3,011 research outputs found
Developing a current capability design for a manufacture framework in the aerospace industry
During progressive product design and development in the aerospace industry, a lack of
effective communication between the sequential functions of design, manufacturing and
assembly causes delays and setbacks whereby production capabilities are unable to
realise design intent in high-complexity product models. There is a need to formalise
the progressive design and release of an engineering model to production functions
during New Product Introduction (NPI) via defining key stages of definition maturity
and information requirements through a structured process.
This research develops a framework to facilitate optimal Design for Manufacture and
Assembly (DfMA) based on current manufacturing capabilities within the aerospace
industry, promoting effective knowledge management at all stages of design definition.
The framework was developed through the accomplishment of a series of objectives: (1)
Investigate optimal DfMA principles and process capability analysis through a
comprehensive literature review, (2) capture the current practice of progressive drawing
release in the aerospace and automotive sectors, (3) create a route map of the release
process built around the optimal critical path, (4) define roles and procedures to follow
at each stage and (5) validate the proposed process framework through expert opinion.
These objectives were achieved through the adoption of a four-stage qualitative
methodology.
The framework promotes the understanding and identification of the major stages,
activities, responsibilities and information requirements throughout a structured design
release process where quantified manufacturing capability data is incorporated within
early design definition activities. Adherence to the process route-map ensures that no
engineering model is released that cannot be realised by manufacturing and assembly
functions. This facilitates the efficient organisation of information on an optimal
concurrent engineering platform, leading to a reduction in product development leadtimes
and re-work through informed design.SAS Prize winne
The in vivo effect of hepatotrophic factors ALR, HGF, and IGF-II on natural killer cell functions
Use of ERTS data for a multidisciplinary analysis of Michigan resources
The author has identified the following significant results. The results of this investigation of ratioing simulated ERTS spectral bands and several non-ERTS bands (all collected by an airborne multispectral scanner) indicate that significant terrain information is available from band-ratio images. Ratio images, which are based on the relative spectral changes which occur from one band to another, are useful for enhancing differences and aiding the image interpreter in identifying and mapping the distribution of such terrain elements as seedling crops, all bare soil, organic soil, mineral soil, forest and woodlots, and marsh areas. In addition, the ratio technique may be useful for computer processing to obtain recognition images of large areas at lower costs than with statistical decision rules. The results of this study of ratio processing of aircraft MSS data will be useful for future processing and evaluation of ERTS-1 data for soil and landform studies. Additionally, the results of ratioing spectral bands other than those currently collected by ERTS-1 suggests that some other bands (particularly a thermal band) would be useful in future satellites
Aspects of the Life History of the Tadpole Madtom, Noturus gyrinus (Siluriformes: Ictaluridae), in Southern Illinois
Author Institution: Department of Zoology, Southern Illinois University at CarbondaleAspects of the life history of Noturus gyrinus were studied from collections and observations made at Dutchman Creek, Johnson County, Illinois, between 25 October 1982 and 21 April 1984, and from specimens collected from Silver and Sugar creeks, Clinton, Madison, and St. Clair counties, Illinois, in July and August, 1982. N. gyrinus grew in length at a decreasing rate and in weight at a nearly constant rate for at least three (females) or four years (males). The largest individuals observed were a 97.5-mm standard length (SL) male and a 78.1-mm SL female. Mean annual SL was not significantly different between sexes except that males were both longer and heavier than females at age 3 + . There were 4.5 times as many males as females at age 3+, although the overall sex ratio was nearly 1:1 in the total sample. Only 29% survived past their first year; 90.5% did not live past their second year. Individuals (78%) usually matured in two years (sexes combined), although about 5% of males and 17% of females matured in one year. Mature males were 55-mm SL or longer, and mature females 48-mm or longer at one year. Mature females examined for the presence of eggs ranged from 52.6 to 78.9-mm SL, and contained 48 to 323 (x = 151.3) mature ova. Lengths and weights of mature females 'were both significant (P < 0.05) predictors of the numbers of mature ova. Dipteran larvae (chironomids) and small crustaceans (mainly isopods) constituted the major portion of the annual diet of all size classes. Gut contents of five species of piscivorous fish were examined; no evidence of predation on N. gyrinus was found
Why do many pheasants released in the UK die, and how can we best reduce their natural mortality?
This is the final version of the article. Available from Springer Verlag via the DOI in this record.Around 60% of pheasants released for shooting in the UK, an estimated 21 million birds, do not end up at their intended fate: being shot. This constitutes wastage, raising economic, environmental and ethical questions. We review what is known of the fates of released pheasants and consider why they do not directly contribute to the numbers harvested. We focus on four main explanations: predation, disease, starvation and dispersal, and highlight other important causes of mortality. For each explanation, we attempt to attribute levels of loss and identify timings or conditions when such losses may be heaviest. We review factors that exacerbate losses and methods available to mitigate them. Opportunities for amelioration may arise at all stages of the rearing and release of pheasants and involve changes to the conditions under which eggs are produced, the way young pheasants are reared or the management of the environment into which they are released. We found few studies investigating impacts of post-release management techniques on pheasant survival outside of the breeding season within a UK context. We found that a number of less commonly deployed practices focusing on early-life, pre-release management may improve survival. Given the scale of pheasant releasing in the UK, even improvements in survival of 1% would mean that ~ 350,000 fewer birds die of natural causes. Complementing current post-release management with proven novel pre-release management interventions could reduce the number of pheasants required for release, whilst maintaining current shooting levels. Lowering release numbers would lower financial costs, benefit the environment and reduce some ethical concerns over the release and shooting of reared pheasants
Aharanov-Bohm excitons at elevated temperatures in type-II ZnTe/ZnSe quantum dots
Optical emission from type-II ZnTe/ZnSe quantum dots demonstrates large and
persistent oscillations in both the peak energy and intensity indicating the
formation of coherently rotating states. Furthermore, the Aharanov-Bohm (AB)
effect is shown to be remarkably robust and persists until 180K. This is at
least one order of magnitude greater than the typical temperatures in
lithographically defined rings. To our knowledge this is the highest
temperature at which the AB effect has been observed in semiconductor
structures
Serial monitoring of immunologic function and phenotype of lymphocytes in the blood of transplanted patients randomized to cyclosporine or FK 506
Sex-specific fundamental and formant frequency patterns in a cross-sectional study
An extensive developmental acoustic study of the speech patterns of children and adults was reported by Lee and colleagues [Lee et al., J. Acoust. Soc. Am. 105, 1455-1468 (1999)]. This paper presents a reexamination of selected fundamental frequency and formant frequency data presented in their report for 10 monophthongs by investigating sex-specific and developmental patterns using two different approaches. The first of these includes the investigation of age- and sex-specific formant frequency patterns in the monophthongs. The second, the investigation of fundamental frequency and formant frequency data using the critical band rate (bark) scale and a number of acoustic-phonetic dimensions of the monophthongs from an age- and sex-specific perspective. These acoustic-phonetic dimensions include: vowel spaces and distances from speaker centroids; frequency differences between the formant frequencies of males and females; vowel openness/closeness and frontness/backness; the degree of vocal effort; and formant frequency ranges. Both approaches reveal both age- and sex-specific development patterns which also appear to be dependent on whether vowels are peripheral or non-peripheral. The developmental emergence of these sex-specific differences are discussed with reference to anatomical, physiological, sociophonetic and culturally determined factors. Some directions for further investigation into the age-linked sex differences in speech across the lifespan are also proposed
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