bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Rare Earth Additions on the High-Temperature Properties of a Cobalt-Base Alloy
Authors: Breen J. E. , Lane J. R. 
Published: September 2009

Improvements in the high-temperature mechanical properties of a typical cobalt-base alloy were achieved by the addition of rare earths as misch metal. Three alloys of the same base composition but with 0 to 2 per cent rare earth added were cast from a split heat. Stress-rupture tests were run at 1500, 1600, and 1700 F.
The high-temperature strength as well as ductility were increased in both as-cast and aged material at all temperatures, with the greatest benefit occurring at 1500 F. No improvements in room temperature tensile properties were noted.
Titanium-Carbide Products Produced by the Infiltration Technique
Authors: Skolnick Leonard P. , Goetzel Claus G. 
Published: September 2009

Work conducted on a metal-bonded titanium-carbide material made by the infiltration technique shows impact strength superior to the conventional cemented titanium-carbide materials. A fine isolated carbide phase seems to provide improved toughness, and the infiltration process appears capable of producing such a structure. Stress-rupture properties compare quite favorably with those of Alloy X-40. At 1800 F at a stress of 15,000 psi, the life of some of the infiltrated titanium-carbide grades is over 1000 times that of cast X-40.
Processwise, the infiltration technique permits the use of low pressures for compacting the powders, making possible direct pressing of complex shapes. The infiltration per se permits the production of void free bodies of remarkably true shape and close dimensional tolerances, and in many aspects is strikingly similar to precision casting.
Infiltrated titanium-carbide products may very well prove to be excellent high-temperature materials for use above 1600 F.
Thermal Fatigue Testing of Sheet Metal
Authors: Lardge H. E. 
Published: September 2009

The paper is concerned with the thermal fatigue testing of sheet metal carried out over a number of years. The test program was first embarked upon when cracks, which were not thought to be due entirely to mechanical fatigue, were found at the edges of holes in sheet-metal flame tubes.
A thermal fatigue test was devised based on heating a test specimen with a central hole to 1650 F and then cooling it rapidly in a blast of cold air. The thermal cycle was based on the temperature curve taken on a flame tube on an engine during accelerating and decelerating conditions.
The early work was concerned with Nimonic 75—a nickel-chromium alloy used for flame tubes on most British engines—and showed the relationship between increasing thickness of sheet and thermal fatigue life and also the temperature-life relationship of this material. The program was then widened to include other nickel-base alloys; austenitic and duplex stainless steels; mild and low-alloy steels (protected from corrosion); and laminated materials.
Thermal Shock Testing of High-Temperature Metallic Materials
Authors: Hunter Thomas A. 
Published: September 2009

A program of investigation has been undertaken to evaluate the resistance of various materials to thermal shock. A preliminary analysis of thermalshock damage has been carried out on a theoretical basis. The results of this theoretical work indicate that the scope of the problem is so wide that purely analytical methods must be supplemented by experimental data.
An experimental program has, therefore, been set up, and fifteen selected materials have been tested. These include types 304, 310, and 347 stainless steels, K151A and K152B cermets, N-155, cast and wrought S-816, Waspalloy, Hastelloy C, Inconel, Nimonic 80-A, M-252, cast HS-21, and Battellalloy. Suitable apparatus has been constructed which gives reasonable reproducibility of results. A standard specimen shape has been devised after considerable experimentation. Excursions into the subjects of previous specimen history, mechanical fatigue, and thermal wiggling have been made.
Comparative evaluations for the fifteen materials have been made for temperatures between 1600 F and 2000 F.
Laboratory Evaluation of Nichrome-Foil Strain Gage Installations Up to 1200 F
Authors: Forlifer William R. 
Published: September 2009

An experimental program was conducted recently at The Martin Co. to explore the problem areas associated with strain measurement up to 1200 F. The areas included bonding techniques, temperature compensation methods, effects of temperature cycling and sensitivity variations. Tests were conducted on cantilever stainless steel specimens.
The results indicate that temperature cycling has a significant effect on the strain-gage reading under no-load conditions. Possible errors are presented both for the temperature effect on the no-load strain reading and for the variation of sensitivity with temperature.
Ceramic Coatings for Experimental Stress Analysis
Authors: Stern F. B. 
Published: September 2009

