Effect of boron carbide nanoparticles on the fire reaction and fire resistance of carbon fiber/epoxy composites

In this work the thermal behavior of a carbon-fiber composite impregnated with nano sized boron carbide based nanocomposites was investigated. First of all, the good dispersion and distribution of the particles in the matrix confirmed the effectiveness of the mechanical mixing. The presence of the ceramic filler did not affect the viscosity and the workability of the blends or the mechanical properties of the composites. The thermal stability of the fiber-reinforced materials was investigated by thermo-gravimetrical analysis in air and nitrogen. Their fire reaction was studied at different heat fluxes (35 and 50 kW/m²) by cone calorimeter while the flame resistance was evaluated trough residual mechanical properties after the exposition of the specimens to a direct flame of a torch (heat flux of 500 kW/m²). The experimental data suggested that boron carbide allows maintaining a residual structural integrity of the material after burning because of the chemical reactions that occur in the filler at high temperatures; the presence of boron carbide reduces the peak of heat release rate especially at higher heat-fluxes and improves the thermal stability of the composite hindering and retarding the thermal oxidation of the carbon fibers.     

Analysis and simulation of an industrial vegetable oil refining process

This work focuses on the performance analysis of an industrial vegetable oil refinery. Using a commercial process simulator, a process model was developed and validated against actual vegetable oil refinery field data. The simulator allowed investigating both energy and safety aspects related to the presence of residual extraction solvent (extraction grade hexane) in the processed crude vegetable oil. The critical nodes for hexane accumulation in the process were evaluated, both considering ordinary operative conditions and undesired process deviations due to increase of the hexane content. In this latter case, the control actions able to restore the normal operation were simulated, in terms of increased utility consumption (e.g., motive steam for ejectors and cooling water) or by modifying and optimizing equipment operating conditions. Finally, the possibility of flammable mixtures formation inside process vent pipes, caused by the entrainment of air due strong vacuum conditions, was also investigated.     

Modeling Nonlinear Systems by Volterra Series

The Volterra-series expansion is widely employed to represent the input-output relationship of nonlinear dynamical systems. This representation is based on the Volterra frequency-response functions (VFRFs), which can either be estimated from observed data or through a nonlinear governing equation, when the Volterra series is used to approximate an analytical model. In the latter case, the VFRFs are usually evaluated by the so-called harmonic probing method. This operation is quite straightforward for simple systems but may reach a level of such complexity, especially when dealing with high-order nonlinear systems or calculating high-order VFRFs, that it may loose its attractiveness. An alternative technique for the evaluation of VFRFs is presented here with the goal of simplifying and possibly automating the evaluation process. This scheme is based on first representing the given system by an assemblage of simple operators for which VFRFs are readily available, and subsequently constructing VFRFs of the target composite system by using appropriate assemblage rules. Examples of wind and wave-excited structures are employed to demonstrate the effectiveness of the proposed technique.     

Parallel and high sensitive photonic crystal cavity assisted read-out for DNA-chips

In this work we propose a new technological approach aimed at improving the performances of DNA-chips in terms of detection sensitivity, signal-to-noise ratio and parallel analyses (spatial and spectral). It is based on the efficient enhancement of markers fluorescence through the insertion of photonic crystal nanocavities (PhC) in DNA-chips, thus giving higher sensitivity and allowing detection of small amounts of target biomolecules in the investigated solution. Moreover, this strategy univocally associates a specific emission wavelength to a specific nanocavity (and to the bio-probe immobilized on it), therefore allowing to infer the presence of a determined element in the solution by a simple spectral analysis of the optical response of the read-out region. This guarantees parallel detection of multiple elements and faster analysis time. The proposed 2D-PhC cavity assisted bio-chip read-out can be easily extended from DNA to a wide range of biomolecules, such as proteins, antibodies, aptamers, receptors.     

