Erosion versus construction: The origin of Venusian channels

Lava channels are a common feature in the volcanic regions of the Moon, and have now been observed on Venus. There has been much debate about the origin of lunar channels as to whether they are the result of erosional (either thermal or mechanical) or constructional processes. It is necessary to determine the criteria to distinguish between the different types of channels. The clearest evidence is that the presence of levees indicates that the channel experienced a constructional phase for a period. One example of a channel of this type in the southeast region of Aphrodite Terra appears to show both erosional and constructional characteristics. It is approximately 700 km long with an average width of about 1 km. It drops a distance of 700 m from beginning to end, which means that the average slope is 0.06 degrees. Its source may have been a graben situated at the northwest end of the channel. It appears to have different origins along its length. The lack of levees near the source suggests that the channel is erosional in this region. The presence of levees indicates that a constructional phase has occurred. These are formed by lava repeatedly splashing over the channel sides and solidifying. Evidence of levees is seen further away from the source. However, the presence of levees does not mean that the lava was not also eroding and deepening the channel. Thus, in conclusion, our example channel is very sinuous and there is evidence of erosion. There may also have been overflow here. In its middle reaches it roofs over and has the characteristics of a lava tube. In the lower reaches there is strong evidence for the presence of levees indicating construction. On Earth, limited amounts of erosion may occur in basaltic lava channels, although not nearly on the same scale as on the planets just mentioned. For lava erosion on Earth to occur to a comparable extent, excessive eruption times are required. However, low-viscosity komatiite lava may erode to a larger extent and there is direct evidence that carbonatite lava erodes when the underlying strata is also carbonatite. Previously, it has always been assumed that for thermal erosion to occur the flow must be turbulent. Recent findings indicate that this may be a false assumption and that laminar flow may be effective in eroding the substrate

DScent Final Report

DScent was a joint project between five UK universities combining research theories in the disciplines of computational inference, forensic psychology and expert decision-making in the area of counter-terrorism. This document discusses the work carried out by Leeds Metropolitan University which covers the research, design and development work of an investigator support system in the area of deception using artificial intelligence. For the purposes of data generation along with system and hypothesis testing the project team devised two closed world games, the Cutting Corners Board Game and the Location Based Game. DScentTrail presents the investigator with a ‘scent trail’ of a suspect’s behaviour over time, allowing the investigator to present multiple challenges to a suspect from which they may prove the suspect guilty outright or receive cognitive or emotional clues of deception (Ekman 2002; Ekman & Frank 1993; Ekman & Yuille 1989; Hocking & Leathers 1980; Knapp & Comadena 1979). A scent trail is a collection of ordered, relevant behavioural information over time for a suspect. There are links into a neural network, which attempts to identify deceptive behavioural patterns of individuals. Preliminary work was carried out on a behavioural based AI module which would work separately alongside the neural network, with both identifying deception before integrating their results to update DScentTrail. Unfortunately the data that was necessary to design such a system was not provided and therefore, this section of research only reached its preliminary stages. To date research has shown that there are no specific patterns of deceptive behaviour that are consistent in all people, across all situations (Zuckerman 1981). DScentTrail is a decision support system, incorporating artificial intelligence (AI), which is intended to be used by investigators and attempts to find ways around the problem stated by Zuckerman above

Tests for cream sediment

Commercial milk plants have employed the sediment test for milk for many years. In fact, the milk sediment test has its place on the milk score card. The amount of sediment is always determined in scoring milk. The test is extremely simple; it consists of passing 1 pint of milk through a sediment tester and catching the sediment present in the milk on a circular pad 1 inch in diameter. The application of a sediment test to cream, on the other hand, has been attempted only very recently. A test as simple as that for milk is impossible. The cream’s high fat content necessitates warming it to melt the fat so that the sample will filter easily; the variable acidity of cream for butter-making necessitates the use of a neutralizing agent, in many instances in order that the filter pad will not clog. Because of the high fat content of the cream it is imperative to use less than a pint in order to reduce the cost and eliminate the handling of a bulky sample after dilution

The Dynamics of Rapidly Emplaced Terrestrial Lava Flows and Implications for Planetary Volcanism

