Preparation and characterization of multi-walled carbon nanotubes supported PtRu catalysts for proton exchange membrane fuel cells

A series of PtRu nanocomposites supported on H2O2-oxidized multi-walled carbon nanotubes (MWCNTs) were synthesized via two chemical reduction methods - one used aqueous formaldehyde (HCHO method) and the other used ethylene glycol (EG method) as the reducing agents. The effects of the solvents (water and ethylene glycol) and the surface composition of the MWCNTs on the deposition and the dispersion of the metal particles were investigated using N-2 adsorption. TEM. ICP-AES. FTIR and TPD. The wetting heats of the MWCNTs in corresponding solvents were also measured. The characterizations suggest that combination of the surface chemistry of the MWCNTs with the solvents decides the deposition and the dispersion of the metal nanoparticles. These nanocomposites were evaluated as proton exchange membrane fuel cell anode catalyts for oxidation of 50 ppm CO contaminated hydrogen and compared with a commercial PtRu/C catalyst. The data reveal superior performances for the nanocomposites prepared by the EG method to those by the HCHO method and even to that for tile Commercial analogue. Structure performance relationship of the nanocomposites was also studied. (C) 2005 Elsevier Ltd. All rights reserved.

Methane dehydroaromatization over Mo/HZSM-5 catalysts: The reactivity of MoCx species formed from MoOx associated and non-associated with Bronsted acid sites

The catalytic performances of methane dehydroaromatization (MDA) under non-oxidative conditions over 6 wt.% Mo/HZSM-5 catalysts calcined for different durations of time at 773 K have been investigated in combination with ex situ H-1 MAS NMR characterization. Prolongation of the calcination time at 773 K is in favor of the diffusion of the Mo species on the external surface and the migration of Mo species into the channels, resulting in a further decrease in the number of Bronsted acid sites, while causing only a slight change in the Mo contents of the bulk and in the framework structure of the HZSM-5 zeolite. The MoQ(x) species associated and non-associated with the Bronsted acid sites can be estimated quantitatively based on the 1H MAS NMR measurements as well as on the assumption of a stoichiometry ratio of 1: 1 between the Mo species and the Bronsted acid sites. Calcining the 6 wt.% Mo/HZSM-5 catalyst at 773 K for 18 h can cause the MoOx species to associate with the Bronsted acid sites, while a 6 Wt-% MO/SiO2 sample can be taken as a catalyst in which all MoOx species are non-associated with the Bronsted acid sites. The TOF data at different times on stream on the 6 wt.% Mo/HZSM-5 catalyst calcined at 773 K for 18 h and on the 6 Wt-% MO/SiO2 catalyst reveal that the MoCx species formed from MoOx associated with the Bronsted acid sites are more active and stable than those formed from MoOx non-associated with the Bronsted acid sites. An analysis of the TPO profiles recorded on the used 6 wt.% Mo/HZSM-5 catalysts calcined for different durations of time combined with the TGA measurements also reveals that the more of the MoCx species formed from MoOx species associated with the Br6nsted acid sites, the lower the amount of coke that will be deposited on it. The decrease of the coke amount is mainly due to a decrease in the coke burnt-off at high temperature. (c) 2005 Elsevier B.V. All rights reserved.

Synthesis and catalytic reactivity of MCM-22/ZSM-35 composites for olefin aromatization

A series of MCM-22/ZSM-35 composites has been hydrothermally synthesized and characterized by XRD, SEM, particle size distribution analysis, N-2 adsorption and NH3-TPD techniques. Pulse and continuous flow reactions were carried out to evaluate the catalytic performances of these composites in aromatization of olefins, respectively. It was found that MCM-22/ZSM-35 composites could be rapidly crystallized at 174 degrees C with an optimal gel composition of SiO2/Al2O3=25, Na2O/SiO2=0.11, HMI/SiO2=0.35, and H2O/SiO2=45 (molar ratio), of which the weight ratio of ZSM-35 zeolite in the composite relied on the crystallization time. The coexistence of MCM-22 and ZSM-35 in the composite (MCM-22/ZSM-35=45/55 wt/wt) was observed to exert a notable synergistic effect on the aromatization ability for butene conversion and FCC gasoline updating, possibly due to the intergrowth of some MCM-22 and ZSM-35 layers.

