bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessment of the Impact of Medication Therapy Management Delivered to Home-Based Medicare Beneficiaries
Authors: Welch Erin K , Delate Thomas , Chester Elizabeth A , Stubbings Troy
Published: March 2009

Background:

Medication Therapy Management (MTM) is a voluntary patient participation program mandated for Medicare Part D sponsors by the Centers for Medicare and Medicaid Services for chronically ill beneficiaries with high medication costs/utilization.

Objective:

To assess the impact of an MTM program on mortality, healthcare utilization, and prescription medication costs and to quantify drug-related problems (DRPs) identified during MTM.

Methods:

This nonrandomized controlled study was conducted among beneficiaries who were targeted for MTM in 2006. The MTM intervention was designed to identify potential DRPs, educate the patient/caregiver about appropriate medication use, and ensure that the patient was appropriately integrated into clinical services. Data were collected from administrative databases and manual chart abstractions. Study outcomes included all-cause death (primary outcome), hospitalization, and emergency department (ED) visit rates and medication cost changes in the 180 days following MTM targeting and quantification of DRPs. Multivariate logistic regression was used to adjust the outcomes for baseline risk and other potential confounders. A mock MTM intervention was performed for beneficiaries who declined MTM and died, were hospitalized, and/or made an ED visit.

Results:

A total of 459 opt-in and 336 opt-out beneficiaries who agreed and declined, respectively, to receive MTM were included in the analysis. Beneficiaries who opted in were less likely to die compared with beneficiaries who opted out (adjusted OR [AOR] 0.5; 95% CI 0.3 to 0.9) but were more likely to have had a hospitalization (AOR 1.4; 95% CI 1.1 to 2.0) and an increase in medication costs (AOR 1.4; 95% CI 1.1 to 1.9) during follow-up. There was no difference in ED visit rates. At least one DRP was identified in more than 83% of beneficiaries in both groups, with the most common DRP being drug–drug interaction.

Conclusions:

Our investigation supports the use of MTM, with its increased coordination of information between healthcare providers and patients, since it may impact mortality positively in a population of high-risk Medicare beneficiaries.
Efficacy and Safety of Modafinil in the Treatment of Cancer-Related Fatigue
Authors: Cooper Maryann R , Bird Heather M , Steinberg Michael
Published: March 2009

Objective:

To review the efficacy and safety of modafinil in the treatment of cancer-related fatigue (CRF).

Data Souces:

Literature was accessed via MEDLINE (1950–week 3, November 2008), International Pharmaceutical Abstracts, and Google Scholar using the terms modafinil, cancer, and fatigue. Reference citations from articles identified were reviewed.

Study Selection and Data Extraction:

All English-language publications identified were analyzed for significance. Studies relevant to the objective were used, including 2 prospective open-label studies, one randomized double-blind, dose-controlled trial with an open-label extension, and one Phase 3 randomized, placebo-controlled, double-blind trial.

Data Synthesis:

Fatigue is a nearly universal adverse effect of cancer and its treatment that is unrelated to physical exertion, is not relieved by sleep or rest, and negatively affects quality of life. Modafinil is a central nervous system stimulant with minimal toxicity and a low propensity for abuse. Clinical data demonstrate that modafinil significantly reduces fatigue in patients who have received cancer treatment or are currently undergoing chemotherapy. Additional benefits include improvement in cognitive function, mood, general activity, walking ability, normal work ability, relations with other people, and enjoyment of life. Limitations of the available data include open-label design in 3 of the 4 studies; the absence of numerical results of fatigue assessments in the abstract of 1 trial, preventing the determination of clinical significance; and the full inclusion/exclusion criteria, which were not included in the published abstracts. These limitations leave readers without a clear picture of the study populations. Finally, different patient populations at different points in treatment with varying durations of therapy were used, which makes extrapolation of data to the general population challenging.

Conclusions:

Further randomized placebo-controlled trials are necessary to amass evidence for the effective and safe use of modafinil for CRF; however, if traditional therapies have failed or are intolerable, modafinil can be considered a treatment option.
Risk of Severe Gastrointestinal Events in Women Treated with Monthly Ibandronate or Weekly Alendronate and Risedronate
Authors: Blumentals William A , Harris Steven T , Cole Raymond E , Huang Liping , Silverman Stuart L
Published: March 2009

Background:

Bisphosphonate (BP)-related gastrointestinal (Gl) adverse events can lead to discontinuation of osteoporosis treatment. Irritation of the GI tract related to BPs may be worsened by more frequent administration.

Objective:

To compare the number of women who experienced severe GI events within 3 months of starling once-monthly oral ibandronate with those starting once-weekly oral BP (alendronate or risedronate).

