Application of identification techniques to determine effect of carbon content in steels on rheological parameters during hot deformation

The objective of the present work is searching for the correlation between the carbon content in steels and the parameters of the rheological models, which are used to describe the materials behavior during hot plastic deformation. This correlation can be expected in the internal variable models, which are based on physical phenomena occurring in the material. Such a model, based on the dislocation density as the internal variable, is investigated in this work. The experiments including hot torsion tests are used for the analysis.
The procedure is composed of three parts. Plastometric tests were performed for steels with various carbon content. Optimization techniques were applied next to determine the coefficients in the internal variable rheological model for these steels. Two versions of the model are considered. One is based on the average dislocation density and the second accounts for the distribution of dislocation densities. Evaluation of correlation between carbon content and such coefficients in the models as activation energy for self diffusion, activation energy for recrystallization, grain boundary mobility, recovery coefficient etc. was the main objective of the work. In consequence, the model which may be used for simulation of hot forming processes for steels with various chemical compositions, is proposed.

Comparison of the EN 15251 and Ashrae Standard 55 adaptive thermal comfort models in the context of a Mediterranean climate

Strong heat waves in the past decade and resulting legal cases which gave full responsibility for indoor thermal comfort to building professionals lead to an increased uncertainty how to maintain thermal comfort in offices without the use of a cooling system. Adaptive thermal comfort standards such as EN 15251 and Ashrae Standard 55 provide methodologies to evaluate comfort in naturally ventilated spaces. Based on a parametric study for a typical cellular office in the context of Athens, Greece, and using the building simulation software EnergyPlus, this study investigates the potentials for the applicability of natural ventilation in a Mediterranean climate. The Ashrae Standard 55 and EN 15251 adaptive thermal comfort models are compared in this context, and conclusions are drawn how the use of natural ventilation based on adaptive models can be further encourgaged.

Strategies for improving the thermal performance and comfort levels of a kindergarten in the mountains of Nepal

Located on the Annapurna trekking trail in Nepal, Siurung is a remote mountain village where outside influences are almost non-existent. The thermal comfort levels of a recently-constructed kindergarten are well below international standards because of the climate and poor building envelope. A TRNSYS model of the kindergarten has been used to predict the current occupant comfort levels and subsequently determine the most effective way to alter the traditional construction methods to improve comfort levels. Improvements investigated were: reduced air infiltration, roof and wall insulation (separately and together), installation of a smokeless stove and a combination of all strategies.The model predicted that in the current building the PMV ranges from -1.94 in October to - 0.99 in July. It also predicted that the current PPD (%) ranges from 100 in January to 26 in July. With the combination of strategies, the predicted PMV values were all improved to between -1.08 and +0.34, and the PPD values of all months except January were reduced to below 10%. When improving the comfort levels of an existing school, reducing air infiltration, adding roof insulation and installing a smokeless stove are the most effective strategies. When constructing a new school, however, reducing air infiltration and adding insulation to the walls and roof are the most effective and feasible strategies. If a smokeless stove can be afforded and transported to the site, it is recommended that one be installed as it provides a more significant improvement than any other single strategy.

Conservation, duplication and divergence of the zebrafish stat5 genes

There are seven mammalian signal transducer and activator of transcription (Stat) proteins that act downstream of cytokine and growth factor receptors to mediate rapid changes in gene expression. The mammalian Stat5a and Stat5b genes show high sequence identity and lie adjacent in a head-to-head configuration next to the Stat3 gene, apparently the result of a relatively recent mammal-specific gene duplication event. We have identified and characterized two stat5 homologues that are expressed in zebrafish, named stat5.1 and stat5.2. The stat5.1 gene shows a high level of conservation with the single stat5 gene found in other teleosts and lies next to the stat3 gene, in the same relative orientation as the mammalian Stat5b gene. In contrast, the stat5.2 gene lies on a different chromosome to stat5.1 and stat3, and has diverged from the stat5 genes of other teleosts, with no apparent orthologue. Together, these data suggest that the ancestral Stat5 gene has undergone two independent gene duplication events to generate a stat5.2 paralogue in zebrafish and a Stat5a paralogue in mammals.

CH2 - lighting and physiology

This paper explains the designed performances of the new CH2 building in Melbourne, Australia. CH2 is an environmentally significant project that involves biomimicry of natural systems to produce indoor conditions that are conducive to user comfort, health and productivity. This paper focuses on lighting and  physiology and examines the solutions chosen for artificial and natural lighting and the likely effects these will have on building occupants. The purpose of the paper is to critically comment on the adopted strategy and, cognisance of  contemporary thinking in lighting design, to judge the effectiveness of this aspect of the project with a view to later verification and post-occupancy review. The  paper concludes that CH2 is an exemplar of lighting innovation that provides valuable lessons to designers of office buildings, particularly in the Melbourne CBD.

