bluuebunny/crossref_metadata_2025 huggingface dataset:
Ptch1is required locally for mammary gland morphogenesis and systemically for ductal elongation
Authors: Moraes Ricardo C. , Chang Hong , Harrington Nikesha , Landua John D. , Prigge Jonathan T. , Lane Timothy F. , Wainwright Brandon J. , Hamel Paul A. , Lewis Michael T.
Published: March 2009

Systemic hormones and local growth factor-mediated tissue interactions are essential for mammary gland development. Using phenotypic and transplantation analyses of mice carrying the mesenchymal dysplasia (mes) allele of patched 1 (Ptch1mes), we found that Ptch1mes homozygosity led to either complete failure of gland development, failure of post-pubertal ductal elongation, or delayed growth with ductal dysplasia. All ductal phenotypes could be present in the same animal. Whole gland and epithelial fragment transplantation each yielded unique morphological defects indicating both epithelial and stromal functions for Ptch1. However, ductal elongation was rescued in all cases,suggesting an additional systemic function. Epithelial function was confirmed using a conditional null Ptch1 allele via MMTV-Cre-mediated disruption. In Ptch1mes homozygotes, failure of ductal elongation correlated with diminished estrogen and progesterone receptor expression, but could not be rescued by exogenous ovarian hormone treatment. By contrast,pituitary isografts were able to rescue the ductal elongation phenotype. Thus, Ptch1 functions in the mammary epithelium and stroma to regulate ductal morphogenesis, and in the pituitary to regulate ductal elongation and ovarian hormone responsiveness.
Application of faceted classification in the support of manufacturing process selection
Authors: Giess M , McMahon C , Booker J D , Stewart D
Published: March 2009

Engineering designers are required to consider many factors concurrently when evolving a design, one such factor being the manufacturing process by which the product will be realized. The selection of such a process involves filtering available processes according to the current design situation, and providing detailed information describing this subset of processes such that the engineer may further refine the design. The approach described in this paper allows an engineer to browse documented manufacturing process information through a faceted classification (FC) system. Where traditional hierarchical classifications are notably viewpoint-dependent, an FC essentially comprises concurrent classification schemes (facets). A designer may browse within and across any combination of facets of interest and make selections at any given level of granularity. The use of a classification scheme provides a degree of abstraction, useful when certain process capabilities may not be directly expressible as parameters. A software environment, Waypoint, has been developed which assists in the construction and population of the faceted scheme, supports the designer in browsing, and through which relevant documentation may be identified and retrieved. The approach is demonstrated upon process descriptions obtained from an engineering textbook, although it may be applied to any given document corpus.
Configuration of dynamic value added networks
Authors: Lanza G , Ude J
Published: March 2009

Globally operating companies face the challenge of an optimal and efficient configuration of their value added network. The participating sites, partners, and suppliers have to be selected according to their specific capabilities. Thereby the configuration has to respect not only the actual status but also the different dynamic influences of the nodes of the network themselves and also of the connections between them. This paper presents an approach for the configuration of global value added networks using business capabilities with special consideration of the ramp-up behaviour of the single elements. A simulation implemented in Tecnomatix Plant Simulation™ serves as a validation for the theoretic approach.
Research Note—Wine Journalism—Marketing or Consumers' Guide?
Authors: Horverak Øyvind
Published: March 2009

This article explores some aspects of wine journalism in Norwegian newspapers. Two issues are discussed: First, are wine sales influenced by wine journalists' reviews? Second, do experts agree on what makes a good wine buy? The results show that wine sales are indeed significantly influenced by the judgements of wine critics; a 10% rise in newspapers' scores in Norway was accompanied by an average increase of 16%–18% in sales figures for table wines. The effect of wine reviews varied somewhat from newspaper to newspaper. It proved difficult to establish criteria for a good wine buy that are objective and independent of the person making the judgement. The journalists gave no unanimous recommendation of good wine buys to the consumers; the same wine could get good reviews in some papers and might well receive run-of-the-mill reviews in others. However, a majority of the reviewers seemed to agree in the ranking of most of the wines, even if the absolute value of the scores differed.
Neuroleptic Malignant Syndrome Secondary to Quetiapine
Authors: Gortney Justine Schuller , Fagan Alexandria , Kissack Julie Cold
Published: March 2009

Objective:

To report a case of neuroleptic malignant syndrome (NMS) secondary to quetiapine in which the patient developed extrapyramidal symptoms (EPS).

Case Summary:

A 34-year-old male with a history of severe brain damage, mental retardation, and seizures was admitted to the hospital with changes in mental status, development of tremors, and a temperature of 39.9 °C. Initial differentia) diagnoses included seizure, aspiration, stroke, and infection. Once these were excluded, NMS was considered. The patient exhibited other characteristics of NMS during hospitalization, including lead pipe rigidity, tachycardia, and high creatine kinase level (up to 12,654 IU/L). Drug therapy on presentation included quetiapine 200 mg 3 times per day, guanfacine 2 mg/day. carbamazepine 400 mg every 12 hours, valproic acid 500 mg twice daily, and lorazepam 2 mg (unknown schedule). He reportedly had received these medications for at least a month before admission. On hospital day 2, quetiapine was discontinued. The patient received traditional treatment (or NMS, which included bromocriptine, dantrolene, intravenous fluids, and supportive care. The NMS resolved in 7 days.

