Optical Dipole Trapping beyond Rotating Wave Approximation: The case of Large Detuning

We show that the inclusion of counter-rotating terms, usually dropped in evaluations of interaction of an electric dipole of a two level atom with the electromagnetic field, leads to significant modifications of trapping potential in the case of large detuning. The results are shown to be in excellent numerical agreement with recent experimental findings, for the case of modes of Laguerre-Gauss spatial profile.Comment: 13 pages, 2 figure

The design of a long range megatransport aircraft

During the period from August 1991 - June 1992 two design classes at Purdue University participated in the design of a long range, high capacity transport aircraft, dubbed the megatransport. Thirteen Purdue design teams generated RFP's that defined passenger capability and range, based upon team perception of market needs and infrastructure constraints. Turbofan engines were designed by each group to power these aircraft. The design problem and the variety of solutions developed are described in an attached paper

A study of material damping in large space structures

A constitutive model was developed for predicting damping as a function of damage in continuous fiber reinforced laminated composites. The damage model is a continuum formulation, and uses internal state variables to quantify damage and its subsequent effect on material response. The model is sensitive to the stacking sequence of the laminate. Given appropriate baseline data from unidirectional material, and damping as a function of damage in one crossply laminate, damage can be predicted as a function of damage in other crossply laminates. Agreement between theory and experiment was quite good. A micromechanics model was also developed for examining the influence of damage on damping. This model explicitly includes crack surfaces. The model provides reasonable predictions of bending stiffness as a function of damage. Damping predictions are not in agreement with the experiment. This is thought to be a result of dissipation mechanisms such as friction, which are not presently included in the analysis

IS THE PROFIT MOTIVE AN IMPORTANT DETERMINANT OF GRAZING LAND USE AND RANCHER MOTIVE?

We build our economic models and estimate grazing policy impacts based on the standard economic model of profit maximization. Yet, over 30 years of research and observation has shown that, for many, consumptive and quality of life values are the most important reasons for the purchase of western ranches. Ranch buyers want an investment they can touch, feel and enjoy, and they have historically been willing to accept low returns from the livestock operation. Profit maximization appears to be an inadequate model for explaining rancher behavior; in estimating what impacts altered public land policies will have; and in de-scribing grazing land use and value. In this study, only 27% of the value of New Mexico ranches in the most productive rangeland areas was explained by livestock production potential. Economists and policy-makers must take the influences of both traditional livestock production and quality of life values into ac-count when determining appropriate policies for western rangelands.Land Economics/Use, Livestock Production/Industries,

Domiciliary occupational therapy for patients with stroke discharged from hospital: randomised controlled trial

OBJECTIVE: To establish if a brief programme of domiciliary occupational therapy could improve the recovery of patients with stroke discharged from hospital. DESIGN: Single blind randomised controlled trial. SETTING: Two hospital sites within a UK teaching hospital. SUBJECTS: 138 patients with stroke with a definite plan for discharge home from hospital. INTERVENTION: Six week domiciliary occupational therapy or routine follow up. MAIN OUTCOME MEASURES: Nottingham extended activities of daily living score and "global outcome" (deterioration according to the Barthel activities of daily living index, or death). RESULTS: By eight weeks the mean Nottingham extended activities of daily living score in the intervention group was 4.8 points (95% confidence interval -0.5 to 10.0, P=0.08) greater than that of the control group. Overall, 16 (24%) intervention patients had a poor global outcome compared with 30 (42%) control patients (odds ratio 0.43, 0.21 to 0.89, P=0.02). These patterns persisted at six months but were not statistically significant. Patients in the intervention group were more likely to report satisfaction with a range of aspects of services. CONCLUSION: The functional outcome and satisfaction of patients with stroke can be improved by a brief occupational therapy programme carried out in the patient's home immediately after discharge. Major benefits may not, however, be sustained

Method and apparatus for aligning a laser beam projector Patent

Laser beam projector for continuous, precise alignment between target, laser generator, and astronomical telescope during trackin

Method of directing a laser beam with very high accuracy

System will collimate and direct an argon laser beam with high angular tracking accuracy at objects on the moons surface. It can be adapted to missile and satellite tracking

Traveling-wave tube circuit simplifies microwave relay

Circuit with a sawtooth-modulated traveling-wave tube, which acts as a frequency converter and as an amplifier, simplifies microwave transmission. Lower power losses and reduced size and weight are also realized in this circuit

Slow light in degenerate Fermi gases

We investigate the effect of slow light propagating in a degenerate atomic Fermi gas. In particular we use slow light with an orbital angular momentum. We present a microscopic theory for the interplay between light and matter and show how the slow light can provide an effective magnetic field acting on the electrically neutral fermions, a direct analogy of the free electron gas in an uniform magnetic field. As an example we illustrate how the corresponding de Haas-van Alphen effect can be seen in a neutral gas of fermions.Comment: Slightly updated. Phys. Rev. Lett. 93, 033602 (2004

Is the squeezing of relic gravitational waves produced by inflation detectable?

Grishchuk has shown that the stochastic background of gravitational waves produced by an inflationary phase in the early Universe has an unusual property: it is not a stationary Gaussian random process. Due to squeezing, the phases of the different waves are correlated in a deterministic way, arising from the process of parametric amplification that created them. The resulting random process is Gaussian but non-stationary. This provides a unique signature that could in principle distinguish a background created by inflation from stationary stochastic backgrounds created by other types of processes. We address the question: could this signature be observed with a gravitational wave detector? Sadly, the answer appears to be "no": an experiment which could distinguish the non-stationary behavior would have to last approximately the age of the Universe at the time of measurement. This rules out direct detection by ground and space based gravitational wave detectors, but not indirect detections via the electromagnetic Cosmic Microwave Background Radiation (CMBR).Comment: 17 pages, 4 Postscript figures, uses revtex, psfig, to be submitted to PRD, minor revisions - appendix B clarified, corrected typos, added reference