack growth and fracture toughness measurements has been developed for irradiated stainless steels tested at temperatures up to 925 K. The system, including a microcomputer, is based on the d-c potential-drop technique for crack extension measurements. Specimens of the compact-tension type are used for the experiments. A description is given of the potential-drop method and the automated data acquisition system. The method of collecting N-a data pairs is given as well as the calculation and analysis of the fatigue crack growth rate (da/dN) and stress-intensity factor (ΔK). The measurement of load, deflection, and crack extension data to determine the J-versus-Δa curves is also discussed.

Calculations and interpretations of the results are in good agreement with the ASTM standards.

The system for crack growth experiments has proven to be very reliable, with a high resolution and accuracy.

In practice, good experience has been gained using the system for testing irradiated specimens under remote handling conditions.
An Automated Fatigue Crack Growth Rate Test System
Authors: Cheng Y-W , Read DT
Published: December 2008

An automated fatigue crack growth rate (FCGR) test system has been developed that can be used for tests of constant-load-amplitude FCGR above 10−8 m/cycle [ASTM Test Method for Constant-Load-Amplitude Fatigue Crack Growth Rates Above 10−8 m/Cycle (E 647-83)] at normal (∼ 10 Hz) or low (∼ 0.1 Hz) cyclic frequencies and for tests of near-threshold and variable-load-amplitude FCGR. The test system consists of a minicomputer, a programmable arbitrary waveform generator, a servo-hydraulic test frame, and a programmable digital oscilloscope. The crack length is measured using the compliance technique; the FCGR and the stress-intensity factor range are calculated and plotted automatically during the test.
An Automated Method of Computer-Controlled Low-Cycle Fatigue Crack Growth Testing Using the Elastic-Plastic Parameter Cyclic J
Authors: Joyce JA , Sutton GE
Published: December 2008

The application of J-integral methods to fatigue crack growth testing was first presented by Dowling and Begley [1]. They demonstrated that under certain conditions the J-integral range (ΔJ) applied to a cracked body correlates well with the measured crack growth per cycle in tests performed in the elastic-plastic regime. This paper presents an automated test system for computer-controlled low-cycle fatigue crack growth evaluation of ductile materials using cyclic-J, and details the procedure for this technique. The system consists of a hydraulic test machine, a minicomputer, and a microcomputer. The test machine is controlled in either clipgage or stroke mode with the control signal of the minicomputer channeled through a digital-to-analog converter. The microcomputer is dedicated to compliance calculation. Analysis of crack length, closure load, and applied ΔJ is performed each cycle and the control signal is adjusted to achieve the desired J-range. Crack growth results are periodically stored on disk along with load-crack opening displacement data for the cycle.

This automated system has been utilized for rising J-range, J-range shedding, and constant J-range tests using compact tension specimens of two high-strength structural steels. Results from these tests show agreement with the linear extrapolation of crack growth data obtained under linear-elastic conditions, and demonstrate the promise of such an approach for low-cycle fatigue crack growth characterization.
Error Analysis of Measuring Thermal Conductivity by Circular and One Side Heat Flow Type Guarded Hot Plate Apparatus
Authors: Eguchi K
Published: December 2008

This paper deals with the theoretical analysis on total errors which occur upon measuring the thermal conductivity of a circular specimen using a one side heat flow type guarded hot plate.

Introducing three input parameters, that is, (a) temperature of ambient air, (b) that of guard ring, and (c) that of guard plate, which are normalized by letting the temperature of a hot plate be a unit and that of the cooling plate be zero, the theoretical solution of the total errors was derived. The errors were classified into the ones caused by the three parameters, and they were also classified according to the heat flow paths.

Heat exchange at the edges of the specimen and insulation between hot plate and guard plate was treated as the surface heat transfer including edge insulation.

