965 resultados para Mean nuclear volume


Relevância:

20.00% 20.00%

Publicador:

Resumo:

The current study explored the influence of moral values (measured by ethical ideology) on self-reported driving anger and aggressive driving responses. A convenience sample of drivers aged 17-73 years (n = 280) in Queensland, Australia, completed a self-report survey. Measures included sensation seeking, trait aggression, driving anger, endorsement of aggressive driving responses and ethical ideology (Ethical Position Questionnaire, EPQ). Scores on the two underlying dimensions of the EPQ idealism (highI/lowI) and relativism (highR/lowR) were used to categorise drivers into four ideological groups: Situationists (highI/highR); Absolutists (highI/lowR); Subjectivists (lowI/highR); and Exceptionists (lowI/lowR). Mean aggressive driving scores suggested that exceptionists were significantly more likely to endorse aggressive responses. After accounting for demographic variables, sensation seeking and driving anger, ethical ideological category added significantly, though modestly to the prediction of aggressive driving responses. Patterns in results suggest that those drivers in ideological groups characterised by greater concern to avoid affecting others negatively (i.e. highI, Situationists, Absolutists) may be less likely to endorse aggressive driving responses, even when angry. In contrast, Subjectivists (lowI, HighR), reported the lowest levels of driving anger yet were significantly more likely to endorse aggressive responses. This provides further insight into why high levels of driving anger may not always translate into more aggressive driving.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Failures in industrial organizations dealing with hazardous technologies can have widespread consequences for the safety of the workers and the general population. Psychology can have a major role in contributing to the safe and reliable operation of these technologies. Most current models of safety management in complex sociotechnical systems such as nuclear power plant maintenance are either non-contextual or based on an overly-rational image of an organization. Thus, they fail to grasp either the actual requirements of the work or the socially-constructed nature of the work in question. The general aim of the present study is to develop and test a methodology for contextual assessment of organizational culture in complex sociotechnical systems. This is done by demonstrating the findings that the application of the emerging methodology produces in the domain of maintenance of a nuclear power plant (NPP). The concepts of organizational culture and organizational core task (OCT) are operationalized and tested in the case studies. We argue that when the complexity of the work, technology and social environment is increased, the significance of the most implicit features of organizational culture as a means of coordinating the work and achieving safety and effectiveness of the activities also increases. For this reason a cultural perspective could provide additional insight into the problem of safety management. The present study aims to determine; (1) the elements of the organizational culture in complex sociotechnical systems; (2) the demands the maintenance task sets for the organizational culture; (3) how the current organizational culture at the case organizations supports the perception and fulfilment of the demands of the maintenance work; (4) the similarities and differences between the maintenance cultures at the case organizations, and (5) the necessary assessment of the organizational culture in complex sociotechnical systems. Three in-depth case studies were carried out at the maintenance units of three Nordic NPPs. The case studies employed an iterative and multimethod research strategy. The following methods were used: interviews, CULTURE-survey, seminars, document analysis and group work. Both cultural analysis and task modelling were carried out. The results indicate that organizational culture in complex sociotechnical systems can be characterised according to three qualitatively different elements: structure, internal integration and conceptions. All three of these elements of culture as well as their interrelations have to be considered in organizational assessments or important aspects of the organizational dynamics will be overlooked. On the basis of OCT modelling, the maintenance core task was defined as balancing between three critical demands: anticipating the condition of the plant and conducting preventive maintenance accordingly, reacting to unexpected technical faults and monitoring and reflecting on the effects of maintenance actions and the condition of the plant. The results indicate that safety was highly valued at all three plants, and in that sense they all had strong safety cultures. In other respects the cultural features were quite different, and thus the culturally-accepted means of maintaining high safety also differed. The handicraft nature of maintenance work was emphasised as a source of identity at the NPPs. Overall, the importance of safety was taken for granted, but the cultural norms concerning the appropriate means to guarantee it were little reflected. A sense of control, personal responsibility and organizational changes emerged as challenging issues at all the plants. The study shows that in complex sociotechnical systems it is both necessary and possible to analyse the safety and effectiveness of the organizational culture. Safety in complex sociotechnical systems cannot be understood or managed without understanding the demands of the organizational core task and managing the dynamics between the three elements of the organizational culture.