bluuebunny/crossref_metadata_2025 huggingface dataset:
Methods to Include Beer's Law Nonlinearities in Quantitative Spectral Analysis
Authors: Haaland DM
Published: December 2008

Multivariate least-squares methods have been recently applied to the quantitative infrared analysis of multicomponent samples. Many deviations from Beer's law can be approximated in linear least-squares analyses by using a calibration set which consists of spectra of known mixtures and by adding a nonzero intercept to Beer's law. More recently, methods which specifically include nonlinear terms in the relationship between concentration and absorbance have been applied to samples whose spectra exhibit Beer's law deviations. Using these methods, reductions in relative errors have been achieved for several nonlinear systems compared to the results of least-squares methods which include only the linear terms. An alternate method to improve the quantitative accuracy in the presence of Beer's law deviations involves using full-spectrum residuals. Since the multivariate least-squares analysis generates estimated pure-component spectra from a calibration set of known mixture spectra, residual spectra can be generated by subtracting the appropriate amounts of the estimated spectra from the known mixture spectra. The residual spectra, which represent the nonlinearities from Beer's law that are not accurately approximated in the multivariate least-squares analysis, are then used as additional terms to improve the least-squares fit of the unknown sample spectrum. Empirically this method has been also found to improve relative errors. These methods have been applied to two systems which exhibit nonlinear Beer's law behavior, that is, binary mixtures of esters and low-resolution gas-phase spectra of nitrous oxide (N2O) in nitrogen (N2). Demonstration of the methods and a comparison of the accuracies of the different techniques are made for these two systems.
Quantitative Fourier Transform Infrared Methods for Real Complex Samples
Authors: Crocombe RA , Olson ML , Hill SL
Published: December 2008

Quantitative analysis for one-component systems (for example, additives in polymers, dilute solutions) is well understood, and the mathematical methods needed are comparatively simple. In recent years, software for multicomponent analysis has been made available for Fourier transform infrared (FT-IR) instruments, and two methods are commonly employed, termed K-matrix and P-matrix. Although the mathematical techniques involved have been described, their practical application is less well documented, and there are a number of pitfalls for the unwary analyst. This paper describes some of those pitfalls, and methods for avoiding them. Of great concern is the common occurrence of calibration using carefully prepared standards, followed by the analysis of real samples that contain impurities. This can have disastrous consequences no matter how good the calibration is. The range of concentrations that a multicomponent analysis actually spans, in reality, can be far less than the analyst may think at first sight. Some examples of applications of multicomponent infrared analysis are given, including extensions to the use of newer techniques such as diffuse reflectance, photoacoustic spectroscopy and microscopy.
Application of Target Factor Analysis to Quantitative Absorption Spectroscopy
Authors: Malinowski ER
Published: December 2008

Factor analysis is a mathematical tool for solving multidimensional problems, having great potential in absorption spectroscopy. It can be used for both qualitative and quantitative analysis of mixtures. Abstract factor analysis reveals the number of absorbing components in a mixture, calculates the real error in the measurements, and improves the data. The method can be used to compress libraries of spectroscopic data into its smallest dimensions without loss of information. Target factor analysis allows the analyst to verify the presence or absence of suspected components. Spectra of unstable intermediates can be isolated. Various examples are discussed.
The Anterior Cruciate Ligament Injury in Skiers
Authors: Figueras JM , Escalas F , Vidal A , Morgenstern R , Buló JM , Merino JA , Espadaler-Gamisans JM
Published: December 2008

This study evaluates 23 arthroscopic confirmed cases of anterior cruciate ligament rupture observed in 22 skiers. There were nine cases of isolated rupture and 14 combined with meniscus lesions. Sixty-four percent of the patients were ski racers, and 50% of the lesions occurred in skiers aged from 14 to 20 years. The injury always happened with the use of high legged boots and safety bindings, which only released with mechanisms of rotation and flexion. A backward fall or the effort to avoid it was the most frequent cause of the injury. In 10 cases, the injury occurred without the skier's fall when in a backward position, he tried to recover his balance. In this dynamic situation, an imbalance between the simultaneous contraction of the hamstrings and the quadriceps may cause a force greater than the ligament resistance. The resultant rupture can produce a forward displacement of the tibia causing compression of the posterior third of the meniscus. The use of multidirectional safety bindings or those with release when the skier falls backwards could contribute to the prevention of anterior cruciate ligament injuries.
Considerations on Mechanical Properties of Skis
Authors: Sakata T
Published: December 2008

Since 1975, the Japanese magazine, SKIER, and its technical staff have been endeavoring to measure the mechanical properties and shape of skis sold in the market. For over eleven years they measured 763 pairs of skis manufactured in various countries. In this paper the outline of the “SKI TEST” is introduced, and it shows how the typical mechanical properties of the ski have changed during these eleven years. From the results, the following two interesting facts can be postulated: (1) the torsional rigidities are not critical for skiing performance and (2) on the contrary, the flexural rigidities are so important that the flexural rigidities must be kept within tolerance.
The Force Interplay Between the Foot, Binding, and Ski in Cross-Country Skiing
Authors: Ekström H
Published: December 2008

