Demonstrating Improved Fuel Economy Using Subsystem Specific Lubricants on a Modified Diesel Engine

Fuel economy performance in modern internal combustion engines is of increasing importance to lubricant formulators due to regulations targeting global greenhouse gas emissions. Engines typically employ a single lubricant, with a common sump, to service all components. As a result, base oil and additive selection for fuel economy performance is a compromise among competing demands for different engine subsystems. Opportunities for significant fuel economy improvement through targeted formulation of lubricants for specific engine subsystems are presented, with specific emphasis on segregating the lubricant supplies for the valve train and the power cylinder subsystems. A working prototype was developed in a lab environment by modifying a commercially available twin-cylinder diesel engine. Motored valve train and whole-engine fired test results were obtained and compared to model data. Fuel economy benefits were demonstrated using market representative heavy-duty diesel lubricants, including mineral oil and polyalphaolefin (PAO) blends. The fuel economy benefits of a dual-loop lubricant system are demonstrated through significant viscosity reduction in the power cylinder subsystem, achieving overall engine friction reductions of up to 8% for the investigated operating condition. Results suggest that additional gains may be realized through targeted base oil and additive formulation. Implications for incorporation in larger diesel engines are also considered.     

Fatigue life estimation of cast components

An engineering method based on fracture mechanics is suggested for life predictions of components of nodular cast iron. The method should be applicable to any structure containing defects which can cause crack initiation. Component testing was performed and the observed results were compared with model predictions. Fatigue crack growth data were obtained by testing on CT specimens even for load ratios R < 0. By accounting for crack closure the R-effect on the growth rates can also be effectively eliminated for this type of material.     

Ca2+ Signalling Induced by NGF Identifies a Subset of Capsaicin-Excitable Neurons Displaying Enhanced Chemo-Nociception in Dorsal Root Ganglion Explants from Adult pirt-GCaMP3 Mouse

Nociceptors sense hazards via plasmalemmal cation channels, including transient receptor potential vanilloid 1 (TRPV1). Nerve growth factor (NGF) sensitises TRPV1 to capsaicin (CAPS), modulates nociceptor excitability and induces thermal hyperalgesia, but cellular mechanisms remain unclear. Confocal microscopy was used to image changes in intracellular Ca²⁺ concentration ([Ca²⁺]_i) across neuronal populations in dorsal root ganglia (DRG) explants from pirt-GCaMP3 adult mice, which express a fluorescent reporter in their sensory neurons. Raised [Ca²⁺]_i was detected in 84 neurons of three DRG explants exposed to NGF (100 ng/mL) and most (96%) of these were also excited by 1 μM CAPS. NGF elevated [Ca²⁺]_i in about one-third of the neurons stimulated by 1 μM CAPS, whether applied before or after the latter. In neurons excitable by NGF, CAPS-evoked [Ca²⁺]_i signals appeared significantly sooner (e.g., respective lags of 1.0 ± 0.1 and 1.9 ± 0.1 min), were much (>30%) brighter and lasted longer (6.6 ± 0.4 vs. 3.9 ± 0.2 min) relative to those non-responsive to the neurotrophin. CAPS tachyphylaxis lowered signal intensity by ~60% but was largely prevented by NGF. Increasing CAPS from 1 to 10 μM nearly doubled the number of cells activated but only modestly increased the amount co-activated by NGF. In conclusion, a sub-population of the CAPS-sensitive neurons in adult mouse DRG that can be excited by NGF is more sensitive to CAPS, responds with stronger signals and is further sensitised by transient exposure to the neurotrophin.     

What makes virtual agents believable?

In this paper we investigate the concept of believability and make an attempt to isolate individual characteristics (features) that contribute to making virtual characters believable. As the result of this investigation we have produced a formalisation of believability and based on this formalisation built a computational framework focused on simulation of believable virtual agents that possess the identified features. In order to test whether the identified features are, in fact, responsible for agents being perceived as more believable, we have conducted a user study. In this study we tested user reactions towards the virtual characters that were created for a simulation of aboriginal inhabitants of a particular area of Sydney, Australia in 1770 A.D. The participants of our user study were exposed to short simulated scenes, in which virtual agents performed some behaviour in two different ways (while possessing a certain aspect of believability vs. not possessing it). The results of the study indicate that virtual agents that appear resource bounded, are aware of their environment, own interaction capabilities and their state in the world, agents that can adapt to changes in the environment and exist in correct social context are those that are being perceived as more believable. Further in the paper we discuss these and other believability features and provide a quantitative analysis of the level of contribution for each such feature to the overall perceived believability of a virtual agent.     

Evaluating Pore Space in Macroporous Ceramics with Water‐Based Porosimetry

We show that water‐based porosimetry (WBP), a facile, simple, and nondestructive porosimetry technique, accurately evaluates both the pore size distribution and throat size distribution of sacrificially templated macroporous alumina. The pore size distribution and throat size distribution derived from the WBP evaluation in uptake (imbibition) and release (drainage) mode, respectively, were corroborated by mercury porosimetry and X‐ray micro‐computed tomography (μ‐CT). In contrast with mercury porosimetry, the WBP also provided information on the presence of “dead‐end pores” in the macroporous alumina.     

