Basic research in wake vortex alleviation using a variable twist wing

The variable twist wing concept was used to investigate the relative effects of lift and turbulence distribution on the rolled up vortex wake. Several methods of reducing the vortex strength behind an aircraft were identified. These involve the redistribution of lift spanwise on the wing and drag distribution along the wing. Initial attempts to use the variable twist wing velocity data to validate the WAKE computer code have shown a strong correlation, although the vorticity levels were not exactly matched

Detailed pressure distribution measurements obtained on several configurations of an aspect-ratio-7 variable twist wing

Detailed pressure distribution measurements were made for 11 twist configurations of a unique, multisegmented wing model having an aspect ratio of 7 and a taper ratio of 1. These configurations encompassed span loads ranging from that of an untwisted wing to simple flapped wings both with and without upper-surface spoilers attached. For each of the wing twist configurations, electronic scanning pressure transducers were used to obtain 580 surface pressure measurements over the wing in about 0.1 sec. Integrated pressure distribution measurements compared favorably with force-balance measurements of lift on the model when the model centerbody lift was included. Complete plots and tabulations of the pressure distribution data for each wing twist configuration are provided

Low-speed wind-tunnel investigation of wing fins as trailing-vortex-alleviation devices on a transport airplane model

The trailing-vortex-alleviation effectiveness of both a one- and a two-fin configuration (semicircular with a radius of 0.043 semispan) on a jumbo-jet transport airplane model in its landing configuration was investigated in the Langley V/STOL tunnel, by the trailing-wing sensor technique. The fins were located on the upper surface of the transport model wing along the 30-percent-chord line. The fin configurations were effective in reducing the vortex-induced rolling moment, by amounts varying from 28 to 60 percent, on the trailing wing model located at a distance of 7.8 transport model wing spans downstream of the transport model. The flow over the fins and over the transport airplane model wing downstream of the fins was observed to be separated and turbulent. All fin configurations caused a reduction in maximum lift coefficient, a positive increment in drag coefficient, and an increment in nose-up pitching-moment coefficient on the transport airplane model

Assets at risk:menstrual cycle variation in the envisioned formidability of a potential sexual assailant reveals a component of threat assessment

Abstract Situations of potential agonistic conflict demand rapid and effective deci-sion-making. The process of threat assessment includes assessments of relative fighting capacity, assessments of the likelihood of attack, and assessments of the extent to which one′s assets are at risk. The dimensions of physical size and strength appear to serve as key parameters in a cognitive representation summarizing multiple constituents of threat assessment. Here, we examine the thesis that this same representation summa-rizes asset risk. The fitness costs of sexual assault are in part a function of conception risk, as pregnancy due to assault compromises female choice and imperils existing and subsequent male investment. Prior research indicates that women′s attitudes and behaviors vary systematically across the menstrual cycle in a manner that would have reduced the likelihood of sexual assault during periods of greatest fertility in ancestral women. If the envisioned size and strength of a potential antagonist is used to represent asset risk, and if the threat that sexual assault poses to a woman′s reproductive assets is in part a product of her fertility, then the conceptualized size and strength of a potential sexual assailant should be a function of conception risk. We find support for thi

Preliminary results of simulated vortex encounters by a twin-engine, commercial aircraft during final landing approach

Piloted simulations of encounters with vortices of various ages and degrees of attenuation were performed with the Visual Motion Simulator. In the simulations, a twin engine, commercial transport on final approach, encountered the modeled vortices of a four engine, wide body, commercial transport. The data show the effect of vortex age and attenuation on the severity of the initial upset, as well as the effect of the vortex encounters on the landing capability

Design and development of a 5 kV isolated solid state switch

A unique microcircuit intended for use as a shorting switch for large extraterrestrial solar cell arrays is described. The packaging design for the 5 kV isolated hybrid switch is different from most hybrid microcircuits in that it utilizes a compartmentalized plastic case (a portion of which is encapsulated), is not hermetic, and is designed for high voltage operation