Liquid phase oxidation of toluene to benzaldehyde with molecular oxygen over copper-based heterogeneous catalysts

We conducted the liquid phase oxidation of toluene with molecular oxygen over heterogeneous catalysts of copper-based binary metal oxides. Among the copper-based binary metal oxides, iron-copper binary oxide (Fe/Cu = 0.3 atomic ratio) was found to be the best catalyst. In the presence of pyridine, overoxidation of benzaldehyde to benzoic acid was partially prevented. As a result, highly selective formation of benzaldehyde (86% selectivity) was observed after 2 h of reaction (7% conversion of toluene) at 463 K and 1.0 MPa of oxygen atmosphere in the presence of pyridine. These catalytic performances were similar or better than those in the gas phase oxidation of toluene at reaction temperatures higher than 473 K and under 0.5-2.5 MPa. It was suggested from competitive adsorption measurements that pyridine could reduce the adsorption of benzaldehyde. At a long reaction time of 4 It, the conversion increased to 25% and benzoic acid became the predominant reaction product (72% selectivity) in the absence of pyridine. The yield of benzoic acid was higher than that in the Snia-Viscosa process, which requires corrosive halogen ions and acidic solvents in the homogeneous reaction media. The catalyst was easily recycled by simple filtration and reusable after washing and drying.

Investigation of LSM1.1-ScSZ composite cathodes for anode-supported solid oxide fuel cells

La0.8Sr0.2Mn1.1O3 (LSM1.1)-10 mol% Sc2O3-Stabilized ZrO2 co-doped with CeO2 (ScSZ) composite cathodes were investigated for anode-supported solid oxide fuel cells (SOFCs) with thin 8 mol% Y2O3-stabilized ZrO2 (YSZ) electrolyte. X-ray diffraction (XRD) results indicated that the ScSZ electrolytes displayed good chemical compatibility with the nonstoichiometric LSM1.1 against co-firing at 1300 degrees C. Increasing the CeO2 content in the ScSZ electrolytes dramatically suppressed the electrode polarization resistance, which may be related to the improved surface oxygen exchange or the enlarged active area of cathode. The 5Ce10ScZr was the best electrolyte for the composite cathodes, which caused a small ohmic resistance decrease and the reduced polarization resistance and brought about the highest cell performance. The cell performances at lower temperatures seemed to rely on the electrode polarization resistance more seriously, than the ohmic resistance. Compared with the cell impedance at higher temperatures, the higher the 5Ce10ScZr proportion in the composite cathodes, the smaller the increment of the charge transfer resistance at lower temperatures. The anode-supported SOFC with the LSM1.1-5Ce10ScZr (60:40) composite cathode achieved the maximum power densities of 0.82 W/cm(2) at 650 degrees C and 2.24 W/cm(2) at 800 degrees C, respectively. (c) 2005 Elsevier B.V. All rights reserved.

NY10128

This work for chamber orchestra explores the relationship between music and architecture, specifically that of the Guggenheim Museum, NYC. It was commissioned by the Edinburgh Contemporary Music Ensemble who gave the first performance in June 2008. Subsequent performances in 2011 by the National Youth Orchestra of Scotland have been accompanied by a film I created exploring the surfaces and profiles of the Guggenheim NYC.