Shear effect in beta‐phase induction of polypropylene in a single screw extruder

In this work, we investigated the effect of four different configurations at the exit of a single‐screw extruder on the induction of beta phase in PP for four different rotational speeds. The configuration of a breaker plate with 120 orifices of 1‐mm diameter and 7‐mm length each, give the highest content of beta‐phase (56.92%), for a screw rotational speed of 20 rpm. It was due to the shear caused separation of the melt when it passes through the orifices of the breaker plate. The breaker plate of configuration 4 (breaker plate with the greatest number of orifices) provided the largest number of contacts between the melt and the orifice walls resulting in chain alignment. The results show that the beta‐phase can be induced in the polymer without any further additives, especially without any nucleating agents, but rather by using a special breaker plate configuration at the exit of the single‐screw extruder. The skin‐core structure of the polymer was only developed with one type of extruder configuration. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2932–2937, 2013     

The Influence of Platinum Addition on Nano-Crystalline Ceria Catalysts for the Total Oxidation of Naphthalene a Model Polycyclic Aromatic Hydrocarbon

Abstract  

The effect of adding Pt to a highly active ceria polycyclic aromatic hydrocarbon total oxidation catalyst has been investigated for the oxidation of naphthalene. The addition of Pt to ceria suppressed the performance of the catalyst for total oxidation. The addition of Pt reduced catalyst surface area, decreased the ceria crystallite size, decreased the concentration of ceria defects and increased the reducibility of the catalyst. The suppression of activity has been attributed to strong metal-support interaction between Pt and ceria, which limits the availability of lattice oxygen for the oxidation process, which follows the Mars-Van Krevelen redox mechanism in the absence of Pt. It is postulated that the presence of dispersed Pt, alters the mechanism of naphthalene oxidation over the ceria catalyst.     

The influence of temperature and cyclic loading on adhesion in polycarbonate-polyurethane-glass adhesive joint

The paper deals with the influence of temperature and cyclic loading on adhesion and transparency of the adhesive joint consisting of soda-lime-silica glass and polycarbonate (PC) bonded with polyurethane (PU) adhesive film. The tested joint represents critical part of transparent armored glass used in vehicles. Dynamic tension creep tests were performed at temperatures to which armored glass is commonly exposed (25, 50, 60, 70, and 80?°C). Sawtooth loading mode was performed to 650?N and the sine loading in the force range 0–1550?N. The aim of the paper was to discover conditions causing delamination of the adhesive joint and glass milky appearance during the use. Delamination of soda-lime-silica glass/PU adhesive interface occurred at 25?°C after load to 1550?N without the change of transparency. Both dynamic and static tension creep tests performed to 400?N led to plastic deformation of PU adhesive at and above 70?°C, in preference at both ends and circumference edges of adhesive joint, and thus, to loss of transparency, but extent of deformation differed. Milky maps observed after sawtooth load to 650?N at 80?°C reflected delaminated areas of highly deformed PU adhesive. Temperature of 70?°C was found out to be the critical parameter being in synergy effect with different thermal expansion of PC and PU adhesive.     

Omega-3 PUFA of marine origin limit diet-induced obesity in mice by reducing cellularity of adipose tissue

Omega-3 PUFA of marine origin reduce adiposity in animals fed a high-fat diet. Our aim was to learn whether EPA and DHA could limit development of obesity and reduce cellularity of adipose tissue and whether other dietary FA could influence the effect of EPA/DHA. Weight gain induced by composite high-fat diet in C57BL/6J mice was limited when the content of EPA/DHA was increased from 1 to 12% (wt/wt) of dietary lipids. Accumulation of adipose tissue was reduced, especially of the epididymal fat. Low ratio of EPA to DHA promoted the effect. A higher dose of EPA/DHA was required to reduce adiposity when admixed to diets that did not promote obesity, the semisynthetic high-fat diets rich in EFA, either α-linolenic acid (ALA, 18∶3 n−3, the precursor of EPA and DHA) or linoleic (18∶2 n−6) acid. Quantification of adipose tissue DNA revealed that except for the diet rich in ALA the reduction of epididymal fat was associated with 34–50% depression of tissue cellularity, similar to the 30% caloric restriction in the case of the high-fat composite diet. Changes in plasma markers and adipose gene expression indicated improvement of lipid and glucose metabolism due to EPA/DHA even in the context of the diet rich in ALA. Our results document augmentation of the antiadipogenic effect of EPA/DHA during development of obesity and suggest that EPA/DHA could reduce accumulation of body fat by limiting both hypertrophy and hyperplasia of fat cells. Increased dietary intake of EPA/DHA may be beneficial regardless of the ALA intake.