Fluid machines: Expanding the limits, past and future

During the 40 yr period from 1940 to 1980, the capabilities and operating limits of fluid machines were greatly extended. This was due to a research program, carried out to meet the needs of aerospace programs. Some of the events are reviewed. Overall advancements of all machinery components are discussed followed by a detailed examination of technology advancements in axial compressors and pumps. Future technology needs are suggested

Some observations of the effects of radial distortions on performance of a transonic rotating blade row

A single rotating blade row was tested with two magnitudes of tip radial distortion and two magnitudes of hub radial distortion imposed on the inlet flow. The rotor was about 50 centimeters (20 in.) in diameter and had a design operating tip speed of approximately 420 meters per second (1380 ft/sec). Overall performance at 60, 80, and 100 percent of equivalent design speed generally showed a decrease (compared to undistorted flow) in rotor stall margin with tip radial distortion but no change, or a slight increase, in rotor stall margin with hub radial distortion. At design speed there was a decrease in rotor overall total pressure ratio and choke flow with all inlet flow distortions. Radial distributions of blade element parameters are presented for selected operating conditions at design speed

Anticoagulants for acute ischaemic stroke

Peer reviewedPublisher PD

The great outdoors: how a green exercise environment can benefit all

The studies of human and environment interactions usually consider the extremes of environment on individuals or how humans affect the environment. It is well known that physical activity improves both physiological and psychological well-being, but further evidence is required to ascertain how different environments influence and shape health. This review considers the declining levels of physical activity, particularly in the Western world, and how the environment may help motivate and facilitate physical activity. It also addresses the additional physiological and mental health benefits that appear to occur when exercise is performed in an outdoor environment. However, people's connectedness to nature appears to be changing and this has important implications as to how humans are now interacting with nature. Barriers exist, and it is important that these are considered when discussing how to make exercise in the outdoors accessible and beneficial for all. The synergistic combination of exercise and exposure to nature and thus the 'great outdoors' could be used as a powerful tool to help fight the growing incidence of both physical inactivity and non-communicable disease. © 2013 Gladwell et al.; licensee BioMed Central Ltd

O medo do Outro. Planeamento através de diálogos terapêuticos em comunidades altamente conflituais

The concept of difference is becoming more and more central to the way in which urban societies are understood, and a whole raft of theorizing (feminist, postcolonial, poststructuralist, queer, and psychoanalytic theories, for example) has contributed to this new awareness. But so too has a new politics of difference which has been re-shaping not only how we think about cities and urban processes but, more importantly, re-shaping cities themselves. Managing these differences has become an increasing challenge to the running of cities and has particular implications for the city-building professions. The choice is clear: ghettoization or hybridization; separate lives, or change-by-conjoining. The challenge is clear. How to build new hybrid communities rather than increasingly segmented and fragmented cities? Planning’s responses to this crucial question has not often been really satisfactory. Many scholars have acknowledged the overall failure of the planning system to respond to the increasing cultural diversity of the city, to the ways in which the values and norms of the dominant culture are reflected in plans, planning codes and bylaws, legislation, heritage and urban design practices, to planners’ inability to analyze issues from a multicultural perspective or to design participatory processes that bring racial and ethnic groups into the planning process (Ameyaw, 2000, p. 105). Finding out ways to manage our coexistence in increasingly diverse urban landscapes is not an easy task. A different path can be built: a path based on a communicative and collaborative planning approach whose goal is to encourage a dialogue among conflicting subjectivities. We call it a therapeutic approach (Sandercock 2003; Sandercock and Attili 2014): a way to engage with emotions in planning practice, recognising the importance of working with and through people’s hopes, fears, memories, wounds. In this respect many scholars, in the recent years, have been drawing attention to the need of creating a dialogic space for the unspeakable, for emotions to be heard and named, for talk of fear and loathing as well as of hope and transformation (Marris 1974; Baum 1997, Forester 1999, 2009; Sandercock 2003; Erfan 2013). This urgency involves the design of a safe space in which conflicting parties can meet and speak without fear of being dismissed, attacked, or humiliated—a new space of recognition in which differences and historic injustices are acknowledged, as a necessary prelude to addressing contemporary conflict

Secondary flow spanwise deviation model for the stators of NASA middle compressor stages

A model of the spanwise variation of deviation for stator blades is presented. Deviation is defined as the difference between the passage mean flow angle and the metal angle at the outlet of a blade element of an axial compressor stage. The variation of deviation is taken as the difference above or below that predicted by blade element, (i.e., two-dimensional) theory at any spanwise location. The variation of deviation is dependent upon the blade camber, solidity and inlet boundary layer thickness at the hub or tip end-wall, and the blade channel aspect ratio. If these parameters are known or can be calculated, the model provides a reasonable approximation of the spanwise variation of deviation for most compressor middle stage stators operating at subsonic inlet Mach numbers

Gesture as a predictor of language development in infants at high risk for autism spectrum disorders

In typically developing children, gesture use predates and predicts changes in language. Because language development is often delayed in later-born siblings of children with autism spectrum disorders (ASD) (who are at heightened biological risk for the disorder; heightened risk infants: HR), even those who are not eventually diagnosed with ASD, gesture may be one of the earliest indicators of later delays. To examine the pattern of gesture use and language development in HR infants, gesture referents for HR infants and low risk (LR) comparison infants were coded at 14 and 18 month home visits. HR infants who went on to receive either a language delay (LD) or ASD diagnosis exhibited less frequent gesture use and used gesture to indicate a smaller variety of referents than their typically developing peers at both 14 and 18 months. In comparison to LR infants, HR infants who went on to receive LD or ASD diagnoses also exhibited smaller increases in gesture use from 14 to 18 months. While there was a significant positive correlation between gesture frequency at 14 months and vocabulary size at 18 months for the HR group, HR infants that received eventual LD or ASD diagnoses converted a smaller proportion of gesture referents to words in later vocabulary than did LR infants. Taken together, these results suggest that early gesture use and its relationship to later language development differentiates HR infants who receive later LD or ASD diagnoses from typically developing infants, indicating that gesture may have the potential to be used as marker of language delays prior to the onset of speech

Data summary and computer program for axial-flow pump rotor performance

Assembly of noncavitating blade element performance data for axial-flow pump rotor configurations has been collected and organized. Program facilitates handling large amounts of experimental data involved and may be used as data reduction program to process flow and performance measurements from other axial-flow pump configurations

Off-design correlation for losses due to part-span dampers on transonic rotors

Experimental data from 10 transonic fan rotors were used to correlate losses created by part-span dampers located near the midchord position on the rotor blades. The design tip speed of these rotors varied from 419 to 425 m/sec, and the design pressure ratio varied from 1.6 to 2.0. Additional loss caused by the dampers for operating conditions between 50 and 100 percent of design speed were correlated with relevant aerodynamic and geometric parameters. The resulting correlation predicts the variation of total-pressure-loss coefficient in the damper region to a good approximation