Short-distance and short-time structure of a unitary Fermi gas

We consider the operator product expansions for unitarity fermions. We compute the dynamic structure factor S(q,w) at large frequency and wavenumber away from the one-particle peak. The overall normalization of S(q,w) is determined by Tan's contact parameter, and the dependence on q and w is obtained in closed analytic form. We also find energy deposited into the system by small, rapid variations of the inverse scattering length.Comment: 11 pages, 8 figure

Absorption of pyrimidines, purines, and nucleosides by Co, Ni, Cu and Fe /III-montmorillonite /clay-organic studies XIII/

Absorption of pyrimidines, purines, and nucleosides by copper, nickel, cobalt, and iron montmorillonit

Absorption of pyrimidines, purines and nucleosides by Li, Na, Mg, and Ca montmorillonite /clay organic studies 12/

Absorption of purines, pyrimidines, and nucleoside in aqueous solution by montmorillionite occurring as cation exchange reactio

Development and validation of the crew-station system-integration research facility

The various issues associated with the use of integrated flight management systems in aircraft were discussed. To address these issues a fixed base integrated flight research (IFR) simulation of a helicopter was developed to support experiments that contribute to the understanding of design criteria for rotorcraft cockpits incorporating advanced integrated flight management systems. A validation experiment was conducted that demonstrates the main features of the facility and the capability to conduct crew/system integration research

The New Element Californium (Atomic Number 98)

Definite identification has been made of an isotope of the element with atomic number 98 through the irradiation of Cm{sup 242} with about 35-Mev helium ions in the Berkeley Crocker Laboratory 60-inch cyclotron. The isotope which has been identified has an observed half-life of about 45 minutes and is thought to have the mass number 244. The observed mode of decay of 98{sup 244} is through the emission of alpha-particles, with energy of about 7.1 Mev, which agrees with predictions. Other considerations involving the systematics of radioactivity in this region indicate that it should also be unstable toward decay by electron capture. The chemical separation and identification of the new element was accomplished through the use of ion exchange adsorption methods employing the resin Dowex-50. The element 98 isotope appears in the eka-dysprosium position on elution curves containing berkelium and curium as reference points--that is, it precedes berkelium and curium off the column in like manner that dysprosium precedes terbium and gadolinium. The experiments so far have revealed only the tripositive oxidation state of eka-dysprosium character and suggest either that higher oxidation states are not stable in aqueous solutions or that the rates of oxidation are slow. The successful identification of so small an amount of an isotope of element 98 was possible only through having made accurate predictions of the chemical and radioactive properties

‘mere prattle without practice’: Authorship in Performance

Over the last ten years there has been a struggle within Shakespeare studies between the vast majority of scholars who have remained committed to the orthodox view on Shakespeare’s authorship of the plays that bear his name and a much smaller group of scholars, working with profoundly different levels of rigour, who have sought to question this position. Recently there has been a degree of agreement that it is more productive to approach the issue in terms of acknowledging the collaborative nature of early modern play writing. It is noticeable, however, that for the literary critics and historians involved in this debate collaboration seems to end at the playhouse’s door. There is an assumption that the collaborators who produced early modern drama were all writers and not the other people involved in the production of Tudor and Stuart plays. This is profoundly problematic. In this article, Thomas Betteridge and Greg Thompson propose a non-textual approach to the authorship question through the use of performance as a research technique. The first part of the article will map out the current ground of Shakespeare authorship studies while the second part is an account of a performance as research workshop carried out by Betteridge and Thompson with students from Brunel University, London

A ratio model of perceived speed in the human visual system

The perceived speed of moving images changes over time. Prolonged viewing of a pattern (adaptation) leads to an exponential decrease in its perceived speed. Similarly, responses of neurones tuned to motion reduce exponentially over time. It is tempting to link these phenomena. However, under certain conditions, perceived speed increases after adaptation and the time course of these perceptual effects varies widely. We propose a model that comprises two temporally tuned mechanisms whose sensitivities reduce exponentially over time. Perceived speed is taken as the ratio of these filters' outputs. The model captures increases and decreases in perceived speed following adaptation and describes our data well with just four free parameters. Whilst the model captures perceptual time courses that vary widely, parameter estimates for the time constants of the underlying filters are in good agreement with estimates of the time course of adaptation of direction selective neurones in the mammalian visual system