Regulation of metabolic transcriptional co-activators and transcription factors with acute exercise

Endurance exercise improves insulin sensitivity and increases fat oxidation, which are partly facilitated by the induction of metabolic transcription factors. Next to exercise, increased levels of FFA's also increase the gene expression of transcription factors, hence making it difficult to discern the effects from contractile signals produced during exercise, from those produced by increased circulatory FFA's. We aimed to investigate, in human skeletal muscle, whether acute exercise affects gene expression of metabolic transcriptional co-activators and transcription factors, including PGC-1α, PRC, PPARα, β/δ, and γ and RXR, SREBP-1c and FKHR, and to discern the effect of exercise per se from those of elevated levels of FFA. Two hours of endurance exercise was performed either in the fasted state, or following carbohydrate ingestion prior to and during exercise, thereby blunting the fasting-induced increase in FA availability and oxidation. Of the genes measured, PGC-1α and PRC mRNA increased immediately after, while PPARβ/δ and FKHR mRNA increased 1–4 h after exercise, irrespective of the increases in FFA's. Our results suggest that the induction in vivo of metabolic transcription factors implicated in mitochondrial biogenesis are under the control of inherent signals, (PGC-1α, PRC), while those implicated in substrate selection are under the control of associated signals (PPARβ/δ, FKHR) stimulated from the contracting skeletal muscle that are independent of circulating FFA levels.

High performance low-energy buildings

The era of legislation and creditable methods towards producing sustainable buildings is upon us. Yet, a major barrier to achieving environmental responsive design is in the lack of available information at the programming or pre-design phases of a project. The review and evaluation of climate as well as energy-efficient strategies could be difficult to consider at these preliminary stages. Until recently, introducing energy simulation tools at the design stage has been difficult and perhaps next to impossible at a pre-design or programming stage. However, analysis of this sort is essential to ‘green building rating’ or performance assessment schemes such as LEED (Leadership in Energy and Environmental Design) and BREEAM (Building Research Establishment Environment Assessment Method). This paper discusses the implementation of a particular tool, ENERGY-10, where ‘basecase’ building defaults are compared to a low-energy case which has applied multiple energy-efficient strategies automatically. An annual hour-by-hour simulation provides a daylighting calculation with a subsequent thermal evaluation. Calculation results provide energy consumption, peak load equipment sizing, a RANK feature of the energy-efficient strategies, reporting of CO2, SO2 and NOx reduction, optimum glazing type as well as excellent graphic output. Consideration is given as to the approach of how such information can be introduced into the building project brief enforcing a low-energy
performance target.

Between traditions : the villa and the country house

Sir Leslie Martin wrote in 1983, “The formal composition used by Lutyens is something totally related to the problems and culture of his time”. to reinforce this point Martin included a plan of Heathcote (1905) next to an illustration of one of Palladio’s final commissions, the Villa Rotonda (1566). Comparing the planning and symmetry strategies of the two architects, Martin was able to demonstrate how Heathcote embodied an eclectic yet fundamental link between two traditions - the irregularity of an Edwardian planning arrangement, and its containment within the symmetry demanded by the “full classical orchestra of a Doric order” (Hussey, 1950 p128). “Once inside the balanced mass of the exterior, the visitor’s movement through the building is controlled by volumes and composition of a totally different kind” 1. While Palladio appears to have been a significant influence on Lutyens, as revealed in the often quoted letter about the “High Game” which he wrote to Herbert Baker in 1903, few studies appear to explore the extent to which his newfound inspiration went beyond the issue of fenestration in affecting other aspects of his work. The following paper analyses Lutyens’s relationship to Palladio with particular reference to three concepts fundamental to the work of
both architects: proportion, plan arrangement and movement.

Changes in the Australian Commonwealth departmental machinery of government 1928-1982

The Commonwealth departmental machinery of government is changed by using Orders in Council to create, abolish or change the name of departments. Since 1906 governments have utilised a particular form of Order in Council, the Administrative Arrangements Order (AAO), as the means to reallocate functions between departments for administration. After 1928 successive governments from Scullin to Fraser gradually streamlined and increasingly used the formal processes for the executive to change departmental arrangements and the practical role of Parliament, in the process of change, virtually disappeared. From 1929 to 1982, 105 separate departments were brought into being, as new departments or through merger, and 91 were abolished, following the merger of their functions in one way or another with other departments. These figures exclude 6 situations where the change was simply that of name alone. Several hundred less substantial transfers of responsibilities were also made between departments. This dissertation describes, documents and analyses all these changes. The above changes can be distilled down to 79 events termed primary decisions. Measures of the magnitude of change arising from the decisions are developed with 157.25 units of change identified as occurring during the period, most being in the Whitlam and Fraser periods. The reasons for the changes were assessed and classified as occurring for reasons of policy, administrative logic or cabinet comfort. 47.2% of the units of change were attributed to policy, 34.9% to administrative logic, 17% to cabinet comfort. Further conclusions are drawn from more detailed analysis of the change and the reasons for the changes.

Molecular organization and viscosity of a thin film of molten polymer between two surfaces as probed by force measurements

Measurements are presented of the force between two molecularly smooth mica surfaces immersed in liquid poly(dimethylsiloxane) (Dow Corning 200 of nominal viscosity 50 cS) over a range of film thicknesses from 3 to 200 nm. There is a repulsion, attributed to conformational restrictions, when the polymer molecules are confined to a gap less than about 15 nm thick. In extremely thin films (<5 nm) the force is an oscillatory function of thickness with a repeat spacing corresponding to the width of the polymer molecule, which suggests that the polymer segments are arranged in layers near the solid surfaces. Dynamic force measurements show that the polymer has a viscosity equal to its bulk value even in very thin films, but a region next to each surface, only about one radius of gyration thick, does not flow. Saturation of the polymer with water destabilizes the film when it is very thin.

