Exact solutions for some simple flows of an Oldroyd-B fluid

Summary We present two simple but elegant solutions for the flow of an Oldroyd-B fluid. First, we consider the flow past an infinite porous plate and find that the problem admits an asymptotically decaying solution in the case of suction at the plate, and that in the case of blowing it admits no such solution. Second, we study the longitudinal and torsional oscillations of an infinitely long rod of finite radius. The solutions are found in terms of Bessel functions.     

Influence of rapid thermal annealing effect on electrical and structural properties of Pd/Ru Schottky contacts to n-type GaN

Pd/Ru metallization scheme is fabricated on n-GaN as a Schottky contact, and the electrical and structural properties have been investigated as a function of annealing temperature by current–voltage (I–V), capacitance–voltage (C–V), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) measurements. As-deposited Ru/Pd/n-GaN contact yielded Schottky barrier height (SBH) of 0.67 eV (I–V) and 0.79 eV (C–V), respectively. Further, it is observed that the Schottky barrier height increases to 0.80 eV (I–V) and 0.96 eV (C–V) for the contact annealed at 300 °C. However, both I–V and C–V measurements indicate that the barrier height slightly decreased when the contacts are annealed at 400 °C and 500 °C. From the above observations, the optimum annealing temperature for Pd/Ru Schottky contact is 300 °C. Norde method is also employed to extract the barrier height of Pd/Ru Schottky contacts which are in good agreement with those obtained by the I–V technique. X-ray photoelectron spectroscopy results shows that the Ga 2p core-level shift towards the low-energy side for the contact annealed at 300 °C compared to the as-deposited contact. Based on the XPS and XRD results, the reason for the increase in SBH upon annealing at 300 °C could be attributed to the formation of gallide phases at the Ru/Pd/n-GaN interface vicinity. The AFM results showed that the overall surface morphology of the Pd/Ru Schottky contacts on n-GaN is fairly smooth. The above observations reveal that the Pd/Ru Schottky contact is attractive for high-temperature device applications.     

Tetralogy of Fallot with flap valve ventricular septal defect producing suprasystemic right ventricular pressure: echocardiographic observations

The study objectives were to gain insight into how the terms "dieting" and "binge eating" are understood and used by adolescents and to assess whether interpretations of these terms are consistent across age and gender. Twenty-five focus groups were conducted with 203 adolescents (138 girls and 65 boys) in urban public junior and senior high schools. Respondents were asked questions about dieting and binge eating behaviors. In the majority of groups (n=19), healthful eating behaviors, such as eating less fat or more fruits and vegetables, were mentioned in reference to dieting. However, in many of the groups (n=13) unhealthful eating behaviors, such as skipping meals or "starvation," were also described. Dieting was frequently described as an umbrella term for different behaviors aimed at weight control (ie, physical activity) or in nonbehavioral terms (ie, as a desire or plan for weight loss). Although binge eating was described as overeating by many participants, often it was not clear if youth were referring to uncontrolled overeating. In nearly half of the groups, participants indicated unfamiliarity with the term "binge eating." There was some confusion between binge eating and other forms of disordered eating. The findings suggest that prevalence rates of self-reported dieting and binge eating behaviors should be interpreted with caution and it should not be assumed that the majority of adolescents who self-report dieting are engaging in unhealthful behaviors. In providing nutrition counseling to youth, and in assessing dieting and binge eating behaviors in clinical settings and in research studies, specific behaviors should be defined.     

Palliative home care--the Calicut experience

A three-year-old palliative care unit in Calicut, in the south Indian state of Kerala, started a home care service in June 1996. This paper reviews the first year of operation of the service; in this period 340 home visits were made. The service aims to deliver palliative care to the patients who are unable to reach the hospital, to empower patients to care for themselves and to empower the family to care for patients. One doctor and a few trained volunteers form the team. In addition to control of physical symptoms and emotional support, the home visits permitted minor procedures including nasogastric intubation, catheterization of bladder, dressing of wounds and intravenous fluid therapy. In some cases, the visits helped to change the attitude of families towards the patients--for example, allaying fear of contagion. In some instances, the visits changed the attitude of the neighbourhood towards the patient for the better. In spite of problems like the distances involved and bad roads, the experience of this team shows that a home care system is possible and essential for delivery of palliative care in India.     

