A reverse flow boiling thermosiphon loop : design and feasibility study.

Source: Masters Abstracts International, Volume: 40-07, page: . Thesis (M.A.Sc.)--University of Windsor (Canada), 1973

A pair of FRET dyes designed to measure nano-scale contact and the associated adhesion force

Interfacial adhesion is caused by intermolecular forces that only occur between surfaces at nano-scale contact (NSC) i.e., 0.1-0.4nm. To evaluate NSC and its influence on adhesion, F\"orster resonance energy transfer (FRET) spectroscopy has been used. FRET is a technique capable to measure nanometric distances between surfaces by taking advantage of the interaction amid some specific fluorescence molecules, named donor and acceptor. The F\"orster radius (R0) of the FRET pair indicates the distance detection range (0.5R0-2R0) of the system and, must be selected considering the final purpose of each study. Here, we propose a new FRET pair: 7-Amino-4-methyl-cumarin (C120) and 5(6)-Carboxy-2',7'-dichlor-fluorescein (CDCF) with high quantum yield (QY, QYC120=0.91 and QYCDCF=0.64) and a distance range of 0.6-2.2nm (0.1 mM) specifically developed to measure NSC between soft surfaces. For this, polymeric thin films were bonded using different loads, from 1.5 to 150 bar, to create different degrees of NSC, analyzed by FRET spectroscopy, and later pulled apart to measure their interfacial separation energy (adhesion force). Our experiments showed that NSC increases with the applied pressure in the bonded thin films, leading to higher FRET intensity and adhesion force/separation energy. Thus, we have validated a new FRET pair, suitable to measure the degree of NSC between surfaces and establish a linear relationship between FRET and adhesion force; which can be of interest for any type of study with soft materials interfaces that include NSC and its influence on adhesion, as sealants, adhesives or sensors

Secure extension of FPGA general purpose processors for symmetric key cryptography with partial reconfiguration capabilities

International audienceIn data security systems, general purpose processors (GPPs) are often extended by a cryptographic accelerator. The paper presents three ways of extending GPPs for symmetric key cryptography applications. Proposed extensions guarantee secure key storage and management even if the system is facing protocol, software and cache memory attacks. The system is partitioned into processor, cipher, and key memory zones. The three security zones are separated at protocol, system, architecture and physical levels. The proposed principle was validated on Altera NIOS II, Xilinx MicroBlaze and Microsemi Cortex M1 soft core processor extensions. We show that stringent separation of the cipher zone is helpful for partial reconfiguration of the security module, if the enciphering algorithm needs to be dynamically changed. However, the key zone including reconfiguration controller must remain static in order to maintain the high level of security required. We demonstrate that the principle is feasible in partially reconfigurable field programmable gate arrays (FPGAs) such as Altera Stratix V or Xilinx Virtex 6 and also to some extent in FPGAs featuring hardwired general purpose processors such as Cortex M3 in Microsemi SmartFusion FPGA. Although the three GPPs feature different data interfaces, we show that the processors with their extensions reach the required high security level while maintaining partial reconfiguration capability

London’s rivers: a collection of landscape drawings

Textos en inglés, español y catalán[EN]The 22 drawings that form the series London’s Rivers were designed in Elche (Spain) and London between January and July 2012 and were shown at the Aifos Room of the University of Alicante between February and March 2013, in an exhibition entitled Gardens Materials Landscapes. They were published in a CD-ROM, in digital format. The technique used is acrylic on paper Canson Figueras acid free, 290 gr / m2; the size of each design is 190 x 240 mm. Additionally, 20 further drawings are included in an Addendum. These were designed in the winter and spring of 2014, and are by way of thanks to those friends whose texts accompany the original series London’s Rivers (2012) published here. The technique used is acrylic on canvas sketch pads made from cotton fabric, 380 gr / m2; the size of each design is 210 x 297 mm

ATP-sensitive potassium channels modulate in vitro tocolytic effects of β2- adrenergic receptor agonists on uterine muscle rings in rats in early but not in late pregnancy

