bluuebunny/crossref_metadata_2025 huggingface dataset:
Notarized And Baptismal Manumissions in the Parish Of SÃO José Do Rio Das Mortes, Minas Gerais (C. 1750-1850)
Authors: Libby Douglas Cole , Graça Filho Afonso De Alencastro
Published: September 2009

As regards the slave societies of the Americas, it is hard to imagine a more palpable example of social mobility than manumissions. The fact that exslaves were able to carve out a space for themselves within the larger slave societies attests to their resilience—a resilience that must have played a role in obtaining freedom in the first place—and demonstrates that a considerable measure of social and racial flux existed in at least some of those societies. Manumission and miscegenation, independendy or in association with one another, decisively contributed to the sometimes explosive growth of colored and mestizo populations, which came to characterize large parts of Latin America. Few better examples exist than Brazil, where it was not at all uncommon for ex-slaves to become slaveholders in their own right.
Broken Spears or Broken Bones: Evolution of the Most Famous Line in Nahuatl
Authors: Schwaller John F. , Leon-Pórtilla Miguel
Published: September 2009

Arguably the line “Broken Spears” is the most famous in Nahuatl. Any undergraduate student who has taken a course in Latin American history, literature, or anthropology has in all likelihood come across the line. It, of course, comes from the title of Miguel Leon-Portilla's book of the same name. The line appears in a description of Tlatelolco following the destruction of the city by the Spanish in the conquest of Mexico:
Broken spears lie in the roadsWe have torn our hair in our griefThe houses are roofless now, and their wallsAre red with blood.

This evocative image has dominated much of the imagination of two generations of college students.
Re-reading George Eliot's "Natural History": Marian Evans, "the People," and the Periodical
Authors: Dillane Fionnuala
Published: September 2009

George Eliot’s ‘The Natural History of German Life’, which appeared in the Westminster Review in July 1856 has become a central reference point in George Eliot studies and in accounts of nineteenth-century literary realism because of its supposed compact articulation of the future novelist’s “doctrine of sympathy” offered by the still anonymous Marian Evans. This essay argues that Natural History offers a more equivocal and ultimately intriguing display of Marian Evans’s discomfort with reviewing and with the Westminster Review . In this fractured and much misrepresented essay, Evans emerges as an ironic, evasive voice, ultimately subverting the role of the generalizing authoritative critic, in contrast to George Henry Lewes, who in an article on in the same issue of the Review , embodies fully the generalizing corporate voice of the mid-century reviewer.
The Transatlantic Moonstone : A Study of the Illustrated Serial in Harper's Weekly
Authors: Leighton Mary Elizabeth , Surridge Lisa
Published: September 2009

This article examines Wilkie Collins’s The Moonstone (1868), a novel that has attracted varied ideological critique yet whose different transatlantic forms remain understudied. In an international market ungoverned by copyright law, Collins sold his story on both sides of the Atlantic, but the serial of The Moonstone that reached American readers differed markedly from the British text. Whereas the British All the Year Round serial was unillustrated, Harper’s Weekly advertised the American serial as “richly illustrated.” Harper’s illustrations formed an intrinsic part of the American Moonstone , heightening the text’s sensationalism, complicating its intricate narrative structure, and shifting its treatment of gender, disability, class, and race.
John Leech and the Shaping of the Victorian Cartoon: The Context of Respectability
Authors: Miller Henry J.
Published: September 2009

The Punch artist John Leech was an influential and popular figure in Victorian culture. This article uses Leech to explore the wider context in which cartoons and illustrators operated and presents a nuanced view of the pressures favouring respectability. A distinctive cultural climate was formed by a set of ideas about what cartoons should be. The development of wood engraving and the periodical press created a publishing environment which benefited artists who worked for successful periodicals like Punch , by enhancing their financial, social, and artistic position, whilst slightly diminishing their autonomy.
Balance of power – dynamic regulation of chromatin in plant development
Authors: Lafos Marcel , Schubert Daniel
Published: September 2009

Chromatin states profoundly determine and maintain gene activity and gene repression in eukaryotic organisms. Regulation of chromatin involves chromatin remodeling, chromatin modifications and exchange of chromatin components and is linked to DNA methylation in some cases. In plants and other organisms, chromatin proteins control many developmental pathways, integrate changes in the environment and can confer a cellular memory of these cues. Here, we review the molecular mechanisms that provide a dynamic regulation of chromatin in a cell. In addition, we discuss how chromatin needs to be flexibly regulated during plant growth to confer stable expression states that can occasionally be reset, e.g., owing to changes in the environment and progression of development.
Chemotaxis: how bacteria use memory
Authors: Vladimirov Nikita , Sourjik Victor
Published: September 2009

