Newness,Tradition and Identity: Existential Content and Meaning in Architecture

At a time when novelty and aesthetic invention have become the established norm for contemporary architecture, the esteemed Finnish author and architect Juhani Pallasmaa speaks out in defence of tradition. He explains how nuance, expressive subtlety and an ambition for an experiential and existential quality in a work require a sense of historical continuum: ‘An embodiment of the essence of tradition’ as a precursor for ‘meaningful creativity’.     

Temperature optimisation of a diesel engine using exhaust gas heat recovery and thermal energy storage (diesel engine with thermal energy storage)

Modern automotive diesel engines are so energy efficient that they are heating up slowly and tend to run rather cold at subzero temperatures. The problem is especially severe in mail delivery operations where the average speed is low and the drive cycle includes plenty of idling. The problem is typically solved by adding a diesel fuelled additional engine heater which is used for the preheating of the engine during cold start and additional heating of the engine if the coolant temperature falls below a thermostat set point during the drive cycle. However, this additional heater may drastically increase the total fuel consumption and exhaust gas emissions of the vehicle. In this study the additional heater was replaced by a combination of exhaust gas heat recovery system and latent heat accumulator for thermal energy storage. The system was evaluated on a laboratory dynamometer using a simulated drive cycle and in field testing in the city of Oulu (65°N), Finland in February 2009.     

Rheology and enhancement of extrusion of linear and branched polyethylenes using low amount of organoclay

Interaction between 0.05 wt % organoclay and polyethylenes of different short chain branching (SCB) was studied. Linear rheology (van Gurp‐Palmen plot) was used to study the effect of organoclay on the rheology of polyethylenes. Organoclay had effect only on the van Gurp‐Palmen plot of linear polyethylene. Fourier transform (FT) rheology, extrusion at high‐shear rates in a slit rheometer, transient stress growth analysis, and extensional rheology were conducted to examine the potential of organoclay as a processing aid. Organoclay reduced the transient stress overshoot, normal stress difference, ηo, onset of shear thinning, and extrusion pressure of polyethylene. The reduction was more pronounced in linear polyethylene without branching. Such effects gradually decreased as the branch content increased. The trend was independent of the type of flow (shear or extensional). It was interesting to note that FT rheology was not effective in explaining the impact of organoclay on polyethylene. The work concluded with the proposition that organoclay (as low as 0.05 wt %) was a good processing aid for linear polyethylene and polyethylenes with low content of SCB. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

The Ehrenfeucht conjecture: a compactness claim for finitely generated free monoids

We survey recent results on the so-called Ehrenfeucht Conjecture which states: For each language L over a finite alphabet Σ there exists a finite subset F of L such that for each pair (g, h) of morphisms on Σ¹ the equation g(x)=h(x) holds for all x in L if and only if holds for all x in F.We point out that the conjecture is closely related to the theory of equations in free monoids. We also state a suprising consequence of the conjecture: If it holds (even noneffectively) for all DOL languages, then the HDOL sequence equivalence problem is decidable. Furthermore, we give examples of when the conjecture is known to hold. In particular, we establish it for all binary languages, as well as for all languages when attention is restricted to bounded delay morphisms of some fixed delay.     

Inverse morphic equivalence on languages

We introduce the notion of inverse morphic equivalence of two morphisms g and h on a language L. Two variants are considered, the universal version, that is h^-1(x)=g^-1(x), for all x in L, and the existential version, that is h^-1(x)∩g^-1(x)≠Ø, for all x in L with h^-1(x)∪g^-1(x)≠Ø.     

