Boundary Layer Effect on the Surface Pressure of an Infinite Cone in Supersonic Flow

The theory of Taylor and Maccoll (Ref,1) gives the surface pressure on an infinite cone in supersonic flow as a function of the cone vertex angle and the free stream Mach number and static pressure for a gas of vanishing viscosity. When a slender conical probe is used together with an impact pressure probe to determine the static pressure and Mach number in a low density gas stream, it is desirable to have some theoretical estimate of the effect of viscous boundary layer on the probe readings. Theoretical and experimental results with respect to impact probes have been presented in Refs. 5 and 6. A simple approximation for a conical probe based on linearized supersonic flow and compressible boundary layer theory is presented here

Analysis of Tyrosine Kinase Inhibitor-Mediated Decline in Contractile Force in Rat Engineered Heart Tissue

Introduction Left ventricular dysfunction is a frequent and potentially severe side effect of many tyrosine kinase inhibitors (TKI). The mode of toxicity is not identified, but may include impairment of mitochondrial or sarcomeric function, autophagy or angiogenesis, either as an on-target or off-target mechanism. Methods and Results We studied concentration-response curves and time courses for nine TKIs in three-dimensional, force generating engineered heart tissue (EHT) from neonatal rat heart cells. We detected a concentration- and time-dependent decline in contractile force for gefitinib, lapatinib, sunitinib, imatinib, sorafenib, vandetanib and lestaurtinib and no decline in contractile force for erlotinib and dasatinib after 96 hours of incubation. The decline in contractile force was associated with an impairment of autophagy (LC3 Western blot) and appearance of autophagolysosomes (transmission electron microscopy). Conclusion This study demonstrates the feasibility to study TKI-mediated force effects in EHTs and identifies an association between a decline in contractility and inhibition of autophagic flux

Irrigação de laranjeira com efluente de esgoto tratado; Na e K no solo.

Este trabalho teve o objetivo de avaliar a influência de diferentes lâminas de irrigação com efluente de esgoto urbano no teor de Na e K no solo. O delineamento experimental foi o de blocos completos casualizados com três repetições e quatro lâminas de irrigação com efluente de estação de tratamento de esgoto. Quatro diferentes lâminas foram fornecidas com base na evapotranspiração da cultura (ETc); i) 100% da ETc, ii) 125% da ETc, iii) 150% da ETc, e iv) 200% da ETc além do tratamento testemunha, sem irrigação (0% da ETc). A lâmina de 200% da ETc proporcionou a máxima concentração de Na trocável no solo para estas duas épocas. O índice pluviométrico da região em estudo (1200 mm ano-1) proporcionou a lixiviação do Na no perfil do solo. Reduções no conteúdo de K trocável no solo foram observadas com o aumento das lâminas de irrigação como consequencia do aumento do teor de Na no complexo de trocado solo e/ou pela lixiviação de K pelas lâminas excedentes (125, 150 e 200%). Com base nestes resultados e visando a otimização dos aspectos ambientais e da sustentabilidade da fertilidade do solo, sugere-se a irrigação com lâmina de 100% da necessidade hídrica da cultura, que possibilitará a menor entrada de Na no solo, além de reduzir as perdas de K

Neutrino production through hadronic cascades in AGN accretion disks

We consider the production of neutrinos in active galactic nuclei (AGN) through hadronic cascades. The initial, high energy nucleons are accelerated in a source above the accretion disk around the central black hole. From the source, the particles diffuse back to the disk and initiate hadronic cascades. The observable output from the cascade are electromagnetic radiation and neutrinos. We use the observed diffuse background X-ray luminosity, which presumably results {}from this process, to predict the diffuse neutrino flux close to existing limits from the Frejus experiment. The resulting neutrino spectrum is $E^{-2}$ down to the \GeV region. We discuss modifications of this scenario which reduce the predicted neutrino flux.Comment: 12 Pages, LaTeX, TK 92 0

Reconstructing the two right-handed neutrino model

In this paper we propose a low-energy parametrization of the two right-handed neutrino model, and discuss the prospects to determine experimentally these parameters in supersymmetric scenarios. In addition, we present exact formulas to reconstruct the high-energy leptonic superpotential in terms of the low-energy observables. We also discuss limits of the three right-handed neutrino model where this procedure applies.Comment: 28 pages, 4 figures. Typos corrected, references adde