Bacterial chemotaxis represents one of the simplest and best studied examples of unicellular behavior. Chemotaxis allows swimming bacterial cells to follow chemical gradients in the environment by performing temporal comparisons of ligand concentrations. The process of chemotaxis in the model bacterium Escherichia coli has been studied in great molecular detail over the past 40 years, using a large range of experimental tools to investigate physiology, genetics and biochemistry of the system. The abundance of quantitative experimental data enabled detailed computational modeling of the pathway and theoretical analyses of such properties as robustness and signal amplification. Because of the temporal mode of gradient sensing in bacterial chemotaxis, molecular memory is an essential component of the chemotaxis pathway. Recent studies suggest that the memory time scale has been evolutionary optimized to perform optimal comparisons of stimuli while swimming in the gradient. Moreover, noise in the adaptation system, which results from variations of the adaptation rate both over time and among cells, might be beneficial for the overall chemotactic performance of the population.
The epigenetic bottleneck of neurodegenerative and psychiatric diseases
Authors: Sananbenesi Farahnaz , Fischer Andre
Published: September 2009

The orchestrated expression of genes is essential for the development and survival of every organism. In addition to the role of transcription factors, the availability of genes for transcription is controlled by a series of proteins that regulate epigenetic chromatin remodeling. The two most studied epigenetic phenomena are DNA methylation and histone-tail modifications. Although a large body of literature implicates the deregulation of histone acetylation and DNA methylation with the pathogenesis of cancer, recently epigenetic mechanisms have also gained much attention in the neuroscientific community. In fact, a new field of research is rapidly emerging and there is now accumulating evidence that the molecular machinery that regulates histone acetylation and DNA methylation is intimately involved in synaptic plasticity and is essential for learning and memory. Importantly, dysfunction of epigenetic gene expression in the brain might be involved in neurodegenerative and psychiatric diseases. In particular, it was found that inhibition of histone deacetylases attenuates synaptic and neuronal loss in animal models for various neurodegenerative diseases and improves cognitive function. In this article, we will summarize recent data in the novel field of neuroepigenetics and discuss the question why epigenetic strategies are suitable therapeutic approaches for the treatment of brain diseases.
Mechanistic insights in light-induced cAMP production by photoactivated adenylyl cyclase alpha (PACα)
Authors: Looser Jens , Schröder-Lang Saskia , Hegemann Peter , Nagel Georg
Published: September 2009

The flagellate Euglena gracilis contains as photoreceptor complex a heterotetrameric light-sensitive adenylyl cyclase (AC), consisting of the flavoproteins PACα and PACβ. Previously, we demonstrated the functional expression of PACα and PACβ in oocytes from Xenopus laevis and of PACα in different animal cell types. Both yielded a blue light-induced increase of cellular [cAMP]. Here, we report that the action spectrum of PACα is flavoprotein-typical, with maxima at ∼380 and ∼470 nm. Mutational analysis of PACα yields a model for its structure and function. PACα shows a basal AC activity in the dark which is unaffected by mutating the conserved tyrosines in the two flavin-binding domains (F1, F2), Y60 in F1 and Y472 in F2. Y60 in F1 is, however, essential for photoactivation as light-stimulation of cyclase activity is completely lost in the F1 mutant Y60F. This effect does not occur in the respective mutation in F2 (Y472F). Mutating the two cyclase domains (C1, C2) indicated that C1 and C2 form a heterodimeric catalytic center as in mammalian class III cyclases. Interaction of C1 with C2 in the same molecule could be excluded as coexpression of non-functional C1 and C2 mutants restored light-induced cyclase activity. Our results strongly suggest an intermolecular dimerization of C1 and C2 domains on PACα for a functional enzyme.
Protein carboxyl methylation and the biochemistry of memory
Authors: Li Zhu , Stock Jeffry B.
Published: September 2009

Bacterial chemotaxis is mediated by two reversible protein modification chemistries: phosphorylation and carboxyl methylation. Attractants bind to membrane chemoreceptors that control the activity of a protein kinase which acts in turn to control flagellar motor activity. Coordinate changes in receptor carboxyl methylation provide a negative feedback mechanism that serves a memory function. Protein carboxyl methylation might play an analogous role in the nervous system. Two protein carboxyl methyltransferases serve to regulate signal transduction pathways in eukaryotic cells. One is highly expressed in the Purkinje layer of the cerebellum where it methyl esterifies prenylated cysteine residues at the carboxyl-termini of Ras-related and heterotrimeric G-proteins. The other is abundant throughout the brain where it methylates the carboxyl-terminus of protein phosphatase 2A. The phosphatase methyltransferase and the protein methylesterase that reverses phosphatase methylation are structurally related to the corresponding bacterial chemotaxis methylating and demethylating enzymes. Recent results indicate that deficiencies in phosphatase methylation play an important role in the etiology of Alzheimer's disease.
Memory and neural networks on the basis of color centers in solids
Authors: Winnacker Albrecht , Osvet Andres
Published: September 2009

Optical data recording is one of the most widely used and efficient systems of memory in the non-living world. The application of color centers in this context offers not only systems of high speed in writing and read-out due to a high degree of parallelism in data handling but also a possibility to set up models of neural networks. In this way, systems with a high potential for image processing, pattern recognition and logical operations can be constructed. A limitation to storage density is given by the diffraction limit of optical data recording. It is shown that this limitation can at least in principle be overcome by the principle of spectral hole burning, which results in systems of storage capacities close to the human brain system.
The mechanism of ATP-dependent RNA unwinding by DEAD box proteins
Authors: Hilbert Manuel , Karow Anne R. , Klostermeier Dagmar
Published: September 2009