Discussion:

In cases of NMS, clinicians previously believed that the risk for developing severe adverse effects such as EPS was lower with atypical versus typical antipsychotics. We identified 13 cases of NMS secondary to quetiapine in the literature via a search of MEDLINE/PubMed (1950–2008), and Iowa Drug Information Service (1966–2008). Seventy-five percent of previous reports of NMS secondary to quetiapine had reactions that included EPS, Common patient characteristics in our report and others included male sex, history of mental retardation, and treatment modalities used in NMS. Unique characteristics in this case included length of therapy without dosage change or titration and no known history of drug-related EPS. The Naranjo probability scale indicated a probable relationship between the development of NMS and quetiapine.

Conclusions:

NMS with associated EPS has been previously associated with quetiapine. Clinicians should be aware that NMS with EPS can occur with quetiapine at steady state doses without recent dosage adjustments or titration.
Creep Embrittlement Susceptibility and Creep Crack Growth Behavior in Low-Alloy Steels: An Assessment of the Effects of Residual Impurity Elements and Postweld Heat Treatment Condition on Creep Ductility and Crack Growth
Authors: Konosu S , Maeda K
Published: March 2009

Creep embrittlement at 550C in the coarse grain region of the heat-affected zone (HAZ) of 1Cr-Mo steel was investigated. As a result, the effects of impurity elements and postweld heat treatment (PWHT) on such creep embrittlement and crack growth has been clarified. Creep embrittlement is caused by the nucleation of intergranular cavities at the prioraustenite grain boundary of the HAZ. Likewise, creep crack propagation is caused by the nucleation and linking up of intergranular cavities which precede the further growth of the main crack. The remaining creep crack growth life was predicted by a computer simulation of an actual reactor.
Measurement of Dynamic Fracture Toughness of Ductile Materials
Authors: Hackett EM , Joyce JA , Shih CF
Published: March 2009

The primary objective of this study was to demonstrate the applicability of a J-based approach to fracture characterization of ductile alloys subjected to dynamic loading. Three-point-bend [SE(B)] fracture specimens of a high-strength steel were subjected to impact loading in a drop tower, and appropriate strains and displacements were measured to allow estimation of J. A finite element analysis of these experiments was conducted to evaluate the applicability of a J-based fracture characterization scheme and to provide guidance for the experimental measurements. The concept of a transition time was introduced to provide an estimate of the time during which the controlling crack-tip field [Hutchinson-Rice-Rosengren (HRR) field] stabilizes. The paper demonstrates that for fracture times greater than the transition time, J can be accurately evaluated by the quasi-static deep-crack formulation. For the case of the steel SE(B) specimen geometry used for this study, the transition time was approximately 300 s. The finite-element analysis indicated that the net moment carried by the remaining ligament of the specimen could be evaluated by measurements of the flexural and stresses at the quarter-span position on the SE(B) specimen. This was verified experimentally in drop tower experiments utilizing strain gages at the quarter-span position. These results were found to compare well with a load estimation scheme based on a full bridge of strain gages attached to the tension and compression surfaces of the SE(B) specimen. The load accuracy obtained using the full bridge was also found to be insensitive to crack extension and plasticity at the crack tip. Methods of determining the crack initiation point in these dynamic experiments were evaluated. It was found that the double capacitance crack-opening displacement (COD) gage used in the experiments provides an accurate estimate of the crack initiation point.
Fracture Toughness Testing of Polyethylene Pipe Materials
Authors: Jones RE , Bradley WL
Published: March 2009

Multiple-specimen J-integral tests, which are defined in the ASTM Test for JIc, A Measure of Fracture Toughness (E 813-81), have been conducted on side-grooved compact tension specimens of medium- and high-density polyethylene. The specimens were precracked with a razor blade, as has been common practice to date, or were fatigue precracked. Tests were performed over a 50 range of crosshead rates in the quasi-static regime. Results indicated that the razor notching gives a J-R curve which is significantly higher than that obtained using fatigue precracked specimens. A significant variation in the J-R curve was noted for changes in the displacement rate due to the viscoelastic character of the polyethylene. The orientation of the specimens, which were cut from actual pipe, was found to have a significant effect on the fracture toughness. The fracture toughness results were correlated with fractographic results, and the behavior of side-grooved and non-side-grooved specimens was compared.
Polysulfide Rubber
Authors: Peterson EA , Pozniak BW , Smith DJ , Yazujian AD
Published: March 2009

The chemistry of Thiokol LP® liquid polysulfide polymers and their ambient temperature vulcanization to rubbery products is presented. Compounding, chemical and physical properties, testing, and specification data for polysulfide building sealants are also included.