Agency and animation: the performance of interactive game characters

As an animator and practice-based researcher with a background in games development, I am interested in technological change in the video game medium, with a focus on the tools and technologies that drive game character animation and interactive story. In particular, I am concerned with the issue of ‘user agency’, or the ability of the end user to affect story development—a key quality of the gaming experience and essential to the aesthetics of gaming, which is defined in large measure by its interactive elements. In this paper I consider the unique qualities of the video game1 as an artistic medium and the impact that these qualities have on the production of animated virtual character performances. I discuss the somewhat oppositional nature of animated character performances found in games from recent years, which range from inactive to active—in other words, low to high agency. Where procedural techniques (based on coded rules of movement) are used to model dynamic character performances, the user has the ability to interactively affect characters in real-time within the larger sphere of the game. This game play creates a high degree of user agency. However, it lacks the aesthetic nuances of the more crafted sections of games: the short cut-scenes, or narrative interludes where entire acted performances are mapped onto game characters (often via performance capture)2 and constructed into relatively cinematic representations. While visually spectacular, cut-scenes involve minimal interactivity, so user agency is low. Contemporary games typically float between these two distinct methods of animation, from a focus on user agency and dynamically responsive animation to a focus on animated character performance in sections where the user is a passive participant. We tend to think of the majority of action in games as taking place via playable figures: an avatar or central character that represents a player. However, there is another realm of characters that also partake in actions ranging from significant to incidental: non-playable characters, or NPCs, which populate action sequences where game play takes place as well as cut scenes that unfold without much or any interaction on the part of the player. NPCs are the equivalent to supporting roles, bit characters, or extras in the world of cinema. Minor NPCs may simply be background characters or enemies to defeat, but many NPCs are crucial to the overall game story. It is my argument that, thus far, no game has successfully utilized the full potential of these characters to contribute toward development of interactive, high performance action. In particular, a type of NPC that I have identified as ‘pivotal’3—those constituting the supporting cast of a video game—are essential to the telling of a game story, particularly in genres that focus on story and characters: adventure games, action games, and role-playing games. A game story can be defined as the entirety of the narrative, told through non-interactive cut-scenes as well a interactive sections of play, and development of more complex stories in games clearly impacts the animation of NPCs. I argue that NPCs in games must be capable of acting with emotion throughout a game—in the cutscenes, which are tightly controlled, but also in sections of game play, where player agency can potentially alter the story in real-time. When the animated performance of NPCs and user agency are not continuous throughout the game, the implication is that game stories may be primarily told through short movies within games, making it more difficult to define video games animation as a distinct artistic medium.

In Comes I: Performance, Memory and Landscape

Pearson, Mike, In Comes I: Performance, Memory and Landscape (Exeter: University of Exeter Press, 2007) RAE2008

The game jam movement: disruption, performance and artwork

This paper explores the current conventions and intentions of the game jam - contemporary events that encourage the rapid, collaborative creation of game design prototypes. Game jams are often renowned for their capacity to encourage creativity and the development of alternative, innovative game designs. However, there is a growing necessity for game jams to continue to challenge traditional development practices through evolving new formats and perspectives to maintain the game jam as a disruptive, refreshing aspect of game development culture. As in other creative jam style events, a game jam is not only a process but also, an outcome. Through a discussion of the literature this paper establishes a theoretical basis with which to analyse game jams as disruptive, performative processes that result in original creative artefacts. In support of this, case study analysis of Development Cultures: a series of workshops that centred on innovation and new forms of practice through play, chance, and experimentation, is presented. The findings indicate that game jams can be considered as processes that inspire creativity within a community and that the resulting performances can be considered as a form of creative artefact, thus parallels can be drawn between game jams and performative and interactive art.

Ansiedade e percepções/atitudes dos profissionais da educação face à avaliação de desempenho

Dissertação de Mestrado apresentada à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Psicologia, especialização em Psicologia da Educação e Intervenção Comunitária.

Antropologia e psicoterapia

Tese apresentada à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Doutor em Ciências Sociais, especialidade em Antropologia

Contributo para o desenvolvimento de um Instrumento de Investigação Neuropsicológica

Tese apresentada à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Doutor em Ciências Sociais, especialidade em Psicologia

Nanostructured materials for Lithium-ion battery technology

The Li-ion battery has for several years been at the forefront of powering an ever-increasing number of modem consumer electronic devices such as laptops, tablet PCs, cell phones, portable music players etc., while in more recent times, has also been sought to power a range of emerging electric and hybrid-electric vehicle classes. Given their extreme popularity, a number of features which define the performance of the Li-ion battery have become a target of improvement and have garnered tremendous research effort over the past two decades. Features such as battery capacity, voltage, lifetime, rate performance, together with important implications such as safety, environmental benignity and cost have all attracted attention. Although properties such as cell voltage and theoretical capacity are bound by the selection of electrode materials which constitute its interior, other performance makers of the Li-ion battery such as actual capacity, lifetime and rate performance may be improved by tailoring such materials with characteristics favourable to Li+ intercalation. One such tailoring route involves shrinking of the constituent electrode materials to that of the nanoscale, where the ultra-small diameters may bestow favourable Li+ intercalation properties while providing a necessary mechanical robustness during routine electrochemical operation. The work detailed in this thesis describes a range of synthetic routes taken in nanostructuring a selection of choice Li-ion positive electrode candidates, together with a review of their respective Li-ion performances. Chapter one of this thesis serves to highlight a number of key advancements which have been made and detailed in the literature over recent years pertaining to the use of nanostructured materials in Li-ion technology. Chapter two provides an overview of the experimental conditions and techniques employed in the synthesis and electrochemical characterisation of the as-prepared electrode materials constituting this doctoral thesis. Chapter three details the synthesis of small-diameter V2O5 and V2O5/TiO2 nanocomposite structures prepared by a novel carbon nanocage templating method using liquid precursors. Chapter four details a hydrothermal synthesis and characterisation of nanostructured β-LiVOPO4 powders together with an overview of their Li+ insertion properties while chapter five focuses on supercritical fluid synthesis as one technique in the tailoring of FeF2 and CoF2 powders having potentially appealing Li-ion 'conversion' properties. Finally, chapter six summarises the overall conclusions drawn from the results presented in this thesis, coupled with an indication of potential future work which may be explored upon the materials described in this work.