The frequency of skiing injuries that occur during cross-country skiing is increasing, depending on new ski equipment, skiing style, and so forth. Comparative investigations of the breaking strengths for skis made of wood and fiberglass and different types of cross-country bindings and boots have been tested and compared against fracture strength data of the tibia and the knee. A combination of bending- and torsion-fracturemoment from the whole man-equipment system indicates a need for cross-country ski bindings with release functions for the future.
Comparative Laboratory Tests of Release Bindings for Children and Young Skiers with Special Reference to the Influence of Boot Material and Boot Sole Length
Authors: Gundersen TM
Published: December 2008

Comparative tests of release bindings for children and junior skiers marketed by the five major manufacturers were conducted at the TÜV winter sports laboratory in Munich, West Germany, during 1983 and 1984. The results underline the bindings' dependence of boot sole materials for proper function. Major differences in release functions were also demonstrated between the different designs. Some bindings have an unreliable basic scale of adjustment. Combined loads also lead to sharply rising release values. A design with unsatisfying performance given a small child's boot may function considerably better with the larger boot of a junior. Realities of life, like snow buildup under boots and dirty boot-binding interfaces, easily lead most of the present bindings to fail.
Laboratory Test Methods for Children's Release Bindings with Special Reference to the Inadequacies of the Present Industry Norms and the Knowledge of Injury Thresholds
Authors: Gundersen TM
Published: December 2008

Assessing release functions of children's alpine ski bindings is rendered difficult by several factors. Some of these difficulties stem from the imperfections of the presently adopted industry norms. Although the present German Industrial Standard (DIN) Winter Sports Equipment—Release Binding for Alpine Downhill Skiing for Children (DIN 7881 3-5) should certainly be recognized as being far better than no norm at all, it does leave much to be desired. The International Workshop on Skiing Safety (IAS) specification 100 would, if implemented, probably call for new designs in the realm of children's equipment. Aside from this, release functions as presently defined are all too easily inhibited by maladjustments. The present situation in Scandinavia, where surveys of children's gear show toe lug adjustment to be seriously faulty as a rule of thumb, certainly calls for some kind of remedy. The most basic research problems, however, are equally unsolved. Knowledge of injury thresholds and modes for children is lacking. We do not have the evidence on which to base a reviewed setting recommendation, not to mention a guideline for release modes.
Test Devices for Ski Bindings Sold in Sports Shops: State of the Art and Future Development
Authors: Nagel A , Mösch S
Published: December 2008

In the course of the last 15 years it has been possible to reduce the number of typical skiing injuries by means of consequent research, improvement of the skiing equipment, training of the personnel in sport shops, and information transmitted to the skiers.

Based on so-called “Lipe” numbers, a measure of unit adjustment tables with setting values for ski bindings were developed. In Germany this system is specified in the German Industrial Standard Release Bindings for Alpine Downhill Skiing; Adjustment Scale for Release Values (DIN 7881, Part 5). To set ski bindings according to these setting values, personnel of sport shops are under obligation to control the release forces or torques with a test device. Specifications for test devices are laid down in DIN Test Devices for the Adjustment of the Functional Unit Ski/Binding/Brake/Boot (32 921). Different measuring principles with certain advantages and disadvantages exist and both force-measuring and torque-measuring devices are in use. Desirable is a torque-measuring device that is simple to handle. Modern test devices register all input and calculated data as well as release values measured and give an output on a printer. Test devices are essential for detection and correction of wrong adjustment and functional disturbances of bindings. Therefore exact binding adjustments in sport shops without test devices are inconceivable in the near future.
A Small, Low Power Microcomputer-Based Controller for Snow Ski Bindings
Authors: Halsted L , Hull M
Published: December 2008

This paper describes the design and field evaluation of a microcomputer-based ski binding controller built around the Hitachi HD 63P01M1 CMOS microcomputer. Included in the controller are signal conditioning electronics intended to interface with a six load component strain gage dynamometer that measures the loading between the boot and the ski. The controller processes digitized dynamometer signals in order to determine when the boot should be released from the ski. If release is warranted, then the controller generates a release command signal. The controller is powered by a rechargeable battery pack, with a single charge sufficient for an entire day of skiing. In order to conserve battery power, the dynamometer bridges are excited by pulses. The controller also features a first-in first-out buffer memory, which stores about 3.5 s of dynamometer data. The dynamometer data can then be transmitted to an auxilliary tape recorder if desired. The tape recorder is not carried on the ski, however. Packaged in a watertight aluminum housing, the controller is mounted on the ski behind the boot.