Methods:

In a retrospective database study design, eligible women with a new prescription for monthly ibandronate were propensity-matched to women with a new weekly BP prescription. Patients had continuous health plan enrollment for 6 months prior to the index date and for 3 months after the index date. Women with previous intravenous BP treatment, Paget's disease, or oral BP treatment within the 6-month preindex period were excluded. Severe GI events (including acute events involving perforation or bleeding/perforation) within 3 months of treatment initiation were identified by ICD-9 and Current Procedural Terminology codes. A post hoc analysis assessed treatment discontinuation after severe GI events. GI-related healthcare utilization rates and costs were also compared,

Results:

Of the 8608 patients per group, 45 (0.52%) who were receiving monthly ibandronate and 70 (0.81%) of those receiving weekly BP treatment experienced a severe GI event. Ibandronate patients had a 36% reduction in the risk of severe GI events compared with weekly BP users (OR 0.64, 95% CI 0.44 to 0.93). Significantly more women receiving a weekly BP discontinued treatment after a severe GI event compared with those receiving ibandronate (100% vs 55.6%: p< 0.001). Most healthcare utilization outcomes were not significantly different between the 2 groups; outpatient visits were significantly higher for ibandronate (p = 0.02). Costs were not significantly different between the 2 groups.

Conclusions:

Patients receiving monthly ibandronate therapy had a significantly reduced risk of severe GI events compared with those receiving weekly BP treatment. In addition, patients receiving a weekly BP were more likely to discontinue treatment after a severe GI event.
Patient Needs and Sources of Drug Information in Singapore: Is the Internet Replacing Former Sources?
Authors: Ho Cai-Hong , Ko Yu , Tan Mui-Ling
Published: March 2009

Background:

Patients are exposed to a broad range of drug information (DI) sources; among them is the Internet, which has been increasingly used over the years, especially by adolescents.

Objective:

To identify patients' needs and common sources of DI: examine the differences in use of DI sources among groups, by age and sex; and better understand patients' use of the Internet as a source of DI.

Methods:

A quota sample of 201 outpatients from National University Hospital in Singapore was surveyed. A questionnaire was developed to examine patients' needs for and common sources of DI as well as their experience with and attitudes toward using the Internet as a DI source.

Results:

Physicians (83.1%) and pharmacists (57.7%) were reported to be the most commonly used sources of DI regarding prescription drugs (n = 201), whereas pharmacists (40.9%) and relatives or friends (40.9%) were the most commonly reported sources for information about nonprescription drugs (n = 149). Respondents most commonly sought DI about adverse effects (72.6%), dosing (54.7%), and indications (54.2%). Among Internet users, people aged 31–50 years were more likely than those in other age groups to search the Internet for DI (p < 0.001). The Internet was considered to be a convenient source with a broad range of information; however, patients faced both the inability to find needed information and uncertainty about information reliability when searching (or DI on the Internet.

Conclusions:

Pharmacists play an important role in counseling patients about prescription and nonprescription drugs. There is a need to educate patients on how to locate and evaluate DI on the Internet.
Sustaining Ambiguity and Fostering Openness in the (Design) Learning Environment
Authors: Valentine Louise , Ivey Marlene
Published: March 2009

Knowledge economies possess a number of key characteristics that require designers to work and cope with the growing occurrence of unpredictable scenarios. To mindfully engage in an uncertain world, student designers must develop critical thinking, social interaction and the ability
to manifest design in a diversity of professional and industrial sectors. They need to develop the ability to equip themselves with the skill of sustaining and renewing knowledge throughout their careers. This demands that design extend its teaching beyond revealing the origins and nature
of design to include skills of interrogation, which allow individuals to challenge existing and established theories and practices.

The intention of this paper is to articulate a teaching and learning philosophy for contemporary design, and exemplify practice through design projects and
skill development from one postgraduate design programme. It discusses the philosophy of mindfulness and refers to the activities of rhetoric and visual thinking as means of nurturing communication of the designer's thinking. The nature rather than the content of teaching and learning
is of key concern, and as such the practicalities of teaching and applying mindful learning are referred to but purposefully not described, analysed or argued for. In closing, a new strategy for design teaching and learning is proposed.
Off-campus learning and employability in undergraduate design: the Sorrell Young Design Project as an innovative partnership
Authors: Butcher John
Published: March 2009

This article reports on research which explored the opportunity for extra-curricular undergraduate learning afforded by the Young Design Project (YDP), aimed at bringing together HE Design students, industry and schools. The research was undertaken in the context of the importance attached
to employability as a key driver for recent policy developments in Higher Education (see Leitch review and Cox report), as well as the political importance of Widening Participation initiatives between HEIs and schools. This research investigated the second iteration of the YDP in 2007, with
32 undergraduate students from two design degrees at University College Falmouth (BA Graphic Design and BA Spatial Design) on a project based in four Cornish schools (three secondary, one primary). The research sought to answer the question: what do undergraduate students learn from working
with pupils as clients and industry practitioners in the context of a school-based project? This question is explored through a case study drawing on four triangulated phases of data collection: desk research of relevant policy documentation; pre-project semi-structured questionnaire; post-project
focus group interviews and individual face-to-face interviews with key gatekeepers. As well as reflecting on the opportunity to engage with innovative learning in design, the findings offer fruitful insights to HE practitioners and policy makers considering issues around off-campus learning.
This research recommends notions of employability be subject to greater scrutiny in HE policy, since a key finding from this research is the crucial importance of appropriately resourced authentic project partnerships for deep and worthwhile undergraduate learning to take place.
Characterization of Locked Sand from Northeastern Alberta
Authors: Abdelaziz Tarek S. , Derek Martin C. , Chalaturnyk Rick J.
Published: March 2009