A knowledge management system to optimise comfort throughout the building life-cycle

Comfort is, in essence, satisfaction with the environment, and with respect to the indoor environment it is primarily satisfaction with the thermal conditions and air quality. Improving comfort has social, health and economic benefits, and is more financially significant than any other building cost. Despite this, comfort is not strictly managed throughout the building lifecycle. This is mainly due to the lack of an appropriate system to adequately manage comfort knowledge through the construction process into operation. Previous proposals to improve knowledge management have not been successfully adopted by the construction industry. To address this, the BabySteps approach was devised. BabySteps is an approach, proposed by this research, which states that for an innovation to be adopted into the industry it must be implementable through a number of small changes. This research proposes that improving the management of comfort knowledge will improve comfort. ComMet is a new methodology proposed by this research that manages comfort knowledge. It enables comfort knowledge to be captured, stored and accessed throughout the building life-cycle and so allowing it to be re-used in future stages of the building project and in future projects. It does this using the following: Comfort Performances – These are simplified numerical representations of the comfort of the indoor environment. Comfort Performances quantify the comfort at each stage of the building life-cycle using standard comfort metrics. Comfort Ratings - These are a means of classifying the comfort conditions of the indoor environment according to an appropriate standard. Comfort Ratings are generated by comparing different Comfort Performances. Comfort Ratings provide additional information relating to the comfort conditions of the indoor environment, which is not readily determined from the individual Comfort Performances. Comfort History – This is a continuous descriptive record of the comfort throughout the project, with a focus on documenting the items and activities, proposed and implemented, which could potentially affect comfort. Each aspect of the Comfort History is linked to the relevant comfort entity it references. These three components create a comprehensive record of the comfort throughout the building lifecycle. They are then stored and made available in a common format in a central location which allows them to be re-used ad infinitum. The LCMS System was developed to implement the ComMet methodology. It uses current and emerging technologies to capture, store and allow easy access to comfort knowledge as specified by ComMet. LCMS is an IT system that is a combination of the following six components: Building Standards; Modelling & Simulation; Physical Measurement through the specially developed Egg-Whisk (Wireless Sensor) Network; Data Manipulation; Information Recording; Knowledge Storage and Access.Results from a test case application of the LCMS system - an existing office room at a research facility - highlighted that while some aspects of comfort were being maintained, the building’s environment was not in compliance with the acceptable levels as stipulated by the relevant building standards. The implementation of ComMet, through LCMS, demonstrates how comfort, typically only considered during early design, can be measured and managed appropriately through systematic application of the methodology as means of ensuring a healthy internal environment in the building.

Investigation of polyhydroxyalkanoate production by an activated sludge microbial consortium treating artificial dairy wastewater