The new binding system has been field tested by two test subjects. The instrumentation system both controlled binding release and stored segments of boot loading data. The release control algorithm used in the tests compared measured axial and fore/aft bending moments to constant threshold values. Segments of loading data are presented for one test subject in two test runs distinguished by unstaged falls.
Current Trends in Ski Injuries and Their Relationship to Recent Changes in Ski Equipment
Authors: Kuriyama S , Fujimaki E
Published: December 2008

In the past 28 years (from Dec. 1956 to April 1984), we have examined 47 165 patients with ski injuries in our ski injury clinic at the Ishiuchi ski area, Japan. Of these ski injuries, 70% were to males, 30% were to females, and classifying by age, 68.9% of the patients were in their thirties. The overall injury rate and injured persons are decreasing year by year. The most frequent injuries were knee sprains (19.6%), ankle sprains (19.3%), ankle fractures (12.8%), lower leg fractures (10.4%), and lacerations to the head and face (8.8%). These ski injuries were closely connected to developments in ski equipment being used such as safety bindings, ski boots, safety straps, and ski brakes. And, the overall injury rate is increasing year by year. Viewing from the changing of the relative percentage of total number of injuries per year, ankle sprains and ankle fractures have been decreasing, nevertheless knee sprains, fractured lower legs, and lacerations to the head and face have been increasing relatively.
Carpometacarpal Dislocations of the Thumb in Skiing Injuries
Authors: O'Connell PW , Johnson RJ , Mogan JV
Published: December 2008

Seven cases of carpometacarpal (CMC) dislocation of the thumb were followed up after being seen at the Sugarbush Ski Area Clinic and at other Vermont ski areas during the 1981 through 1982 and 1982 through 1983 seasons. No previous cases had been seen among 3171 ski injuries treated at the Sugarbush Clinic over the past ten years. All injured skiers reported jamming their thumb longitudinally into the snow with most retaining the ski pole in their palm. All cases were initially treated with reduction and immobilization in a thumb spica cast, usually for 3 to 5 weeks. Two cases required further immobilization with percutaneous Kirschner wires. None of the seven patients in our study required ligament reconstruction or repair, and all had either good or excellent results based on strength, stability, pain, and range of motion (ROM). Our study suggests that retention of the ski pole in the hand during a fall may play a significant role in dislocation of the CMC joint. Most cases can be treated with simple reduction and immobilization with good to excellent results.
Results of an ASTM E-4 Round-Robin on the Precision and Bias of Measurements of Microindentation Hardness Impressions
Authors: Vander Voort GF
Published: December 2008

An interlaboratory test program was conducted by ASTM Committee E-4 on Metallography, according to ASTM Practice for Conducting an Interlaboratory Test Program to Determine the Precision of Test Methods (E 691), to develop information regarding the precision, bias, repeatability, and reproducibility of measurements of Knoop and Vickers microindentation impressions. Both types of indents were made using loads of 25, 50, 100, 200, 500, and 1000 gf (five of each type at each load) using three ferrous and four nonferrous specimens of varying hardness. The indents were measured by 24 laboratories. Analysis of the test results according to E 691 have been used to prepare a Precision and Bias section for ASTM Test Method for Microhardness of Materials (E 384).

Fourteen laboratories measured the indents in the three ferrous specimens and nine labs had similar Vickers hardness measurements. Of the remaining five laboratories, two were consistently lower while three were consistently higher in measured Vickers hardness. For the Knoop indents in the ferrous specimens, the results were similar except that one lab that got consistently lower Vickers hardnesses had acceptable Knoop hardnesses.

Twelve laboratories measured the indents in the four nonferrous specimens, and the hardness data were in better agreement than for the ferrous specimens due to the much larger indents in the nonferrous specimens. For the Vickers data, one laboratory was consistently lower in hardness while two laboratories were consistently higher in hardness. For the Knoop data, three laboratories were consistently lower in hardness while one laboratory was consistently higher in hardness.

Three laboratories measured both ferrous and nonferrous Vickers and Knoop indents, although one of these laboratories (N) measured only one of the nonferrous specimens. Test results for laboratories N and O were acceptable while those for laboratory M were consistently lower in hardness for all specimens and for both Knoop and Vickers indents. This result suggests a consistent bias either in the calibration or the manner in which the indents were sized.

The repeatability and reproducibility intervals increased with increasing specimen hardness and decreasing test load, that is, with decreasing indent size. The within-laboratory and between-laboratory precision values improved as the specimen hardness decreased and the test load increased, that is, as the indent size increased.
Factors That Affect the Accuracy of Indentation Hardness Tests
Authors: Tobolski EL
Published: December 2008

Rockwell, Brinell, and microhardness are the common indentation hardness tests discussed in this paper. Indentation hardness testing, in many cases, can be properly considered a nondestructive test since the part is usable after the test. The destructive effect at the test point, however, makes it impossible to retest the same point to verify the accuracy of the testing process. It is, therefore, critical that the first test be performed with a high degree of accuracy. The following items can seriously affect that accuracy: test material, testing instrument, operator, and environment.
Measurement of Rapid-Loading Fracture Toughness JId
Authors: Satoh M , Funada T , Urabe Y , Hojo K
Published: December 2008

The effect of the loading rate on elastic-plastic fracture toughness, which defines stable crack initiation, has not been clear; therefore, the test method of elastic-plastic fracture toughness under rapid loading (rapid-loading fracture toughness JId) has not yet been established in ASTM Test Method for JIc, a Measure of Fracture Toughness (E 813-81).