The total errors were expressed with the following seven normalized parameters, that is, (a) ratio of the radius of the hot plate to that of the guard ring, (b) ratio of the thickness of the specimen to the radius of the guard ring, (c) ratio of the thickness of the insulation between the hot plate and the guard plate to the radius of the guard ring, (d) ratio of the thermal conductivity of the insulation to that of the specimen, (e) ratio of the equivalent edge insulation thickness to the radius of the guard ring, (f) ratio of the direct heat flow across the gap to the heat flow out of the hot plate into the specimen which is obtained assuming one-directional heat flow, and (g) ratio of the direct heat flow through the thermal bridges between the hot plate and the guard plate to the heat flow out of the hot plate into the insulation which is obtained assuming one-directional heat flow.

In this paper, each of (f) and (g) is considered to be determined by the analytical solution using experimental data.
Summary of Error Analysis for the National Bureau of Standards 1016-mm Guarded Hot Plate and Considerations Regarding Systematic Error for the Heat Flow Meter Apparatus
Authors: Rennex B
Published: December 2008

A summary is given of the error analysis of the National Bureau of Standards (NBS) 1016-mm guarded hot plate (GHP) apparatus, with emphasis given to new ideas or techniques. The report discusses the following items: a brief introduction to the principle of measurement, a rationale for the method of summing of uncertainties, a list of individual uncertainties, a description of the innovative plate temperature control method, and a derivation of the error due to systematic uncertainty for the heat flow meter apparatus.
Present and Future Research on Guarded Hot Plate and Heat Flow Meter Apparatus
Authors: De Ponte F
Published: December 2008

The paper discusses some problems related to the guarded hot plate (GHP) and heat flow meter (HFM) apparatus that justify today research efforts and future research programs. For the GHP these include the problem of imbalance detection and its correlation with the metering area definition, the problem of gap width, and the problem of apparatus speed. Also discussed are the specimen-related issues involved in measurements on rigid, highly conductive materials and mass transfer within the specimen during tests.

For the HFM apparatus the different configurations are surveyed, and the effect of the HFM temperature uniformity and its possible correlation with the HFM thermopile layout are discussed.

In conclusion a concise account is given of the activity within the International Organization for Standardization's Technical Committee 163 on Thermal Insulation in its development of international documents for the two test methods.
Development of a Large Area Heat Flow Meter
Authors: Miyake Y , Eguchi K
Published: December 2008

A large area heat flow meter (HFM) is required to measure heat flow from whole area of building walls. Therefore, the cost of the HFM must be as low as possible.

Under such background we developed a large area HFM by means of photoetching and electroplating techniques. The new large area HFM can be also used as a small area HFM by cutting it into small units. Further, we developed a new calibration method which enabled us to calibrate HFM, by both absolute and relative methods at the same time with a single apparatus due to capability of cross checking. The difference of the calibrated values by both methods was not greater than ±1%. For practical use of a large area HFM, calibration of several HFMs must be carried out at the same time; we also described the method in this paper.
Development of a Company Wide Heat Flow Meter Calibration Program Based on the National Bureau of Standards Certified Transfer Specimens
Authors: Pelanne CM
Published: December 2008

The development of a company-wide heat flow meter calibration program based on the National Bureau of Standards Certified Transfer Specimens is discussed. A description of the procedure followed in order to ensure accurate measurements of thermal insulation in conformance with the Federal Trade Commission's requirements is given. The procedure ensures the maintenance of the equipment calibration for all testing locations by providing each with a set of secondary reference specimens. To stress the importance of the program, the reference specimens and the maintenance of the equipment calibration, a Certificate of Calibration for each specimen and a set of instructions was provided to each test location.
Surface Temperature Sensor Calibration: In Situ Technique
Authors: Schumann SP
Published: December 2008

The surface temperature dectors on a guarded hot plate can be calibrated in place using differential thermopiles. A ten-junction Type T thermopile was used to calibrate a 1.22-m (4-ft) guarded hot plate using water triple point cells as the reference temperature. The stability and precision of these thermopiles, over a year's span, was on the order of 20 to 30 millidegrees.
Heavy Duty Membrane for the Reduction of Reflective Cracking in Bituminous Concrete Overlays
Authors: Knight NE , Hoffman GL
Published: December 2008