The development of research supervisors’ pedagogical content knowledge in a lesson study project

In this study, we aimed to identify how the learning activities elicited in a lesson study project contributed to self-perceived change in supervisors’ pedagogical content knowledge (PCK). Lesson study is a method which combines both professional and educational development. During a lesson study project, teachers collaborate in a team and develop, teach, evaluate, and redesign a research lesson. During the 4-month lesson study project described here, four supervisors designed a protocol for research supervision meetings aimed at enhancing undergraduate students’ learning. During the project, they experimented with open questioning and giving positive feedback instead of giving instruction and explanations. A mixed-methods design was used in this study. Data on the supervisors’ learning activities and PCK were gathered using learner reports, video-recordings of meetings, and exit interviews. The analyses of these data showed that the lesson study project contributed to the development of the supervisors’ PCK on instructional strategies and student understanding. The learning activity that contributed most to these changes was reflecting on their own practice and that of their students

NICKEL DEPOSITION EFFECTS ON THE GROWTH OF CARBON NANOFIBERS ON CARBON PAPER

Summary Carbon nanofiber (CNF) growth has been achieved on carbon paper fibers via two nickel deposition routes: i. nickel nanoparticle-ethanol suspension casting, and ii. homogenous deposition precipitation (HDP) of nickel onto carbon paper. Nickel nanoparticles created regular tubular CNF whereas HDP of nickel forms mainly herringbone and platelet fiber structures. Average porosity of the carbon paper maintained over 50 % in both methods having more than 20 % CNF growth on one side of the carbon paper

On the benefits of rubbing salt in the cut: self-healing of saloplastic PAA/PAH compact polyelectrolyte complexes.

The inherent room temperature mending and self-healing properties of saloplastic PAA/PAH CoPECs are studied. After ultracentrifugation of PAA/PAH polyelectrolyte complexes, tough, elastic materials are obtained that undergo self-healing facilitated by salt. At intermediate salt concentrations the CoPECs remain elastic enough to recover their original shape while the chains are mobile enough to repair the cut, thus leading to actual self-healing behavior.journal articleresearch support, non-u.s. gov'tresearch support, u.s. gov't, non-p.h.s.2014 Apr 232014 01 29importe

Bioaffinity sensor based on nanoarchitectonic films: control of the specific adsorption of proteins through the dual role of an ethylene oxide spacer.

The identification and quantification of biomarkers or proteins is a real challenge in allowing the early detection of diseases. The functionalization of the biosensor surface has to be properly designed to prevent nonspecific interactions and to detect the biomolecule of interest specifically. A multilayered nanoarchitecture, based on polyelectrolyte multilayers (PEM) and the sequential immobilization of streptavidin and a biotinylated antibody, was elaborated as a promising platform for the label-free sensing of targeted proteins. We choose ovalbumin as an example. Thanks to the versatility of PEM films, the platform was built on two types of sensor surface and was evaluated using both optical- and viscoelastic-based techniques, namely, optical waveguide lightmode spectroscopy and the quartz crystal microbalance, respectively. A library of biotinylated poly(acrylic acids) (PAAs) was synthesized by grafting biotin moieties at different grafting ratios (GR). The biotin moieties were linked to the PAA chains through ethylene oxide (EO) spacers of different lengths. The adsorption of the PAA-EOn-biotin (GR) layer on a PEM precursor film allows tuning the surface density in biotin and thus the streptavidin adsorption mainly through the grafting ratio. The nonspecific adsorption of serum was reduced and even suppressed depending on the length of the EO arms. We showed that to obtain an antifouling polyelectrolyte the grafting of EO9 or EO19 chains at 25% in GR is sufficient. Thus, the spacer has a dual role: ensuring the antifouling property and allowing the accessibility of biotin moieties. Finally, an optimized platform based on the PAA-EO9-biotin (25%)/streptavidin/biotinylated-antibody architecture was built and demonstrated promising performance as interface architecture for bioaffinity sensing of a targeted protein, in our case, ovalbumin.journal articleresearch support, non-u.s. gov't2013 Jun 182013 02 11importe