Development of Design Data for Propulsion PMR-15 Composites

The continuing development of PMR-15 composite materials and their associated design properties is pacing the implementation of this technology on commercial aircraft. The guidelines that the FAA has issued regarding the certification of advanced composite structures are very significant with respect to future PMR-15 research and development activities. The FAA has issued an advisory circular dated 1-5-83 concerning guidelines for composite aircraft structures. Of particular significance to PMR-15 technology development is the reliance on combined environmental exposure and component testing, coupled with the stipulation that reliance on previous experience be limited to where common structures and materials have been used for a similar function. Critical environmental exposures for commercial propulsion structures include 50,000 cycle service life, exposure to skydrol, moisture and other fluids, and nacelle fire conditions

Mass killings and detection of impacts

Highly energetic bolide impacts occur and their flux is known. For larger bodies the energy release is greater than for any other short-term global phenomenon. Such impacts produce or release a large variety of shock induced changes including major atmospheric, sedimentologic, seismic and volcanic events. These events must necessarily leave a variety of records in the stratigraphic column, including mass killings resulting in major changes in population density and reduction or extinction of many taxonomic groups, followed by characteristic patterns of faunal and flora replacement. Of these effects, mass killings, marked by large-scale loss of biomass, are the most easily detected evidence in the field but must be manifest on a near-global scale. Such mass killings that appear to be approximately synchronous and involve disappearance of biomass at a bedding plane in many sedimentologically independent sections globally suggest a common cause and probable synchroneity. Mass killings identify an horizon which may be examined for evidence of cause. Geochemical markers may be ephemeral and absence may not be significant. There appears to be no reason why ongoing phenomena such as climate and sea-level changes are primary causes of anomolous episodic events

Managing creative eco-innovation: Structuring outputs from eco-innovation projects

Increasing legislative pressures and consumer awareness of environmentally efficient products are causing businesses to look at Sustainable Product Design (SPD) as an opportunity to improve their products and processes. Business and academia have identified a need for strategic approaches to SPD that will result in ‘step-change’ improvements in the design of products and services. Eco-innovation aims to develop new products and processes which provide customer and business value but significantly decrease environmental impact. Eco-innovation considers environmental aspects of the product at early stages of the New Product Development process. The research presented in this paper looks at the use of eco-innovation tools and focuses on idea generation within ecoinnovation processes. Two novel tools were developed to help review the results from previously conducted eco-innovation workshops: the Standard Design Process Form and the Product Ideas Tree (PIT) diagram. This paper shows the development of these two tools and demonstrates their potential to assist in structuring and documenting ideas throughout the eco-innovation process. The paper discusses the benefits of using such documentation and how it may subsequently improve the management of eco innovation throughout the design process

When Is It Optimal to Delegate: The Theory of Fast-Track Authority

With fast-track authority (FTA), the US Congress delegates trade-policy authority to the President by committing not to amend a trade agreement. Why would it cede such power? We suggest an interpretation in which Congress uses FTA to forestall destructive competition between its members for protectionist rents. In our model: (i) FTA is never granted if an industry operates in the majority of districts; (ii) The more symmetric the industrial pattern, the more likely is FTA, since competition for protectionist rents is most punishing when bargaining power is symmetrically distributed; (iii) Widely disparate initial tari§s prevent free trade even with FTA

Application of Gr/PMR-15 to commercial aircraft

Following from early experience with polyimides on the SST program and Shuttle aft flap studies the Boeing Company is now working on collaborative programs with its principal nacelle suppliers to pursue the development of Gr/PMR-15 nacelle components. Two programs are currently in effect. The first program is directed specifically towards the flight test and service evaluation at the earliest possible date of a 747 nacelle core cowl structure. The second program seeks to firmly establish the producibility and cost of a 757 thrust reverser C duct in a production environment. The near term objectives of these programs include: (1) the comparison of estimated cost and weight of Gr/PMR-15 versus metal structure, (2) the engine test of representative composite structure, (3) the preliminary design and analysis of the C duct structure, and (4) the preparation of cost data and time schedules for the development and producibility program. In addition to powerplant structure, the propulsion ducting system has shown to be a strong candidate for Gr/PMR-15 application. Currently, the Boeing 747 Organization is evaluating the use of PMR-15 matrix composites to replace nearly 800 lbs of titanium ducting per airplane

Fast-Track Authority: A Hold-Up Interpretation.