This paper presents a brief history and development of resin-base brittle coatings for experimental stress analysis. These coatings have been in use for a number of years but are limited in operation to temperatures up to approximately 100 F.
A new series of ceramic-based materials has been developed which will operate from approximately —50 to 600 F in a sensitivity range of 200 to 1800 microinches, depending on the coefficient of expansion of the steel on which the coating is applied. These ceramic brittle coatings permit experimental stress analysis on steel parts up to 600 F.
Neither the presence of oil and high humidity, nor slow application of loads affect the test results. Dynamic tests may be conducted with the ceramic coatings in areas where abrasion by air or dust would prevent use of the resin-base materials. Tests may be conducted out of doors for indefinite time intervals. Thermal strains can now be measured by these brittle coatings.
Some illustrations are given of the use of the ceramic coatings to measure stresses on a gas turbine rotor.
Problems in Thermal Stress Measurements
Authors: DeMichele D. J. 
Published: September 2009

Problems requiring experimental determination of stresses in structures subjected to high temperature environments can be categorized as problems in which it is necessary to determine:
1. Vibratory stresses only (static stresses on which vibratory stresses are superimposed are ignored).
2. Stresses caused by external loads applied over relatively long time intervals in high, but constant, positive temperature environments.
3. Stresses in structures which may or may not be subjected to external loads but which occur in environments characterized by temperature distributions varying in space and with time.
Effects of High Pressure and Temperature on the Mechanical Properties of Metals and Alloys
Authors: Radcliffe S. V. 
Published: September 2009

The application of high pressure to metals and alloys can cause changes to their structures and mechanical properties observed subsequently. The nature and magnitude of these changes depends primarily on such factors as the type of material and its initial structure, the nature and magnitude of the pressure applied (static or dynamic), the types of phase transformation or precipitation induced by changes in pressure at constant temperature (abaric transformation) or in temperature at constant pressure (athermal transformation and quenching followed by isothermal transformation), and the accidental introduction of plastic distortion during the pressure cycle.
The contributions and interrelationships of these various factors are discussed for different metals—in particular, iron and some alloys of iron. Attention is given to the effects of crystalline anisotropy, changes in phase equilibria and reaction kinetics, quasi-hydrostatic pressure conditions, and shock-induced imperfections.
The Sheltered Genetic Load Linked to the S Locus in Plants: New Insights From Theoretical and Empirical Approaches in Sporophytic Self-Incompatibility
Authors: Llaurens Violaine , Gonthier Lucy , Billiard Sylvain 
Published: September 2009

Abstract
Inbreeding depression and mating systems evolution are closely linked, because the purging of deleterious mutations and the fitness of individuals may depend on outcrossing vs. selfing rates. Further, the accumulation of deleterious mutations may vary among genomic regions, especially for genes closely linked to loci under balancing selection. Sporophytic self-incompatibility (SSI) is a common genetic mechanism in angiosperm that enables hermaphrodite plants to avoid selfing and promote outcrossing. The SSI phenotype is determined by the S locus and may depend on dominance relationships among alleles. Since most individuals are heterozygous at the S locus and recombination is suppressed in the S-locus region, it has been suggested that deleterious mutations could accumulate at genes linked to the S locus, generating a “sheltered load.” In this article, we first theoretically investigate the conditions generating sheltered load in SSI. We show that deleterious mutations can accumulate in linkage with specific S alleles, and particularly if those S alleles are dominant. Second, we looked for the presence of sheltered load in Arabidopsis halleri using CO2 gas treatment to overcome self-incompatibility. By examining the segregation of S alleles and measuring the relative fitness of progeny, we found significant sheltered load associated with the most dominant S allele (S15) of three S alleles tested. This sheltered load seems to be expressed at several stages of the life cycle and to have a larger effect than genomic inbreeding depression.
TEN1Is Essential forCDC13-Mediated Telomere Capping
Authors: Xu Ling , Petreaca Ruben C , Gasparyan Hovik J , Vu Stephanie , Nugent Constance I 
Published: September 2009

