Reduced‐scale test to assess the effect of fire barriers on the flaming combustion of cored composites: An upholstery‐material case study

Herein, we describe a reduced‐scale test (“Cube” test), measuring the fire performance of specimens including a fire barrier (FB) and a flammable core material, which acts as the main fuel load. The specimen is intended to reproduce a cross‐section of a composite product where heat/mass transfer occurs primarily in a direction perpendicular to the FB. The Cube test procedure and benefits are discussed in this work by adopting residential upholstery furniture as an exemplary study. One flexible polyurethane foam, one polypropylene cover fabric, and 10 commercially available FBs were selected. They were used to compare the fire performance of FBs, measured in terms of peak of heat release rate, in the ASTM E1474‐14 standard test and the newly developed Cube test. Edge effects severely affected the performance of FBs in the ASTM E1474‐14 standard test but not in the Cube test. Furthermore, appropriate test conditions were determined in the Cube test to measure the so‐called “wetting point,” that is, the time and value of heat release rate measured when flammable liquid products were first observed on the bottom of the specimen. The relevance of the “wetting point” in terms of full‐scale fire performance and failure mechanism of FBs is discussed.     

CHEMICAL ANALYSIS OF HIGH ASH BRAZILIAN COAL TAR. 3. HYDROCARBON CHARACTERIZATION

Abstract

In this paper we show the total analysis of the hydrocarbon fractions obtained from the chromatographic fractionation of a coal tar cut, previously described. All fractions were analyzed by Gas Chromatography coupled to Mass Spectrometry using a non-polar capillary column. A group-type distribution of aliphatic, olefins and monoaromatic hydrocarbons was found in the first three fractions obtained (I, II and III). In fractions IV and V polyaromatics with two or more condensed rings were founded. Many of these hydrocarbons are recognized to be carcinogenic and mutagenic, including pyrene, chrysene and others.     

Curvature Ratio Effect on Two-Phase Pressure Drops in Horizontal Return Bends: Experimental Data for R134a

This article presents 154 pressure drop data points measured during two-phase flow of R-134a in horizontal return bends. The tube diameter is constant at 10.85 mm and the curvature ratio is either 7.74 or 5.53. Saturation temperature varies from 15 to 20°C, vapor quality from 0.05 and 0.95, and mass velocity ranges from 300 to 600 kg m^?2 s^?1. Return bend pressure drops are calculated by subtracting the straight tube pressure drop from the total measured pressure drop along the bend. The perturbations induced up- and downstream of the singularity are taken into account in the measurements. The comparison of the pressure drops for the two configurations (curvature ratio of 5.53 and 7.74) showed that they are greater (about 10%) for the larger curvature ratio. This can be attributed to the effect of the developed length on the pressure drop; on the other side the pressure gradients are larger for the lower curvature ratio, which can be explained by the effect of the centrifugal force and the perturbations up- and downstream of the return bend. The experimental data are compared against four prediction methods available in the literature. The Domanski and Hermès correlation is the best at predicting the present data.     

A new model for the analysis of operating conditions of micro-cogenerative SOFC units

High Temperature Solid Oxide Fuel Cells (HT-SOFCs) represent a very promising technology for efficient energy conversion, and offer the possibility of distributed micro-cogeneration. Efficient modelling of actual SOFC operating conditions, after proper validation, is very important for the control and management of future commercial units, and very useful for the design of experiments in prototype systems, like the one considered in this work. The paper presents a new zero dimensional (0D) model for the simulation of a SOFCs based micro-cogenerative power system for residential use, fed by natural gas. The novelty of the proposed model consists in the ability to accurately reproduce the logic of the on-board control system. The model is validated against the data collected during an experimental campaign recently conducted by the authors on a field unit. The validated model is used to investigate the actual performance of the generator under different operating conditions, and to design new experiments. The results shown in this paper highlight the importance of the thermal control strategy on the actual performance of the cogenerative power system.     

用于地毯和纺织品的新纤维

在意大利Aquafil公司与特伦托大学合作进行的科研工作的基础上,介绍和讨论了用于地毯和纺织品的新纤维的新的试验方法.此外,指出了各种创新的多种聚合物复合所得的结果.结果证实,由反应纺丝得到的多种聚合物的复合纤维,力学性质具有单值性.     

