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Purpose Intensity-based image registration has been proven essential in many applications accredited to its unparalleled ability to resolve image misalignments. However, long registration time for image realignment prohibits its use in intra-operative navigation systems. There has been much work on accelerating the registration process by improving the algorithm’s robustness, but the innate computation required by the registration algorithm has been unresolved. Methods Intensity-based registration methods involve operations with high arithmetic load and memory access demand, which supposes to be reduced by graphics processing units (GPUs). Although GPUs are widespread and affordable, there is a lack of open-source GPU implementations optimized for non-rigid image registration. This paper demonstrates performance-aware programming techniques, which involves systematic exploitation of GPU features, by implementing the diffeomorphic log-demons algorithm. Results By resolving the pinpointed computation bottlenecks on GPU, our implementation of diffeomorphic log-demons on Nvidia GTX Titan X GPU has achieved ~ 95 times speed-up compared to the CPU and registered a 1.3-M voxel image in 286 ms. Even for large 37-M voxel images, our implementation is able to register in 8.56 s, which attained ~ 258 times speed-up. Our solution involves effective employment of GPU computation units, memory, and data bandwidth to resolve computation bottlenecks. Conclusion The computation bottlenecks in diffeomorphic log-demons are pinpointed, analyzed, and resolved using various GPU performance-aware programming techniques. The proposed fast computation on basic image operations not only enhances the computation of diffeomorphic log-demons, but is also potentially extended to speed up many other intensity-based approaches. Our implementation is open-source on GitHub at https://bit.ly/2PYZxQz.

We present a digital platform-based lock-in detection scheme to improve the gas sensing performance of a spectrometer. A numerically-controlled oscillator serves as reference clock to trigger the supercontinuum source and to demodulate the detector signal.

Supporting a high level of parallelism for statistical algorithms on FPGAs is often hindered by the uncertainty of random memory access and the associated difficulty of scheduling at runtime. By exploiting the statistical properties to tolerate memory request reordering and droppage, speed enhancement and resource reduction of the design can be optimized, leading to a more efficient and parallelizable design. This paper introduces a novel lossy multiport memory capable of high memory bandwidth, providing concurrent accesses to a single address space through multiple ports. The proposed architecture contains parallel memory banks connected by lossy switch networks to multiple input ports and local ring buffers. For 4 parallel read/write ports, our design reduces BRAM usage by 68% while having the operating frequency increased by 50% as compared to state-of-the-art memory designs. The drop rate of the design is 2% under full port utilization, and is reducible without altering the architecture at runtime. With a simple and scalable structure, this memory architecture can be scaled up to 64 parallel read/write ports and beyond, which outperforms most of the existing designs. Experiments show that this lossy memory can reduce slice usage by 90.8 times for random forest training and data compression, with a reduction in accuracy of only 2%.

The influence of microstructure on the dwell fatigue crack growth behaviour of an advanced nickel-based superalloy was investigated at a temperature of 700°C. Microstructural variations were induced by heat treatment variables: different cooling rates of quenching from super-solvus solution heat treatment, 0.7 and 1.8°Cs−1, and an addition of a high temperature stabilisation heat treatment (2h at 857°C) between the solution treatment and the final ageing treatment. With a one hour dwell introduced at the peak load of the fatigue cycle, such different microstructural conditions can lead to a difference of up to two orders of magnitude in crack growth rates in air, when compared to those obtained under baseline fatigue loading. By performing such dwell fatigue and baseline fatigue tests in vacuum, it is confirmed that such increases in crack growth rates under dwell fatigue loading in air are mainly environmentally related. Transmission electron microscopy (TEM) was utilised to analyse both crack tip oxides and associated deformation mechanisms in the matrix. A novel mechanism taking into account competing interactions of crack tip oxidation (leading to increases in crack growth rates) and stress relaxation (leading to decreases in crack growth rates) is outlined.

Resumen del trabajo presentado al 14th Ceramics Congress (CIMTEC), celebrado en Perugia (Italia) del 4 al 4 de junio de 2018., Concrete is essential in our society for housing and infrastructure. Because of the large amount of concrete and cement yearly consumed, respectivelly 30 Btn/y and 4.5 Bt/y, the cement industry finally accounts for 8-9% of CO2 worldwide emissionsAlkali-activated materials have been deeply studied as an alternative and more ecoefficient cement. These cements are produced by mixing an aluminosilicate (by-products such as blast furnace slag or fly ash) with a highly alkaline solution. Concrete produced with these cements have proven to have suitable enginering properties and high durability against chemical attack. However, their poor rheological properties represents one of the barriers for the implementation of these alternative cements, mainly when sodium silicate is used as an activator. In this paper, give an overview of the impact of superplasticizers with different molecular structures on the rheological properties of alkali-activated slag cements. Results have shown the incompatibility of most superplasticizers with these alternative cements. Furthermore, the mechanism of action of the working admixtures have been resolved by a combination of experimental and modeling techniques. In particular, the obtained results concluded that the dispersion mechanism is dominated by the steric repulsión, an important design criterion for improving the rheological behaviour.