The prevalence of reflective cracking in asphaltic concrete overlays is a major factor contributing to the premature failure in the pavement system. This reflective cracking is caused by cyclic stresses induced in the overlay by movements in the underlying pavement. Recent work done with heavy duty membranes has shown that they may be useful in retarding this reflective crack formation. Seven different types of heavy duty membranes were placed over portland cement concrete pavement joints at a site in Pennsylvania before the roadway was overlayed with asphaltic concrete. Control sections, without any membranes, were also built into the project for comparison purposes. This work will evaluate the ability of these membranes to reduce the occurrence of reflective cracking over transverse and longitudinal joints and to function as a water stop once cracking has occurred.
Modeling of Heat Flux Distortion Around Heat Flux Sensors
Authors: Apthorp DM , Bligh TP
Published: December 2008

The effect of a heat flux sensor on the heat transfer in the material surrounding the sensor has been studied in detail, and a steady-state finite difference computer model has been written to predict the ratio of the heat flux through the sensor to the undisturbed flux in the material surrounding the sensor, qs/qm, as a function of the ratio of the thermal conductivity of the sensor to that of the surrounding material, , as a function of the ratio of the thermal conductivity of the sensor to that of the surrounding material, ks/km, and the geometry of the situation. The results of the program show that , and the geometry of the situation. The results of the program show that qs/qm is a strong function of is a strong function of ks/km, varying from 0.37 to 1.31 as , varying from 0.37 to 1.31 as ks/km varies from 0.1 (concrete) to 10.0 (polystyrene) for a typical sensor in the center of surroundings 25.4 mm thick.
Calibration of Heat Flux Transducers
Authors: Orlandi RD , Derderian GD , Shu LS , Siadat B
Published: December 2008

Calibration methods are presented in this paper to convert the response of heat flux transducers (HFTs) to heat flux for the analysis of in-place thermal performance of building envelopes. In general, the heat flow through any boundary of a building envelope can be measured, provided HFTs are properly calibrated. There are at least two measurement alternatives, depending on the placement of HFTs on building envelope subsystems such as walls or roof decks. In one alternative (the embedment technique) HFTs are embedded within the subsystem. In this situation, the proper calibration can be carried out in the laboratory with the HFT embedded in the same construction material. In the other alternative (the attachment technique), HFTs are attached externally, for example, to the inside surface of the subsystem. Thus, the technique is nondestructive. HFTs used in this manner are exposed to the specific building enclosure environment. Therefore, their response is affected by the prevailing convective and radiative conditions, HFT/subsystem surface interaction, subsystem geometry, and, to a lesser extent, subsystem surface temperature. The purpose of this paper is to describe recommended HFT calibration methodologies for the two HFT application techniques and to present some calibration data. The methodologies take into account the important factors that are essential for a complete description of the HFT responses.
Engineering Application of Heat Flux Sensors in Buildings—Technical Note
Authors: Isaacs N
Published: December 2008

Since 1978, new houses in New Zealand have had to achieve minimum levels of thermal insulation. A large field survey was carried out during the winter of 1983. This paper outlines the basis of the survey, the equipment used, and the measurement issues raised by the use of heat flux sensors. The results from a pilot study of 25 houses are discussed in terms of the activities that affect measurements. A comparison of calculated and “measured” R-values for known walls indicates a measurement “calibration” of within 10% for the equipment and analysis.
Construction and Performance of In Situ Heat Flux Transducers
Authors: Hauser RL
Published: December 2008

Heat flux transducers have been used for the past 30 years to measure heat generation and transmission. The transducers have been made using thermopile principles with multiple junctions on opposite sides of an insulating core. Junctions have been made from welded ribbons with selective notching and folding, metallized foils, printed circuit with dissimilar junctions, and constantan wire plated with copper or silver. The overall electrical and thermal efficiency of the plated system can be in the range of 80%.