Application techniques, joint design, and recommended practices for the installation of polysulfide sealants in building, heavy construction, and highway areas are discussed. The aforementioned cover expansion joints, glazing, curtain walls, canals, decks, and highways.
A Review of Sealant Specifications Throughout the World
Authors: Panek J
Published: March 2009

This paper covers the development of sealant specifications starting from the three earliest specifications, namely; the ASA A116.1 (1960), and the two Federal Specifications TT-S-00227 and TT-S-00230 which served as models for specifications developed throughout the world. Specifications from the United States, Canada, Germany, Great Britain, Norway, Japan, and Australia are compared in their performance requirements. Comments are given on the severity of the various specifications. This paper covers developments through 1975.
Back-Up Materials
Authors: Balliet KE , Panek J
Published: March 2009

This paper gives an early history of various back-up materials, and elaborates on early sealant failures which were due in part to improper joint design. Satisfactory joint sealant performance therefore depended on proper selection of back-up materials and proper joint design. The authors elaborate on the latest technology. General requirements and proposed tests for back-up materials from ASTM Subcommittee C24.40 are given.
VTOL Aircraft
Authors: Salkind MJ
Published: March 2009

Fibrous composites offer significant potential for structural improvement in VTOL (vertical take off and landing) aircraft. In addition to the potential for light weight fuselage structures, composites offer the unique capability of providing dynamic tuning of the fuselage. Composites provide substantial potential for helicopter rotor blades because of improved fatigue capability, good damage tolerance, and ability to be molded in complex aerodynamic configurations.

This chapter summarizes the major design considerations in VTOL aircraft and reviews composite hardware which has been developed to date.
Plane Stress Fracture Testing Using Center-Cracked Panels
Authors: Carman CM
Published: March 2009

Three experimental techniques for developing the crack resistance curve and plane stress fracture toughness using center cracked panels are reviewed. One technique involving a plasticity characterization based on the crack opening stretch is discussed in detail.

Experimental data for a variety of materials and thicknesses are presented which show the equivalence of the various methods for determining the crack resistance curve.
A Note on the Use of a Simple Technique for Failure Prediction Using Resistance Curves
Authors: Creager M
Published: March 2009

The use of resistance curves in the prediction of catastrophic failure in a structure normally requires the determination of the point of tangency between the resistance curve and the applied stress intensity versus crack length curve evaluated for the failure stress. Since the failure stress is unknown a priori a number of iterations or interpolations or both are necessary. This is often a cumbersome task. A simple procedure utilizing a transparency is presented which enables the critical stress intensity factor based on final crack length, the critical stress intensity factor based on initial crack length, and the failure stress to be found directly without iteration or interpolation.
Rheology of Asphalt Cements at 60 C (140 F)
Authors: Schweyer HE , Moore JP , Ling JK
Published: March 2009

Studies on the viscosity of 18 asphalts at 60 C (140 F) showed that the result depends upon the apparatus and procedure used. The Florida capillary method at constant shear rate gives significantly higher values than does the Cannon-Manning method. Furthermore, it was shown that, although shear thinning may result for certain asphalts when run in Cannon-Pressure instruments, there may also be compensating effects of pressure which can raise the viscosity. These variations are attributed to both differences in the flow mode (transient or steady state) and to effects of the imposed pressures.
To Sample the Moon
Authors: England AW
Published: March 2009

Within the framework of engineering constraints and of scientific uncertainties, the Apollo project has proved a great scientific success. A brief history is presented of the lunar exploration as it evolved through the unmanned probes to Apollo 16.
Role of Homogeneity in Powder Sampling
Authors: Grant CL , Pelton PA
Published: March 2009

When chemical analyses fail to satisfy the precision and accuracy requirements of a problem, it is common to attribute this difficulty to heterogeneity. In this paper, relationships between the properties of samples and standards and the methods used to analyze them are examined with respect to the influence of homogeneity.

The majority of chemical analyses are intended to characterize bulk composition. In this situation, a homogeneous material is one in which the unit that determines segregation is “very small” compared to the size of the analytical sample and in which the defining units are randomly distributed in the bulk. Both theoretical and experimental evidence is presented to demonstrate the magnitude of error contributed by various sizes of analytical samples and segregation units.

The error contributed by heterogeneity cannot be completely eliminated. Therefore, the analyst must attempt to devise a total analytical system with an acceptable sampling error.
Obtaining and Summarizing Subjective Impressions for Correlation with Analytical Measurements
Authors: Jenkins MW
Published: March 2009

Subjective thresholds of acuity, acceptability, or preference must be obtained to assure a manufacturer that his product is desirable. Subjective tests are often costly and time consuming. This delays decision making and product improvement or availability. Therefore, much effort has been extended in recent years to relate subjective impressions to analytical measurements such that a subjective study need not be run each time a product is tested.