The authors studied the JId test method by using a high-speed servohydraulic testing machine, by which the rapid-loading fracture toughness test could be done in accordance with ASTM Test Method for Plane-Strain Fracture Toughness of Metallic Materials (E 399-83 ANNEX A7). We evaluated the applicability of the unloading compliance method to determine the stable crack initiation under rapid loading by comparing the results with the multiple specimen method.

We also applied the electric potential method, which is expected to be able to detect crack growth continuously to determine the stable crack initiation. Results are as follows. 1. The unloading compliance method is applicable to rapid-loading tests.JId measured by the unloading compliance method is the same as that obtained by multiple specimen method. 2. JId based on the electric potential method is about the same as that of the unloading compliance method. 3. JId depends on loading rate. Transition temperature between the brittle-ductile region tends to be higher as the loading rate increases.
Accuracy of Multiaxial Fatigue Testing with Thin-Walled Tubular Specimens
Authors: Lefebvre DF , Ameziane-Hassani H , Neale KW
Published: December 2008

In this study, we attempt to quantify the effects of certain factors which control the accuracy of multiaxial low-cycle fatigue results obtained from thin-walled tubular specimens. This investigation includes: 1. Some experimental observations regarding the behavior of thin-walled tubes under cyclic axial load and internal-external pressure. 2. A finite-element study of the influence of specimen shape. Tubular specimens of 27-mm diameter with different gauge lengths, wall thicknesses, and transition areas are analyzed. In each case, stress and strain distributions through the wall thickness in the gauge length and the critical strain amplitude at buckling are determined for different combinations of axial load and internal-external pressure. 3. Some experimental fatigue results obtained from tubular specimens under cyclic biaxial loading.
Requirements for the Permitted Size of the Alignment Errors of Load Frames for Fatigue Testing and a Proposal for a Relevant Measuring Method
Authors: Baten RJH , d'Haen HJ , Jacobs FA , Muller MK , van Riesen PE , Tjoa GL
Published: December 2008

This paper covers the activities of the working party on Requirements for Fatigue Testing Machines [3].

Requirements and recommendations are specified with respect to the alignment of load frames for fatigue testing, including load cell and (hydraulic) actuator.

Subsequently, a method is proposed to measure the alignment errors. Calculations are made and a series of alignment specimens are designed for load frames of different capacities to check whether or not the bending stresses under load, due to misalignment, correlate with the off-load measured alignment errors. Designs for clamping the alignment specimens are given and applied for the measurements as well.

The alignment errors to be specified, defined, and measured include: 1. Eccentricity. 2. Angular deflection. 3. Alignment error.

Although a literature survey was carried out, there appeared to be no specific requirements for the alignment accuracy of load frames. International standards mainly set out requirements concerning the accuracy of the load cell and the maximum allowable specimen bending at zero load. These standards, however, have omitted the effect of the alignment errors as defined in this paper.

Results of measurements obtained with the described method lead to a recommendation for its application, either in part or in total.
End Constraint and Alignment Effects in Three- and Four-Point Reverse Bending Tests
Authors: Bowman WD
Published: December 2008

A specimen loaded in bending when rigidly clamped on the ends by specimen grips will undergo an axial force due to the conflict between the grips' resistance to move and the specimen ends' intention to move inwards. By mounting the grips on flexures and allowing them to move with the specimen ends while still applying a bending moment, pure bending on the specimen will result. A constant moment along the length of the specimen can be obtained by applying equal and opposite force couples to the ends of the specimen via the grips.

This paper examines the effects of specimen end conditions and alignment on test results obtained from three- and four-point reversing bend tests. Various end conditions can exist, such as fixed-fixed, fixed-free, free-free, and a special case in which the end condition is a combination of fixed and free. Each of these end conditions imposed on a specimen in bending is evaluated as to its contribution to axial forces and its ability to provide a true bending moment on the specimen. The effects of bending out of plane with respect to the specimen axis are also discussed.

This paper also describes an apparatus for testing specimens in three- and four-point reverse bending in which the axial force in the specimen is reduced.
Accuracy of High-Temperature, Constant Rate of Strain Flow Curves
Authors: Lenard JG , Karagiozis AN
Published: December 2008

The components that make up a mathematical model of hot strip rolling include the conditions of equilibrium, roll deformation, friction at the roll-strip interface, and material behavior. The consistency and accuracy of the predictive capability of the model will depend on the quality and rigor of the representations of these components. This paper deals with one of the least tractable parameters—material behavior.

The difficulties associated with the determination of constitutive behavior are discussed. It is suggested that a standard method of testing for high-temperature strength be established.
Simple Stress Sensor: Utilizing of Stretcher Strains
Authors: Taniuchi K
Published: December 2008

This article concerns an attempt to utilize stretcher strains to determine the stress concentration factor in the elastic-plastic state of steel strip specimens having semicircular notches. The dangerous section of steel gear tooth profiles is also brought under examination. In both cases, the utilization of stretcher strains provides successful results. For this undertaking, the observation of the striped pattern was made solely by the naked eye, without the use of a measuring instrument.

