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

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

An Exploration of the Performance and Acoustic Characteristics of UAV-Scale Stacked Rotor Configurations

As interest grows in rotor- and propeller-driven electric vertical takeoff and landing (eVTOL) aircraft for the Urban Air Mobility market, there is a potential for previously studied concepts to reemerge due to the opportunities afforded by novel technologies and operating modes. One such concept is the stacked rotor, which consists of multiple co-rotating rotors positioned co-axially with a small axial offset. The goal of the work presented in this paper is to determine whether stacked rotors offer a compelling advantage for eVTOL aircraft in terms of both performance and acoustic characteristics. Results are presented for new experimental tests and computational modeling of multiple stacked rotor configurations, and comparisons are made with conventional rotor configurations. Testing of thirteen separate configurations each using the same blade shaperevealed a configuration that resulted in an increase in the rotor power loading efficiency by more than 7% and reduced noise by more than 3 dBA when compared with a conventional rotor with all blades located in the same rotational plane

A Triassic crown squamate

Whiteside, David I., Chambi-Trowell, Sofía A. V., Benton, Michael J. (2022): A Triassic crown squamate. Science Advances 8 (48): 1-18, DOI: 10.1126/sciadv.abq827