374 research outputs found
The Interlayer Formed Between Iron and an Acrylic Latex.
The anti-corrosive nature of steels coated with a commercially available acidic water-borne latex primer has been demonstrated to be considerably enhanced by the formation of an interfacial film between the coating and metal substrate. Novel sample preparation has enabled microtomed cross-sections of latex polymer coated metals to be analysed by TEM to establish the morphology and structure of the interlayer. Combined EDX and electron diffraction presents evidence for a chlorine containing mixed valence iron oxide/hydroxide - a pyroaurite-type compound, green rust I - existing in this region and attributes this formation to the observed enhanced anti-corrosive properties. Modifications to the latex polymer by soluble ionic pigment additions was performed to attempt to enhance the anti-corrosive nature of the coating by formation of different pyroaurite-type compounds based on the formula Mg6Fe2(OH)16CO3.4H2O, where Mg may be substituted by a suitable divalent cation and likewise Fe substituted by a suitable trivalent cation. Analysis of these modified coatings by TEM, XPS and A.C. impedance spectroscopy has elucidated their anti-corrosive action and identified the presence of polymer/metal and polymer/air films formed by ionic additions. In particular, the ionic addition of Mg(II) is found to considerably increase corrosion resistance in these latex coatings immersed in 3% NaCl. Models are presented for green rust formation and corrosion protection enhancement by soluble ionic additions
Queering the grammar school boy: class, sexuality and authenticity in the works of Colin MacInnes and Ray Gosling
In 1959 Colin MacInnes published the fourth in his series of social issue novels, Absolute Beginners. In it the unnamed protagonist is constructed as the iconic teenager, slick, cool, creative, with his ex-lover CrĂ©pe Suzette as the object of his art and as his Achilles heel. The novel is framed over one summer, against a backdrop of racial tension, which ultimately led the Boy towards adulthood. MacInnesâs protagonist has been dismissed as an emblem rather than a character, and MacInnes himself derided by George Melly as a perpetual teenager. However in this chapter, we will suggest that taken as a whole MacInnesâ work constructs a complex understanding of The Boyâs political possibilities intersecting with sexuality, gender, race and class. By integrating his novelistic work with his journalistic and activist writing, we will demonstrate the complexity of MacInnesâ Boy as an autonomous, queer political agent, embodied in the ultimate Boy; Ray Gosling. Goslingâs own writing becomes a lens through which to root historical understanding of teenagers and teenage cultures as sexual and racial constructs
Millisecond accuracy video display using OpenGL under Linux
To measure peopleâs reaction times to the nearest millisecond, it is necessary to know exactly when
a stimulus is displayed. This article describes how to display stimuli with millisecond accuracy on a
normal CRT monitor, using a PC running Linux. A simple C program is presented to illustrate how this
may be done within X Windows using the OpenGL rendering system. A test of this system is reported
that demonstrates that stimuli may be consistently displayed with millisecond accuracy. An algorithm
is presented that allows the exact time of stimulus presentation to be deduced, even if there are relatively
large errors in measuring the display time
A PC parallel port button box provides millisecond response time accuracy under Linux
For psychologists, it is sometimes necessary to measure people's reaction times to the nearest millisecond. This article describes how to use the PC parallel port to receive signals from a button box to achieve millisecond response time accuracy. The workings of the parallel port, the corresponding port addresses, and a simple Linux program for controlling the port are described. A test of the speed and reliability of button box signal detection is reported. If the reader is moderately familiar with Linux, this article should provide sufficient instruction for him or her to build and test his or her own parallel port button box. This article also describes how the parallel port could be used to control an external apparatus
Helically corrugated waveguide microwave pulse compression experiments
A high microwave pulse compressor based on a large diameter 5-fold helical waveguide structure was studied. The eigenwave dispersion was calculated using numerical and analytical techniques and compared with experimental measurements. The results of 5-fold helically corrugated waveguide microwave pulse compression experiments will be presented
Managing lifestyle change to reduce coronary risk: a synthesis of qualitative research on peoplesâ experiences
Background
Coronary heart disease is an incurable condition. The only approach known to slow its progression is healthy lifestyle change and concordance with cardio-protective medicines. Few people fully succeed in these daily activities so potential health improvements are not fully realised. Little is known about peoplesâ experiences of managing lifestyle change. The aim of this study was to synthesise qualitative research to explain how participants make lifestyle change after a cardiac event and explore this within the wider illness experience.
Methods
A qualitative synthesis was conducted drawing upon the principles of meta-ethnography. Qualitative studies were identified through a systematic search of 7 databases using explicit criteria. Key concepts were identified and translated across studies. Findings were discussed and diagrammed during a series of audiotaped meetings.
Results
The final synthesis is grounded in findings from 27 studies, with over 500 participants (56% male) across 8 countries. All participants experienced a change in their self-identity from what was âfamiliarâ to âunfamiliarâ. The transition process involved âfinding new limits and a life worth livingââ, âfinding support for selfâ and âfinding a new normalâ. Analyses of these concepts led to the generation of a third order construct, namely an ongoing process of âreassessing past, present and future livesâ as participants considered their changed identity. Participants experienced a strong urge to get back to ânormalâ. Support from family and friends could enable or constrain life change and lifestyle changes. Lifestyle change was but one small part of a wider âlifeâ change that occurred.