DEAD box proteins catalyze the ATP-dependent unwinding of double-stranded RNA (dsRNA). In addition, they facilitate protein displacement and remodeling of RNA or RNA/protein complexes. Their hallmark feature is local destabilization of RNA duplexes. Here, we summarize current data on the DEAD box protein mechanism and present a model for RNA unwinding that integrates recent data on the effect of ATP analogs and mutations on DEAD box protein activity. DEAD box proteins share a conserved helicase core with two flexibly linked RecA-like domains that contain all helicase signature motifs. Variable flanking regions contribute to substrate binding and modulate activity. In the presence of ATP and RNA, the helicase core adopts a compact, closed conformation with extensive interdomain contacts and high affinity for RNA. In the closed conformation, the RecA-like domains form a catalytic site for ATP hydrolysis and a continuous RNA binding site. A kink in the backbone of the bound RNA locally destabilizes the duplex. Rearrangement of this initial complex generates a hydrolysis- and unwinding-competent state. From this complex, the first RNA strand can dissociate. After ATP hydrolysis and phosphate release, the DEAD box protein returns to a low-affinity state for RNA. Dissociation of the second RNA strand and reopening of the cleft in the helicase core allow for further catalytic cycles.
Elafin is specifically inactivated by RgpB from Porphyromonas gingivalis by distinct proteolytic cleavage
Authors: Kantyka Tomasz , Latendorf Ties , Wiedow Oliver , Bartels Joachim , Gläser Regine , Dubin Grzegorz , Schröder Jens-Michael , Potempa Jan , Meyer-Hoffert Ulf
Published: September 2009

Porphyromonas gingivalis, the major causative bacterium of periodontitis, contributes significantly to elevated proteolytic activity at periodontal pockets owing to the presence of both bacteria and host, predominantly neutrophil-derived, serine proteases. Normally the activity of the latter enzymes is tightly regulated by endogenous proteins, including elafin, a potent neutrophil elastase and proteinase 3 inhibitor released from epithelial cells at sites of inflammation. Here, we report that all three gingipains (HRgpA, RgpB, and Kgp) have the ability to degrade elafin, with RgpB being far more efficient than other gingipains. RgpB efficiently inactivates the inhibitory activity of elafin at subnanomolar concentrations through proteolysis limited to the Arg22-Cys23 peptide bond within the surface loop harboring the inhibitor active site. Notably, elafin resists inactivation by several Staphylococcus aureus-derived serine and cysteine proteases, confirming the high stability of this protein against proteolytic degradation. Therefore, we conclude that elafin inactivation by RgpB represents a specific pathogenic adaptation of P. gingivalis to disturb the protease-protease inhibitor balance in the infected gingival tissue. This contributes to enhanced degradation of host proteins and generation of a pool of peptides serving as nutrients for this asaccharolytic pathogen.
Stimulation of fibroblast proliferation by the plant cysteine protease CMS2MS2 is independent of its proteolytic activity and requires ERK activation
Authors: Gomes Marco Túlio R. , Turchetti Andréia P. , Lopes Miriam T.P. , Salas Carlos E.
Published: September 2009

The cysteine protease CMS2MS2 fromCarica candamarcensislatex has been shown to enhance proliferation of L929 fibroblast and to activate the extracellular signal-regulated protein kinase (ERK). In experiments with CMS2MS2 irreversibly inhibited by E-64, the proliferative effect on fibroblasts remains unaffected. ERK phosphorylation mediated by CMS2MS2 was abolished in the presence of PD 98059 or U0126, both MAPK cascade inhibitors. In addition, these inhibitors suppress the mitogenic activity of intact CMS2MS2 or CMS2MS2-E-64. Furthermore, ERK phosphorylation and the mitogenic effect are partially suppressed by a phospholipase C (PLC) inhibitor. These data suggest that the mitogenic effect of CMS2MS2 on fibroblasts is independent of its proteolytic activity, requires ERK phosphorylation, and involves activation of PLC.
Fracture Toughness Studies on Ceramics and Ceramic Particulate Composites at Different Temperatures
Authors: Gogotsi G
Published: September 2009

The fracture toughness of alumina, zirconia, silicon nitride, and silicon carbide ceramics as well as silicon nitride and silicon carbide particulate composites were studied by the single edge V-notched beam (SEVNB) method over a wide temperature range. Manual and mechanical procedures for V-notch polishing-out and three- and four- point flexure tests were developed. Load—deflection diagrams for V-notched specimens contributed to better understanding of the deformation behavior of ceramics at room temperature and 1300–1400 °C. SENB (single edge notched beam) and SEPB (single edge precracked beam) as well as micro-Raman spectroscopy data were used to analyze the SEVPB results. The ratio between SEVNB and SENB results is about 0.6 for elastic materials and over 0.9 for inelastic ones. The results for zirconia, in the case of a V-notch root radius less than 5-7 μm, are in good agreement with SEPB results. The polishing-out of a V-notch does not lead to the tetragonalmonoclinic phase transformation in these materials.
Evaluation of Standard Charpy Impact Properties with Subsized Specimens
Authors: Yamamoto T , Yabuki K , Matsui H , Odette GR , Lucas GE
Published: September 2009