Aerosol mediated delivery of nano based therapeutics to the lung has emerged as a promising alternative for treatment and prevention of lung diseases. Superparamagnetic iron oxide nanoparticles (SPIONs) have attracted significant attention for such applications due to their biocompatibility and magnetic properties. However information is lacking about the characteristics of nebulized SPIONs for use as a therapeutic aerosol. To address this need we conducted a physicochemical characterization of nebulized Rienso a SPION based formulation for intravenous treatment of anemia. Methods: Four different concentrations of SPION suspensions were nebulized with a one jet nebulizer. Particle size was measured in suspension by transmission electron microscopy (TEM) photon correlation spectroscopy (PCS) and nanoparticle tracking analysis (NTA) and in the aerosol by a scanning mobility particle sizer (SMPS). Results: The average particle size in suspension as measured by TEM PCS and NTA was 9±2?nm 27±7?nm and 56±10?nm respectively. The particle size in suspension remained the same before and after the nebulization process. However after aerosol collection in an impinger the suspended particle size increased to 159±46?nm as measured by NTA. The aerosol particle concentration increased linearly with increasing suspension concentration and the aerodynamic diameter remained relatively stable at around 75?nm as measured by SMPS. Conclusions: We demonstrated that the total number and particle size in the aerosol were modulated as a function of the initial concentration in the nebulizer. The data obtained mark the first known independent characterization of nebulized Rienso and as such provide critical information on the behavior of Rienso nanoparticles in an aerosol. The data obtained in this study add new knowledge to the existing body of literature on potential applications of SPION suspensions as inhaled aerosol therapeutics.

This paper presents a mechanism-based approach for modelling the thermomechanical behaviour of a Cr-Mo-V steel. A set of unified viscoplastic constitutive equations were employed to model dislocation density, recrystallisation and grain size during deformation. The evolution of dislocation density accounts for the build-up of dislocations due to plastic strain, the static and dynamic recovery and the effect of recrystallisation. Recrystallisation occurs when a critical dislocation density is reached after an incubation time, and grain size becomes smaller after such event. Gleeble compression tests were used to obtain Stress-strain curves and evaluate the microstructural evolution at different temperature and strain rate, and the material constants for the model were determined from the experimental data. Copyright © 2010 MS&T10®.

Carotenoids and retinoids have been reported to reduce gastrointestinal mucosa damage from a variety of irritants. We performed double-blind, placebo-controlled endoscopic trial to evaluate the effect of chronic beta-carotene supplementation upon the gastric mucosal response to acute aspirin injury. Six subjects taking chronic beta-carotene and six taking placebo each ingested 650 mg of aspirin after an endoscopy confirmed normal gastric mucosa. Three hours later, mucosal lesions were counted at repeat endoscopy. beta-Carotene did not prevent acute mucosal injury better than placebo.

In this work, the novel fabrication and characterization of elastomeric piezoelectric nanocomposites are explored. Fabrication methods explored herein utilize ball milled barium titanate powder dispersions, along with double walled carbon nanotubes which are dispersed in toluene though the use of an ultrasonic probe. Test devices are then constructed with electrodes made from evaporated gold on polyimide foils and protective dielectrics of pristine PDMS. Two different device construction methods are explored utilizing both direct contact bonding and plasma bonding of the active composite layers to the dielectric/electrode. Test samples are evaluated through the use of a dedicated Berlincourt type piezoelectric d33 meter. © Published under licence by IOP Publishing Ltd.

