Crystal nucleation in glass-forming alloy and pure metal melts under containerless and vibrationless conditions

The undercooling behavior of large spheroids of Pd40Ni40P40 was investigated. By surface etching, supporting the specimens on a fused silica substrate, and successive heating and cooling, crystallization can be eliminated, presumable due to the removal of surface heterogeneities. By this method samples up to 3.2g with a 0.53 mm minor diameter, were made entirely glassy, except for some superficial crystals comprising less than 0.5% of the volume. These experiments show that a cooling rate of approximately 1 K/sec is adequate to avoid copious homogeneous nucleation in the alloy, and that by eliminating or reducing the effectiveness of heterogeneous nucleation sites, it is possible to form bulk samples of this metallic glass with virtually unlimited dimensions

Price Formation under Small Numbers Competition: Evidence from Land Auctions in Singapore

This paper examines the price formation process under small numbers competition using data from Singapore land auctions. The theory predicts that bid prices are less than the zero-profit asset value in these first-price sealed-bid auctions. The model also shows that expected sales price increases with the number of bidders both because each bidder has an incentive to offer a higher price and because of a greater likelihood that a high-value bidder is present. The empirical estimates are consistent with auction theory and show that the standard land attributes are reflected in auction prices as expected. Working Paper No. 04-0

Studies on dorsal fin rot in farmed Atlantic salmon (Salmo salar L.) parr

Aspects of dorsal fin rot in farmed Atlantic salmon parr were investigated and the associated pathology described. Substantial evidence was obtained which suggested that the condition was caused and maintained by repeated bites from other parr. The gross histological and scanning electron microscopic appearance of the lesions were consistent with bite wounds and the typical pathology was reproduced by repeated simulated bites. During behavioural experiments the parr were observed to both bite and damage each others dorsal fins. The typical nodular lesions were more prevalent and took longer to heal at lower temperatures. Dorsal fin rot was found to occur in the absence of damage to the other fins and was more severe in smaller fish. The bacteria associated with the natural lesions and following controlled damage were studied, but not found to play a significant role in the aetiology. They were capable of neither initiating nor maintaining the lesions. The main site of bacterial colonisation appeared to be on exposed fin rays. It was demonstrated that the natural lesions started to resolve as soon as the fish were placed in isolation. A limited study failed to demonstrate a definite relationship between dorsal fin rot and increased susceptibility to Aeromonas salmonicida infection. The implications of all these findings for control of the condition are discussed

List Price Information in Residential Appraisal and Underwriting

This article examines the usefulness of listing prices as leading indicators of house values and as predictors of the direction of housing markets. With Multiple Listing Service data from a large metropolitan area, we create two price indexes, using first listing price and then selling price as the dependent variable in the hedonic regressions. The market is then geographically and categorically segmented, and Granger causality tests are performed to analyze the leading aspect of list prices in the list price-sales price relationship. We find that different segments of the market perform quite differently over the time period of our study, suggesting that for data-based appraisal purposes care is needed in determining the manner and level of aggregation. We also find, however, that market list prices continue to convey important information about subsequent selling prices in most market segments.

Signature of nearly icosahedral structures in liquid and supercooled liquid Copper

A growing body of experiments display indirect evidence of icosahedral structures in supercooled liquid metals. Computer simulations provide more direct evidence but generally rely on approximate interatomic potentials of unproven accuracy. We use first-principles molecular dynamics simulations to generate realistic atomic configurations, providing structural detail not directly available from experiment, based on interatomic forces that are more reliable than conventional simulations. We analyze liquid copper, for which recent experimental results are available for comparison, to quantify the degree of local icosahedral and polytetrahedral order

b anti-b Higgs production at the LHC: Yukawa corrections and the leading Landau singularity