A comprehensive experimental investigation was carried out on a lower Cretaceous friable intact sand formation retrieved from northeastern Alberta. Index tests, microstructural observations, and mineralogical composition analyses were carried out to confirm that this formation fits into the locked sand category. The significance of the local strain measurements in revealing salient deformation characteristics of this formation was explored under uniaxial stress conditions. The test results showed that the characteristics of this formation are in keeping with the characteristics of locked sands. The intimacy between the grains stems from authigentic quartz creating interlocking rather than cementation. The results also revealed that local axial and lateral strain measurements are essential for proper behavioral characterization and failure mechanism interpretation of locked sands. The interlocked fabric results in an exceptionally high uniaxial strength and elastic axial stiffness. The disruption of the interlocking is achieved through the lateral expansion of the sample and formation of dilation bands.
Effects of Particle Shape and Gradation on the Results of Miniature DCP Tests in Sand
Authors: Muszynski Mark R.
Published: March 2009

Miniature dynamic cone penetrometer (mDCP) tests were completed to investigate the general effect that particle shape and size gradation may have on penetration resistance. This testing provides preliminary results for planning purposes for a future testing program that will include full-scale dynamic cone penetrometer (DCP) testing on sands having varying physical properties and characteristics. Generally, the blow counts per increment became greater with increasing relative density for dry and moist sands, as expected. Angular sands increased the blow counts, whereas rounded sands yielded lower blow counts for the same relative density and grain size distribution. At high relative densities, the effect of particle shape was generally more pronounced than at lower relative densities for a specimen of given particle shape. Gradation appeared to have an effect for the moist specimens, although a defined trend was not observed. The moist specimens exhibited greater resistance penetration than did the oven dry specimens. Scale effects are discussed and considerations for future full-scale testing are identified.
Review of Specific Local Fenestration Units, Building Envelope Interface Practices, and Materials Compared to ASTM E 2112, Current Acceptance Criteria, and Evaluation Practices
Authors: Ackerman DS
Published: March 2009

1. Variations in physical installation environments

a. Weather variations in Washington

b. Types of construction and materials used

c. Weather impact on interface materials and exposure periods

d. Installation practices during varying conditions

2. Installation of windows and flashing in single and multifamily projects in the Northwest

a. Divergence of methods between locations and type of construction

b. Agency requirements and inspections

c. Architect construction plan specifications

d. Practice compared to window manufacturers and E2112 specifications

e. Common Installation Problems Caused By Window Installers

f. Practical considerations, standards vs. the real world

f. Window manufacturer's instruction, guidance and training

h. Flashing observations encountered in the development of a new product

3. Consideration of current Acceptance Criteria and Evaluation Reports
The Effect of Hydrogen on the Ductile Properties of Irradiated Pressure Vessel Steels
Authors: Brinkman CR , Beeston JM
Published: March 2009

The influence of hydrogen on the mechanical properties (ductility, fracture strength, and tendency towards delayed failure) was investigated for several irradiated pressure vessel steels. Included were ASTM A302B, A542, and HY-80 steel irradiated at fluences from 8×1018 to 4×1020 n/cm2, E > 1 MeV. Specimens from plate sections of these steels which had been quenched and tempered and some from A542 which were given prestrain and heat treatment modifications were prepared and tested. The effects of strength level from irradiation, heat treatment, and microstructure were thus determined. Reductions in ductility and true fracture strength occurred with increasing hydrogen content but were not extensive at strength levels less than 180 ksi in specimens containing 1 to 2 ppm hydrogen. This concentration, however, produced a marked effect on the ductile properties when the strength level was increased by irradiation hardening or heat treatment beyond this threshold range. Irradiation hardening increased the magnitude of the decrease in notched strength resulting from a given hydrogen content in all of the steels and conditions tested. Hydrogen induced delayed failure, however, did not occur to any large extent in HY-80, A302B, and A542 steel in the normal quenched and tempered condition even after irradiation to fluences in excess of 1020 n/cm2, E > 1 MeV, and hydrogen concentrations of up to 4 ppm.
Evaluation of the Embrittlement of Pressure Vessel Steels Irradiated in JPDR
Authors: Kawasaki M , Fujimura T , Suzuki K , Namatame H , Kawasaki M
Published: March 2009

Three surveillance programs of the JPDR pressure vessel have been performed to date. From the assessment of both the shift of NDT temperature and the reduction of upper shelf energy in the pressure vessel steel due to irradiation, it was concluded that the pressure vessel could be used with safety for about ten years at equivalent full power (45 MWt) operation.