CuO powders with a high specific surface area are shown to be able to produce H2O2 in aqueous solution under simulated light irradiation. The highest rate of peroxide production was observed under mild experimental conditions using O2 and a large surface area photocatalyst CuO irradiated with a solar simulator having light intensities between 60 and 90 mW/cm2. The CuO employed had a specific surface area (SSA) of 64.8-70.1 m2/g and was prepared in a tubular furnace by controlled thermal decomposition of precipitated copper oxalate. The CuOparticles produced were 1 μmcubes with primary particles around 15 nm. No peroxide was produced under the same conditions with commercial CuO, with SSA 200 times lower. The CuO synthesized during this work was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), specific surface area [Brunauer-Emmett-Teller (BET)], porosity, and X-ray photoelectron spectroscopy (XPS). From XPS, it was observed that only CuII was present in the unused and used CuO. This indicates that the redox transient species involving other Cu oxidation states disappear very fast during the reaction, regenerating CuII during H2O2 production. Diverse experiments provided some evidence for the possible interfacial reaction mechanism leading to H2O2, following the initial step of O2-‚ formation on the CuO surface under irradiation with photons, with energies exceeding the band gap of CuO. A photocatalyzed degradation of a concentrated 4-chlorophenol (4-CP) solution was observed under solar-simulated light in the presence of CuO.

Ozone prodn. in 5M H2SO4 with Ti/IrO2/SnO2 - Sb2O5 electrodes was studied. Electrodes were prepd. at 550 Deg by spray pyrolysis of a soln. of precursors contg. tin and antimony chlorides. The aim of this work was to elucidate the mechanism of activation and deactivation of Ti/IrO2/SnO2-Sb2O5 electrodes for ozone prodn. Under galvanostatic conditions the anodic potential and O3 prodn. increases firstly reaching a max. then suddenly decrease. The authors explain this observation by considering that the SnO2 layer prepd. by spray pyrolysis is under stoichiometric for oxygen. During the activation SnO2 becomes stoichiometric. This condition is necessary for ozone prodn. XRD anal. showed no modification of the structure of the bulk during ozone prodn. Nevertheless XRF anal. revealed an inhomogeneity of the at. Sb/Sn ratio on the surface of the electrode leading to pitting corrosion which is responsible of the deactivation of the electrode. [on SciFinder (R)]

NOVELTY - Production of a component (23) coated with a heat protection layer (21) and having a high thermal load capacity comprises applying an adhesion layer (22) containing aluminum on the surface of the component, and applying the heat protection layer on the adhesion layer. A thin auxiliary layer (24) made from nano-crystalline alpha-Al2O3 is formed on the adhesion layer before the heat protection layer is applied. USE - Used in the production of gas turbines. ADVANTAGE - The component has a long service life. DETAILED DESCRIPTION - Preferred Features: The auxiliary layer is directly deposited on the surface of the adhesion layer. The component is made from a super alloy. The adhesion layer is made from an MCrAlY alloy (where M = Fe, Co and/o Ni). The heat protection layer is made from Y-stabilized zirconium dioxide. The auxiliary layer is approximately 10 mum thick.

The question whether beta-tricalcium phosphate (beta-TCP) can form a solid solution with beta-calcium pyrophosphate (beta-CPP) and/or hydroxyapatite (HA) has still not been solved. For this reason, wet-chemically synthesized beta-TCP powders with only 20 ppm Sr (among 43 tested elements) and with different HA and beta-CPP contents, or in other words Ca/P molar ratios, were used. The graphical relationship between these various Ca/P molar ratios determined by X-ray diffraction and by inductively-coupled plasma mass spectrometry showed no discontinuity, indicating the absence of a solid solution between beta-TCP and beta-CPP or HA. Analysis of the beta-TCP lattice parameters as a function of the Ca/P molar ratio revealed a discontinuity at a Ca/P molar ratio of 1.500 and a maximum microstrain. These results indicated that at least two beta-TCP structures co-existed, with variable mixing ratios depending on the Ca/P molar ratio, and with a distinct jump at a Ca/P molar ratio of 1.500.

Adsorption isotherms of carboxylate type superplasticizers with different architectures have been measured on MgO considered as a non-reactive model powder. This system allowed us to study the influence of pH, electrolyte type, concentration and ionic strength on the adsorbed amount. On same MgO powder, we have measured the zeta potential variations by adding increasing amounts of superplasticizers. Most of the isotherms initially exhibit a linear section followed by a hyperbolic behavior which can be fitted by a function identical to the Langmuir equation. The slope of the linear part allowed us to define the affinity of the superplasticizers for MgO surfaces and with the asymptotic value of the hyperbolic function a plateau value for the adsorption. The results are discussed taking into consideration the molecular parameters of the superplasticizers, such as the molar mass, backbone chain and side chain lengths. The mechanisms of fixation of the superplasticizers at the surface are also discussed.