The intent of this paper is to present a few studies, initiated to evaluate product appearance, wherein statistical techniques have been interrelated to obtain and describe the relationship between subjective impressions and objective measurements. The techniques used to obtain and summarize subjective impressions are presented in some detail. They are not necessarily new and are not all-inclusive but are applicable for testing a variety of products with modifications dictated by the product tested or the threshold level of subjects. The emphasis in experimental design is on the scaling of items by rank order or paired comparison techniques.
The Role of Some Alloying Elements on Radiation Hardening in Pressure Vessel Steels
Authors: Igata N , Watanabe K , Sato S
Published: March 2009

Recent trends in nuclear-pressure-vessel steels for light-water reactors have been toward Ni-Cr-Mo steels. The effect of minor elements—for example, copper and phosphorus—also has been investigated. In this study, the role of nickel, chromium, molybdenum, and copper was investigated to understand the irradiation behavior of pressure vessel steel, using internal friction measurement, transmission electron microscopy (TEM), and mechanical testing. The materials used were Fe-1Ni, Fe-0.25Cr, Fe-0.5Mo, and Fe-0.2Cu. They were annealed or quenched and irradiated 1 ∼ 3 × 1019 nvt(>1MeV) at 60 C (140 F), and postirradiation annealing was performed in the range 150∼450 C (302∼842 F).

The irradiation hardening was closely related to the amount of the solute nitrogen that corresponded to the amount of the complex defects in the aforementioned alloys. The irradiation hardening was primarily correlated with the strength of the interaction between solute nitrogen (or carbon) atoms. Other contributions of copper and molybdenum were considered.
On the Swelling Mechanism in the Irradiated Boron-Containing Stainless Steel
Authors: Altovskii IV , Elesin LA , Platonov PA , Savel'ev EG
Published: March 2009

The dilatometric investigation of the swelling of irradiated boron stainless steel has been carried out at a constant temperature and constant heating rate. A quantitative swelling model is proposed based on the mechanism of the capture of migrating equilibrium vacancies by immobile bubbles. The differential equation describing the process of establishing gas bubble equilibrium with time has been derived. The application of this equation made it possible to describe quantitatively all the stages of the material thermal annealing and determine the physical parameters characterizing the processes occurring in the material swelling.
Studies of Void Formation in Proton-Irradiated Type 316 and Titanium-Modified 316 Stainless Steels
Authors: Keefer DW , Pard AG , Kramer D
Published: March 2009

Void formation was studied in annealed Type 316 stainless steel irradiated with 1-MeV protons at 400 C, 500 C, and 600 C (752, 932, and 1112 F) for amounts of damage up to 50 displacements per atom (dpa). Prior to irradiation, the samples were injected with about 5 atomic ppm helium to simulate the fast-reactor situation, where helium is generated by (n,α) reactions. The volume increase at each temperature, as determined by quantitative electron microscopy, varied exponentially with displacement damage and the exponent increased with temperature. Volume increases exceeding 20 percent were associated with 50 dpa at 500 C and 20 dpa at 600 C; no limits on volume increases were apparent at any temperature. Void number density decreased and average void size increased with increasing temperature for a constant damage. A titanium-modified 316 stainless steel developed a very inhomogeneous void distribution when proton irradiated at 600 C. However, the addition of titanium did not appear to diminish the volume increase at damages between 5 and 10 dpa, when compared with ordinary Type 316 stainless steel.
Production of Voids in Stainless Steel by High-Voltage Electrons
Authors: Garner FA , Thomas LE
Published: March 2009

Neutron-induced void formation in 300 series stainless steels was simulated by 1000-keV electron bombardment of thin foils in a high-voltage microscope. Stereomicroscopy was used to determine the effect of surface proximity and to establish minimum foil thickness criteria for irradiations that would yield results characteristic of bulk material. Irradiation of specimens which are too thin yields misleading results, including an apparent saturation of swelling which actually is an artifact of the surface influence. Bulk-characteristic irradiations lead to volume increases as large as 100 percent without saturation.

Void nucleation in these irradiations was very sensitive to the initial microstructure. The thickness of zones denuded of voids at specimen surfaces was found to be very sensitive to temperature and surface conditions, particularly oxidation. The denuded zone width appears to be controlled by the effective vacancy migration behavior.
Effect of Neutron Irradiation on Fatigue Crack Propagation in Types 304 and 316 Stainless Steels at High Temperatures
Authors: Shahinian P , Watson HE , Smith HH
Published: March 2009

Resistance to fatigue crack propagation of pre- and postirradiation AISI Types 304 and 316 stainless steels was determined at 800 and 1100 F (427 and 593 C) using the fracture mechanics approach. The effect of irradiation on fatigue resistance was dependent upon test temperature and irradiation conditions. In general, irradiation degraded fatigue resistance at 1100 F (593 C) but at 800 F (427 C) enhancement as well was observed. In both steels irradiated in a thermal reactor to a fluence of 1.8 × 1021 n/cm2 >0.1 MeV, fatigue crack growth rates at 800 F (427 C) were lower than in the unirradiated steels for a given stress intensity factor range (ΔK). However, at 1100 F (593 C) the effect was reversed and crack growth rates were higher in the irradiated steels. Irradiation in a fast reactor to a fluence of ∼1.2 × 1022 n/cm2 >0.1 MeV caused fatigue crack growth rates at 800 F (427 C) to increase at low values of ΔK and decrease at high values of ΔK. At 1100 F (593 C) the crack growth rates in the irradiated steel were either the same as or higher than in the unirradiated steel. The influence of irradiation on fatigue life generally reflected the effect observed on crack growth rate.
Chapter 6—The Nature of Concrete
Authors: Powers TC
Published: March 2009

