Conduction state transition induced by solitons in a graphene junction at room temperature

The aim of this research was the study of the transition between high and low electrical resistivity states of two overlapped graphene layers when subjected to short electromagnetic pulses (soliton waves). These transitions have already been previously observed by the authors in experiments carried out with different conductors, separated by a tiny insulating layer. The choice of a highly ordered material, such as graphene, was justified by the attempt to achieve greater stability and reproducibility of these transitions. What has been observed is an instantaneous reversible transition of the graphene overlapped layers to/from a state of insulator with resistance in the order of Mohms from/to a state of resistance of few ohms or, in some cases, of zero ohms. The transition from a high resistance state to a lower one requires EM pulses of different polarity than the transition from a low resistivity state to a higher one. Some intermediate relatively stable states have also been observed

Risk Allocation in Toll Highway Concessions in Spain: Lessons from Economic Recession

Spain has a long tradition of encouraging toll highways by granting concessions to private companies. Concessions in Spain have been characterized by a willingness to transfer considerable risk to the private sector. Traffic demand, acquisition of the right-of-way, and financial risk have often been allocated to the private sector. From 1996 to 2011, 16 toll highway concessions, covering a total distance of 835 km, were awarded by the central government of Spain with this approach. Some of those highways started their operations just before the economic recession began. The recession had negative consequences for Spain's economy. The gross domestic product per capita plummeted, and the unemployment rate increased from 9% to 20% of the working population in just 2 years. The recession also had severe consequences for the economic performance of toll highway concessions. Traffic levels declined at a much greater rate than did the gross domestic product. In addition, the conditions imposed by the financial markets on borrowers became much stricter because of the liquidity crisis. This study analyzes the impact that the economic recession ultimately had on the performance of toll highway concessions in Spain and the actions that the government adopted to avoid the bankruptcy of the concessionaires. It was found that the economic recession helped identify some deficiencies in how risk had been allocated in Spain. The measures that both Spain and the European Union are adopting so as to improve risk allocation are discussed

Interpretation of the behaviour of compacted soils using cam-clay extended to unsaturated conditions

This paper is focused on the interpretation of experimental results obtained at the Department of Geotechnical Engineering of the University of Naples Federico II (Italy) to investigate the effects of partial saturation on the volumetric behaviour and the initial shear stiffness of a compacted silt. Tests were performed by using suction-controlled triaxial and resonant column cells. Herein, the compatibility of the results with a Single Stress Model (SSM) is discussed. The SSM allows to highlight that suction can have two effects on the mechanical behaviour of an unsaturated soil: it increases the average volumetric stress acting on the soil skeleton and it has a sort of cementing effect on the soil packing (hardening and cementation)

Controlled trial with brinerdin : a new antihypertensive

A double-blind study on 40 ambulant, mild to moderate hypertensive patients aged from 35-67 years is presented. After a dose-adjustment period and a 3-week wash-out the patients were randomized into 2 groups each on active drug and placebo respectively. Regular physical and laboratory examinations were made. The Brinerdin group showed a highly significant fall in blood pressure. In all cases the fall was gradual without sudden fluctuation. By comparison the placebo group showed only insignificant changes in blood pressure. At the effective dosage of 1-3 tablets daily there were no untoward side-effects. As with all saluretic drugs some patients tended to have slightly raised uric acid levels. The study demonstrates that at a dosage of 1-3 tablets per day Brinerdin is an effective anti-hypertensive agent. In all cases comparison with placebo showed a highly significant difference in favour of Brinerdin.peer-reviewe

Application to a compacted soil of a Cam Clay model extended to unsaturated conditions

This paper presents an interpretation of experimental results obtained at the Department of Geotechnical Engineering of the Università di Napoli Federico II. The results are part of an extensive program carried out to investigate the effects of partial saturation on the volumetric behaviour and on the initial shear stiffness of a compacted silt. Tests were performed using two suction-controlled devices, a triaxial cell and a Resonant Column Torsional Shear (RCTS) cell. The compatibility of experimental data with a Bishop Stress Model (BSM) is discussed in the paper. The BSM permits to highlight the two main effects of suction on soil behaviour: the increase of the average stress acting on the soil skeleton and the hardening - cementing of the soil packing. Hydraulic hysteresis is included in the definition of the water retention curve so that its effects, such as the irreversible component of volume change recorded during drying paths, are automatically incorporated in the predictions of the model

