Contributions of Vacuum and Plasmon Modes to the Force on a Small Sphere near a Plate

The force on a small sphere with a plasma model dielectric function and in the presence of a perfectly reflecting plane is considered. The contribution of both the vacuum modes of the quantized electromagnetic field and of plasmon modes in the sphere are discussed. In the case that the plasmon modes are in their ground state, quasi-oscillatory terms from the vacuum and plasmon parts cancel one another, leading a monotonic attractive force. If the plasmon modes are not in the ground state, the net force is quasi-oscillatory. In both cases, the sphere behaves in the same way as does an atom in either its ground state or an excited state.Comment: 7 pages, no figures, talk presented at "Quantum Fields under External Conditions - 2005", Barcelona, Spain, September 200

The Casimir effect for thin plasma sheets and the role of the surface plasmons

We consider the Casimir force betweeen two dielectric bodies described by the plasma model and between two infinitely thin plasma sheets. In both cases in addition to the photon modes surface plasmons are present in the spectrum of the electromagnetic field. We investigate the contribution of both types of modes to the Casimir force and confirm resp. find in both models large compensations between the plasmon modes themselves and between them and the photon modes especially at large distances. Our conclusion is that the separation of the vacuum energy into plasmon and photon contributions must be handled with care except for the case of small separations.Comment: submitted to JPhysA Special Issue QFEXT'05, replaced due to a wrong Latex comman

Reducing Reoffending: Review of Selected Countries: Final Review for Audit Scotland

The report reviews reoffending patterns in Scotland, England and Wales, Ireland, Northern Ireland, Norway and New Zealand to establish relevant conditions for different rates of reoffending. A significant part of the report, however, is given over to a critical examination of the concept of 'reoffending' itself which is more a measure of criminal justice agency behaviour than individual behaviour. The report concludes with some suggestions for moving beyond such thin, technocratic understanding of reoffending and rehabilitation. This work was commissioned by and submitted to Audit Scotland

Diffraction in time: An exactly solvable model

In recent years, matter-wave interferometry has attracted growing attention due to its unique suitability for high-precision measurements and the study of fundamental aspects of quantum theory. Diffraction and interference of matter waves can be observed not only at a spatial aperture (such as a screen edge, slit, or grating), but also at a time-domain aperture (such as an absorbing barrier, or “shutter,” that is being periodically switched on and off). The wave phenomenon of the latter type is commonly referred to as “diffraction in time.” Here, we introduce a versatile, exactly solvable model of diffraction in time. It describes time evolution of an arbitrary initial quantum state in the presence of a time-dependent absorbing barrier, governed by an arbitrary aperture function. Our results enable a quantitative description of diffraction and interference patterns in a large variety of setups, and may be used to devise new diffraction and interference experiments with atoms and molecules

FCStone Conversion to a Public Corporation

FCStone Group (FCS) is a publicly held corporation that converted from a cooperative to a private corporation in 2005, and then converted to a public corporation in 2007. It is an integrated commodity risk management company that provides risk management consulting and transaction execution services to commercial commodity intermediaries, end users, and producers. This case study focuses primarily on the period from the first conversion in 2005 to six months after the public offering in March 2007. Because the financial benefits received by each of the cooperative owners of FCS are dependent on the timing of their sale of FCS stock, stock price information and benefit estimates are provided up to early November 2008.Agribusiness,

The great outdoors: how a green exercise environment can benefit all

The studies of human and environment interactions usually consider the extremes of environment on individuals or how humans affect the environment. It is well known that physical activity improves both physiological and psychological well-being, but further evidence is required to ascertain how different environments influence and shape health. This review considers the declining levels of physical activity, particularly in the Western world, and how the environment may help motivate and facilitate physical activity. It also addresses the additional physiological and mental health benefits that appear to occur when exercise is performed in an outdoor environment. However, people's connectedness to nature appears to be changing and this has important implications as to how humans are now interacting with nature. Barriers exist, and it is important that these are considered when discussing how to make exercise in the outdoors accessible and beneficial for all. The synergistic combination of exercise and exposure to nature and thus the 'great outdoors' could be used as a powerful tool to help fight the growing incidence of both physical inactivity and non-communicable disease. © 2013 Gladwell et al.; licensee BioMed Central Ltd

Transfer of molybdenum disulfide to various metals

Sliding friction experiments were conducted with molybdenum disulfide single crystals in contact with sputter cleaned surfaces of copper, nickel, gold, and 304 stainless steel. Transfer of the molybdenum disulfide to the metals was monitored with Auger electron spectroscopy. Results of the investigation indicate molybdenum disulfide transfers to all clean metal surfaces after a single pass over the metal surface with film thickness observed to increase with repeated passes over the same surfaces. Large particle transfer occurs when the orientation of the crystallites is other than basal. This is frequently accompanied by abrasion of the metal. Adhesion of molybdenum disulfide films occurred readily to copper and nickel, less readily to 304 stainless steel, and even less effectively to the gold, which indicates a chemical effect

DNA sensing by electrocatalysis with hemoglobin

Electrocatalysis offers a means of electrochemical signal amplification, yet in DNA-based sensors, electrocatalysis has required high-density DNA films and strict assembly and passivation conditions. Here, we describe the use of hemoglobin as a robust and effective electron sink for electrocatalysis in DNA sensing on low-density DNA films. Protein shielding of the heme redox center minimizes direct reduction at the electrode surface and permits assays on low-density DNA films. Electrocatalysis with methylene blue that is covalently tethered to the DNA by a flexible alkyl chain linkage allows for efficient interactions with both the base stack and hemoglobin. Consistent suppression of the redox signal upon incorporation of a single cytosine-adenine (CA) mismatch in the DNA oligomer demonstrates that both the unamplified and the electrocatalytically amplified redox signals are generated through DNA-mediated charge transport. Electrocatalysis with hemoglobin is robust: It is stable to pH and temperature variations. The utility and applicability of electrocatalysis with hemoglobin is demonstrated through restriction enzyme detection, and an enhancement in sensitivity permits femtomole DNA sampling

Sources of Financial Stress in Agricultural Cooperatives

Financial stress in agricultural cooperatives may be due to a combination of three factors: inadequate profitability, excessive debt, or high interest rates. This paper uses an analytical technique to determine the relative degree of financial stress in agricultural cooperatives attributable to each factor. Roughly 30 percent of agricultural cooperatives in our sample suffered financial stress from 1987 through 1992. The analysis indicates that the greatest portion of financial stress, 54 percent, originated from low earnings. High interest rates accounted for roughly 24 percent of the financial stress while leverage accounts for the remaining 22 percent. The results also indicate that smaller cooperatives are more than twice as likely to face financial stress than larger cooperatives. Small cooperatives are more likely to face profitability problems whereas large cooperatives are more likely to face debt and interest rate problems.Agribusiness, Agricultural Finance,