Leakage Estimation in Water Distribution Network: Effect of the Shape and Size Cracks

Water Resources Management - The definition of the relationship between the leak outflow, the total head at the leak and other relevant parameters such as pipe stiffness, leak dimension and shape...     

Electrocatalysis of methanol,ethanol and formic acid using a Ru/Pt metallic bilayer

This work describes the methanol, ethanol and formic acid oxidation using a metallic bilayer electrodeposited on a platinum substrate. Firstly, one monolayer of ruthenium was deposited on the substrate and over it a 1.1 layer of metallic platinum. In the blank solution it was observed that the electrochemical behavior of both the Pt/Ru/Pt and bulk Pt were very similar, except in the oxygen evolution potential region. Using X-ray photoelectronic spectroscopy (XPS) it was not possible to identify the presence of Ru atoms on the bilayer surface. The electroactive area and the RMS roughness factor measured with atomic force microscopy (AFM) for both materials are the same. A CO monolayer oxidation procedure confirmed that the systems have the same real surface area and also showed a shift in the negative direction for 54 mV on the CO peak potential for the bilayer. For the voltammetric organic molecules oxidation, an enhancement in the current densities of 350, 390 and 420% was observed for ethanol, methanol and formic acid, respectively, for the bilayer system compared to the bulk Pt electrodes. Also, a decrease of 110 mV in the beginning of the ethanol oxidation process was observed over the bilayer system compared to bulk Pt.     

3D model of a sector of the South Scotia Ridge (Antarctica)

A three-dimensional geological model was built to show and analyse a northern sector of the Scotia–Antarctica transform plate boundary.The South Scotia Ridge is a 400 km long submerged continental structural high representing the eastern continuation of the Antarctic Peninsula. South Scotia Ridge runs approximately in the E–W direction, separating Scotia Sea Plate from Antarctica Plates. Structures, due to the transform plate margin, are considered to be concentrated inside this continental high. The three-dimensional model, built using seismic profiles and a digital elevation model, is a powerful tool to visualize and help to understand deep geological structures. Maps and profiles, on the contrary, only give a two-dimensional view, and do not show the structure of the continental–oceanic boundary at depth.The model shows that the deformation style of the continental–oceanic boundary, and of the oceanic crust nearby, is related to the left-lateral movement of the main transform fault system. Furthermore, it seems to be connected to the orientation and geometry of the South Scotia Ridge with respect to the homogeneous deformation regime, which affects the entire Scotia Plate. Moving from west to east, the NW-dipping main fault surface becomes almost vertical with a sinistral strike–slip movement in the central sector. To the east, a south-dipping plane decreases its inclination and changes orientation (from E–W to ESE–WNW): here shortening features are visible.The three-dimensional geological model presents a western and central province wherein the continental–oceanic boundary involves the fragmented continental blocks, the continental slope, the oceanic basement and sediments. The sedimentary cover and the oceanic basement are not deformed in the eastern province.     

An infrastructure to support cooperation of knowledge-level agents on the semantic Grid

Can a Knowledge-Level layer be located in the Semantic Grid infrastructure? Is it possible to design an Agent Communication Language (ACL) which enables Knowledge-Level agents to cooperate in a geographically distributed Semantic Grid despite nodes’ failures or malfunctions? This paper tries to address the above Semantic Grid challenges presenting an agent-based Open Service Architecture which integrates geographically distributed agents in a Semantic Grid. The architecture is well integrated with standard Internet components and technologies and supports communication among Knowledge-Level agents. The role of agents is to retrieve, execute and compose available services providing more sophisticated instances of them. Inter-agent communication is realized by exploiting an advanced Agent Communication Language which supports a fault-tolerant anonymous interaction protocol and satisfies a set of well defined Knowledge-Level programming requirements. Here, we present the design of the architecture and of the Agent Communication Language as well as their implementation. The architecture is evaluated by means of several case studies which highlight the main feature of our proposal. The main advantage of our approach is to demonstrate that different issues, such as high level inter-agent communication and fault tolerance, can be successfully integrated in Grid infrastructures which provide Web Services maintaining a clean design of the architecture and a Knowledge-Level characterization.