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The recent introduction of the Australian Curriculum: History as a timetabled school subject has enhanced the teaching of history in the primary years. Previously, history was integrated with geography, economics and civics and citizenship; however, in the new curriculum students are introduced to history from their first year at school. The review addresses significant concerns about the scope and content in history in an over-crowded primary curriculum (Donnelly & Wiltshire, 2014; APPA, 2014). However, the history curriculum provides a rare opportunity to explore distinctive content and develop agency by investigating personal, local, national and international contexts. This paper examines the recommendations of the review and the implications for history in the primary years.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Proton spin lattice relaxation (T1) in (CH3)4NCdBr3 at different Larmor frequencies (10, 20 and 30 MHz) has been studied in the temperature range 77 to 400 K. The variations in T1 at high temperature are independent of frequency and show a maximum due to spin rotation- interaction. The other features are interpreted as being due to isotropic tumbling of the tetramethylammonium ion and random reorientation of the CH3 group. The CW spectrum remained narrow up to 77 K and develops a wing structure at low temperatures. This observation is attributed to a possible tunnelling motion of the CH3 group, which has rather low activation energy as demonstrated by the study of T1.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Plasticity in amorphous alloys is associated with strain softening, induced by the creation of additional free volume during deformation. In this paper, the role of free volume, which was a priori in the material, on work softening was investigated. For this, an as-cast Zr-based bulk metallic glass (BMG) was systematically annealed below its glass transition temperature, so as to reduce the free volume content. The bonded-interface indentation technique is used to generate extensively deformed and well defined plastic zones. Nanoindentation was utilized to estimate the hardness of the deformed as well as undeformed regions. The results show that the structural relaxation annealing enhances the hardness and that both the subsurface shear band number density and the plastic zone size decrease with annealing time. The serrations in the nanoindentation load-displacement curves become smoother with structural relaxation. Regardless of the annealing condition, the nanohardness of the deformed regions is similar to 12-15% lower, implying that the prior free volume only changes the yield stress (or hardness) but not the relative flow stress (or the extent of strain softening). Statistical distributions of the nanohardness obtained from deformed and undeformed regions have no overlap, suggesting that shear band number density has no influence on the plastic characteristics of the deformed region.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A series of metabolism experiments investigated the recovery of continuous-, intravenously infused chromium complexed with ethylenediamine tetra-acetic acid (CrEDTA) and lithium sulphate in the urine of cattle with a view to using the markers to estimate urine and metabolite output in grazing cattle. The recovery of Cr in urine from these infusions was similar (90%) in metabolism trials when cattle consumed three very contrasting diets: high-grain formulated pellet, lucerne hay (Medicago sativa) or low-quality native grass hay (predominantly Heteropogon contortus). By contrast, Li recovery in urine averaged 46.3 +/- 0.40% and 72.6 +/- 0.43% for native pasture and lucerne hays, respectively, but was not constant across days. There was negligible transfer of Cr from CrEDTA in blood serum to the rumen or faeces, whereas appreciable quantities of infused Li were found in both. The ratio of urine volume estimated by spot samples and marker dilution of Cr, to urine volume measured gravimetrically, was 1.05. In grazing studies using rumen-fistulated (RF) steers grazing seven different tropical and temperate grass and legume pastures, the ratio of concentrations of purine derivatives (PD) to Cr in spot samples of urine was shown to vary diurnally in the range of 49% to 157% of the average 24 h value. This finding indicated the need for regular sampling of urine to achieve an accurate average value for the PD: Cr ratio in urine for use in estimating urinary PD excretion and hence microbial protein production in the rumen. It was concluded that continuous, intravenous infusion of CrEDTA resulted in a constant recovery of Cr in the urine of cattle across diets and, provided an intensive sampling regime was followed to account for diurnal variation, it would be suitable as a marker to estimate urine volume and urinary output of PD in grazing cattle.