A reference test was also performed on two potential steels for pressure vessel use, namely a Mn-Mo-0.4∼0.7Ni steel (A533B Class 1) and a 2 1/4Cr1Mo (A542 Class 1) steel, following the completion of the surveillance test. The latter steel was found to be much less sensitive to irradiation than the former. The weld metal and heat affected zone are somewhat more sensitive to irradiation than the base metal for the 2 1/4Cr-1Mo steel submerged arc weldment.
Axial Fatigue of Irradiated Stainless Steels Tested at Elevated Temperatures
Authors: Beeston JM , Brinkman CR
Published: March 2009

Uniaxial fatigue properties from tests at 400, 500, 600, and 700 C on Type 304, 304L (Ti modified), and 316 stainless steel specimens irradiated at 450 C in sodium and 750 C in argon at fluences of 0.03 to 9.3×1021 n/cm2, E>0.1 MeV, are given and compared with control specimens. Material was tested in the annealed, cold-worked, and chilled-swaged-tempered condition, while primary controls received a pretest anneal of 1500 h at 750 C. The data at 400, 500, and 600 C are compared with proposed design curves for 18-8 steels. Some data on microstructural changes due to irradiation are given. A reduction in the fatigue life by a factor of less than 2.5 was found in the annealed material, which was attributed to irradiation damage. A beneficial effect on fatigue life of pretreatment by swaging was found after irradiation at 450 and 750 C for 2550 h.
Effect of Irradiation on the Mechanical Properties of 19-9DL Alloy
Authors: Lowe AL , Baroch CJ
Published: March 2009

Austenitic stainless steels, which are used extensively in water cooled nuclear reactors, are presently being considered for use in fast reactors; however, these steels are susceptible to irradiation embrittlement and irradiation induced swelling. The modified austenitic stainless steel 19-9DL alloy, on the other hand, exhibits good creep strength at high temperatures. Babcock & Wilcox conducted an exploratory program to determine the effects of irradiation on 19-9DL alloy at temperatures of 55 C (130 F), 343 C (650 F), and 413 C (775 F). The maximum fluence in this program (9.2×1020 n/cm2, E>1 MeV) was too low to prove the suitability of the alloy's potential for fast reactor applications but did show that additional evaluation of the alloy for fast reactors was warranted. The results indicate that the alloy is suitable for use in thermal reactors, since the ductility at 413 C was greater than 10 percent at a fluence approaching 1×1021 n/cm2, E>1 MeV.
Strengthening Mechanisms in Fatigue
Authors: Feltner CE , Beardmore P
Published: March 2009

The present state of knowledge of the role of metallurgical structure in the achievement of high fatigue resistance is critically examined and the application of such knowledge is discussed. At the present time resistance to fatigue is best characterized in terms of phenomenological parameters such as the cyclic strain hardening exponent. The effect of changes in metallurgical structure on these parameters is then the best index of the microstructural effects. The importance of distinguishing between resistance to repeated stresses as opposed to resistance to repeated plastic strains is emphasized, since the metallurgical means of achieving the required resistance can be radically different. The fatigue process is discussed in terms of plastic deformation, crack initiation, and crack propagation mechanisms, and the techniques by which these processes can be modified are detailed and related to the phenomenological parameters. Finally, a set of basic guidelines for achievement of high fatigue resistance by metallurgical means is outlined.
The Fatigue Strength of Nickel-Base Superalloys
Authors: Gell M , Leverant GR , Wells CH
Published: March 2009

The service lives of nickel-base superalloy components in gas turbine engines are frequently limited by their fatigue properties. This paper reviews what is known about the fatigue behavior of nickel-base superalloys and suggests methods for improving their properties. Low-temperature crack initiation occurs preferentially at microstructural defects such as pores and brittle phases in cast materials and at defects such as brittle phases and annealing twin boundaries in wrought materials. The brittle phases may contain inherent cracks or be cracked during working operations or service exposures. Plastic deformation at low temperatures is concentrated in coarse planar bands, and as a result matrix cracking is predominantly transgranular and crystallographic. Techniques are discussed for increasing the low-temperature fatigue properties by minimizing the role of microstructural defects and achieving a more homogeneous distribution of deformation.

At elevated temperatures, intergranular cracking predominates and methods are discussed for improving fatigue properties through grain size control, the use of columnar-grained and single-crystal materials, and the application of oxidation-resistant and fatigue-resistant coatings.
Thermomechanical Processing and Fatigue of Aluminum Alloys
Authors: Ostermann FG , Reimann WH
Published: March 2009

A review is made of the available information on thermomechanical processing of aluminum alloys, especially with respect to their fatigue behavior. An attempt is made to evaluate from the scarce and sometimes contradictory experimental evidence the possibility of improving the fatigue resistance of high-strength aluminum alloys by these treatments. To do so, it is also necessary to review the important microstructural features and deformation characteristics of these alloys, which seem to control the various stages of fatigue, and which may be influenced by the thermomechanical treatments. The discussion is limited to thermomechanical treatments subsequent to solution annealing. It is concluded that suitable processing offers the advantage of improving both strength and ductility in Al-Cu and Al-Zn-Mg-Cu alloys. If the effects of inclusions can be minimized, significant benefits are possible in fatigue, at least in Stage I crack resistance, by thermomechanical processing.
Surface Treatments for Fatigue Strengthening
Authors: Benson DK
Published: March 2009