The Kaupulehu 1800-1801 lava flow of Hualalai volcano and the 1823 Keaiwa flow from the Great Crack of the Kilauea southwest rift zone had certain unusual and possibly unique properties for terrestrial basaltic lava flows. Both flows apparently had very low viscosities, high effusion rates, and uncommonly rapid rates of advance. Ultramafic xenolith nodules in the 1801 flow form stacks of cobbles with lava rinds of only millimeter thicknesses. The velocity of the lava stream in the 1801 flow was extremely high, at least 10 m/s (more than 40 km/h). Observations and geological evidence suggest similarly high velocities for the 1823 flow. The unusual eruption conditions that produced these lava flows suggest a floodlike mode of emplacement unlike that of most other present-day flows. Although considerable effort has gone into understanding the viscous fluid dynamics and thermal processes that often occur in basaltic flows, the unusual conditions prevalent for the Kaupulehu and Keaiwa flows necessitate different modeling considerations. We propose an elementary flood model for this type of lava emplacement and show that it produces consistent agreement with the overall dimensions of the flow, channel sizes, and other supporting field evidence. The reconstructed dynamics of these rapidly emplaced terrestrial lava flows provide significant insights about the nature of these eruptions and their analogs in planetary volcanism

Calculation of energy levels and transition amplitudes for barium and radium

The radium atom is a promising system for studying parity and time invariance violating weak interactions. However, available experimental spectroscopic data for radium is insufficient for designing an optimal experimental setup. We calculate the energy levels and transition amplitudes for radium states of significant interest. Forty states corresponding to all possible configurations consisting of the $7s$, $7p$ and $6d$ single-electron states as well as the states of the $7s8s$, $7s8p$ and $7s7d$ configurations have been calculated. The energies of ten of these states corresponding to the $6d^2$, $7s8s$, $7p^2$, and $6d7p$ configurations are not known from experiment. Calculations for barium are used to control the accuracy.Comment: 12 pages, 4 table

PT-symmetric deformations of Calogero models

We demonstrate that Coxeter groups allow for complex PT-symmetric deformations across the boundaries of all Weyl chambers. We compute the explicit deformations for the A2 and G2-Coxeter group and apply these constructions to Calogero–Moser–Sutherland models invariant under the extended Coxeter groups. The eigenspectra for the deformed models are real and contain the spectra of the undeformed case as subsystems

Emplacement of Xenolith Nodules in the Kaupulehu Lava Flow, Hualalai Volcano, Hawaii

The basaltic Kaupulehu 1800-1801 lava flow of Hualalai Volcano, Hawaii contains abundant ultramafic xenoliths. Many of these xenoliths occur as bedded layers of semi-rounded nodules, each thinly coated with a veneer (typically 1 mm thick) of lava. The nodule beds are analogous to cobble deposits of fluvial sedimentary systems. Although several mechanisms have been proposed for the formation of the nodule beds, it was found that, at more than one locality, the nodule beds are overbank levee deposits. The geological occurrence of the nodules, certain diagnostic aspects of the flow morphology and consideration of the inferred emplacement process indicate that the Kaupulehu flow had an exceptionally low viscosity on eruption and that the flow of the lava stream was extremely rapid, with flow velocities of at least 10 m/s (more than 40 km/h. This flow is the youngest on Hualalai Volcano and future eruptions of a similar type would pose considerable hazard to life as well as property

Closing the circle: is it feasible to rehabilitate reefs with sexually propagated corals?

Sexual propagation of corals specifically for reef rehabilitation remains largely experimental. In this study, we refined low technology culture and transplantation approaches and assessed the role of colony size and age, at time of transfer from nursery to reef, on subsequent survival. Larvae from Acropora millepora were reared from gametes and settled on engineered substrates, called coral plug-ins, that were designed to simplify transplantation to areas of degraded reef. Plug-ins, with laboratory spawned and settled coral recruits attached, were maintained in nurseries until they were at least 7 months old before being transplanted to replicate coral limestone outcrops within a marine protected area until they were 31 months old. Survival rates of transplanted corals that remained at the protected in situ nursery the longest were 3.9–5.6 times higher than corals transplanted to the reef earlier, demonstrating that an intermediate ocean nursery stage is critical in the sexual propagation of corals for reef rehabilitation. 3 years post-settlement, colonies were reproductively mature, making this one of few published studies to date to rear a broadcasting scleractinian from eggs to spawning adults. While our data show that it is technically feasible to transplant sexually propagated corals and rear them until maturity, producing a single 2.5-year-old coral on the reef cost at least US$60. ‘What if’ scenarios indicate that the cost per transplantable coral could be reduced by almost 80 %, nevertheless, it is likely that the high cost per coral using sexual propagation methods would constrain delivery of new corals to relatively small scales in many countries with coral reefs.Published versio