Aim To investigate whether ATP-sensitive potassium (KATP) channels modulate the tocolytic effect of β2-adrenergic receptor (β2-AR) agonists (ritodrine and salmeterol) in early- pregnant (day 6) and late-pregnant (day 22) rat uterus in vitro, in order to examine the relation between the KATP channel sulphonylurea-binding regulatory subunit (SUR) expression and pharmacological reactivity of β2-AR agonists. Methods The tocolytic effects of ritodrine and salmeterol (10-10-10-5 M) on spontaneous rhythmic contractions were investigated cumulatively, alone, or in the presence of the KATP channel blocker glibenclamide (10-6 M) and the KATP channel opener pinacidil (10-9-10-7 M) after 5-min preincubation. Results β2-AR agonist induced myometrial relaxation was inhibited by glibenclamide and enhanced by pinacidil on day 6, when SUR1 expression levels were high. Neither glibenclamide nor pinacidil mediated tocolytic effect was measured on day 22. Conclusion Low expression of the KATP channels at the end of gestation may facilitate enhanced excitability and contractility in the rat myometrium. The combination of a betamimetic and a KATP channel opener will therefore not be of therapeutic relevance in the treatment of preterm delivery

ITERATIVE NONLINEAR MODELING OF EXHAUST PRESSURE PULSES FROM A SMALL ROTARY ENGINE.

An experimental study was undertaken to investigate some of the factors affecting the behaviour of pressure variations in a straight exhaust pipe attached to a rotary engine. The investigation involved the measurement of engine load, speed, fuel consumption, combustion air properties and flow rate, mean static pressure near the exhaust port, mean temperatures at two locations in the exhaust pipe and transient gas pressures at two locations in the exhaust pipe. A theoretical, nonlinear model of the particle velocity of a gas excited by an acoustic wave propagation was modified to model the transient pressure behaviour of an acoustic wave. The model was correlated with the transient pressure measurements with the aid of an iterative correlation technique and digital signal processing. Standard curve fitting procedures were used to relate the various measurements as functions of engine speed. The iterative procedure outlined has been found to be a good method for the treatment of data which cannot be correlated by standard linearization and regression techniques. Further, the analysis indicates that the model correlates very well with the pressure pulse created by the rotor chamber blow-down. It is also possible to predict the length through which the pressure pulse must travel before the leading portion of the pulse distorts into a shock wave.Dept. of Mechanical, Automotive, and Materials Engineering. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1983 .G376. Source: Dissertation Abstracts International, Volume: 44-09, Section: B, page: 2864. Thesis (Ph.D.)--University of Windsor (Canada), 1983

Sustained monomorphic left ventricular outflow tract tachycardia early after aortic valve replacement

Sustained monomorphic ventricular tachycardia (VT) after valve surgery is uncommon. Cases of focal VT or bundle-branch re-entry after aortic valve surgery have been reported. We present the case of a 60 year-old patient with an incessant outflow tract VT early after aortic valve replacement. We suggest the disease process affecting the valve and adjacent area, and/or the surgical procedure, might somehow relate to VT substrate adjacent to the aortic annulus

HAT-P-9b: A Low Density Planet Transiting a Moderately Faint F star

We report the discovery of a planet transiting a moderately faint (V=12.3 mag) late F star, with an orbital period of 3.92289 +/- 0.00004 days. From the transit light curve and radial velocity measurements we determine that the radius of the planet is R_p = 1.40 +/- 0.06 R_Jup and that the mass is M_p = 0.78 +/- 0.09 M_Jup. The density of the new planet, rho = 0.35 +/- 0.06 g cm^{-3}, fits to the low-density tail of the currently known transiting planets. We find that the center of transit is at T_c = 2454417.9077 +/- 0.0003 (HJD), and the total transit duration is 0.143 +/- 0.004 days. The host star has M_s = 1.28 +/- 0.13 M_Sun and R_s = 1.32 +/- 0.07 R_Sun.Comment: Submitted to ApJ; V2: Replaced with accepted versio

Test and Analysis of an Inflatable Parabolic Dish Antenna

NASA is developing ultra-lightweight structures technology for large communication antennas for application to space missions. With these goals in mind, SRS Technologies has been funded by NASA Glenn Research Center (GRC) to undertake the development of a subscale ultra-thin membrane inflatable antenna for deep-space applications. One of the research goals is to develop approaches for prediction of the radio frequency and structural characteristics of inflatable and rigidizable membrane antenna structures. GRC has teamed with NASA Langley Research Center (LaRC) to evaluate inflatable and rigidizable antenna concepts for potential space missions. GRC has completed tests to evaluate RF performance, while LaRC completed structural tests and analysis to evaluate the static shape and structural dynamic responses of a laboratory model of a 0.3 meter antenna. This paper presents the details of the tests and analysis completed to evaluate the radio frequency and structural characteristics of the antenna