Three broad categories of surface treatments are considered: discrete coatings, surface diffusion treatments, and thermomechanical treatments. From the standpoints of reliability and versatility, surface diffusion treatments appear to be best suited for fatigue strengthening. A surface treatment which truly strengthens must not, on the other hand, increase the susceptibility to other forms of damage such as wear, corrosion, and oxidation. It is shown that surface diffusion coatings have the potential capability of providing an increased resistance to all of these forms of damage. Some guidelines are developed for the design of such all-around protective treatments.
Fatigue Life Improvement Through Stress Coining Methods
Authors: Speakman ER
Published: March 2009

The use of a quick and economical new process, stress coining, results in an aircraft structure with a more balanced fatigue strength than was previously possible. Basically, the stress coining procedure, a proprietary method of the Douglas Aircraft Co., involves controlling the yielding of material inside holes and in the material surrounding holes and slots. Stress coining induces residual compressive stresses that offset load-induced tensile stresses concentrated around these load-carrying areas. The procedure can be used in highly stressed areas to increase fatigue life and resistance to stress corrosion of structural members. Salvage rework by reaming, stress coining, and installing an oversize fastener increases the remaining fatigue life to approach that of a virgin stress-coined structure. Fatigue life of test specimens for various aircraft has been improved by a factor of approximately four.
Improvement in the Fatigue Strength of Notched Bars by Compressive Self-stresses
Authors: Gerber TL , Fuchs HO
Published: March 2009

In this investigation the long-life fatigue strength of sharply notched steel bars was improved by as much as 300 percent with the introduction of compressive self-stresses. Compressive self-stresses were produced by an axial tensile preload. Quantitative estimates of this improvement were made as a function of preload using suitable failure criteria and an analytical estimate of the stable self-stress distribution. The importance of the distribution in depth is demonstrated. A criterion for predicting crack propagation is improved and clarified.
Effect of Temperature and Pressure on Cavitation Damage in Sodium
Authors: Young SG , Johnston JR
Published: March 2009

Three materials with widely different mechanical properties, L-605, Stellite 6B, and AISI 316 stainless steel were subjected to accelerated cavitation damage in sodium at 800 F (427 C). L-605 was tested also at 400 F (204 C) and 1200 F (649 C). A magnetostrictive vibratory apparatus was used. Argon was introduced over the liquid sodium to maintain pressures ranging from 1 to 4 atm (1 to 4 × 105 N/m2). Cavitation damage was determined by volume loss measurements, and metallographic studies were made.

It was found that increasing pressure significantly increased cavitation damage to all materials at all temperatures tested. When the volume-loss-rate data were normalized to consider only the heavily damaged area of the specimens, the average volume loss rate increased as a power function of pressure (at pressures above approximately 2 atm (2 × 105 N/m2)). This result of increasing damage with increasing pressure implies that, in fluid systems where cavitation occurs in high pressure regions, damage to components may be much greater than would be expected normally from cavitation tests conducted at atmospheric pressure. L-605, the one material tested at all three temperatures and all four pressures, exhibited greater damage at 800 F (427 C) than at 400 F (204 C), or 1200 F (649 C) at all pressures.

At 800 F (427 C) the single temperature at which all materials were tested over the entire range of pressures, the relative ranking of the materials with respect to resistance to cavitation damage was the same regardless of pressure. In order of increasing damage, it was Stellite 6B, L-605, and AISI 316 stainless steel. This result, together with the fact that the damage rate increased with increasing pressure, suggests that laboratory cavitation damage testing can be greatly accelerated by conducting such tests at higher pressures.

Metallographic examination of axially sectioned specimens of all the materials tested at 800 F (427 C) revealed severe undercutting of the surface and transgranular cracking. Surface deformation was indicated by the appearance of slip bands in all materials after testing at 800 F (427 C). Stellite 6B showed extensive cracking of carbides beneath the surface, and L-605 exhibited some bending of twins near the surace.
Some Observations on Erosion by Cavitation and Impingement
Authors: Gould GC
Published: March 2009

This is a progress report discussing the selection of cavitation induced by ultrasonic vibration as a test for erosion resistance of metallic materials. The resistance of many metallic materials is measured and reported. In addition, the influence of vibration amplitude and material properties is discussed, and, further, electron micrography is applied to study the early stages of erosion.
Toward Quantitative Prediction of Liquid Impact Erosion
Authors: Heymann FJ
Published: March 2009

There still exists no objective measurement of the erosion resistance of a material, nor a theory for predicting the material loss to be expected under given service conditions, based on any generally accepted hypotheses concerning the erosion damage mechanisms. This paper presents an approach which does not presuppose any specific mechanisms but rather is based on empirical data and dimensional considerations.