The characteristics of commercial heat flux transducers are described, ranging from very small to very large, rigid to flexible, and low to high sensitivities.

ASTM has two task groups actively developing standard practices for the use of heat flux transducers on pipelines and on buildings; both groups have had multiple ballots of initial drafts and will be ready for subcommittee ballot in the near future.

Flexible belt-type heat flux transducers have been used by the author for measuring insulation performance on steam lines. Good information was obtained showing areas of superior insulation performance and areas of deficiency or inadequacy.
Use of the Indentation Size Effect on Microhardness for Materials Characterization
Authors: Sargent PM
Published: December 2008

This paper describes several different physicochemical mechanisms that produce an indentation size effect on microhardness. The mechanisms are illustrated with reference to published data. A simple quantitative model for surface layer effects is presented, and its relevance to chemomechanical effects on ceramics is discussed.

A well-behaved empirical function describing some indentation size effects is introduced, and its advantages are discussed. It is used in a new method of graphically presenting microhardness data which is presented here for the first time. This “error-ellipsoid” diagram not only is visually compact and statistically rigorous but is based on a new physically meaningful parameter, the “10-μm hardness.”
Applicatins of Microindentation Methods in Tribology Research
Authors: Blau PJ
Published: December 2008

Microindentation techniques and tribology research have traditionally been closely linked. Three aspects of their historical relationship are discussed: (1) the use of microindentations and scratches as indicators of small amounts of wear, (2) the characterization of candidate metal and alloy microstructures for wear applications, and (3) studies of microstructures that have been altered by various wear processes. Proper application of microindentation techniques can provide information beyond simply obtaining microindentation hardness numbers. For example, one can estimate mild wear losses, crystallographic texturing due to sliding, work hardening, and fine structure sizes below eroded surfaces, strength of transfer patches on severely worn surfaces, and the variation in contact conditions across a single wear scar. Many of these areas need to be explored in more extensive quantitative ways before the full power of microindentation methods in tribology can be utilized effectively. The author reviews several published studies as well as his recent work to illustrate future research opportunities.
Quality Assurance of Polymeric Materials and Products—The Underwriters Laboratories Safety Performance Viewpoint
Authors: Bratvold H , Miller RW
Published: December 2008

Plastic materials are used in a variety of applications in devices and appliances each requiring different type materials and levels of performance. The first step in maintaining acceptable levels of product safety performance is an evaluation of the applications or uses of component materials, including polymerics. Such evaluations must include (1) a determination of the functional use of the plastic part (critical versus non-critical properties), (2) inputing manufacturing considerations, (3) establishing a performance-oriented test program, (4) preparation of comprehensive reports of test results for use in finished product compatability reviews, and (5) establishing a cost optimized follow-up program for assurance that the same component materials are used in continuing finished product production.

This paper examines the Underwriters Laboratories (UL) system of “quality assurance” for maintaining required levels of product performance. In particular, it discusses the follow-up program for polymeric materials from the manufacturer's point of view on basic ingredient and end-product.
Using Rheological Measurements for Quality Assurance
Authors: Driscoll SB
Published: December 2008

Recently, members of the ASTM Subcommittee D20.10 on Mechanical Properties have authored ASTM Definition and Description of Terms Relating to The Dynamic Mechanical Properties of Plastics (D 4092) for identifying or characterizing the important rheological properties of plastics materials and composite systems. ASTM Dynamic Mechanical Properties of Plastics (D 4065), which is being developed currently, addresses the specific procedures that are to be used in measuring these important viscoelastic properties. The study of rheology is of special interest to scientists and engineers since it identifies important macromolecular characteristics that affect the functional properties of a fabricated part, such as an injection molded steering wheel, an iron oxide coating on a magnetic recording tape, or a high strength epoxy/graphite helicopter rotor blade. In every case the quality of the incoming material, the effect of processing, and the quality of the final functional part are equally important. ASTM D 4065 and D 4092 address these needs and provide meaningful information for establishing and monitoring quality control/assurance procedures.