Opportunities and challenges of new product development and testing for longevity in clothing

Many types of clothing are now seen as disposable by consumers in the UK even though durability is among the top criteria that consumers claim to use when buying garments (WRAP, 2012). Routine tests for clothing performance carried out by retailers are generally designed to ensure garments are 'fit for purpose', not to establish durability or longevity. Designing clothing that lasts longer is, however, key to reducing waste and has become a government policy objective (Defra, 2011). This paper discusses the findings from a recent research project, carried out for WRAP (Waste and Resources Action Programme), that investigated the opportunities for measuring, specifying and communicating aspects of clothing longevity within a Longevity Protocol. The Protocol is intended to enable retailers to obtain a reliable indication of garment life expectancy and was piloted in conjunction with clothing industry practitioners. It incorporates recommendations for best practice in product development and a testing regime that provides an indication of garment life expectancy (WRAP, 2014). Overall, the findings from the pilot suggest that it is possible to test for garment longevity, however, this process can be drawn-out and may not fit easily into the normal product development process. Furthermore, variations in consumer wearing patterns and laundering make it difficult for retailers to guarantee and communicate product lifetimes in absolute terms. The research adds to a growing body of evidence that supports the concept of design for clothing longevity. The findings will help to inform strategies for the implementation of government policy on sustainable clothing, but point to the need for refined testing processes to support this agenda

Generation and Delivery of Charged Aerosols to Infant Airways

The administration of pharmaceutical aerosols to infants on mechanical ventilation needs to be improved by increasing the efficiency of delivery devices and creating better ways of evaluating potential therapies. Aerosolized medicines such as surfactants have been administered to ventilated infants with mixed results, but studies have shown improvement in respiratory function with a much lower dose than with liquid instillation through an endotracheal tube (ETT). An aerosolized medicine must be transported through the ventilation tubing and deposit in the lungs to have the desired therapeutic response. This work has taken a systematic approach to (i) develop new devices for the efficient production of small sized charged pharmaceutical aerosols, (ii) adapt a lead device to an infant ventilation system, (iii) develop a novel breathing infant lung (BIL) in vitro model capable of capturing lung delivery efficiency in an infant without the need for human subjects testing, and (iv) evaluate the hypothesis that small sized charged pharmaceutical aerosols can improve drug delivery efficiency to the lungs of a ventilated infant. Three new devices were developed and screened for the efficient generation of small sized charged pharmaceutical aerosols, which were: wick electrospray, condensational vapor, and a modified vibrating mesh nebulizer in a streamlined low flow induction charger (LF-IC). Of these devices, only the LF-IC produced a small [mean(SD) = 1.6(0.1) micrometers] and charged (1/100 Rayleigh limit) aerosol at a pharmaceutically relevant production rate [mean(SD) = 183(9) micrograms per minute]. The LF-IC was selected as a lead device and adapted for use in an infant ventilation system, which produced an increase in in vitro lung filter deposition efficiency from 1.3% with the commercial system to 34% under cyclic ventilation conditions. The BIL model was first shown to produce a realistic pressure-volume response curve when exposed to mechanical ventilation. The optimized LF-IC was then implemented in the BIL model to demonstrate superior reduction in inspiratory resistance when surfactant was delivered as an aerosol compared to liquid instillation. For the delivery of an aerosolized medication, the lung deposition efficiency increased from a mean(SD) 0.4(0.1)% when using the conventional delivery system to 21.3(2.4)% using the LF-IC in the BIL model, a 59-fold increase. The charged aerosol produced by the LF-IC was shown to have more depositional loss in the LF-IC than an uncharged aerosol, but the charge decreased the exhaled fraction of aerosol by 17%, which needs additional study to achieve statistical significance. Completion of this work has produced a device that can achieve lung delivery efficiency that is 59-fold greater than aerosols from conventional vibrating mesh nebulizers in invasively ventilated infants using a combination of small particle size, synchronization with inspiration and appropriate charge. The BIL model produced in this work can be used to test clinically relevant methods of administering medications to infants and can be used to provide more accurate delivery estimates for development of new nebulizers and inhalers. The LF-IC developed in this work could be used for controlled and efficient delivery of aerosolized antibiotics, steroids, non-steroidal anti-inflammatories, surfactants, and vasodilators