Ultraviolet-B effects on Spirulina platensis cells: modification of chromophore-protein interaction and energy transfer characteristics of phycobilisomes

Neuronal-growth-inhibitory factor (GIF) is a metalloprotein specific to the central nervous system which has been linked to Alzheimer's disease. The high metal content, approximately seven metal atoms/protein molecule, and 70% sequence identity to mammalian metallothioneins (MT), including a preserved array of 20 cysteinyl residues, place GIF in the family of MT. In contrast to MT, native GIF isolated from human or bovine brain contains an unusual metal composition, viz. four Cu(I) and three Zn(II) per polypeptide chain. Cu and/or Zn K-edge X-ray absorption spectra have been recorded for native Cu, Zn-GIF, Zn-substituted GIF, and these metals bound to the 32-residue N-terminal domain, Cu4-, Cu6- or Zn3-GIF-(1-32) at 77 K. The results are consistent with the metals being bound to the protein by cysteinyl residues in every case. The Cu-S distance is approximately 2.25 A and the EXAFS is considered to be consistent with primarily trigonal coordination of the Cu(I); Cu...Cu backscattering is observed at approximately 2.67 A, indicative of the formation of Cu(x)(Scys)y clusters. Thus, the Cu(I) environment is similar to that observed in MT. This is also the case for Zn(II), with 4 S at approximately 2.34 A. However, in contrast to Zn-MT for Zn-substituted GIF and Zn3-GIF-(1-32), Zn...Zn backscattering is observed at approximately 3.28 A. The significance of these results are discussed with respect to the specific biological activity of GIF.     

A model for the thermo-oxidative degradation of polyimides

Polyimides, due to their superior mechanical behavior at high temperatures, are used in a variety of applications that include aerospace, automobile and electronic packaging industries, as matrices for composites, as adhesives etc. In this paper, we extend our previous model in S. Karra and K. Rajagopal (Mech. Mater. 43(1):54?C61, 2011), to include thermo-oxidative degradation of these high temperature polyimides. Appropriate forms for the Helmholtz potential and the rate of dissipation are chosen to describe the degradation. The results for a specific boundary value problem, using our model, compares well with the experimental creep data for PMR-15 resin that is aged in air.     

Walking the tightrope between feeling good and being accurate: Mood as a resource in processing persuasive messages.

Three studies investigated the influence of mood states on the processing of positive and negative information regarding caffeine consumption and on the impact of this information on one's mood, attitudes, and intentions. The results were consistent with the predictions of the mood-as-a-resource hypothesis: First, the induction of positive mood in high (compared with low) caffeine consumers enhanced recall of negative information about caffeine consumption. Second, processing information about caffeine consumption undermined the positive mood of high (but not low) caffeine consumers. Third, the induction of positive mood enhanced the impact of negative information about caffeine on high (compared with low) caffeine consumers' attitudes and intentions toward caffeine consumption. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A novel wideband fractal-shaped MIMO antenna for brain and skin implantable biomedical applications

A novel fractal-shaped wideband multiple-input multiple-output (MIMO) antenna is proposed for brain and skin implantable applications. This antenna works in the 2.4–2.48 GHz band of industrial, scientific, and medical (ISM) standards. The fractal-shaped wideband MIMO antenna is miniature in size with a footprint of $0.13\mathrm{\lambda }\times 0.06\mathrm{\lambda }\times 0.01\mathrm{\lambda }$. Rogers RT/Duroid 6010 high-dielectric substrate material is used to fabricate the optimized design in order to validate the implantable MIMO antenna structure. The same high-permittivity substrate material has been used as a superstrate. Experiments were carried out in brain and skin-mimicking gel at 2.45 GHz in the ISM band. The proposed antenna has a peak gain of −21.3 dBi at 2.45 GHz. High isolation (>20 dB) between two MIMO ports is attained. The proposed antenna achieves a fractional bandwidth of 36.76% and an impedance bandwidth of 1.02 GHz. According to IEEE safety regulations for 1- and 10-g tissues, the computed maximum specific absorption rate (SAR) is safe bound.