Diamond drilling for core sampling

The drilling for, and recovery of core samples from the earth's crust, sometimes at distances of up to 3 km from the surface, is subject to many practical problems. One of these problems involves the jamming of core samples inside the recovery cylinder during drilling. There is a need to analyse the forces involved when the recovery cylinder is sliding over the core. Several simple mechanisms associated with naturally occurring variations in rock and soil structure were suggested as possible causes of jamming. The results suggest that the simplest mechanisms are not the cause of the problem, but combinations of these simple mechanisms might well be the cause. The results and discussion indicate some experiments that would be useful in a further study of the problem, and data from the drilling operations that should be kept for further analysis

Use of detergent in wool scouring

Wool scouring processes have been the subject of considerable analysis in recent years. However the necessary amount of detergent needed is still controlled by the personal judgement of experienced operators. No detergent measurement procedure, effective for commercial operation, is known. Optimal control of addition of detergent would naturally lead to reduced cost. This report is an attempt to analyse the detergent requirement of a wool scouring process with suggestions for further work

Relativity as Support for Presentism: A Modest Evidential Argument

Presentism is roughly the view that only the present exists. This view requires an absolute simultaneity relation. The special theory of relativity, however, is highly successful and does not account for absolute simultaneity. This is widely regarded as an evidential threat to presentism. In what follows, I propose a modest evidential argument in support of presentism on the basis of the physical evidence itself. A weak relativity postulate is shown to follow from a weak light-speed postulate. The weak light-speed postulate, in turn, is shown to be more probable on presentism than on its main rival doctrine, eternalism. Specifically, when one accounts for possible worlds in which the space-time metric is Euclidean (+,+,+,+) rather than Lorentzian (-,+,+,+), the empirical evidence turns out to be more probable on presentism than on eternalism. If successful, this argument provides modest evidential support for presentism and against eternalism. However, the support is drawn from an unexpected source: the physical evidence itself

Preparedness, crisis management and policy change : EMU at the critical juncture of 2008-2013

Focusing on the role of the European Central Bank during the recent banking and sovereign debt crisis in the euro area, this article contributes to the literature on ideational and institu-tional change at critical junctures. In line with recent calls to take the temporal dimension of political change seriously, the article argues that in the context of explosive economic crises a phase of emergency crisis management precedes the phase of purposeful institution building. What happens during this phase is crucial, for in spite of their improvised charac-ter emergency crisis management measures create their own path dependencies. This, how-ever, raises the question of why crisis managers act the way they do. While it is true that crisis managers act as bricoleurs who use whichever tools they find at their disposal, the question of why certain tools are available rather than others calls for a historicisation of crisis management. The article therefore introduces the variable of preparedness, which measures the extent to which the pre-crisis policy paradigm was prepared for the occur-rence of, in this case, the combination of a systemic banking crisis and a sovereign debt cri-sis. The empirical section then compares pre-crisis contingency planning and in-crisis contingency acting, revealing several inconsistencies in the pre-crisis crisis paradigm. The analysis matters for our understanding of political change because these inconsistencies caused the ECB to assume a dominant position in the euro area during the emergency phase of the crisis. This windfall gain in power for the ECB has already begun to shape the future ideational and institutional order of the euro area

Infinitesimally Nonlocal Lorentz Violation

We introduce a new Lorentz-violating modification to a scalar quantum field theory. This interaction, while super-renormalizable by power counting, is fundamentally different from the interactions previously considered within the Lorentz-violating standard model extension. The Lagrange density is nonlocal, because of the presence of a Hilbert transform term; however, this nonlocality is also very weak. The theory has reasonable stability and causality properties and, although the Lorentz-violating interaction possesses a single vector index, the theory is nonetheless CPT even. As an application, we analyze the possible effects of this new form of Lorentz violation on neutral meson oscillations. We find that under certain circumstances, the interaction may lead to quite peculiar sidereal modulations in the oscillation frequency.Comment: 10 page

Long-range order for the spin-1 Heisenberg model with a small antiferromagnetic interaction

We look at the general SU(2) invariant spin-1 Heisenberg model. This family includes the well known Heisenberg ferromagnet and antiferromagnet as well as the interesting nematic (biquadratic) and the largely mysterious staggered-nematic interaction. Long range order is proved using the method of reflection positivity and infrared bounds on a purely nematic interaction. This is achieved through the use of a type of matrix representation of the interaction making clear several identities that would not otherwise be noticed. Using the reflection positivity of the antiferromagnetic interaction one can then show that the result is maintained if we also include an antiferromagnetic interaction that is sufficiently small.Comment: 15 pages, 1 figur

Speeding up neighborhood search in local Gaussian process prediction

Recent implementations of local approximate Gaussian process models have pushed computational boundaries for non-linear, non-parametric prediction problems, particularly when deployed as emulators for computer experiments. Their flavor of spatially independent computation accommodates massive parallelization, meaning that they can handle designs two or more orders of magnitude larger than previously. However, accomplishing that feat can still require massive supercomputing resources. Here we aim to ease that burden. We study how predictive variance is reduced as local designs are built up for prediction. We then observe how the exhaustive and discrete nature of an important search subroutine involved in building such local designs may be overly conservative. Rather, we suggest that searching the space radially, i.e., continuously along rays emanating from the predictive location of interest, is a far thriftier alternative. Our empirical work demonstrates that ray-based search yields predictors with accuracy comparable to exhaustive search, but in a fraction of the time - bringing a supercomputer implementation back onto the desktop.Comment: 24 pages, 5 figures, 4 table

The mistake of 1937: a general equilibrium anlaysis

This paper studies a dynamic general equilibrium model with sticky prices and rational expectations in an environment of low interest rates and deflationary pressures. We show that small changes in the public’s beliefs about the future inflation target of the government can lead to large swings in both inflation and output. This effect is much larger at low interest rates than under regular circumstances. This highlights the importance of effective communication policy at zero interest rates. We argue that confusing communications by the US Federal Reserve, the President of the United States, and key administration officials about future price objectives were responsible for the sharp recession in the US in 1937-38, one of the sharpest recessions in US economic history. Poor communication policy is the mistake of 1937. Before committing the mistake of 1937 the US policy makers faced economic conditions that are similar in some respect to those confronted by Japanese policy makers in the first half of 2006. JEL Classification: E32, E52, E6