Linear Rheological Response of a Series of Densely Branched Brush Polymers

We have examined the linear rheological responses of a series of welldefined, dense, regularly branched brush polymers. These narrow molecular weight distribution brush polymers had polynorobornene backbones with degrees of polymerization (DP) of 200, 400, and 800 and polylactide side chains with molecular weight of 1.4 kDa, 4.4 kDa, and 8.7 kDa. The master curves for these brush polymers were obtained by time temperature superposition (TTS) of the dynamic moduli over the range from the glassy region to the terminal flow region. Similar to other long chain branched polymers, these densely branched brush polymers show a sequence of relaxation. Subsequent to the glassy relaxation, two different relaxation processes can be observed for samples with the high molecular weight (4.4 and 8.7 kDa) side chains, corresponding to the relaxation of the side chains and the brush polymer backbone. Influenced by the large volume fraction of high molecular weight side chains, these brush polymers are unentangled. The lowest plateau observed in the dynamic response is not the rubbery entanglement plateau but is instead associated with the steady state recoverable compliance. Side chain properties affect the rheological responses of these densely branched brush polymers and determine their glassy behaviors

Land vehicle antennas for satellite mobile communications

The RF performance, size, pointing system, and cost were investigated concepts are: for a mechanically steered 1 x 4 tilted microstrip array, a mechanically steered fixed-beam conformal array, and an electronically steered conformal phased array. Emphasis is on the RF performance of the tilted 1 x 4 antenna array and methods for pointing the various antennas studied to a geosynchronous satellite. An updated version of satellite isolations in a two-satellite system is presented. Cost estimates for the antennas in quantities of 10,000 and 100,000 unites are summarized

Density scaling in viscous liquids: From relaxation times to four-point susceptibilities

We present numerical calculations of a four-point dynamic susceptibility, chi_4(t), for the Kob-Andersen Lennard-Jones mixture as a function of temperature T and density rho. Over a relevant range of T and rho, the full t-dependence of chi_4(t) and thus the maximum in chi_4(t), which is proportional to the dynamic correlation volume, are invariant for state points for which the scaling variable rho^gamma/T is constant. The value of the material constant gamma is the same as that which superposes the relaxation time, tau, of the system versus rho^gamma/T. Thus, the dynamic correlation volume is directly related to tau for any thermodynamic condition in the regime where density scaling holds. Finally, we examine the conditions under which the density scaling properties are related to the existence of strong correlations between pressure and energy fluctuations.Comment: 5 pages, 4 figures, updated reference

The Technologizing of inhumane practices

Australia's aggressive foreign policy stance, particularly on the refugee / illegal immigrant issue has been politically successful. This paper attributes this success to a two-part strategy. The first, using the theories of Said and Barthes, is to create a "ubiquitous semiotic" that plugs into Australia’s invasion myth. Founded on fear and ignorance it demonizes a recognisable "other", the "oriental" refugee demonised as a queue jumper. The second part of the strategy responds to the daily news and public affairs programs, which scrutinize government actions, but also provide the locus of contesting political discourses. The paper deals cursorily with the first part, the ubiquitous semiotic. The tactic of technologizing the inhumane is examined using sociolinguistic analysis of a television interview involving the Australian Immigration Minister. From this, it becomes evident how the process of classification into "other" allow the logic of technocratic processes to treat people inhumanely

On the dependence of the avalanche angle on the granular layer thickness

A layer of sand of thickness h flows down a rough surface if the inclination is larger than some threshold value theta which decreases with h. A tentative microscopic model for the dependence of theta with h is proposed for rigid frictional grains, based on the following hypothesis: (i) a horizontal layer of sand has some coordination z larger than a critical value z_c where mechanical stability is lost (ii) as the tilt angle is increased, the configurations visited present a growing proportion $_s of sliding contacts. Instability with respect to flow occurs when z-z_s=z_c. This criterion leads to a prediction for theta(h) in good agreement with empirical observations.Comment: 6 pages, 2 figure

Kovacs effects in an aging molecular liquid

We study by means of molecular dynamics simulations the aging behavior of a molecular model of ortho-terphenyl. We find evidence of a a non-monotonic evolution of the volume during an isothermal-isobaric equilibration process, a phenomenon known in polymeric systems as Kovacs effect. We characterize this phenomenology in terms of landscape properties, providing evidence that, far from equilibrium, the system explores region of the potential energy landscape distinct from the one explored in thermal equilibrium. We discuss the relevance of our findings for the present understanding of the thermodynamics of the glass state.Comment: RevTeX 4, 4 pages, 5 eps figure

Access to general health care services by a New Zealand population with serious mental illness.

INTRODUCTION: Literature suggests that good quality health care access can have a positive impact on the health of people with serious mental illness (SMI), but literature relating to patterns of access by this group is equivocal. AIM: This study was designed to explore health care access patterns in a group of people with SMI and to compare them with a general New Zealand population group, in order for health providers to understand how they might contribute to positive health outcomes for this group. METHODS: The study surveyed 404 mental health consumers aged 18-65 years receiving care from one district health board in Auckland about their patterns of health care access. Results were compared with those from the New Zealand Health Survey of the general population. RESULTS: Findings suggest that the SMI consumer respondents had poorer physical health than the general population respondents, accessed health care services in more complex ways and were more particular about who they accessed for their care than the general population respondents. There was some concern from SMI consumers around discrimination from health care providers. The study also suggested that some proactive management with SMI consumers for conditions such as metabolic syndrome was occurring within the health care community. DISCUSSION: The first point of access for SMI consumers with general health problems is not always the family general practitioner and so other health professionals may sometimes need to consider the mental and physical health of such consumers in a wider context than their own specialism

Prevalence of Anderson-Fabry disease in male patients with late onset hypertrophic cardiomyopathy

Background-Although studies have suggested that "late-onset" hypertrophic cardiomyopathy (HCM) may be caused by sarcomeric protein gene mutations, the cause of HCM in the majority of patients is unknown. This study determined the prevalence of a potentially treatable cause of hypertrophy, Anderson-Fabry disease, in a HCM referral population.Methods and Results-Plasma alpha-galactosidase A (alpha-Gal) was measured in 79 men with HCM who were diagnosed at greater than or equal to40 years of age (52.9 +/- 7.7 years; range, 40-71 years) and in 74 men who were diagnosed at <40 years (25.9 +/- 9.2 years; range, 8-39 years). Five patients (6.3%) with late-onset disease and 1 patient (1.4%) diagnosed at <40 years had low alpha-Gal activity. Of these 6 patients, 3 had angina, 4 were in New York Heart Association class 2, 5 had palpitations, and 2 had a history of syncope. Hypertrophy was concentric in 5 patients and asymmetric in 1 patient. One patient had left ventricular outflow tract obstruction. All patients with low alpha-Gal activity had alpha-Gal gene mutations.Conclusion-Anderson-Fabry disease should be considered in all cases of unexplained hypertrophy. Its recognition is important given the advent of specific replacement enzyme therapy