AbstractTelomere binding proteins protect chromosome ends from degradation and mask chromosome termini from checkpoint surveillance. In Saccharomyces cerevisiae, Cdc13 binds single-stranded G-rich telomere repeats, maintaining telomere integrity and length. Two additional proteins, Ten1 and Stn1, interact with Cdc13 but their contributions to telomere integrity are not well defined. Ten1 is known to prevent accumulation of aberrant single-stranded telomere DNA; whether this results from defective end protection or defective telomere replication is unclear. Here we report our analysis of a new group of ten1 temperature-sensitive (ts) mutants. At permissive temperatures, ten1-ts strains display greatly elongated telomeres. After shift to nonpermissive conditions, however, ten1-ts mutants accumulate extensive telomeric single-stranded DNA. Cdk1 activity is required to generate these single-stranded regions, and deleting the EXO1 nuclease partially suppresses ten1-ts growth defects. This is similar to cdc13-1 mutants, suggesting ten1-ts strains are defective for end protection. Moreover, like Cdc13, our analysis reveals Ten1 promotes de novo telomere addition. Interestingly, in ten1-ts strains at high temperatures, telomeric single-stranded DNA and Rad52-YFP repair foci are strongly induced despite Cdc13 remaining associated with telomeres, revealing Cdc13 telomere binding is not sufficient for end protection. Finally, unlike cdc13-1 mutants, ten1-ts strains display strong synthetic interactions with mutations in the POLα complex. These results emphasize that Cdc13 relies on Ten1 to execute its essential function, but leave open the possibility that Ten1 has a Cdc13-independent role in DNA replication.
Impact of Changes in Serum Sodium Levels on 2-Year Neurologic Outcomes for Very Preterm Neonates
Authors: Baraton Louis , Ancel Pierre Yves , Flamant Cyril , Orsonneau Jean Luc , Darmaun Dominique , Rozé Jean Christophe 
Published: September 2009

OBJECTIVE: The goal was to analyze the relationship between changes in serum sodium levels during the first month of life and impaired functional outcomes at 2 years of age for very preterm infants.
METHODS: All very preterm infants who were born at &lt;33 weeks of gestation between January 1, 2003, and July 31, 2004, were hospitalized in the NICU, and survived to discharge were included in this study. Changes in serum sodium levels were measured, and infants were evaluated at corrected age of 2 years.
RESULTS: The analysis involved 237 patients, for whom 3927 serum sodium determinations were performed during the first month of life. We defined 3 tertiles of changes in serum sodium levels. A total of 84 infants demonstrated small changes in serum sodium levels (&lt;8 mEq/L), 86 demonstrated large changes (8–13 mEq/L), and 67 demonstrated very large changes (&gt;13 mEq/L). The reference group was represented by the first tertile. At 2 years of age, large and very large changes in serum sodium levels were significantly associated with risk of impaired functional outcomes, after adjustment for gestational age and perinatal and neonatal hospitalization characteristics (large changes: odds ratio: 3.5 [95% confidence interval: 1.1–11.8]; P = .04; very large changes: odds ratio: 5.1 [95% confidence interval: 1.3–13.6]; P = .02).
CONCLUSIONS: Although large and very large changes in serum sodium levels may simply reflect the severity of illness and/or the quality of care, a causal relationship with outcomes cannot be excluded. Cautious fluid and electrolyte management is recommended for very premature infants.
Sugar-coaters and Straight Talkers: Communicating About Developmental Delays in Primary Care
Authors: Sices Laura , Egbert Lucia , Mercer Mary Beth 
Published: September 2009