Evaluation methodology of standard Charpy impact properties in the cleavage fracture region from subsized specimen test results has been demonstrated. It consists of 1) subsized Charpy V-notch impact tests; 2) tensile tests at various temperatures and strain rates; and 3) three dimensional finite element method (FEM) simulations of the impact test with a temperature and strain rate dependent constitutive equation and a cleavage fracture model that is based on a stress-critical area criteria. The standard impact properties of a ferritic/martensitic steel (JFMS) in the cleavage facture region have been evaluated, and there was reasonable agreement between simulations and experimental results.
In-Beam Fatigue Response of a Low Activation Ferritic Steel at 60°C
Authors: Murase Y , Nagakawa J , Yamamoto N
Published: September 2009

Fatigue response was investigated for a low activation ferritic steel, F82H, under in-beam (dynamic), post-irradiation (static) and unirradiation conditions with 17 MeV protons at 60°C. Miniaturized specimens with a side notch in gauge were tested in a stress-control mode with triangular wave at two different loading ratios; R (σmax/σmin) = 0.44 (375 MPa ↔ 165 MPa) and R = 0.2 (375 MPa ↔ 75 MPa). Fracture surfaces were examined by a scanning electron microscope (SEM) for all specimens. Some evidence of the dynamic irradiation effect on fatigue response was observed in both fatigue tests and the SEM evaluations. The dynamic effect was more influential than the static effect at R = 0.44, while it was suppressed at R = 0.2 where the larger loading amplitude was imposed on the specimen. Balance between defect flux and fatigue damage development would control the dynamic irradiation effect.
Small Punch Test : EPRI-CEA Finite Element Simulation Benchmark and Inverse Method for the Estimation of Elastic Plastic Behavior
Authors: Catherine CS , Messier J , Poussard C , Rosinski S , Foulds J
Published: September 2009

Prolonging the service life of nuclear power plants and more stringent safety requirements are increasing the need for miniature mechanical tests such as the Small Punch Test (SPT). This test was initially developed in the early 1980s at MIT and further developments with more extensive use were achieved by EPRI with a continuous program between 1990 and 1999.

The present investigation is first based on a finite element simulation benchmark between EPRI and CEA. This provided a reciprocal validation of the numerical simulation of this test for an A533 B steel at room temperature. The loading mode progressively evolves from bending towards biaxial membrane loading of the specimen. Strain energy density was also computed as the failure criterion and the maximum value observed at experimental crack initiation is about 116 MJ/m3.

A parametric finite element study was undertaken in order to evaluate the influence of factors such as specimen thickness, friction, yield strength, strain hardening coefficient, etc. Starting from this parametric study, an automatic routine was built which estimates the elastic-plastic Ramberg-Osgood stress strain relation. The need for standardization of this test will be underlined.
Study of Evaluating Method for Non-Metallic Inclusions and Development of Slag Refining for Bearing Steel
Authors: Nishikawa T , Nagayama H , Nishimon S , Asai K , Fujii I , Sugimoto T
Published: September 2009

The evaluation of the nonmetallic inclusions is very important to estimate the rolling contact fatigue life of bearing steel. The study of the ultrasonic testing as nondestructive testing made it clear that the nonmetallic inclusion over 10 μm could be detected and there was a relationship between the flaking and the nonmstallic inclusions in the rolling contact fatigue life testing. On the extraction of the acid solution and Coulter counter method, the changes of the nonmetallic inclusions in molten steel was analyzed and the higher basicity less SiO2 slag refining reduced the quantity of the nonmetallic inclusions over 20 μm size to 75% compared with the conventional refining method.
Structural Performance of Laminated Glass Made with a “Stiff” Interlayer
Authors: Bennison SJ , Smith CA , Duser AV , Jagota A
Published: September 2009

The growing demand for laminated glass in building facades and interiors is driving the development of new interlayers that extend the performance of laminated glass. In this contribution we discuss the structural performance of laminates made with such a new interlayer: SentryGlas® Plus. This new interlayer is significantly stiffer and tougher than traditional PVBs and provides enhanced structural performance in many applications. The mechanical properties of a stiff interlayer lead to benefits in three main areas: 1) glass strength; 2) stiffness and creep resistance, both before and after glass breakage; 3) temperature performance. Strength benefits are realized in applications where significant bending stresses develop during loading, such as: laminates with two sided support, balustrades (cantilevers), bolted glass and laminates supported on three sides. Enhanced post glass breakage performance expands the design envelope for glass in horizontal and sloped applications such as overhead glazing, glass floors and stairs. All of these structural properties are maintained to higher temperatures as compared to conventional PVB.
Fracture Resistance Testing of Monolithic and Composite Brittle Materials
Authors: Salem JA , Quinn GD , Jenkins MG
Published: September 2009

Description

STP 1409 features 14 peer-reviewed papers that summarize the latest methods for the measurement of fracture toughness, slow crack growth, and biaxial strength. It also identifies new areas for fracture toughness test methods development and standardization, such as testing of complex materials, elevated temperature measurement, and R-curve measurement.