The term concrete can be construed to include a considerable variety of products made from portland cement or other cementing media, but in this publication the term concrete usually refers to a material which was at first a plastic mixture (or mixture that became plastic as a result of manipulation, especially vibration) of portland cement, water, air, and mineral aggregate. Therefore, this discussion of the nature of concrete will have the scope indicated by that description.
Chapter 13—Accelerated Strength Tests
Authors: Wills MH
Published: March 2009

Rapid construction practices throughout the concrete industry have brought increasing pressure on specifying agencies to assess the quality of concrete at an earlier age than 7 or 28 days after placement. Currently, the later age is still specified for compression tests of 152 by 304-mm (6 by 12-in.) cylinders of concrete as delivered to the job site in order to determine quality. During the 28-day period, it is not unusual for a multistory building to rise several floors before the strength tests are conducted. This situation is considered by many to be too precarious for construction to proceed on a sound technical basis and with adequate assurance of safety. Furthermore, extensive and costly delays are encountered when 28-day test results are low, since a field investigation may be necessary to verify the load-carrying capacity of the structure. Further delay is certain if concrete must be reinforced or replaced. Conversely, economics dictate that work continue without knowing quality, thus setting the stage for a catastrophic collision between advancing construction technology and the price owners are willing to pay for their capital facilities. Surely, an earlier assessment of concrete quality is absolutely essential.
Chapter 17—Thermal Properties
Authors: Rhodes JA
Published: March 2009

The thermal characteristics of concrete covered in this chapter are: thermal conductivity, specific heat, thermal expansion (or contraction), thermal diffusivity, and heat of hydration of cementitious materials. This last property is included because of its significant influence on the thermal and physical behavior of concrete in most of its uses.
Chapter 21—Bond with Reinforcing Steel
Authors: Lutz LA
Published: March 2009

Early experimenters and designers of reinforced concrete recognized that slip of the reinforcement had to be prevented in order to develop adequate bond and shear strengths and maintain the integrity of reinforced concrete members.
Chapter 22—Abrasion Resistance
Authors: Lane RO
Published: March 2009

This paper reviews the effects of important factors such as strength of concrete, mixture proportioning, selection of concrete-making materials, finishing procedures, and surface treatment on the wear resistance of concrete surfaces as determined by recent research. Newly revised or developed ASTM standards, Test for Abrasion Resistance of Concrete by Sandblasting (C 418) and Test for Abrasion Resistance of Horizontal Concrete Surfaces (C 779), provide test procedures for various types of wear simulating erosive or abrasive actions.
Chapter 28—Cement Content
Authors: Hime WG
Published: March 2009

Analyses for cement content are requested frequently by those who have encountered concrete that has shown low strength or other improper performance. Although such requests may often be poor substitutes for the far better “Determine why this concrete performed badly,” there are many occasions when a knowledge of the cement factor is desirable.
Chapter 29—Ready-Mixed Concrete
Authors: Gaynor RD
Published: March 2009

Ready-mixed concrete is concrete manufactured for delivery to a purchaser in a plastic and unhardened state [1,2]. The American Society for Testing and Materials (ASTM) has maintained ASTM Specification for Ready Mixed Concrete (C 94) since 1933 and ASTM Specification for Concrete Made by Volumetric Batching and Continuous Mixing (C 685) since 1971. This paper will review requirements of these two specifications and their relationship to other more general concrete specifications and codes. This discussion will be supplemented by background information on the industry, operating procedures, and special problems and circumstances. The references are intended to identify additional information in particular subject areas.
Chapter 42—Soundness and Deleterious Substances
Authors: Dolar-Mantuani L
Published: March 2009

During the past 100 or more years many tests have been developed and applied to assess the quality of concrete aggregates. This paper is a discussion of the significance of five aggregate quality tests currently in use. One of them, the sulfate soundness test (ASTM Test for Soundness of Aggregates by Use of Sodium Sulfate or Magnesium Sulfate (C 88)), is perhaps the most widely used of all methods for determining the overall quality of aggregate. The other four tests are used to determine the presence of specific harmful particles or substances which influence the mix proportions of fresh concrete or its early stage hardening, or which damage the concrete surface under specific circumstances.
Chapter 48—Cellular Concrete
Authors: Legatski LM
Published: March 2009

The basic contribution of cellular concrete to the field of concrete technology is the ability to control the density of concrete over a wide range. Density control is achieved by adding a calculated amount of a proper foam to a slurry of water and cement, with or without the addition of sand or other aggregate. The wet density range for cellular concrete mixes is usually considered to be from about 320 to 1920 kg/m3 (20 to 120 lb/ft3).
Fracture Mechanics for Fibrous Composites
Authors: Sih GC , Hilton PD , Badaliance R , Shenberger PS , Villarreal G
Published: March 2009

In the present paper, a combined theoretical and experimental research effort for investigating the application of fracture mechanics to composite systems is carried out. Preliminary results are presented which include the development of two fiber reinforced composite crack models, one with a low-fiber-volume fraction and the other a high-fiber-volume fraction, and corresponding experimental data.

