Maneuvering Area, Corridors and Lobbies for Wheeled Mobility Aid users

World is evolving rapidly, and new accessibility equipment and devices are being introduced which makes life easier for the people with disabilities. However, the rapid developments in the evolution of accessibility equipment may not always be coordinated with the existing accessibility norms and standards. The gap between accessibility provisions in built environments and developments in accessibility equipment is increasing by not taking the evolution of assistive equipment into account. By having a future orientated view on the development of accessibility equipment, some of the existing accessibility norms and provisions may thus require to change significantly. One of the important assistive mobility device types is Wheeled Mobility Device (WMD) or Wheeled Mobility Aid (WMA) that considered most effective way of improving the impact of mobility limitations for many people with mobility impairments. The design of wheeled mobility aids is rapidly evolving, and therefore the relevant accessibility standards for built environments need reconsideration respectively to cover future developments. The evolution in wheeled mobility device have meanings in different parts of the built environment such as building facilities, access to the building, entrance to the building, parking spaces and etc. The main goal of this study is to investigate and find new proposals for norms/standards related to Maneuvering Area, Corridors and Lobbies for Wheeled Mobility Aid users based on the evolution in mobility aids

HOMOGENEOUS CATALYSIS AND MASS TRANSFER IN BIPHASIC IONIC LIQUID SYSTEMS WITH COMPRESSED CO2 AND ORGANIC COMPOUNDS

ABSTRACT Homogeneous catalysis in which the catalyst, solvents and reactants are all in the same phase can yield high activity and selectivity and efficiently produce chemical products. However, the main problem with these kinds of reactions is separating and reusing precious metal catalyst; therefore, it needs to be performed in a convenient platform. To figure out this problem, a biphasic system can be suggested in which one phase sequesters the solid catalyst and the other phase delivers reactants to and remove products from the reaction media. But, there are some problems using these methods such as thermodynamics and solubility issues, mass transfer limitations, cross-contamination problems, environmental concerns and possibility for a continuous process. Thus, a biphasic ionic liquid (IL) /CO2 system is suggested, which may solve these problems. In this research, special properties of ionic liquids that can make them be the next class of alternative solvents is introduced, and subsequently the main issues in using them is discussed. Then, to overcome the abovementioned problems, a combined biphasic ionic liquid / CO2 system is managed to be used for homogeneous catalytic reactions. The main purpose of this project is running homogeneous catalytic reactions in biphasic IL/CO2 media and managing key parameters in kinetics, momentum and mass transfer, and phase behavior to control the reaction in an efficient zone. For this reason, two typical and large homogeneous catalytic reactions that are practiced in industry, hydroformylation and hydrogenation of 1-octene, have been selected. In order to investigate the effect of CO2 pressure on controlling the reaction over the mass transfer or kinetic zones, thorough studies have been arranged to determine the phase behavior and thermodynamic properties of compounds (reactants, products, and solvents) within the reaction conditions. It has also been revealed in this work that the momentum and mass transfer parameters (diffusivity and viscosity) of ionic liquids can be managed by either the structure of ionic liquids or the pressure of various compressed gases. Thus, the measured and correlated results of viscosities and diffusivities for pure and saturated of different types of ionic liquids with compressed CO2 and 1,1,1,2-tetrafluoroethane (R134a) are reported for further studies to choose the best media (ionic liquid/compressed gas) for reactions. Due to significant impacts of mass transfer on the reaction because of the high viscosity of ionic liquids, it is quite necessary to find mass transfer parameters for the reaction in the biphasic IL/CO2 system. At the first step in these studies, the phase equilibrium, volumetric, and interfacial properties of the catalytic media (ionic liquid phase) and the main substrate (1-octene) have been determined. Then, using the obtained information, the mass transfer coefficient is calculated. Finally, based on these experimental results, a robust, realistic, and efficient finite element method has been developed by Petera - Weatherley to model mass transfer between an ionic liquid droplet and 1-octene continuous system. At the end, further studies are recommended to find mass transfer parameters under compressed CO2 pressure and in presence of gas reactants on the reaction condition to superior understanding and managing the reaction characteristics

High-pressure phase equilibria with compressed gases

This is the published version. Copyright 2007 American Institute of Physics.An apparatus is described that is capable of determining high-pressure vapor-liquid equilibrium, liquid-liquid equilibrium, solid-liquid-vapor equilibrium, vapor-liquid-liquid equilibrium, and mixture critical points and transitions. The device is capable of temperatures to 150°C and pressures to 300bars (higher with slight modifications). The construction and operation are described in detail and do not require the use of mercury. This method requires very low sample volumes and no analytical equipment nor system-specific calibration. The apparatus was verified by comparison with literature data for the decane-CO2 mixture and CO2-ionic liquid [1-hexyl-3-methyl-imidazolium bis(trifyl)imide)] systems. The experimental data have excellent agreement with the literature data that used different experimental methods. A rigorous error analysis of the system is also presented

Hydrophobic Gas-Diffusion Media for Polymer-Electrolyte Fuel Cells by Direct Fluorination

A polymer-electrolyte fuel cell depends on proper water management to obtain high performance. During operation, liquid water is generated in the cell. When it is not properly and adequately removed, accumulation leads to poor fuel-cell performance by reducing and blocking the gas pores in the catalyst and gas-diffusion media. To address this problem, gas-diffusion media are often coated with a wet-proofing agent. This approach results in reduced pore size and volume resulting in lower transport properties, as well as inducing durability and performance issues due to the inherent non-uniformity. To overcome these issues, an alternative wet-proofing process called direct fluorination was developed. In this approach, fluorine gas reacts with carbon to create a more uniform, durable, and consistent wet-proof surface without affecting the morphology of the media. The fluorinated media showed capillary pressure properties that are more suitable for fuel-cell application. Fuel cells with fluorinated materials in the cathodes showed better performance, lower ohmic resistance, and lower liquid water amount in the cathode. These advantages are attributed to having a better wet-proofed fluorinated media at the cathode that forces water back to the anode, thereby keeping the membrane more hydrated and reducing the amount of water in and transported out of the cathode

Mathematical Representation of Viscosity of Ionic Liquid + Molecular Solvent Mixtures at Various Temperatures Using the Jouyban–Acree Model

Article on mathematical representation of viscosity of ionic liquid and molecular solvent mixtures at various temperatures using the Jouyban-Acree model