5 sections cover:

Plenary Session--discusses 30 years of progress in fracture mechanics of brittle materials.

Implications For Design and Testing--focuses on the analysis of plates for biaxial strength testing and the transition in measured fracture toughness from a value associated with the properties of a single grain to the polycrystalline value.

Fracture Toughness Standardization--examines 3 techniques that were developed and standardized as part of ASTM C 1421 Standard Test Methods for Determination of Fracture Toughness of Advanced Ceramics at Ambient Temperatures. These techniques show convergence when good metrology is employed. In addition to standardized techniques, this section discusses the single edged V-notched beam method that is on a fast track for standardization in Europe.

Crack Growth Resistance--covers testing of functionally graded materials, elevated temperature R-curve testing, and the study of a toughening mechanism. Although most researchers applied classical mechanical techniques for the measurement of fracture toughness or crack growth resistance, both theoretical and fractographic methods were also presented.

Unique Materials and Environmental Effects--examines elevated temperature fracture toughness testing of particulate reinforced ceramic composites, thermal and environmental effects on the fracture toughness of titanium carbonitrides for machining, and environmental interactions that lead to rate effects in "dynamic fatigue" (i.e., stress corrosion) testing.

Audience: Mechanical Engineers • Ceramic Engineers • Materials Scientists • Designers
Small Specimen Test Techniques: Fourth Volume
Authors: Sokolov MA , Landes JD , Lucas GE
Published: September 2009

Description

STP 1418 features a global review of the latest research in small volume specimen testing. 31 peer-reviewed papers from an international collection of experts cover:

Fracture Toughness explores the effects of specimen size and geometry on constraint, which affects the ability to extract meaningful fracture toughness from small specimens.

Small Size Charpy V-Notch Specimens endeavors to develop correlations between full size specimens and a wide variety of subsized specimen geometries, down to some with cross sections of 1.5 mm x 1.5 mm.

Mechanical Properties describes techniques for extracting mechanical properties from a wide range of materials, including metals and composites.

Small Punch Test describes techniques to obtain mechanical and microstructural data. Two general categories of small punch tests are presented: 1) disk bend tests, where a spherical penetrator deforms a circumferentially-supported disc specimen, and 2) shear punch tests, where a flat-ended cylindrical punch blanks a hole in a clamped coupon specimen

Reconstitution Techniques describes various reconstitution techniques on subsized Charpy V-notch (CVN) specimens, including a large multi-lab European effort (RESQUE--Reconstitution Techniques Qualification and Evaluation Study).

STP 1418 is an important resource for nuclear engineers, materials testing engineers, fracture mechanics professionals, and researchers in engineering of structural components.
Symposium on Radioactivity in Industrial Water and Industrial Waste Water
Authors: ASTM Committee D-19
Published: September 2009

Description

This Symposium volume of seven papers offers a guide to the accurate interpretation of analytical data obtained fro the sampling industrial water and wastes
Measurement of Rock Deformations in Foundations for Mass Concrete Dams
Authors: Rouse George C. , Richardson Joe T. , Misterek Dewayne L.
Published: September 2009

Three types of gages suitable for long-term rock deformation measurements have been developed. These gages were installed in foundation or abutment rock for mass concrete dams. Components of the gages used for indicating rock deformations are mechanical or electrical instruments. The measured results of 24 rock deformation gages having lengths ranging from 20 to 256 feet are reported. These results are used to determine (1) differential settlements beneath gravity structures, (2) deformation moduli of foundation rock, or (3) relative compression in abutment rock.
Measurement of Embankment Stresses on a Hundred-Foot-High Retaining Wall
Authors: Kruse George H.
Published: September 2009

Eight Carlson soil-stress meters measured stresses at the face of a 100 ft-high vertical concrete-core block at the Oroville Dam. The calibration and installation of these gages is discussed briefly. Measurements taken during construction of the 1964 embankment indicate gage readings are reproducible and consistent. Six of the gages were located behind a 20-ft wide, 70-ft thick zone of moderately compacted clay soil. Two were below this area. A disproportionate reduction of stress at the wall behind the “compressible” clay zone illustrates its effectiveness in reducing lateral stresses.
Irradiation Hardening and Embrittlement in Body-Centered Cubic Transition Metals
Authors: Wronski A. S. , Sargent G. A. , Johnson A. A.
Published: September 2009

This paper reviews the literature relating to the hardening and embrittlement of body-centered-cubic transition metals by neutron irradiation near room temperature, and introduces some new results on the dependence of irradiation hardening in molybdenum on neutron dose and strain rate. A critical assessment is made both of the results to be found in the literature and of these new results, and it is concluded that, although we now have a moderately good phenomenological picture of irradiation hardening and embrittlement in these metals, the underlying mechanisms are still obscure. Evidence presently available suggests, however, that for doses up to about 1018 nvt (>1 Mev) these effects are due principally to the pinning of dislocations by point defects, while at higher doses the interaction of moving dislocation with defect clusters and dislocation loops also becomes important.