The review of the major features of ASTM D 4065 and selected case studies will illustrate how rheological measurements have been used in quality control/quality assurance (QC/QA) programs. Results for thermoplastics and thermosetting resins are presented, including typical additives. Dynamic mechanical properties are provided as functions of frequency (dynamic oscillation), strain, temperature, and time. Additionally, thermosetting prepregs shall be studied for the effect of cure mode, rate of heating, and post-cure thermal treatments.

The importance of ASTM D 4065 and D 4092 definitions are emphasized in the discussions.
Electropolishing Stainless Steel Implants
Authors: Irving CC
Published: December 2008

Virtually every manufacturer of AISI Type 316L stainless steel surgical implants uses electropolishing as a surface finishing procedure, but little research has been devoted to the basic chemistry, techniques, and possible benefits of the process. The electrochemical reactions that take place in the electropolishing cell are discussed, as well as the physical techniques used to electropolish stainless steel. Data on the corrosion resistance of electropolished stainless steel is compared to conventional passivation treatments.
In Vitro Studies of Aneurysm Clip Materials
Authors: Kossowsky R , Kossovsky N , Dujovny M
Published: December 2008

Seven surgical aneurysm clips, representing six stainless steels and one cobalt-based alloy, were subjected to a complete metallurgical characterization. The studies involved microstructural analysis, hardness measurements, X-ray diffraction analysis, and measurements of the galvanic passivation and resistance to pitting corrosion. Furthermore, one type of clip was subjected to a rigorous failure analysis. The results will be presented in terms of a comparative evaluation. The clinical significance of in vitro galvanic corrosion measurements will be supported by the discussion of the reasons for several failures of one type of aneurysm clip.
Biocompatibility and an Enhanced Acute Inflammatory Phase Model
Authors: Marchant RE , Sugie T , Hiltner A , Anderson JM
Published: December 2008

The evaluation of the biocompatibility of biomaterials centers on appreciating the events that occur at the tissue/implant interface. In determining the biocompatibility of biomaterials, both the host response and the material response to the host must be elucidated. The in vivo biocompatibility of candidate biomaterials may be investigated using the cage implant system. The cage implant system is presented, which allows the quantitative determination of the dynamic nature of cell function at the implant site. Results from the quantitative determination of cells and products of cell activation over the implantation period can be subjected to statistical analysis methods. In addition, studies utilizing a chemotactic tripeptide have been carried out to provide an enhanced or accelerated acute inflammatory phase model. These studies are important as they provide an in vivo situation where the effect of cells on implanted materials and the effect of biomaterials on the cellular components of the inflammatory response may be investigated.
Biodegradable Fracture Fixation Plates for Use in Maxillofacial Surgery
Authors: Casper RA , Dunn RL , Cowsar DR
Published: December 2008

Partially biodegradable composites were prepared from a biodegradable polyester, reinforced with carbon or ceramic fibers, and evaluated for their potential use in fixing mandibular fractures resulting from maxillofacial injuries. The composites, made using a lamination technique, were found to possess the strength and rigidity of bone. Their incubation in phosphate-buffered saline at 37°C resulted in the gradual reduction of both flexural strength and flexural modulus of the samples. Reductions in strength and rigidity were paralleled by commensurate reductions in the viscosity of the matrix resin. Evaluation of the model system demonstrated the potential for improved management of fracture wounds using biodegradable materials.
Tricalcium Phosphate Biodegradable Ceramic
Authors: Lemons JE
Published: December 2008

Particulate and porous scaffolds of tricalcium phosphate ceramic (TCP) have been evaluated in laboratory, laboratory animal, and human investigations. Selected applications of the particulate biodegradable ceramic have shown favorable results, especially when used with autogeneous bone. However, long-term studies of large porous scaffolds need to be expanded prior to routine human applications. Continued research on biodegradation characteristics are recommended.
Loosening of Well-Cemented Total-Hip Femoral Prosthesis Due to Creep of the Cement
Authors: Ebramzadeh E , Mina-Araghi M , Clarke IC , Ashford R
Published: December 2008

A review of previous publications on the mechanical complications of cemented total-hip prosthesis femoral component indicates several failure mechanisms. However, the biomechanical significance of the various reported radiographic phenomena has not been clearly assessed with static testing or with computer models.