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Over the past decade, The biology of Australian weeds series has presented summary chapters about the biology, taxonomy, significance and control of most of Australia's most problematic weeds. Many of these chapters first appear in Plant Protection Quarterly and are then updated and revised for the book. Dane Panetta was also an editor of the second volume. This volume contains chapters of a further sixteen weed species including several of interest to Queensland.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Diffusive transport is a universal phenomenon, throughout both biological and physical sciences, and models of diffusion are routinely used to interrogate diffusion-driven processes. However, most models neglect to take into account the role of volume exclusion, which can significantly alter diffusive transport, particularly within biological systems where the diffusing particles might occupy a significant fraction of the available space. In this work we use a random walk approach to provide a means to reconcile models that incorporate crowding effects on different spatial scales. Our work demonstrates that coarse-grained models incorporating simplified descriptions of excluded volume can be used in many circumstances, but that care must be taken in pushing the coarse-graining process too far.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Complexation of valinomycin (VM) with the divalent cation Ca2+ in a lipophilic solvent, acetonitrile (CH3-CN), has been studied by using circular dichroism and proton and carbon- 13 nuclear magnetic resonance (‘H NMR and I3C NMR). From analyses of the spectral data, it is concluded that VM forms a 2:l (peptideion-peptide) sandwich complex with Ca2+, at low concentration of VM. At moderate conocentrations of the salt, in addition to the sandwich complex, an equimolar (1:l) complex different from those observed for potassium and sodium is also observed. At very large concentrations of the calcium salt, the data suggested a complex with a conformation similar to that of the free VM in polar solvents. Possible conformations for the sandwich and the equimolar VM-calcium complexes are proposed.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A numerical scheme is presented for accurate simulation of fluid flow using the lattice Boltzmann equation (LBE) on unstructured mesh. A finite volume approach is adopted to discretize the LBE on a cell-centered, arbitrary shaped, triangular tessellation. The formulation includes a formal, second order discretization using a Total Variation Diminishing (TVD) scheme for the terms representing advection of the distribution function in physical space, due to microscopic particle motion. The advantage of the LBE approach is exploited by implementing the scheme in a new computer code to run on a parallel computing system. Performance of the new formulation is systematically investigated by simulating four benchmark flows of increasing complexity, namely (1) flow in a plane channel, (2) unsteady Couette flow, (3) flow caused by a moving lid over a 2D square cavity and (4) flow over a circular cylinder. For each of these flows, the present scheme is validated with the results from Navier-Stokes computations as well as lattice Boltzmann simulations on regular mesh. It is shown that the scheme is robust and accurate for the different test problems studied.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

For any construction activity in expansive soils, determination of swelling pressure/heave is an essential step. Though many attempts have been made to develop laboratory procedures by using the laboratory one-dimensional oedometer to determine swelling pressure of expansive soils, they are reported to yield varying results. The main reason for these variations could be heterogeneous moisture distribution of the sample over its thickness. To overcome this variation the experimental procedure should be such that the soil gets fully saturated. Attempts were made to introduce vertical sand drains in addition to the top and bottom drains. In this study five and nine vertical sand drains were introduced to experimentally find out the variations in the swell and swelling pressure. The variations in the moisture content at middle, top, and bottom of the sample in the oedometer test are also reported. It is found that swell-load method is better as compared to zero-swell method. Further, five number of vertical sand drains are found to be sufficient to obtain uniform moisture content distribution.