OBJECTIVES: The goals were to investigate parents' and early intervention (EI) specialists' beliefs and experiences regarding discussing child development in primary care and to identify communication barriers and opportunities.METHODS: Focus groups were held with (1) mothers of young children with typical development, (2) mothers of young children who received EI services, and (3) EI specialists. Seven groups (N = 46 participants) were conducted in the greater Cleveland, Ohio, area. Meetings were audio-recorded, transcribed, coded, and analyzed, to identify themes.RESULTS: Most mothers reported a preference for a nonalarmist style of communication when developmental delays are suspected. In contrast, some mothers preferred a more direct style, including the use of labels to help them understand their child's development. The importance of preparation to accept information about developmental delays emerged as a theme in all groups. Elements contributing to preparedness included information about expected developmental skills, suggestions for promoting skills, and a specific time frame for follow-up evaluation. Mothers of children with disabilities perceived that early reassurance of normalcy by providers in response to their concerns led to self-doubt and increased difficulty accepting the diagnosis.CONCLUSIONS: Mothers and EI specialists have clear ideas about factors that promote or impede communication regarding child development. This information can inform primary care providers' approaches to monitoring and screening the development of young children and to communicating with parents regarding suspected developmental delays.
Ethics and Professionalism in the Pediatric Curriculum: A Survey of Pediatric Program Directors
Authors: Lang Colleen Walsh , Smith Peter J. , Ross Lainie Friedman 
Published: September 2009

OBJECTIVE: Since 1982, pediatric residency programs have been asked to evaluate trainees for ethical behavior. In 2007, the Accreditation Council for Graduate Medical Education required documenting teaching and evaluation of professionalism. Pediatric residency program directors were surveyed to ascertain what they know about the content and process of their ethics and professionalism curricula.METHODS: From February to May 2008, 394 program directors from the Association of Pediatric Program Directors were surveyed.RESULTS: Of 386 eligible survey respondents, 233 (60%) returned partial or complete surveys. Programs were evenly divided on whether ethics was taught as an organized curriculum or integrated. Professionalism was combined with the ethics curriculum in 27% of programs and taught independently in 38% of programs, but 35% had no professionalism curriculum. More than one third of the respondents did not answer each content and structure question. Approximately two thirds of those who responded stated that their program dedicated &lt;10 hours per year to ethics and professionalism, respectively. Nearly three fourth of programs identified crowding of the curriculum and one third identified lack of faculty expertise as curricular constraints. Respondents expressed interest in more curricular materials from the American Board of Pediatrics or Association of Pediatric Program Directors.CONCLUSIONS: Despite requirements to train and evaluate residents in ethics and professionalism, there is a lack of structured curriculum, faculty expertise, and evaluation methodology. Effectiveness of training curricula and evaluation tools need to be assessed if the Accreditation Council for Graduate Medical Education requirements for competencies in these areas are to be meaningfully realized.
Use of Hyperspectral Remote Sensing to Evaluate Efficacy of Aquatic Plant Management
Authors: Santos Maria J. , Khanna Shruti , Hestir Erin L. , Andrew Margaret E. , Rajapakse Sepalika S. , Greenberg Jonathan A. , Anderson Lars W. J. , Ustin Susan L. 
Published: September 2009

AbstractInvasive aquatic weeds negatively affect biodiversity, fluvial dynamics, water quality, and water storage and conveyance for a variety of human resource demands. In California's Sacramento–San Joaquin River Delta, one submersed species—Brazilian egeria—and one floating species—waterhyacinth—are actively managed to maintain navigable waterways. We monitored the spatial and temporal dynamics of these species and their communities in the Sacramento-San Joaquin River Delta using airborne hyperspectral data and assessed the effect of herbicide treatments used to manage these species from 2003 to 2007. Each year, submersed aquatic plant species occupied about 12% of the surface area of the Delta in early summer and floating invasive plant species occupied 2 to 3%. Since 2003, the coverage of submersed aquatic plants expanded about 500 ha, whereas the coverage of waterhyacinth was reduced. Although local treatments have reduced the coverage of submersed aquatic plants, Delta-wide cover has not been significantly reduced. Locally, multiyear treatments could decrease submersed aquatic plants spread, given that no residual plants outside the treated area were present. In contrast, the spread of waterhyacinth either has been constant or has decreased over time. These results show that (1) the objectives of theEgeria densaControl Program (EDCP) have been hindered until 2007 by restrictions imposed on the timing of herbicide applications; (2) submersed aquatic plants appeared to function as ecosystem engineers by enabling spread to adjacent areas typically subject to scouring action; (3) repeated herbicide treatment of waterhyacinth has resulted in control of the spread of this species, which also appears to have facilitated the spread of waterprimrose and floating pennywort. These results suggest that management of the Delta aquatic macrophytes may benefit by an ecosystem-level implementation of an Integrated Delta Vegetation Management and Monitoring Program, rather than targeting only two problematic species.
Invasive White Sweetclover (Melilotus officinalis) Control with Herbicides, Cutting, and Flaming
Authors: Conn Jeffery S. , Seefeldt Steven S. 
Published: September 2009