First, a “normalized erosion resistance” (Ne) of a material is defined which allows direct comparison of many different test results, including cavitation tests, and provides a quantitative measure of erosion resistance even though that is not yet a physically understood property. One finds that the values of Ne for metals vary from about 0.03 for soft aluminum to about 60 for some stellites and hard tool steels; total range of about 2000:1. Neither hardness nor strain energy or other independent parameters prove to be reliable indexes to erosion resistance.

In order to develop a quantitative formula for predicting impingement erosion, the “rationalized erosion rate” (Re) is defined as the ratio of volumetric material loss rate to the volume rate of liquid impingement. Previous studies have suggested that this quantity should be proportional approximately to the fifth power of impact velocity.

Plotting NeRe for a number of experimental results versus normal impact velocity Vo (m/s) confirms the power law and yields two approximate relationships: NeRe = (Vo/2550)5.05 for impact against droplets, and NeRe = (Vo/2920)4.37 for impact against cylindrical jets.

Some of the physical hypotheses which have been proposed for the prediction of erosion damage, particularly those based upon the concept of energy transfer from the impinging liquid to the eroding surface, are examined for consistency with these findings, and tests with different liquids are found to be necessary to resolve this question.
Experimental and Analytical Investigations on Liquid Impact Erosion
Authors: Thiruvengadam A , Rudy SL , Gunasekaran M
Published: March 2009

Experimental and analytical research on erosion of 1100-0 aluminum, 316 stainless steel, commercially pure annealed nickel, and 6A1-4V titanium (annealed) is summarized. The erosion is caused by the multiple impacts of a water jet in a rotating disk facility. The relationship between the velocity of impact and the number of impacts at which visible indentations were observed is compared with the high-frequency fatigue strength of these materials. The experimentally observed rates of erosion are compared with a recently developed theory of erosion. The fatigue life distribution curves also are included. The peak rate of erosion varies approximately as the fifth power of the velocity, whereas the time at which the peak rate is observed varies as the one-fifth power. The cavitation erosion strength and liquid impact erosion strengths of these materials also are compared.
The Effect of Cement Fineness on Concrete
Authors: Higginson EC
Published: March 2009

Bureau of Reclamation experience over the last 35 years, both in field work and laboratory studies, has demonstrated many ways in which cement fineness affects concrete properties. Studies include observations with both air-entrained and nonair-entrained concrete. All results are compared on the basis of fineness reported by the Blaine method. Properties of concrete for which data related to the effect of fineness are presented include: bleeding, water requirement, workability, compressive strength, modulus of elasticity, and deterioration caused by freezing and thawing. In general, it has been found over the years that cements meeting the requirements of the Federal specifications for portland cement have not created concreting problems which could be significantly influenced by changes in cement fineness.
Cumulative Damage Analysis in Structural Fatigue
Authors: Impellizzeri LF
Published: March 2009

The influence of residual stress on fatigue is studied using electron microscopy on fracture surfaces of specimens tested under spectrum loading. The level of residual stress that exists at the point of stress concentration is shown to be one of the parameters affecting striation spacing. A review of numerous variable amplitude test results generated by government agencies and aerospace companies further suggests that a straightforward technique quantitatively defining the effect of continually changing residual stress patterns should provide a reliable tool for predicting cumulative damage in fatigue. The two major difficulties relating to the utilization of residual stress considerations in a cumulative damage rule are: (a) determining the level of residual stress existing at the notch root; and (b) computing its effect on N, cycles to failure. A cumulative damage rule including the developments in (a) and (b) above is presented. Essentially, the rule involves the use of conventional Σn/N computations, except the selection of a value for N is affected by the levels and variations of residual stress existing at a discontinuity. Loading parameters that affect fatigue-life predictions using the cumulative damage rule include peak load level, load ratio, block size, and load-level sequence. Typical laboratory spectrum-test results that are investigated include the NASA gust spectrum. Specimens tested to this spectrum sustained 9 blocks to failure in a low-high sequence, 26 blocks in a high-low sequence, and 20 blocks in a high-low-high-sequence. Corresponding life predictions are 10.9, 25.2, and 19.6 blocks to failure.
Effects of Notches and Saltwater Corrosion on the Flexural Fatigue Behavior of High-Strength Structural Alloys
Authors: Schwab RC , Czyryca EJ
Published: March 2009

The effects of mechanical notches and saltwater corrosion on the flexural fatigue behavior of seven high-strength structural alloys were investigated over a broad life range of 1,000 to 100 million cycles. The seven alloys (three ferrous, three titanium, and one aluminum) had approximately the same ratio of yield strength to density.

