Performance characteristics of a miniaturised chemical looping steam reformer for hydrogen enrichment of fuels

A miniaturised chemical looping steam reformer (μ-CLSR) is being developed at the University of Newcastle (Australia) for onboard hydrogen enrichment of fuels in internal combustion engines. Experimental results from the first prototype highlighted an imbalance between the rates of redox reactions. A new configuration has been developed to resolve this shortcoming. The objective of this study is to examine the effectiveness of the new configuration in handling the imbalance between redox rates. Experiments were conducted on magnetite and wuestite metal oxides under methane and steam environments in the new configuration. Results indicate that if micro-reactors within the reformer are operated in parallel during the oxidation half cycle and in sequence during the reduction half cycle, the imbalance can be effectively managed. This combined with manifold switching of reacting gases at 48 s intervals enables metal oxides to achieve a 30% fractional conversion at 900 °C; resulting in a product gas stream with 96% H₂ purity.     

Effects of colloidal properties on sensible heat transfer in water-based titania nanofluids

Nanofluids have attracted considerable attention in recent years as effective working fluids in heat transfer applications. Nanofluids are essentially suspensions of nanoparticles in a base fluid and exhibit higher thermal conductivity than conventional heat transfer fluids.     

Numerical analysis of transport phenomena for designing of ejector in PEM forklift system

In the present study, Computational Fluid Dynamics (CFD) technique is used to design an ejector for anode recirculation in an automotive PEMFC system. A CFD model is firstly established and tested against well-documented and relevant solutions from the literature, and then used for different ejector geometries under different operating conditions. Results showed that a single ejector with optimized geometry cannot cover the required recirculation in the entire range of the fuel cell current. Having two ejectors for different ranges of currents is thus proposed as an alternative solution in which the system can better take the advantage of ejectors for recirculation purpose. In addition, the operating mode of one variable nozzle ejector has been investigated and compared with aforementioned cases. The results showed that the variable nozzle ejector can work in the same operational mode as in the case with two ejectors. However, in practice, the latter one needs a more complicated control system and it is more difficult to manufacture.     

Mechanical properties of composites from sawdust and recycled plastics

Mechanical properties of wood plastic composites (WPCs) manufactured from sawdust and virgin and/or recycled plastics, namely high density polyethylene (HDPE) and polypropylene (PP), were studied. Sawdust was prepared from beech industrial sawdust by screening to the desired particle size and was mixed with different virgin or recycled plastics at 50% by weight fiber loading. The mixed materials were then compression molded into panels. Flexural and tensile properties and impact strength of the manufactured WPCs were determined according to the relevant standard specifications. Although composites containing PP (virgin and recycled) exhibited higher stiffness and strength than those made from HDPE (virgin and recycled), they had lower unnotched impact strengths. Mechanical properties of specimens containing recycled plastics (HDPE and PP) were statistically similar and comparable to those of composites made from virgin plastics. This was considered as a possibility to expand the use of recycled plastics in the manufacture of WPCs. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3641–3645, 2006     

Shading and lighting operation in office buildings in Austria: A study of user control behavior

Occupants of buildings typically operate devices such as windows, shades, luminaires, radiators, and fans to bring about desirable indoor environmental conditions. These control actions can have a significant impact on buildings’ performance (energy use, indoor climate). A better understanding of control-oriented user behavior can not only facilitate more accurate predictions of buildings’ performance, but also support the effective operation of buildings’ service systems. This paper describes a study of control-oriented user behavior (as related to systems for lighting and shading) in three office buildings in Austria. The results specifically shed light on the relationships between control actions and environmental conditions inside and outside buildings.     

Combination of mechanical and informational modeling to predict hysteresis behavior of I beam‐to‐CFT column connection

The behavior of beam‐to‐column connections is significantly complicated because it depends on the material, nonlinear relationship between different members, and contact of connecting elements. Their hysteretic response exhibits highly inelastic characteristics and continuous variation in stiffness, strength, and ductility. Therefore, accurate hysteretic models of bolted connections are essential to accurate seismic assessment and design. Composed (Hybrid) modeling approach is presented to represent the complex hysteretic behavior of I beam‐to‐concrete‐filled‐tube (CFT) column bolted connection. For the purpose in this study, experimental evaluation of I beam‐to‐CFT column connection with bolted end‐plate under cyclic loading is done. It must be mentioned to make the connection easily applicable practically and also prepare the column flanges continuity, a connection with the bolts penetrated into the CFT column are used since using the stiffeners in hollow sections is not easily applicable. In the composed mechanical–informational modeling framework, the conventional mechanical model is complemented by information‐based model components. Finally, moment–rotation curves of composed model have been compared with experimental results. Comparison showed that the composed model has a good agreement with experimental results. A newly designed specimen for validation purpose of the composed modeling was made and experimented. Composed model was well applied to predict the behavior of new connections. The presented results show that the composed model has a good ability to predict of hysteretic behavior.     

Seismic Rehabilitation of Tall Steel Moment Resisting Frames Damaged by Fire with SMA-Based Hybrid Friction Damper

International Journal of Steel Structures - The existence probability of buildings, which have been under fire and not been collapsed for various reasons is not low, thus they are in dangerous...     

Cargo scheduling decision support for offshore oil and gas production: a case study

Woodside Energy Ltd (Woodside), Australia’s largest independent oil and gas company, operates multiple oil and gas facilities off the coast of Western Australia. These facilities require regular cargo shipments from supply vessels based in Karratha, Western Australia. In this paper, we describe a decision support model for scheduling the cargo shipments to minimize travel cost and trip duration, subject to various operational restrictions including vessel capacities, cargo demands at the facilities, time windows at the facilities, and base opening times. The model is a type of non-standard vehicle routing problem involving multiple supply vessels—a primary supply vessel that visits every facility during a round trip taking at most 1 week, and other supply vessels that are used on an ad hoc basis when the primary vessel cannot meet all cargo demands. We validate the model via test simulations using real data provided by Woodside.     

Oxygen adsorption and desorption characteristics of LSCF5582 membranes for oxygen separation applications

This study examines the oxygen adsorption and desorption characteristics of La_0.5Sr_0.5Co_0.8Fe_0.2O_3?δ (LSCF5582) membranes prepared at sintering temperatures of 1200–1300 °C, with the aim of gaining an insight into their performance in the surface reaction limited regime for oxygen separation applications. The findings of this work are then compared with our experimental data on Ba_0.5Sr_0.5Co_0.8Fe_0.2O_3?δ (BSCF5582) membranes. It is demonstrated that the adsorption rate constants of both membranes are two orders of magnitude greater than their respective oxygen desorption rate constants as the oxygen adsorption occurs in less than 24 s whilst the oxygen desorption takes approximately one hour to reach equilibrium. The activation energy for oxygen adsorption of LSCF5582 reduced to a quarter of its value with increasing the sintering temperature from 1200 °C to 1300 °C. This is attributed to the oxygen exchange occurring more rapidly along the grain boundaries resulting in a lower activation energy. The LSCF5582 grain sintered at 1200 °C is the optimum selection for oxygen separation applications at an operating temperature of 850 °C and oxygen partial pressure of 0.21 bar.