8,528 research outputs found

    Study of high performance alloy electroforming

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    Nickel-manganese electroformed specimens and nickel-cobalt-manganese samples were heat treated at 343 C (650 F) for comparison of room temperature ductility with that observed for alloys heat treated at 315.6C (600 F). All heat treatments were for 24 hours. This heat treatment temperature increase generally did not result in significant improvements in ductility. However, increases in yield strength - with slight decreases in tensile strengths - were noted for the nickel-manganese and nickel-cobalt-manganese alloys. For the case of employing fairly high manganese contents in the electrolyte and countering ensuing high tensile stress in the alloy by saccharin additions to the bath, it was noted that nickel-manganese alloys with over 0.4% by weight manganese retained high ultimate and yield strengths after the 343 C (650 F) heat treatment for 24 hours. Elongations were still lower than desired. For alloys with less than 0.4% by weight manganese this heat treatment provided excellent ductility, but very significant reductions in ultimate and yield strengths were noted

    Study of high performance alloy electroforming

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    Using the two nickel-manganese alloy electroforming baths of near identical compositions, panels were electroformed under the same deposition parameters of current density, bath temperature, pH, and pulse plating conditions of duty cycle and frequency. By changing the electrolyte agitation conditions, significant effects on mechanical properties were noted. Since electrolyte agitation conditions on the typical flat panels studied to date will not be identical to those existing on a complex curved shape such as the SSME combustion chamber simulation, it is most important that these effects be evaluated prior to Phase B studies. The subscale chamber has been fabricated and shield support tooling is being made. Electroforming of optimized alloy test bars is being deferred until the electrolyte agitation effects are more fully appraised

    Study of high performance alloy electroforming

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    The first series of heat treated nickel manganese alloys are tested for mechanical properties at temperatures of 148.9 C (300 F) and 260 C (500 F). All material receives the same heat treatment in order to provide a common basis for comparison of results. Mechanical property performance improves with increasing manganese content in the alloy. Although all manganese bearing alloy is significantly superior to conventional electroformed nickel, samples containing over 3000 ppm manganese display outstanding ultimate and yield strengths while maintaining reasonably satisfactory ductility. Alloy containing over 6000 ppm of manganese is very competitive to Inconel 718 (mill annealed and age hardened) at all temperatures of interest, although ductility is not as great in the electrodeposited counterpart

    The concept of sexual exploitation in legislation relating to persons with intellectual disability

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    The focus of this paper is on the use of the concept of sexual exploitation in legislation concerning sexual expression by persons with mental impairment, with particular emphasis on persons with intellectual disability. Two main statutory approaches have been adopted in Australian jurisdictions. The first is prohibition of sexual acts between a person with intellectual disability and others who, by virtue of their employment, are in a position of ascendancy over that person. The second is the prohibition of sexually exploitative acts by any person towards a person with an intellectual disability. The major aim in this article is to critically examine these approaches and evaluate them according to the standards of being non-discriminatory, minimally restrictive of rights, and enforceable. It is argued that comprehensively cataloguing sexually exploitative acts is untenable, with the result that prohibition of all sexual exploitation is unenforceable. The alternative, namely legislation that prohibits sexual relations with any person employed to render any kind of service to the intellectually disabled person, would further restrict an already limited number of potential sexual partners. We suggest that a more useful approach would be to prohibit sexual activity in one-on-one relationships whose scope is commonly understood to exclude such acts, while allowing relations between workers or caregivers and the persons to whom they do not directly render services. This mechanism would have to be narrowly defined to have the desired effect of affording protection to vulnerable persons while preserving their right to sexual expression

    Development of a Cone Penetrometer for Measuring Spectral Characteristics of Soils in Situ

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    A patent was recently granted to the U.S. Army for an adaptation of a soil cone penetrometer that can be used to measure the spectral characteristics (fluorescence or reflectance) of soils adjacent to the penetrometer rod. The system can use a variety of light sources and spectral analytical equipment. A laser induced fluorescence measuring system has proven to be of immediate use in mapping the distribution of oil contaminated soil at waste disposal and oil storage areas. The fiber optic adaptation coupled with a cone penetrometer permits optical characteristics of the in-situ soil to be measured rapidly, safely, and inexpensively. The fiber optic cone penetrometer can be used to gather spectral data to a depth of approximately 25 to 30 m even in dense sands or stiff clays and can investigate 300 m of soil per day. Typical detection limits for oil contamination in sand is on the order of several hundred parts per million

    Using the interpersonal reactivity index to assess empathy in violent offenders

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    The Interpersonal Reactivity Index (IRI), developed by Davis (1980), provides an excellent multidimensional measure of empathy for the general adult population, the domain for which it was developed. Its use has subsequently expanded into other areas, for example criminal psychology. In this domain empathy is a critical variable in theoretical accounts of criminality and particularly of violence. For many researchers within the field of criminal psychology, the IRI has become the instrument of choice for the assessment of empathy. However, the psychometric properties of the scale, when used with a criminal population, have not been investigated. This paper reports the results of an investigation into the reliability and component structure of the IRI using a sample of violent offenders. The Personal Distress subscale was found not to be reliable when used in an offender population. Furthermore, when used to assess offenders, principle components analysis did not confirm the four-subscale structure of the IRI. Possible explanations for these findings are discussed in relation to offender assessment in general

    High performance alloy electroforming

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    Electroformed copper and nickel are used in structural applications for advanced propellant combustion chambers. An improved process has been developed by Bell Aerospace Textron, Inc. wherein electroformed nickel-manganese alloy has demonstrated superior mechanical and thermal stability when compared to previously reported deposits from known nickel plating processes. Solution chemistry and parametric operating procedures are now established and material property data is established for deposition of thick, large complex shapes such as the Space Shuttle Main Engine. The critical operating variables are those governing the ratio of codeposited nickel and manganese. The deposition uniformity which in turn affects the manganese concentration distribution is affected by solution resistance and geometric effects as well as solution agitation. The manganese concentration in the deposit must be between 2000 and 3000 ppm for optimum physical properties to be realized. The study also includes data regarding deposition procedures for achieving excellent bond strength at an interface with copper, nickel-manganese or INCONEL 718. Applications for this electroformed material include fabrication of complex or re-entry shapes which would be difficult or impossible to form from high strength alloys such as INCONEL 718

    Nondestructive tests of regenerative chambers

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    The capabilities and limitations of nondestructive evaluation methods were studied to detect and locate bond deficiencies in regeneratively cooled thrust chambers for rocket engines. Flat test panels and a cylinder were produced to simulate regeneratively cooled thrust chamber walls. Planned defects with various bond integrities were produced in the panels to evaluate the sensitivity, accuracy, and limitations of nondestructive methods to define and locate bond anomalies. Holography, acoustic emission, and ultrasonic scan were found to yield sufficient data to discern bond quality when used in combination and in selected sequences. Bonding techniques included electroforming and brazing. Materials of construction included electroformed nickel bonded to Nickel 200 and OFHC copper, electroformed copper bonded to OFHC copper, and 300 series stainless steel brazed to OFHC copper. Variations in outer wall strength, wall thickness, and defect size were evaluated for nondestructive test response
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