Hardware schemes for fast Fourier transform, part 7.4A

Real-time fast fourier transformer (FFT) processing of a MST radar data and cost-effective approaches to hardware FFT generation were studied. Previously devised hardware FFT configurations are described including the estimated number of chips used and the time required to perform a 1024-point FFT. The remaining entries in the table correspond to original designs, which presuppose the availability of a microcomputer and a modestly complicated hardware peripheral. These original designs, all of which implement a radix-4 FFT with twiddle factors, are assigned model numbers to make them easier to refer to

Reduction of JT8D powered aircraft noise by engine refanning

The technical feasibility is described of substantially reducing the noise levels of existing JT8D powered aircraft by retrofitting the existing fleet with quieter refan engines and new acoustically treated nacelles. No major technical problems exist that preclude the development and installation of refanned engines on aircraft currently powered by the JT8D engine. The refan concept is technically feasible and provides calculated noise reductions of from 7 to 8 EPNdb for the B727-200 aircraft and from 10 to 12 EPNdb for the DC-9-32 aircraft at the FAR Part 36 measuring stations. These noise levels are lower than both the FAR Part 36 noise standards and the noise levels of the wide-body DC-10-10. Corresponding reductions in the 90 EPNdb footprint area are estimated to vary from about 70 percent for the DC-9 to about 80 percent for the B727

Archaeological building investigation and evaluation : City Tower, Todd Street, Manchester

In July 2016, Salford Archaeology was commissioned by Unique Boutique Hotels (Manchester) Ltd to undertake an historic building investigation of the former Cathedral School on Todd Street, Manchester (centred on SJ 8406 9886). Following the demolition of the building in November 2016, Bowmer & Kirkland Ltd commissioned Salford Archaeology to carry out an archaeological evaluation on the land. Both elements of the project were required as part of a redevelopment scheme. The historic building investigation was commensurate with a Level I-type survey, and the evaluation comprised the excavation of a single trench, which aimed to establish the presence or absence of buried archaeological remains within the proposed development area. An archaeological desk-based assessment compiled in 2010 demonstrated that the study area had the potential for the survival of remains relating to 18th- and 19th-century buildings, including housing, public houses and a series of schools. The site’s proximity to the original medieval core of Manchester also raised the possibility for earlier medieval remains being present in uncellared areas of the site, particularly within a former central courtyard. The historic building investigation concluded that the remnants of the former Cathedral School had been subject to considerable remodelling and alterations during the later 19th and 20th centuries, particularly in the basement and ground floor, with a resultant loss of historic fabric. The investigation has enabled an appropriate record of the building to be completed prior to its demolition. The evaluation trench excavated across the study area revealed that basements had removed all remains at the south-east and north-west ends of the trench. Natural gravels were observed between these basements, but did not contain any features of archaeological significance. The natural gravels were tested by excavating a sondage to 4.2m, and were shown to be consistent throughout, becoming much more indurated at depth. The results obtained from the evaluation trenches have indicated that no remains of archaeological significance survive within the study area, and that no further archaeological work in advance of development is merited

Role of the host cell in bacteriophage T4 development. II. Characterization of host mutants that have pleiotropic effects on T4 growth

Mutant host-defective Escherichi coli that fail to propagate bacteriophage T4 and have a pleiotropic effect on T4 development have been isolated and characterized. In phage-infected mutant cells, specific early phage proteins are absent or reduced in amount, phage DNA synthesis is depressed by about 50%, specific structural phage proteins, including some tail and collar components, are deficient or missing, and host-cell lysis is delayed and slow. Almost all phage that can overcome the host block carry mutantions that map in functionally undefined 'nonessential' regions of the T4 genome, most near gene 39. The mutant host strains are temperature sensitive for growth and show simultaneous reversion of the ts phenotype and the inability to propagate T4+. The host mutations are cotransduced with ilv (83 min) and may lie in the gene for transcription termination factor rho

Component test program for variable-cycle engines

Variable cycle engine (VCE) concepts for a supersonic cruise aircraft were studied. These VCE concepts incorporate unique critical components and flow path arrangements that provide good performance at both supersonic and subsonic cruise and appear to be economically and environmentally viable. Certain technologies were identified as critical to the successful development of these engine concepts and require considerable development and testing. The feasibility and readiness of the most critical VCE technologies, was assessed, a VCE component test program was initiated. The variable stream control engine (VSCE) component test program, tested and evaluated an efficient low emission duct burner and a quiet coannular ejector nozzle at the rear of a rematched F100 engine