Results showed that notches were most damaging in the high-cycle life range, and that only titanium alloys exhibit a fatigue limit when subjected to corrosion fatigue. When compared on the basis of fatigue strength in air, the high-strength steels are superior over the entire life range. If, however, comparisons are made on the basis of ratio of fatigue strength to density, all seven alloys are approximately equal. The comparison of fatigue strength and ratio of fatigue strength to density over the broad life range for corrosion fatigue shows the titanium alloys to be superior at intermediate and long lives.
The Influence of Salt Water on Fatigue-Crack Growth in High-Strength Structural Steels
Authors: Crooker TW , Lange EA
Published: March 2009

Fatigue-crack growth is a potential failure mechanism that can be strongly influenced by a salt-water environment. This paper discusses fatigue-crack-propagation studies performed on three high-strength structural steels: 9Ni-4Co-0.25C, 12Ni 180-grade maraging, and 18Ni 200-grade maraging. Each steel underwent a program of fatigue cycling in two environments, a “dry” environment consisting of ambient room air and a “wet” environment consisting of 3.5 percent NaCl salt water. Relationships for fatigue-crack-growth rates as a function of the fracture mechanics stress-intensity factor (K) were obtained experimentally for each steel in both environments. The engineering significance of these relationships is presented in terms of stress levels and flaw sizes relevant to the steels under investigation. The results of this work indicate that, in an air environment, the fatigue-crack-growth rate correlates with the stress-intensity-factor range according to the power-law relationship, da/dN = C (ΔK)m. Fatigue-crack growth in each of the steels was accelerated by the salt-water environment. However, the environmental response varied significantly, depending upon the material and the ΔK level. The lower-toughness steel was less affected by environment, and environmental effects in all the steels diminished with increasing ΔK levels. No correlation was observed between fatigue-crack-growth behavior in the salt-water environment and the stress-corrosion-cracking parameter (K Iscc) obtained on the same materials.
The Charpy Impact Test—Its Accuracy and Factors Affecting Test Results
Authors: Fahey NH
Published: March 2009

The Army Materials and Mechanics Research Center, AMMRC, (formerly Watertown Arsenal Laboratories) has managed a program for many years on the certification of Charpy impact machines. During this period, approximately 200 machines have been evaluated annually.

This paper is a compilation of the findings of these certification tests. What is evident is that each model machine possesses its own characteristic weaknesses which, unless controlled, can easily result in erroneously high test values. It is estimated that approximately half of the machines in use today are producing values well in excess of the limits set in Army specifications; that is, plus or minus 5 percent or 1.0 ft∙lb, whichever is the greater. Since most discrepancies either slow down the pendulum or result in absorptional losses, the value recorded includes energy not expended in fracturing the specimen, thus creating a false sense of security for the investigator or design engineer.
Investigation of Transition Temperature Tests for Line Pipe Materials
Authors: Norris EB , Wylie RD
Published: March 2009

The American Petroleum Institute currently provides standards for the evaluation of welded line pipe with the drop-weight tear test. A two-phase program investigating the drop-weight tear test specimen geometry and the relationship between transition temperatures determined by various brittle fracture tests is described. The fracture appearance transition temperature was found to be affected by specimen thickness and metallurgical conditions and in addition was distinctly higher than transition temperatures determined by four other brittle fracture tests.
Correlations Between KIc and Charpy V-Notch Test Results in the Transition-Temperature Range
Authors: Barsom JM , Rolfe ST
Published: March 2009

Charpy V-notch (CVN) impact-test results are used widely in various toughness specifications even though the energy absorption values cannot be related directly to structural design. Conversely, KIc, the plane-strain stress-intensity factor at onset of unstable crack growth, can be related to structural design, but KIc test results usually are not used in toughness specifications. To the designer, however, KIc values are more useful than CVN values. An investigation, therefore, was conducted to determine whether correlations could be developed between KIc and CVN test results in the transition-temperature range to assist both the materials engineer and the structural designer.

The results showed that various correlations do exist between KIc and CVN test results in the transition-temperature range. Static KIc values were correlated with the energy absorptions determined with slow-bend fatigue-cracked CVN specimens, and dynamic KIc values were correlated with the energy absorptions determined with dynamic fatigue-cracked CVN specimens. Empirical correlations also were developed between the results of slow-bend KIc tests and the results of standard CVN impact tests for the transition-temperature region as well as the upper-shelf region. Furthermore, the results show that slow-bend and impact CVN data can be used to predict the effects of dynamic loading on KIc values.

In general, the results of this investigation have shown that correlations between KIc and CVN test results do exist, and that these correlations can be used to estimate KIc values as well as the effect of loading rate on KIc from CVN test results.
Development of a Pendulum-Type Dynamic Tear-Test Machine
Authors: Franz WF
Published: March 2009

New American Petroleum Institute specifications for line-pipe steels has prompted an evaluation of testing machines available to perform the Battelle drop-weight tear test (DWTT). This evaluation indicated a need for a machine of new design that would be safe, accurate, require little maintenance, and be acceptable as an industry-wide standard. The machine preferred was the pendulum-type machine rather than a vertical drop-weight type because of low maintenance, operator comfort, and accuracy of fracture-energy determination. Therefore, a pendulum-type machine was designed and built by the U.S. Steel Applied Research Laboratory. This new machine has a 6300-ft∙lb capacity and is capable of testing both the Battelle 12-in.-long DWTT specimen for line-pipe steels and the Naval Research Laboratory 18-in.-long dynamic-tear-test specimen for ship-plate steels. The pendulum head and anvil are designed to prevent interference between the broken sections of the test specimen and the pendulum after impact. The frame structure is designed to prevent vibration within the structure. The machine is operated by compressed air-mechanical devices, and the control circuit is designed to provide fail-safe operation by one man. Performance testing, strain analysis, and high-speed photography indicate that this machine fulfills the desired design goals. In the interest of standardization, the design is being proposed for industry-wide use.
Some Uses of Color in Metallography
Authors: Yakowitz H
Published: March 2009