A summary is given of some recent work carried out by the authors on yielding and flow in several unirradiated body-centered cubic transition metals, especially columbium. The results, which have revealed some new features in the deformation behavior of these metals, should be used in planning future studies of irradiation hardening and embrittlement.
Effects of Irradiation on A302-B Steel Subjected to a Multiaxial Stress Distribution
Authors: Trozera T. A. , Flynn P. W.
Published: September 2009

Changes in mechanical properties of A302-B reactor-grade, pressure-vessel steel due to various combinations of neutron irradiation, biaxial stress fields, and temperature were studied. Capsules containing tube, tension, and Charpy specimens were irradiated to doses from 1.6 x 1018 to 1.14 x 1020 nvt. Results of the Charpy tests are within the well-known scatter band of Steele, Naval Research Laboratory. Tube tests were performed at principal stress ratios of 1:1 and 2:1 at temperatures up to 149 C. The experimental results have been analyzed on the basis of the Hencky-Von Mises strength theory. A reduction of uniform elongation to less than 1 per cent was observed for tubes tested at 66 C, dose about 8 x 1018 nvt, and a stress ratio of 1:1. This should be compared with a uniform strain of 2 1/2 per cent for a tube tested in simple tension under the same conditions of temperature and dosage. The strain predicted from a simple instability criterion is about 2 per cent. The results indicate that the simple geometric methods generally used to predict instability under combined stresses greatly overestimate measured strains for this material. At doses of about 8 x 1019 nvt, yielding of tension bars was followed by large amounts of localized deformation indicating good ductility, but a condition of instability in a pressure vessel application.
Foundry Applications of Radiography
Authors: Cook Earnshaw
Published: September 2009

The cooperation of five X-ray laboratories has made possible the collection of interesting and instructive data concerning the utilization of radiographic examination for metallurgical control and inspection over a wide range of castings. The relative definition of ordinary defects upon the films varies with the general laboratory technique, the type and location of the defect with respect to the direction of the beam and especially with the thickness of the sections. The more familiar imperfections readily interpreted from the films are shrink-age cavities, flocculent shrink, blowholes from mold or metal gases, cracks, inclusions, and pronounced dendritic formations. Arbitrary specifications frequently impose hardships upon the foundry and unnecessarily increase the ultimate cost to the consumer. Maintenance of adequate standards without expensive destructive testing is an outstanding advantage of radiographic inspection. In the laboratories of the Aluminum Company of America, radiography has been used primarily in the development of satisfactory casting or fabricating technique and to a comparatively small extent for the routine inspection of commercial products. The Electro-Alloys Co. and the American Manganese Steel Co. have utilized X-ray examination for similar purposes. The unit at Rock Island Arsenal has been used strictly as an inspection tool. Manufacturers submit sample castings which are radiographed throughout. Complete reports are forwarded to the producer for his information and guidance. The Watertown Arsenal has combined both production and inspection routine as the problems arise. The employment of small-scale pilot castings (175:1 by weight) for the study of homogeneity control and the attainment of directional solidification in production is described in detail.
The Problem of Radiographic Inspection
Authors: Lester H. H.
Published: September 2009

Radiographic acceptance tests set standards of metal soundness that are usually higher than those set by other methods of testing. There are uncertainties of testing that arise from lack of familiarity with the tests, lack of information regarding the physical significance of observed unsoundness, and from various other causes. These uncertainties work to the disadvantage of the producer. The tests are applied properly to three broad classes of structural units: (1) highly stressed units; (2) units that by virtue of the service they perform are very important; (3) units that require expensive machining.

It is difficult to manufacture to standards required by radiographic acceptance tests unless radiography is used in developing the manufacturing technique. There is a present need for better understanding of the tests and their significance on the part of both producers and consumers.
A Million-Volt Portable Radiographic X-ray Unit
Authors: Charlton E. E. , Westendorp W. F.
Published: September 2009

A million-volt portable X-ray unit of small dimensions and light weight is described. Its principal features are: the multisection X-ray tube, the coreless resonance transformer, and the Freon gas insulation. It permits radiography from ten to several hundred times faster than with older equipment through thick masses of steel ranging from ¼ in. to 8 in., producing a radiographic definition of from 1 to 2 per cent.
High-Voltage X-rays in the Boiler Shop
Authors: Carpenter O. R.
Published: September 2009

The development of radiographic equipment for industrial use from the 200-kv. machine of 10 yr. ago, similar in many respects to the medical equipment of that day, to the present million-volt industrial X-ray machine has kept pace with the increasing demands for radiographic examination of heavy wall fusion welded pressure vessels with plate thicknesses up to 52 in. Application of higher-voltage X-ray equipment to industrial radiography introduced the problem of blocking excessive secondary radiation from the film. This requirement was met by the development of the Bucky grid and similar devices. Although a considerable increase in exposure time resulted from the use of these grids, X-ray films of good detail were obtained with 300-kv. and 400-kv. equipment.

