3,066 research outputs found
Mach's Principle and Model for a Broken Symmetric Theory of Gravity
We investigate spontaneous symmetry breaking in a conformally invariant
gravitational model. In particular, we use a conformally invariant scalar
tensor theory as the vacuum sector of a gravitational model to examine the idea
that gravitational coupling may be the result of a spontaneous symmetry
breaking. In this model matter is taken to be coupled with a metric which is
different but conformally related to the metric appearing explicitly in the
vacuum sector. We show that after the spontaneous symmetry breaking the
resulting theory is consistent with Mach's principle in the sense that inertial
masses of particles have variable configurations in a cosmological context.
Moreover, our analysis allows to construct a mechanism in which the resulting
large vacuum energy density relaxes during evolution of the universe.Comment: 9 pages, no figure
Large magnetoresistance using hybrid spin filter devices
A magnetic "spin filter" tunnel barrier, sandwiched between a non-magnetic
metal and a magnetic metal, is used to create a new magnetoresistive tunnel
device, somewhat analogous to an optical polarizer-analyzer configuration. The
resistance of these trilayer structures depends on the relative magnetization
orientation of the spin filter and the ferromagnetic electrode. The spin
filtering in this configuration yields a previously unobserved
magnetoresistance effect, exceeding 100%.Comment: 3.5 pages, 3 figures, submitted to Appl. Phys. Let
Stimulated by Novelty? The role of Psychological Needs and Perceived Creativity
In the current research we aimed to address the inconsistent finding in the brainstorming literature that cognitive stimulation sometimes results from novel input, yet other times from non-novel input. We expected and found, in three experiments, that the strength and valence of this relationship is moderated by people's psychological needs for structure and autonomy. Specifically, the effect of novel input (vs. non-novel input), through perceived creativity, on cognitive stimulation was stronger for people who were either low in need for structure or high in need for autonomy. Also, when the input people received did not fit their needs, they experienced less psychological cognitive stimulation from this input (i.e., less task enjoyment and feeling more blocked) compared with when they did not receive any input. Hence, to create the ideal circumstances for people to achieve cognitive stimulation when brainstorming, input novelty should be aligned with their psychological needs
Durability aspects of electrochemical realkalisation treatment
Electrochemical realkalisation (ER) is a technique used for the repair of concrete suffering carbonation-induced corrosion of steel reinforcement. It aims at restoring high levels of pH through the application of a temporary cathodic current to steel, and subsequent production of alkalinity at the steel surface; a further mechanism of realkalisation relies on the ingress of an alkaline solution in the concrete through the surface in contact with the anode. ER does not require the replacement of carbonated concrete, if it is not damaged, and so it can be advantageous compared to conventional repair, that usually requires the removal of large amounts of mechanically sound concrete. Although ER was introduced in the 1980s and has been used since then for the repair of carbonated structures, there are still some aspects connected with its application that need further investigation. This paper presents the results of an experimental research aimed at investigating the durability of ER, considering both the realkalisation of carbonated mortar and the protection of reinforcement from corrosion
Effects on Cancer Prevention from the COVID-19 Pandemic
The COVID-19 pandemic led to disruption of health services around the world, including cancer services. We carried out a narrative review of the effect of the pandemic on cancer prevention services, including screening. Services were severely affected in the early months of the pandemic, and in some areas are still recovering. Large numbers of additional cancers or additional late-stage cancers have been predicted to arise over the coming years as a result of this disruption. To minimize the effects on cancer outcomes, it is necessary to return as quickly as possible to prepandemic levels of screening and prevention activity or indeed to exceed these levels. The recovery of services should address health inequalities.</p
Putting the public back in behavioral public policy
Behavioral public policies are aimed at influencing the behavior of the public in a way that is advantageous for the public itself and within the law. Sanders, Snijders and Hallsworth (2018 , this issue) summarize the state of the art of this new field of study and introduce a number of challenges and opportunities for the time to come. We address an additional challenge that is present and central in all attempts to influence behavior, namely the public – the people that are the target of behavioral public policies. We review evidence revealing that people do not passively accept those influence attempts, but often show reactant responses. We propose that the Persuasion Knowledge Model provides a framework both to understand the reactions of the public and to facilitate communication between academic researchers and practitioners
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