A central institution of US trade policy is Fast-Track Authority (FT), by whichCongress commits not to amend a trade agreement that is presented to it for ratifica-tion, but to subject the agreement to an up-or-down vote.We offer a new interpretation of FT based on a hold-up problem. If the US gov-ernment negotiates a trade agreement with the government of a smaller economy, asthe negotiations proceed, businesses in the partner economy, anticipating the openingof the US market to their goods, may make sunk investments to take advantage ofthe US market, such as quality upgrades to meet the expectations of the demandingUS consumer. As a result, when the time comes for ratification of the agreement, thepartner economy will be locked in to the US market in a way it was not previously.At this point, if Congress is able to amend the agreement, the partner country hasless bargaining power than it didex ante, and so Congress can make changes that areadverse to the partner. As a result, if the US wants to convince such a partner countryto negotiate a trade deal, it mustfirst commit not to amend the agreementex post.Inthis situation, FT is Pareto-improving

Isolating LCDs at end-of-life using active disassembly technology: A feasibility study

The European Union draft Waste Electrical and Electronic Equipment (WEEE) directive calls for the removal and separate treatment of liquid crystal displays (LCD). This aspect of the legislation will potentially have an important impact upon the future `End of Life' (EoL) processing of much WEEE. Active Disassembly using Smart Materials (ADSM) has been proven to have applicability in self-dismantling, nondestructive and rapid disassembly of small electronic products. This paper investigates the technical feasibility of removing LCD screens from IT communication products using ASDM technology. In this paper an option is suggested to cleanly separate LCD screens from printed circuit boards, utilizing an LCD bracket made from `shape memory polymer'. The case study products employed are Nokia Japanese J-Phones. Demonstration experiments with initial results are presented, and future developments discussed. SMB glass transformation temperatures (Tg) and time efficiency in disassembly are considered

Effect of homogenisation conditions on recrystallisation in the Al-Mg-Mn alloy AA5454

The purpose of the present work is to understand the microstructure development and, particularly, to control the progress of recrystallisation in hot strip in the Al-Mg-Mn alloy AA 5454, which is typically used for the manufacture of structural automotive components. The chemical composition, together with the thermomechanical processing history of this material, has a strong influence on the microstructure of the product and the resulting properties as it is supplied to the customer. Electrical conductivity measurements, thermal analysis and electron microscopy have been carried out to characterise the evolution of precipitation state at various stages in the processing route. The conditions of the homogenisation heat treatment have been varied, and the effect on subsequent recrystallisation after hot rolling has been evaluated in both the as cast and rough rolled condition by optical microscopy techniques. Results indicate that the conditions of homogenisation heat treatment and roughing rolling are critical for the generation of a suitable recrystallised microstructure in AA 5454 hot strip. A new two stage homogenisation practice has been developed to expedite post-rolling recrystallisation in this alloy

Two-photon optics of Bessel-Gaussian modes

In this paper we consider geometrical two-photon optics of Bessel-Gaussian modes generated in spontaneous parametric down-conversion of a Gaussian pump beam. We provide a general theoretical expression for the orbital angular momentum (OAM) spectrum and Schmidt number in this basis and show how this may be varied by control over the radial degree of freedom, a continuous parameter in Bessel-Gaussian modes. As a test we first implement a back-projection technique to classically predict, by experiment, the quantum correlations for Bessel-Gaussian modes produced by three holographic masks, a blazed axicon, binary axicon and a binary Bessel function. We then proceed to test the theory on the down-converted photons using the binary Bessel mask. We experimentally quantify the number of usable OAM modes and confirm the theoretical prediction of a flattening in the OAM spectrum and a concomitant increase in the OAM bandwidth. The results have implications for the control of dimensionality in quantum states.Comment: 8 pages, 10 figure