The advent of million-volt X-ray equipment with the emission of extremely short wave length X-rays necessitated a radical change in our X-ray technique. A special fine-grained no-screen film (direct-exposure film) was developed for this purpose by the Eastman Kodak Co., representing a significant advancement in the solution of radiographic problems. The use of lead foil screens in conjunction with this film obviates the necessity for Bucky grids and calcium-tungstate screens and permits the standardization of X-ray technique, thus assuring consistently satisfactory results.
A Proposed Method for Determining Percentage of Resin Flow in Preimpregnated Roving
Authors: Rubin Louis
Published: September 2009

Methods currently in use for the determination of the percentage of resin flow in preimpregnated fiber glass roving for filament winding leave much to be desired in ease of test performance and reproducibility of results. A new flow mold and test procedure are proposed which will permit accurate, rapid, and reproducible determination of resin flow. This mold consists of a two-part steel punch and die with which suitable heat and pressure can be applied to resin-impregnated roving specimens, causing the excess resin to flow out axially with respect to the roving. The flowable resin is thus extruded in a measurable form; that is, residual glass or resin flash can be readily weighed. Preliminary laboratory work has indicated that by utilizing this test method, reproducible resin flow determinations can be made wherein the range of individual values is approximately one-half that obtainable by other methods currently in use.
Evaluation of Hoop Tension Tests as a Method of Screening Materials for Filament-Winding Application
Authors: Dallas R. N.
Published: September 2009

The filament-winding technique for the fabrication of pressure vessels has gained wide acceptance in recent years because of the favorable strength to weight ratio that may be achieved with it compared to other methods of fabrication. Additional advantages are the short lead time needed for tool fabrication and the economies that can be realized relative to metal cases for large rocket motor cases.
Preparation and Testing of NOL Rings from Preimpregnated Rovings
Authors: Brown Grant , Davis George E.
Published: September 2009

Most of the original work on filament winding was concerned with wet layup. Now that there is a great tendency to switch to preimpregnated roving the need for adequate test methods has become even greater. The standard method for preparing NOL rings from preimpregnated roving has caused many problems. These problems can be solved by using the cut cylinder method as described in this report. We are currently using this method not only because of its greater accuracy but because ring preparation is greatly simplified. Test results obtained from molded and from cut specimens are compared.
Some Sheet and Bucket Materials for Jet-Engine Application at 1600 F and Higher
Authors: Denny J. P. , Jahnke L. P. , Jones E. S. , Robertshaw F. C.
Published: September 2009

Under certain conditions, higher jet-engine thrust can be obtained by an increase in operating temperatures. The availability of suitable materials for turbine-bucket and sheet-metal parts is one of the factors limiting the extent to which higher operating temperatures can be realized.

In this paper, data on mechanical properties, physical constants, and surface and structural stability are presented, which are believed to be representative of the highest caliber of materials currently available. Other materials exist which have similarly attractive properties. The turbine-bucket materials considered are X-40, HE1049, J-1570, two molybdenum-base alloys (0.3 per cent columbium molybdenum and 0.5 per cent titanium molybdenum), and one cermet (K162B). Sheet alloys considered are Inco 702, Hastelloy C, Incoloy T, and L-605.

For turbine buckets, the nickel- and cobalt-base alloys discussed have properties that make them candidates for application up to possibly 1700 F. The molybdenum and cermet materials appear to have possibilities for application at 1800 F and higher, provided certain inherent disadvantages associated with their use can be overcome.

The sheet alloys discussed can be applied at temperatures up to 2100 F within certain stress and time limitations. For high stress applications involving exposure of sheet metal to temperatures exceeding 1800 F, it will be necessary to resort to cooling, insulative ceramic coatings, or protectivelycoated molybdenum alloy sheet. Though development of the latter is believed to be a considerable way off, it represents the only hope at present for significantly stronger sheet-metal alloys for temperatures in excess of 1800 F.
Status of Ductile Ceramic Research
Authors: Parker Earl R.
Published: September 2009

The prospects for developing strong oxidation-resistant alloys for use at temperatures above approximately 1800 F are not very good. It is highly desirable, therefore, to investigate the potential usefulness of the refractory ceramic compounds for use as structural components. The main drawback with this class of materials is, of course, the tendency to fracture in a brittle manner. Brittleness, however, is not an inherent limitation. As early as 1924, Joffe (1)2 showed that the normally brittle alkali halides could be made to behave in a ductile manner merely by immersing crystals of these salts in warm water while they were being loaded. Joffe explained his results as follows.
Pilot Study on Wind Uplift Resistance of Adhesive Applied Low Slope Roofing Systems
Authors: Baskaran Bas A. , Murty Bona , Tanaka Hiroshi
Published: September 2009

