A comparison of plastic collapse and limit loads for single mitred pipe bends under in-plane bending

This paper presents a comparison of the plastic collapse loads from experimental in-plane bending tests on three 90 degree single un-reinforced mitred pipe bends, with the results from various 3D solid finite element models. The bending load applied reduced the bend angle and in turn, the resulting cross-sectional ovalisation led to a recognised weakening mechanism, which is only observable by testing or by including large displacement effects in the plastic finite element solution. A small displacement limit solution with an elastic-perfectly-plastic material model overestimated the collapse load by 40%. The plastic collapse finite element solution produced excellent agreement with experiment

Decoherence and Quantum-Classical Master Equation Dynamics

The conditions under which quantum-classical Liouville dynamics may be reduced to a master equation are investigated. Systems that can be partitioned into a quantum-classical subsystem interacting with a classical bath are considered. Starting with an exact non-Markovian equation for the diagonal elements of the density matrix, an evolution equation for the subsystem density matrix is derived. One contribution to this equation contains the bath average of a memory kernel that accounts for all coherences in the system. It is shown to be a rapidly decaying function, motivating a Markovian approximation on this term in the evolution equation. The resulting subsystem density matrix equation is still non-Markovian due to the fact that bath degrees of freedom have been projected out of the dynamics. Provided the computation of non-equilibrium average values or correlation functions is considered, the non-Markovian character of this equation can be removed by lifting the equation into the full phase space of the system. This leads to a trajectory description of the dynamics where each fictitious trajectory accounts for decoherence due to the bath degrees of freedom. The results are illustrated by computations of the rate constant of a model nonadiabatic chemical reaction.Comment: 13 pages, 6 figures, revision includes: Added references on mixed quantum-classical Liouville theory, and some minor details that address the comments of the reviewe

Climate change: Why the conspiracy theories are dangerous

Uncertainty surrounds the public understanding of climate change and provides fertile ground for conspiracy theories. Typically, such conspiracy theories assert that climate scientists and politicians are distorting or hijacking the science to suit their own purposes. Climate change conspiracy theories resemble other conspiracy theories in some respects, but in others they appear to be quite different. For example, climate change conspiracy theories appear to be motivated by the desire to deny or minimize an unwelcome and threatening conclusion. They also appear to be more contentious than other types of conspiracy theories. Perhaps to an unparalleled extent, people on both sides of the issue champion climate change conspiracy theories. Finally, more than other conspiracy theories, those concerning climate change appear to be more politically loaded, dividing opinion across the left-right continuum. Some empirical evidence suggests that climate change conspiracy theories may be harmful, steering people away from environmentally friendly initiatives. They therefore present a significant challenge for governments and environmental organizations that are attempting to convince people to take action against global warming

Evaluating disease severity in idiopathic pulmonary fibrosis.

Accurate assessment of idiopathic pulmonary fibrosis (IPF) disease severity is integral to the care provided to patients with IPF. However, to date, there are no generally accepted or validated staging systems. There is an abundance of data on using information acquired from physiological, radiological and pathological parameters, in isolation or in combination, to assess disease severity in IPF. Recently, there has been interest in using serum biomarkers and computed tomography-derived quantitative lung fibrosis measures to stage disease severity in IPF. This review will focus on the suggested methods for staging IPF, at baseline and on serial assessment, their strengths and limitations, as well as future developments

Evaluation of Voting with Form Dropout Techniques for Ballot Vote Counting

Vote counting accuracy has become a well-known issue in the vote collection process. Digital image processing techniques can be incorporated in the analysis of printed election ballots. Current image processing techniques in the vote collection process are heavily dependent on the anticipated, geometric positioning of the vote. These techniques don’t account for markings made outside of the requested field of input. Using various form dropout techniques, however, every mark on the form can be extracted and used by the machine to make an intelligent decision. Most methods will still miss a few marks and result in a few false alarms. This paper explores methods of voting between the results of the different mark extraction methods to improve recognition. To provide diversity a simple image subtraction technique is paired with a distance transform and a morphology based algorithm. The result has a higher detection rate and a lower false alarm rate

Status of Kilowatt-Class Stirling Power Conversion Using a Pumped NaK Loop for Thermal Input

Free-piston Stirling power conversion has been identified as a viable option for potential Fission Surface Power (FSP) systems on the Moon and Mars. Proposed systems consist of two or more Stirling convertors, in a dual-opposed configuration, coupled to a low-temperature uranium-dioxide-fueled, liquid-metal-cooled reactor. To reduce developmental risks associated with liquid-metal loop integration, a test rig has been built to evaluate the performance of a pair of 1-kW free-piston Stirling convertors using a pumped sodium-potassium (NaK) loop for thermal energy input. Baseline performance maps have been generated at the Glenn Research Center (GRC) for these 1-kW convertors operating with an electric heat source. Each convertor was then retrofitted with a custom-made NaK heater head and integrated into a pumped NaK system at the Marshall Space Flight Center (MSFC). This paper documents baseline testing at GRC as well as the progress made in integrating the Stirling convertors into the pumped NaK loop

Catalytic Hydrotreatment of Biomass-Derived Fast Pyrolysis Liquids Using Ni and Cu-Based PRICAT Catalysts

Biomass-derived fast pyrolysis liquids (PLs) are not directly applicable as transportation fuels due to their high oxygen content and limited storage stability. Catalytic hydrotreatment is an efficient technology to convert such PLs to finished fuels or intermediates that can be used as a co-feed for existing oil refinery units. In this paper, we report catalyst screening studies for the mild hydrotreatment of PLs using commercially available Ni and Cu-based PRICAT catalysts at rather mild conditions (200 °C, initial 140 bar H2pressure) in a batch setup for 4 h. Among all catalysts, PRICAT NI 62/15 showed the best performance for mild catalytic hydrotreatment in terms of product properties (highest H/C ratio and lowest TG residue). The best catalysts were also tested for deep hydrotreatment at more severe conditions (350 °C, initial 100 bar H2pressure). Here, the PRICAT NI catalysts showed better performance than the benchmark Picula Ni-Mo catalyst when considering oil yield and H/C ratio. Advantageously, the hydrogen consumption during deep hydrotreatment is also reduced, rationalized by a lower methanation activity

Receivers Limit the Prevalence of Deception in Humans: Evidence from Diving Behaviour in Soccer Players

Deception remains a hotly debated topic in evolutionary and behavioural research. Our understanding of what impedes or facilitates the use and detection of deceptive signals in humans is still largely limited to studies of verbal deception under laboratory conditions. Recent theoretical models of non-human behaviour have suggested that the potential outcome for deceivers and the ability of receivers to discriminate signals can effectively maintain their honesty. In this paper, we empirically test these predictions in a real-world case of human deception, simulation in soccer. In support of theoretical predictions in signalling theory, we show that cost-free deceit by soccer players decreases as the potential outcome for the signaller becomes more costly. We further show that the ability of receivers (referees) to detect deceptive signals may limit the prevalence of deception by soccer players. Our study provides empirical support to recent theoretical models in signalling theory, and identifies conditions that may facilitate human deception and hinder its detection