The examples shown will illustrate that the use of stretcher strains is a simple and convenient stress sensor.
A Survey of the Experimental Determination of Precision in Materials Research
Authors: McClelland HT , Birkland ML
Published: December 2008

The purpose of this survey was to determine the extent to which the precision of data was determined during the course of experimental studies in materials research. Eight technical journals were sampled.

It was found that 23 ± 13% (at the 95% confidence level) of the papers in the journals examined reported experimentally determined precision. It would appear from these results that an effort should be made to train research personnel in modern experimental procedures.
Eye and Face Injuries in High School Hockey: Cutting Down the Risks
Authors: Mastrangelo FA
Published: December 2008

In 1970, two out of every three hockey players suffered some type of facial injury. As a result of standards, certification of face protectors, and rules for mandatory protective equipment, eye, face, and dental injuries have almost been eliminated. This paper reviews how the modern athletic trainer coordinates the observance of the rules, the choice of protective equipment for the face and head, and monitoring of equipment adjustment for optimum performance and safety.
The Ice Hockey Face Guard: Health Care Costs and Ethics
Authors: Vinger PF , Bentkover JD , Sullivan R , Kalin JG
Published: December 2008

The hockey face guard has been mandated for many levels of organized hockey playing in the United States and Canada. The widespread use of the hockey face guard has resulted in a saving in health care costs of $10 million annually in the United States alone. In this paper, the use of hockey facial protective equipment from the standpoint of ethical considerations will be discussed in terms of each level of hockey, from Youth sports through College and professional leagues.
Cervical Spine Fractures: Mechanisms, Neck Loads, and Methods of Prevention
Authors: Bishop PJ , Wells RP
Published: December 2008

Cervical spine fractures, particularly of the burst type, caused by axial compressive loading of the spine, have been an increasing problem in hockey for the past several years. The mechanism associated with such injuries involves a headfirst collision in which the crown of the head strikes the boards, goalpost, or another player with the neck partially to fully flexed. Mechanical simulation of these collisions using an anthropometric test dummy has yielded compressive forces of approximately 5000 N in the C4-C5-C6 region of the cervical spine from impact speeds of only 1.8 m s-1. The relationship between these forces and human tolerance limits is illustrated. Computer simulations of these accidents demonstrate that prevention cannot be accomplished by increasing the amount of padding material in the crown of the helmet. Other preventive strategies are suggested.
Safety Factors in the Modern Ice Hockey Skate Blade
Authors: Couture G
Published: December 2008

Concern for injuries associated with modern hockey skate blades occurred during the 1950s and was related to the rear open-end design of the all-steel tubular blade. Sharpening procedures produced a sharp point at the end of the blade, which was associated with saber-like injuries to opponents. As a result, the plastic (or metal) safety tip was invented and its use was made mandatory in hockey rules.

The advent of the modern plastic-metal blade with its closed end appeared to eliminate the problem, but the high breakage rate produced new types of potential hazards, as well as the inconvenience of broken blades and associated extra costs.

This report describes the evolution of today's hockey blades and their relationship to the ASTM Performance Specification for Ice Hockey Skate Blades (F 737-86).
Kinematic Analysis of the Talocrural and Subtalar Joints During the Hockey Skating Stride
Authors: Hoshizaki TB , Kirchner G , Hall K
Published: December 2008

Few studies have been undertaken describing the kinematics of either the subtalar or talocrural joints during the ice hockey skating stride. Unfortunately, the lack of scientific data severely restricts the effectiveness of hockey skate design innovations. The purposes of these investigations were, first, to characterize the kinematics of the talocrural and subtalar joints during the most common form of ice hockey skating, forward acceleration. Secondly, these studies investigated the interaction of the ankle and the hockey boot during forward acceleration, and, finally, they describe differences in the kinematics of the ankle while skating in a variety of high-quality hockey skates. Range of motion of the subtalar and talocrural joints was measured under static and dynamic loads for dorsal and plantar flexion and for supination and pronation. Dynamic values were obtained while the skaters were accelerating, turning, starting, and stopping. Conclusions from the data revealed that the type of hockey skate an athlete wears can effect the range of motion of the talocrural and subtalar joints during the skating stride. It was also observed that the molded skates used in this study did not restrict the range of motion of the ankle to any greater degree when compared to other skates.
Ice Hockey Protective Equipment—Its Value, Capabilities, and Limitations
Authors: Hoerner EF
Published: December 2008

Concerns and a discussion on ice hockey protective equipment are presented, with the emphasis on human factors and the interfacing between human factors and the equipment that comes in the design of protective equipment. These concerns include sizing, coverage, anatomical shapes, equipment configurations, materials available for equipment manufacture, and the nature of the sports and games in which the equipment is used. Special emphasis is directed to the effects of aging and the life cycle of the protective equipment itself.
Research and Development of Hockey Protective Equipment—A Historical Perspective
Authors: Clement L , Jones D
Published: December 2008

