Detailed characterization of particulates emitted by pre-commercial single-cylinder gasoline compression ignition engine

Gasoline Compression Ignition (GCI) engines have the potential to achieve high fuel efficiency and to significantly reduce both NOx and particulate matter (PM) emissions by operating under dilute, partially-premixed conditions. This low temperature combustion strategy is dependent upon direct-injection of gasoline during the compression stroke and potentially near top dead center (TDC). The timing and duration of the in-cylinder injections can be tailored based on speed and load to create optimized conditions that result in a stable combustion.     

Life after Implementation: Managing System Maintenance

Although much is being done to improve new systems and to increase the productivity of development personnel, system maintenance—which accounts for more than 50 percent of software labor costs and up to 75 percent of system life—has received little attention. This article presents a unified management approach to software maintenance, viewing it in terms of overall system life, describing the steps in the maintenance process, and suggesting guidelines for maintenance personnel management.     

Analysis of creep in a welded ‘P91’ pressure vessel

The present work considers the uniaxial and multiaxial creep behaviour of the tempered martensite 9%Cr 1%Mo steel ‘P91’ and the creep behaviour of welds in a P91 pressure vessel. The microstructure of a base metal/weld metal transition in a thick section pipe was analysed by means of optical microscopy and hardness measurements. Special emphasis was given to three microstructural states: the base metal (BM), the weld metal (WM) and the intercritical heat affected zone material (IC-HAZ). A significant difference between these three microstructures was their subgrain size, which was measured in the transmission electron microscope and was found to be smallest for the weld metal and largest for the intercritical heat affected zone material. The uniaxial creep behaviour of the three material states was analysed and it was shown that the creep strength increased with decreasing subgrain size. The elastic modulus of P91 was measured and the uniaxial creep behaviour of the three material states was characterized and represented by (i) the Norton law and (ii) in terms of the Robinson model. A welded pressure vessel was creep tested and hoop and axial strains were measured for three welds in the vessel. A creep stress analysis of the welded pressure vessel was performed based on (i) Norton's law and (ii) the Robinson model concentrating on the accumulated hoop and axial strains in the welds. Measured and calculated axial and hoop strains were found to be in good agreement.     

Plant uptake of non ionic organic chemicals

Plant uptake of organic chemicals is an important process when considering the risks associated with land contamination, the role of vegetation in the global cycling of persistent organic pollutants, and the potential for industrial discharges to contaminate the food chain. There have been some significant advances in our understanding of the processes of plant uptake of organic chemicals in recent years; most notably there is now a better understanding of the air to plant transfer pathway, which may be significant for a number of industrial chemicals. This review identifies the key processes involved in the plant uptake of organic chemicals including those for which there is currently little information, e.g., plant lipid content and plant metabolism. One of the principal findings is that although a number of predictive models exist using established relationships, these require further validation if they are to be considered sufficiently robust for the purposes of contaminated land risk assessment or for prediction of the global cycling of persistent organic pollutants. Finally, a number of processes are identified which should be the focus of future research.     

Tele-immersive environments for rehabilitation activities: an empirical study on proprioception

Those with proprioceptive impairments can use their other senses as the proprioceptive feedback. We hypothesize that tele-immersion systems can aid in this supplemented proprioception by providing novel visual perspectives of one’s own body. In particular we are interested as to whether the real-time 3D reconstructions used in tele-immersive systems are better or worse than conventional 2D views (i.e. video) with regards to aiding a task requiring proprioception. The objective of this study is to investigate the stated hypothesis by quantifying and ranking the various visual and auditory cues available in a tele-immersive system as they are used during an assigned task. The paper briefly describes a portable immersive VR system, our methodology for quantifying task performance, and results from our experiments with wheelchair basketball athletes.     

Strongly code-disjoint CMOS built-in intermediate voltage sensor for totally self-checking circuits

In this paper, we describe a new approach to the design and the implementation of a strongly code-disjoint CMOS built-in intermediate voltage sensor (BIVS). The function of the BIVS is to detect any intermediate voltage caused by bridging faults in the functional circuit of a two-rail code totally self-checking system. It is shown that the proposed BIVS can detect and tolerate faults in itself. An application example employing the BIVS is used to show the effectiveness of the design.