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The nuclear receptor (NR) superfamily is comprised of receptors for small lipopfilic ligands such as steroid hormones, thyroid hormone, retinoids, and vitamin D. NRs are ligand-inducible transcription factors capable of both activating and repressing their target gene expression. They control a wide range of biological functions connected to growth, development, and homeostasis. In addition to the ligand-regulated receptors, the family includes a large group of receptors whose physiological ligands are unknown. These receptors are referred to as orphan NRs. Estrogen-related receptor gamma (ERRgamma) belongs to the ERR subfamily of orphan NRs together with the related ERRalpha and ERRbeta. ERRs share amino acid sequence homology with the classical estrogen receptors (ERs) but they are unable to bind natural estrogenic ligands. ERRgamma is expressed in several embryonic and adult tissues but its biological role is still largely unknown. ERRgamma activates reporter gene expression in transfected cells independently of added hormones implying that ERRgamma harbors constitutive activity. However, the intrinsic activity of ERRgamma can be inhibited by synthetic compounds such as the selective estrogen receptor modulator 4-hydroxytamoxifen (4-OHT). Ligands of NRs can act as agonists that activate transcription, as antagonists that prevent activation of transcription, or as inverse agonists that antagonize the constitutive transcriptional activity of receptor. Most of the synthetic ERRgamma ligands act as inverse agonists but recently, a synthetic ERRgamma agonist GSK4716 was identified. This demonstrates that it is possible to design and identify agonists for ERRgamma. Prior to this thesis work, the structural and functional characteristics of ERRgamma were largely unknown. The aim of this study was to define the functional requirements for ERRgamma-mediated transcriptional regulation and to examine the cross-talk between ERRgamma and other NRs. Due to the fact that natural physiological ligands of ERRgamma are unknown, another aim of this study was to seek new natural compounds that may affect transcriptional activity of ERRgamma. Plant-derived phytoestrogens have previously been shown to act as ligands for ERs and ERRalpha, and therefore the effects of these compounds were also studied on ERRgamma-mediated transcriptional regulation. This work demonstrated that ERRgamma-mediated transcriptional regulation was dependent on DNA-binding, dimerization and activation function-2. Heterodimerization with ERRalpha inhibited the transcriptional activity of ERRgamma. In addition to 4-OHT, another anti-estrogen, 4-hydroxytoremifene (4-OHtor), was identified as an inverse agonist of ERRgamma. Interestingly, ERRgamma activated transcription in the presence of 4-OHT and 4-OHtor on activator protein-1 binding sites. ERRgamma was found to interact with another orphan NR Nurr1 by repressing the ability of Nurr1 to activate transcription of the osteopontin gene. Transcriptional activity of ERRgamma was shown to be stimulated by the phytoestrogen equol. Structural model analysis and mutational experiments indicated that equol was able to bind to the ligand binding domain of ERRgamma. The growth inhibitory effect of ERRgamma on prostate cancer cells was found to be enhanced by equol. In summary, this study demonstrates that despite the absence of an endogenous physiological ligand, the activity of ERRgamma can be modulated in other ways such as dimerization with related receptors or by cross-talk with other transcription factors as well as by binding some synthetic or natural compounds.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this paper, a refined classic noise prediction method based on the VISSIM and FHWA noise prediction model is formulated to analyze the sound level contributed by traffic on the Nanjing Lukou airport connecting freeway before and after widening. The aim of this research is to (i) assess the traffic noise impact on the Nanjing University of Aeronautics and Astronautics (NUAA) campus before and after freeway widening, (ii) compare the prediction results with field data to test the accuracy of this method, (iii) analyze the relationship between traffic characteristics and sound level. The results indicate that the mean difference between model predictions and field measurements is acceptable. The traffic composition impact study indicates that buses (including mid-sized trucks) and heavy goods vehicles contribute a significant proportion of total noise power despite their low traffic volume. In addition, speed analysis offers an explanation for the minor differences in noise level across time periods. Future work will aim at reducing model error, by focusing on noise barrier analysis using the FEM/BEM method and modifying the vehicle noise emission equation by conducting field experimentation.