Experimental study on the time‐dependent smoke densities at 39 locations in a multi‐floor building through a digital smoke detector system

The objective of this study was to quantitatively investigate some characteristics of the smoke transportation in multi‐floor buildings. Eight experiments were conducted for worst scenario. The effects of an open window in the burning room on the smoke transportation are also analyzed. The time‐dependent smoke densities at 39 locations in a half‐scale building with an atrium were measured through a digital smoke detector system. The results indicate that the chimney effect plays an important role in the smoke transportation in multi‐floor buildings with atriums. For the effects of the open window, the results suggest that the smoke densities at most locations in the building increase earlier when a window is open but have a smaller peak value than those results in the cases without any outer vents. It is suggested that a building without vertical atrium would be safer than those with long ones. More attention should be paid to those spaces when the fire protection systems are designed for buildings with atriums. The data of the time‐dependent smoke densities at tens of locations in the building are useful for the validation of smoke transportation models. Copyright © 2013 John Wiley & Sons, Ltd.     

1, 5-Bis (2-hydroxyacetophenone)thiocarbohydrazone: A novel colorimetric and fluorescent dual-mode chemosensor for the recognition of fluoride

1,5-Bis (2-hydroxyacetophenone)thiocarbohydrazone (H₄L) has been synthesized and characterized by means of spectroscopic and single crystal X-ray diffraction methods. Interactions of the H₄L with a variety of anions were investigated using a combination of UV–visible and fluorescence spectroscopic methods in a biological competing solvent DMSO. The H₄L has a high degree of selectivity for fluoride over other anions. ¹H NMR titration experiments indicate that a deprotonation process is involved in the chemo sensing process.     

Multiplex real-time PCR Method for the detection and quantification of DNA from the four transgenic soy traits DP-356043-5, DP-305423-1, MON 87701, and BPS-CV127-9 and lectin

According to the release of authorization, several new transgenic soy crops are expected to be present in the harvest of soy beans. In contrast to earlier times, methods for the detection of these transgenic crops are available already in advance. However, these methods are mainly still inefficient single real-time PCR methods. To increase the efficiency of product control, a multiplex quantitative real-time PCR system was developed and characterized for the four new transgenic soy traits DP-356043-5, DP-305423-1, MON 87701 and BPS-CV127-9. It showed amplification efficiency, correlation and sensitivity similar to the single PCR systems applied therein. To evaluate the robustness, an appropriate testing scheme was developed and applied for the first time on this multiplex real-time PCR system. It showed the robust amplification of all analytes also in case where conditions were varied. This system allows relative multiplex quantification and/or delta–delta Ct method quantification and proofed the applicability in routine.     

Performance optimization of polymer electrolyte membrane fuel cells using the Nelder-Mead algorithm

The direct-search simplex method for function optimization has been adapted to performance optimization of polymer electrolyte membrane fuel cells (PEMFCs). The established method is strongly application oriented and uses only experimentally determined data for optimization. It is not restricted to discrete parameters optimums and does not require the use of third-party software or computational resources. Hence, it is easy to implement in fuel cell testing stations. The optimization consists of finding, for a given fuel cell load, an optimum set of values of the 7 fuel cell operating parameters: the fuel cell temperature, the reactants' stoichiometric ratios, the reactants' inlet relative humidity, and the reactants' outlet pressures, resulting in the highest fuel cell performance. The performance is measured using a scalar function of the operating parameters and the load and can be defined according to needs.Two PEMFC performance functions: the fuel cell voltage and the system-related fuel cell efficiency were optimized using the procedure for practically sized PEMFC stacks of two designs. With respect to the nominal operating conditions defined as optimal for each stack design by its manufacturer, the gains from the optimization procedure were up to over 12% and up to over 7% for the stack voltage and efficiency, respectively. The validation of the procedure involved 5 stack specimens and four laboratories and consistent results were obtained.     

A mesh reconfiguration scheme for speeding up Monte Carlo simulations of electromagnetic scattering by random rough surfaces

Traditional methods of Monte Carlo simulations of random rough surface scattering that use the finite element method involve the generation of multiple meshes for the purpose of taking ensemble averages. We propose a mesh reconfiguration scheme that instead uses a single master mesh. The main idea is to locally modify only the air–surface interface region in the mesh for each instance of a random rough surface. This method achieves a four fold improvement in computation time without any loss of accuracy.     

Curing enhancement and network effects in multi‐walled carbon nanotube‐filled vulcanized natural rubber: evidence for solvent sensing

Electrically and thermally conductive polymer composites offer great possibilities in various electronic fields because of their low weight and ease of processing. This paper addresses the curing behaviour and network properties of conducting multi‐walled carbon nanotube (MWCNT)‐reinforced natural rubber (NR) nanocomposites, emphasizing the sensing and diffusion performances. NR/MWCNT composites were prepared following a special master batch technique which allows the appropriate distribution of nanotubes within the elastomer. The sensing responses of the composites towards solvents were observed as variations in electrical resistance. Thermal resistance and glass transition behaviour were examined and correlated with the swelling measurements as evidence for solvent sensing. An optimum level of 3 phr of MWCNTs is understood to lead to the best properties for the NR/MWCNT composites. Finally, the structural morphology and interfacial interactions were found to have correlations with cure reactions, glass transition temperatures and sensing responses of all compositions. © 2017 Society of Chemical Industry