Fire Alarm Signal Recognition

The 1995 National Building Code of Canada requires that fire alarm signals sound the Temporal-Three (T-3) pattern, as defined by the ISO 8201 i2Acoustics ? Audible Emergency Evacuation Signalli. This sound pattern has also been required by NFPA 72 since July 1996. It is intended that the T-3 pattern will become the standardized alarm signal heard around the world that will unequivocally mean ieevacuate the building immediatelyly. Although new and refurbished buildings have, for the past 5 years, been equipped with this new signal, no formal public education has taken place to inform building users about the meaning and response expected from them when it sounds. In North America, discussions are ongoing regarding thenecessity to develop a public education campaign on the subject of this new evacuation signal, and whether an automatic recorded message should follow the signal to prompt the public to evacuate. As a first step, we need to ascertain if the public already recognizes this sound as an evacuation signal.Le Code national du b\ue2timent du Canada 1995 exige que les signaux \ue9mis par les alarmes d?incendie retentissent selon le mode de signalisation Temporal-3 (T-3), soit \ue0 trois (3) pulsations, comme d\ue9fini par la norme ISO 8201, \uab Acoustique ? signal sonore d?\ue9vacuation d?urgence \ubb. Le mode T-3 est \ue9galement requis depuis juillet 1996 par la norme NFPA 72. Ce mode pourrait devenir le signal d'alarme standard utilis\ue9 dans le monde entier pour signifier, sans \ue9quivoque, d?\ue9vacuer l'\ue9difice imm\ue9diatement. Bien que les \ue9difices construits ou r\ue9nov\ue9s depuis 5 ans aient tous \ue9t\ue9 \ue9quip\ue9s de ce syst\ue8me utilisant ce nouveau signal, nulle forme d?\ue9ducation officielle du public n?a jusqu?ici \ue9t\ue9 mise en place afin d?informer les usagers des b\ue2timents quant \ue0 la signification de ce signal et \ue0 la r\ue9ponse attendue de leur part lorsqu?il retentit. En Am\ue9rique du Nord, on d\ue9bat actuellement de la n\ue9cessit\ue9 de mettre sur pied une campagne d?\ue9ducation du grand public portant sur ce nouveau signal d?\ue9vacuation, et de la pertinence de le faire suivre ou non d?un message enregistr\ue9 automatique sollicitant l?\ue9vacuation des lieux. Or, comme premi\ue8re \ue9tape, il nous est n\ue9cessaire de d\ue9terminer si le public reconna\ueet d\ue9j\ue0 ce timbre comme signal d?\ue9vacuation.Peer reviewed: NoNRC publication: Ye

Influence of Particle Size and Crystal Orientation on theElectrochemical Behavior of Carbon-Coated LifePO4

We investigate the influence of particle size and crystal orientation on the electrochemical behavior of carboncoated LiFePO4 prepared by a hydrothermal synthesis in the presence of a polymeric surfactant and a source of carbon. We evaluated the charge/discharge profiles of two samples, one constituted by particles in the micrometer range with a platelet-like shape (large ac facet and (020) crystal orientation) and another made of sub-micrometer-rounded particles with a random crystal orientation. At low current rates the crystal orientation seems to be the prevailing factor, whereas at high current rates smaller particles can allow a shorter electronic conduction path, so reducing the resistance experienced by Li ions during diffusion

Experimental study of the influence of friction at the supports on longitudinal shear resistance of composite slabs

Abstract The aim of this work is to evaluate the behavior and strength of composite slabs considering the influence of the friction at the sheeting-concrete interface in the region of the support. Results from tests conducted in the Structural Engineering Department of Federal University of Minas Gerais (UFMG) were used. A Steel Deck 60 system was considered, which consists of a trapezoidal profile with “V” shaped embossments. Deflections, end slips and strains of the steel decks were measured, allowing for the analysis of the behavior of the composite slab system and for the determination of its failure mode. The influence of friction of the region of support in the longitudinal shear resistance was evaluated through the partial shear connection method, which also allowed for establishing criteria and determination of analytical expressions for calculating the ultimate load. Comparative analyses reveal that the influence of the friction of the region of support in the shear-bond resistance is more significant in composite slabs with short shear spans. Design expressions which incorporate friction will also be presented. Their application have demonstrated the efficiency of the method for evaluating the longitudinal shear resistance

Experimental study of the influence of friction at the supports on longitudinal shear resistance of composite slabs

<div><p>Abstract The aim of this work is to evaluate the behavior and strength of composite slabs considering the influence of the friction at the sheeting-concrete interface in the region of the support. Results from tests conducted in the Structural Engineering Department of Federal University of Minas Gerais (UFMG) were used. A Steel Deck 60 system was considered, which consists of a trapezoidal profile with “V” shaped embossments. Deflections, end slips and strains of the steel decks were measured, allowing for the analysis of the behavior of the composite slab system and for the determination of its failure mode. The influence of friction of the region of support in the longitudinal shear resistance was evaluated through the partial shear connection method, which also allowed for establishing criteria and determination of analytical expressions for calculating the ultimate load. Comparative analyses reveal that the influence of the friction of the region of support in the shear-bond resistance is more significant in composite slabs with short shear spans. Design expressions which incorporate friction will also be presented. Their application have demonstrated the efficiency of the method for evaluating the longitudinal shear resistance.</p></div

Biliquid Supercapacitors: a Simple and New Strategy to Enhance Energy Density in Asymmetric/Hybrid Devices

A novel strategy for the development of high energy density supercapacitors (SC) is explored. The new devices contain two electrolytes that are different in nature, an aqueous electrolyte in one half-cell and an ionic liquid in the other. These systems, referred to as biliquid SCs, make it possible to combine the best electrode/electrolyte in terms of individual electrode capacitance and cathodic/anodic stability limits. Furthermore, other asymmetries that combine different electrodes, electrolytes and storage mechanisms can be incorporated. Synchronous cyclic chronopotenciometry was used to monitor the performance of these novel complex systems. It is expected that this approach will help scientists working in this field to develop new devices that overcome the energy density limitations of current SCs, thereby extending the scope of their application.The authors would like to thank the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) − Brazil for the financial support (PVE 2014, process number 400714/2014-0). Paulo Fernando R. Ortega also acknowledges CNPq for the received scholarships. Financial support from Ministerio de Economía, Industria y Competitividad (project MAT2016-77114-R) and Principado de Asturias (Fondo Europeo de Desarrollo Regional, GRUPIN 14-118).Peer reviewe

MCM-41 silica effect on gel polymer electrolytes based on thermoplastic polyurethane

Polymer electrolytes were prepared from thermoplastic polyurethane with addition of mixture of Nethyl( methylether)-N-methylpyrrolidinium trifluoromethanesulfonimide (PYRA12O1TFSI) ionic liquid, lithium bis(trifluoromethanesulfoneimide) salt and propylene carbonate. MCM-41 mesoporous silica was added in proportions ranging from 5 to 20 wt.% with respect to TPU. The electrolytes were characterized by thermogravimetric analysis, differential scanning calorimetry, linear voltammetry and impedance spectroscopy. The MCM-41 addition to the system was found to improve the electrochemical stability of the membranes and to reduce the gel electrolyte/metallic Li interfacial resistance. The filler influence on the ion transport processes was discussed according to results obtained by equivalent circuit fitting of impedance spectra