This paper discusses research and development of hockey protective equipment from a historical perspective, with emphasis on the products of Cooper Canada Ltd.
Utilization of Low-Quality Aggregates in Asphaltic Mixtures in the Eastern Province of Saudi Arabia
Authors: Abdulshafi A , Al-Dhalaan MA
Published: December 2008

Utilization of low-quality aggregates in the eastern province of Saudi Arabia as well as in most Gulf areas is becoming a necessity. In this area, the definition of low-quality aggregates is more related to surface chemistry characteristics and salt content than to particle strength, porosity, surface texture, organic and fines or any other deficiency measures. Stripping, ravelling, and rutting are the major distress manifestations observed in asphaltic mixtures. Rutting is related to mix flow. Bleeding and shoving problems are also observed but to a lesser extent. One effective solution to the above is the cement coating of the coarse aggregate, thereby eliminating surface chemistry debonding behavior (stripping) and increasing the overall mixture stiffness. Several laboratory testing methods on aggregates (such as specific gravity, water absorption, abrasion, and soundness) and on asphaltic mixtures (such as stability, modulus of resilience, creep and rutting, fracture toughness, and index of retained strength) have been performed. Laboratory test results on cement-coated and uncoated aggregates as well as on their asphaltic mixtures clearly indicate the improvements obtained by cement coating technique. These improvements include more than 30% increase in Marshall stability with flow remaining within specification range, improved coating and resistance to stripping, increased tensile strength and resilient modulus, more than 90% immersion-tensile strength ratio, and increased fatigue life.
Use of Thin Asphalt Surfaces over Aggregate Base Course for Heavy-Axle Truck Loads
Authors: Dukatz EL
Published: December 2008

Crushed-stone base on roadways provides structural integrity, facilitates drainage, and minimizes construction costs. At this time, however, it is not being used to its full potential in pavement construction: recent laboratory tests show that a properly designed and constructed crushed-stone base is much stronger than widely believed.

A test pavement project in North Carolina involving the Vulcan Materials Company (VMC), the North Carolina Aggregates Association (NCAA), and the North Carolina Department of Transportation has been undertaken to provide data on the effectiveness of pavements constructed with thin asphalt surfaces over thick aggregate base courses. State Route 1508 in North Carolina, constructed in early 1985 and designed to have a five-year life, is one of the test roads used in the project. The road has been subjected to 60% of its design traffic in 18 months and shows minimal amount of distress. Because it is trafficked by all incoming and outgoing aggregate haulers from a VMC quarry (for which it was constructed), SR 1508 is of interest to engineers concerned about the deformation of pavements (rutting) due to the loadings of heavy truck traffic.
Hot-Mix Asphalt Moisture Susceptibility Problems: The Need to Test and Specify via a Common Procedure
Authors: Dukatz EL , Phillips RS
Published: December 2008

One of many problems facing the hot-mix asphalt designer, specifier, and producer is how to properly predict the behavior of the asphalt concrete when exposed to moisture. At present, a broad spectrum of accelerated test procedures are available to the engineer that to some degree “predict” the moisture susceptibility of the mix. These procedures include the Lottman, the modified Lottman, and the boiling water stripping test. With the number of procedures available, and with different procedures being specified in different parts of the country, the engineer must answer the question of which procedure best suits the prediction of future performance.

Once a procedure is chosen, then the method by which the data are interpreted becomes important. For the Lottman procedures, splitting tension specimens are often prepared at 7 ± 1% air voids. Grossly different and misleading results will be obtained if conditioned specimens having 8% air voids (7 + 1%) are tested and compared to control specimens having 6% air voids (7 - 1%). While the preceding combination would suggest less than actual performance, the opposite is possible if the extremes are reversed. Either case is undesirable and can prove costly if a local aggregate is excluded for a false low value or if a poor material is accepted for a false passing value.

The authors suggest that a better procedure is to prepare specimens representing the low (4 to 6%), midpoint (6 to 8%), and high (8 to 10%) end of the air void range allowed for the test. This should be done for both the conditioned and the control specimens. After determination of the splitting tensile strength for each specimen, the results should be plotted as tensile strength (St) versus percent air voids for each condition. The strength at 7% voids for each test condition can be determined by using graphical interpolation and a valid comparison can be made for all conditions.

Another suggestion of the authors is that a minimum conditioned tensile strength at 7% air voids be specified in conjunction with a minimum retained tensile strength ratio (TSR). The TSR requirement may be waived for treated asphalt mixes in which the conditioned tensile strength exceeds the minimum specified tensile strength and is also higher than the tensile strength of the unconditioned untreated mix.
Temper Embrittlement Susceptibility and Toughness of A 508 Class 3 Steel
Authors: Tavassoli A-A , Soulat P , Pineau A
Published: December 2008

A correlation has been established between the scatter in Charpy and fracture toughness results of an ASTM Specification for Quenched and Tempered Vacuum-Treated Carbon and Alloy Steel Forgings for Pressure Vessels (A 508-84a) Class 3 (UNS K12042) pressure vessel forging steel and the appearance of intergranular facets on the rupture surfaces of specimens tested at low temperatures. Extent of the intergranular rupture has been found to increase with prolonged aging at 500 to 550°C or following an embrittling treatment known as step cooling. Both intergranular rupture and the resultant increase in ductile to brittle transition temperature were reduced or eliminated by a de-embrittling treatment at temperatures ranging from 630 to 660°C, with optimum results obtained at 640°C. Auger analyses carried out on specimens exhibiting cleavage and intergranular rupture have shown segregation of carbon, molybdenum, sulfur, and, in particular, phosphorus at the grain boundaries.

