Visible quantum plasmonics from metallic nanodimers

We report theoretical evidence that bulk nonlinear materials weakly interacting with highly localized plasmonic modes in ultra-sub-wavelength metallic nanostructures can lead to nonlinear effects at the single plasmon level in the visible range. In particular, the two-plasmon interaction energy in such systems is numerically estimated to be comparable with the typical plasmon linewidths. Localized surface plasmons are thus predicted to exhibit a purely nonclassical behavior, which can be clearly identified by a sub-Poissonian second-order correlation in the signal scattered from the quantized plasmonic field under coherent electromagnetic excitation. We explicitly show that systems sensitive to single-plasmon scattering can be experimentally realized by combining electromagnetic confinement in the interstitial region of gold nanodimers with local infiltration or deposition of ordinary nonlinear materials. We also propose configurations that could allow to realistically detect such an effect with state-of-the-art technology, overcoming the limitations imposed by the short plasmonic lifetime

Cavitating Pump Rotordynamic Test Facility at ALTA S.p.A.: Upgraded Capabilities of a Unique Test Rig

The paper illustrates the upgrades recently introduced in Alta’s Cavitating Pump Rotordynamic Test Facility in order to extend its experimental capabilities, with special reference to the addition of an auxiliary pump for testing of turbopump inducers over a wider range of flow coefficients, and the set-up of an original apparatus specifically designed for the characterization of the dynamic transfer matrices of cavitating inducers and turbopumps. Examples are presented of the improved capabilities of the facility

Rotordynamic Forces on a Three Bladed Inducer under Forced Whirl Motion Operating at Different Conditions

The paper illustrates the main results of an experimental campaign conducted in the CPRTF (Cavitating Pump Rotordynamic Test Facility) at ALTA S.p.A., aimed at characterizing the rotordynamic forces acting on a whirling three-bladed, tapered-hub, variable-pitch inducer, named DAPROT3. The forces acting on the impeller have been measured by means of a rotating dynamometer mounted just behind the inducer. The roles of the imposed whirl motion of the rotor, flow coefficient, cavitation number and liquid temperature have been investigated. The results have been obtained by means of a recent experimental technique, consisting in measuring the continuous spectra of the rotordynamic forces as functions of the whirl excitation frequency. This technique allows for extrapolating valuable information from the experiments by more accurately and rapidly characterizing the spectral behavior of these forces than can be obtained from a limited number of point experiments conducted at constant whirl frequency. Therefore, it is useful to better capture the complexity of the rotordynamic forces and assess their consequences on the stability of axial inducers

FEM modeling of a composite sandwich laminate with LS-DYNA for Aerospace applications

This project investigates how best to correctly predict the energy absorption of composite sandwich laminate under impact

Recreational exposure during algal bloom in carrasco beach, uruguay: A liver failure case report

In January 2015, a 20-month-old child and her family took part in recreational activities at Carrasco and Malvín beaches (Montevideo, Uruguay). An intense harmful algae bloom (HAB) was developing along the coast at that time. A few hours after the last recreational exposure episode, the family suffered gastrointestinal symptoms which were self-limited except in the child’s case, who was admitted to hospital in Uruguay with diarrhea, vomiting, fatigue, and jaundice. The patient had increased serum levels of liver enzymes and bilirubin and five days later presented acute liver failure. She was referred to the Italian Hospital in Buenos Aires, being admitted with grade II-III encephalopathy and hepatomegaly and requiring mechanical respiratory assistance. Serology tests for hepatitis A, B, and C, Epstein-Barr virus, and cytomegalovirus were negative. Laboratory features showed anemia, coagulopathy, and increased serum levels of ammonium, alanine aminotransferase (ALT), aspartate aminotransferase (AST), and bilirubin. Autoimmune Hepatitis Type-II (AH-II) was the initial diagnosis based on a liver kidney microsomal type 1 antibodies (LKM-1) positive result, and twenty days later a liver transplant was performed. The liver histopathology had indicated hemorrhagic necrosis in zone 3, and cholestasis and nodular regeneration, which were not characteristic of AH-II. LC/ESI-HRMS (liquid chromatography electrospray ionization high-resolution mass spectrometry) analysis of MCs in the explanted liver revealed the presence of Microsytin-LR (MC-LR) (2.4 ng·gr-1 tissue) and [D-Leu1]MC-LR (75.4 ng·gr-1 tissue), which constitute a toxicological nexus and indicate a preponderant role of microcystins in the development of fulminant hepatitis.Fil: Vidal, Flavia. Hospital Italiano; ArgentinaFil: Sedan, Daniela Yazmine. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Química. Centro de Investigaciones del Medio Ambiente; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: D'Agostino, Daniel. Hospital Italiano; ArgentinaFil: Cavalieri, María Lorena. Hospital Italiano; ArgentinaFil: Mullen, Eduardo. Hospital Italiano; ArgentinaFil: Parot Varela, María Macarena. Hospital Italiano; ArgentinaFil: Flores, Cintia. Instituto de Diagnóstico Ambiental y Estudios del Agua; EspañaFil: Caixach, Josep. Instituto de Diagnóstico Ambiental y Estudios del Agua; EspañaFil: Andrinolo, Dario. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Química. Centro de Investigaciones del Medio Ambiente; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Structural optimization of automotive chassis: theory, set up, design