The application of various methods for using color in metallography is outlined. The methods include plane and circularly polarized light, color etching, and color separation photography. Instruments used to obtain subjects for the color metallography examples shown in this paper include the optical microscope, the electron probe microanalyzer, the scanning electron microscope, and the transmission electron microscope. A brief discussion of color films is given. The technique used to obtain color photographs is given in detail for each aspect of color metallography discussed.
Replicating Techniques for Electron Fractography
Authors: Pelloux RM
Published: March 2009

The different replicating techniques used in electron fractography are reviewed briefly and general guidelines are given to judge the advantages and difficulties of each technique.
Advances in X-ray Metallography
Authors: Newkirk JB
Published: March 2009

X-ray metallography, as defined for this review, consists of the application of X-rays to the microstructural characterization of solids. Basic crystal structure analysis is excluded, though the identification of phases whose crystal structures are known is not: the subject is briefly reviewed, using examples taken mostly from recently published works. The principles and typical applications of X-ray diffraction topography are emphasized. Other methods to which specific references are made include microradiography, macrostrain measurement, Kossel pattern analysis, and applications of long wavelength X-ray analysis.
Slow-Bend KIc Testing of Medium-Strength High-Toughness Steels
Authors: Rolfe ST , Novak SR
Published: March 2009

Linear-elastic fracture mechanics (LEFM) has been used extensively to analyze the fracture behavior of steels having yield strengths greater than 200 ksi. Although theoretically LEFM can be used to analyze the behavior of all steels, it has not been used extensively to analyze the behavior of medium-strength (and lower-strength) high-toughness steels, because large plastic-zone sizes develop prior to fracture of these steels and test results are therefore difficult to analyze. Therefore, to establish the limitations of the LEFM approach to the analysis of medium-strength steels, a series of slow-bend KIc tests were conducted on various steels, with different levels of toughness.

The present paper describes the test procedures and analyses used in slow-bend KIc tests of steels having yield strengths from 110 to 246 ksi and Charpy V-notch impact energy absorption (+80 F) in the range 16 to 89 ft • lb. The range of KIc values for various pop-in criteria is presented as well as a discussion of the various factors affecting the slow-bend KIc testing of medium-strength high-toughness steels.

The results indicate that LEFM can be used to analyze the fracture behavior of medium-strength high-toughness steels. KIc values ranging from 87 to 246 ksi in. were obtained for the eleven steels investigated. Although the specimen sizes tested generally 2 in. thick) did not satisfy completely the recommended ASTM Committee E-24 size requirements (in some cases, the suggested sepcimen thicknesses were greater than 6 in.), the KIc values are considered to be representative on the basis of general strength and Charpy V-notch toughness levels and expected service performance. Therefore, the measured KIc values are estimated to be reliable for general engineering use, although some of the specimen sizes did not satisfy the current ASTM Committee E-24 requirements completely.

When KIc and Charpy V-notch energy-absorption values were normalized on the basis of yield strength, an empirical correlation was established over a wide range of yield strengths. Although such a correlation increases the confidence in both types of approaches to fracture analysis, the use of Charpy tests to predict KIc values is not recommended until additional test and service experience is obtained.
Commentary on Present Practice
Authors: Brown WF , Srawley JE
Published: March 2009

Emphasis on specimen size requirements and attempts to correlate KIc with simpler mechanical test results because these are areas of considerable controversy among those engaged in plane strain fracture toughness testing are presented. Problem areas in connection with plane strain fracture toughness testing indicate that the Tentative Method of Test for Plane Strain Fracture Toughness of Metallic Materials (E 399-70 T) may need revision before being advanced to a Standard and that additional experimental data are needed in order to make a judgment concerning the need for revision.
Effects of Environment and Complex Load History on Fatigue Life
Authors: Rosenfeld MS
Published: March 2009

Description

The Symposium on Effects of Environment and Complex Load History on Fatigue Life was presented at the Fall Meeting of ASTM held in Atlanta, Ga., 29 September–4 October, 1968. Committee E09 on Fatigue sponsored the symposium. M. S. Rosenfeld, U.S. Naval Air Engineering Center, was responsible for the session on Cumulative Damage and Life Estimation. S. R. Swanson, MTS Systems, was responsible for the session on Fatigue Under Random Loads. D. W. Hoeppner, Battelle Memorial Institute and R. I. Stephens, University of Iowa, were responsible for the two sessions on Influence of Environment on Fatigue.