A statistical analysis based on a local rupture criterion is used to describe the probability of intergranular and cleavage failures. Based on the observations made, the main cause of scatter in low temperature results is concluded to be heterogeneous segregation of impurities in thick sections with a corresponding shift in ductile to brittle transition temperature. A slight increase in austenitization and de-embrittling temperatures is suggested in order to reduce segregation and improve toughness.
The Effect of Residual Elements on the Tensile Strength of Heavy Carbon Steel Forgings, Heat Treated for Optimum Notch Toughness
Authors: Nisbett EG
Published: December 2008

Residual elements are shown to have influenced the tensile strength of large, heavy section carbon steel forgings that had been heat treated for optimum Charpy V notch properties. The forgings had been made to a specification based on an early revision of ASTM Specification for Forgings, Carbon Steel, for Pressure Vessel Components (A 266-84a, UNS K035 06), but with several provisions of the more modern ASTM Specification for Quenched and Tempered Vacuum-Treated Carbon and Alloy Steel Forgings for Pressure Vessels (A 508-84a, UNS K13502). While not a factor in the particular contract described, the results are also discussed in terms of the use of carbon equivalency in the composition control of forgings for weldability purposes.
The Effects of Phosphorus and Boron on the Behavior of a Titanium Stabilized Austenitic Stainless Steel Developed for Fast Reactor Service
Authors: Hamilton ML , Johnson GD , Puigh RJ , Garner FA , Maziasz PJ , Yang WJS , Abraham N
Published: December 2008

Austenitic stainless steels are used for core component materials in liquid metal cooled reactors (LMRs). To extend the lifetime of LMR fuel assemblies, considerable effort was expended by the U.S. breeder materials program to find ways to minimize radiation induced dimensional changes (swelling and creep) and to maximize the creep rupture strength. After various elements were shown to affect strongly swelling and creep behavior, compositional modifications to a commercial grade austenitic stainless steel (American Iron and Steel Institute 316 UNS S31600) produced an alloy with significant improvement in swelling resistance over the standard 300 series alloys. Changes were primarily in the concentrations of chromium, nickel, silicon, and titanium. ASTM Specification for Austenitic Stainless Steel Tubing for Breeder Reactor Core Components (A 771-83) was approved in 1983 for the new alloy, designated UNS S38660.

Substantial improvement can be produced in the creep rupture behavior of this alloy. Elements such as phosphorus and boron, typically present in trace quantities, have a significant influence on the creep strength of austenitic stainless steels. Several heats of alloy S38660 were made that systematically varied the phosphorus and boron contents. Uniaxial creep tests were conducted at 704°C (1300°F) to evaluate the effects of these elements on the creep rate and the rupture life. The results of these tests were used to guide the production of reactor grade fuel pin cladding for further evaluations. Pressurized tube specimens were tested in the laboratory and also in a fast reactor. Results of these investigations have shown that the elements phosphorus and boron, present in minute but controlled amounts, increase both the in-reactor and ex-reactor rupture life and reduce both in-reactor swelling and creep rate. Microstructural evaluations were also conducted to help ascertain the mechanisms by which the improved properties were obtained.
The Influence of Current Supply Type on the Composition, Microstructure, and Mechanical Properties of C-Mn and C-Mn-Ni Shielded Metal Arc Welds
Authors: Abson DJ
Published: December 2008

An American Welding Society (AWS) E7016 type C-Mn electrode and an AWS E7018 type C-Mn-Ni electrode were each used to produce a series of butt welds in 25-mm (1-in.) thick British Standard (BS) 4360 50E (C-Mn-Nb) steel plate in the flat (1G) position. For each consumable, direct current (DC) reverse polarity (electrode positive), DC straight polarity (electrode negative), and AC power supplies were each used for a complete panel. In addition, DC straight polarity was employed for vertical-up (3G) welding with the C-Mn-Ni electrode. The chemical composition, strength, microstructure, and toughness of the deposits were studied in the as-welded condition.

For the C-Mn-Ni 1G welds (and to a lesser extent for the C-Mn welds), manganese and silicon decreased in the order DC reverse polarity, AC and DC straight polarity. For both consumables, there was a concomitant increase in nitrogen content. There were no associated changes in strength or microstructure, but there was generally a progressive decrease in crack tip opening displacement (CTOD), measured at - 10°C, and in Charpy toughness. As a consequence of strain aging, Charpy toughness was lower in the root than in the fill region.