A new generation of built-up roofs, known as Adhesive Applied Roofing Systems (AARS), is gaining popularity in North America for low slope application. AARS use no fasteners for components' attachment and all components (e.g., insulation board, cover board, and membranes) are integrated by application of adhesives. Since there are no metal fasteners, AARS can offer advantages of reduction in moisture migration and thermal bridging. Moisture in the roof envelope can lead generally to material deterioration, structural integrity problems, and the growth of mould. Even though AARS are in commercial use, there is no existing test standard to quantify their wind uplift performance. A new project, “Development of Wind Uplift Standard for Adhesive Applied Low Slope Roofing Systems,” has been initiated in collaboration with industries, university, and the Canadian Government. The project has three major tasks: experimental investigation, formulation of a numerical model, and development of wind design guide and standard. Task 1 completes preliminary investigations by constructing eight mock-ups. All mock-ups had steel deck and polyisocyanurate insulation and varied in adhesives (type, quantity, and application method), cover boards, and membranes. Mock-ups were subjected to both static and dynamic wind loading conditions. Experimental data showed similarity in failure modes and variations in wind uplift ratings. Data show that among the mockups, the weakest link varied depending on the type of adhesives used and component arrangements. This paper presents and discusses the data from this ongoing experimental investigation.
Quality Assurance Program for Soldering Copper Roofs
Authors: Michener Mark L. , Hoernschemeyer Craig A.
Published: September 2009

Since the early 1700s, the art of coppersmithing has been used to construct watertight roofing systems. For low slope, flat seam roofing systems, soldered locked seams and riveted lap joints are essential for the success of this type of system. However, industry standards for testing and monitoring quality assurance to produce a watertight metal roofing product are vague and are not adequately equated to contractor performance. This paper will trace the development of a soldering quality assurance program developed for historical roofing restoration projects requiring watertight seams.The replacement of the original copper roofing on Kingswood School, Cranbrook Educational Community, a National Historic Land-mark in Michigan, serves as a model for this current research. Designed by noted architect Eliel Saarinen and constructed in 1931, the building's extensive copper roof is a character-defining feature of the Prairie Style structure. Because of the importance of the architectural feature, a quality assurance program during reconstruction was necessary to develop a confidence level that performance of the copper roofing would meet or exceed expectations.Procedures were developed for certifying coppersmiths for flat locked and riveted seams. Standardized field observations and reports were created to provide continuous documentation of the contractor's work. Variables examined in the work included joint geometry and soldering necessary for the production of watertight seams. Field observations include solder consumption rates to ensure adequate penetration of the seam.This quality assurance program is designed to identify crucial aspects of a copper roofing system in order to effectively evaluate compliance with design requirements. The program recognizes the need for traditional artistry while incorporating new technology to improve roofing performance. The methodology presented in this paper can be directly employed to develop standards for monitoring copper roof system construction.
Specifications for Roofing and Industrial Asphalts Using Dynamic Shear Rheometry (DSR)
Authors: Baumgardner Gaylon L. , Rowe Geoffrey M.
Published: September 2009

Asphalt specifications in the U.S., Europe, and elsewhere in the world are increasingly dependent upon basic principles of rheology, in particular dynamic shear rheology (DSR). The roofing industry would be benefited by a revised ASTM specification featuring DSR measurements as opposed to the current ASTM Standard Specification D 312 in which softening point is the primary distinguishing characteristic of roofing asphalts. Rheological performance is the critical determinant of satisfactory roofing asphalt quality in that it must possess sufficient stiffness at higher temperatures to resist slippage on slopes and also be flexible enough at lower temperatures to resist cracking and debonding. This paper demonstrates the use of rheological parameters to replace the current softening point parameters, as well as introduces high and low temperature rheological parameters for climatic consideration. The proposed change incorporates climatic performance grades with high and low temperature limits which are based on DSR testing for the basic types of roofing asphalt.
Qualitative Sampling of the Building Envelope for Water Leakage
Authors: Haughton Lonnie L. , Murphy Colin R.
Published: September 2009

Industry standards for intrusive water leakage evaluations of the building envelope are promulgated by ASTM E 2128, “Standard Guide for Evaluating Water Leakage of Building Walls,” which lays out a purposeful step-by-step methodology by which information is accumulated and succeeding sampling locations are identified by a skilled professional; however, some laypersons have criticized building envelope survey findings that are not derived statistically from random sampling. This paper notes that there are relatively few building envelope investigations for which statistical random sampling, in and of itself, is a legitimate or practical methodology for achieving a comprehensive understanding of the sources and mechanisms of water leakage and, therefore, the use of quantitative (i.e., statistical) survey protocols to evaluate the validity of purposeful qualitative sampling of the building envelope is not appropriate. Further, this paper demonstrates that a building envelope evaluation that has been carried out in conformance with ASTM E 2128 satisfies current rules of evidence that require an expert's sampling methodology and analysis to be based upon “scientifically valid” principles. In addition, this paper identifies fundamental assumptions that guide the initial steps of most water leakage evaluations, proposes basic categories for prioritizing the sampling, and discusses the potentially complementary roles of limited surveys by plaintiff and defense experts.