Occupant interaction with interior environment in Greek dwellings during summer

User behaviour significantly affects energy consumption simulation estimates, which can consequently influence architectural design decisions at an early stage. Different regional behavioural patterns could, therefore, hinder the applicability of certain architectural and environmental strategies. Through questionnaires analysis and field studies, this study investigates the pattern use of manual control of windows, shading and air condition units, in residential buildings in Greece, during summer. Initial findings of the analysis indicate significant interaction of Greek residents with the building shell, in their effort to maintain comfort.

Influence of turbulence on bed load sediment transport

This paper summarizes the results of an experimental study on the influence of an external turbulence field on the bed load sediment transport in an open channel. The external turbulence was generated by (1) a horizontal pipe placed halfway through the depth h; (2) a series of grids with a clearance of about one-third of the depth from the bed, and extending over a finite length of the flume; and (3) a series of grids with a clearance in the range (0.1−1.0)h from the bed, but extending over the entire length of the flume. Two kinds of experiments were conducted: plane-bed experiments and ripple-covered-bed experiments. In the former case, the flow in the presence of the turbulence generator was adjusted so that the mean bed shear stress was the same as in the case without the turbulence generator in order to single out the effect of the external turbulence on the sediment transport. In the ripple-covered-bed case, the mean and turbulence quantities of the streamwise component of the velocity were measured, and the Shields parameter, due to skin friction, was determined. The Shields parameter, together with the RMS value of the streamwise velocity fluctuations, was correlated with the sediment transport rate. The sediment transport increases markedly with increasing turbulence level.

Beware fast tracking high rise building

Currently, employers tend to fast rack works where construction can begin while design is still incomplete following three main phases of procurement. This session details a case study of a fast track overseas super high rise building, where an Australian firm acted as a technical expert to provide a detailed report on the failure of the shoring system, while construction of five basements had just started next to a marina. The lessons learnt from the case study are summarized with recommendations to have better practice of the fast track method in complex high rise buildings.

Age, class and race discrimination: their interactions and associations with mental health among Brazilian university students

Although research on discrimination and health has progressed significantly, it has tended to focus on racial discrimination and US populations. This study explored different types of discrimination, their interactions and associations with common mental disorders among Brazilian university students, in Rio de Janeiro in 2010. Associations between discrimination and common mental disorders were examined using multiple logistic regression models, adjusted for confounders. Interactions between discrimination and socio-demographics were tested. Discrimination attributed to age, class and skin color/race were the most frequently reported. In a fully adjusted model, discrimination attributed to skin color/race and class were both independently associated with increased odds of common mental disorders. The simultaneous reporting of skin color/race, class and age discrimination was associated with the highest odds ratio. No significant interactions were found. Skin color/race and class discrimination were important, but their simultaneous reporting, in conjunction with age discrimination, were associated with the highest occurrence of common mental disorders.

Atmospheric quality and distribution of heavy metals in Argentina employing Tillandsia capillaris as a biomonitor.

The atmospheric quality and distribution of heavy metals were evaluated throughout a wide region of Argentina. In addition, the biomonitor performance of Tillandsia capillaris Ruiz & Pav. f. capillaris was studied in relation to the accumulation of heavy metals and to its physiologic response to air pollutants. A sampling area of 50,000 km2 was selected in the central region of the Argentine Republic. This area was subdivided into grids of 25 x 25 km. Pools of T. capillaris, where present, were collected at each intersection point. From each pool three sub-samples were analyzed independently. Furthermore, five replicates were collected at 20% of the points in order to analyze the variability within the site. The content of Co, Cu, Fe, Ni, Mn, Pb and Zn was determined by Atomic Absorption Spectrometry. Chemical-physiological parameters were also determined to detect symptoms of foliar damage. Chlorophylls, phaeophytins, hydroperoxy conjugated dienes, malondialdehyde and sulfur were quantified in T. capillaris. Some of these parameters were used to calculate a foliar damage index. Data sets were evaluated by one-way ANOVA, correlation analysis, principal component analysis and mapping. Geographical distribution patterns were obtained for the different metals reflecting the contribution of natural and anthropogenic emission sources. According to our results it can be inferred that Fe, Mn and Co probably originated in the soil. For Pb, the highest values were found in the mountainous area, which can be attributed to the presence of Pb in the granitic rocks. Ni showed mainly an anthropogenic origin, with higher values found in places next to industrial centers. For Zn the highest values were in areas of agricultural development. The same was observed for Cu, whose presence could be related to the employment of pesticides. The foliar damage index distribution map showed that the central and southeastern zones were the ones where the major damage in the bioindicator was found. The central zone coincides with the city of Córdoba whereas the southeastern area is strictly agricultural, so the high values found there could be related to the use of pesticides.