The 3G DC straight polarity C-Mn-Ni deposit had higher strength in the root and higher Charpy toughness than the corresponding 1G deposit. The CTOD of the former was lower and showed much more scatter, to which locally low toughness regions (revealed by fractographic examination) contributed.
The Influence of Current Supply Type and Arc Length on C-Mn, C-Mn-Ni, and C-Mn-Ti-B Shielded Metal Arc Deposit Nitrogen and Oxygen Contents
Authors: Abson DJ
Published: December 2008

Nitrogen and oxygen contents have been determined for welds simulating root and hot passes, and deposited with progressively longer arc lengths to give arc voltages in the range 18 to 28 V. Commercial basic-coated C-Mn, C-Mn-Ni, and C-Mn-Ti-B shielded metal arc electrodes were employed in the flat (1G) position with DC straight polarity (electrode negative), DC reverse polarity (electrode positive), and alternating current (AC) supplies.

In all deposits, nitrogen content increased with increasing arc length, with the C-Mn-Ti-B deposits showing the most rapid rise. The highest low voltage nitrogen levels and the most rapid increases always occurred for DC straight polarity welding, which gave >0.06% nitrogen at the highest arc voltage for each of the consumables. Deposit nitrogen content always exceeded the level in the core wire, but approached it at the lowest voltage for DC reverse polarity welds, with two of the C-Mn-Ti-B deposits showing the lowest nitrogen contents.

Deposit oxygen contents were not related to core wire levels. For DC straight polarity deposits, oxygen increased progressively over the voltage range studied. For DC reverse polarity deposits, oxygen decreased progressively for AWS E7016 type electrodes, and showed an initial decrease and a subsequent increase for AWS E7018 type electrodes. The AC deposits showed either a small increase or decrease at low arc voltages and an increase at higher arc voltages.

The findings reflect the incomplete shielding provided by the gas shield and slag layer at high arc voltages, particularly for DC straight polarity welding. They suggest that reactions involving the molten droplets emanating from the electrode tip are important in influencing deposit nitrogen content, and that those occurring in the slag layer at the surface of the weld pool are important in influencing deposit oxygen content.
A Method for Developing Postweld Heat Treatments and Evaluating Effects of Residual Elements on Heat-Affected Zone Tempering Resistance
Authors: Biron RH , Kreischer CH , Melilli AS
Published: December 2008

A method was developed to define a postweld subcritical heat treatment to provide optimum ductility of the heat-affected zone. The results have been used to define the post-weld heat treatment included as part of welding procedure qualification tests. By themselves, required qualification tests, which involve tensile, bend, and sometimes impact, can be misleading because they are not primarily designed to evaluate heat-affected zone ductility. The test method involved generating a heat-affected zone (HAZ), extracting a series of as-welded cross sections, heat treating each section at varying times and temperatures, measuring the peak heat-affected zone hardness, and defining the heat-affected zone ductility by correlating the peak HAZ hardness with the Hollomon-Jaffe parameter associated with each time and temperature. Several heats of CrMo and CrMoV turbine alloys were studied in this manner to define their weld HAZ tempering response and to evaluate specific tempering effects of residual alloy element content.
The Effect of Phosphorus on the Mechanical Properties of X-70 Line Pipe Steel
Authors: Kapadia BM
Published: December 2008

The effect of phosphorus content on the base plate properties and coarse-grained heat affected zone (HAZ) toughness of X-70 Cb-V line pipe steel has been studied. Three laboratory heats were melted with phosphorus contents of 0.001, 0.009, and 0.027%. The ingot sections were control rolled to 13-mm (0.512-in.) thick plates employing a single delay 4T rolling practice. The HAZ toughness was evaluated on specimens subjected to a weld simulation thermal cycle corresponding to 1315°C (2400°F) peak temperature in the HAZ of a submerged arc weld deposited with a heat input of 3 kJ/mm (76 kJ/in.).

The as-rolled plates showed no significant effect of phosphorus variation on their microstructure, strength, or impact properties over the range investigated. The steels exhibited similar coarse-grained HAZ microstructures and hardnesses. Although the transition temperatures of the steels were significantly raised in the simulated HAZ condition, as expected, the variation in phosphorus content appeared to have little or no significant effect on toughness. Fractographic examination of the simulated HAZ impact specimens showed similar fracture appearances with no evidence of intergranular fracture.

The conclusion is that a specification limit of 0.010% maximum on the phosphorus content in Arctic grade line pipe steels may be unduly restrictive for ensuring superior base plate and HAZ toughness properties, as well as adequate resistance to hydrogen induced cracking (HIC).
A Study of Graphite/PEEK Under High Temperatures
Authors: Ramey J , Palazotto A
Published: December 2008

An experimental evaluation of graphite/PEEK, APC-2, was carried out on specimens with various size holes acting under tension and compression loading. Quasiisotropic symmetrical laminates were tested at RT, 121, 135, and 149°C, and the Pipes three-parameter failure criterion was correlated with experimental results. Scanning electron microscopy photographs were used to determine specific notch effects on failure modes.