Chemical inhibition of PCDD/F formation in incineration processes

This review summarises results of our pilot-scale experiments to find suitable inhibitors for preventing the formation of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) during waste incineration and to specify the role of the main factors affecting the inhibition process, and is based on doctoral dissertation of Ruokoja?rvi (2002). Results of previous experiments reported by other researchers are also presented and compared with ours. The detailed aims of our experiments were (1) to compare the effects of different inhibitors on PCDD/F formation during incineration in a pilot plant, (2) to investigate the role of the particle size distribution of the flue gas on the inhibition of PCDD/Fs, and (3) to find the main parameters affecting PCDD/F inhibition in waste incineration. Prevention of the formation of PCDD/Fs with chemical inhibitors and the effects of different supply points, feed temperatures and process parameters were studied in a pilot scale incinerator (50 kW) using light heating oil and refuse-derived fuel as test fuels. Various concentrations of the gaseous inhibitors (sulfur dioxide, ammonia, dimethylamine and methyl mercaptan) were sprayed into the flue gases after the furnace, in addition to which urea was dissolved in water and injected in at different concentrations. The residence time of the flue gas between the furnace and the PCDD/F sampling point was varied in the tests. In another set of urea tests, urea-water solutions at three concentrations were mixed with the RDF prior to incineration. PCDD/F and chlorophenol concentrations, together with other flue gas parameters (e.g. temperature, O2, CO, CO2 and NO), were analysed in the cooling flue gases. The gaseous and liquid inhibitors both notably reduced PCDD/F concentrations in the flue gas, the reductions achieved with the gaseous inhibitors varying from 50 to 78%, with dimethyl amine the most effective, while that produced with urea was up to 90%. The PCDD/F reductions were greater at increased inhibitor concentrations and with increased residence time of the flue gas between the furnace and the sampling point. PCDD/F concentrations in the particle phase decreased much more markedly than those in the gas phase. The urea inhibitor did not alter the particle size distribution of the PCDD/Fs when the amount of inhibitor was adequate. Chemical inhibitors seem to offer a very promising technique for preventing the formation of PCDD/Fs in waste incineration. The addition of urea to the fuel before combustion proved to be very effective approach and could be a useful technique even in the full-scale incinerators.     

HDTOL matching of computations of multitape automata

Summary We discuss the technique for testing the equivalence of two deterministic automata by constructing a language that matches the computations of two equivalent automata on the same input word. Specifically, we propose to use HDTOL languages that are powerful enough to match computations of many equivalent deterministic multitape automata, and at the same time, have nice decidable properties. Using this new technique of HDTOL matching, we show that the inclusion problem between an arbitrary deterministic multitape automaton and a simple one is decidable in both directions. Further, we show that the equivalence for a restricted class of transducers based on deterministic multitape automata is decidable.Reported research was supported by the National Sciences Foundation under Grant No. CCR-8702752 and by the Natural Sciences and Engineering Research Council of Canada under Grant No. A-7403     

Synchronizable deterministic pushdown automata and the decidability of their equivalence

Summary The notion of synchronized and synchronizable deterministic pushdown automata (DPDA's) is introduced. It is shown that the equivalence of two synchronized and even of synchronizable DPDA's can be tested. It is conjectured that every two equivalent DPDA's are synchronizable. It is also shown that the equivalence of two deterministic pushdown transducers whose underlying DPDA's are synchronized can be tested.This work was supported by the Natural Sciences and Engineering Research Council of Canada under Grant A-7403.This work has been done during the second author's visit at the University of Waterloo     

‘I want to know where my child is at all times’ – field study of a location-aware safety service for schoolchildren

This paper reports the findings of a long-term field study of the location-aware safety service for schoolchildren comprising a unique set-up of four service components from different service providers. End-users were closely involved as active and equally valued contributors in the participatory co-design study. The objective was to create a solution that would be suitable for common use by all end-user groups. As a result, a wearable safety gadget service was developed to answer the need to secure the independent mobility of primary schoolchildren via continuous and real-time monitoring of children’s movements when out of the home. User experiences were investigated through a variety of complementary data collection methods. Children were the most pleased user group, even though the service seemed to serve primarily their parents and teachers, the most distinctive value arising from the feeling of reassurance. Study findings direct future development efforts towards a personal alerting system that would become more integrated into everyday life. Our research provides valuable insights regarding the monitoring of a child on a situational basis, helping to derive design implications for developing a children’s safety solution that truly aligns with the values, needs, and practices of all stakeholders.