THE MOSAIC OF THE FRIGIDARIUM OF “VILLA BONANNO” IN PALERMO: MINERALOGICAL AND PETROGRAPHIC ANALYSES FOR IN SITU CONSERVATION AND RESTORATION INTERVENTIONS

The topic of this study was the mineralogical and petrographic characterization of bedding mortars (made of different layers) and tesserae of Roman age (3rd century A.D.), taken from the mosaic of the Frigidarium of “Villa Bonanno”, brought to light by archaeological excavations conducted in the historical centre of Palermo. The collected samples have been analysed by thin-section optical microscopy (PLM), and scanning electron microscopy coupled with energy dispersive spectrometry (SEM-EDS). The study was aimed to define the “recipe” (composition of aggregate and binder, aggregate size distribution, aggregate/binder ratio), in order to assess the provenance of raw materials (supply site/area) and to acquire useful information in order to formulate "restoration mortars" that should be most comparable with the original ones, for replacements and/or integration. Rock types constituting the coloured tesserae were also characterized by thin-section optical microscopy. The mineralogical and petrographic investigations allowed establishing two different recipes used for the formulation of the studied mortars in terms of both compositional and textural features. The aggregate is composed by diverse proportions of detritic calcareous granules (both bioclasts and limestone fragments deriving from the local outcropping biocalcarenites and limestones), siliceous sand (monocrystalline quartz, chert and quartzarenite fragments), volcanic ash (pozzolana) and sometimes cocciopesto. The resulting hydraulic binder was the product of the „pozzolanic reaction‟ between volcanic ash and the aerial lime (specifically made by the calcination of locally available magnesian limestone or dolostone). The coloured tesserae can be all classified as compact limestones of Mesozoic or Cenozoic age, likely of local provenance

Can a systems approach reduce adverse outcomes in patients with dementia in acute settings? (innovative practice)

People with dementia experience adverse outcomes such as pressure sores during their stay in acute hospitals. The application of a systems approach in an acute setting places an emphasis on the patient’s journey in addition to the organisational factors that are present within a hospital context. This article draws upon principles obtained from a theoretical model, which was extracted from the work of Edwards (1972), Hawkins (1987) and Zecevic et al. (2007), in order to illustrate how the application of a novel systems approach (human interaction, environment, equipment and policy) could be used in acute hospital settings to reduce adverse health outcomes by using an imaginary patient with dementia

Wavefront correction with a ferrofluid deformable mirror: experimental results and recent developments

We present the research status of a deformable mirror made of a magnetic liquid whose surface is actuated by a triangular array of small current carrying coils. We demonstrate that the mirror can correct a 11 microns low order aberrated wavefront to a residual RMS wavefront error 0.05 microns. Recent developments show that these deformable mirrors can reach a frequency response of several hundred hertz. A new method for linearizing the response of these mirrors is also presented.Comment: To appear in "Ground-based and Airborne Instrumentation for Astronomy II" SPIE conference, Marseille, 23-28 June 200

Numerical Assessment on the Influence of Engine Calibration Parameters on Innovative Piston Bowls Designed for Light-Duty Diesel Engines

The optimization of the piston bowl design has been shown to have a great potential for air–fuel mixing improvement, leading to significant fuel consumption and pollutant emissions reductions for diesel engines. With this aim, a conventional re-entrant bowl for a 1.6 L light-duty diesel engine was compared with two innovative piston designs: a stepped-lip bowl and a radial-bumps bowl. The potential benefits of these innovative bowls were assessed through 3D-CFD simulations, featuring a calibrated spray model and detailed chemistry. To analyse the impact of these innovative designs, two different engine operating conditions were scrutinized, corresponding to the rated power and a partial load, respectively. Under the rated power engine operating condition, a start of injection sensitivity was then carried out to assess the optimal spray–wall interaction. Results highlighted that, thanks to optimal injection phasing, faster mixing-controlled combustion could be reached with both the innovative designs. Moreover, the requirements in terms of swirl were also investigated, and a higher swirl ratio was found to be necessary to improve the mixing process, especially for the radial-bumps design. Finally, at part-load operating conditions, different exhaust gas recirculation (EGR) rates were analysed for two injection pressure levels. The stepped-lip and radial-bumps bowls highlighted reduced indicated specific fuel consumption (ISFC) and soot emissions values over different rail pressure levels, guaranteeing NOx control thanks to the higher EGR tolerance compared with the re-entrant bowl. The results suggested the great potential of the investigated innovative bowls for improving efficiency and reducing emissions, thus paving the way for further possible optimization through the combination of these designs