Experimental measurement and numerical simulation of horizontal-coupled slinky ground source heat exchangers

Results from both experimental measurements and 3D numerical simulations of Ground Source Heat Pump systems (GSHP) at a UK climate are presented. Experimental measurements of a horizontal-coupled slinky GSHP were undertaken in Talbot Cottage at Drayton St Leonard site, Oxfordshire, UK. The measured thermophysical properties of in situ soil were used in the CFD model. The thermal performance of slinky heat exchangers for the horizontal-coupled GSHP system for different coil diameters and slinky interval distances was investigated using a validated 3D model. Results from a two month period of monitoring the performance of the GSHP system showed that the COP decreased with the running time. The average COP of the horizontal-coupled GSHP was 2.5. The numerical prediction showed that there was no significant difference in the specific heat extraction of the slinky heat exchanger at different coil diameters. However, the larger the diameter of coil, the higher the heat extraction per meter length of soil. The specific heat extraction also increased, but the heat extraction per meter length of soil decreased with the increase of coil central interval distance.     

Digital-sampling systems in high-resolution and wide dynamic-range energy measurements: Finite time window, baseline effects, and experimental tests

Fast digital sampling and signal processing of the output of charge-sensitive preamplifiers connected to solid-state detectors, used in nuclear physics experiments, constitute effective replacements of the standard analog methods. If high-resolution and high-speed sampling Analog to Digital Converters (ADCs) are used, both the energy and timing resolution performances of the detector can be effectively exploited. The choice of a particular fast ADC in these applications is strictly related to the desired resolution and dynamic range of the system. In this paper a quantitative evaluation of system resolution is carried out—the results of [L. Bardelli and G. Poggi, Digital sampling-systems in high-resolution and wide dynamic-range energy measurements: comparison with peak sensing ADCs, this issue] are extended taking into account not only the detector noise, the digitizer properties, and the digital shaping, but also the use of a finite time interval for both baseline evaluation and digital shaping. The resulting performances are expressed using the parameter PSENOB [L. Bardelli, G. Poggi, Digital sampling-systems in high-resolution and wide dynamic-range energy measurements: comparison with peak sensing ADCs, this issue] and two additional correction terms. The effects due to ADC non-linearities are also briefly addressed. Simulations are presented to validate the proposed recipe. Experimental tests using a germanium detector in a wide dynamic-range configuration (at different counting rates) as well as an application to ΔE-E charged particle identification are shown. The presented discussion and results can be directly extended to various experimental arrangements.     

Hierarchical representation of motives in goal setting.

The authors developed a framework for thinking about motives in goal setting. The reasons for choosing a particular goal are represented in a hierarchical network of motives. To uncover context-specific motives and their interconnections, the authors propose a procedure based on the elicitation of justifications for one's goal. The authors applied the procedure to the motivation of volunteering to join the Italian Army by officers (N = 151) and 3 groups of enlisted soldiers (Garibaldi Brigade, N = 141; Folgore Brigade, N = 144; and volunteers in training, N = 150). The resulting idiographic motives and linkages between motives were validated by regressing attitudes, intentions to reenlist, and commitment toward the army on motives and linkages between motives. A heuristic nomothetic summary of goals, arranged in an interconnected hierarchy, was derived. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Molecular Landscape of Primary Acral Melanoma: A Multicenter Study of the Italian Melanoma Intergroup (IMI)

Acral melanoma (AM) is a rare and aggressive subtype of melanoma affecting the palms, soles, and nail apparatus with similar incidence among different ethnicities. AM is unrelated to ultraviolet radiation and has a low mutation burden but frequent chromosomal rearrangements and gene amplifications. Next generation sequencing of 33 genes and somatic copy number variation (CNV) analysis with genome-wide single nucleotide polymorphism arrays were performed in order to molecularly characterize 48 primary AMs of Italian patients in association with clinicopathological and prognostic features. BRAF was the most commonly mutated gene, followed by NRAS and TP53, whereas TERT promoter, KIT, and ARID1A were less frequently mutated. Gains and losses were recurrently found in the 1q, 6p, 7, 8q, 20 and 22 chromosomes involving PREX2, RAC1, KMT2C, BRAF, CCND1, TERT, and AKT3 genes, and in the 6q, 9, 10, 11q and 16q chromosomes including CDKN2A, PTEN, and ADAMTS18 genes, respectively. This study confirmed the variety of gene mutations and the high load of CNV in primary AM. Some genomic alterations were associated with histologic prognostic features. BRAF mutations, found with a higher rate than previously reported, correlated with a low Breslow thickness, low mitotic count, low CNV of the AMs, and with early-stage of disease.