The qualitative features of the theoretical prediction are in agreement with the experimental data indicating that there exists an optimum fiber volume fraction for which the composite achieves maximum fracture toughness. Tests were performed on unidirectional fiber reinforced composites with the crack running parallel to the fibers. For this arrangement, the current theory of fracture mechanics is shown to apply with good accuracy for glass fiber composites. This is accomplished by performing two independent fracture tests, the results of which are checked by an analysis of the crack system. A more elaborate analytical model is required for studying the graphite fiber composite.
Influence of Nitrogen on the Creep-Rupture Properties of Type 316 Steel
Authors: Cullen TM , Davis MW
Published: March 2009

An experimental program has been conducted to determine the influence of nitrogen on the creep and rupture properties of Type 316 stainless steel. A series of commercial and laboratory heats with similar base composition but varying nitrogen contents were utilized in the study. The nitrogen content of the heats ranged from 0.039 to 0.15 percent.

The creep and rupture strengths of the steel at 1200 F increased with increasing nitrogen level. The stress for rupture in 1000 and 10 000 h was approximately 40 percent higher for the 0.15 percent nitrogen heat than for the 0.039 percent nitrogen alloy. The stress to produce a minimum creep rate of 0.01 percent per 1000 h increased by 50 percent over the same nitrogen range.

A ferrite containing heat was also tested in the program. Ferrite was shown to decrease creep resistance and increase rupture ductility. No significant influence of this phase was noted with respect to rupture strength.

Various parameter extrapolation methods were compared in their ability to predict the location of a break in the rupture curve of one of the nitrogen containing heats. Long time rupture tests were conducted to pinpoint the exact position of this change in slope.
Effect of Elevated Temperatures on the Properties of Nitrogen-Bearing Type 216 Steel
Authors: Chivinsky JA
Published: March 2009

Preliminary data indicate that Type 216, a high-nitrogen and molybdenum-bearing austenitic stainless steel offers improved strength over conventional Type 316 to temperatures approaching 1350 F (732 C). However, impact and intergranular corrosion tests conducted on the material suggest that Type 216 may be restricted to service temperatures near 1200 F (649 C). The superior strength of Type 216, coupled with its excellent corrosion properties, makes it attractive for application in the process industries (chemical, petrochemical, pulp, paper, etc.) as well as marine and space markets.
Specifications for Cryogenic Propellants and Pressurizing Gases
Authors: Forbes FS
Published: March 2009

Cryogenic propellants and pressurizing gases have been and will continue to be used for missile and space propulsion systems. To maintain the high degree of reliability that these propulsion systems have exhibited, close control of propellant quality is necessary. Specifications are the basic documents that establish the technical requirements for procurement purposes. These requirements are dictated by the needs of the user, with due consideration given to the manufacturing ability of the suppliers, and possible deterioration of the product during handling and storage. Specifications also contain quality assurrance provisions that detail the sampling plans and analytical procedures to be used to ensure that the propellant conforms to the specified requirements. Gas chromatography has been widely accepted as the principal method of analysis for cryogenic and gaseous materials.

Specifications are continually revised and updated as required by the rocket community. The rationale for the establishment of the specific requirements for oxygen, nitrogen, helium, fluorine, and hydrogen is presented. Current sampling techniques and analytical methods for these products are also reviewed. Other cryogens, such as OF2 and methane, have received limited attention and are briefly discussed.
Recording Fluxmeter of High Accuracy and Sensitivity with Galvanometer-Photoelectric Integrators
Authors: Cioffi PP
Published: March 2009

A hysteresigraph of high accuracy and sensitivity is described. Using galvanometer-photoelectric integrators, this instrument was the first precision recording fluxmeter for tracing accurately and rapidly magnetization curves and hysteresis loops directly on standard rectangular coordinate paper to any desired scale for direct reading of the data. Overall error of this hysteresigraph can be reduced to 0.2 percent by calibration of the overall system with a precision search coil of certified accuracy and a magnetic field accurately determined by means of a nuclear resonance magnetometer.
An Integrating Type of Electronic Hysteresigraph
Authors: DeMott EG
Published: March 2009

An electronic hysteresigraph, which integrates without recourse to electromechanical means and is free of drift, has been developed. In operation, a search coil surrounds the magnetic specimen to be tested, and the specimen is then subjected to a change in externally applied magnetic field strength. The time integral of the potential induced in the search coil is a measure of the magnetic flux change in the specimen. The induced potential is applied to a solid-state voltage-to-frequency converter which produces a series of output pulses, the number of which is proportional to ∫e dt. These pulses are summed on a digital counter to give a measure of the flux change. A digital-to-analog converter then provides a d-c output which drives the Y-axis of an X-Y recorder.