A new technique was developed to directly measure internal cement strains in a simulated proximal femur with cemented femoral total-hip prostheses. Static experimental testing of a Delrin plastic-bone-analog with a cemented metallic femoral prosthesis indicated highest cement strains in the proximal-medial aspect of the cement sheath, which correlated with highest cement stresses in the same location in a corresponding finite-element analysis computer model. The most noticeable observation from the cyclic testing was the 73% decrease of cement strains in the proximal-medial region after 4.1 million cycles. This time-dependent behavior, that is, creep, may have significance in the failure mechanisms of cemented femoral total-hip replacement components and should be considered in future static or cyclic experimental testing and computer modeling of such prosthetic components.
Performance Standards: Flexible Tool or Straight Jacket?
Authors: Mayor MB
Published: December 2008

Standards documents can be written in several ways. The distinction between design standards and performance standards is examined here, in the special context of surgical materials and devices. The work of writing performance standards is significantly different, and that difference will affect the work of the task forces and committees of ASTM Committee F-4 on Medical and Surgical Materials and Devices. If the performance documents produced by Committee F-4 are well crafted, their usefulness will extend beyond the limits of the American Society for Testing and Materials to service in many different contents.
Water Quality Criteria: Protection of Use Perspective
Authors: Gostomski FE
Published: December 2008

A water quality standard is a rule or law comprised of the use or uses to be made of a water body or segment and the water quality criteria necessary to protect that use or uses. States have primary responsibility for establishing appropriate uses of water bodies through a periodic review process involving consultation with the U.S. Environmental Protection Agency (EPA) and public hearings, which must occur at least once every three years. Where designated uses do not include those specified in the goals of the Clean Water Act (that is, fishable/swimmable), the state is required to conduct a use attainability analysis. The EPA has provided guidance for doing such an analysis.

Criteria are elements of state water quality standards expressed as constituent concentrations or levels, or narrative statements, that represent a quality of water that supports a particular use. When criteria are properly selected and met, it is presumed that water quality will protect the designated use. The EPA is recommending that states develop site-specific criteria to reflect local conditions and has provided guidance for doing so.
Research Needs in Validating and Determining the Predictability of Laboratory Data to the Field
Authors: Boyle TP
Published: December 2008

Three areas of research needs are identified in translating laboratory data to the field. They are (1) an assessment of the efficiency of existing environmental fate mathematical and physical models to simulate field conditions, (2) an evaluation of the utility of single species laboratory toxicity tests to accurately assess environmental effects of contaminants, and (3) an assessment of the relative sensitivities of ecological functional processes to stress. Ideas on how to address these research needs are presented.
Acclimation as a Factor Influencing Metal Criteria
Authors: Chapman GA
Published: December 2008

Laboratory research, primarily with salmonid fish, has demonstrated that metal acclimation can increase metal tolerance. Although slight decreases in tolerance have been reported following acclimation, reports of approximate doublings in tolerance predominate. The magnitude of increased tolerance may be metal-specific, and available data suggest the magnitude of acquired tolerance follows the series: Zinc > Copper > Cadmium > Chromium. Tolerance appears to change within a week of major changes in acclimation concentration.

The significance of acclimation-induced tolerance may be important to the survival of organisms in metal-contaminated environments, but the magnitude of the tolerance change is probably within the range of many other factors influencing the accuracy of criteria. For example, the use of mean concentrations to express cycling exposure may underestimate chronic toxicity by a factor of two. Metal speciation/complexation is probably much more important to criteria accuracy than acclimation. Another important aspect of criteria evaluation is the relative resolution of laboratory tests and field monitoring. The problem of detecting biological effects following criteria violations is discussed.