Conclusions
The final synthesis presents an interpretation, not evident in the primary studies, of a person-centred model to explain how lifestyle change is situated within âwiderâ life changes. The magnitude of individual responses to a changed health status varied. Participants experienced distress as their notion of self identity shifted and emotions that reflected the various stages of the grief process were evident in participantsâ accounts. The process of self-managing lifestyle took place through experiential learning; the level of engagement with lifestyle change reflected an individualâs unique view of the balance needed to manage ârealistic changeâ whilst leading to a life that was perceived as âworth livingâ. Findings highlight the importance of providing person centred care that aligns with both psychological and physical dimensions of recovery which are inextricably linked
Biology ideology and pastiche hegemony
As knowledge about the biological foundation of the modern patriarchal gender order is increasingly challenged within late-modern social worlds enclaves persist in which men and women can attempt to recreate understandings of the "natural" basis of sex difference. Within "Power Gym," male boxers were able to symbolize their bodies and behaviors in such a manner. The language and logic of popular scientific discourses authored and authorized notions of an "innate" manhood. The ability to instrumentally deploy one's manliness in symbolically legitimate ways could then be represented and emotionally experienced as a man's biological right and obligation. Through scripted performances of "mimetic" violence and self-bullying, the boxers were able to experience this discursive naturalness and carve out a masculinity-validating social enclave. As such, they accessed a "patriarchal dividend" by securing a local pastiche hegemony in which discourses surrounding men's natural place as physically and psychologically dominant remained largely uncontested. Through the reflexive appropriation of "science," within appropriate subcultural codes, these men could negotiate taboos and restrictions that are characteristic of late-modern social worlds. When considered in this way, the power of "scientific" truth claims to explain and justify a certain level of violence, aggression, and behaviors coded as masculine, comes to the fore
Can we predict real-time fMRI neurofeedback learning success from pretraining brain activity?
Neurofeedback training has been shown to influence behavior in healthy participants as well as to alleviate clinical symptoms in neurological, psychosomatic, and psychiatric patient populations. However, many real-time fMRI neurofeedback studies report large inter-individual differences in learning success. The factors that cause this vast variability between participants remain unknown and their identification could enhance treatment success. Thus, here we employed a meta-analytic approach including data from 24 different neurofeedback studies with a total of 401 participants, including 140 patients, to determine whether levels of activity in target brain regions during pretraining functional localizer or no-feedback runs (i.e., self-regulation in the absence of neurofeedback) could predict neurofeedback learning success. We observed a slightly positive correlation between pretraining activity levels during a functional localizer run and neurofeedback learning success, but we were not able to identify common brain-based success predictors across our diverse cohort of studies. Therefore, advances need to be made in finding robust models and measures of general neurofeedback learning, and in increasing the current study database to allow for investigating further factors that might influence neurofeedback learning
Periodic GW level microwave pulses in X-band from a combination of a relativistic backward wave oscillator and a helical waveguide compressor
Backward Wave Oscillators (BWO's) utilizing moderately relativistic (550kV), high-current (10 kA) electron beams are capable of producing hundreds of MWs of pulsed radiation in the centimeter wavelength range. Such relativistic BWOs (RBWOs) allow for broadband, smooth, frequency-tuning via adjustment of the accelerating potential; making them an attractive source for use in frequency-swept pulse compression. This paper presents results of a 2.86m long 5-fold helically corrugated, dispersive pulse compressor where a maximum power compression ratio of 25 was achieved by compressing an input microwave pulse of 80 ns duration swept from 9.65 GHz to 9.05 GHz into a 1.6ns Gaussian-envelope pulse. For an average input power of 5.8 kW generated by a conventional traveling wave tube amplifier, a peak pulse output power of 145 kW was measured corresponding to an energy efficiency of 66%. An X-band relativistic BWO, designed to drive a 0.97m long 5-fold compressor, was built and tested using the accelerating potential generated by a SINUS-6 highcurrent accelerator. The experimental RBWO operated close to the predicted power of 700MW with its oscillation frequency varied from 10 to 9.6GHz via the falling edge of the voltage pulse. It was demonstrated that the 15ns duration frequency-swept part of the RBWO pulse was effectively compressed resulting in a 4.5-fold peak power increase with a maximum power of 3.2 GW generated. The potential for a 5-fold helical waveguide to compress longer duration pulses generated by a RBWO is discussed
Complex type 4 structure changing dynamics of digital agents: Nash equilibria of a game with arms race in innovations
The new digital economy has renewed interest in how digital agents can innovate. This follows the legacy of John von Neumann dynamical systems theory on complex biological systems as computation. The Gödel-Turing-Post (GTP) logic is shown to be necessary to generate innovation based structure changing Type 4 dynamics of the Wolfram-Chomsky schema. Two syntactic procedures of GTP logic permit digital agents to exit from listable sets of digital technologies to produce novelty and surprises. The first is meta-analyses or offline simulations. The second is a fixed point with a two place encoding of negation or opposition, referred to as the Gödel sentence. It is postulated that in phenomena ranging from the genome to human proteanism, the Gödel sentence is a ubiquitous syntactic construction without which escape from hostile agents qua the Liar is impossible and digital agents become entrained within fixed repertoires. The only recursive best response function of a 2-person adversarial game that can implement strategic innovation in lock-step formation of an arms race is the productive function of the Emil Post [58] set theoretic proof of the Gödel incompleteness result. This overturns the view of game theorists that surprise and innovation cannot be a Nash equilibrium of a game
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