A signal proportional to the applied magnetic field strength is simultaneously fed to the X-axis of the recorder, and a continuous B versus H plot is obtained. This is a real-time mode as the response of the various measuring elements is practically instantaneous.

In considering the integrator, it is interesting to note that absolute accuracy traceability in calibrating the voltage-to-frequency converter is referred directly to the volt, as represented by the standard cell, and to the second, as represented by a crystal-controlled time base. This is in contrast to the generally used secondary standards of mutual inductance and current shunt millivolt drop.
Corrosion Standards and Control in the Gas Industry
Authors: Bull LM
Published: March 2009

The natural gas industry is concerned with the production, transmission, distribution, storage, processing, and utilization of natural gas. High efficiency and safety requirements result in the need for effective corrosion control of these facilities. These facilities are subject to marine, underground, and various atmospheric and process environments. A complete description of materials and environments involved in the functions of the gas industry are too numerous to completely describe herein.
Corrosion Standards and Control in the Pipeline Industry
Authors: Peabody AW
Published: March 2009

The discussion in this chapter concerns itself with any pipeline used for the transportation of materials. Materials involved can include, but are not necessarily limited to, fuel gas, petroleum and petroleum products, water, chemical solutions, effluents from manufacturing plants, and solids being transported in slurry form. Our consideration of corrosion will concern itself with external pipeline corrosion which may occur underground, in a submerged condition, or exposed to the atmosphere. Internal corrosion will be considered for those pipelines carrying material which can be expected to cause internal corrosion under specific conditions. Discussion of corrosion will concern itself with metallic pipelines as opposed to nonmetal pipelines (used in some instances) which are subject to deterioration with time rather than corrosion with time, which is taken as a function of metals only.
Corrosion Standards and Control in the Iron and Steel Industry
Authors: Leckie HP
Published: March 2009

Corrosion testing in the steel producing industry is utilized to (a) provide a basis for internal quality control standards, (b) establish quality and performance parameters with respect to the final product utilization and (c) serve as a comparison standard in the development of new ferrous base products having improved corrosion resistance. The major markets served by the steel industry are automotive, construction, containers, rails, electrical, appliance and agriculture and both accelerated and field tests on steel products reflect the specific requirements in corrosion resistance properties for these industries. Any discussion of corrosion testing of steels must necessarily include coatings (both metallic and nonmetallic) since the shipped tonnages of coated steel products are large and continue to increase on a percentage basis year by year. Furthermore, although stainless and heat resisting steels represent less than one percent [1] of steel shipments in the United States, the more critical applications to which these materials are subjected, together with the specific forms of corrosion related failures experienced, warrant their inclusion in any description of the use of corrosion standards in the steel industry.
Use of Old Telephone Plastic-A Feasibility Study
Authors: Squitieri LA
Published: March 2009

Environmental control through recycling has become a popular issue both for the country and Western Electric. Western Electric repairs over 20 million telephone sets each year, and, in the process, they generate a substantial volume of rubbish of which 12 percent is scrap telephone plastic and 85 percent is cardboard and wood. Most of the scrap telephone plastic is ABS, a high impact material. The same type of plastic is used in football helmets and automobile parts.

A study to determine the feasibility of recycling this scrap plastic was made. In order to facilitate the study, a materials handling shop tray presently made of virgin acrylonitrile butadiene and styrene (ABS) plastic was used to produce samples. Some of the sample trays were successful field tests. The mechanical properties of recycled plastic were also determined.

As would be expected, the mechanical properties of recycled materials were reduced when compared to new plastic. However, it did not present a problem with the sample trays field tested. The data obtained indicated that the results were well within the range of published data for new ABS.

Plastic recycling is not new. Recycling of highly contaminated plastic is unique and practical and, when properly prepared, can actually reduce manufacturing costs.
Fatigue at High Temperature
Authors: Coffin LF
Published: March 2009

This report was prepared as the keynote address given at the 1972 Symposium on Fatigue at Elevated Temperatures at the University of Connecticut, 18–23 June, 1972. It describes the high-temperature fatigue problem as a failure process in a notch in some structure involving nucleation and early growth at the notch root, high-strain crack propagation through the plastic zone of the notch, and elastic crack growth to ultimate failure. Several of the important disciplines bearing on these three steps in the failure process are discussed. Particular attention is given to a description of the high-temperature phenomenology, distinctions between high- and low-cycle fatigue effects at high temperature, failure criteria including frequency and holdtime effects, the importance of the environment vis-a-vis creep in considering time effects on fatigue behavior, high-strain crack propagation, elastic crack growth, ratchetting effects, and methods for treating notches.
Ultrasonic Fatigue in Steam with Small Amounts of Sodium Chloride
Authors: Conn AF , Nielsen NA
Published: March 2009