Improvements in structural components design are often achieved on a trial-and-error basis guided by the designer know-how. Despite the designer experience must remain a fundamental aspect in design, such an approach is likely to allow only marginal product enhancements. A different turn of mind that could boost structural design is needed and could be given by structural optimization methods linked with finite elements analyses. These methods are here briefly introduced, and some applications are presented and discussed with the aim of showing their potential. A particular focus is given to weight reduction in automotive chassis design applications following the experience matured at MilleChili Lab

On the Preliminary Design and Performance Prediction of Centrifugal Turbopumps—Part 2

The ideal flow model for the preliminary design and performance prediction of radial turbopumps presented in the companion paper of the present volume (d’Agostino et al., 2017) is here interfaced with the calculation of the boundary layers inside the blade channels and other major forms of flow losses, with the aim of developing an effective tool for rapid parametric optimization of the machine performance and geometry under appropriate design constraints, such as assigned values of the specific speed, flow coefficient and blade solidity. A mixed-flow turbopump, with a six-bladed impeller, a vaneless diffuser, a single-spiral volute and nondimensional performance characteristics similar to those typically used in liquid propellant rocket engine feed systems, has been designed, parametrically optimized and manufactured in accordance with the indications of the present model. The pumping and suction performance of the machine have been determined in a series of tests in the Cavitating Pump Rotordynamic Test Facility (CPRTF). Under fully-wetted flow conditions the measured pumping characteristics of the machine (hydraulic head and efficiency as functions of the flow coefficient) proved to be in excellent agreement with the model predictions, thus successfully confirming the validity of the proposed model as an effective tool for rapid and efficient design of high-performance centrifugal turbopumps

Antimicrobial activity of supramolecular salts of gallium(III) and proflavine and the intriguing case of a trioxalate complex

The use of the gallium oxalate complex [Ga(ox)(3)](3-) as a building block in the formation of a drug-drug salt with the antimicrobial agent proflavine (PF) as its proflavinium cation (HPF+), namely [HPF](3)[Ga(ox)(3)]center dot 4H(2)O, is reported together with the preparation of the potassium salt K-3[Ga(ox)(3)] and the novel dimeric gallium(III) salt K-4[Ga-2(ox)(4)(mu-OH)(2)]center dot 2H(2)O. All compounds have been characterized by solid state methods, and their performance as antimicrobial agents has been evaluated by disk diffusion assay against the bacteria strains Pseudomonas aeruginosa ATCC27853, Staphylococcus aureus ATCC25923, and Escherichia coli ATCC25922. While the [HPF](3)[Ga(ox)(3)]center dot 4H(2)O drug-drug salt is effective against all three strains, the gallium oxalate salt K-3[Ga(ox)(3)] showed impressive selectivity towards P. aeruginosa, with little to no antimicrobial activity against the other two organisms. This work presents novel breakthroughs towards Ga based antimicrobial agents

Altered expression of mitochondrial and extracellular matrix genes in the heart of human fetuses with chromosome 21 trisomy

<p>Abstract</p> <p>Background</p> <p>The Down syndrome phenotype has been attributed to overexpression of chromosome 21 (Hsa21) genes. However, the expression profile of Hsa21 genes in trisomic human subjects as well as their effects on genes located on different chromosomes are largely unknown. Using oligonucleotide microarrays we compared the gene expression profiles of hearts of human fetuses with and without Hsa21 trisomy.</p> <p>Results</p> <p>Approximately half of the 15,000 genes examined (87 of the 168 genes on Hsa21) were expressed in the heart at 18–22 weeks of gestation. Hsa21 gene expression was globally upregulated 1.5 fold in trisomic samples. However, not all genes were equally dysregulated and 25 genes were not upregulated at all. Genes located on other chromosomes were also significantly dysregulated. Functional class scoring and gene set enrichment analyses of 473 genes, differentially expressed between trisomic and non-trisomic hearts, revealed downregulation of genes encoding mitochondrial enzymes and upregulation of genes encoding extracellular matrix proteins. There were no significant differences between trisomic fetuses with and without heart defects.</p> <p>Conclusion</p> <p>We conclude that dosage-dependent upregulation of Hsa21 genes causes dysregulation of the genes responsible for mitochondrial function and for the extracellular matrix organization in the fetal heart of trisomic subjects. These alterations might be harbingers of the heart defects associated with Hsa21 trisomy, which could be based on elusive mechanisms involving genetic variability, environmental factors and/or stochastic events.</p

PULCHER – Pulsed Chemical Rocket with Green High Performance Propellants: Project Overview

PulCheR is a research project co-funded by the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement n°313271, officially started as of January 1st, 2013. The project is mainly aimed at demonstrating the feasibility of a pulsed propulsion system in which the propellants are fed in the combustion chamber at low pressure and the thrust is generated by means of high frequency pulses, reproducing the defence mechanism of a notable insect: the bombardier beetle. The suitable design of the feeding lines, comprehensive of the injectors, allows the low pressure injection of the correct amount of propellants into the combustion chamber: the decomposition or combustion reaction increase the chamber pressure that rises to values much higher than the one at which the propellants are stored, exploiting the advantages of quasi constant volume combustion. The combustion products are accelerated through a convergent-divergent nozzle generating the thrust pulse and once the pressure inside the combustion chamber decreases under the injection pressure, the cycle can be repeated. The feasibility of this new propulsion concept will be investigated at breadboard level in both mono and bipropellant configurations through the design, realization and testing of a platform of the overall propulsion system including all its main components. In addition, the concept will be investigated using green propellants with potential similar performance to the current state-of-the-art for monopropellant and bipropellant thrusters. The present paper aims at presenting the main objectives and the current status of the PulCheR project