Petrochemical plastics/polymers are a common feature of day to day living as they occur in packaging, furniture, mobile phones, computers, construction equipment etc. However, these materials are produced from non-renewable materials and are resistant to microbial degradation in the environment. Considerable research has therefore been carried out into the production of sustainable, biodegradable polymers, amenable to microbial catabolism to CO2 and H2O. A key group of microbial polyesters, widely considered as optimal replacement polymers, are the Polyhydroxyalkaonates (PHAs). Primary research in this area has focused on using recombinant pure cultures to optimise PHA yields, however, despite considerable success, the high costs of pure culture fermentation have thus far hindered the commercial viability of PHAs thus produced. In more recent years work has begun to focus on mixed cultures for the optimisation of PHA production, with waste incorporations offering optimal production cost reductions. The scale of dairy processing in Ireland, and the high organic load wastewaters generated, represent an excellent potential substrate for bioconversion to PHAs in a mixed culture system. The current study sought to investigate the potential for such bioconversion in a laboratory scale biological system and to establish key operational and microbial characteristics of same. Two sequencing batch reactors were set up and operated along the lines of an enhanced biological phosphate removal (EBPR) system, which has PHA accumulation as a key step within repeated rounds of anaerobic/aerobic cycling. Influents to the reactors varied only in the carbon sources provided. Reactor 1 received artificial wastewater with acetate alone, which is known to be readily converted to PHA in the anaerobic step of EBPR. Reactor 2 wastewater influent contained acetate and skim milk to imitate a dairy processing effluent. Chemical monitoring of nutrient remediation within the reactors as continuously applied and EBPR consistent performances observed. Qualitative analysis of the sludge was carried out using fluorescence microscopy with Nile Blue A lipophillic stain and PHA production was confirmed in both reactors. Quantitative analysis via HPLC detection of crotonic acid derivatives revealed the fluorescence to be short chain length Polyhydroxybutyrate, with biomass dry weight accumulations of 11% and 13% being observed in reactors 1 and 2, respectively. Gas Chromatography-Mass Spectrometry for medium chain length methyl ester derivatives revealed the presence of hydroxyoctanoic, -decanoic and -dodecanoic acids in reactor 1. Similar analyses in reactor 2 revealed monomers of 3-hydroxydodecenoic and 3-hydroxytetradecanoic acids. Investigation of the microbial ecology of both reactors as conducted in an attempt to identify key species potentially contributing to reactor performance. Culture dependent investigations indicated that quite different communities were present in both reactors. Reactor 1 isolates demonstrated the following species distributions Pseudomonas (82%), Delftia acidovorans (3%), Acinetobacter sp. (5%) Aminobacter sp., (3%) Bacillus sp. (3%), Thauera sp., (3%) and Cytophaga sp. (3%). Relative species distributions among reactor 2 profiled isolates were more evenly distributed between Pseudoxanthomonas (32%), Thauera sp (24%), Acinetobacter (24%), Citrobacter sp (8%), Lactococcus lactis (5%), Lysinibacillus (5%) and Elizabethkingia (2%). In both reactors Gammaproteobacteria dominated the cultured isolates. Culture independent 16S rRNA gene analyses revealed differing profiles for both reactors. Reactor 1 clone distribution was as follows; Zooglea resiniphila (83%), Zooglea oryzae (2%), Pedobacter composti (5%), Neissericeae sp. (2%) Rhodobacter sp. (2%), Runella defluvii (3%) and Streptococcus sp. (3%). RFLP based species distribution among the reactor 2 clones was as follows; Runella defluvii (50%), Zoogloea oryzae (20%), Flavobacterium sp. (9%), Simplicispira sp. (6%), Uncultured Sphingobacteria sp. (6%), Arcicella (6%) and Leadbetterella bysophila (3%). Betaproteobacteria dominated the 16S rRNA gene clones identified in both reactors. FISH analysis with Nile Blue dual staining resolved these divergent findings, identifying the Betaproteobacteria as dominant PHA accumulators within the reactor sludges, although species/strain specific allocations could not be made. GC analysis of the sludge had indicated the presence of both medium chain length as well short chain length PHAs accumulating in both reactors. In addition the cultured isolates from the reactors had been identified previously as mcl and scl PHA producers, respectively. Characterisations of the PHA monomer profiles of the individual isolates were therefore performed to screen for potential novel scl-mcl PHAs. Nitrogen limitation driven PHA accumulation in E2 minimal media revealed a greater propensity among isoates for mcl-pHA production. HPLC analysis indicated that PHB production was not a major feature of the reactor isolates and this was supported by the low presence of scl phaC1 genes among PCR screened isolates. A high percentage distribution of phaC2 mcl-PHA synthase genes was recorded, with the majority sharing high percentage homology with class II synthases from Pseudomonas sp. The common presence of a phaC2 homologue was not reflected in the production of a common polymer. Considerable variation was noted in both the monomer composition and ratios following GC analysis. While co-polymer production could not be demonstrated, potentially novel synthase substrate specificities were noted which could be exploited further in the future.