Growth Factor and Growth Factor Receptor Localization in the Hair Follicle Bulge and Associated Tissue in Human Fetus

The bulge region of the hair follicle has been thought to contain follicular stem cells. The bulge in the human follicle is a collection of undifferentiated cells that is prominent only in the fetal period. Antibodies that recognize epidermal growth factor (EGF), transforming growth factor-α (TGF-α), EGF receptor, platelet-derived growth factor (PDGF) A and B chains, PDGF α and β receptors, and the low-affinity nerve growth factor receptor (p75) were used to study the bulge and associated mesenchymal cells in this fetal period. Weak EGF and TGF-α immunoreactivities were seen in the bulge. Confocal laser scanning microscopic images revealed intracytoplasmic and intranuclear punctate patterns of immunoreactivities in the bulge cells labeled by anti-EGF and anti-TGF-α antibodies. All the bulge cells stained strongly for EGF receptor. Cells within the bulge were labeled both with PDGF A chain and with PDGF B chain, although the immunoreactivities were weak in the outermost layer of cells. The follicular sheath was strongly immunoreactive with antibodies against both PDGF α and β receptors. p75 was expressed in mesenchymal cells around the hair follicle and in the lower portion of the bulge. These differential labeling patterns suggested that EGF, TGF-α, and nerve growth factor may be involved in regulation of the growth and differentiation of bulge cells and that PDGFS may have related functions in the interaction arising between the bulge and associated tissue during follicle morphogenesis

Between furniture and infrastructure: expanding disciplinarity

The challenges presented to society by rapid urbanisation and climate change directly call for the broad synthetic spatial knowledge that lies in the province of architecture and urban design. Curiously, in the face of such challenges, the discipline of architecture seems to have entered a period of self-imposed myopia. In recent years, architecture has lost ground in many of those areas that once lay within the disciplinary realm. The societal value ascribed to the spatial imagination is diminishing, and with it the value of operating as a generalist. The familiar rise of international multidisciplinary firms illustrate a shift towards regarding planning and urban design as a problem-solving activity. The multidisciplinary model privileges the instrumental knowledge of engineering, and the managerial routines of traditional planning and project management. The model depends not on synthesising different sorts of knowledge from within the discipline, but rather the consensually mute operation of diverse specialists contributing to the demands of a particular project without overarching synthetic authorship. Furthermore, the closed system thinking of specialists maps very easily to the emergent tasks of late capitalist environments: the establishment of privatised and invisible infrastructures and controlled, risk-managed versions of the city, with many claims made upon it. If the model of multidisciplinary consultancy is a consequence of increasing corporate power, the weakening of the social contract matches the fragility of the concept of a vital civil society, the health of which would be indicated by participatory infrastructures and negotiative, agonic public space. From these observations the thesis argues for a generalist spatial design practice, supported by evidence of a particular and distinctive way of working. Holbrook's work from the last two decades provide illustration of how the architectural imagination can engage positively with highly complex situations, and establish a bridge between the scales of strategy, planning and infrastructure and the concrete experience of the resulting environment. Case studies are drawn primarily from the work of Holbrook's practice 5th Studio, working in East Anglia, England - one of the densest concentrations of overlaid infrastructure, historic and natural conservation anywhere. 5th Studio has always regarded its approach as prospective and propositional and the research has validated and formalised its spatially entrepreneurial mode of inventing projects. The thesis concludes with an interview with the critic Ellis Woodman and a transcribed discussion with Shelley MacNamara of Grafton Architects