At tree-level Higgs production in association with a b-quark pair proceeds through the small Yukawa bottom coupling in the Standard Model. Even in the limit where this coupling vanishes, electroweak one-loop effects, through the top-Higgs Yukawa coupling in particular, can still trigger this reaction. This contribution is small for Higgs masses around 120GeV but it quickly picks up for higher Higgs masses especially because the one-loop amplitude develops a leading Landau singularity and new thresholds open up. These effects can be viewed as the production of a pair of top quarks which rescatter to give rise to Higgs production through WW fusion. We study the leading Landau singularity in detail. Since this singularity is not integrable when the one-loop amplitude is squared, we regulate the cross section by taking into account the width of the internal top and W particles. This requires that we extend the usual box one-loop function to the case of imaginary masses. We show how this can be implemented analytically in our case. We study in some detail the cross section at the LHC as a function of the Higgs mass and show how some distributions can be drastically affected compared to the tree-level result.Comment: 48 pages, 20 figures. Phys.Rev.D accepted version. Conclusions unchanged, minor changes and references adde

“Skittles & Red Bull is my favourite flavour”: E-cigarettes, smoking, vaping and the changing landscape of nicotine consumption amongst British teenagers – implications for the normalisation debate

Aims: From an academic discourse explaining trends in drug-related attitudes and behaviours, “normalisation” now also encompasses public health policy advocating “denormalisation” of smoking. This study explored young people’s attitudes and behaviours to cigarettes and e-cigarettes to ascertain whether a process of “renormalisation” was underway. Methods: A six-month multi-method study was conducted in NW England. Data collection in April-July 2014 included a convenience sample survey of 233 students; secondary analysis of a 3,500 respondent survey; stakeholder interviews; participant observation sessions; focus groups; and participatory research events with over 100 students. Findings: With the public performance of “vaping” valued as an indicator of experienced use, young people used e-cigarettes primarily for flavour combinations and to perform “tricks”. Smoking cessation and nicotine consumption were less important motivations. When comparing e-cigarettes with eight indicators of normalisation – additionally, legal status and risk perception – there were indications of a growing cultural accommodation of “vaping”. Conclusion: The changing landscape of nicotine and non-nicotine products challenges traditional conceptualisations of “smoking” and “non-smoking” and problematises the notion of linear processes of normalisation in respect not just of young people’s tobacco and nicotine use, but more generally, of delivery systems and the drugs dispensed within them, suggesting marketplace-differentiated normalisation

Stuck in a moment, Concreteness and psychotherapy after acquired brain injury.

This paper surveys the issue of concrete thinking after brain injury—a phenomenon that is widely recognised clinically, but under-investigated in formal research settings. Through the lens of the classical work of Kurt Goldstein the paper outlines the diverse clinical manifestations of concreteness, and the barriers which this might present to the psychotherapeutic process. However, the paper also outlines the way in which preserved psychological functions in highly concrete patients, specially the capacity to focus on immediate reality, and experience emotions in present time, can be used as a lever for psychotherapeutic interventions. The paper concludes with a range of practical suggestions which may aid the psychotherapist in reaching out to this challenging patient group

The Two-Dimensional Square-Lattice S=1/2 Antiferromagnet Cu(pz)2_2(ClO4_4)2_2

We present an experimental study of the two-dimensional S=1/2 square-lattice antiferromagnet Cu(pz)$_2$(ClO$_4$)$_2$ (pz denotes pyrazine - $C_4H_4N_2$) using specific heat measurements, neutron diffraction and cold-neutron spectroscopy. The magnetic field dependence of the magnetic ordering temperature was determined from specific heat measurements for fields perpendicular and parallel to the square-lattice planes, showing identical field-temperature phase diagrams. This suggest that spin anisotropies in Cu(pz)$_2$(ClO$_4$)$_2$ are small. The ordered antiferromagnetic structure is a collinear arrangement with the magnetic moments along either the crystallographic b- or c-axis. The estimated ordered magnetic moment at zero field is m_0=0.47(5)mu_B and thus much smaller than the available single-ion magnetic moment. This is evidence for strong quantum fluctuations in the ordered magnetic phase of Cu(pz)$_2$(ClO$_4$)$_2$. Magnetic fields applied perpendicular to the square-lattice planes lead to an increase of the antiferromagnetically ordered moment to m_0=0.93(5)mu_B at mu_0H=13.5T - evidence that magnetic fields quench quantum fluctuations. Neutron spectroscopy reveals the presence of a gapped spin excitations at the antiferromagnetic zone center, and it can be explained with a slightly anisotropic nearest neighbor exchange coupling described by J_1^{xy}=1.563(13)meV and J_1^z=0.9979(2)J_1^{xy}