Premature failure of steam turbines is a problem in both manufacturing operations and power generation plants. Information on the influence of contaminant sodium chloride in steam on the corrosion fatigue life of Type 403 stainless steel, the most common steam-turbine blade material, is needed. High-frequency fatigue tests were conducted on bare specimens of Type 403 steel, both in a pure-steam environment at 250 F, and in steam contaminated with small quantities of sodium chloride. Tests were also conducted on shot-peened specimens diffusion-coated for corrosion protection. With 2000 ppm of salt in the steam, considerable reduction in fatigue life was observed for bare steel in relatively brief tests at high ultrasonic frequencies. Considerable increase in fatigue life was observed for the shot-peened and coated specimens. The results show that even trace quantities of a corrodent at elevated temperatures can greatly reduce fatigue lifetimes of steam-turbine blade material. The effectiveness of the coating system was demonstrated clearly in these tests, suggesting important increases in the operational lifetimes of steam-turbine equipment.
Effect of Carbon Content on High-Temperature Properties of 2%Cr-1Mo Steels
Authors: Seeley RR , Zeisloft RH
Published: March 2009

The 2¼Cr-1Mo steel is an attractive material for liquid metal handling systems such as a liquid sodium loop of a liquid metal fast breeder reactor (LMFBR) steam generator. However, mass transfer of carbon from the chromium-molybdenum steel can occur in such applications and hence can alter the mechanical properties of the material. The object of this work was to determine the effect of low-carbon contents on the tensile, stress rupture, and low-cycle fatigue properties of 2 ¼Cr-1Mo steels at elevated temperatures.

Commercial and laboratory heats of material with carbon contents of about 0.02 to 0.19 percent were tested in the annealed condition. These carbon contents were obtained by casting to the desired level and by decarburization. The results of our tests indicate that lower carbon contents decrease strength levels, stress rupture properties, and low-cycle fatigue resistance at elevated temperatures. The decarburized material may suffer greater strength losses than the cast-to-low carbon material.
Bend Fatigue of Two Iron-Nickel-Base Superalloys at Elevated Temperature
Authors: Opinsky AJ
Published: March 2009

The iron-nickel-base superalloy A-286 and its improved version, intermediate-aged V-57, were examined in bend fatigue at 950 to 1100 F (510 to 593 C) to determine whether using V-57 would be advantageous in low-frequency applications. The superiority might be expected because the latter is better in stress rupture than A-286. Nonreversed bending was done at frequencies close to 0.1 and 1 cpm, with a few tests at 10 cpm. The transition fatigue life, where the elastic and plastic strain ranges are equal, is below 500 cycles. Since most purely cyclic applications will involve much longer lives, the fatigue component of damage in these applications will be in the high-cycle fatigue regime. The data, which show V-57 to be superior to A-286 at 950 to 1100 F (510 to 593 C), also indicate that test frequencies should be chosen carefully to obtain meaningful data. There are several indications that the specimens can undergo further aging during testing and that their fatigue behavior is affected by the aging.
Thermal Fatigue Behavior of T-111 and ASTAR 811C in Ultrahigh Vacuum
Authors: Sheffler KD , Doble GS
Published: March 2009

The thermal fatigue behavior of the tantalum alloys T-111 (Ta-8W-2Hf) and ASTAR 811C (Ta-8W-1Re-0.7Hf-0.025C) has been evaluated using completely reversed push-pull fatigue tests conducted in ultrahigh vacuum with independently programmed temperature and strain cycles. Test results showed that cycling of the test temperature simultaneously with the mechanical strain in most cases significantly reduced the cycles to failure of both alloys compared to isothermal testing. Notched specimens had reduced lives under isothermal conditions, but the presence of a notch or use of a 1-h holdtime provided only a small further decrease in life for the temperature cycled tests. Compressive stress at the maximum temperature produced longer lives than tensile stress. ASTAR 811C was more fatigue resistant than T-111 isothermally and did not have as great a decrease in life with thermal cycling. Results are analyzed by partition of plastic strains into creep and creep-independent components and considering where each component was active in the hysteresis cycle.
Test Results of Fatigue at Elevated Temperatures on Aeronautical Materials
Authors: Vidal GP , Galmard PL
Published: March 2009

This paper shows how fatigue tests at elevated temperature solve many problems pertaining to aeronautical materials. Prolonged periods (5000 or 10 000 h) at 150 C (302 F) did not diminish the fatigue limit at 150 C (302 F) of the aluminum alloy 2618-T6. Consequently, the aerodynamic heating of airframes at Mach 2 does not reduce the fatigue limit of this alloy.

The “bright shot” or shot-peened surface conditions do not increase the hot-fatigue limit of a heat-resistant alloy. The Office National Etudes et Recherches Aérospatiales (ONERA) process for the chromaluminization of the heat-resistant alloy Inconel 713 does not modify the fatigue limit at 700 C (1290 F). Similarly, gases resulting from kerosine (0.5 percent sulfur) combustion do not reduce the hot-fatigue resistance of four heat resistant alloys. The fatigue characteristics of various superalloys— unidirectional or composites made by the ONERA process—at 800 C (1470 F)—are equal to or even superior to those classic heat-resistant alloys, cast or forged. A cermet of 50 percent of chromium and 50 percent of alumina retains, even at 1200 C (2190 F), a resistance to fluctuating flexure stresses of 69 ± 49 MN/m2 (10 ± 7 ksi).