AbstractWhite sweetclover is invading the Alaska glacial river floodplains and roadsides adjacent to natural areas, and control methods are needed. Chlorsulfuron, 2,4-DB, clopyralid, triclopyr, and 2,4-D controlled white sweetclover seedlings below recommended rates in the greenhouse. Biomass of established plants in the field was reduced by chlorsulfuron at recommended (17.6 g ai/ha), 1/2, and 1/4 rates and was reduced by triclopyr and 2,4-D at recommended rates (1,260 and 1,600 g ai/ha). Herbicides were more effective at reducing white sweetclover viable seed production in 2007 than in 2006. Only chlorsulfuron at 17.6 g ai/ha (recommended rate) eliminated seed production in both years. Flaming killed first-year plants, but some second-year plants resprouted and produced viable seed. Cutting at the 2.5 or 10 cm height did not control first-year plants because of regrowth, and second-year plant density and seed production was reduced by cutting at 2.5 cm but not by cutting at 10 cm.
Distinct Effects of Leptin and a Melanocortin Receptor Agonist Injected Into Medial Hypothalamic Nuclei on Glucose Uptake in Peripheral Tissues
Authors: Toda Chitoku , Shiuchi Tetsuya , Lee Suni , Yamato-Esaki Maya , Fujino Yusuke , Suzuki Atsushi , Okamoto Shiki , Minokoshi Yasuhiko 
Published: September 2009

OBJECTIVE
The medial hypothalamus mediates leptin-induced glucose uptake in peripheral tissues, and brain melanocortin receptors (MCRs) mediate certain central effects of leptin. However, the contributions of the leptin receptor and MCRs in individual medial hypothalamic nuclei to regulation of peripheral glucose uptake have remained unclear. We examined the effects of an injection of leptin and the MCR agonist MT-II into medial hypothalamic nuclei on glucose uptake in peripheral tissues.

RESEARCH DESIGN AND METHODS
Leptin or MT-II was injected into the ventromedial (VMH), dorsomedial (DMH), arcuate nucleus (ARC), or paraventricular (PVH) hypothalamus or the lateral ventricle (intracerebroventricularly) in freely moving mice. The MCR antagonist SHU9119 was injected intracerebroventricularly. Glucose uptake was measured by the 2-[3H]deoxy-d-glucose method.

RESULTS
Leptin injection into the VMH increased glucose uptake in skeletal muscle, brown adipose tissue (BAT), and heart, whereas that into the ARC increased glucose uptake in BAT, and that into the DMH or PVH had no effect. SHU9119 abolished these effects of leptin injected into the VMH. Injection of MT-II either into the VMH or intracerebroventricularly increased glucose uptake in skeletal muscle, BAT, and heart, whereas that into the PVH increased glucose uptake in BAT, and that into the DMH or ARC had no effect.

CONCLUSIONS
The VMH mediates leptin- and MT-II–induced glucose uptake in skeletal muscle, BAT, and heart. These effects of leptin are dependent on MCR activation. The leptin receptor in the ARC and MCR in the PVH regulate glucose uptake in BAT. Medial hypothalamic nuclei thus play distinct roles in leptin- and MT-II–induced glucose uptake in peripheral tissues.